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Under the joint action of dynamic and static loads, the connecting bolts of the top cover of the pump turbine are prone to cumulative damage in local areas such as threads, resulting in cracks or development, and fatigue fracture may occur in severe cases, which will cause serious safety accidents. Therefore, it is necessary to carry out accurate fatigue life estimation analysis for connecting bolts, which has always been a hot spot and difficulty in the industry. This paper introduces several commonly used fatigue life analysis methods of parts, combined with the force characteristics and structural characteristics of the connecting bolts of the top cover, and analyzes and discusses the fatigue life analysis methods suitable for the top cover bolts. Finally, it is believed that the application of stress-strain field strength method can better describe the actual state of the bolt danger area, and the current damage state has an influence on the amount of damage generated by further loading, and the fatigue life analysis of connecting bolts can be combined with the stress-strain field strength method and variable damage linear cumulative damage theory, and the fatigue life and residual fatigue life can be estimated in the design stage or after the phased service of the bolt.

Take the new tidal current energy utilizing device as study object, finite element modeling and simulating of physical process of impacting by tidal current are studied. Further, the physical process of impacting by the tidal current is analyzed, and the contour map of force, cloud picture of pressure distribution, vector diagram of water flow velocity and route map of water flow for the rotating blade are obtained. Our studies have shown that the force in front of blade is uneven, and the force of one end near pillar is bigger, but the force in reverse side is even, as the same time, the flow becomes divergence after impacting blade, flowing to the edge of blade.

This paper presents a representative volume element (RVE)-based modelling method to capture the mechanical behaviour of aluminum foams under compressive loadings. Octadecahedron is selected as a geometric basis shape to form closed cells of the aluminum foams in the microstructured RVE model to simulate the mechanical behaviour under compressive loadings. The stress-strain relationship obtained from the numerical modelling is compared to that from experimental study and agreements between these results demonstrate the validity of the proposed RVE model. Through observing the deformation evolution of cells during a compressive loading process, the failure modes of aluminum foams are identified and analysed using the proposed RVE model. Further the influence of strain rate on the mechanical behaviour of aluminum foams under compressive loadings is numerically studied via a parametric study.

In this paper, a new bionic quadruped robot was proposed by us. The mechanism of robot we analyzed is as a hybrid series-parallel mechanism, so a new methods for constructing the kinematic model of the bionic quadruped robot very quickly and efficiently was introduced. we analyzed the workspace of the legged mechanism by using geometric composition method and numerical analysis method in the following section. Furthermore, the kinematic model of the parallel mechanism of the multi-motion mode bionic quadruped robot was constructed when the robot was in the stance phase, we also construct and solve the inverse kinematic model of the parallel mechanism of the robot, and the simulation results provide a better method for the robot’s workspace analyzing;Finally, the simulation experiment showed that the method we presented above could provide a good support for the multi-motion mode bionic quadruped robot walking smoothly and automatically.

Based on the field survey data,statisticsing and analysising the influence factors of industry flows of science and technology human resources in Shaanxi Province by using multiple linear regression model and Logistic regression model.The results show that: enterprise promotion chance, industry development ability, family factors and change lifestyle these four factors promote or weaken the effect on the flow of talent directly;Age,working ability,professional degree are the constitute factors influencing science and technology talent flow;However, the influence of gender, education, welfare and residential moves is not significant for industry flow of science and technology human resources.

This article is based on the theory of fractional calculus control, and put forward a kind of fractional order PI controller design method for lateral attitude control system of unmanned aerial vehicle (UAV) model. And the unit step response of the control system is analyzed in the simulation to improve the UAV flight control system stability and robustness. Use the controller parameter tuning method and combined with fuzzy reasoning to design IOPID controller, FOPI controller and fuzzy fractional order PI controller. Then, by exploiting Matlab, the frequency domain response and unit step response characteristics of the different control systems can be plotted. The results verified that the designed fuzzy fractional order controller for the attitude control system is effective.

A new ZrCl4-catalyzed method for the preparation of an asymmetrical benzimidazole derivative has been developed. Further alkylation of the benzimidazole precursor with methyl iodide afforded a new monomethine cyanine derivative. The photophysical evaluation showed that the newly synthesized monomethine cyanine compound was non-fluorescent.

Numerical simulation of air flow over urban areas is an effective way to analyze and predict the wind environment. This paper presents two dimensional computer model results concerning the effects of buildings and/or a hill on the wind flow. The RANS equations and RNG κ-ε turbulence model used in the simulation are discretized by the finite volume method. The computational solution is based on a pressure correction algorithm of the SIMPLE-type. The inflow boundary conditions are given by wind tunnel experiment. In the presence of only a street canyon formed by two buildings, the ambient wind is accelerated and slightly curved at the roof level. When there exist a hill and a street canyon, the velocity in the canyon is affected by the upwind hill. Another simulation model, which has a hill and two street canyons, is used for comparison. There is a little difference in velocity between a single street canyon and two canyons in the presence of an upwind hill.

The choice of damage index and quantify of the performance goal is an important part of the theory of performance-based seismic design. This paper introduces research results of shear wall structure damage model at home and abroad, combined with the experimental study on the seismic behavior of shear wall structure at home and abroad, and discusses the application in practical engineering of the shear wall structure damage, puts forward the remains problem to be further in-depth study.

In this paper, we present a scheme to improve immune cloning selection algorithm. The improved algorithm, which is referred to as adaptive cloning selection algorithm (ACSA), is proposed and then applied to function optimization. At first, we present adaptive gene mutation which decides mutation probability of each code point (locus) based on the quality of antibodies and the number of evolution iterations. Secondly, we present an iteratively increasing method from one locus to the all ones, which can be used in function optimization. Then, the cloning selection process of evolution is divided into two-stages. The first step is to increase locus of antibodies. In the other one, the Baldwin effect learning operator is employed. And finally, an experiment is carried out to verify the theoretical analyses on several testing functions.

It remains unresolved to study the relation between the density of wedge and its impact. Fluent is applied to simulate its mechanism with 6DOF model. After the comparison of numerical result and the theoretical, it matches good and then the transient free surface scene is observed. Thus Fluent is able to solve this kind of non-linear problem. And the effect of density of wedge on the slamming character is also studied.

In this paper, a new multi-motion pattern bionic robot was proposed by us. Though we analyzed the robot as a hybrid series-parallel mechanism, the robot is a wheeled-legged robot, and a new methods for constructing the kinematic model of the special four-bar mechanism of the robot very quickly and efficiently was introduced. Then, the kinematic model of the parallel mechanism of the multi-motion mode bionic robot was constructed when the robot was in the stance phase.

At present, under the background of rapid development of education in China, the advantage and disadvantage of the cultural and educational architectural design has become an important material basis for personal training undoubtedly during the process of increasing popularity of higher education .The cultural and educational architecture design not only needs reasonable function, but also needs the latest form and a lot of the sense of place. For moral education infiltration in the professional education, it should to be incorporated in the daily life of students. Through research, good teaching environment can effectively enhance the design professional students' moral education infiltration.

Through comparing the battery management system (BMS) in existence, it concludes that every BMS has its own features, such as, interface, communication, data hand method, and so on. There is no uniform standard in the globe, so the BMS has the compatibility problems. In order to serve the problem, this paper proposed the large-scale and flexible BMS design, which can save the BMS design time and reduce the designer work strength. In this paper, the flexible hardware and software are designed, which can change the software and interface form a new BMS quickly to satisfy the market requirement. The large-scale and flexible BMS design method mentioned in this paper can accelerates the process of the BMS design, shortens the production development cycle, and satisfies the market requirement speedily.

Two β,γ-CX2-5-bromouridine triphosphates (X = F and Cl) have been efficiently obtained from 5-bromouridine 5′-phosphoropieridate via the activation of the P(V)-N bond with 4,5-dicyanoimidazole.

Object-oriented method has been carried on the deep philosophical thinking, starting from thinking mode in combination with the real things, so the mapping relationship between real things and Object-oriented Programming is expounded, the essential feature of Object-oriented Programming is revealed. The objectivity, adaptation, complexity and emergent property of Object-oriented Programming whose intension and extension are enlarged are investigated, at this time, its own development direction is specified. The paper explores Object-oriented Programming from the epistemological and methodological perspective, establishes a theoretical foundation for its scientific practice activities.

To study the effect of ignition mode and position on fragment velocity of azimuthal warhead, a simulation model was established and computed. Simulation analysis results of azimuthal warhead showed that two ignition points mode was more valuable than the three ignition points mode, the fragment velocity curve had increasing trend in 0°~180° radial direction, ignition positions near to the edge of main charge end had the highest performance-cost ratio in the practical application.

Based on the research of maturity model, through the analysis of the system, establishes the enterprise group management maturity model, which including standard of group control maturity level, index system and comprehensive evaluation index. Objectively and quantitatively reflect the level of enterprise management, and help to find the weak link of enterprise group control, so as to formulate corresponding measures for improvement.

There are few literatures, among existing studies, about the fundamental of crop pest image recognition and these literatures are not systematic. In view of this situation, in this paper, the basic content of the recognition of crop pests image were studied. Firstly, two ways of acquiring the pest images have been discussed and compared; Secondly, preprocesses of these images have been studied and experimented, including image graying as well as image enhancement; Finally, seven principles and steps have been proposed to construct the pest image set.

As a large agricultural country, agricultural economic development determines the development of the national economy, and the logistics of agricultural products but restricts agricultural economic development, China's economic development is incompatible with the rural economy, largely agricultural logistics relationship enough disorders due. In this paper, according to the anti-agricultural own characteristics, the condition of the rural economy, the situation of logistics development, management system and development like logistics, be unbalanced urban and rural development and other factors put forward five agricultural logistics development model of sustainable development, and the corresponding development mechanism.

Aiming at the present deficiency of operation examination for marine engine, a simulation system of marine engine based on virtual reality is developed. In this paper, the virtual scene and 3D entity model of marine engine is constructed by 3DS MAX according to the actual situation of engine room and the specific operation requirements, and then the 3D model is driven by DirectX in the environment of Visual C++6.0 to achieve the functions of VR scene roaming, human-computer interaction and operation examination. The VR simulation system developed as a part of the whole marine engine simulator can supply an almost real environment for the crew operation examination, which will greatly improve the operation ability of crew, being of important significance for the reform of crew examination in China.

The hydrochloric acid pickling process which is widely applied in carbon steel pickling ensures high speeds with little pollution. In this research, hydrochloric acid pickling process was introduced into stainless steel pickling to improve the surface integrity. Research indicated that the impedance spectrum obtained from 430SS in HCl solution consisted of a capacitive loop at high frequencies and an inductive loop at low frequencies. As the concentration of hydrochloric acid rose, the radiuses of the capacitive loop decreased.And the corrosion potential of 430SS in hydrochloric acid solution moved to positive direction with band to a narrow 0.1V.And high HCl concentration more markedly influenced the charge-transfer resistance.

The environmental concerns brought during pickling process of stainless steel in HNO3-containing acids need urgent attention. Choosing the hydrochloric acid pickling process as study object, this paper conducted a systematic study of the effect of temperature on the electrochemical behavior of stainless steel in hydrochloric acid solution. Research indicated that as temperature rose, the corrosion potential of 430SS in hydrochloric acid solution moved to positive direction with band to a narrow 0.1V. Meanwhile, the current intensity increased which indicated the acceleration of corrosion rate. In addition, the anode Tafel slope increased firstly and decreased later while the cathode Tafel slope increased slightly.

This paper constructed the technological innovation ability index system of logistics enterprise, propose causation model to evaluate technology innovation ability of modern logistics enterprise, model and solve the causal relationship among the evaluation indexes by structural equation model, The empirical results show that: this model can correctly describe the causal relationship between the indexes, define key indicators of logistics enterprise technology innovation ability accurately, and determine the main influencing factors, provide scientific basis for evaluating and improving the modern logistics enterprise technology innovation ability.

The accelerated gas ions collide with the surface material, the atom or molecule on material surface is removed by momentum transferring. Depositing a layer low viscosity of the thin film materials on the original surface of the optical, such materials will form a layer thin film on the surface of optical element that is lower than the original. Remove the high-spatial frequencies and obtain super precision optical surface.

The appropriate planarization layer is the foundation for realization of ion beam deposition correction polishing technology, the significant difference between ion beam deposition correction polishing technology and ordinary ion beam polishing, is using spin or methods of ion beam sputtering deposition, forming sediments which has planarization effect on the processing surface to reduce intermediate frequency error, coupled with ion beam polishing, removing the high-frequency processing error, the typical error is cut marks by single point diamond turning left on the component surface.

Chinese traditional Yaodong has a long history. Traditional Yaodong is what coexistence with nature and living-practice creating architectural cultural treasures.The sunk-yaodong is underground construction of a unique residential of folk dwelling Sanmenxia in western Henan after a thousand years of culture and experience precipitation. It contains a lot of idea of energy-efficiency and ecology, While its have numerous difficulties in the new modern context. Facing the new era development request, the traditional Yaodong dwellings need to be made the necessary modification. The main way is to through the rational use of solar energy and stereoscopic greening measures. At the same time, not only retained the original advantages, but also improved traditional Sank-Yaodong.

In this paper, three-dimensional finite element model of titanium alloy TC4 was established by using three-dimensional finite simulation software-Deform.Change rule of cutting force and cutting temperature can be obtained in different cutting parameters including cutting speed, feed rate and cutting depth.

This paper introduced a concept of frequency inspection coefficient to find relationship among frequency inspection coefficients of static flexibility, strain and structure dynamic load. Explored this theory resemblance of structure stiffness evaluation which based on frequency inspection coefficient and static flexibility inspection coefficient separately, and verified reliability of this method which aiming at arch bridge via the result of measured static and dynamic test data of sample bridge.

The influence of fuel properties on flame radiation transfer was investigated with numerical method under certain combustor fuel-air ratio and inlet air temperature in a gas turbine combustor. The numerical results show that the fuel properties affected the fuel pulverization quality, evaporation efficiency and combustion efficiency, which caused the flame temperature and its distribution change. Meanwhile, it has an effect on the formation and concentration distribution of soot, resulting in the changes of inner flame radiation heat flux and temperature caused by flame emitting radiation. Furthermore, the gas temperature change caused by the fuel properties more but the hydrogen content effect is relatively small, has an influence on the generation of NO which caused the change of the combustion efficiency.

The combination of high conflict evidence is a research focus in belief function theory, this paper analyzes two major solving strategy of the modifying rule and the modifying evidence body, and proposes a new evidence synthesis method by modifying rule. In allusion to the combination of high conflict evidence and focusing downwards problem, the method constructs new global conflict measurement under the framework of conjunction combination, which can solve the illogicality of of Shafer conflict measurement. Then the paper designs the solution of local redistribution of global conflict, through choosing the reasonable proportion coefficient, which can overcome focusing downwards and synthesis convergence problem together. Compared with other methods, the new method is more effective to solve the combination problem of high conflict evidence, and meet the quasi-association, and has the higher value of application.

In the belief function theory framework, how to measure conflict between evidences is the first step in the combination of conflicting evidences. However, the existing conflict measurement methods have some limitations. Two new methods based on binary function of the combined belief assigned to the emptyset before normalization and the distance betting commitments of beliefs are proposed. Two methods have three advantages. Firstly, they are more suitable for people's intuitive logic reasoning. Secondly, they overcome the operational problem of the existing binary conflict measurement methods. Thirdly, new methods can measure the conflict between any pieces of evidence simultaneously, which can satisfy the interchangeability and combinability. Some illustration results are presented to demonstrate the effectiveness of the improved methods.

The mechanical properties of gas hydrate-bearing sediments are important basic parameters during natural gas hydrate drilling and exploitation. It’s very hard to get and preserve the actual gas hydrate specimens for the measurements of these characteristics. Experimental techniques for mechanical properties of gas hydrate-bearing sediments are essential and unique because of the special high pressure and low temperature conditions for the stability of gas hydrate. Qingdao Institute of Marine Geology has developed an experimental equipment (Chinese National patent No. ZL 2010 2 0253067.3) to study the variation of mechanical properties along with gas hydrate saturation in different sediments. The combination, configuration and advantages of the equipment, as well as some preliminary experimental results were introduced in this article.

Portable wheel loads measure plate is force sensor based on strain measure and it can bear multidimensional force simultaneously. It is able to recognize radial wheel load through decoupling. Signal conditioning of the sensor will affect the measure accuracy. There are many strain-gauges in the plate. So the signal of measure plate will include CM noise, thermal noise and high shift. The signal conditioning aimed at these disadvantages should be high gain, high accuracy, low noise, low shift, high CMRR. Multisim is adopted to analyze the signal conditioning including strain measure amplifying circuit, instrumentation amplifier AD620, operational amplifier OP07. It is turned out to be low linear distortion and is able to satisfy practical application through the experiment.

In order to realize point-light-source and hurdle lamp LED displays system, a kind of LED display screen controller design based on FPGA and STM32 is introduced by this paper. This design can quickly and easily receive display the data from USB, Ethernet and SD card interfaces through the STM32 processor, and use FPGA to realize data transmission throughput big operation of stable display by double RAM Ping-Pong operation This paper gives drive unit timing for TM1809 series LED drive chip as typical case. This design has applied to LED display controller with stability of reading data and excellent performance.

The study describes the characteristic of field seedling vacuum-vibration tray precision seeder, discuses the necessity for horizontal adjustment on the precision seeder. Horizontal adjustment parallel mechanism is designed, DOF and characteristics of parallel mechanism’s moving platform are systematically analysized, proved the mechanism can meet the horizontal adjustment of two-level tilt angle,which provided a theoretical basis for horizontal adjustment of the seeder.

In the background of new economical age, the necessity and inevitability of application of knowing-separating–application method and knowledge-to-production and production-to -platform and package-platform-mode (PPM) is introduced. The relative concepts of PPM are set definition. The characteristics and considerations of PPM are studied. For designing of application system complexity and re-usable knowledge module rarely, the application of PPM on research & development of compressor monitoring and diagnosis and maintenance management system-CMDMMS is probed. The PPM is a reliable idea for designing of complex application system.

Based on the magnetic suspension theory, this paper has proposed a kind of suspension-type jacquard needle driving principle, and designed its 3-dimension model method. By making finite element analysis on suspension-type needles, analyzing the experimental data and designing the structure, we can get the relationship among related parameters under conditions of different permanent-magnet thickness and air gaps, which can provide criteria in theory and application for designing on new needle driving principle, control system and needle.

Through analyzing the pattern data of computerized jacquard knitting wrap machine, comparing the current storages structure and type, this paper introduces a method for Flash file structure of jacquard data. The method takes advantage of ARM chip to achieve the operations for access and modification of Flash, designing a management procedures of jacquard data access from the perspective of increasing the Flash life. The management procedures not only complete read and write operations, but also meet the requirement of jacquard high-speed data transfer.

In computer vision-based Intelligent Transportation Systems (ITS), one of the key techniques is to detect the vehicles accurately. In this paper, we propose a background extraction and vehicle detection method based on histogram in YCbCr color space. By using YCbCr color space, the influence of illumination change and shadows is reduced. To solve the problem with change in background itself, we propose a background update method by using the pixel change count and histogram. Experiment results show that the proposed algorithm can effectively extract and update the background information in complicated urban traffic environment. It also improves the accuracy of vehicle detection.

Uni-axial quasi-static tests at strain rates 10-5, 10-4, 10-3,10-2 and 10-1 s-1 and dynamic compressive tests at strain rates 1679, 2769,5000 and 8200 s-1 have been carried out to study the mechanical behavior for polycarbonate used in the avigation industry. The stress–strain curves of polycarbonate in the strain-rate range from 10-5 to 8200 s-1 have been obtained. The effects of the strain rate on yield phenomenon and rate-dependent mechanical behavior are discussed. A plastic flow law based on the DSGZ rate-temperature-dependent constitutive model was used to describe the mechanical behavior of polycarbonate in the strain-rate range from 10-5 to 103 s-1. The results at the six strain rates are in excellent agreement with the experimental data, which illustrates that the constitutive model can describe the mechanical behavior for polycarbonate at low and high strain rates perfectly.

This study describes the results on the performance of one vehicle air conditioning system. The coefficient of performance, evaporator cooling capacity, compressor power consumption, total mass flow rate, vapor mass flow rate, liquid mass flow rate and oil in circulation, pressures and temperatures of refrigerant at every component (inlets and outlets) are measured and analyzed with the variation of the outside temperatures at the evaporator and condenser, the speed of the compressor, refrigerant charge and oil charge. The systematical experimental results obtained from this real-size test system depict the relations between the above parameters in a vehicle air conditioning system, which constitute a useful source for vehicle air conditioning systems design and analysis. The vapor quality (two-phase flow) measurements realized in this work provide an extremely important tool for diagnosing the system performances.

when the rough set be used to deal with Knowledge representation system, the data in decision table should be expressed in discrete data, if some conditions or decision attribute is continuous value, which should be discrete Before process.Discretization is not specific data processing only by rough set theory , people have conducted extensive research on discretization problem before the rough set theory put forward , and Made a lot of progress ,but the discretization technique is can not be completely in common used in every subject, different areas have their own unique requirements and handling .This paper proposes a discretization algorithm based on regular conditional entropy.

To transform CAD model into virtual assembly model, model transformation was divided into two processes, namely part model transformation and assembly constraint model transformation. With secondary development of SolidWorks system, both part model and assembly constraint model were extracted form SolidWorks model. The OpenFlight database, which is a standard format for virtual reality simulation, was used to represent the hierarchical model of part. Assembly constraint model was expressed by object-oriented hierarchical model in text file. These two models were associated with each other using unique name or number. By loading part files and assembly constraint file, the assembly model was reconstructed in virtual assembly system. The experiment verified that the presented method was effective.

Theoretical analysis and material experiment are employed to study the “single factor” material model. Based on the dislocation theory, an analysis shows that material model is deeply affected by temperature. By the least squares best fit to experimental data, material parameters are found. Experiment curves analysis and material parameters comparison show that the material parameters of “single factor” model of Mo-Cr cast iron are temperature dependent. Using the mathematical mapping between material parameters and temperature, the “single factor” material model of Mo-Cr cast iron is established, which is proven to be right by comparing with experimental measurements. This work provides a useful insight for understanding the material model and helps to develop further finite element simulation of high speed cutting process of Mo-Cr cast iron.

To verify the accessibility and workspace of tool operation in virtual assembly system, this paper presented a tool-part operation method based on force feedback. According to characters of common tool-part operations, standard fastening tools and parts were modeled using features and parameters at initial stage. Then operator was enabled to conduct different kinds of fastening and unfastening operations in virtual assembly system by three steps namely identification, interactive positioning and operation. With feedback force, the operator can feel corresponding motion constraints of tool during virtual fastening and unfastening operation, so the immersion of virtual assembly operation is promoted.