Abstract:The regenerative braking process of hybrid electric vehicles (HEVs) cruising downhill was analyzed. Based on the charging efficiency, temperature model of battery, and efficiency model of the generator, instantaneous and global optimal control strategies were proposed, with the goal of maximum of instantaneous regenerative braking energy and total regenerative braking energy respectively. Regenerative braking energy efficiency on roads of differing slopes and slope lengths were obtained. The results show that global optimal control strategy is better than instantaneous optimal control strategy, and the steeper the slope or the longer the slope is, the more distinct the increase of regenerative braking energy efficiency with a global optimal control strategy is. The influence of battery temperature on efficiency of regenerative braking energy of HEVs was also discussed.

Abstract:Based on the braking theory of conventional vehicles and high efficient energy recovery and security braking, a control strategy for braking energy distribution and regenerative braking of a 4WD hybrid electric vehicle was proposed. Considering limiting factors, such as motor and battery efficiency, a simulation model of a regenerative braking system was built and a simulation of typical braking conditions was conducted. The simulation result shows that the highest energy recycle ratio can reach 87.5%, 47.8％, and 28.6％ when z is 0.1, 0.3, and 0.5, respectively, at 30 km/h. The control strategy for braking energy distribution and regenerative braking can satisfy demand for vehicle braking and obtain high regenerative energy.

Abstract:Focusing on the fracture issue of single cylinder engine crankshafts, a threedimensional solid model was built in CATIA. Pretreatments, such as plotting grids, were carried out through Hypermesh, and finite element analysis was done using MSC. Patran/Nastran. The results show that the fatigue safety coefficient cannot meet demand when nodular iron is the crankshaft material. This finding verifies the theoretical possibility of crankshaft fracture. A crankshaft using 40Cr theoretically would not fracture because the fatigue safety coefficient could meet the demand. Simulation correctness was verified by a 400 hour engine reliability test.

Abstract:The 3RPS parallel mechanism under unsteady conditions was studied. By establishing geographical coordinate systems and connecting the position of the stabilized platform with the motive vector, operational formulas between normal vectors in upper and rod length were deduced, and the inverse solution derived. The character of velocity and acceleration was analyzed and the trajectory of work space plotted. Analysis indicates the time function of the rod length and the surface of the work space's trajectory are smooth, and no singular position has been found.

Abstract:We present a method for computing annular slice deflection. The physical model of throttle slice was built. The equation for deformation under a uniform load was deduced by using a deflection differential equation for throttle slice and boundary condition, which was convenient for theory analysis and engineering application. Equation correctness was validated by comparing the approximated result in the existing technology. We subsequently studied the rules of different loads, structure parameters, and material characteristics of throttle slice influence on the deformation at any radius. The equation and conclusions can serve as references for accurately designing shock absorber throttle valves.

Abstract:Twelve typical faults and fuzzy treatment of nine symptom parameters were analyzed. A fault diagnosis method for a fuzzy Kohonen neural network was proposed based on diagnostic working principles and specific features of a Kohonen neural network. The application of the method shows the following merits: a selflearning function, rapid operating speed, and strong grouping capability. The fuzzy Kohonen neural network can diagnose single and multiple faults. It is an effective and suitable method for fault diagnosis of the regenerative heating system of the steam turbine unit.

Abstract:According to the demand on just in time(JIT)distribution of chain assembly manufacturing enterprise, cost optimization of backup storage and distribution betimes were analyzed. A backup storage optimization model was formulated and quantitative analysis of the JIT backup storage optimization technology for the process of logistics distribution was carried out. The optimized distribution technique to realize JIT distribution was studied, and the distribution model of logistics center and the distribution algorithm flow were established. Finally, the proposed models were applied in the planning and construction of a logistics center of an electric appliance set chain enterprise with satisfactory results.

Abstract:An autoaccumulation heat model of material beds was constructed with reference to the iron ore sintering process. The effects of the thickness of the combustion layer and the heat distribution ratio in material beds were studied. Simulation results show that the heat of the material beds declines as the combustion layer thickness increases and heat increases as the distribution of calories in the preheating layer increases. Dividing the 300 mm bed into 3 layers, the ratio of heat accumulation in the upper, middle and lower beds is 1∶1.08∶1.13. When the model is applied to the rational distribution of sintering fuel under laboratory conditions, the amount of fuel used is reduced.

Abstract:Q345B (containg Nb) is the sort of high strength low alloy (HSLA) steel which is sensitive to cracks. We analyzed the influences of C, Nb and the secondary cooling water flow rate on the cracks in the casting blank and the reasons for crack formation. Based on those results, we optimized the secondary cooling water distribution system in the process of continuous casting through industry tests and proposed a low cooling water distribution system and uniform cooling. The results show that when the temperature of a casting blank is above 950 ℃, it can prevent the cracks effectively, reduce the generation probability of cracks, and enhance the quality of casting blanks by 80%.

Abstract:Four samples of waste concrete with crushed limestone as coarse aggregate were collected from four different demolition sites. Each sample was crushed into particles which were then screened by sieves to remove smaller particles of given size. The residue was retained for use. Most of the residue was the crushed limestone; it was used to replace natural limestone as the calcareous raw material to produce cement clinker. These four clinker samples were compared with the similar Chongqing Lafarge cement clinker and some selected Portland cements on the market. The comparison results of XRD indicated that the XRD characteristic apex of the four principal compounds in the usual cement clinkers, C3S, C2S, C3A and C4AF, are strong enough in the clinkers produced by the waste concretes. All the free CaO content in the clinkers produced by the waste concretes was less than 1%, meeting the requirement of a given Chinese standard. It can be used to prepare Portland cements with strength grade of 52.5. The experimental results offer theoretical and technological guidance for efficiently reusing waste concretes.

Abstract:Pt and Cr codoped NanoTiO2 film was prepared by the solgel method. The film was characterized by AFM, XRD and UVVis. The experiment showed that when the average TiO2 film diameter is 32 nm and the film thickness is 290 nm, the rate of photodegradation is 95% in 2.5 hours. Additionally, when the optimal codoping ratio for PtCr is n(Pt): n(TiO2) equals 0.03% and n(Cr):n(TiO2) equals 0.4%, the photodegradation of methylene blue for NanoTiO2 film can be enhanced. The photocatalytic properties of Pt and Cr codoped NanoTiO2 film is better than that of pure TiO2 and Pt, Cr separatelydoped TiO2 film.

Abstract:The microhardness method was used to achieve plastic deformation in grain scales in polycrystalline pure aluminums. Characteristics of the deformation structure near indentations were investigated before and after annealing. The different morphologies of slipbands near indentation areas were viewed only after annealing. Within the slipband areas the numerous orderly arranged ends of the dislocations were identified. During experiments, we observed the phenomenon of slipbands across aggregate areas in grains. We discuss reasons for not discovering recrystallization in the deformed specimen after annealing. We also discuss factors such as temperature and time of annealing, reduction and grain orientation, which have influence on the formation of slipbands. The experimental results show that, being different from global deformation for materials, the mode of transgranular deformation can be used conveniently to study the morphological features of deformation and recrystallization of polycrystalline materials and related influencing factors. 

Abstract:For the traditional dyadic wavelet transform, a lot of boundary treatments are needed when the data length is not 2 of integer power. Aiming at such a limitation, a new adaptive optimization wavelet transform algorithm was proposed. The core idea is analyzing the pending data to obtain the optimal approximate length, hence optimize the boundary treatment, while analyzing the optimal approximate length to select the wavelet transform bases adaptively. Compared with the traditional dyadic wavelet transform, the proposed algorithm hashigher speed, less boundary treatment, and greater data compression, etc. An image compression example was given to demonstrate the feasibility of the proposed algorithm.

Abstract:Impulse effects on system stability are complex; namely, impulse may stabilize a system, or drive a stable system to oscillation or even chaos. We investigated the stability of impulsive cellular neural networks with time delays. By using Lyapunov functions, several conditions guaranteeing the global exponential stability of a system are established. It is shown that even if the impulsefree system is unstable, the impulsive system can be globally asymptotically stable if the impulses satisfy the conditions. A numerical example is given to illustrate the correctness of the theoretical analysis. 

Abstract:A novel approach for 3D modeling was developed. It used form feature to represent the share model, parameterized the form feature, and established its parameter list. Any change of the share model was viewed as the parameter modification of the form feature to modify the parameter list, and the new model was recreated through accessing the log of feature modeling. Based on it, a framework which supports synchronous Internet based collaborative design among members in distributed design teams was presented. It was composed of the 3D share modeling network feature modeling server, feature modeling clients, and the standard communication protocols. All the clients use the same server to maintain the 3D feature modeling, guaranteeing data consistency, keeping all clients uptodate, and managing all communications.

Abstract:We proposed a fast iterative algorithm for the multisection signals with the same length and known frequencydifference to increase precision and realtime performance of frequency estimation for multisection stationary signals while extending the applicable ranges of the existing methods. The algorithm includes the following technical features: The parameter matrix for frequencydomain analysis was generated to treat the unequal frequencies of different sections; The phasedifference compensation factor matrix was designed to obtain the frequency spectrum as well as the phasecontinuous signals; The search frequency sequence was generated to amend the unknown parameters in the phasedifference compensation factor matrix while obtaining the frequency spectrum amplitude matrix in a specific form; and, indirect iterative computation was adopted to improve the realtime performance of the algorithm. In addition, five important properties were given and proven to demonstrate the correctness of the algorithm. Simulated experiments were carried out under various complicated application environments. The results show good universality, noise immunity, realtime performance and better frequency estimation precision compared with the existing methods.

Abstract:To improve the estimation precision of the carrier frequency offset in a multipath fast fading environment, the performance of the frequency offset tracking algorithm using a pilot subcarrier was studied extensively. Comparing with the frequency offset tracking algorithm based on a cyclic prefix, a frequency offset tracking algorithm using a pilot subcarrier can not only derive better frequency offset tracking performance in the AWGN channel, but also obtain exact frequency offset estimation in multipath fast fading channels. The algorithm using a pilot subcarrier therefore is more suitable for frequency offset tracking in the multipath fast fading channels.

Abstract:OGSADAI is a middleware that provides universal data access for heterogeneous data sources with network services. It unites access and control of scattered and heterogeneous data to one logic data source and shields the database driver, data formats and communication protocols of the heterogeneous systems for users. Thus, the heterogeneous data source may be accessed and controlled as a single logic source, making it more convenient to access and integrate the special data source. To extend OGSADAI to support heterogeneous data access and integration services, new activity classes were designed to manipulate the data. Serverside activities were created to process the data, while clientside activities were created to build execution documents and data conversion based on XML Schema. 

Abstract:Long span halfthrough arch bridges have the flexible space structure. Wind loads on the arches are usually the key factor to the whole bridge. Taking an example of the Chongqing Caiyuanba Yangzi River Bridge in P. R. China, wind tunnel tests of single arch and double arches section models were conducted. The results of a single arch in the smooth flow show that arch drag variability is small, and the lift and moment variability are significantly large. The results of double arches testing show that the static forces of the windward arch are similar to the single arch. The three force coefficients of leeward arches vary with the space width ratio and the angle between the two arches. Static forces testing was simulated by the CFD software FLUENT. The static forces from the testing and the simulation were compared. The results show that the values match quite well with testing, and the drag forces mainly varied with the space width ratio.

Abstract:There are no clear design standards for the concealed beams or reinforcements under partitions in big and thick slabs which often appear in contemporary reinforcedconcrete residential buildings. Designers have to rely on engineering experiences to design such concealed beams or reinforcements. We built a local finite element method model of a real building in ANSYS. The model included shear walls, big slabs and partitions, and the underlying reinforcements. The element for reinforcement was Link8, and the others were solid elements. Specifically, the element for big slabs was solid65 which can asses the nonlinear behaviour of concretes. Based on analysis results, we discuss the internal forces of big slabs, partitions and reinforcements. We offer suggestions for the design of reinforcements and selection of partitions.

Abstract:Methane drainage is an effective technological approach to manage methane in an integrated fashion. Based the actual conditions of the 11031 mining face of the Zhongling coal mine in P. R. China, we divided the origin of methane into three categories: methane of the coal mining layer, methane of the adjacent coal layer, and methane in the goaf. Combining current techniques for managing methane in the mining face, we analyzed the effects of seven methods for draining the methane: through the coal layer borehole, the sector borehole, the crossborehole, the high level borehole, the largediameter borehole, the pipe buried in the goaf, and a special return airway. We suggest improvements for implementing integrated control in the threedimensional space by the control principle of dividing the sources. We provide references for other projects.

Abstract:Underground streets have been developed in cities with land shortages. We simulated the dynamic distribution characteristics of smoke flow and temperature from fires under natural conditions in underground streets. The experiment was carried out at the Sichuan Fire Research Institute of Public Security Ministry, P.R. China. A 500 kg fire source was used in a real underground street. Temperature distribution at different heights and personnel escape routes are shown in two typical sections. The comparison between the computer simulation data and experimental data validates the simulation. This study provides a valuable reference for fire assessment of underground shopping streets.

Abstract:A building cost estimation model was established based on back propagation (BP) neural networks. The project characteristics determining the cost estimation were obtained from expert experiences. Based on the analysis of 15 typical actual project samples, the BP neural network model subsequently was developed with the EXCEL macrocommands to simulate the nonlinear relationships between the project characters and the costs. The model was applied to the cost estimation of actual projects. The results satisfy the requirements of cost estimation. This new method for cost estimation is efficient and accurate.

Abstract:We derived the cost index value and cost formula of watersupply and water purification in small towns in Chongqing, P. R. China, based on the economic index of domestic watersupply plants, the cost model of domestic and overseas economic indices, and local labor and materials prices. Investment estimation indices for water supply plants in western small towns subsequently were obtained according to the equipment transportation rate and adjustment coefficients in other areas of western China. We analyzed the cost of producing water in watersupply plants in small western towns based on the cost structure analysis and the cost model of investment index, and subsequently derived the unit cost for producing water.