To improve and stabilize the service life of hotforging die fabricated by cast die steel, the failure modes and mechanism were analyzed. Results show that different failure modes and lives are dependent on the material composition and subsequent processing. Improper material composition and processing can cause earlier fracture failure and short life happened to the hotforging dies. With improvement of material composition and processing, the failure modes demonstrate predominately elevated wear and plastic deformation, and no earlier failure occurred, leading to a considerable improvement of service life and a stable number of 6000~7000 times, 80% more than forging steel dies.

A kind of waterglassgel enhanced foam system used in the deep profile control of typical heterogeneous reservoir was investigated on its gelling feature, microstructure, and plugging performance in the rock core. Experimental results show that the reaction between hydrochloric acid and sludge under airtight condition is an equilibrium reaction, the reaction rate decreases exponentially with the increase of the initial pressure, the system gelling time increases with the decrease of the pH value, and the plugging performance of the waterglassgel enhanced foam system is superior to that of ordinary foam system due to the small foam diameter and high interfacial film strength.

Nanocomposite was prepared by nanoAl2O3 and ethylenevinyl acetate (EVA) resin. The dispersibility and structure of nanoAl2O3 in EVA matrix were characterized by FESEM, FTNIR and SEM. The effects of the content of nanoAl2O3 on the mechanical properties of the nanocomposite were studied. Experimental results show that nanoAl2O3 particles with size of about 20 nm are dispersed in EVA matrix, linked with EVA through chemical bond, and the fracture machanism changed correspordingly. With 0.5% Al2O3 addition, the ultimate tensile strength is improved by 13.0%; with 1.0% Al2O3 addition, the fracture elongation is increased by 13.3%.

To realize the virtual development of the automobile products, a multibody system dynamics simulation model was built for a certain domestic passenger car by means of a redeveloped module of ADAMS/CAR. According to the national standard and the test evaluation method on the vehicle steering stability, the simulation tests under typical working conditions such as steady steering and steering returntostraight ability test were performed and discussed. Comparison between the simulation and the real car tests shows that maximum difference of the main parameters was less than 10%. For the performance indexes which were imperfect both in the real car test and in the virtual car simulation, ideal simulation results could be obtained after adjustment of the parameters.

To analyze the driving stability of the tractorsemitrailer, a coupled system composed of single point preview driver model and 3degreeoffreedom nonlinear model was suggested to simulate it. By applying Lyapunov linear approximation theorem, the characteristic root locus of system parameters and the effects of driver preview time and cornering stiffness on the critical vehicle speed were linearly analyzed. Analytical results show that the tire cornering stiffness significantly affects the critical vehicle speed of tractorsemitrailer, the speed goes up with the increase of cornering stiffness, showing a nonlinear relationship between them. Different preview times correspond to different critical vehicle speeds, and there is an optimal preview time.

A type of flat heat pipe with micro rectangle grooves was developed. The configuration and working principle of this type of heat pipe were discussed and the capillary limitation in the heat pipe was deduced theoretically. The effects of the parameters such as the heat flux, the working temperature, the working liquid and the inclining angle on the heat pipe were studied experimentally，and the heat transfer characteristics, the empirical correlations for the heat transfer coefficient of the evaporator and condenser surface were obtained to help the engineering design. The study indicates that the micro rectangle grooves flat heat pipe is characterized by high heat transfer capability with good prospects for cooling electronic components.

The experimental study on homogenous charge compression ignition(HCCI) engine fueled with ethanol was carried out on a single-cylinder engine modified from the CA6110 diesel engine. The preheating intake air and EGR were taken as the control parameters of fuel ignition. The results show that HCCI can be obtained in the range of air/fuel equivalence ratio λ=1～9,but the HCCI operation range expressed by λ and EGR ratio is limited by knock and partial combustion. The maximum obtainable indicated mean pressure of HCCI combustion of the ethanol is 0.6 MPa, and the indicated thermal efficiency is 60%. Only little NOx is formed, but the unburned HC and CO emissions are significant.

A largetravel highresolution step rotary microactuator with a discrete layout was developed based on the step moving principle. A flexible electromagnetic hinge was used to realize the anchoring/lossening of the rotor and a piezoelectric pile as the driver and a flexible hinge was used to transform the linear motion of the piezoelectric pile into the rotary motion, thus a precise largetravel step rotary actuation was realized. Experiments show that the developed actuator is characterized by fast anchoring, high resolution, and large travel, being applicable in the sophisticated micromanipulations.

Facing the problem of microdrill snapping easily during drilling, a dynamic model of microdrilling spindle system was built by using Timoshenko beam element according to rotor dynamics. The model included the effect of the eccentricity of spindleclampdrill system, the drilling thrust, the system rotating inertia, the gyroscopic moments, and the bearings on the bending deformation. The minimum life section was figured out by the model, and the influence of the fixed length of the drill, the stiffness and damping of bearings, the speeds of spindle, the system eccentricity, the drilling thrust, the drilling torque on the stress of minimum life section were performed. Several measure to avoid microdrill snapping were proposed in microdrill design and practice.

Two guidelines were defined to evaluate the selective assembly quality: matching rate and assembly precision, and two computeraided selective assembly methods were suggested: the matching according to the average deviation of the closing link and the matching according to the ideal size position of the closing link. The matching rate of the suggested two methods were compared for the assembly size chaims with different number of the forming links, with different number of the forming link parts, and with different deviation distribution types on the assumption that the closing link tolerance of the selective assembly is a tenth of that calcalated by the extremum method.

On the basis of summarizing current fractal dimension algorithms, the random midpoint replacement algorithm was employed to obtain interpolating point according to the fractal features of remote sensing image ，so the current widely used triangular prism method was improved. The simulation results with real aviation remote sensing image show that the improved method effectively keeps the image fractal features and can obtain more accurate fractal dimension.

By the construction of a LyapunovKrasovskii functional, the global exponential stability for a kind of neural network with multiple timevarying time delays was analyzed. Without the assumption of the boundedness, monotonicty, and differentiability of the activation function, a new sufficient condition that guarantees the uniqueness and global exponential stability of the equilibrium point independent of time delays was obtained. This sufficient condition can be expressed in a form of linear matrix inequality for easy verification. The effectiveness of the proposed method was proved by some remarks and comparison with the results in other literatures.

A novel method based on the redevelopment of Auto CAD was presented to establish an analytical model of the DEM from the CAD model of machine part. The integration of CAD software and self developed analytical software of the DEM for performance of machine part was implemented in order to realize the proper combination of mechanical machine parts CAD design of granular materials and DEM analysis. This integration plays an important role and provides a basis for the design, performance analysis, design modification, and reanalysis for the machine parts.

Facing the problem of user equilibrium traffic assignment, a solution for the route traffic flow based on the FrankWolfe algorithm was proposed to avoid enumerating all routes of the network. Under the conditions that a group of destinationbased link traffic flows satisfying the user equilibrium and the shortestpath set of each OD (origindestination) pair of the traffic network were known, a group of user equilibrium path traffic flows can be figured out by the proposed algorithm, and it was proved effective by numerical example. Compared with other methods, the proposed method is superior in memory requirement, calculating results, and computational speed.

To organize the resources of the urban integrated traffic information platform (UITIP) effectively in ovder to provide a powerful support for the data processing, on the basis of analyzing the storing need of UITTP, the data storing framework of UITIP based database and data warehouse techniques was proposed. The key techniques, central database and historical information data warehouse, were discussed in detail, providing theoretic and practical reference to build UITIP.

Along with violent increase of business operation data capacity, traditional logistics decision support system (LDSS) is hard to meet with the corporation requirement.To solve this problem，the frame of LDSS for multimodal transportation based on data warehouse(DW) was put forward by combining the characteristics of DWwith the requirements of decision support system. The frame of the proposed system consists of three layers, foundation layer composed of model base system and database system, processing layer composed of database warehouse, and application layer composed of online analytical process (OLAP), expert system and data mining. This system can be applied for quantitative and qualitative logistics decisionmaking support. It provides effective measures to realize harmonious operation of logistics system and to strengthen the effectiveness for logistics enterprises decisionmaking.

The fundamentals of the chaos theory were introduced from the chaotic phasespace reconstruction, then the chaos forecasting method and its application in the traffic conflict flow forecast were studied. Then a case study of a crossroad traffic conflict flow by means of the chaos forecasting method was performed, and the forecasting method and results were evaluated by the gray error checking. The evaluated results show that the chaos forecasting method is effective in forecasting the traffic conflict flow.

Biomimetic information in cuticles of some typical soil animals was extracted by observing under SEM. The reverse manufacturing technology and biomimetic shopemodified technology was employed to solve the problem of shoe soles adhesion, and its experimental system was designed. Four factors likely to influencing soil adhesion were considered, and every factor includes three levels. The four factors were the height h, radius r, spacing d and distribution of spherical cap σ. Soil adhesion test was proceed using L9(34 ) orthogonal experiment. The results of contrastive experiments show that at the same condition some biomemtic shoe soles had effect on antiadhesion and antiresistance obviously. When the factors were h=3.0 mm, r=4.0 mm, d=10.0 mm and σ adapt progressive increase in distribution, adhesion reduction is up to 8.27% at most.

Facing the complexity and application difficulty of momentrotation (Mφ) hysteretic model in the dynamic time history analysis on the endplateconnected multistory antiseismic steel frame, domestic and overseas Mφ hysteretic models about endplate connection were summarized, and suggestions on the standard details of semirigid endplate connections used in the multistory antiseismic steel frame were proposed to ensure the joint strength and ductility. For such endplate connections, a 4parameter kinematic hardening Mφ hysteretic model was proposed, and the corresponding detailed calculation method was given. The calculation results were compared with those obtained by relevant cyclic loading test results, and the validity of this proposed model was verified.

Taking the main landing gears of fighter and transport airplane as example, the fatigue life was estimated by means of the Miner’s rule and the spectrum of the real measurement. The computed results show that the landing damage of the fighter and transport airplane is of 75% and 60% of the total damage, and the landing damge of the landing load of the transport airplane is of 40% of the landing gears damage. The fatigue damage properties can provide important information for the reliability design and the structural optimization.

The improvement for the classical recurrence method of fatigue strength reliability was disscussed. The computational formulae for accumulation damage degree and invalidation probability caused by different stress level was presented. Comparing with the existing method, the present method has the advantages of the conciseness and fast computation. The numerical tests show that the invalidation probability obtained by the present method is equal to those obtained by the existing method.