Search

Demand for copper is growing in the world,which makes it increasingly necessary to process low-grade ores and tailings that used to be considered as wastes. The development and application of bioleaching by acidophilic chemolithotrophic microorganisms, which obtain energy from the oxidation of sulfide minerals and use carbon dioxide for constructive metabolism, has been a major approach for processing the low-grade copper ores. In this study, mixed culture consisted of six iron and sulfur oxidizing microorganisms were used in leaching of flotation and acid-leaching tailings obtained from Zambia sulfide ores. The result showed that 62.7% and 61.7% copper were dissolved by bioleaching, while 53.8% and 57.4% by acid leaching in flotation and acid leaching tailings, respectively. In addition, mineralogical forms of copper were quite noteworthy since copper sulfide mineral extraction was significantly improved in bioleaching. XRD analysis showed wollastonite and diopside in acid tailing were undetectable after 23 days while others were difficult to be dissolved. No jarosite or sulphur was detected by XRD in residues. more...

In order to investigate the effect of initial proportions of microorganisms on chalcopyrite leaching, six typical bioleaching strains were used to rebuild different co-culture systems. According to their different energy use types,Acidithiobacillus ferrooxidansDX2012 (ferrous and sulfur),Sulfobacillus thermosulfidooxidnasDX2012 (ferrous and sulfur),Leptospirillum ferriphilumDX12 (only ferrous),FerroplasmathermophilumL1 (only ferrous),Acidithiobacillus caldusDX2012 (only sulfur),Acidithiobacillus thiooxidansA01 (only sulfur) were classified to construct four groups(cells): a, 1:1:1:1:1:1; b, 10:10:1:1:1:1; c, 1:1:10:10:1:1; d, 1:1:1:1:10:10. The results showed that leachate pH of consortium a, d firstly began to decline until stabilized at 1.4. On day 9th, Eh of consortium d began to sharply rise and finally stabilized at 720 mV. Compared with consortium a, b and c, copper concentration of consortium d increased to the highest level of 6000mg/L. All the evidence suggests consortium d is the best combination which held the highest leaching rate of copper. Real-time quantification polymerase chain reaction (RT-qPCR) was used to analyze the population dynamics during all the bioleaching process. Final microbial community structure of four consortia was trended roughly the same and consortium d was first to reach final community structure on day 27th. It is concluded that bioleaching co-culture system containing a higher proportion of sulfur-oxidizing bacteria works more efficiently. more...

Sulfur oxygenase reductase (SOR), which is thought to be an important enzyme involved in sulfur oxidation in many microorganisms, may play a key role in sulfur oxidation in Acidithiobacillusthiooxidans. Draft genome sequence of A. thiooxidans A01 indicated the presence of sulfur oxygenase reductase gene (sor). The complementary DNA fragment was speculated to encode a putative 311-aa full-length protein SOR. Structural analysis of SOR revealed that three cysteines located in the two conserved domains, C32 at V-G-P-K-V-C32 as well as C102 and C105 at C102-X-X-C105, might form the substrate activation and binding site. It was proposed that conserved motif H87-X3-H91-X23-E115 acted as ligands might combine with iron atom to constitute a mononuclear non-heme iron center, catalyzing the oxidation reaction of substrate. more...

The draft genome of newly isolatedAcidithiobacillus ferrivoransZB-1 and DX-1 were deciphered to obtain a comprehensive insight into the genetic information and to discover the cellular mechanisms during its high activity in low temperature environment. Genome analysis speculated thatAcidithiobacillus ferrivoransZB-1 and DX-1 could fix carbon dioxide through the Calvin cycle and other central carbon metabolism potentially, and may be able to absorb and utilize nitrate or nitrite in the environment. The related cryophylactic genes (CspD, CspE, Fad and FabG) and gene clusters in fatty acid synthesis were discovered and suggested to play a crucial role in cold resistance. more...

In the bioleaching process, many factors in ore, water and sediments are important contributors as driving forces to improve leaching efficiency. In this study, FeSO4·7H2O and S0as energy substrates were added to an oxide-rich, low-grade copper ore to explore the influence of biological and environmental factors on leaching efficiency. Mantel test results showed that the leaching rate was significantly correlated with biological and environmental factors with r values of 0.78 and 0.63 respectively, indicating that influence of biological factors were more significant. It cannot be ignored that environmental factors were important to construct the microbial community. Real-time quantification polymerase chain reaction (RT-qPCR) showed that the dominant and minor species wereA. caldusandA. ferrooxidans. Canonical correspondence analysis (CCA) made it clear that pH and ferrous concentration were crucial for shaping microbial community. All results are of great significant to gain the optimal leaching condition on Zambia oxide-rich, low-grade copper ore. more...

Extraction of zinc from sphalerite using bio-hydrometallurgical technologies has become more and more popular. This study used an artificial microbial community with five known microorganisms to examine the relationship among microbial diversity, composition, and function (e.g., zinc extraction rates) in sphalerite bioleaching systems with additional pyrite (SP), chalcopyrite (SC), or both (SPC). Real-time quantitative PCR (qPCR) analysis showed that additional pyrite or chalcopyrite changed the microbial community composition dramatically during the sphalerite bioleaching process. Shannon diversity index, compared with Sphalerite (0.109), showed an increase in SP (0.508), SC (0.536) and SPC (0.289) on day 30, and zinc extraction rates were enhanced by about 12.1%, 4.3% and 9.47%, respectively. Also, additional pyrite or chalcopyrite made ORP and the concentrations of Fe3+, Zn2+ and H+ increased, which were the main factors on shaping the microbial community composition by Mantel test analysis. We developed a unitary model, showing that additional pyrite or chalcopyrite increased the microbial community diversity. more...

To optimize the prescription of tanshinone IIA lipid microspheres by central composite design method, and evaluate the quality. Through evaluating average particle size, stability constant and the encapsulation efficiency of the lipid microsphere to investigate the concentration of the egg yolk lecithin and the poloxamer and the percentage of Soybean oil in the total oil phase which may impact the properties of tanshinone IIA lipid microsphere. Building the mathematic relation between the index and factor by the binomial expression, according to the best mathematical model of the evaluation indicators to describe response surface and then to use response surface method to predict the best prescription which will be analysed. According to the prescription optimization to prepare tanshinone IIA lipid microsphere and evaluate its quality. The results showed that each index of the binomial equation fitting is good, the correlation coefficient of the average particle size, stability constant and the encapsulation efficiency are 0.97, 0.92 and 0.84 respectively. The optimized prescription is as follows: egg yolk lecithin1.38 g, F68 0.19 g, LCT 2 g, MCT 18 g, all the indexes of the optimized prescription are similar to the target values. more...

A method of simulation modeling and virtual presentation of river evolution was proposed. The method used a variable scale modeling method to generate virtual environment and the data model of irregular triangle network to build the river channel. The virtual environment and the river channel are unified with seamless splicing algorithm to enhance the sense of immersion. And then digital river simulation platform was developed. It displayed the erosion and deposition of river channel with color mapping and presented an efficient algorithm to analyze the change of section shape. The proposed method is validated by application in analyzing the sediment deposition and erosion of Chongqing reach of Yangtze River. more...

Microstructures of 9Ni steel quenched at different temperatures were obtained, and a simulated tempering at different temperature was implemented with the DIL850A dilatometer, then the effect of initial microstructure before tempering on the formation of reversed austenite was studied. Results show that the formation of reversed austenite during tempering becomes easier with the decrease of quenching temperature and the increasing of tempering temperature, but the stability may deteriorates with the rapid increasing of reversed austenite in content. Overall, the amount of reversed austenite mainly depends on the tempering temperature, and its formation rate is affected by the quenching temperature because refined quenching microstructure can promote the formation of reversed austenite observably. more...

The purpose of this study was to establish a relationship between the physical properties of powder and its behavior during high shear granulation. Andrographis extract was utilized as a model drug and microcrystalline cellulose (MCC) and soluble starch were selected as excipients. The extract was mixed with different excipient with the ratio 1:0.5, 1:1, 1:2 by weigh, respectively. The granules were prepared by using high shear granulation. The result of HSG was evaluated by monitoring such responses as granule yield, the ratio of Lumps and Fine. The effect of physical properties on granulation behavior was analyzed through stepwise regression. The results showed that angle of repose, moisture content, pore volume, and density were the main factors linked to the granulation. The main physical properties of extract powder were the important factors for high shear granulation, and statistical analysis identified the trends that interpreted in light of physical models of high shear granulation. more...

This study mainly explores local residents’ cognition toward the impact of holding sport events on the environment. The population for this study is 18-65 year-old residents of Neimen, the place holding Song-Jiang Jhen Battle Array event. Out of 400 survey questionnaires distributed during and after the advent of end of Neimen Song-Jiang Jhen Battle Array event, 306 usable responses were received from participants, indicating a high valid response rate of 76.5%. The results show that (1) residents’ gender and educational background do not exert significant differences among cognition toward positive and negative environmental impacts; (2) younger residents are found to show higher cognition toward positive and negative environmental impact; (3) unmarried residents exert higher positive environmental impact than married residents; (4) residents who support future re-organization of this event are proven to have higher positive environment impact cognition than those who do not; and (5) local residents obviously support the re-organization of Neimen Song-Jiang Jhen Battle Array event in the future. more...

In this study, researchers attempted to understand the types, frequency, and influences of enterprise business risks in swimming pool industry. Meanwhile, it was to explore whether there exist significant differences between different employee characteristics. Questionnaire survey was used to collect data, 304 valid questionnaires were obtained and valid rate was 76%, from employees of swimming pool. The results of this study were as follows :There were eight enterprise business risk types, including financial risk, disaster risk, responsible risk, policy and legal risk, human resource risk, organizational and strategic risk, operational risk, and industrial risk. industrial risk was the highest influence and financial risk was the lowest on business. Difference in employee’s age and educational level were found significant differences on influence eight dimensions of enterprise business risks. more...

Prepared Tanshinone IIA lipid microspere and evaluated its physicochemical properties in vitro and pharmacodynamics properties in vivo. Particle size, zeta potential, entrapment efficiency, quantitative determination and stability of Tan-IIA-LM with different dilution medium were investigated respectively by Dynamic Light Scattering, HPLC and Sephadex G-50 Microcolumn, and osmotic pressure and solution pH of Tan-IIA-LM were measured to evaluate the preparation comprehensively. Further more, comparative study of protection on focal cerebral ischemia/reperfusion injury in rats between Tan-IIA-LM and STS was studied.The results showed that average particle size was 203nm, zeta potential was-36.10 mV, content was 0.8mg·mL-1, entrapment efficiency was 93% and the Tan-IIA-LM which was diluted by 0.9% sodium chloride injection and 5.0% glucose injection were stable within 6 hours. Tan-IIA-LM had obvious protection on focal cerebral ischemia/reperfusion injury in rats. more...

Aimed at the common problems of small backfill space, hard to backfill, difficult to guarantee compaction quality in engineering, development law of fluidity and mechanical properties (unconfined compressive strength and cleavage strength) is analyzed by changing mix ratio of cement, fly ash and water. Fluidity is mainly controlled by water content. Range of fluidity is significantly different when water content is around 60％.Considering the effect of economy and strength, 4% cement content will be recommended. more...

The paper selects water price as a potentially effective socio-economic factor for the mitigation of conflict between socio-economic development and regional water resources in the Weihe River basin on basis of the driving mechanism research of socio-economic factors for water cycle, and evaluates the variation of socio-economic and hydrological variables by comprehensive simulation of economic system and water resources system by coupling of economic model CGE, water allocation model ROWAS and distributed water cycle model WEP. The results indicate that raising water price would bring down socio-economic development and regional water demand to some extent, but regional water resources tensions just reduce so slightly that corresponding schemes turn out to be not sufficient to deal with water crisis in the Weihe River basin. more...

Double Inverted pendulum as an important object of study on robotics and aviation field, is also a major platform for teaching and scientific research.Usually double Inverted pendulum modeling is usually will be linearized processing system, ignoring the effect of the angle of system. But the realization of double inverted pendulum is a nonlinear system, the angle affect the stability control. From the actual situation of double Inverted pendulum motion, double Inverted pendulum system of the input space is divided into 9 sub-space, by T-S fuzzy and feedback gain matrix to select the corresponding state equation, making the system more close to its dynamic performance. The multi mode adaptive control and T-S fuzzy method of combining the successful implementation of double inverted pendulum system simulation and real-time control.The number of rules they use far less than Mamdani fuzzy, but also successfully resolved the fuzzy control algorithm due to the presence of multiple variables and the resulting "rule explosion problem". more...

In this paper, linking with the basic principle of FCM (Fuzzy c-means clustering) algorithm, on the basis of theory research, the segmented partitions emerge when the state of the lives reaches an equilibrium. The artificial life approach is promising in image processing because it is inherently parallel and coincides with the self-governing biological process. Then combined with intensity-texture-position feature space in order to produce connected regions shown in the image, the final segmentation result is achieved at last. The experiment results prove that in the view of the sport image segmentation, this algorithm provides fast segmentation with high perceptual segmentation quality. more...

In the bioleaching of uranium ore, fluoride that ever accreted with the ore floats into solution, inhibiting the growth and metabolic processes of microorganism or even killing them, further reducing the efficiency of uranium leaching. In order to study the fluoride tolerance of the bioleaching microorganisms, five typical bioleaching strains includingAcidithiobacillus ferrooxidansATCC 23270,Leptospirillum ferriphilumYSK,Sulfobacillus thermosulfidooxidansST,Acidithiobacills thiooxidansA01,Acidithiobacills caldusS1 were selected to compare their growth fluctuation and their oxidation rate of iron or sulfur in the presence of different concentration of fluoride. The results showed thatAt. ferrooxidansATCC 23270 held the best fluoride tolerance, whileS. thermosulfidooxidansST took the worst. In order to explore the mechanism of microbial resistance to fluoride, whole-genome array (WGA) was used to analyze the genome-wide expression profiling ofAt. ferrooxidansATCC 23270 upon 4.8 mM fluoride stress. The results showed that gene categories closely related to fluoride tolerance include cell membrane, energy metabolism, transport and binding functions of proteins, DNA metabolism, cell processing, synthesis and transportation of protein and other functional and metabolic pathways. Most of the genes associated with iron-sulfur metabolic system ofAt. ferrooxidanswere highly expressed during 10 to 120 minutes, while in the long-term stress for 4 hours, the gene expression returned to normal level or even were down regulated. All these results provide useful information for further research on domesticating bacteria and increasing the efficiency of uranium leaching. more...

The leaching heap and acid mine drainage are two key nodes in a bioleaching system. This study aimed to investigate the microbial community structural and functional diversity between the two nodes in bioleaching system from Dexing copper mine in Jiangxi province, China. 16SrRNA gene cloning and metagenomic analysis consistently indicated that there were obvious differences on microbial community structural and functional diversity in the two nodes. In leaching heap, the dominant species was the heterotrophic bacterium Acidiphilium; while the dominant species was the autotrophic bacterium Acidithiobacillus in acid mine drainage. Seven bacteria species were found in both two nodes, while the unique bacteria species in leaching heap and acid mine drainage were eleven and eight, respectively. In relation to the microbial community function aspect, all contigs and singlets were annotated against the non-redundant protein database of NCBI and clustering analyzed with COG database. For the two nodes, the COG clustering results showed that the functional category abundances were different, though the functional categories were similar. And the great majority of ORFs were forecasted as function unknown. All the results meant that the microbial community structural and functional diversity of bioleaching system was not as simple as former thought. This study could provide a new meta-view of theoretical support to bioleaching process. more...

Using indigenous microorganisms in biomining processes assures few ecological distortions and less time consumption for adaptation. However, there is a debate as to whether an indigenous microbial community is more efficient than one composed of microbial strains selected for specific physiological traits. In order to provide thoughtful opinions in such a debate, a cross-comparison of six strains isolated from two different regions: Chambishi Copper Mine (Zambia) and Dexing Copper Mine (China), was conducted. Physiological properties and leaching performancesof Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum in pure and mixed culture were studied. The results showed that strains within species presented similar traits while copper resistance was not species-specific. In terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the exogenous. In addition, microbial community analysis revealed the different mixed culture shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains. more...

Microcrystalline Cellulose and Sarcandrae extract powder were used to study the relationships of pharmaceutical properties of powders before and after mixing operation. The theoretical values of the physical quantities of the binary mixture were calculated based on the random mixing theory. The measured values of angle of repose, hygroscopicity of binary mixture were larger than that of theoretical calculations. The effective Kawakita a and b for the MCC had changed by mixing operation. The parameters of blend powder reduced compared with MCC except D-1. The results suggested that the mixing behavior was not a complete random or simple superposition operation for the rough and sticky particles. The mixing process would create novel particles and the physical quantities of novel particles would changes regularly. more...

In reality, artificial factors are stronger in evaluating the comprehensive system during either the establishment of index system or the determination of the evaluation weight. In the paper it is discussed that rough set theory is applied to determine weight of comprehensive evaluation index, try to mine information from the data and to overcome the subjectivity of the weight setting in evaluating. We analyze a case using the designed program. more...

Microcrystalline Cellulose andHerba Sarcandraewere used to study the properties and relationship of powders before and after blending. The theoretical values of the physical quantities of the binary mixture were calculated based on the random mixing theory, The measured values of particle size specific surface area, pore volume and angle of repose of binary mixture had larger values than that of theoretical calculations. Whereas, tapped density and bulk density had a smaller value. The results suggested that the mixing behavior was not a complete random, arbitrary or simple superposition of the operation for coarse and sticky particles. The mixing process would create novel particles and physical quantities of novel particles exist regular changes. more...

The rural drinking water safety is an important issue for people's livelihood. For Luquan city, of Hebei province in China, drinking water was sampled through site investigation, and the water quality was analyzed used comprehensive index method. The results show that: the water type is IV in the investigation area, which is not suitable for drinking in a long time. The corresponding measures were proposed combined with the real conditions, which could provide theoretical guidance and policy reference for improvement of rural drinking water management mechanism. more...

Polyacrylate dispersants were synthesized by applying orthogonal array experiment method, among which the affecting factors include chain transfer agents: isopropanol (IPA). dodecyl mercaptan (DDM); initiators: benzoylperoxide (BPO), azobisisobutyronitrile (AIBN) and their contents, temperature, the content of acrylic acid and types of the monomers of solvation chains, of which poly (methacrylate), poly (ethyl acrylate), poly (butyl acrylate) were solvation chains. The optimal factors were obtained by comparing the viscosity decrease of the unsaturated polyester resin (UPR)/aluminum hydroxide (ATH) composites with different dispersants, and it showed that the dispersant with poly (butyl acrylate) as solvation chain whose length is around 7.0nm has the best result of improving rheological properties of UPR/ATH Composites and reducing systems thixotropy. more...

This study assessed the potential for the use of satellite derived rainfall in a data-scarce basin like the Black Volta in West Africa. Using a point to pixel approach, accumulations of ground measurements on daily, monthly and annual time scales were compared with accumulations derived from 0.1° resolution daily gridded satellite Rainfall Estimates (RFE). The results from the analysis of the RFE data showed monthly correlations ranged from 0.76 to 0.92 when compared with the rain gauge measurements. These results obtained, indicate “good” to “very good” in terms of correlation (r) for the monthly and annual datasets. The study found that the use of satellite derived rainfall, like the RFE from FEWSNET, in the basin would be of great benefit considering the difficulties in accessing data both locally and from the other riparian countries; but its analysis and use should be on the monthly and annual scales. more...

Ontology similarity calculation and ontology mapping are crucial research topics in information retrieval. Ontology, as a concept structure model, is also widely used in biology, physics, geography and social sciences. In this paper, we propose new algorithms for ontology similarity measurement and ontology mapping using supervised multidimensional scaling and multi-dividing technologies. Two experimental results show that the proposed new algorithm has high accuracy and efficiency on ontology similarity calculation and ontology mapping in certain applications. more...

For the friction stir welding technology of the low carbon steel, according to the character of the friction stir welding process, the researchers build a simplified heat input numerical model, and use the finite element analysis software ANSYS to simulate the transient temperature field distribution and the feature points of thermal cycle curve of the 4 mm Q235A steel in the butt joint. Comparing the simulation results and the feature point temperature curve measured by the thermocouple, the researchers verify the heat input model and simulation method is correct. It provides the scientific basis to select the right experimental parameters. more...

One new method is presented for computing engineering structure reliability by accelerating convergence based on the analysis of errors in the center point method and borrowing ideas form the merits of the other First-Order Second Moment (FOSM) methods. The accelerating convergence method is based on the first class Chebyshev polynomials. Firstly, the transformation relation of the first class Chebyshev polynomials and the power polynomials is given and expanded to vector formula. Secondly, the outstanding function approximate character of the first class Chebyshev polynomials can supply the high order information for the choosing of approximately surface. An example shows that the method presented in this article has well precision. Although the accelerating convergence method needs choose the format of the structural function properly for get the high precision results, the method can serve as an effective for engineering estimate owing to non-iterative formula and convenience. more...

To solve the problems in the construction of ecological environment, this paper studies the application, effect and investment of sprinkling irrigation and drip irrigation in the ecological environment construction by the field trials. The results show that the optimal irrigation technique for the restoration and reconstruction of ecological environment in desert area is the drip irrigation technique, followed by the point watering technology with portable hoses. more...

The interaction between tunnel surrounding rock and supporting structure has been deeply analyzed by using elastic-plastic theory, and the higher strength and durability of supporting structure made by selecting reasonable supporting structure and adopting high strength concrete as material has been proved. more...

The aim of the present study was to increase bioavailability after oral administration. In this study, Panaxnotoginseng saponins (PNS) was entrapped within the long-circulating nanoparticles (LCNs) by the multiple emulsion method. The PNS-LCNs were characterized in terms of size, zeta potential, morphology, thermal properties, drug entrapment efficiency (EE), and in vitro release of the PNS. In addition, the intestinal absorption of PNS-LCNs in vitro was investigated. The pharmacokinetics of PNS-LCNs following oral administration was determined over 72 h in male rats. It was found that the mean particle size and zeta potential of the PNS-LCNs were 147±4.5nm and −44.7±1.5mV, respectively, and the entrapment efficiency (EE) was 53.93%±0.69%. differential scanning calorimetry (DSC) indicated that PNS has different states in PNS-LCNs and original PNS. The release pattern of the PNS-LCNs followed the Weibull model. The release parameters (T50, TD) were observed to be higher for PNS-LCNs compared with original PNS (p< 0.01) in vitro release. The intestinal absorption study indicated that the intestinal permeability coefficient (Papp) of PNS-LCNs was higher than original PNS’s. The pharmacokinetics of PNS-LCNs was studied after oral administration to male rats, PNS-LCNs provided greater area under the concentration-time curve (AUC), higher plasma concentration (Cmax), longer mean residence time (MRT) and median time to maximum drug concentration (Tmax). LCNs could be used for improving permeability and increased bioavailability after oral administration of PNS. more...

Electrochemical behaviors of chalcopyrite, covellite, chalcocite and bornite in 9K medium at 65 °C were compared in this paper to verify they whether or not the intermediate products of chalcopyrite. The results confirmed that bornite, chalcocite and covellite are the intermediate products of chalcopyrite. Chalcocite and bornite can both oxidize to covellite. more...

Although surfactants have been considered in surfactant-aided soil washing systems, there is little information on the adsorption of the impact of surfactant on the adsorption of antibiotic, and this may have significant implications for the soil. In this study, Triton X-100 and SDBS were selected to study its effect on the sorption of Streptomycin sulfate from soil under equilibrium sorption. The adsorption of Streptomycin sulfate on soils in surfactant free and surfactant solutions of different critical micelle concentrations (CMCs) has been studied .The applied surfactant concentrations (X) ranged from below the (nominal) CMC to 5 times the CMC. For relatively water-soluble Streptomycin sulfate, the distribution coefficients with anionic surfactant (Kd*) deceeded those without surfactant (Kd), while non-ionic (Kd*) all exceeded those without surfactant (Kd). The Kd*/Kd ratios were used to evaluate the efficiency of surfactants and it was found that anionic surfactant is a better choice for remediation of contaminated soils whereas non-ionic surfactants leads to poor remediation efficiency. more...

Since the mechanical properties of the skin and the core of corn stalk are different significantly. The basal fourth internode of the corn stalk was chosen to do the compression test. The Maximum Force, the Compressive Strength, and the Modulus of Elasticity of the stalk skin and the core were obtained respectively. Then, the modulus of elasticity parallel to the direction of stalk skin fiber was calculated based on the measured data. The fiber reinforcement effect of the corn stalk skin was analyzed, combined with the mechanics of composites. Furthermore, the finite element model of corn stalk, regarded as composites, was constructed by ANSYS to simulate the compression test. The results showed that the simulation of reinforcement effect was well consistent with the value calculated by the mechanics of composite. more...

A large number of sensors have been used in the system to form a monitoring network through ZigBee protocol. The system can obtain the information through these sensors, and according to the information the position in question will be accurately located. The sensors connect to the monitoring network through a wireless module, and upload monitoring information in real time. The gateway is responsible for receiving the wireless sensor nodes to data storage, display and management, to achieve all base test point access to information, management, dynamic display and analysis and processing. This information will be display to the user with charts and text prompt manner in the monitoring software and it provides a variety of sound and light alarm information and message alarm information. more...

Friction Stir Welding (FSW) is a new and developing technology that has been used succefully in the joining of aluminum and aluminum alloys.To demonstrate the feasibility of the auxiliary power of Q235 steel friction stir welding, we used orthogonal test method to design auxiliary power FSW parameter,then welded 200mm×80mm×4mm of Q235 with the parameter. The result shows that the rotating 1200 r/min, the stay time 10s and the heating temperature 700 °C,the welding joint tensile strength can reach 332.19 MPa. Analysing the parameter fracture morphology,we found that the fracture is divided into three levels: the upper part is the ductile fracture; the middle part is the combination of the ductile fracture and the brittle fracture;the lower part is the majority of the brittle fracture, and exists the local ductile fracture. Analysing the microstructure,we found that welding joint is divided into the base zone, the heat affected zone,the thermo-mechanically affected zone and the stir zone,and the microscopic organization of every area is influenced by the heat and the force on the area. The microhardness of stir area improves 12% on average than the base’s.The microhardness of the heat affected zone and the thermo-mechanically affected zone decreases , comparing to the base’s. more...

Data mining is a kind of technology to analyze and treat information. From the current, as well as the future perspective of teaching reform in colleges and universities, the construction of question chain data center systems under the support of data mining technical by the means of question logic will enhance the effectiveness of the teaching of Ideological and political theory courses. more...

Based on transfer matrix method, the dynamic model is established for the spindle system of a composite grinder, and the modal analysis is carried out. The lower-order modal shape and natural frequency in the determined condition is obtained, and the effects of the support span and the support stiffness on the dynamic characteristics of the spindle system are analyzed. The spindle system’s structure is parameterized by the use of Matlab to improve the efficiency of the modeling and calculation. more...

In order to have a comparative investigation of the pollution and speciation characteristics of heavy metals between the gold and iron mine tailings of the upstream areas of Miyun Reservoir, the tailing samples from the typical gold and iron mines were analyzed. The total metal concentration is determined by acid digestion and the chemical fractionation of metal by the Tessier sequential extraction method. It is found that compared to background values of Beijing, the heavy metal in both gold and iron mine tailings is higher, while the heavy metal in gold mine tailings is higher than that of iron mine tailings, with Mn as an exception. Mercury is the most serious pollution element in gold mine tailings. Results of the sequential extraction suggest that the exchangeable of Cd exhibits the highest percentage of total metal in gold and iron mine tailings（15% and 6.5% of the total metal, respectively) among Cd, Mn, Zn, Cu, Pb, Cr. In the majority of iron mine tailing samples collected, large amounts of Cu were mainly associated with the organic form. The percentage of the bioavailable metals in both gold and iron mine tailing samples follows the order: Cd>Mn>Zn>Cu>Pb>Cr. more...

In this paper, a composite T-tail model is developed, including structural finite element model and aeroelastic model, and then structural optimization and aeroelastic analysis are made. Through two steps of structural optimization, and aeroelastic analysis, some valuable conclusions are achieved, which are useful for future composite T-tail design. more...

Wing stiffness, mainly including bending stiffness and torsion stiffness, is very important in aircraft structure design. In order to research the relation between wing stiffness and optimization results, this paper makes optimization analysis to a composite T-tail configuration and a composite flying wing configuration based on different wing stiffness constraints, and some valuable conclusions are achieved. more...

Measuring the tensile strength at the suture line of walnut shell is difficult by general fixtures. In this paper, a particular fixture was designed for measuring the tensile properties of the whole walnut shell based on the Pro/E software. The rigidities of main parts were checked by theory of mechanics combined with ANSYS. The results show that all the deformations were within the permissible scope, that is to say, this design is reasonable. Besides, four adjusting levers are designed to meet the size requirements of vary walnuts whose diameter is from 28mm to 40mm. Meanwhile, it can be conveniently located on the electronic universal testing machine. more...

On-line monitoring system of transformer oil chromatogram works in laboratory. Using the basic principles of gas chromatography (GC) of the broad spectrum, the system provides online-testing of dissolving gases from oil with a single gas chromatographic column and sensors with high sensitivity. The single-chip is used to collect the data and control transformers. The main controlling computer realizes the function of analyzing and managing the collected data, by which transformer fault can be judged. more...

This paper investigates the differences in the temporal heterogeneity of soil moisture between natural restoration ecosystem without disturbance (named as eco-1), restoration ecosystem with disturbance (named as eco-2) and shrubs ecosystem (named as eco-3) in red soil hillside fields. The probe soil moisture measured at 20 and 40 cm below the soil surface Hydrosense Portable Time Domain Reflectometry (TDR) system. The results showed that: (1) Daily measurements during a growing season showed significantly temporal interactions between vegetation and water. Soils under eco-2 (restoration ecosystem with disturbance) and eco-3 (shrubs ecosystem) were wettest at the start of the growing season but dries at the end; (2) The coefficient of variation of soil moisture content over time during the growing season was significantly higher in eco-2 than in eco-1, and at two depths beneath the soil surface (20 and 40 cm). more...

This study investigates the effect of moisture content on the residual bending strength after bending fatigue of T300/914 composite laminates immersed in water for 7 days and 14 days. Displacement-controlled three-point bending fatigue tests were conducted on specimens. After 40,000 cycles the fatigue test was stopped and the residual properties were measured on the tested specimens. Reduction in material strength was found to depend on the level of moisture content. Experimental results reveal that the moisture content in the laminates increased with immersion time. Compared to the unaged specimens, the residual bending strength after bending fatigue decreased by 6.67% and 37.04%, respectively. The residual bending strength and strength retention decreased with increased immersion time. more...

This study investigates the effect of moisture content on the bending fatigue properties of T300/914 composite laminates immersed in water for 7 days and 14 days. Displacement-controlled three-point bending fatigue tests were conducted on specimens. After 40,000 cycles the fatigue test was stopped and the properties were measured on the tested specimens. Reduction in material strength was found to depend on the level of moisture content. Experimental results reveal that the moisture content in the laminates increased with immersion time and that moisture absorption accelerated damage propagation in the composite. Hygrothermal ageing lowered the threshold level for the onset of fatigue. The experimental results were further validated by the supportive micrographs that illustrate different moisture content and their morphology before and after moisture absorption. more...

As the information collection device of the current domestic down-hole gathers less information and with low precision, the down-hole monitoring system with multi-parameter is designed in this paper. The system can be used on electric submersible pump to achieve two-way pressure, two-way temperature, leakage current, and vibration signals in real-time acquisition. Filtering the collected data, and using curve fitting algorithm on the pressure sensor for temperature compensation to ensure the accuracy of the data. Test results show that the system can withstand the harsh down-hole environments encountered in an oil well. Plus, the gathered data has high precision and timeliness. Accordingly, it reaches the expected target. more...

Flat crush performance test, edgewise compressive properties test and sheering properties test of both ripple structure and latticed structure sandwich composites were performed respectively. Test value of elastic modulus was obtained. Contrastive analyzing the test value and calculated value, the correctness and feasibility of equivalent mechanical model were testified. more...

The development of raft foundation design guide (RFDG) used in the high-rise building was programmed based on the secondary development language of ANSYS, such as TCL/TK, APDL and UDIL. The RFDG program provides a friendly GUI, which can be used expediently for the numerical experiment. The settlement analysis of raft foundation in the case study was carried out by RFDG. At the same time, the main technique for the secondary development of ANSYS has also been discussed in this paper. more...