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Guided by the theory of gas geology, from the perspective of economic and practical and efficient mine safety production, analyzed gas geological characteristics of The cui Jiagou coal mine, the geologic factors of affecting gas emission are analyzed, and sums up important factors of gas emission in mine field. at the same time use the regression analysis method, selecting three reasonable geological factors, including coal thickness, floor elevation of coal seam, and buried depth, make prediction of The cui Jiagou coal mine gas emission, prediction results conform to the actual situation, provide a solid security prevention and control of coal mining gas prediction subsequently.

Based on smoothed particle hydrodynamics (SPH) and FEM method, the dynamic simulation of rigid cylindric plate's sinking process on soil is studied with LS-DYNA software, and MAT 147 material model is used to describe soil's attributes. The stress distribution and flowing trend of the soil are compared at different period. The simulation results show that the SPH/FEM method is useful to analyze large deformation of soil, and our findings can give helps to the mechanical design of the components interacting with soil.

Tetrahydropalmatine in overall yield of 18% was synthesized from alkaloids in Coptids Rhizoma with the similar structure of isoquinoline by a three-step reaction of alkaloids preparation, demethylation or demethylene-dioxy, deoxidation, methylation and so on. The structure was confirmed by 1H-NMR IR and ESI-MS.

In order to strengthen the high-speed maglev trains anti-disturbance ability, the traditional linear cascade control algorithm has been improved. Firstly, the mathematical model of the joint-structure in the high-speed maglev train was established according to the dynamics and electromagnetism theory.Secondly,the advantages and disadvantages of the linear cascade control algorithm were analysed.Thirdly,the relationship between the current loop and position loop control parameters and the system performance was discussed .Finally,the nonlinear cascade control algorithm of the joint-structure in high-speed maglev train was introduced. In the algorithm,the current loop controller gain would be reduced when the positional deviation increases. At the same time, the gain of the position loop controller would be increased. The simulation results show that the suspension joint-structure gap changes caused by the failure of a single suspension point or disturbing force ,of systems with nonlinear cascade control algorithm were less than that of systems with linear cascade control algorithm. The new algorithm can improve the anti-disturbance ability of the maglev train,It can also ensure the safety and comfort of passengers.

The article established electrospun nanofibers as extraction medium to enrich and purify salidroside and detected the content changes by high performance liquid chromatography. 4 g polystyrene was dissolved in 20 mL butanone for spinning. The electrospun nanofibers was processed and loaded into solid extraction column. 3 mL sample was injected and eluted by 10 mL methanol at the speed of 2 mL/min, collecting the elution for the HPLC analysis. The results show that the relative content of solidroside increased from 24% to 55% and the extraction recovery was above 92%. The method is simple and convenient. It can replace traditional solid phase extraction to enrich solidroside.

Considering the insufficient recrystallization of austenite has an effect on deformation resistance, meanwhile, referring to the plate of controlling parameters in the hot rolling process, analysis and forecast of load parameters of rolling mill and motor per pass of its rolling process. The result shows that: The production of modern steel rolling, involved in the process, equipment problems associated with rolling load, must be taken into account in its internal organization of metal in the deformation process. The less recrystallization is, the greater the deviation of the calculated results. This should be distinguished from the traditional concept of rolling.

The glazed hollow beads thermal insulation board was made of glazed hollow beads and perlite by selecting cement and fly ash as cementitious materials, and adding appropriate amount of VAE emulsion and fibers, in the compression molding process. In this paper, the influence of different dosages of perlite replacing vitrified beads, VAE emulsion and fiber on the material properties were studied. Besides, the internal morphology of the sample was observed by scanning electron microscopy, and the action mechanism of the insulation material was explored.

Assembly accuracy has a crucial impact on the movement, load and fatigue of gear drivetrain. In this paper, a methodology on the accuracy prediction and control of complex drivetrain is presented. The proposed approach tries to simplify the assembly tolerance computation but grasping main assembly error factors in the assembly process of gear drivetrain. Jacobian -Torsor method is used in the analysis process, and results show a proper performance which indicates a potential opportunity for further deep and wide research on the 3D assembly analysis and simplification method.

The high density polyethylene (HDPE) nanocomposites were prepared by melt mixing HDPE with multi-wall carbon nanotubes (MWCNTs). In this work, the morphological, nucleation, crystallization and mechanical properties of the HDPE nanocomposites were studied by scanning electron microscopy, different scanning calorimetry, small-angle X-ray scattering and tensile testing. It was found that the tensile strength and Young’s modulus is increased by 42.4% and 116.5% at 3.wt% MWCNT loading compared to the pure HDPE. According to SEM results combined with SAXS, well-defined nanohybird shish-kebab (NHSK) entities exist in the composites, and in the shish-kebab structures fibrillous carbon nanotubes (MWCNTs) act as shish while HDPE lamellae act as kebab. The crystallization behavior, probed by DSC, suggests that MWCNTs have strong nucleation ability and shear stress plays an important role in polymer crystallization process. The mechanical properties demonstrated that the formation of the Shish-kebab structures improved the interfacial adhesion and brought obvious mechanical enhancement for the HDPE/MWCNTs nanocomposites.

The slab design, which has direct effect on the yield rate of steel and the productivity of mill in the production of medium plate, is an important neck of the medium plate production. Therefore, for the slab design of medium plate production, all of the factors which will influence yield and production efficiency should be taken into account, such as how to determine the rolling system, the broadening rate, the compression rate; the limited dimension conditions of machine; the sheared residuce and the burning loss. And then, it combines the indents and different specification of on-site finished product to design the slab of medium plate.

In this experiment, cement, fly ash, quicklime, foaming agent and foam stabilizer were used as raw materials to prepare the new foamed cement insulation material. Single-factor tests were designed to study the influence of different dosages of foaming agent, foam stabilizer and quicklime on the material properties. The optimum ratio was determined: content of fly ash was 25%, water-cement ratio was 0.37, content of foaming agent was 4.5%, content of foam stabilizer was 1.2% and content of quicklime was 1.5%. The material is tested: 3d compressive strength of the material is 1.049MPa, 3d flexural strength of the material is 0.608MPa.

In order to investigate the performance of hydraulic free piston engine (HFPE) fueled with dimethyl-ether (DME) under homogeneous charge compression ignition (HCCI) combustion, one-dimensional and three-dimensional simulation models are established by AMESIM and FIRE respectively. The simulation results show that the piston’s velocity and the displacement are dissymmetric about top dead center (TDC). The residence time of piston around TDC is quite short. DME chemical reaction kinetic mechanism is applied to three-dimensional computational fluid dynamics (CFD) model. Under equivalence ratio of 0.4, boost ratio of 1.33 and EGR ratio of 0.4, three heat release peaks appears. Oxidation of CO which contributes 38% of total energy is considered as the main reason of the third heat release peak.

Aim at technical improve of the control system in the Wind Turbine Gearbox Test Device at a factory of Yinchuan , the design plan of the control system Based on Mitsubishi FX series PLC,FX2n-4AD,FX2n-4DA,Mitsubishi FX series Ethernet adapters and King View are put forward ,lower processor was composed by FX2N series CPU module and I/O module in that control system , moreover , centralized management and real-time monitoring of collect data are carried out through the upper processor that adopts industrial computer and King View . Through the improvement device become automation, enhance safety and capacity of product development of company.

Introduced the MCU STM8S105C4’s basic framework,main function modules and corresponding technical parameters.Based on this MCU, With the crankshaft signal and camshaft signal, the throttle valve position signal, intake manifold pressure signal, and other signals for the treatment plan,the injection control and ignition control,we developed a corresponding control program flow charts and software implementation,to make sure the control of the four-cylinder gasoline engine’s operation correct. Simulation results show that,the design of the control system reach the expected goals,that makes the gasoline engine start and running steadily.

With the rapid development of automobile industry and the accelerated process of urbanization, pollution caused by automobile exhaust had become one of the major sources of urban environment and atmospheric environment pollution. According to the automobile exhaust emission characteristics in this paper, the generation mechanism of major automobile exhaust pollutants which were suspended solid particles, carbon monoxide nitrogen oxides and hydrocarbons, were described, as well as emission control measures with environmental materials.

The gas is one of the most important factors which endanger the security of the mining production. Most of serious accidents are the gas explosion accidents in coal mine. By investigating the damage situations of the gas explosion accidents and the related material, finding out why these incidents happen is an important way to prevent or reduce the gas explosion accidents. Based on the occurred gas explosion accidents, the author use the FLUENT software to simulate the process of gas explosion and get the variation law of various air current parameters is obtained in gas explosion. The explosion causes and development course are discussed. Compared with the explosion parameters collected on scene of accident, it provides comprehensive scientific basis for the accident investigation. The conclusion is helpful to adopt suitable measures to prevent the gas explosion.

Pore defect is a kind of typical non-continuous casting defect. It always brings local stress concentration and fatigue crack. The distribution charactersic of pores has greatly influence on the fatigue life. In this study, distribution characterstic of pore has described by pore to surface distance (S) and pore dispersion coefficient (r). By numerical simulation method, stress and fatigue life distribution law in the test bar have been studied under different and . Under the same load condition and pore volume fraction, the stress concentration factor (Kt) will increase and fatigue life will decrease following pore to surface distance (S) decreasing and dispersion degree (r) increasing within a limitation. The influence of pore to surface distance (S) is more obvious than the pore dispersion coefficient (r) on fatigue life of the casting.

Inverse analysis is regarded as an ideal way to achieve the mechanical parameters of rock mass using in situ measured deformation data of surrounding rock during the construction of underground engineering. Aiming at the disadvantage of high computational complexity when identifying mechanical parameters of surrounding rock by employing the inverse method based on standard support vector machine (Vapnik’s SVM), a new back analysis method based on least squares support vector machine (LS-SVM) was presented. The basic principle of the method was introduced. An example was adopted to investigate the practicality and reliability of the method, and the calculation results indicated that, compared with the inversion method based on standard SVM, the method proposed in this paper possesses higher calculation efficiency and inversion precision.

This paper mainly discussed the relation between human behave and space configuration, in order to analysis and optimize the space of urban commercial pedestrian street. In this paper, Xi'an Shu-Yuan-Men commercial pedestrian space has been chosen as a case study. Firstly, a model has been built by using space syntax on the basis of the space network, and an analysis and optimization has been offered from the technical level. Secondly, combined with space network, by recording and analysis of the human behavior, a feedback has been offered to the model according to the actual needs. At last, a final comprehensive optimization plan has been carried out. The purpose of this plan is trying to improve the shopping and leisure environment of the mall and comprehensive Land use efficiency.

This article complies with the own economic discipline of urban land and studies relevant experiences at home and abroad systematically. The article takes Chinese High-Tech Industrial Development Zone in Ankang city as an example. The authors explore that how to apply the concept of land grading in the process of urban planning, in order to guide planners to fully grasp the land qualities and rationally determine the intensity of land development.

Through the experiments of recycling bricks from building waste, the paper studies the mechanical properties and the influence factors of recycled concrete which is based on waste brick aggregates. Using the method of gravels substituted by brick aggregates with the same volume, the optimal mechanical properties can be obtained through adjusting the aggregate contents of different recycled brick sizes, the mix proportion and water consumption of recycled materials. The results of experiments show that there are some key indexes including the bibulous rate of brick aggregates, particle gradations and water consumption, and the optimal size of the brick aggregates ranges from 9.5 mm to 19 mm, and the mechanical properties of recycled concrete are slightly below the referenced concrete by lots of experiments. Therefore, building waste bricks recycled concrete are a kind of very good, sustainable and energy-saving building materials.

For hollow slab bridge, its concrete hinge joint is prone to be damaged under overload vehicles, as weakens the transverse integrity of bridge, leads to single slab bearing and threatens the safety of service. Aiming at the problem, a strengthening experiment of an actual concrete hollow slab bridge, which has experienced a destructive test with its transverse connections seriously damaged, was performed by applying external transverse prestressing to it. The strengthening design and construction technology of external prestressing were introduced. By means of truck static load test, the variation of deflections and strains of the bridge before and after strengthening under different tension force was obtained, and the influence of tension value to strengthening effect was emphatically analyzed. The test results proved the effectiveness of the strengthening method and some improvement suggestions were also presented.

Electro-slag remelting (ESR) is a kind of special metallurgy techniques to produce high quality alloy materials. The interface of electrode and slag is the energy entrance of entire system in the remelting process. Mathematical model of consumable electrode’s melting process has been built in this paper. Some valuable variation rules of droplet diameter, droplet forming time, melting rate and purification coefficient following melting current and slag bath depth have been studied through a series of simulation work. Based on the mechanism studying of the consumable electrode’s melting, some meaningful experience to optimize the technological parameters and improve material quality of electro slag ingot has been gotten.