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CaSO4·0.5H2O whiskers were successfully synthesized by hydrothermal process, in which phosphogypsum (PG) was employed as precursors. The effect of the hexadecyltrimethylammonium bromide (CTAB) on the formation of phosphogypsum-based CaSO4·0.5H2O whiskers was investigated in details. Results indicated that the average diameter and length of as-prepared CaSO4·0.5H2O whiskers with rough surface were about 0.15-2.5μm and 10-50 μm, respectively. The added CTAB templates would effectively guided the selective growth of CaSO4·0.5H2O particles which led to formation of whiskers with high aspect ratios.

In this paper, we have synthesized new functionalized Al2O3 nanoparticles successfully via reaction, which was grafted polyurethane onto the surface of nanoparticles dispersed in n-butyl acetate. The structure, surface properties, and thermal stability of the functionalized Al2O3 nanoparticles were characterized by means of by FT-IR, TGA and SEM. The results showed that the surface of Al2O3 nanoparticles has been grafted with polyurethane (PU). Furthermore, Al2O3 nanoparticles was dispersed evenly in the organic solvent, which can show a long suspension stability near to 6 months without precipitation, indicating that this product is very useful to prepare stabilized coating nanocomposites.

A new fatigue life simulation analysis method for spot weld joints is proposed which considers the fatigue crack propagation from the point of fracture mechanics. The traditional fatigue simulation analysis methods for spot weld joints are mainly LBF method based on force and LMS method based on stress, while there exist some issues such as the prediction accuracy is not high, modeling and computational efficiency is low. A modular spot weld model is adopted in this paper, the node forces and moments around the spot weld are extracted through the finite element analysis, then a average stress intensity factor through the crack propagation path is calculated as the evaluation parameter of fatigue life. Shear fatigue test is designed for spot weld joints with two high strength steel materials (HSLA340GI and DP600GI) and four different thicknesses, then double logarithmic regression analysis is implemented between the average stress intensity factor and the fatigue life data of spot weld joints, then a matching curve is obtained as the fatigue life prediction curve for spot welds. Comparative analysis of prediction accuracy is implemented for these three methods, the results show that the prediction accuracy of fatigue simulation method for spot weld joints in this paper is higher than traditional LBF and LMS methods.

For the problem of serial robot structure error, method of relative position correction was researched. An adaptive filtering correction method based on robot joint position feedback was proposed. The method built a robot joint adaptive filtering corrector (AFC) to correct robot joint feedback. The real spatial position of robot end-effector can be got through the forward kinematics computation with the corrected joint feedback. Thus, the robot structure error is corrected. Weights matrices of AFC were trained with relative positions between calibration points on the standard calibration module. The proposed method of relative positions correction provides a new way for serial robot structure error correction, which does not directly modify the robot kinematics design parameters, dose not need measuring equipment, and can be applied in field. The simulation results got with LabVIEW robot module show that the corrected trajectory of robot end-effector is more approaching to its true trajectory than before, which means the robot structure error is effectively corrected.Keywords: Correction; Relative position; Serial robot; Kinematics

With the development of national fitness activities, stadiums with all kinds of standards are established across the country. The functions of illumination and refrigeration inside stadiums have applied electricity. In order to save the consumption of energy, keep the sustainable development of society, as well as reinforce the consciousness of environmental protection, the thesis designs a set of novel light guided automatic lighting system of solar energy. The system realizes indoor illumination with controlling system. In the daytime, the system uses optical materials with automatic following lighting for indoor illumination, while uses stored energy of storage battery provided by daytime solar panel for LED illumination. The solar cell also provides energy for daytime automatic following lighting device. This device can take full advantage of solar energy to deal with the problem of energy waste, as well as proposes a new idea for energy conservation and emission reduction for stadiums.

With the continuous development of large-scale, high-speed ship, considering economy and security of the ship, propeller design and performance research are of importance. In this paper, the best propeller is obtained by using the propeller design software HydroComp PropExpert and HydroComp PropCAD. Propeller geometry model is generated by Solidworks. Applying computational fluid dynamics method (CFD), we can take numerical simulation for the flow around the propeller. Finally, with the help of the software ANSYS, hydrodynamic performance of the design propeller can be forecasted. The results from the calculation and analysis can provide some reference for engineering practical problems and theoretical study.

Through the analysis of processing 3D point cloud data obtained by laser radar and establishment of the point cloud model to calculate the volume and displacement to monitor the particular scene in accordance with the detection strategy of the dangerous situation, This article wants to develop a set of all-weather, real-time early monitor system, in order to timely risk information publish, reduce the losses caused by disasters. The system uses a modular design approach, which is divided into the information collection module, the information processing module, the analysis of early warning modules and information transmission module. The paper details the system design, and application in the design and implementation of technology and point cloud data processing algorithm. The system use serial programming techniques for laser radar data and control PTZ, and multi-threading technology to improve the efficiency of the serial communication and resolve the problem of multi-serial real-time data collection.

Fatigue crack propagation threshold is an important property for the structures with long life, such as nuclear turbine welded rotor. The fatigue crack propagation thresholds of multi-layer, multi-pass SAW weld metal of nuclear turbine rotor simulate are tested. But a big dispersion is found among test values, even at the same stress ratio . The dispersion of critical points between stable propagation zone and near-threshold zone is confirmed as an important reason. After the observation of microstructures around the critical points by backward inference method in different specimens, a good correspondence between the sizes of prior austenite grains and the maximum sizes of monotonic plastic zone at the crack tip is established. The inhomogeneous microstructures in SAW weld metal are the basic cause to dispersion of fatigue crack propagation thresholds at the same stress ratio.

The cooperative vehicle infrastructure system (CVIS) is currently the hot spot in the field of world transportation, but also the important development direction of the intelligent system of traffic in the future. This article combinations the present status of development of the cooperative vehicle infrastructure system (CVIS) at home and abroad, faces the application and development needs of the cooperative vehicle infrastructure system (CVIS), analyzes the data flow of the cooperative vehicle infrastructure system, and proposes a design of the cooperative vehicle infrastructure system (CVIS) based on the internet of vehicle, thus provides the basic reference for the design and development staff.

With the extensive application of electronic, computer and electromechanical integration technology in the automobile industry, the concept and mode of detecting and repairing to auto have a fundamental shift. So the corresponding professional teaching methods should be improved. In view of the present situation that automobile teaching equipment is not suitable for the new situation, we study and design the checking and testing car for whole circuit. The car based on a typical vehicle has a further development. And it has a new design, compact structure and convenient operating way, which also has the functions such as dynamic demonstrating all electrical appliances, circuit connection, fault setting, dynamic detection and ECU code query, reading out the fault code and data flow, waveform analysis and actuator testing by using computer diagnosis instrument. So it can help greatly to improve students’ technical skills and work ability.

Titanium alloy tube has been widely used in various industries due to its good corrosion resistance, small proportion and high intensity. In this research, TA2 Titanium Tube has been deeply processed under different rolling speeds and heat treatment. Through the experiments the following conclusions have been made: rolling speed has little effect on the TA2 tube properties; the tube with 485°C by 3min induction heat treatment after rolling could obtain 534MPa tensile strength, 406MPa yield strength and 30% elongation. As heat temperature increasing, the microstructure of the TA2 tube transfers from fiber to equiaxial structure; the surface stress of the tube is tensile stress and heat treatment can reduce the surface residual stress.

In marine organisms the carbon sink function of shellfish moves in circles. It not only has a great influence on the marine environment, also has the very important significance for the construction of marine ranching to realize the benefits of recycling economy. If the carbon consumption exceeds marine soil and Photosynthesis Carbon input, the marine environment will be subject to different degrees damage, and affect the marine farming production process. Based on this, this paper analyses and studies the shellfish and algae carbon sink function. The first part of this paper introduces shellfish and algae carbon sink regulation function, gives the schematic diagram of carbon cycle, and establishes a column chart through using the preliminary statistical data. The second part establishes the shellfish and algae carbon sink ecological economic system mathematical model in the construction of marine ranching, and gives the adjustment function diagram of ecosystems two coordination function. The third part uses the professional statistical analysis software SAS to draw the shellfish and algae carbon curve of marine ranching construction, which provides theoretical reference for considering the carbon sink function of marine ranching construction.

GdVO4 was synthesized by solid state reaction at high temperature and characterized by XRD, UVvisible DRS, BET and SEM. XRD analysis of GdVO4 showed its structure was of tetragonal type. When GdVO4 was loaded with 0.3 wt% Pt, it showed the better photocatalytic activity for water splitting under simulated solar irradiation, and the amounts of the produced hydrogen in pure water were about 9.33 μmol under the irradiation of simulated solar for 6 h. Furthermore, photodegradation of Rhodamine B (Rh B ) on the samples were investigated under simulated solar irradiation.

This paper presented a biogas-solar hybrid system and investigated the feasibility of using biogas to increase the enthalpy of parabolic trough collectors steam so as to increase the cycle efficiency and power production. High temperature anaerobic digestion (AD) was adopted to produce biogas by using corn straw, manure and sewage. Biogas fraction and energy-to-electricity efficiency were used to evaluate the biogas contribution to the electricity generation and the energy utilization efficiency based on off-design performance analysis respectively. A comprehensive levelized electricity cost (LEC) and life cycle assessment (LCA) for the hybrid system power production were performed. The simulation calculation results show that biogas utilization plays an important role in the decrease in systemic LEC and greenhouse gas emissions. Improvement is achieved in both of generation cost and greenhouse emissions for biogas-solar hybrid plant compared to solar-only plant.

Taking the AODV protocol as an example, the attack characteristics of different types of black holes are analyzed. Then, an attack model of black hole is established. Finally, the effects of black hole attacks to network performance are analyzed by simulations in different types and intensities. The simulation results show that this model can accurately simulate the impact of black hole attack on network performance and can provide reference and corresponding simulation environment for the security research of Ad Hoc network.

The intermittency and volatility of wind power has brought adverse effects on the large-scale wind power integration. The hybrid energy storage system coordinated with wind farms has been set up in order to reduce the volatility of output power of wind farms strongly. The allocation plan between high-frequency and low-frequency wind power can be determined with low-pass filter method in order to determine the restraining target of different energy storage devices. According to the capacity and the state of charge of the batteries and super capacitor, the power reference values can be corrected with fuzzy adaptive control method and exceeded power deviation of the target would be allocated between the two kinds of energy storage devices. The reasonableness of the proposed models is verified by case study results.

This paper investigated the effects of mesophilic temperature (35°C) and thermophilic temperature (55°C) on the hydrolysis and acidification phase in the process of organic wastes anaerobic digestion. Here, the organic wastes refer to the mixture of corn straw and pig manure in this paper. The results show that pH value is negatively correlated with volatile fatty acids (VFAs) concentration, throughout the process both the VFAs concentration and its maximum of mesophilic temperature are bigger than that of thermophilic temperature, but it takes longer time to reach the maximum; the total solids (TS) removal rate of thermophilic temperature is 31.85% and the mesophilic temperature is 27.33%, but it needs to consume more energy to maintain a high temperature state. The above results suggest that the mesophilic is more advantageous than thermophilic temperature in the treatment of corn straw and pig manure co-digestion, but the post-disinfection treatment is needed.

To explore the influence of the water vapor cooling conditions on grinding temperature field of titanium alloy TC4 material, ANSYS simulation and test methods are adopted in this paper. Simulation and experimental studies show that: water vapor as coolant can reduce the surface temperature of the workpiece quickly by changing the wheel speed, workpiece speed and cutting depth; Water vapor cooling can control the grinding zone temperature below 400 °C on certain conditions, and compared with dry grinding it can reduce more than 50%; The grinding zone temperature can significantly be reduced by optimizing the grinding process parameters and improving the quality of the machined surface.

Ultra High Frequency (UHF) band is increasingly widely used in military maritime satellite communications due to its good communication performance. When the electromagnetic wave reaches the sea surface, it is reflected. The reflected wave and direct wave enter the receiver in the form of a superimposed vector, which will inevitably produces multipath fading at the receiving end. This paper followed the general principles of modeling in multipath effects, and the UHF band multipath effects of sea surface were studied. The judgment basis was obtained which determines whether the specula reflected wave dominates in the reflected wave based on Rayleigh criterion, and then the reflection coefficient of sea surface were calculated. Finally, the power attenuation of reflected wave relative to direct wave for different wind speeds were simulated and analyzed.

The objective of this study is to analyze the crash frequency by collision type at freeway diverge areas. Three major collision types were identified in this study including rear-end, sideswipe and angle collisions. We compared the crash counts and crash rates by collision type between exit ramp. The data analysis results show that exit ramps with lane-balance design have lower crash frequency and crash rate of rear-end collisions than those not lane-balanced.

Wherever possible, we have adopted the newest modern technology. The Au-Si binary alloy sintered chips are silicon or silicon carbide power devices. The sintered temperature is 380 to 390 °C. Using micro-infrared thermal image instrument, compares the microwave transient infrared thermal image test results of sample devices which chips welded process under two different process condition. Measured results show that the thermal resistance after chip welded process optimized is twenty percent smaller than before. It describes the importance of controlling the chip welded process parameters during assembly.

To meet the special needs of the bolting and shotcreting work environment of coal mine, a new pneumatic spring-piston mechanism was designed. The derivation process of the pressure loss equation was described based on S.Morinaga formula. The concrete pumping machanism kinetic model was constructed and analysed using Lagranges Equation. The work of this paper lays a theoretical foundation for optimization design of wet spraying machine system.

Combined wireless sensor network technology (WSN) and infrared control technology this paper designs an intelligent control system for split air conditioner (ACSS). The system adopts the SimpliciTI protocol and a highly integrated chipset, CC1110, as wireless sensing node, which it has high efficiency and lower power. The intelligent remote control unit of the system is capable of signal conversion, wireless communication as well as infrared control ability. In order to suit different air conditioners, the system establishes a control code library by learning a variety of air-conditioning infrared control signals. The control parameters optimized by the system server are transmitted to the intelligent terminal and then fires the infrared control signal to the air conditioner. Therefore, the system achieves the purpose of the remote intelligent controlling.

By using the self-developed meso shear test equipment for coal or rock containing gas, non-restrictive direct shear tests under the gas pressure of 0 MPa, 0.5 MPa, 1.0 MPa and 2.0 MPa were carried out. Based on the shear stress-shear stain curves and the meso-evolution laws of the shear fracture cracks, Fracture characteristics of the raw coal containing gas under shear loading was analyzed. The results show that: i) the gas pressure can hasten the growth rate of the fractural crack in raw coal containing gas, and accelerate its shear fracture process; ii) the shear fracture process of the raw coal containing gas experiences five stages; iii) the shear breaking process of coal results in two cracks: shear crack and tensile crack, and the cracks first appeared in the shear plane at both ends, then extension to the central until shear fracture surface formed.

We put forward a new specialty blasting method to solve drill-jamming based on stress concentration and stress wave theory. Drill-jamming accident of banji was successfully solved at the early 2006 through this method first: for this drill-jamming, study drilling tools and location of drill-jamming to find the weak position (Fig. 1); produce impact loading and form stress concentration (Fig. 3) at weak position by place well-designed explosive package at special position. Through many times controllable safe explosions and repeatedly impact loading, accurate fracture, separate sinker bar and the above parts from drill bit, this part raised up successfully (Fig. 7). The rest would be taken out after second reaming.

In order to resolver the question of transmission reverse gear noise, this paper construct virtual transmission model with MASTA soft and analyze NVH ,computed transmission system frequency and gear mesh frequency, finally, find system’ resonation point and corresponding engine speed, this result is accordant to test one, finally, paper draw a conclusion that the noise is caused by resonation at some engine speed.

Scanning electron microscopy (SEM), X-ray power diffraction (XRD) and Zeta potential () analyzer were used to investigate the changes of morphology, species, crystal quantity, , and aggregation state of urinary crystallites of calcium oxalate (CaOxa) stone formers before and after taking drug potassium citrate (K3cit). Before taking K3cit the edges and corners of urinary crystallite were sharp and aggregated significantly, the main components were uric acid, calcium oxalate monohydrate (COM) and phosphate, etc. While after taking K3cit for one week, some of urinary crystallites became blunt, the aggregated crystallites and the species of crystallites were obviously reduced, the amount of uric acid was reduced, but the percentage of calcium oxalate dihydrate (COD) and the absolute value of increased. Especially crystal depressions emerged at the surface of some crystallites, which was the direct proof of K3cit dissolving CaOxastones in vivo. From the point of coordination between K3cit and Ca2+, the increase of pH and citric acid concentration excreted in urine after taking K3cit, the mechanism of how K3cit inhibit the formation of COM stones was discussed.

Cleanliness of steels is one of the major factors influencing the final product quality. This paper introduced industrial practice of producing clean steel by EAF-LF-VD-Billet casting process. The cleanliness of 55SiMnMo steel during the whole producing process was analyzed by methods of sampling systematically and comprehensive analysis including total oxygen and nitrogen content analysis, optical microscope observation and SEM+EDS. The factors affecting the steel cleanliness were discussed. Some measures to improve steel cleanliness were proposed.

We use the nonstandard finite difference (NSFD) method to construct discrete models of the reaction diffusion equation. A nonstandard finite difference scheme for the reaction-diffusion equation is given. We demonstrated that the space denominator function can be based on the use of a transformation from the simple expression (Δx)2to an 4C(sin[(1/C)1/2((Δx)/2)])2.which is clearly valid for sufficiently small Δx. Another important class for which this method keeps the equation solutions are positivity and can be applied is those PDE's without advection term.

Coal containing gas is porous material. In this paper, by using the self-developed meso shear test equipment for coal or rock containing gas, shear crack propagation process of coal under different gas pressure conditions was studied, and shear performance of coal containing gas under different gas pressure was also researched. The results show that the gas pressure can hasten the crack growth rate of shear fracture surface, reduce the shear strength of coal containing gas, and accelerate its shear failure fracture process. The shear breaking process of coal results in two cracks: shear crack and tensile crack, and the cracks first appeared in the shear plane at both ends, then extension to the central until shear fracture surface formed.

When ship navigating in the winding channel, a transverse drifting distance will be produced due to some dynamic factors, such as wind and current; meanwhile, the rudder must be frequently used to alter course so that the vessel can be navigated safely in the channel. Because of the above reasons, the width of the water area that is need to carry out altering course maneuvering is greater than that is needed to navigate straightly. Giving full consideration of drifting due to wind and current, the value of widened channel when altering course in winding channel, this paper puts forward the mathematical model for width in winding channel.

The arm system is the central part in the design of a portable crane. The purpose of this program is to assure that the load moves approximately along the path of the horizontal direction in the process of luffing, through the optimization of the bars’ length of the arm system. Using vectors in the mathematical model, we figured out the coordinates of the bottom point of the truck-beam according to the geometric relationships of the four-bar linkage. With the appliance of proper algorithm and the idea of visualization, we calculated the reasonable length of the bars in MATLAB and transformed the results into software ultimately. The design is suitable for different types of portable cranes, and the software is very convenient and can be used in engineering.

This paper focuses on the static and dynamic characteristics of a high speed CNC lathe feeding system, which is analyzed by using the Finite Element Method (FEM). In this study, the location of the maximum stress and deformation is demonstrated and checked, natural frequency and corresponding vibration modes is extracted and analyzed respectively, and the way to build finite element model is simply conducted. Furthermore, vibration testing of the feeding system in X, Y, Z-Direction is carried out respectively, both the theoretical analysis and test results show good agreement with each other. Finally, some conclusions and reviews are made based on the analysis results, which provide some reliable basis for the reasonable operation and static and dynamic characteristics’ improvement for the feeding system.

On the basses of analyzing the defects of variable blank holder force hydraulic press on construction and its rigid being not enough,the realization of designing method,working principle,hydraulic and system for ne controlling w type upper multi-point deep drawing with variable blank—holding force controlled by computer was introduced.In order to verify the effect of application of this set up,the testing results of deep drawing a rectangular box and a cylindrical cup formed component was presented. The results show that the equipment has low cost, general in using and optimal efficient of controlling.

Due to the complexity of sedimentary process of the strata, the distribution of porosity in clastic rock is not homogeneous but random. From the point of microscopic structure, pores in reservoir rock are fractal, and the fractal dimension can describe quantitatively the complexity and the heterogeneity of pore distributions. Geographic Information System (GIS) is a kind of technological system collecting, storing, managing, computing, analyzing, displaying and describing the geospatial information supported by computer software and hardware. In the last 15-20 years, GIS have been increasingly used to address a wide variety of geoscience problems. This paper first calculated the pore fractal dimension in three casting thin sections of clastic rock which came from cores of FengTan1 Well and FengCan3 Well in Dangfeng-Xinghua, JiangSu Province using box-counting method, then predicted the porosity according to the porosity fractal model of rocks in GIS environment. In the last we compared the fractal porosity prediction results with mercury experimental data, and we saw the differences were not significant, so the method in this paper to predict porosity of clastic rock is easy to implement and has high precision.

Simulation environment of the mobile Ad Hoc network is built by applying NS2 simulation software. The simulation data indicates that AODV routing protocol is better than DSDV in throughput, fairness and stability. In the underwater network environment where the nodes are in Low-Speed movement, the data transfer rate of AODV routing protocol is higher than AOMDV. To a certain extent, AODV is more suitable for application in underwater environments.

An alkaloid compound, lappaconitine Hydrochloride, was synthesized with lappaconitine which was isolated from the root ofAconitum sinomontanum Nakaiin Gansu province in China. The structures were elucidated by IR,NMR, Anal. and X-ray diffraction analysis. Crystal data: C32H47ClN2O9,Mr= 639.17, space group monoclinic, P21; a=10.665 (7) Å, b=12.178 (7) Å and c=12.214 (7) Å; β=91.003 (10)°, Z=2, Dx= 1.338 mg/m-3,F(000)= 684,µ=0.18.00 mm-1, V=1586.1 (16) Å3; R1=0.038,wR2=0.087, Flack parameter x= -0.12 (7). RingA, B, C, D, EandFrespectively present boat, chair, envelope, boat, boat and envelope forms. The absolute configuration was determined as 1S, 4S, 5S, 7S, 8S, 9S, 10S, 11S, 13R, 14S, 16S, 17 R. And the analgesic potential has been investigated in a mouse model of acute pain. The result exhibited that the analgesic effect of the compound is worse than lappaconitine hydrobromide.

Traditionally, highway engineers use pencil and ruler to lay out lines and curves over contour maps for highway geometry design. Numerous calculations of stopping sight distance, minimum turning radius, and curve alignments are required during the design process to ensure safety, to minimize economic and environmental impact, and to reduce construction costs. Engineers usually perform iterative computations manually during the design process to meet design criteria and environmental constraints. The traditional process of highway geometry design is cumbersome and time consuming. The traditional approach limits engineers from taking a broader perspective in the overall highway geometry design process. Current method of three dimensional (3D) has nothing to do with highway design process. CARD/1 was developed to enhance the learning experience for highway engineers. This tool allows engineers to design the highway efficiently and to modify the design easily. A 3D highway geometry model can be generated by the software at final design to allow engineers to place themselves in the driver’s seat and maneuver through the designed highway at maximum design speed. Some key technologies of highway design with 3D-animaion based on CARD/1 was discussed in this paper.

As friction pair, ZCuPb20Sn5 and No.45 steel are most in use in gear motor under oil lubrication. In order to investigate the tribological characteristics of ZCuPb20Sn5 and No.45 steel under emulsion lubrication, the authers tested them on MMW-1 friction and wear tester with sample pin and thrust ring. The relationships between the friction coefficient and the load, the friction coefficient and the speed, the wear rate and the load, the wear rate and the speed were provided. The worn surface of ZCuPb20Sn5 were investigated by means of scanning electron microscope. The results showed that, alone with the raising of the load and the speed, the wear rate of ZCuPb20Sn5 increased, but the friction coefficient reduced.

On the basis of research on the theory of non-circular gear transmission and the working principle of gear pump, this paper puts forward the construction principle of a non-circular planetary gear pump. The discussions focus on the construction, working principle, structure types and the pitch-curve of the non-circular gears. The study indicates that the non-circular planetary gear pump has big discharge, good flow characteristics and low noise, and it can be widely used in hydraulic system.

Silicon dioxide films; radio-frequency magnetron sputtering; annealing temperature Abstract. Silicon dioxide (SiO2) films are fabricated on single crystal silicon substrate by radio-frequency magnetron sputtering (RFMS) technique and annealed in electric furnaces at 800°C and 1180°C to form uniform, transparent and compact silica. The surface morphology and roughness of the films are characterized by an atomic force microscopy (AFM). X-ray diffraction (XRD) is employed to analyze the crystalline of the thin films. The chemical composition after annealing is analyzed using X-ray photoelectron spectroscopy (XPS).

Brake piston is a huge demand non straight wall cavity part for the typical automotive industry; the traditional processing method is machine processing, or preforming by cold extrusion, and then machining. In this paper, the combined cold precision forging method of cold extrusion and spinning was proposed, which might improve the overall performance of parts and reduce costs. The rigid plastic finite element model of cold extrusion and spinning was established to simulate the forming process. The results showed that the combined cold precision forging method was available to manufacture non-straight wall cavity piston.

The nucleation and crystallization of Li2O-Al2O3-SiO2(LAS) glass ceramic with one(P2O5, TiO2, ZnF2) and two nucleating agents(P2O5+TiO2, P2O5+ZnF2) are investigated by the differential thermal analysis(DTA)，X-ray diffraction(XRD) and the scanning electron microscopy(SEM). Research results show that the LAS glass ceramic with nucleating agent of P2O5can obtain ideal micro spherical crystal grains and the crystallization behavior can be better controlled.

According to the blasting monitoring of the main tunnel at hidden digging section of Tuandao Second Road exiting ramp in Kiaochow Bay Cross-harbor Tunnel, the paper shows the influence of vibration on the close-spaced main tunnel. Based on the monitoring results of vibration velocity and vibration frequency in the vertical, horizontal radial and tangential direction, we find that the maximum value of vibration velocity in the main tunnel appears in the range of 5-20m in the rear of the ramp corresponding work face. The magnifying effect of the vibration velocity in the rear of the work face is more obvious than the front in the horizontal radial and tangential direction, and the attenuate effect appears in the front in the vertical direction. The attenuate effect of horizontal radial vibration frequency in the main tunnel appears in the rear of ramp work face. The attenuate effect of vertical frequency in the excavated section is more obvious than the unexcavated.

Organotin catalysts were modified with sodium molybdate, sodium tungstate and sodium vanadate, and the modified organotin catalysts displayed high activity in transesterification of dimethyl carbonate (DMC) with phenol into diphenyl carbonate (DPC).

This paper investigated the friction and wear behaviors of nylon rubbing against steel discs with helical, parallel and multidirectional textures respectively. The results indicated that friction coefficient, friction temperature and wear rate of couple using helical texture steel disc as counterpart were higher than others. Abrasive wear was the primary mechanism of the three couples. Nylon surface roughness increased after rubbing against helical texture steel disc, but decreased after rubbing against parallel and multidirectional texture steel discs. The roughness of both helical and multidirectional texture steel discs increased slightly after test, while the roughness increase of parallel textual steel disc was significant only at regions perpendicular to the rotating direction due to adhesion of nylon transfer film.