Search

Structural and optical properties of MgZnO films were investigated by annealing in oxygen at different pressures. The crystalline quality of the annealed films improves with increasing annealing pressure. After annealing at 3.03×105Pa, the grain size became larger and oxygen content in the annealed films increased. This was attributed to the recrystallization of the films under high annealing pressure. However, a decreased oxygen content was found by annealing the films at 1.01×105or 2.05×10-3Pa. According to the defect levels and the relationship between photoluminescence spectra and annealing conditions, it was suggested that the emission peak located at 2.270 eV in photoluminescence spectra was related to interstitial oxygen (Oi) which will compensate the donor defects (Znior/and VO) and lead to the MgZnO film transforming into ap-type conduction under the annealing pressure of 3.03×105Pa.

Base on the design of seepage control, the three-dimensional non-steady saturated - unsaturated seepage finite element analysis program CNPM3D is used to establish the three-dimentional finite element seepage model of junction area during operating period. The seepage field of dam site area is studied under the different anti-seepage curtain arrangement scheme. Specifically, the seepage gradient and the seepage discharge of the panel, major material zone, foundation curtains and two sides abutment curtains are analyzed to evaluate the stability of the major district of dam area, in order to provide suggestions for choosing the seepage control standard in the next deepen design stage.The calculation results show that the panel and the impervious curtain anti-seepage effect is remarkable.Impervious curtain can greatly reduce the total seepage flow of the dam and its foundation.However the curtain deepened to 1Lu has little effect on seepage discharge. It is showed that the seepage prevention standards of 3 lu should be proposed in the deepen design stage for both security and economic benefit. The achievement and experience of this seepage prevention design should be taken into consideration for other similar projects.

With the decline of pouring temperature in the range of 750°C~675°C, solidification curve was shifted to left primitively, and then gradually turned to right. Temperature of concretion nucleation and binary eutectic reaction was increased after a reduction, whereas the time was presented dynamically, both the minimum value which were obtained at 715 °Care 23.48s and 89.24s respectively. Growth time of crystal nucleation was extended after a slight decrease, the lowest point which was appeared at 715°C is 607.25s, time of binary eutectic reaction was varied as the cubic polynomial, the minimum value that emerged at 715°C is 228.39s. Solidification curve was changed as the exponential function, cooling rates ascended initially and then dropped andante, the peak point that achieved at 715°C is 5.93°C/min. The test results of microstructure shows that the content of primary and eutectic silicon with the plate-like and needle morphology, was increased primarily and then decreased with the decline of pouring temperature, however, the changing trend of grain size was shown as opposite, the minimum value which was obtained at 715°C is 534μm. It was also found from the results of grain size that with lower pouring and binary eutectic temperature, along with higher cooling rate and nucleation temperature, grain size was refined properly.

The main dam of Banqiao reservoir consists of the concrete overflow dam and the earth dam in both sides, which are connected by concrete lateral key wall. Field observation shows that serious leakage problems exist at the connection of the overflow dam and the earth dam in right bank. According to the real size of structures, the FEM model are established to calculate and analysis the seepage field characteristics at the connection part. The potential ground water level shows that the reservoir water flowing to the downstream bypassing and passing through the lateral key wall and the anti-seepage curtain. And there exists partial seepage passage at the connection part. As the contact seepage gradient along the lateral key wall is uneven, the contact leakage at the connection part is not fully safe although the average contact seepage gradient is within the permissible range. Effective measures should be taken to solve the seepage defects at the connection part.

According to the status of vocational teaching quality evaluation, this paper will have an analysis of the AHP that is used to quantify the qualitative classroom teaching quality evaluation. It is applied to determine the weights of evaluation factors, to build a hierarchical model of teaching quality evaluation, to analyze implementation steps of AHP: construct hierarchical model-determine the weight of each factor-derived decision alternatives. Questionnaire analysis has proved that this method not only can be used to have a comprehensive evaluation of teaching quality but also to have an evaluation on the secondary index. The method is scientific, rational and has a high application value.

Aiming at the problems existed in the teaching resource management, the paper analyzes the cloud computing’s architectural pattern, and compares the existing cloud computing’s architectural platform. With the platform of Google App Engine, it proposes a kind of highly-sharing and easy-operating teaching resource management model. The model mainly includes the registration login module, educational resource management module, information exchange module and system administrator function module in the education resource cloud service platform. With the framework of ASP.NET MVC, a teaching resource management information system based on GAE is developed. The management model and system adapt to the demand of modern educational resource management with great practical value.

In order to improve the credibility of vocational teaching evaluation, the paper summarizes the traditional SEEQ evaluation model, and analyzes some existing deficiencies. Combined with the demand of current teaching evaluation, a kind of improved teaching evaluation model-VSEEQ is proposed. The model increases two new evaluation dimensions. Through the research sampling, the data is conducted the KMO and Bartlett analysis. The experiment can show that VSEEQ evaluation result can accurately reflect the practical issue existed in the teaching, thus greatly improving the credibility of teaching assessment.

A solar district heating and water heating integrated system has been designed and installed in a 5000m2 residential quarter. The integrated system uses vacuum glass tube solar collector to collect solar radiation energy, and uses water as heat medium. Solar energy provides almost 50% of the total heating energy consumption in winter. The inadequate part of energy can be provided by a steam heater which steam is provided by exhaust steam of the turbine from a power station nearby. The integrated system is operating automatically according to the solar radiation and working condition. Low-temperature floor radiation system is used as indoor heat radiator. At the same time, the system can provide 24h hot water supply. The integrated system has operated for 3 years, saves a large amount of energy, and receives good profit in both economical and environment.

For the leakage problem caused by geomembrane defect, the unstable saturated-unsaturated seepage theory and Galerkin finite element method have been adopted. So a three-dimensional finite element numerical model of an earth-rock dam with geomembrane anti-seepage system is simulated by the unstable saturated-unsaturated seepage finite element method. The influnence on seepage field for the varying degrees of geomembrane damage is analyzed, and the overall and local seepage field characteristics of the dam for geomembrane defect leakage are discussed. The results show that the numerical method provides an effective way to study the leakage problem of geomembrane defect.

Seepage failure is an important factor in causing dam-break of earth-rock dam, so the study of anti-seepage reinforcement for dilapidated reservoirs is always an important topic to earth-rock dam. Changli reservoir, since the completion, soil flow and failure by piping occur in dam slopes, the safety of downstream residents has been threatened both in life and property. Based on the comparisons of the effects of anti-seepage reinforcement schemes,the result shows that, for this clay dam, concrete cut-off wall can improve the seepage state obviously and has a higher operational stability. Thus, the concrete cut-off wall is designated as the recommended anti-seepage scheme for Changli reservoir.

Basing on field data ofQuercus glandulifera var. brevipetiolataandQuercus variabilismixed forest (MF),Quercus aliena var. acutiserrataforest (QF1) andQuercus aliena var. acutiserrataforest (QF2) at different altitudes of Baotianman Mountain, we revealed biomass C storage of tree organs for each forest, and the distribution patterns of biomass C in different forests were also indicated. We found that total biomass C of forests decrease as altitude increase. The species mixed forest store more biomass C than others. However, biomass C storages at the scale 5m×5m vary dramatically for most of the plots. Biomass C storage in organs follows the law trunk>branch>root>leaf for all the three types of forests. It is interesting that biomass C of both above̶ and belowground are MF>QF1>QF2, whereas the ratios of aboveground/belowground biomass C are QF2 > QF1 > MF. Our results indicate that both altitude and forest type are key influence factors of forest biomass C in Baotianman Mountains.

The excitation system is an important component element that influences the dynamic behavior of alternators. However, when the two-quadrant H-half bridge converter is used in the exciter field current closed-loop control system, there will be some problems of nonlinearity. To prevent the converter from working in the nonlinear area, the working conditions of linear and nonlinear area of H-half bridge converter is discussed firstly in this paper. And then it is verified by the simulation results.

AA7050and AA2024 aluminum alloys used in aviation were jointed by friction stir welding, and the tensile properties and fracture surfaces were investigated. The results show that the ultimate strength and the yield limit of welded materials can reach 90% and 75% for AA7075and AA2024 respectively, while the ultimate strength of AA7050/AA2024 FSW can reach 60.5% of AA7050 and 70.8% of AA2024, the yield limit can reach 46.2 % of AA7050 and 75.5% of AA2024. The equiaxial fine grains were found in weld nugget, the coarsen and distorted grains in the thermo-mechanically affected zone, and coarse grains in heat affected zone. The fractures occur at the advancing side between thermo-mechanically affected zone and heat affected zone. Dimples appeared on the fracture surfaces means that the fracture is ductile fracture.

This paper presents a two-quadrant H-half bridge converter used as the field current amplifier of ac exciter in the synchronous generator brushless excitation system (SGBES). Differing from the conventional amplifier, the exciter field winding can be supplied with positive and negative voltage to help increase the response speed of the excitation system. However, there will be some problems of stability when the converter is used in the current closed-loop control system. To prevent the converter from working in the unstable area, the stability of the linear area has been analyzed. Finally, it is verified by the experimental results. These can provide a valuable theoretical and practical basis for the design of parameters for the current closed-loop control system used by the converter.

Based on the actual conditions of the project and related experience, the seepage model of diversion tunnel and its surrounding rock mass was built to analyze its seepage stability. The seepage field was calculated by using finite element method (FEM) and cut-off negative pressure method. Two typical cross-sections and working conditions were chosen to evaluate the seepage stability of the surrounding rock mass. According to the results, the seepage gradient is larger when one tunnel is filled with water while the other is empty. The maximum seepage gradient is less than the allowable seepage gradient, so the surrounding rock mass of the diversion tunnel can meet the demand of seepage stability.

In order to better protect the Daqing Oilfield Sanan oil field development, make experimental analysis and field applications of Sanan's core.Through the relationship between rheology and fluid loss ,achieve JGN best dosage of the entire completion fluid system, completion rheological law and evaluated regular patten.The effect of field application is obvious, improve strength of the oil production , the skin factor and injection pressure is reduced, and made better protect the reservoir effect.

The friction and wear properties of the overbased calcium sulfonate complex grease and polyurea grease were evaluated using an Optimol SRV reciprocating friction and wear tester under the boundary lubrication conditions. The morphologies of the worn surfaces of the AISI 52100 steel discs were observed using a scanning electron microscope (SEM). In addition, the elemental compositions and chemical states of several typical elements on the worn surfaces of the AISI 52100 steel discs were examined by means of X-ray photoelectron spectroscopy (XPS). The results show that the overbased calcium sulfonate complex greases and polyurea grease have stable friction coefficients as low as 0.10-0.11. The calcium sulfonate complex grease has better wear resistance properties than polyurea grease, polyurea grease has better reducing friction properties than calcium sulfonate complex grease, According to the XPS analyses, it is considered that the formation of tribochemical films led to lower friction coefficient and high wear resistance.

To provide a theoretical guidance for the application of selective non-catalytic reduction (SNCR) in a large capacity utility boiler, numerical study of SNCR process in a 600 MW utility boiler was performed based on computational fluid dynamics (CFD) code Fluent. Good agreement of the calculation results with the industrial test data confirms the reliability of the calculation model. It is found that the NO removal efficiency is low and NH3-slip is high, because the injected reducing agent could not mix with the flue gas adequately, and the furnace temperature is not uniform in utility boiler with large furnace size. Aiming at this problem, the commissioning scheme for reducing agent injection system was optimized, and CO was added together with the reducing agent. As a result, NO removal efficiency increases from 19% to 27%, and NH3-slip decreases from 59 ppm to 13 ppm.

Acid sludge is one of the major oil field acidification increased production ineffective. Therefore, the acid sludge formation of influencing factors on improving acidification effect is of great importance. The Suizhong 36-1 oilfield is selected as the research object , a more in-depth study of the acid sludge formed in the acidification process influencing factors . The results show that: With the increase of crude oil in the colloid and asphaltene content , the amount of oleic acid mixture to form acid sludge also increases . Strong acid ionizing out of the higher concentration of H+ , the faster of the speed, the forming acid slag trend is obvious. The residual acid pH value increased , the amount of acid sludge also will continue to rise.

In this paper,we used the heavy oil of Du 84,53-55 well in Liaohe oil field,analyzed of the impact factors of the heavy oil emulsion viscosity.When the droplet size of the emulsion is reduced,the viscosity of the heavy oil emulsion increases,and the non-Newtonian obvious.Heavy oil emulsions exhibit Newtonian fluid properties at low shear rate,exhibits shear-thinning properties in the heavy oil emulsion under high shear rate.Heavy oil emulsion viscosity decreases with the increasing concentration of viscosity reducer,when the viscosity reducer concentration of more than 0.25%,heavy oil emulsion viscosity declines slowed.

According to the actual engineering conditions of Haokou RCC Gravity Dam, the 3-D FEM model of the typical overflow dam section and its foundation is set up. Using the response spectrum method, the responses of earthquake acceleration, displacement and stress of the dam and their distribution laws were studied under the seismic loading, and the anti-sliding stability of dam is also analyzed. The calculation results show that under the design earthquake condition, the maximum principle stress response of dam body is 2.26MPa, which appears at the dam heel. The safety factor of stability against sliding on the face of the dam foundation is 1.43 and the stability against deep sliding is 3.2. So this dam section can meet the strength and stability requirements of standard, its earthquake-resistant safety could meet the requirements of standard.

Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.

This paper describes study of temperature variation in the gelling and hardening, thermal baking and pouring stage of foaming gypsum mold. The temperature difference curve in the gelling and hardening process shows an rapid decline, tending to the placid downward eventually after a clipping rise. During the thermal baking stage, owing to the low heat conduction coefficient of the foaming gypsum mold, the actual temperature of each thermocouple lags behind the craft temperature, lag degree increases gradually with the extension of baking temperature and holding time. At the initial period of pouring process for molten aluminum, the temperature of center position in the mold increases fast by absorbing lots of heat in the solidification process, whereas, slower temperature rising curve occurs in the edge and intersection position. Coupled with the ongoing of air convection heat transfer, resulting in a continuous falling of temperature, therefore the temperature difference curve of each point inside the mold shows a successive upward trend with the solidification process of molten aluminum alloy.

A cationic Gemini surfactant ethane-1, 2-bis (Cetyl dimethyl brominated ammonium), denoted 16-2-16 was synthesized from ethane and Hexadecyl dimethyl amine. The properties of the product were characterized, and the physical and chemical properties were determined. The results showed that the synthetic product was the target product, and its surface tension was 3.4×10-4N/m, and the CMC was 2.2×10-4mol/L at 25°C. At the same time, its synergistic effect with common surfactants was studied; the results showed that the synthetic product had good synergic effect.

A modified phenol-formaldehyde (PF) resin was synthesized under alkaline condition in varying proportion of borax up to 21% (w/w). All the prepared resin were characterized by free phenol content, free formaldehyde content as well as hydroxymethyl content. It was proved by Fourier transform infrared spectrometer (FTIR) that B-O bond had been successfully introduced into the structure of PF resin. Thermo gravimetric analyzer (TGA) and different scanning calorimetry (DSC) were used to characterize the thermodynamic characteristics of the PF resin. The result showed that when the mass fraction of borax was 9wt.% of PF resin, the heat resistance was the best and the curing temperature of the modified PF resin was higher than that of the unmodified PF resin.

MFR high temperature profile control agent consisted of 6.5% wood Fortunately sulfonic acid calcium (Ca-LS) and 6.5% crosslinker modified furfural resin (MFR),and the gel solution formed a stable performance gel in the 150~300°C.The higher the temperature, the shorter the gelation time; and the longer the heating time, the higher the gel strength. The gel is very stable at 300°C, and is well in acid and salt resistance. The core experiments showed that the blocking agent's blockage ratio is more than 99% ; the units of the breakthrough pressure was greater than 100 kPa / cm,which the gel solution is a good performance of high-temperature profile control agent.

The main problem dehydration system of XinMu Oil Field at present is high dehydration temperatures,high the amount of demulsifier, increase output moisture content year by year and more and more frequent fluctuations.Through the reform to establish a dehydration subsystems,and composite demulsifier alone to deal with special oil to eliminate the influence of special crude oil to dehydration system.Filter out Daqing produced 169＃ demulsifier 150mg·L-1, when add oxalic acid 200mg·L-1 and fungicide 100mg·L-1 the demulsifier of good dehydration effect.After processing crude oil water content of less than 5%,sewage oil content of less than 20mg·L-1, which has solved the dehydration problems of troubled XinMu for many years.

In the context of “Plan for Educating and Training Outstanding Engineers (PETOE)”, which was put forward by the Chinese Education Ministry, we would make great efforts to explore a new training model of practical teaching that face to the “Outstanding Plan”. The new training model will aim at enhancing the students’ practical ability in engineering, innovation ability, and their employment competitiveness. The new training model should be established according to the practical teaching situation of the present higher engineering education and combine the factual condition of our school, what’s more, it also based on the implementation of the “cooperation of colleges and enterprises, combination of work and study” training model of the CDIO (Conceive, Design, Implement and Operate) engineering education.

In view of the actual application of the status quo of the current digital campus universities, a unified campus authentication systems and solutions for the overall framework was proposed based on the introduction of Kerberos technology and LDAP protocol, in order to improve the utilization and security of campus resources.

The formaldehyde emission test of MDF decorated with a paper sheet impregnated thermosetting resin was done under the simulated indoor conditions. The results showed that formaldehyde emission decreases after being placed under the condition of high temperature and relative humidity. In addition, the formaldehyde emission of medium density fiberboard with paper impregnated thermosetting resins (MDFPs) increases along with the increase of furniture-bearing ratio.

Simulation of the common application environment of furniture were carried out, effects of different processing methods, storage time and airtight time were investigated. The results showed that the longer storage time or shorter airtight time was, the lower formaldehyde emission was. While the shedding of edge banding and metal connecting parts would increase the formaldehyde emission.

Physical properties of thermal regulating polyacrylonitrile (PAN) fibers prepared at different concentration of coagulation bath were tested to investigate influences of coagulation bath on properties of the fibers. Results indicated that linear density of the fibers increased, breaking strength, thermal shrinkage and boil water shrinkage decreased while elongation first increased and then decreased with the increasing of mass fraction of sodium thiocyanate (NaSCN) in coagulation bath. The optimum NaSCN concentration in coagulation bath should be 10%. Fibers prepared under the above NaSCN concentration showed good mechanical and thermal properties, and the breaking strength was 1.35 cN/dtex, the enthalpy was 26.0 J/g and the thermal efficiency was 78.4%.

Reliability-based design optimization (RBDO) evaluates variation of output induced by uncertainties of design variables and results in an optimal design while satisfying the reliability requirements. However, its use in practical applications is hindered by the huge computational cost during the evaluation of structure reliability. In this paper, the reliability index based decoupling method is developed to improve the efficiency of probabilistic optimization. The reliability index is used to calculate the shifting vector in the decoupling process, due to its efficiency in evaluating violated probabilistic constraints. The computation capability of the proposed method is demonstrated using two examples, which are widely used to test RBDO methods. The comparison results show that the proposed method has the same accuracy as the existing methods, and it is also very efficient.

For probabilistic design problems with implicit limit state functions encountered in practical application, it is difficult to perform reliability analysis due to the expensive computational cost. In this paper, a new reliability analysis method which applies support vector machine classification(SVM-C) and adaptive sampling strategy is proposed to improve the efficiency. The SVM-C constructs a model defining the boundary of failure regions which classifies samples as safe or failed using SVM-C, then this model is used to replace the true limit state function,thus reducing the computational cost. The adaptive sampling strategy is applied to select samples along the constraint boundaries. It can also improves the efficiency of the proposed method. In the end, a probability analysis example is presented to prove the feasible and efficient of the proposed method.

This paper suggests a design space exploration method using Artificial Neural Networks and metamodeling to systematically reduce the design space to a relatively small region. This method consists of three major steps. Firstly, self-organizing maps is employed to analyze design variables and objective function(s) with the original samples as preliminary reduction optimization of the initial large design space. Successively, resampling within the preliminary reduction space, clustering sample points using the fuzzy c-means clustering method with the given number of cluster, and choosing the most attractive cluster to construct kriging model and identify the design optimum within the reduced design space in the last step. The accuracy and validity of proposed methodology is proved by a heat exchanger design problem. It is found that the proposed method can intuitively capture promising design regions in which it is efficient to acquire the global or near-global desigm optimum.

Nowadays, computer-based engineering design is becoming widely used in the design of products. In the field of engineering, CAD model, FEM method and surrogate model are used to reduce the time and computational cost comparing with the traditional engineering design. But when facing with computationally expensive tasks, such design method mentioned above seems unable to deal with such tasks. In that case, surrogate model is gradually used and shows great potential in dealing with the computationally complex tasks. Although computing power and speed are rapidly growing, the use of the computer simulation analysis is limited in doing engineering design and some other analysis such as reliability analysis for complex product, so that it limits the use of metamodeling techniques. In that case, we use space-filling DOE sample method to support the construction of surrogate model. In this paper, we consider both Hammersley sequences and SVM as sampling method and surrogate model to construct the simulation design model, aiming at reduce computational costs. SVR achieves more accuracy and shows great potential in application in the design of complex and computationally expensive tasks.

In order to provide necessary basis for utilization of Anthocephalus chinensis, its chemical composition was explored in this paper. The results as follow: Cold water extractive is 3.18%. Hot water extractive is 4.58%. 1% sodium hydroxide extractive is 18.78%. Alcohol-benzene extractive is 2.73%. Content of cellulose is 44.09%. Content of acid-insoluble lignin is 23.31%.Content of holocellulose is 74.72%. Content of hemicellulose is 30.67%. pH value of wood is 5.31. Through comparing with other species, the results suggested that A. chinensis is ideal material for wood-based panel, interior decoration and packaging.

Fiber and vessel morphology and the radial variation patterns of fast-growing Toona ciliata were studied in this paper. The results showed that the average of cell length, tangential diameter, double wall thickness, length-width ratio, wall thickness-diameter ratio of fiber were 1038.00μm,17.43μm,4.03μm,34.13,0.25 respectively, which of vessel were 313.61μm,123.63μm,6.18μm,1.36,0.05 respectively. The radial variation patterns vary between different characteristics.

Low formaldehyde emission and high bonding strength were two basic criterions of a good urea-formaldehyde resin adhesive (UFRA). In our study, melamine modified methylolurea solution (MUS), was synthesized and used as modifier for UFRA. The bonding strength and formaldehyde emission of urea-formaldehyde resin adhesives(UFRA) were influenced by some factors such as F/U molar ratio of the main resin, F/U molar ratio of modifier, melamine content, mixing ratio of main resin with modifier, which were investigated by a series of single-factor experiments. The results showed that the best adhesive bonding strength of UFRA was 0.93MPa and the lowest formaldehyde emission was 0.43mg / L, when F/U molar ratio of the main resin was 1.5, F/U molar ratio of the MUS was 0.5, the mass fraction of melamine addition level was 5wt.% of MUS, and the mixing mass ratio of methylolurea solution (MUS) to the main UF resin was 20:80.

In this paper we focus on parameter estimation of the futures price processes with a Ornstein-Uhlenbeck process and jump-diffusions. We use the generalized moment method to derive the OU process. Afterwards, we fit a jump diffusions model to Copper prices from Shanghai Copper futures market.

In this paper, anatomical characters and tissue proportion of fast-growing Toona ciliata samples from Guangzhou was investigated assisted with the light microscope and image analysis system based on the principle of stereology. Qualitative and quantitative data were presented for purposes of identification. Results showed that fast growing T. ciliata was coarse texture with wide growth ring of 3~5cm.The ray proportion was 12.12%-25.56%, the mean value was 17.98%, increasing with time-dependent relevance. The vessel-elements proportion was 6.37%-10.00%, the mean value was 7.40%, increasing then declining and finally increasing. The fiber and other tissue proportion was 67.06%-79.92%, the mean value was 74.62%, declining by year.

The intent of this survey is to provide general design and operating considerations for the safe and dependable operation of remotely operated hot cell equipment. Hot cell is an isolated shielded room that provides a controlled environment for containing highly radioactive and contaminated material and equipment. Operations within the hot cell are accomplished using master-slave manipulators and overhead crane or electro-mechanical manipulator systems.

This paper describes the cast structure study of A357 aluminum alloy stress frame casting under consecutive solidification and simultaneous solidification by test and numerical simulation methods, with the conclusions of tensile tests by using of SEM and EDS analysis, the mechanical properties and fracture morphology were observed both under the cast and T6 heat-treatment state. Intergranular fracture cracks were observed to be the main failure mode in the casting state condition, cracks originated from the tissue defects and continued to proliferate until the tensile specimens were ruptured. Simultaneous solidification can decrease the casting shrinkage and micro-cavity and improve the mechanical properties of the castings. Dimple fracture was the dominated failure mode after T6 heat treatment state, the distribution of some intergranular cracks staggered with dimple fracture can surveyed under the fractography analysis. The superiority of simultaneous solidification was demonstrated by the numerical simulation of China casting CAE.

The pyrene/pyrrole copolymer (Pn/Py copolymer) has been sucessfully synthesized by the facile chemically oxidative copolymerization. UV-vis and FT-IR spectra are used to investigate the molecular structure of the copolymer. The results show that pyrene and pyrrole units in the copolymer chain are interconnected via α, α-coupling to form a linear structure. At the same concentration, the copolymer solution exhibits the strongest green fluorescence with a maximum emission at 503 nm and a large stokes shift of about 113 nm by fluorescence spectrometer. The excellent fluorescence of Pn/Py copolymer may be due to its better planar molecular structure and higher large π-conjugation, that is confirmed by UV-vis spectra and molecular simulation.

This chemical synthesis-based pharmaceutical wastewater is treated by the process of hybrid hydrolysis acidification technique (HHAT) with anaerobic-low DO condition and the hybrid aerobic bio-technology consisted of alternate-flow biological reactor (ABR) and two-way-flow biological aerated filter (TBAF). The micro aerobic technology was employed in the HHAT and showed its advantages in refractory organic wastewater treatment. The largest plant in pharmaceutical wastewater treatment at home was built. The practice shows that the organics can be greatly removed and the effluent can reach the First Grade Discharge Standard which can be reclaimed with advanced treatment. The performance indicates that the combined bio-technologies are stable in pharmaceutical wastewater treatment.

In this paper, we introduced the method of preparing cationic copolymer clay stabilizer PDA and something about its laboratory study. Dimethyl diallyl ammonium chloride (DMDAAC) and acrylamide (AM) were the reaction materials, and potassium persulfate was the initiating agent, which was used to synthesize the cationic copolymer clay stabilizer PDA. Through laboratory experiments, the performance of clay stabilizer PDA was evaluated, and the results were as follows: the anti-swelling performance of PDA was better than that of KCl solution and another cationic copolymer clay stabilizer PTE. The swelling ratio of 1.0% PDA clay stabilizer was only 15.3% and anti-swelling ratio was more than 72.0%. Under the temperature of 25°C to 150°C, the anti-swelling performance was still stable. Furthermore, clay stabilizer PDA performed well in resisting salt and calcium at normal temperature, and the average damage ratio of natural cores was less than 17.5%.

Expound the report implementation of user-defined management information system (MIS) from the parts of system design, functional modules and system implementation. Meet the requirements that the report in user-defined MIS should be dynamic, flexible and user defined by using technologies of dynamic arrays and DataList in Visual Studio.net.

For the purpse of meeting the needs of modern automobile parts and equipment test, a modular reconfigurable testing system for automobile parts and equipment was carried out. In the testing system, industrial computer as host computer performs human computer interaction, and the client computer is extended based on FPGA(Field Programmable Gate Array). FPGA excutes real-time task that can be configured according to mission requirements. The procedure of modular testing system which was designed with the Microsoft Visual C++ 6.0 is divided into human computer interaction and driver layer. The result showed that the system can be used for rapid design of auto parts and equipment testing system. The result of the present work implied that the reconfigurable testing system has good flexibility and expansibility.

Thermal conductivity prediction models of cement-based materials are inconsistent. In order to get the correct model, parallel hot wire method is used to measure the thermal conductivity of aggregate, cement paste, mortar and cement-based materials. Theoretical analysis values and experimental values of thermal conductivity of cement-based materials are compared to get the correct series-parallel model of the material. Through further research, the test results that the influence of aggregate location and aggregate size on the thermal conductivity of cement-based materials can be ignored in the case of the same aggregate content.

3-dof wire-driven parallel mechanism is studied in this research. The kinematic analysis of this wire-driven parallel mechanism is given according to analytical method. The method for spline function is proposed to generate a continuous, smooth and noiseless trajectory of the wire. The simulation results, based on simulink, verify the rationality of this trajectory planning algorithm