Chirality- and size-dependent elastic properties of a single-layered graphene sheet
Original Research Article
Pages 5 – 8
Zh. Wang，Zh. Yu，X. Sun，Y. Wang，L. Xu
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Abstract
This article mainly uses a structural mechanics approach to analyze the elastic properties of a single-layered graphene sheet (SLGS). Besides, the space frame structure is also adopted to model the interatomic forces of the carbon–carbon bonds. By means of the finite element method, the elastic properties of SLGS on the basis of different chirality and size are measured. According to the results, the elastic properties of SLGS are size- and chirality-dependent, which is in consensus with the literature.

Application of a MEE-rock debris separation technique in deep hole bench blasting
Original Research Article
Pages9 – 14
M. Zhao, J. Zhang, Zh. Lei, Q. Kang
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Abstract
In order to solve the problem of water in boreholes which influences the blasting effect in open pit deep hole bench blasting, an isolator was designed for separating the mixed emulsion explosive (MEE) from rock debris, based on the principle of fluid dynamics. The finite element software ANSYS/LS-DYNA was applied to simulate the posture adjustment of the isolator in the process of falling. The result showed that the designed isolator could meet the purpose of separating MEE from rock debris. Simulation experiments in dry and wet borehole models with and without isolator were performed, and the results showed that the isolator can avoid the explosive misfire caused by mixing of MEE and rock debris, increase the utilization rate of MEE, improve the blasting effect, and meet the purpose of lowering the blasting cost.

Evaluation of motor function based on self-correction analytical hierarchy process
Original Research Article
Pages 15 – 19
X. Li , X. Wang1
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Abstract
In the evaluation of clinical rehabilitation functions, different experts will have different views. In order to be able to consider the expert opinions, in this paper the contents and methods of upper limb motor function evaluation were studied, and the evaluation index system was established. Quantitative evaluation of the evaluation index of motor function was carried out, and different evaluation criteria were provided for different evaluation indexes. The method of SFAHP (Self-correction Fuzzy Analytical Hierarchy Process) based on elemental classification was used to evaluate the rehabilitation process of hemiplegia upper limbs. The hierarchical model and evaluation system of evaluation index were established, and the evaluation model of hemiplegia upper limb motor function was established. Systematic analysis method was used to evaluate the feasibility and effectiveness of SFAHP method in the evaluation of upper limb rehabilitation. The evaluation results were consistent with the results of clinical motor function evaluation.

Biological conversion of H2 and CO2 into CH4 at room temperature and atmospheric pressure: a promising approach for reducing CO2 emissions and increasing biomethane production
Original Research Article
Pages 20 – 23
B.Yang, Q. Wang, X. Zhao, Ch. Wang, J.Liu, H.Yang, Sh. Liu, F. Yin, W. Zhang
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Abstract
An inoculum of methane-fermented active sludge was used to enrich hydrogenotrophic methanogens, by culturing using a gas mixture of H2, CO2 and N2 as the substrate. Culturing was performed at room temperature and atmospheric pressure and the types and changes of methanogenic archaea in the active sludge before and after the tests were characterized. The results showed that the highest yield of CH4 obtained was 258 mL from 3L of gas mixture, representing 51.6% of the theoretical maximum. The archaeal population present in the inoculum at the start of the experiment was dominated (84%) by the obligate acetotrophic Methanosaeta, which was reduced to 64% at the end of the experiment. In contrast, Methanosarcina, which is capable of using H2 and CO2, doubled from 8% in the original inoculum to 16% at the end. These experiments demonstrate that cultivation by gas cycling can realize bioconversion of H2 and CO2 into CH4.

Theoretical and experimental study on the safety chemistry of separation of oil/water transition layer by oxidation of chlorine dioxide
Original Research Article
Pages 24 – 28
J. Dong, L. Zhu, D. Gu, H. Sheng, Ch. Yan, B. Wang
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Abstract
The safety chemistry of ClO2 oxidative treatment of an oil/water transition layer was studied and evaluated by theoretical calculation and experiments. The theoretical analysis indicated that the unsafe factors were recognized as the difference of overpressure during the oxidation process, which originates from the decomposition of ClO2 and the release of gas from the oxidation of the reduced substances in the layer. The experimental results showed that the process pressure increased to a quite high value with the highly concentrated ClO2, and the overpressure caused an increase in the reactive temperature. Based on these data, some suggestions were presented for the safe production. The latter should ensure that the decomposed gas from chlorine dioxide leaves the atmosphere smoothly if the reaction process is an open system. ClO2 should be used at temperatures as low as possible, and the pressure control should be as stable as possible. This study provides safety control of the oxidation performance of chlorine dioxide, and efficient resolution of the settling tank oil/water transition layer with thickening, low-quality crude oil and high water quality.

Study of the mechanism of magnetron sputtering of hybrid bonded diamond as carbon film coating for the surface of cavity structures
Original Research Article
Pages 29 – 32
D. Wang, B. Hu
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Abstract
The carbon film bonding method is an sp3 and sp2 hybrid key combination. Compared with common diamond-like carbon (DLC) films for multi-contour cavity structures, magnetron sputtering has many advantages in coating DLC films, such as high hardness, low friction coefficient, corrosion resistance, good optical transmission, etc. However, there are some problems, e.g., non-uniform film thickness and low attraction force between film and substrate. In this research paper, some strategies were developed to solve the above problems: (1) multiple rotating cylindrical magnetron sputtering targets were installed to improve the efficiency and uniformity of films; (2) gradient composite membrane structure was used to improve the poor adhesion between film and substrate and to solve the problem of easy peeling of the single film from the substrate. Based on the above strategies, a uniform DLC film of compact thickness and excellent chemical performance was coated on the complex inner cavity wall of the multi-contour cavity structured product.

Research on the moisture content of adjacent soil layer affecting the failure behavior of soil and the uplift bearing capacity of the MEEP pile
Original Research Article
Pages 33 – 28
Y. Qian1, D. Teng, T. Lu, R. Wang
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Abstract
Using ANSYS software, an analysis model is established for a Multi-Extruded-Expanded-Plates pile (MEEP pile) in different soil layers under vertical tension. The effect of the moisture content of the adjacent soil layer (sandy soil) below and above the bearing plate on the failure behavior of soil surrounding the piles and the uplift bearing capacity of the single pile at the same time is studied. The model improved the calculation mode of uplift bearing capacity of the single pile, which provides a theoretical basis for engineering design of a MEEP pile.

Photo-induced toxicity in the rotifer Branchionus plicatilis by anthracene (ANT) in absence and presence of UV irradiation and mechanisms underlying observed effects
Original Research Article
Pages 39 – 43
C. Gao, X. Zhang, N. Xu, X. Tang
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Abstract
Anthracene, a polycyclic aromatic hydrocarbon (PAH), undergoes a series of chemical reactions by absorbing ultra-violet (UV) light, and is potentially phototoxic to aquatic organisms. The aim of this study was to investigate the effects of photo-induced toxicity of anthracene (ANT) alone or in combination with UV radiation on Branchionus plicatilis physiological and metabolic functions such as fecundity, reproductive cycle, age-specific survival rate, spawning rate and reproduction rate. The mechanisms underlying ANT-induced phototoxicity were examined by measuring oxidative stress parameters including reactive oxygen species (ROS) and malondialdehyde (MDA) content, activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione S-transferase (GST) and levels of glutathione (GSH). The results showed the following: (1) Compared with single UV-treated and single anthracene-treated groups, the two examned concentrations of anthracene (0.4 μg/L and 4 μg/L) under UV radiation significantly inhibited individual fecundity, shortened the reproductive cycle, and delayed or suspended the arrival of reproduction peak, life cycle parameters of B. plicatilis such as net reproduction rate (R0), life expectancy (E0), generation time (T), and intrinsic growth rate (rm).The reproductive capacity of the rotifers was lowered. (2) Under UV radiation, ANT significantly increased ROS and MDA content, leading to changes in activity of antioxidant enzymes. The activity of SOD and GPx decreased within the first 24 h while the activities of SOD, CAT, GPx, GST and GSH were reduced. GSH content was lowered after 48 h. Hence, ANT produced photo-induced toxicity on the reproductive capacity of B. plicatilis. Under UV radiation, ANT was more potent in disturbing antioxidant mechanisms resulting in diminished survival rate, reproduction and growth of B. plicatilis.

Diamond green dye adsorptive removal from water by carrot pulpy waste and potato peels
Original Research Article
Pages 816 – 822
R. Rehman, S. Alam, L. Mitu
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Abstract
Diamond green dye is an example of textile dye. In this study, Daucus carota (carrot) waste and Solanum tuberosum (potato) peels were used for dye removal from water. These are low-cost and commonly available materials. Their adsorption capacity for Diamond green dye was tested for the first time in this study for possible application on industrial scale water treatment. Optimum conditions for the removal of 25 ppm of Diamond green dye from 100 mL of synthetic wastewater by carrot pulpy waste were: 0.6 g adsorbent dose, pH 2.0, 40 min contact time, 30oC temperature and 150 rpm agitation speed. Using potato peels, the optimum conditions were: 0.4 g adsorbent dose, pH 1.0, 15 min contact time, 30oC temperature and 50 rpm agitation speed. Various conditions affecting the sorption of Diamond green dye from water were optimized by carrying out isothermal and kinetic studies. Isothermal studies indicated that chemisorptive mode is predominant over physio-sorption with maximum removal capacities for carrot waste and potato peels of 4.14 and 3.13 mg/g, respectively. Kinetic studies pointed to a pseudo-second order model. Both materials are suitable for bulk-scale removal of Diamond green dye from waste water streams.

Analysis of seepage characteristics of mine fractures based on geothermal utilization
Original Research Article
Pages 44 –48
P. Huang, Y. Zhang
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Abstract
This paper discusses the feasibility of using the fluid seepage characteristics to develop the underground thermal energy of the mine so as to combine the thermal hazards treatment of underground mine with the utilization of thermal energy. This paper puts forward the idea of using a high-pressure water pump to make cracks, and scouring the underground hot rock with cold water to get the heat energy. The main factor of the natural gushing water in the mine is found out. The causes and characteristics of the rock fracture deformation are analyzed. The data show that the rock fracture deformation and seepage relationship model can be established in the equivalent continuous medium state. In this paper, the relationship between fracture and seepage of rock mass is established, and the relationship between the flow of mine groundwater in rock mass and fracture deformation is obtained.

Supercritical CO2 extraction of organic matter from coal based on CO2 sequestration in deep coal seams
Original Research Article
Pages 49 – 54
H. Yu, R. Jiang, L. Chen
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Abstract
To evaluate the potential for mobilizing organic matter in coal during CO2 sequestration into deep coal beds, three coal samples of different rank were extracted with supercritical CO2 (Sc-CO2) using a self-assembled experimental device. The results showed that the extract yields decrease with the increase in coal rank, extraction temperature or coal particle size. Sc-CO2 extraction yields of lignite, bituminous and anthracite coal sample with a size less than 0.2 mm were 749, 218 and 201 mg/kg on a dry, ash-free basis at 40 ℃, respectively. Most of the small molecular organics in coal could be extracted at 40 ℃ with Sc-CO2, especially for low-rank lignite and high-rank anthracite. Although Sc-CO2 has a strong dissolution effect on small coal molecules, medium and high pressure (> 7 MPa) did not favor the diffusion of the extract from coal into the CO2-free phase. The main control factors in Sc-CO2 extraction of different rank coals may be different, e.g., the dissolved-organics quantity for lignite, the extraction temperature for bituminous coal, and the pore structure of coal for anthracite. These results demonstrate that Sc-CO2 dissolved small organic molecules trapped within coal will be mobilized with CO2, which is important to evaluate CO2 sequestration into deep coal seams

Evaluation of regional innovation ability based on green and low-carbon perspective
Original Research Article
Pages 55 – 58
H.Wang, L. An,X. Zhang
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Abstract
The aim of this paper is to evaluate the green innovation ability in China. The paper attempted to construct an index system from the three aspects of green innovation and used FAHP to evaluate the innovation ability. The evaluation result of the innovation input and output ability is "general", but the result of innovation environment is "poor ". Thus, countries and regions should pay more attention to the environment and energy factors in innovation in future.

Nitrogen transformation and biodiversity characteristics of fluvo-aquic soil from Hebei plain, China
Original Research Article
Pages 59 – 64
Y. Liu, H. Pang, X. Li, T. Gao, W. Zhao
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Abstract
To reveal the nitrogentransformations and the microbial community in the upper (0-20 cm) and low (20-40cm) layer of fluvo-aquic soil, the effects of microorganisms were investigated through drip irrigations by Chinese cabbage culture experiments. Three treatments of drip irrigation: groundwater (CK), groundwater with five types of bacteria (I#) and groundwater with one type of bacteria (A#) were conducted. 16S rDNA was used to detect the microbial community. Results suggested that drip irrigation with different bacteria significantly affected the nitrogen transformations in the upper soil layer. The total nitrogen (TN) concentration was the lowest (483.94 mg·kg-1) in soils using I# water compared with the other two treatments, suggesting that bacteria in I# water enhanced nitrogen transformation. The highest levels of nitrate in the 6th week of 17.45 mg·kg-1, 23.98 mg·kg-1 and 18.14 mg·kg-1 were found for I#, CK and A# water, respectively. The changes in ammonium concentrations were stable (0.19-0.34 mg·kg-1) in both soil layers treated with different drip irrigations in week 2-9.The TN, nitrate and ammonium concentrations in the lower layer soil showed the same trend but small variation changes compared with that in the upper soil layer. The phylum proteobacterium was most prominent among the bacterial phyla in soil, followed by actinobacteria, whereas thaumarchaeota and phyla proteobacteria were dominant among archaea and ammonia oxidizing bacteria, respectively. Nitrososphaera, cenarchaeum and candidatus were the most abundance genera across all soil samples for archaea community and nitrosomonas species were dominant asNH4+-N oxidizers in the soil.

Slicing filling principle and repeated mining key technology for extra-thick coal seams in small coal pit destroyed areas
Original Research Article
Pages 65 – 70
Ch. Li, X.-K. Sun, J.-H. Xu, Q.-L. Chang
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Abstract
Aiming to solve the problems of the efficiency of repeated mining technique in small coal pit destroyed areas, the principle of slicing filling and repeated mining was applied, and techniques were proposed for slicing grouting filling in small coal pit destroyed areas and reconstruction of cutting layers, spacer layers and support layers. Grouting filling eliminates potential safety hazards in small coal pit destroyed areas. Simultaneously, a complete area which is best for normal mining was built; the thickness and intensity of each layer were determined, and the filling materials and ratio of each layer were also provided. Field application proved that slicing filling and repeated mining achieves good results in safely recycled coal seams in small coal pit destroyed areas with high efficiency. Although the cost of coal is increased by 1.21 CNY (Chinese Yuan) per ton, the approach provides an innovative method for the safe and efficient backfill mining of coal resources in small coal pit destroyed areas and waste utilization in a mining area.

Pyrolysis characteristics and kinetic analysis of waste cooking oil
Original Research Article
Pages 71 – 76
B. Li, J. Li, H. Zhou, Y. Wei, H. Wang, J. Hu
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Abstract
The pyrolysis characteristics of waste cooking oil, pretreated by removing impurities and water, were studied by a thermal analysis technology at heating rates of 5oC, 10 oC and 20 oC /min. The pyrolysis mechanism function f(α) and kinetic parameters of waste cooking oil pyrolysis were determined by the Coats-Redfern method through TG curves. The results showed that the pyrolysis of waste cooking oil could be divided into three stages: volatilization of light components, pyrolysis of heavy components and crack and polymerization of the residue. A three-dimensional diffusion model of the Jander function 3D(n=2) was conformed to the pyrolysis process of waste cooking oil with the mechanism function f(α)=6(1-α)2/3[1-(1-α)1/3]1/2. The activation energy for the main pyrolysis stage of waste cooking oil pyrolysis increased with the increase in heating rate. The triglycerides in waste cooking oil firstly cracked into fatty acids, acroleins and fatty aldehydes. Then, at a temperature about 400-500 oC, the products of the first step decomposed to small molecules.

Limitations of measurements of supercritical CO2 sorption isotherms on coals with manometric equipment - an experimental case study
Original Research Article
Pages 77 – 82
H. Yu, R. Jiang, L. Chen
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Abstract
Accurate measurement of CO2 adsorption on coals, which is useful for laboratory estimation of CO2 sequestration potential in coal, has proven to be a complicated matter. A series of potential sources of error in CO2 sorption measurements is provided here. The paper investigates the effect of experimental parameters, coal swelling and tmperature control on the measurement of supercritical CO2 adsorption isotherms on coals. Accuracy of pressure and temperature sensors will obviously affect the determination of CO2 adsorption, which is caused by the great value of CO2 density change with pressure and temperature at a pressure of 8-10 MPa. The influnce of pressure- and temperature-sensors accuracy in the reference cell on CO2 adsorption can be reduced by improving the experimental method, but their effects in the sample cell are difficult to improve. Coal swelling at high pressure leads to an obvious increase in CO2 adsorption. A high error of supercritical CO2 adsorption on coal will be caused by the temperature gradient in the sample cell due to the higher Joule-Thomson coefficient of CO2 and the poor thermal conductivity of coal and CO2. The errors of pressure and temperature, coal swelling and control of experimental temperature will lead to negative adsorption and change in the shape of the adsorption isotherm, worse reproducibility and repeatability of supercritical CO2 adsorption.

Relationship between space structure characteristics and site environment of Pinus Yunnanensis secondary forests on Mopan Mountain in the middle of Yunnan, Southern China
Original Research Article
Pages 83 – 88
Y. Zhao, X. Duan, Sh. Shu
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Abstract
The influence on forest space structure by the site environment of Pinus Yunnanensis secondary forests, which are the main native species at the middle of Yunnan in China is discussed. Based on the analysis of site environment and forest space structure characteristics, the relationships between forest structure and site condition were analyzed using RDA sequencing. Results showed that there are big differences in forest non-space structure at each sample plot, the average diameter and height all displayed significant differences at most sample plots (P<0.05) and different distribution (P<0.05). Otherwise, in forest space structure, the average uniform angle index and neighborhood comparison at each sample plot were near to 0.5, which indicated that most forests had random distribution in the mean state. The interaction between non-spatial structure and spatial structure of forest stands was not equal, and the spatial structure was more influenced by the line length.

Breaking features of loading key strata based on deep beam structure in shallow coal seam and its limited span-to-depth ratio
Original Research Article
Pages 89 – 95
F. Wu, X. Sun, J. Li, Ch. Liu, Q. Chang, B. Chen
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Abstract
Based on the occurrence characteristics of loading key strata in a shallow coal seam, we built the mechanical model of the deep beam structure of the loading key strata under different boundary conditions. The features of first breaking and periodic breaking as well as the breaking span of the loading key strata considered as a deep beam structure were analyzed. The analytical solutions of elastic mechanics of stress components and displacement components upon first breaking and periodic breaking of the loading key strata more conformed to the real situations of breaking of overburden rocks of shallow coal seam during the exploitation as compared with analytical solutions of material mechanics and those of elastic mechanics of general long beams. The first and periodic breaking of the loading key strata usually belongs to tensile failure. Limited span-to-thickness ratio ε characterizes the stability of loading key strata, and it is affected by load, strength of rock mass and thickness of the loading key strata.

Test study on the thickness of the soil layer under the plate affecting the compression failure of the concrete expanded-plate pile
Original Research Article
Pages 96– 102
Y. Qian, Z. Liu, W. Tian, R. Wang
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Abstract
In this paper, the influence of the thickness of soil layer under the plate on the failure behavior of soil surrounding the pile and the bearing capacity of a single pile under vertical compression in the complex soil layer is studied. In the test study, the small model test method of undisturbed soil with a new half-section pile is adopted, which not only solves the question that by the original full-section pile the whole failure behavior of soil surrounding pile cannot be clearly seen, but also solves the defection that burring soil test cannot ensure soil characteristics according to the actual condition of the construction site. By comparing and analyzing the results of finite element analysis the reliability of the test results was checked. The study results will provide a reliable theoretical basis for the design and application of the concrete expanded-plate pile, promote the popularization and application of the concrete expanded-plate pile and look forward to achieve larger social and economic benefits.

Research on the environmental protection of magnetron sputtering coating for multi-contour cavity structure products
Original Research Article
Pages103 – 106
D. Wang, B. Hu
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Abstract
Although chemical coating is mature, with the increasingly serious environmental pollution, limited or prohibited production is inevitable. The common coating method could not be used for the contour cavity structure product as the structure of the product is too complex. Normally, the problem includes: (1) low target utilization rate, (2) not uniform film thickness, and (3) no dead cavity coating. In this paper, some strategies were used to solve the above problems: (1) Multiple rotating cylindrical magnetron sputtering targets were installed to improve the efficiency and uniformity of films; (2) Multiple magnetron sputtering targets and an auxiliary magnetic field were set to improve the plasma density of the vacuum coating chamber and the uniformity of the film on the inner cavity wall; (3) Appropriate magnetron sputtering process parameters were selected to improve the adhesion strength between the film and the substrate interface. Based on the above strategies, a uniform, compact and continuous composite film can be coated on the multi-contour cavity structure product. Magnetron sputtering is a physical vapor deposition method which not only meets the technical requirements of complex surface coating, but also abandons the pollution caused by chemical plating problems. It is an excellent green environmental protection process.

Study of the influence of Ca2+ content in soil on Brassica Chinensis L. crop yield under acid rain stress conditions
Original Research Article
Pages 107 – 112
Ch. Fang, T. Wu, J. Cong, J. Wang
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Abstract
With the rapid development of economy, the frequency and intensity of acid rains is increasing, which is a growing global environmental concern, especially in China. In recent years, techniques to protect the crop yield under acid rain stress conditions have become a focus of attention. In this study, Brassica Chinensis L., one of the typical crops in the northeast of China, was selected to examine crop yield under acid rain stress conditions. Based upon two series of simulation experiments, (1) growth and physiological characteristics of Brassica Chinensis L. were determined under different acid rain stress conditions, and (2) it was examined whether supplementation with additional Ca2+ to soil was able to protect Brassica Chinensis L. under these conditions. The results showed that additional Ca2+ in soil improved growth and physiological characteristics of Brassica Chinensis L. through the increased total and pectic acid Ca2+ concentrations in plants. Acid rain stress decreased the yield of Brassica Chinensis L, while additional Ca2+ administered to soil enhanced the yield. Data suggest that adding Ca2+ to soil was effective in preventing the actions of acid rain on Brassica Chinensis L. growth.

Study on fundamental polishing characteristics in chemical mechanical polishing of gallium arsenide (GaAs) wafer
Original Research Article
Pages 113 – 117
D. Yi, J. Li, J. Cao
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Abstract
Chemical mechanical polishing (CMP) experiments were carried out to evaluate the effect of the process parameters on the polishing characteristics of GaAs wafers. CMP of the GaAs wafers was conducted on a commercial polisher; the polishing slurry was freshly prepared from analytical grade materials prior to each experiment. The experimental results indicated that (1) the surface roughness Ra decreases on increasing the rotational speed of the polishing pad and polisher head, and polishing load; (2) the polishing load is one of the main factors that affect the total thickness variation (TTV). With the increase in the polishing load, the TTV of the wafer was reduced accordingly; (3) the material removal rate (MRR) increases on increasing of the rotational speed of the polishing pad, the rotational speed of polisher head, and the polishing load; the change of polishing load has the most obvious effect on the MRR.

Influence of kidney tonic formula on the hippocampal neurotrophic factors and proliferation and differentiation of neural stem cells in natural aging rats
Original Research Article
Pages 118 – 120
J. Yao, Q. Niu, L. Li, Y. Li, Y. Feng, S. Ma
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Abstract
The aim of this research was to explore the influence of the quantity of NGF and GDNF in hippocampus on the proliferation and differentiation of hippocampal neural stem cells (NSCs) in natural aging rats and the function of Zuogui pill and Yougui pill. Methods: SD rats were divided into Old group, Zuogui group and Yougui group. Young group (5 months) was set additionally. All rats were fed with common food and free drinking water. Old group was fed to 24 months old. From 20 months old, Zuogui group and Yougui group were fed with food mixing two formulas (0.675g/100g/d) accordingly for 4 months. Western Blot method was utilized to assay the protein expression of NGF, GDNF, nestin and ki-67 in rat hippocampal tissue. Results: compared with Young group, the protein expressions of NGF, GDNF, nestin and ki-67 were all down-regulated in rat hippocampus in Old group, P＜0.05; compared with Old group, the protein expression of NGF, GDNF, nestin and ki-67 were all up-regulated in both Zuogui group and Yougui group, P＜0.05. Conclusion: the change of protein expression of NGF and GDNF can influence the proliferation and differentiation of NSCs in hippocampus in aged rats, and Zuogui and Yougui pills can ameliorate these trends.

In vitro fluoride release from fluorinated elastic denture material
Original Research Article
Pages 121 – 124
Zh. Tang, X. Zhao
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Abstract
Elastic denture material has been routinely applied to replace missing teeth. Its physical and chemical properties, as well as its flexibility enable its application to cover concave abutment areas, reduce food impaction, and improve the retention of dentures. However, after long-term elastic prosthesis wear, the self-cleaning ability during the chewing process weakens, resulting in a drastically increased chance of local plaque deposition on the abutment and microecological imbalance, which can lead to caries and periodontal diseases. In this study, to effectively prevent and reduce the occurrence of caries around dental restorations such as dentures, different ratios of sodium monofluorophosphate (Na2PO3F or MPF) were added to the elastic denture material, and the time-dependent fluoride release process was investigated after soaking in artificial saliva at a temperature maintained at 37ºC. The elastic denture materials containing 0%, 3%, 5%, 10%, 15% and 20% (weight ratio) of MPF were soaked in100 ml and 200 ml of artificial saliva solutions at a constant temperature of 37ºC. The solutions were periodically replaced, and a 2 ml sample of each solution was tested just before replacement. The fluoride release rates and patterns were determined using the fluoride selective electrode method. All fluorinated elastic dentures released fluoride at different concentrations, and the higher the added fluoride content, the higher was the fluoride release. The elastic dentures with added MPF demonstrated an effective fluoride slow-release effect. The controlled release of fluoride can effectively prevent and reduce the occurrence of caries around dental restorations such as dentures.

Controlling the abnormal state in the Rb-E2F pathway involving microRNAs
Original Research Article
Pages 125 – 129
.L. L. Li, J.W. Shen, Z.L. Liu
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Abstract
Experiments have shown that microRNAs play an important role in regulating gene networks. They can orchestrate whole cellular programs by simultaneously regulating the expression of a group of genes. Restoring microRNAs to normal levels in cancer cells can reverse the aberrant cell growth. So understanding how to control the normal levels of microRNAs in the cancer cells is a critical step in controlling cancer. In this paper, a method to control microRNAs levels is presented by investigating the gene regulative network involving the Rb-E2F pathway and microRNAs (miR449); also, the influence of noises on the dynamical behaviour of the Rb-E2F pathway is studied by using a mathematical model. The results show that there is a relationship between noise density and system response. Through finding and defining the phenomenon of stochastic resonance it was found that the stochastic resonance can be controlled through the optimal noise intensity, and the microRNA levels can be controlled. These findings are propitious in providing a novel way to heal cancer.

Research progress in oil-field scale prevention techniques
Original Research Article
Pages 130 – 135
J. Dong, X. Sui, B. Wang, Y. Liu, Ch. Yan, L. Zhu, D. Yuan, L. Li
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Abstract
The presence of scaling poses significant issues in the production and recovery benefits of oil fields. This article reviews the causes of oilfield scales and elaborates on common scale prevention methods, including chemical technique, ultrasonic technique, electromagnetic technique, and metal coating technique. The paper describes the existing techniques in detail, lists their respective advantages and disadvantages, and proposes a technology variation that can reduce the formation of scales. This work is expected to contribute guidance in normal oil field production.

Bavachin antioxidant effects on the cardiac myocytes of mice in exhaustive exercise
Original Research Article
Pages 136 – 142
W.Y. Zhu, X. Yue, X. Lv, Ch. Yi, J. Liu
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Abstract
Bavachin is the main substance extracted from Psoralea corylifolia which is a widely used traditional Chinese medical herb. Studies have shown that bavachin may have a vital antioxidant role in exercise-induced myocardial mitochondrion injury, but the specific antioxidation effect of this herb still remains unexplored. Our study is dedicated to evaluate the antioxidant effect of bavachin in mice with one-off exhaustive swimming, and explore the underlying mechanisms. Bavachin (16 mg·kg-1) was orally administered to mice for 13 days before the forced swimming to exhaustion test. The average swimming time to exhaustion of bavachin-treated mice was prolonged by 56.5% (71.86±28.88 min) compared with that of the control group (45.86 ±12.09 min). Structural analysis showed that myofibrils in the experimental group were lined up in register, the number of mitochondria increased, the membrane structure was clear and kept intact. Malondialdehyde (MDA) contents of the experimental groups significantly decreased (p＜0.05) compared with the control group. The activity of H+-K+ ATPase, respiratory chain complex I (RCC I), cytochrome c oxidase (COX) and the levels of superoxide dismutase (SOD) of the experimental groups significantly increased (p＜0.05) compared with the control group. Therefore, this study provides a new idea about the protective mechanism of cardiac muscle mitochondria by using bavachin as a natural adjuvant antioxidant to improve the antioxidative levels in mice with one-off exhaustive swimming. These results provide scientific evidence that bavachin has a potential as an antioxidant agent for human beings such as athletes and elderly persons.

Study of the influence of karst water runoff on mining based on fuzzy mathematics
Original Research Article
Pages 143 – 146
A.J. Shao, L.Y. Zhao, S.W. Wang
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Abstract
Taking Fengfeng coal field as an example, the paper applies the fuzzy mathematics principle to the strength of karst runoff zone of Minmetals field partition. The frequency statistics method is adopted to define the membership degree, elevation, single well water inflow, karst rate, and hydration group classification. At the same time, considering the influence of the ionic concentration of karst water runoff intensity, the fuzzy comprehensive evaluation method is used for the calculation, and the results show that the strength of the karst runoff zone will affect the safety of mining. Karst water runoff intensity is proportional to the concentration of the ions. The relationship between runoff intensity and single well water inflow is most obvious. The biggest water inflow of the single well is in a strong runoff zone, and in a weak runoff zone it is very small, which provides decision basis for mine safety production planning. Minmetals is located in the Ordovician limestone strong runoff belt of Gushan east side, thus constituting a serious threat for deep coal seam mining. The research in this paper provides a theoretical basis for Minmetals deep seam mining from the weakest runoff.

Impact of quadric surface carrier on gas flow radial dispersion pattern in a vehicle catalytic converter
Original Research Article
Pages 147 – 151
B. Ding
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Abstract
In a conventional vehicle catalytic converter with flat-end carrier and common diffusion header, most of engine exhaust passes through a small-radius tubular part of the centre of the honeycomb carrier where the catalyst is rapidly deteriorated with high load and the honeycomb is easily fragmented on thermal stress. To improve the radial distribution of the exhaust gas by optimizing the structure of the converter is valuable in theory and practice for enhancing the conversion, service life, and reducing the cost. In this study, numerical simulation and experiment verification of the gas flow in an automotive catalyst converter with several quadric surface-shaped honeycomb carriers were performed based on ANSYS-CFD code and test, and the influence of the carrier fore-end types matching of diffusion headers on flow radial uniformity was studied. The effects show that cone-headed and sphere-headed honeycomb carriers improved the flow radial distribution especially in a cone-headed honeycomb carrier matching an enhanced diffusion header (EDH), thus the uniformity evaluation index can be increased by 29.4%–33.9%. The cone apex angle should be controlled between 60° and 90° so as to get comprehensive advantages of better flow distributional uniformity along desired radial reliability and small size of converter.

Influence of freezing and thawing cycles on bamboowood’s surface properties
Original Research Article
Pages 152 – 155
X. Liu, X. Guan, M. Guo, X. Wang, J. Lin
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Abstract
“Replacing wood by bamboo” is a research hotspot in the current field of wood science. Performing freezing and thawing cycles on moso bamboo chips and bamboo surface feature analysis before and after freezing and thawing cycles, results indicated that at freezing temperature of -16—-20oC, freezing time of 6 h, thawing time of 1.5 h, ice melting temperature of the bamboo chips of 60 oC, and 4 cycles, the surface glue absorption of moso bamboo could reach up to 11.01% with an increasing rate up to 92.41%. Plan B could be used to increase bamboo wood’s specific surface area by 267.06%. Pore volume was increased by 37.65%. Mean pore size was reduced by 62.87%. In cross section, the interval between primary tissues and vascular bundle was slightly enlarged, so that adhesive distribution would be evener. Relevant height of diffraction peaks in cellulose crystalline region was reduced by 106 cps and relevant crystallinity was lowered by 1.4%.

Synthesis and structure-activity relationships of a new highly selective rodenticide - brominated n-piperidine dibenzocycloheptoid
Original Research Article
Pages 156 – 158
F. Chen, Ch. Qu, J. Wang, L. Liu, Sh. Ning
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Abstract
With the widespread use of anticoagulant rodenticides, drug-resistant rats appeared, thus new types of rodenticides being needed. N-piperidine-10,11-dihydro dibenzo[a,d]cyclohepten (R) is a highly selective rodenticide but because of its low toxicity, it is not widely used. By adding bromine to the rodenticide molecule, the toxicity dramatically improves by keeping its high selectivity. Five different new brominated N-piperidine dibenzocycloheptoid rodenticides were synthesized in the present work. Toxicology experiments showed that the new rodenticides have excellent palatability and selectivity. Death time and death number relation graphs show that the distribution is moderate and is concentrated in 1 to 2.5 h. Brominated N-piperidine dibenzocycloheptoid is an excellent rodenticide.

Experimental study on dynamic shear modulus and damping ratio of CAS-1 lunar regolith simulant
Original Research Article
Pages 159 – 164
F. Yu, Sh.X. Chen, Y. Zhang, J. Li, Zh.J. Dai
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Abstract
In the paper an experimental study of the dynamic parameters of CAS-1 lunar regolith stimulant is carried out, and the law by which different void ratios and confining pressures influence the dynamic shear modulus G and the damping ratioλ is analyzed. The test results show that, in the case of real lunar surface under very low stress levels and large void ratio, the dynamic shear modulus G is smaller, and the damping ratioλ is larger; the dynamic shear modulus diminishes quickly and the damping ratio increases sharply along with the increase of dynamic shear strainγ. Using the Hardin-Drnevich Model, the paper comes to the average fitted curve of the normalized dynamic shear modulus G/Gmax and the normalized damping ratio λ/maxλ changing with γ on the conditions of different void ratios and confining pressures. The correlative equation between the maximum dynamic shear modulus Gmax, the maximum damping ratiomaxλ, the dynamic parameters such as the reference shear strain rγand the stress levelsσare discussed. Based on this, the range intervals of Gmax, maxλandrγwithin the coring and sampling depth (0~3m) of lunar regolith, as well as the recommended values of G/Gmax andλcorresponding to various shear strain are presented.

Experimental study on the soil-water characteristic curve of the unsaturated loess in East Gansu province
Original Research Article
Pages 165 – 171
T. Wang，Y.M Ding，X.W Zhao，B.G Liu，Y. Song
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Abstract
In order to study the soil-water characteristic curve (SWCC) of unsaturated loess in East Gansu province, the effects of initial dry density and net mean stress on the SWCC of unsaturated loess were studied by a unsaturated soil triaxial apparatus. The results showed that when the matrix suction was the same, the moisture content of samples decreased with the increase in net mean stress. The larger the initial dry density, the smaller was the moisture reduction rate, and the higher was the final moisture content. Through the Van Genuchten model it was found that the residual moisture content θr decreases with the increase in net mean stress; the numerical values of the fitting parameters α and n do not change significantly as the net mean stress increases. The initial dry density mainly has an effect on the parameters θr and α of SWCC while the parameter n is not much affected.

Temperature and wear characteristics of TBR tread rubber and its constitutive characterization
Original Research Article
Pages 172 – 177
L. Ma, H. Yin, Z. Wang, J. Wu, Z. Wang, Sh. Hu, Zh. Miao
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Abstract
An auxiliary heating device for rubber wheels is developed based on the Akron wear testing machine. The temperature dependence of the rubber wear is analyzed. The results demonstrate that the relationship between the wear and temperature can be described by a quadratic polynomial function. The wear resistance at high temperature is related to the glass transition temperature of the rubber. At high temperature, butadiene rubber (BR) exhibits higher wear resistance than natural rubber (NR) and styrene butadiene rubber (SBR), due to its higher glass transition temperature. In addition, the friction energy of the LAT100 wear is calculated by the finite element method. A power function relationship between the wear and the friction energy is obtained by fitting the test data. Finally, a comprehensive expression of the rubber wear as a function of temperature is set up based on the relationship between temperature, wear volume, and frictional energy. This work improves the thermo-mechanical coupling model of rubber wear, and provides a new theoretical basis for more accurate analysis of rubber wear.

Impact of electrical environment on wireless sensor communication
Original Research Article
Pages 178 – 185
B. An, W. Zhang
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Abstract
In order to ensure security and reliability of Internet of Things, electromagnetic disturbance issue in electrical environment is studied, where a wireless sensor is applied. Research on characteristics of electromagnetic disturbance in substations of different voltage levels and of different insulation types is carried out through field measurements. Simulation and field experiment of electromagnetic disturbance and communication obstruction produced by electrical equipment is performed to reveal impact on communication quality of wireless sensor..

Discriminating geochemical anomalies by geological-geochemical method: A case study on Nagan section of E’dong area in Wuxu ore field in Guangxi Province, China
Original Research Article
Pages 194 – 199
R.Ch. Zhou, J. Wu
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Abstract
The Edong Pb-Zn-Sb ore district is an important mineralized anomaly area in the Wuxu ore field, Guangxi province China. The secondary halo method was used to locate blind Pb-Zn-Sb ore bodies in the Edong district. A strong single Zn secondary anomaly was found across the F3 fault zone in the Edong ore district. Alteration features and trace element concentration of country rock along the F3 fault and the ore veins in the Edong mineralized district were compared to discriminate if the Zn secondary anomaly was caused by mineralization or not. The F3 fault zone did not underwent alteration as those associated with Pb-Zn-Sb ore veins. The country rocks across the F3 fault zone is characterized by strong Zn anomaly without Pb anomaly and the country rocks surrounding ore veins, on the other hand, have anomalies of Pb and Zn. Based on the above difference between the F3 fault zone and Pb-Zn-Sb veins in alteration features and geochemical anomaly of element association, together with the geochemical characteristics of galena, sphalerite, and stibnite during weathering, it is concluded that the strong single Zn anomaly around the F3 fault zone does not caused by mineralization, but rather by the absorption of zinc sulfate by clay mineral in the F3 fault zone. Our conclusion has been testified by drill hole. This work provides a clue for discriminating if a geochemical anomaly is caused by mineralization or not and is therefore very important for supervising ore exploration

Removal of p-chlorophenol in wastewater through catalytic ozonation using MnOx/Al2O3
Original Research Article
Pages 200 – 204
Y.S. Wan, D.W. Li
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Abstract
In order to study the effect of catalytic ozonation with MnOx/Al2O3 in wastewater purification, the effect of the catalyst MnOx/Al2O3 on the removal of p-chlorophenol from water samples was simulated. The results showed that the addition of catalyst for 10 min of reaction could improve the removal efficiency by 20.15% in comparison with ozone alone. The catalyst was prepared by the impregnation method with a 1.5 mol·L-1 precursor solution of manganese nitrate. The removal efficiency was good at a calcination temperature of 500oC, and the removal rate reached 81.75% after 20 min of reaction. The catalyst was stable, and the removal rate of the catalyst after repeated use was 70.12% after 20 min of reaction. The characterization results show that the surface of the catalyst MnOx/Al2O3 has a more active reaction platform than the carrier Al2O3, which is helpful to improve the catalytic activity.

Coordinated development of environment and tourism in China using grey relational analysis
Original Research Article
Pages 205 – 209
J. Zhao, Sh.M. Li
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Abstract
Coordinated development of tourism and environment is of great significance to the development of human society. The assessment of current development of tourism and environment in China using the theory of grey system established a relationship model for the coordinated development of tourism and environment. Based on the statistics of the development indicators of tourism and environment in China from 2007 to 2015, this paper analyzes the coordinated development of the relationship between them. The analysis results show that the correlation coefficient of tourism and environmental development indicators in China is 0.530, which has the same direction and positive correlation in general. Tourism receipts, domestic tourist arrivals and domestic tourism receipts are the strong correlation tourism development indicators of environmental development. International tourism receipts and international tourist arrivals account for 50% of moderate correlation tourism development indicators of environmental development. Total amount of the wastewater discharge and total number of nature reserve are the strong correlation environmental development indicators of tourism development. This shows that tourism development has an important influence on the environment.

Monitoring of distribution of mineral elements during cultivation of Auricularia auricula in northeastern China
Original Research Article
Pages 210 – 213
J. Ch. Zhang, X. H. Kong, Y. P. Ma, X. Y. Wang, H. Chen, P. Q. Zhang, D. Sh. Yu, X. D. Dai, Q. F. Ma , Z. H. Han
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Abstract
The aim of this study was to establish differences in mineral element levels in the mycelium substrate, fungal residues and different tidal fruiting bodies of Auricularia auricula. The distribution of mineral elements in the mycelium matrix and fruiting body was determined during the cultivation process, which would enable the determination of the physiological characteristics of A. auricula mineral nutrition status. Inductive coupled plasma optical emission spectrometry (ICP-OES) was used to measure 14 mineral element levels in the hypha matrix of fungal residues grown in three cultivation pilot areas. Data showed that the amounts of 3 mineral elements, such as potassium, boron and iron decreased while those of 6 elements including calcium, magnesium, and manganese increased. There were differences depending upon the experimental scenario. Evidence indicates that the growing fruiting bodies of A. auricula exhibit varying concentrations of mineral elements, which may be important for use as medicines to treat various diseases.

Experimental insights into a novel over-saturated brine cement slurry used in anhydrite formation
Original Research Article
Pages 214 – 219
L. Xu, H. Gao, J. Xu, M. Xu, X. Wang, F. You, Y. Long
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Abstract
Well cementing properties of anhydrite formation are always challenging, due to the negative impact of anhydrite on the stability of cement slurry. Design and development of certain cement slurry appropriate in anhydrite formation is always essential. In combination to anhydrite properties of Missan Oilfields, herein, systematic experiments were made to develop a special kind of weighted over-saturated brine cement slurry. The density of cement slurry was designed up to 2.36 g/cm3 to mitigate the plastic deformation of anhydrite formation. Dosages of key additives were optimized by evaluating performance of cement slurry. The results showed that the developed cement slurry had favorable properties such as appropriate rheology, good fluid loss control, short thickening time, right angle consistency, and rapid development of compressive strength. This work not only provides instructive information on a kind of novel weighted over-saturated cement slurry of anhydrite formation, but also extends an important category of cement slurries..

Study on polystyrene conformational changes in supercritical fluid anti-solvent process by small angle X-ray scattering
Original Research Article
Pages 220 – 223
Q. Huo, D. Li, Zh. Wu
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Abstract
A preliminary study of the polymer conformation in supercritical fluid anti-solvent process was carried out by the method of grazing-incidence small angle X-ray scattering at the station of Beijing Synchrotron Radiation Facility (BSRF). The experiments showed that in the continuous process of adding an anti-solvent, polymer chain stretching occurred from random coil to a curled sphere.

Dynamic analysis of aluminum flows in production stage in mainland China: 1996-2014
Original Research Article
Pages 224 – 227
Sh. Liu
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Abstract
This paper applies substance flow analysis (SFA) and stocks and flows framework (STAF) to conduct dynamic analysis of aluminum flows in the production stage in mainland China from 1996 to 2014. Key findings include: (1) aluminum production industry of China developed rapidly from 1996 to 2010, larger and larger scrap was recycled and reused, while almost all flows declined at various degrees from 2011 to 2014; (2) in bauxite mining process, resource efficiency indices did not rise but dropped slowly, and net import dependence indices increased little by little, from 0.019 in 1996 to 0.413 in 2014; (3) in alumina production and primary aluminum electrolysis processes, resource efficiency indices were both large and stable, basically above 0.9, and net import dependence indices declined generally and gradually; (4) although secondary aluminum increased sharply from 1996 to 2011, its proportion grew slowly, reached the maximum of 0.198 in 2010 and decreased after 2011. Therefore, ore dressing-Bayer method, tailing reelection technologies, intelligent use of scrap and Go-Out Strategy must be promoted at a large scale as soon as possible.

Double motor intelligent control system for industrial agitation based on Kingview and single chip microcomputer
Original Research Article
Pages 228 – 232
Y.J. Wang, K.Y. Wei, H.H. Liu
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Abstract
To overcome the uneven stirring problem of a conventional single motor and meet the high stability requirements in pulping process of semi-solid alloy slurry, a double motor intelligent control system based on Kingview and single chip microcomputer (SCM) is designed. The system mainly includes the motor and its driving circuit, the power circuit, speed and voltage current detection circuit, Kingview and SCM control system. The double motor operation can be controlled effectively so as to achieve precise control of the agitating speed. The proposed method is illustrated through the preparation of a semi-solid alloy slurry in the laboratory. The experimental results show that the system can precisely match the double-motor speed and achieve better results than a single motor stirring system.

Use of artificial neural networks for modeling the fabric temperature in heat setting processes
Original Research Article
Pages 233 – 237
M. Gu, X. Xu, W. Xiong, H. Pan, W. Dai
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Abstract
The objective of this paper is to investigate the temperature of fabric while doing heat setting, because the key parameters were hard to confirm using a physical model. Therefore artificial neural network (ANN) with four layers was adopted. The oven temperature, the size of fabric, the weight of fabric and time were selected as input variables as they have significant influence on the temperature of the fabric during heat setting process. Adam algorithm was adopted to optimize the efficiency and the speed of ANN training. The predicted and experimental values agree well, indicating that the ANN models yield a good prediction in heat setting process.

Effect of sorbent concentration on Pb(II) sorption on Mg-Al-EDTAlayered double hydroxides
Original Research Article
Pages 238 – 241
X.T. Wang, L.X. Zhao, L. Li, Q.F. Chen, Q. Li, J. Zhang
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Abstract
The sorption of Pb(II) on a Mg-Al-EDTAlayered double hydroxide (LDH) sample was investigated at different sorbent concentrations and the sorbent concentration effect (Cs-effect) was observed. The sorption isotherm and kinetic process at a given Cs value can be adequately described by the classic Freundlich model and a pseudo-second-order kinetic equation. However, the classic Freundlich model cannot describe the Cs-effect observed in the studied sorption system. We believe that the Cs-effect can be attributed to the deviation of the real sorption system from an ideal one. It was confirmed that the surface component activity (SCA) model can adequately describe the Cs-effect observed in sorption experiments.

Theoretical research on the moisture content of fine silty sand affecting the failure behavior of soil of the MEEP pile under vertical tension
Original Research Article
Pages 242 – 246
Y. Qian, S. Liang, R. Wang, X. Su
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Abstract
Due to its moisture content, fine silty sand has a certain influence on the failure behavior and bearing capacity of soil surrounding the MEEP pile. In this paper, using ANSYS software, an analytical model of the MEEP pile is built with the bearing plate embedded in the fine silty sand. By analyzing different models, the results for the moisture content affecting the failure behavior of soil surrounding the pile are compared in order to provide a reliable theoretical basis for the uplift bearing capacity calculation of the MEEP pile in the fine silty sand.

Study on the influence of the abrasion angle on the rubber abrasion performance at different scales
Original Research Article
Pages 247 – 251
Z. Wang, Sh. Hu, F. Zhang, L. Ma
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Abstract
Rubber abrasion experiments under different temperatures and angles were carried out using a high temperature rubber abrasion tester to study the influence of temperatures and angles on the rubber abrasion performance. Surface morphology images of rubber samples were obtained using a 3D measuring laser microscope and their corresponding surface characteristic parameters were then obtained including the arithmetic mean deviation of outline (Ra), the root mean square deviation of outline (Rq), the 3D arithmetic mean deviation (Sa) and the 3D root mean square deviation (Sq). The scale effect on roughness measurements of the rubber abrasion surface was also investigated and an optimal magnification multiple in the microscope was recommended based on the variation data of the line roughness and the surface roughness at various magnifications.