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A digital closed-loop control system with all digital phase locked loop (ADPLL) is designed and optimized, in order to improve the bias stability and transient response of the gyroscope. The nonlinear mathematical models for the closed-loop amplitude and phase control system are established. The linearization method is applied to analyze the nonlinear models. The control parameters of the drive loop are optimized. The experimental results show that the phase deviation between the demodulation reference signal of the drive loop and the sense signal is less than 0.25° in the temperature range from-40°C to 60°C, within 0.15° of the variation. At room temperature, the overshoot amount of the gyroscope control system is 4.5% with setting time of 0.12s. The bias stability is 1.45°h. Compared to the analog control scheme, the digital control system has advantages of short setting time, small overshoot, short phase locked time, large locked range, high phase precision, etc.

In Line Balancing principles, the total workload in the assembly process is divided as evenly as possible among the workstations, without violating the sequences and relations in the assembly operations. Line balancing is important in an assembly system as it balances the line and increases the efficiency, as well as the productivity of a system. A case study was conducted in the assembly line of an electrical accessories manufacturer in Malaysia. The cycle time for each station was recorded, and the standard cycle time was estimated. The productivity, as well as the efficiency of the current assembly line, were studied. In terms of the productivity, the performance of the current systems was 500 units/worker/day, while the expected productivity was 600 units/worker/day. An assembly line setting was proposed based on the Line Balancing Method; the productivity for the proposed line increased to 671 units/worker/day, or in rough additional increase around 34%.

Electrohydrodynamic Direct-Writing (EDW) provides a simple and rapid way to print micro/nanostructures from viscoelastic solution, which meets the demand in the development of all-printed organic electronics. Overlapped printing of different functional materials to build up multi-layer devices displays excellent advantages in the flexible electron. The 3D multi-layer devices as well as flat interconnection can be fabricated on the flexible substrate directly via EDW technology. The technology of EDW utilized stable charged jet to print orderly conductive and insulator micro/nanostructure. Silver ink is used to print conductor connection, and polyvinylpyrrolidone (PVP) solution is used to fabricate insulator layer. Multi-layer interconnection can be printed layer by layer on the polyimide (PI) flexible insulator substrate. The resistance of top and bottom conductor connection was 6.1Ω and 5.9Ω, respectively. The insulator layer demonstrated excellent insulation characteristics between the bottom and top silver interconnection.

As a novel and simple non-contact fabrication method, electrohydrodynamic direct-write (EDW) has been regarded as one of the most potential technologies for large scale manufacturing of flexible and organic electronics. An inducing tip was introduced into the EDW apparatus. The enhanced electrical field between spinneret and inducing tip provided an excellent way to restrict the motion of charged jet, by which the stabilization of EDW jet can be promoted and the disturbances can also be overcome. Charged jet is deposited layer by layer to construct three dimension structure between spinneret and collector. The three dimension structure grows directly to the spinneret by the guidance and restriction of focused electric field. With the help of X-Y motion stage, the motion track of collector can be controlled by the host computer to fabricate designed pattern. The inducing tip provides a good way to increase the stability and deposition accurate of EDW charged jet.

The drainage system of a part of a university campus was tapped using SWMM (Storm Water Management Model). Local drainage discharge capacity was studied under different design storm return period. Results show that flooding and overload at some junctions and in some conduits are doubled with the increase of design rain return period from one year to five year, which may deteriorate the traffic and road base.

With the improvement of people's living standards and life rhythm speeding up, the cardiovascular and cerebrovascular diseases have become a danger to the top killer of the elderly health and longevity.This paper designed an ECG monitoring terminal of family used in telemedicine for cardiovascular and cerebrovascular diseases.The terminal adopted ADS1298 chip as collection simulation front-end, AVR as core processor ,collected the ECG signal and wireless transmission .The monitoring terminal had high common mode rejection ratio, high signal to noise ratio, low energy consumption, small volume, etc .And can real-time transfer the ECG data to the local area network through wireless transmission technology,convenient medical staff grasp patient's ECG data real-time and treatment it in time,this design meets the basic requirement of the portable monitoring.

The feed drive system is important functional components which effects on precision and efficiency of transmission and cost of CNC milling machine tools. So the designe of the feed drive system of economical CNC milling machine tool is researched. Firtsly the general design scheme which includes the transmission scheme and basic parameters of CNC milling machine tool is determined. Then according to the milling force calculated during mill processing, linear rolling guide, ball screw and stepping motor of X axis and Y axis of feed drive system are respectively calculated, selected and checked in detail. Using the Solid works software for 3D modeling and assembly of mechanical parts of feed drive system, By the scheme comparison, selecting the CNC system of Huazhong century star HNC-21 and accomplishing the electrical connection of CNC system.The feed drive system of economical CNC milling machine in the desing is high performance and low cost,and meet accuracy requirement.

In this paper, different numerical methods on tidal current energy extraction of near-field and far-field hydrodynamic response are used to conduct simulation study. And the following aspects are used for simulation, including CFD model is used to establish three-dimensional numerical flume, layout plan of more tidal current energy electric generator with different spaces is designed, changes in near-field hydrodynamic are stimulated as well as the calculated results are compared and analyzed, in order to more clearly understand the influence of tidal current energy generator to the surrounding water flow, which has a certain guiding function for the optimization of tidal current energy generator group and protection for the marine environment and ecology.

Nutrient limiting factors in main soils from oil tree forest land of the south-central region in Hunan Province were assessed by employing the systematic approach developed by Agro Services International and selecting Sorghum as indicate plant in order to evaluate their nutrient status and limiting factors. The results of soil testing showed that the four oil tree forest land soils were low in organic matter, N, P, K was severely deficient, but the available S and Fe were sufficient, the deficiency of Ca, Mg, B, Zn and Mo were rather common. In the tested oil tree Camellia forest land soils, the larger capacity of adsorption and fixation belonged to K, Zn, Mn in Quaternary red soil and to B in Sandstone soil, while the capacity of adsorption and fixation of K, B in Phyllite soil land and P, Mn, Zn in Granite soil was weak. The results of pot experiment showed that its nutrient deficient degree was in the order of N>P>K>B>Mo>Mn in Granite soil; that was in the order of K>P>N> Zn in Sandstone soil; that was in the order of P>N>K>Cu>Zn>Mn>Mo>S in Phyllite soil; that was in the order of N>P>K>Zn>Mo>Cu>B in Quaternary red soil. So P, N and K were the main nutrient limiting factors of oil tree forest land soils in Hunan province, and then followed by Zn, B and Mo. Next field experiments should be focused on the balanced fertilization of N, P, K, and B, Zn, Mo. Moreover, much attention should be paid to make up Ca and Mg.

Kinetic characteristics of chain drive system were investigated in this paper and some corresponding mathematical models were established. In accordance with the theory of chain drive, based on the multi-body dynamics software platform, a dynamic analysis model of timing bushing chain system for diesel engine was established. Chain tension force, chain contact force and chain fluctuation in a rotation cycle at different running speeds were analyzed. By analysis and evaluation these results, the kinematic and dynamic characteristics of the chain drive system during the operation could be effectively recognized, this research results can provide a basis for production tests.

Mechanical expanding is widely used in production of large diameter submerged-arc welding pipes. The pipe is circumferentially expanded to obtain a highly circular shape. But the crack of the metal material often happens under the action of the expanding load. To analysis this problem, it is necessary to analysis the distribution of stress in mechanical expanding forming process. So, mechanical expanding is analyzed using finite element method. Taking the expanding of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the mechanical expanding forming process is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by experiments and a comparison showed a good agreement with experiments results. The maximum mises stress of mechanical expanding is discussed. Thus, the result of research provides a basis to improve welded pipe quality.

Mechanical expanding is widely used in production of large diameter submerged-arc welding pipes. To improve welded pipe quality, it is necessary to analysis deformation characteristic of mechanical expanding forming process. So, mechanical expanding is analyzed using finite element method.. Taking the expanding of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the mechanical expanding forming process is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by experiments and a comparison showed a good agreement with experiments results. The deformation characteristic of mechanical expanding is discussed. Thus, the result of research provides a basis to improve welded pipe quality.

Crimping is widely used in production of large diameter submerged-arc welding pipes. In crimping process, mould is one of the main factors which influences the quality of forming and should be considered at the stage of designing the forming die and process. So, Effects of mould on crimping is researched using finite element method. Taking the crimping of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the crimping forming process is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by product and a comparison showed a good agreement with product results. The stress/strain from simulation is discussed. Thus, the results of research provides a basis to choose mould.

JCO forming is one of manufacture mode widely used in production of large diameter submerged-arc welding pipes, in which JCO forming process is progressive multi-step air bending. In order to improve JCO forming quality, it is necessary to analysis deformation characteristic of air bending. So, air bending is analyzed using finite element method. Taking the air bending of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the air bending is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by experiments and a comparison showed a good agreement with experiments results. The stress/strain from simulation is discussed. Thus, the results of research provides a basis to improve JCO forming quality.

JCO forming is one of manufacture mode widely used in production of large diameter submerged-arc welding pipes, in which JCO forming process is progressive multi-step air bending. In order to improve JCO forming quality, it is necessary to predict springback of air bending. In this paper, air bending is simulated using finite element method, but simulation parameters directly affected prediction precision. So, taking the air bending of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the air bending is simulated by finite element (FE) code ABAQUS. The effects of simulation parameters on springback is discussed. Thus, the results of research provides a basis to improve prediction precision of springback in air bending of JCO forming.

JCO forming is one of manufacture mode widely used in production of large diameter submerged-arc welding pipes, in which JCO forming process is progressive multi-step air bending. In order to design technical parameters, it is necessary to analysis effects of technical parameters on springback in air bending of JCO forming. So, sensitivity analysis of technical parameters on springback in air bending of JCO forming is carried out using finite element method. Taking the air bending of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the air bending is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by experiments and a comparison showed a good agreement with experiments results. The sensitivity analysis of technical parameters from simulation is discussed. Thus, the results of research provides a basis to design technical parameters.

For the study of column-wall connection technology of precast frame-shearwall structure system, four practical connection methods of wall-column subassembly in precast frame-shearwall structure were proposed in this paper. Based on the general finite element software ABAQUS, numerical simulations were carried out on the mechanical performance of the precast and cast-in-situ wall-column subassembly. Results showed that mechanical performance of the precast column-wall subassembly, such as carrying capacities, deformations and failure modes, was almost equal to the cast-in-situ wall-column subassembly. Feasibility of the connection method which this paper proposed is verified preliminarily. The research results can provide theoretical references for related experimental researches, engineering designs and constructions.

To study on the property of the column to wall connection in the prefabricated frame-shear wall structure, these four connection ways are introduced in the article, which are U-shaped ,double straight ,chain buckle, double straight vertical U-shaped bar splicing. Using ABAQUS to simulate, comparing results of four connection ways with the cast-in-situ concrete structure. The results show that mechanical properties of four prefabricated structures are similar to the cast-in-situ structure, but the maximum bearing capacities are reduced.

Reinforced concrete composite beam plays a very important role in the precast concrete structure, composite beam research is critical. Based on the research results about it in China, on the one hand, from the traditional composite beams to the improved ones, the various kinds of composite beams were concluded; on the other hand, the applications of new building materials in the composite beams had been included, which included fiber reinforced cement-based composites, steel fiber reinforced concrete, reactive powder concrete and crumb rubber concrete. Through to the both related tests and theoretical studies, the progress of the composite beams was summarized. Finally, the further research was prospected.

Although the advancement of technology can provide a better and safer working environment to people, sometimes, overconfidence in technology can lead to unavoidable accidents and human errors in the workplace. This study aims to determine the effects of familiarity with office equipment on human errors and accidents in the workplace. A total of 150 surveys were collected and analysed with correlations analysis usingSPSS software version 19.0. The results show that although familiarity can reduce the occurrence of human errors, it cannot reduce the occurrence of accidents in the workplace. While it is now understood that improving one's familiarity with office equipment can potentially reduce their mistakes at work, companies should still be observant of other factors that can potentially reduce accidents in the workplace. This study sheds light on potential possibilities to improve the occupational safety, health and environment of organizations.

Effective thermal management of battery pack is essential for electric vehicle to adapt to different kinds of external environment, achieve desired working efficiency and life cycle of the power batteries. In this paper, a novel thermal management system is designed for battery pack in electric vehicle. Visualized simulation analysis of the thermal management system is carried on under different working conditions by CFD, then the structure parameters will be optimized. According to the conclusion, the thermal management system has been indicated to be effective to ensure an appropriate temperature range and the normal work of the power batteries in electric vehicle.

The high-performance parallel computing (HPPC) has a better overall performance and higher productivity, for a generical large-scale army equipment system of systems (AESoS) simulation, and the runtime efficiency can be multiplied several tenfold to several hundredfold. The requirement analysis of simulation framework of AESoS based on HPPC was proposed. After the simulation framework of AESoS based on HPPC and its key techniques were discussed, the simulation framework of AESoS Based HPPC was designed. it is of great significance to offer certain references for the engineering application in the simulation fields of AESoS based on HPPC.

The high-performance parallel computing (HPPC) has a better overall performance and higher productivity, for a generical large-scale army equipment system of systems (AESoS) simulation, and the runtime efficiency can be multiplied several tenfold to several hundredfold. The requirement analysis of simulation framework of AESoS based on HPPC was proposed. After the simulation framework of AESoS based on HPPC and its key techniques were discussed, the simulation framework of AESoS Based HPPC was designed. it is of great significance to offer certain references for the engineering application in the simulation fields of AESoS based on HPPC.

The traditional segmentation method for medical image segmentation is difficult to achieve the accuracy requirement, and when the edges of the image are blurred, it will occurs incomplete segmentation problem, in order to solve this problem, we propose a medical image segmentation method which based on Chan-Vese model and mathematical morphology. The method integrates Chan-Vese model, mathematical morphology, composite multiphase level sets segmentation algorithm, first, through iterative etching operation to extract the outline of the medical image, and then the medical image is segmented by the Chan-Vese model based on the complex multiphase level sets, finally the medical image image is dilated iteratively by using morphological dilation to restore the image. The experimental results and analysis show that, this method improves the multi-region segmentation accuracy during the segmentation of medical image and solves the problem of incomplete segmentation.

According to the problem such as blurred border of images and lower efficiency caused by present interpolation methods, an interslice interpolation based on the relativity for medical image is presented in this paper. This algorithm makes good use of voxel relativity and structure relativity and then the different methods are adopted to interpolate the different points, In addition, error checkout is introduced to check the mismatching points.The experiments show that the proposed algorithm has less computational complexity and improves the quality of image, at the same time, the result can be used to 3D reconstruction effectively.

For electric magnetic system which contains permanent magnet, its calculation results often has a low level accuracy when using equivalent circuit method .The calculation method of permanent magnet leakage permeance is the key point and needs to be improved. The leakage permeance calculation formulas of bar type permanent magnet are deduced. The magnetic field simulation method and analytical method for calculating leakage permeance of bar type permanent magnet in open magnetic circuit are investigated based on the finite element method. An example is given and the results are validated by experiment. The methods and results can be used to found the equivalent magnetic model with high accuracy.

This paper provided a method and implementation technique about massive amount of data information transmission based on a variety of problems of the UDP communication in poor network. We provided a method based on several deficiencies of traditional method, which could remove the task that would keep the data package transmission in the correct order to receiver in order to reduce the communication burden and improve the stability and efficiency of transmission. A large number of actual tests proved that the improve protocol can transmit the massive amount of data information good although the network speed is below 10K/S which showed the practical value.

Development of china's higher education is shifting from the connotation construction of the expansion, As colleges and universities, In order to meet the needs of the national education strategy, Comprehensive reform must start from the professional, This article from a regional university to build a professional cooperation, The perspective of building experimental zone for comprehensive reform of professional studies.

Undertaking practical education network platform is a network platform with strong practicalness, therere many security issues when developing and operating. From the angle of founding and operating a security website, this article focused on how to found a security operating environment and provide a security system service, put forward the suggest of referring to OWASP(The Open Web Application Security Project), and studied various kinds of security check mechanism. Using the methods above-mentioned can help avoid many faults during the operational process, decrease procedures operational risk, and found a efficient security mechanism.

The image of magnetic field is traditionally obtained by spreading magnetic powder manually or by sparse arrays of magnetic needles, obtaining the images of the magnetic field in different permanent magnet shapes and do repeated tests on the permanent magnet are in need. Based on programmable logic controller (PLC) motion control, the servo control and mechanical system have been built, the control strategy is discussed and the software is programmed. 2D FEM model of a test permanent magnet bar is built. Compared with the FEM simulation results, the system has achieved the goal that spreading magnetic powder quickly and evenly in the appointed area.

Practice is the fundamental soul of innovation and entrepreneurship. Practice teaching is to develop information technology innovation and entrepreneurship diverse talents indispensable and must always be an important part throughout the practice teaching system is an important part of university teaching system. Information technology innovation and entrepreneurship is the very strong practical activities, training model reform and re-light theory of practice, and to build three-dimensional information technology innovation and entrepreneurship diverse talent cultivation practice teaching system.

The HEVC standard is mainly for high-definition and ultra-high-definition video images. The compression performance of HEVC has been further improved, but at the same time coding complexity is also higher than the existing standard. This paper firstly analyzed the architecture of HEVC decoding process and its mainly algorithm components. Then this paper designed how to use the Android NDK to transplant the HM decoding library, and then take the java native interface to resolve the HEVC stream. After decoding the data, this paper converts the YUV data into RGB format for display. The experiment results show that the design scheme is feasible and the HEVC player achieves the basic functions in the Android platform.

The invention relates to building materials field, especially the determination method relates to a concrete root ion content of nitrite. Nitrite as antifreeze in the concrete, early strength agent and rust resistance agent composition is widely used in reinforced concrete structure, the admixture of cement quality generally accounted for 1-3% range, its content is too little and too much will affect the durability and workability of concrete, if insufficient dosage when the early strength, anti-freezing and anti-rust effect is not obvious，otherwise affect the workability and durability，when used as a rust inhibitor and dispersant, insufficient dosage, sometimes, can produce local corrosion and accelerate the macro cell corrosion.Therefore, the determination of nitrite ion content in root of concrete (or mortar) has become the inevitable trend of modern concrete production.

Entrepreneurical informatizational education pays attention to gain experience that is related to it, and is needed to the students who should be leaded to get perceptual cognition about entrepreneurial venture. This is the premise conditions to carry out education startup successfully. We can be consciously known to the students experience about related content, thus, to stimulate the students pioneering innovation consciousness.For the current college students, entrepreneurial education should be focused on changing its employment idea. According to the survey at present,many college students think: employment is his own thing to find work. These old ideas make many college students rather passive when finding a job. Entrepreneurial education is to converse the students the passive employment ideas and initiate to start a business. Students should be encouraged to regard entrepreneurial venture as a career choice,combined with their interests to create the value of life that are expected .

Crimping is widely used in production of large diameter submerged-arc welding pipes. Traditionally, the designers obtain the technical parameters for crimping from experience or trial-errors by experiments. However, it is difficult to obtain the ideal crimping technical parameters with this method immediately at present. To tackle this problem, a new method coupled with response surface methodology and finite element method is proposed to design crimping technical parameters and save the design time of crimping. In this paper, the crimping forming process is simulated by finite element (FE) code ABAQUS. Taking the crimping of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the simulation data from the arrangement of simulation which is constituted by the optimal latin hyper-cube sampling approach is treated as sample point. Four types of response surface methodology which included four-order polynomial function, orthogonal polynomial function, kriging and radial basis function is discussed, where the response surface model based on radial basis function is proved more efficient than other types of response surface methodology to construct surrogate model. The results showed a good agreement by a comparison with simulation results and remarkably predicted the crimping quality. Thus, the presented method of this research provides an effective path to design crimping parameters.

Considering the involving stakeholders in public rental housing construction under the CCIT model, which is the basics of constructing the financial structure and analysing the main body involved in the risk, and then construct the assessment system. This paper proposes a model based on the analytic hierarchy process (AHP) and grey clustering risk assessment method. Firstly by analyzing the clustering index in the financing mode of risk subject, we can quantify the weight of indicators of every layers, and then using the gray clustering to get clustering analysis, drawing the value at risk ,finally , this article quantitatively analyses the CCIT mode in public rental housing construction in the use of the degree of risk..

The dynamic compressive tests of microconcrete were carried out under the strain rate of seismic action. Based on test results, the rate-dependent compressive constitutive model of microconcrete was proposed. In order to verify the accuracy and efficiency of the proposed constitutive model, the dynamic compressive tests of microconcrete were simulated by finite element software ABAQUS. Results show that the dynamic compressive strength and elastic modulus of microconcrete increase with the increasing strain rate. There was no obvious change on strain at peak stress. The compressive stress-strain curves of microconcrete were similar to concrete. The results of numerical simulation approximately agree with test results. The proposed constitutive model can simulate the dynamic compressive property of microconcrete very well.

The health diagnosis of seismic-damaged tunnel seismically damaged is important in recovering traffic lines for seismic relief and recovery. Taking a tunnel damaged tunnel in the Wenchuan earthquake as an example, the methods of safety check is exposed. The non-destructive test showed that the seismic damage to this tunnel included concrete cracks, hidden cavities, and strength deterioration of lining. Several causes induced in seismic diseases were discussed. The rehabilitation technique, which needs not break off transportation through the tunnel, was also put forward. It is hoped that this earthquake mechanics study can enhance the stability assessment and tunnel reinforcement in a highly seismic region.

The weapon and equipment system of systems (WESoS) construction risk analysis is great significance to enhance decision-making and management level of information technology WESoS construction. The concept of "entropy" in the information engineering is using to calculate the entropy, and the entropy weight is used to fix subjective weight, after that Combining ideal point method to evaluate and select the schemes, the best decision of WESoS construction is get. The model is of impersonality and in reason, which provided a simple and practical method for construction risk evaluation of WESoS.

A practical connection method of wall-column subassembly in new precast reinforced concrete frame-shearwall structure was proposed in this paper. Based on the general finite element software ABAQUS, numerical simulations were carried out on the mechanical performance of the precast and cast-in-situ wall-column subassemblies by using concrete damaged plastic model and bilinear kinematic hardening model. Results showed that mechanical performance of the precast wall-column subassembly, such as carrying capacities, deformations and failure modes, were almost equal to the cast-in-situ wall-column subassembly. Feasibility of the connection method which this paper proposed is verified preliminarily. The research results can provide theoretical references for related experimental researches, engineering designs and constructions.

This paper investigated the dynamic pressure distribution on the plates within a wet shift clutch in hydrodynamic machineries for one engagement. The perturbation pressure model, heat conduction model and pressure calculation model excited by thermoealstic instability was developed. And wrote calculation programs with Maple 15 to analyze the influence of two kinds of typical friction materials, different thermal conductivity, different initial engagement speed on perturbation pressure amplitude and its impact on the pressure design margin and design radius. The results show that the margin can be decreased and design radius can be reduced, so power density increased. When the slipping speed is controlled within 16m /s, the radius can be reduced to about 1/2 of the original value.

This article mainly aims at the problem of the video text font size, achieved a algorithm of multi-scale corner text detection, and combined with the characteristic of word usually has the same color, even more precise positions the text area with color clustering way.This algorithm not only detect the game scene, video ads and video news kind of information in words, but also be used for the natural scene of the text of the detection positioning.Finally, test a public data sets, and the test results show that the proposed method can detect and positioning video the text in the complex information.

In the process of ground simulation object maneuver simulation in large-scale operation simulation, an efficient path planning method based on A*algorithm is proposed. By means of introducing all kind of geography factors and security factors into heuristic function, the plan reaching method solves the problem of finding an optimal path under acquiring enemy's situation and terrain data. Experiment results show that it has effectively raised path planning speed of A* algorithm and the scheme is practical and feasible.

This paper works on the dynamic characteristics of implement mechanism of mining excavator. The dynamic model of the working implement is established based on the application of Lagrange's equation. Digging resistant force, crowd force and ore gravity were discussed in detail. A full working cycle is simulated by using Matlab/Simulink. The results show the validity of the established dynamic model and the importance of the dynamic analysis for the mining excavator.

In order to analyze the performance of a certain FSAE racing car with rear wing at different attack angles by virtual prototyping technology. The multi-body model of a FSAE racing car which takes non-linear factors into consideration was built by applying ADAMS/Car. The correctness of the model is verified by comparison with the actual experiment result. By the simulation of the air resistance and lift characteristics of the rear wing, a feasible method to building the aerodynamic characteristics of the rear wing in multi-body model was proposed. Based on these, the crosswind stability of FSAE racing car with rear wing at different attack angles was analyzed, the result shows that the effect of crosswind is reduced with the increase of the attack angle of the rear wing.

High vacuum dry pump is a typical technology-intensive mechatronics product. It is mainly composed of a specially designed gas-pumping structure and a set of very complicated electronic control system. Taking place the conventional dry pump unit, this pump can used in many hi-tech area such as semiconductor industry where oil-free high vacuum is needed. This paper introduces two types of dry pump, including their structures and performances. Some key points related to the development of the pump are intensely discussed as well.

In the last decades, many methods of ANSYS finite element modeling have been proposed. By comparing the two different methods of beam element modeling and entity unit modeling for multistage centrifugal pump rotor, we find that although both methods are insensitive to torsional vibration model, to some extent they affect other vibration models and result in certain deviation in calculation results. Using beam element modeling not only improves the calculation precision, but also saves computing resources. The Appropriate selection of the element type will reduce the amount of input data and computation time.

At first, this paper compared the present some advantages and disadvantages of reactive power compensation devices, and analysis the disadvantages of these devices in practical application deficiencies, then put forward a new kind of reactive power compensation principle. With the development of power electronic devices, this paper put forward a new type of reactive power compensation which based on RB-IGBT of SVC mode, synthesize the advantages of domestic reactive power compensation devices at present, and the prospect of application is very good.