Search

In this paper, nanosteps were fabricated by a new method. This method used the energy of focus imaging of focused ion beam to peel the material surface for fabricating the nanosteps. By changing the number of focus imaging can get different deepness nanosingle-steps. Changing the magnification, the second-step can be fabricated on nanosingle-step. An atomic force microscopy was used to measure the 3D morphology of nanosteps. When the magnification was 25000, the deepness of nanosingle-step was 65.34±3.00 nm and the deepness of the first step of nanodual-step was 56.03 nm. When the magnification was 50000, the deepness of nanosingle-step was 142.28±3.54 nm and the deepness of the second step of nanodual-step was 178.68nm. This means that the redeposition made the deepness of the first step become bigger, that of the second step becomes smaller. Based on comparison and analysis, the relation of the depth, the magnification and the number of the focus imaging were obtained.

The modal analysis was carried out to investigate the proposed improved curvature based finite element method (ICFE) for parallel manipulator with flexible links. The flexible link was discretizatied with ICFE first, and with the proposed rigid-flexible coupling technique, the flexible displacement of the moving platform and passive links was obtained, then through Lagrange equation, the structural model was derived. At last, to investigate the accuracy and efficiency of the ICFE and rigid-flexible coupling technique, modal analysis of ICFE model with different nodes and comparison studies with CFE and the ABAQUS model was carried out.

This work tends to deal with the multi-objective dynamic optimization problem of a three translational degrees of freedom parallel robot. Two global dynamic indices are proposed as the objective functions for the dynamic optimization: the index of dynamic dexterity, the index describing the dynamic fluctuation effects. The length of the linkages and the circumradius of the platforms were chosen as the design variables. A multi-objective optimal design problem, including constrains on the actuating and passive joint angle limits and geometrical interference is then formulated to find the Pareto solutions for the robot in a desired workspace. The Non-dominated Sorting Genetic Algorithm (NSGA-II) is adopted to solve the constrained nonlinear multi-objective optimization problem. The simulation results obtained shows that the robot can achieve better dynamic dexterity and less dynamic fluctuation simultaneously after the optimization.

In the paper, we research on a preparatory electro-hydraulic actuator product, using the simulation software AMESim to research work to analyze the system performance. We research position in closed loop servo actuator system, generally only considered the requirements of the position. While the speed trajectory and precision control did not do high demand. The position of the system by increasing the speed control strategy module, the system meets the requirements of the position. At the same time, we can achieve speeds start-up operation, stable operation and stopped operation of the three phases according to the requirement following a given trajectory; simultaneously can carry out detailed system performance analysis and research. Simulation results show that increasing position speed control strategy module of the system get very good effect. It can realize the speed control system and satisfy the system output displacement and speed steady-state performance and dynamic response.

The test was simulated for the thin-walled cylinder structure of aeroengine stator casing. Based on the software of LMS-TEST, the experiment of the structure with bolted flange joints was successfully completed for the vibration test analysis and the paper completed the testing under different pre-tightening force. Through the analysis of the measured data, the corresponding spectrum and difference value curve were obtained, the research results showed that the nonlinear characteristics of the bolted flange joint was significant influence on the dynamic responses of the structure, the various nonlinear vibration phenomenon and the signal asymmetry were obvious under different pre-tightening force, which was closely related to the state of the bolted pre-tightening force. By the information of the spectrum and acceleration difference curve, the extent of the bolt tightness can be determined, which can provide relevant reference information for the diagnosis of bolted joint status in the aeroengine stator casing.

set of shell is an important process on lithium battery production line. Research is applicable to automatic set of lithium battery shell of an organization, the installed baffle set into the very core of battery shell, do not harm the very core, set into the very core of the exposed aluminum shell of the same length. This article put forward from the aspects of kinematics and dynamics of multiple optimization objectives, work in a given space and a variety of constraint conditions, with the aid of the NSGA - II algorithm to complete set of shell machine structure parameters optimization, experiments show that the casing precision of the equipment, set of shell and the percent of pass is up to 99 above, has a certain practical significance.

K-means is one of the most widely used algorithms for clustering. Ease of implementation, efficiency, simplicity, and empirical success are the main reasons for its popularity. In actual application, there are some defects in traditional k-means, for example, the value of K need to be specified ahead, initial clustering center is a random choice and so on; this influences the performance of the K-means. In order to overcome these obstacles, many variants of K-means algorithm have appeared. We provide a brief overview of k-means, point out existing problems; summarize major improvements in the determination of clusters number, the initialization of the cluster, the similarity measurement, the sensitivity of noise and outliers and so on. Further study directions of K-means are pointed at last.

Experimental study was performed on the hysteretic performance of H-beam to square tubular column connection with diaphragm-through. The main study parameters are the diaphragm thickness and planar dimension. The experiment shows that the bearing capacity and ductility of the connection are sufficient and the strength degradation is stable as well as the stiffness degradation. This kind of connection meets the requirements specified by current seismic design codes.

This paper focuses on a intelligent performance testing system for lithium battery casting. The testing system can automatically cast the lithium battery in order to change its performances when it drops to the ground and suffers a major collision, at the same time, the testing system can test the changing performances. What is more, the paper gives the design project of the automatic casting mechanism and its optimizing method, improving PID controller, and parameters experiment method. The experimental results show that the testing system can successfully and accurately cast the lithium, it meets the technology requirements, furthermore, it can obtain the accurate testing datas

Light Communication is one of the most common means of vessel communication, with merits of simple, easy-to-use, resistance to electromagnetic interference and so on. Compared with other means of vessel communication, the shortcomings of traditional lighting communication are highlighted, for example, it requires specialized training soldiers, and the information transfer rate is too low. In this paper, an automatic light receiver is presented, and an improved image segmentation algorithm in automatic light communication system is investigated. In the end, some conclusions are given to show the effectiveness of automatic light communication system and its particular application for military use.

According to the FLUENT simulation results of the 90°elbow pipe fluid flow condition, the influence of the pressure distribution about the variation of the flow parameters (v、P0 、ρ) and the geometric parameters (R、d、k=R/d、α、β) is analyzed. By using the dimensionless analysis method, on the basis of the influence of the 32 set of parameter variations on the elbow pipe wall pressure distribution regularity, the pressure qualitative function is established including the geometric parameters and the flow parameters. Through the 155 kinds of the FLUENT simulation results, the fitting software 1stOpt is used to verify the internal pressure model above and fit the undetermined coefficients. The verification shows that the model is of a higher calculation precision and the relative error isn’t exceeding 0.003%. It provides a theoretical basis to check the strength of the bend and design the pipeline with high pressure and speed.

Flexible thin-film lithium batteries can power flexible electronic devices and wearable devices. Here we report room-temperature fabrication of flexible batteries with Li/LiPON/LiFe (WO4)2 active layers on polyimide substrates by sequential magnetron sputtering and thermal evaporation. Inorganic solid electrolyte LiPON films were well prepared to achieve lithium ion conductivity of 1.794×10-6 S/cm in the composition of Li2.7P(O0.99N0.11)4. Due to two redox centers of Fe3+ and W6+ in amorphous LiFe (WO4)2 cathode films, large initial specific capacities of 115.5 μAh/(cm2-μm) and 65.4 μAh/(cm2-μm) are achieved in the flat and bending batteries respectively. After 200 cycles, the discharge capacity remains 27.6 μAh/(cm2-μm). Low-temperature fabrication process of flexible batteries insures the use of lightweight and thin polymer substrates instead of high temperature resistant metal and ceramic substrates.

On the premise of the simulation data for the inner fuild passing the elbow pipe by means of software named FLUENT and dimensional analysis, the formula modle of inner surface pressure for elbow pipes came up by analyzing the relationships among the inner surface pressure P ,the fluid outlet pressure P0 ,axial angle α, circular angle β and the degree of curvature k; Depending on the inner surface pressure data simulated under 150 kinds of conditions, the pressure formula was fitted by means of 1stOpt software; The verification results show that the calculated value by the formula matched with the value of simulation by FLUENT software very well, the maximum relative error was 0.004%, and the research conclusion layed the theoretical groundwork for the design of the high pressure and high velocity elbow.

There are some defects in the traditional over-running load hydraulic system, such as velocity control is poor and prone to velocity jitter, etc. In order to improve these weaknesses, the components and work principle of the separate meter in and separate meter out (SMISMO) were introduced and the actuator’s feature were analyzed , the simulation model of hydraulic studied system was built, the factors affecting the stability of the system are discussed in this paper. Simulation and experiment showed that the novel control system possessed higher velocity control precise and good stable characteristics.

Human demand for energy is increasing, non-renewable energy storage on Earth drastic drop in the new energy is in exploring the application stage, humans had to find a way for existing energy saving. LED (Light Emitting Diode) as a fourth-generation light source and its high photoelectric conversion efficiency, environmental protection, long life, the application of many changes and other advantages of the various countries on the national lighting issues[1].This paper explore the cooling area, the material and Presence of heat pipe 's Influence on the heat sink effect. Length of the heat pipe 's affect on heat pipe fin type radiator cooling effect.

The precision of magnetometer positioning is affected by the geomagnetic anomaly, and traditional positioning technology cannot be applied to the motion sensor positioning. A magnetometer localization method based on a variable magnetic source is proposed. The method localizes a magnetic sensor by the absolute value of the magnetic field. Positioning process does not use geomagnetic coordinates to avoid the effects of geomagnetic anomalies. The method uses time-division multiplexing technology to achieve the motion sensor positioning. Simulation results show that the average positioning error is 0.3% and the maximum positioning error is 1.3% when the tilt angle of the magnetic source is ±1 degree. It has the advantages of high precision.

Through this research, the design dynamic similitude relations, model material, model of soil box, loading system, measurement system of "Y" type and numerical simulation of the realization of the dynamic model test, the finite element will be prepared for the shaking table model test study on the mechanical response of ground fissures under strong earthquake.

By using the parametric design language APDL, developed ellipsoidal reticulated shell parametric macros, only enter the long axis S1, short axis S2, high vector F, scale factor t, ring symmetric region shares Kn, radial nodes turns Nx, to generate the desired lattice shell; comparative analysis of 30 kinds of scheme through two types of single-shell ellipsoid reticulated shell with different rise span ratio force, studied its stress characteristics, providing a theoretical reference for designing and engineering ellipsoid reticulated shell application.

The demand for automatic counting of pedestrians at event sites, buildings, or streets has been increased. Existing systems for counting pedestrians in video sequences have a problem that counting accuracy degrades when many pedestrians coexist and occlusion occurs frequently. In this paper, we introduce a method of clustering optical flows extracted from pedestrians in video frames to improve the counting accuracy. The proposed method counts the number of pedestrians by using pre-learned statistics, based on the strong correlation between the number of optical flow clusters and the actual number of pedestrians. Furthermore, we compare the performance of two algorithms that use Harris corner points and lattice points when optical flows are detected. We confirm that the counting accuracy using feature points is higher than that using lattice points especially when the number of occluded pedestrians increases.

With the wind power increasing quickly, its impact on power system becomes greater, thus the dynamic simulation study on grid-connected wind power generators has a significant importance. This paper focuses on introducing the quasi-steady-state approximation method into analyzing the operation characteristics of grid-connected doubly-fed wind power generators. Based on the detailed dynamic model of a variable-speed constant-frequency (VSCF) doubly-fed wind power generator, which consists of wind speed model, the integrated model of wind turbine and drive system, pitch angle control model, converter control model, and the integrated model of generator and converter, the quasi-steady-state approximation method is introduced and applied to simplify the detailed dynamic model to be an order-reduced model, that is, the quasi-steady-state (QSS) model. The accuracy of the QSS model is shown by comparing simulation results of QSS model and the detailed model.

For the public places, statistical analysis of pedestrian traffic can be used for pedestrian flow rate distribution in time and space. The effective analysis personnel density can be used as important data for the improvement of the public places software and hardware facilities. In this paper, we introduce a method based on Pyramid optical flows clustering of corner point to improve the counting accuracy. We also report that using length clustering, angle clustering and original location clustering to enhance the counting accuracy.

This article is based on the idea that considers the influences of uncertainty, constraint programming model based on stochastic programming opportunities, expressed by means of probability constraints, the establishment of a constraint programming model for the optimal opportunity of wind power uncertainty, stochastic simulation technology development program and the particle swarm algorithm is used to solve this model based on IEEE30, at the end of the node optimization and simulation, to verify the feasibility of the model and algorithm. The whole procedure lays a good foundation for improving the situation of large-scale wind power grid dispatching and operation level access.

There have been considerable efforts contributed to the development of effective energy demand forecast models due to its critical role for economic development and environmental protection. This study focused on the adoption of artificial neural network (ANN) and autoregressive integrated moving average (ARIMA) models for energy consumption forecasting in Hong Kong over the period of 1975-2010. Four predictors were considered, including population, GDP, exports, and total visitor arrivals. The results show most ANN models demonstrate acceptable forecast accuracy when single predictor is considered. The best single input model is the case with GDP as predictor. Population and exports are the next proper single inputs. The model with total visitor arrivals as sole predictor does not perform satisfactorily. This indicates that tourism development demonstrates a different pattern from that of energy consumption. In addition, the forecast accuracy of ANN does not improve considerably as the number of predictors increase. Findings imply that with the ANN approach, choosing appropriate predictors is more important than increasing the number of predictors. On the other hand, ARIMA generates forecasts as accurate as some good cases by ANN. Results suggest that ARIMA is not only a parsimonious but effective approach for energy consumption forecasting in Hong Kong.

The performance and wear mechanisms of one type of polycrystalline cubic boron nitride (PCBN) cutting tool with two different cutting edge micro geometries (marked as PCBN 169T and PCBN 169S) have been investigated in this paper. Interrupted turning of round GCr15 steel has been selected as the test method. The experimental results indicate that PCBN 169S has a greater thermal wear resistance than PCBN 169T at high cutting speeds. It is believed that edge preparation can shorten or eliminate the initiative wearing stage, improve the impact resistance, reduce the occurrence of chipping or dilapidation, and extend tool life. Scanning electron microscopy (SEM) were used to evaluate wear mechanisms of PCBN tools. Our results show that the dominant wear mechanisms for PCBN 169T and PCBN 169S are mechanical and chemical wear.

The concept of Units and Grid Coordination (UGC) is introduced. Problems about UGC are drawn from some power interruptions. Some attentive issues are present in excitation selection and design in future power system such as reliable operation of PSS, coordination between excitation limiters and protections, operation mode of excitation control in running stage. Special attention should be paid to the selection of excitation type, parameters design of 1000MW class generator unit in planning stage.

With the rapid development of wind power technology and industry, the structural loads become a limiting factor for safe wind turbine operation and wind turbine operation life. In this paper we present a design of dynamic torsional load control and the design are based on fuzzy control. Simulations are presented to demonstrate the efficiency of our design.

WSCC and IEEE have suggested that PSS should be widely used. In China, many PSS have already been used as the inter-connected grid is getting larger. However, the feasibility of Widely Usage of PSS hasn’t been proved, as PSS may introduce some negative damping. This paper indicates that PSS mainly transfers the damping from non-electromechanical mode to the electromechanical mode. And one generator’s PSS mainly enhances the electromechanical mode’s damping associated tightly with the generator, while introducing very little positive or negative damping to the electromechanical mode associated weakly with the generator. Widely Usage PSS’s positive effect is much more than the negative effect. As a result, Widely Usage of PSS is feasible.

Large disturbance stability of the system was greatly affected by the way of a lot of wind power centralized access to high voltage transmission network. We could use the traditional operation control scheme of controlling the wind farm and the nearby generator system operation output, but the wind farm and conventional power plant's interests would be seriously affected. Therefore, this paper put forward the control strategy by using the combination of low voltage protection and security automatic device. Large disturbance stability level could reach or close to the level before the wind, so as to minimize the impact of wind power integration on large disturbance stability of power system.

Fiber Bragg Grating (FBG) sensing technology is widely used in detection of temperature, strain and etc. Now the application of FBG sensor is limited below 200°C. Application over 200°C is still an engineering challenge since no suitable FBG strain gauge. In this paper, FBG strain gauge structure which consists of three FBGs is designed and fabricated based on the theoretical strain and stress analysis. This strain gauge can be used for the real-time high temperature strain monitoring situation. The elastic high-temperature alloy (10MoWVNb) is chosen as the substrate. The three FBGs with a similar performance are fabricated on the substrate by high-temperature glue. Among the three FBGs, FBG1 is used for the horizontal strain monitoring, FBG2 is used for the longitudinal strain monitoring, and FGB3 is used for high temperature cross-sensitive compensation. The fabricated high temperature FBG gauge is demonstrated suitable for high temperature strain monitoring by experiment.

Based on the analyses of the current solenoid valve driving circuits in marine diesel, a new type of dual-power double-maintain injector driving circuit is designed for marine high-pressure common-rail diesel. The circuit uses BOOST high voltage (80V) and storage battery low voltage (24V) to make up of dual-power time-sharing driver, which achieves automatic PWM feedback modulation of the solenoid valve injection current from the hardware. Experiments were carried out on a certain type of injector, the results showed that: the driving circuit had fast response time, only 0.045ms from zero to 22A of the solenoid valve current was required; the peak value of driving current has a good consistency, parameters including peakvalue current altitude, lasting time, maintain current altitude and maintain current lasting time could be adjusted flexibly. Besides, the circuit could be flexibly configured without occupying MCU resources.

Among all the kinds of optical fiber sensors, FBG and LPFG become the main current owing to its features and advantages. LPFG sensor is especially suitable in high temperature sensing and stimulates more related research interests. The key point of LPFG sensing is the signal demodulation and processing. In this paper, signal demodulation of the LPFG strain sensor was studied based on Arrayed Waveguide Grating. The fabrication method and high temperature performance of this sensor were presented,and a novel strain signal demodulation method was presented based on Arrayed Waveguide Grating (AWG) device by equi-intensity cantilever beam. The experimental results demonstrated that the signal demodulation technology based on AWG has many advantages, such as simple structure, innovative and reliable performance.

In order to develop actuation circuit for high pressure common rail injector solenoid valve, the high and low voltage time-sharing actuation control method based on current feedback was researched. A finite state machine tool called stateflow was used to establish the actuation model of solenoid, and the intelligent actuation control circuit was developed according to the model and MCU. The driving current can be adjusted automatically according to “Peak-High-Low” three-stage current, and the circuit can troubleshoot the state of solenoid. Driving Experiments on solenoid and injector were carried out and the results show the good performance of the intelligent actuation control circuit.

According to the problem of bionic shark gill jet can reduce friction on shark surface, a model of bionic jet surface was established based on shark surface was analyzed by measurements, and its numerical simulation was processed by using RNG k-ε turbulence model. The results show that: the gill jet can reduce frictional resistance on shark surface, and the best drag reduction can be got when the speed of main field is 5m/s, furthermore the maximum drag reduction rate can be up to 17.15%. The pressure of jet hole upstream is reduced which due to the barrier to the facing fluid by the jet, so that the pressure resistance of jet surface is reduced as well. Besides, jet fluid is blocked in the boundary layer by mainstream fluid, which caused the fluid velocity of jet hole downstream is reduced, the thickness of boundary layer is increased, and the normal velocity gradient of wall is reduced, so as to achieve the effect of drag reduction.

In this paper, we present a modified discrete Fourier transform (DFT)-based channel estimator for orthogonal frequency-division multiplexing (OFDM) systems with null carriers. Due to the channel leakage, the conventional DFT-based estimator has the problem of error floor. In order to suppress the leakage, we adopt the optimal leakage suppression method. Moreover, a novel denoising method based on dual-tree complex wavelet is proposed to further improve the performance. Simulation results show that the proposed channel estimator can effectively overcome the performance degradation caused by the leakage and additive-white gaussian noise (AWGN).

Modern control theory has been used to design a variable pitch controller based on disturbance accommodating. The controller realizes the optimal control which minimized the controller action and drive-train torque. A torque controller based on pole clustering had been designed to enhance drive system damping and to suppress torque ripple. The federated control of variable pitch and torque is adopted to reduce drive system dynamic torsional load, and has been verified by software MATLAB and FAST. Simulation result illustrated that drive system dynamic torsional load can be controlled to improve reliability of wind turbine and extend life of critical components by active control method.

The current situation of environmental protection clothes under low-carbon economy era is analyzed, and the design methods of environmental protection clothes are discussed by starting from three elements of clothing design: clothing styles, materials and colors. On the one hand, the damage of clothing production to the environment will be solved; on the other hand, long-term sound development of the industry will be realized. To realize the change of clothing product from the aspect of design, so as to gradually change the production modes, further to make it fit the requirement of environmentalism.

This research studies the causal relationship between energy consumption, gross domestic product (GDP), and foreign direct investment (FDI) in Germany for a period of 1971-2010. The empirical results reveal that there is a unidirectional causality running from GDP to energy consumption and from GDP running to FDI in Germany. This is due to the highly rising trends of economic activities in the country which can lead to the expansion in energy consumption. As there is an increase in economic activities within the country, then the growth rate will be in the rising path. As a result, the foreign investors will see the promising future and then invest in the host country. The conservative energy policy is recommended to support the energy saving because it will have little or no adverse effect on GDP. The energy efficiency should be applied by encouraging the use of renewable energy sources in economic activities as an alternative to stimulate the economic growth of the country. Also, the public expenditure should be expanded to increase the country’s economy and attract foreign investors. In addition, the government should support for the service industry such as insurance, finance and banking, and tourism because this type of industry does not consume as much energy as the manufacturing industry does in the overall manufacturing processes. Besides, the government should provide tax credit for the manufacturers who can fulfill the energy efficiency for their operation.

It studies the impacts of the wind speed disturbance such as the gradient wind and gust on the active power, reactive power and voltage of the system. In the process of wind speed disturbance, double fed wind turbine increases or reduces the reactive output of wind turbine timely according to the changes of system voltage, ensure the machine terminal voltage to operate in the normal range .

Salt and anhydrite formation of Fauqi oilfield in Iraq contains salt, anhydrite and shale. Complex situations have occurred in drilling process, such as overflow and sticking. The cores of the three lithology rock are fetched and their strength and creep mechanical properties are tested. Anhydrite is with higher strength and lower creep properties, and shale and salt is with lower strength and higher creep properties. The collapse pressure and fracture pressure of the three lithology rock are calculated. The safe density window of anhydrite is the most widest and there is no risk of wellbore instability, and the safe density window of shale is the narrowest and wellbore instability easily occur. The low limit of mud density to prevent shale and salt creep are calculated by power law model. The safe drilling density window is determined and successfully applied in drilling field.

Based on the theory of equivalent internal friction angle, the soil layers around the tunnel were equal to cohesionless homogeneous mass in this paper. On the basis of the Terzarghi unconsolidated mass theory, the local soil arching effect of the existing open trench tunnel which was located the side walls load was discussed under the ground asymmetric filling. Furthermore, when the backfill soil appeared the local soil arching effect, the critical embedded depth formula was given. Finally, it is concluded that both the size and distribution of the ground asymmetric filling load have influence on the local soil arching effect of the existing open trench tunnel.

For target tracking of agile digital array, we propose a novel model called alternate array. The model means that total array is divided into vertical subarray at the present moment, and vertical subarray is transformed into horizontal subarray at the next moment, then the subarray comes to the first subarray divisions, and so on. Alternate array gives rise to differences of statistical characters of measurement error. Filtering performance is influenced by the feature of measurement data. In the paper, we come up with a new method based on Kalman filter (KF) to solve the difficulty. The new method merges pre-processing and data fusion thought together. Simulation results demonstrate the validity of the proposed algorithm.

The small structures can directly affect the admissibility of the coal seam, the mining schedule, cost and safety. Seismic attributes extracted from seismic data can be used to identify small structures; However, geophysical methods often have multiple solutions, this will make the results of interpretation become unreliable. In this paper we will use image fusion technology to fuse a variety of seismic attributes, and then make full use of the complementarity of different attributes to reduce the multiple solutions, and make the seismic attributes more accurately in predicting small structures in coalmine.

Cu-14Fe and Cu-17Fe alloys were produced by casting and processed into in situ composites by hot and cold deformation, and intermediate heat treatment. The microstructures were investigated by using a scanning electron microscope and an optical microscope. The electrical conductivity was evaluated by using a digital micro-ohmmeter. The tensile strength was measured by using an electronic tensile-testing machine. The results show that there are similar cast and deformation microstructures in Cu-14Fe and Cu-17Fe. The tensile strength of deformation-processed Cu-17Fe in situ composite is much higher than that of Cu-14Fe, while the conductivity of deformation-processed Cu-17Fe in situ composite is slightly lower than that of Cu-14Fe at the same cold deformation strain. The Cu-17Fe in situ composite produced by using proper thermo-mechanical processing possesses a good combination of tensile strength and electrical conductivity.

This paper describes the development of all-electric injection molding machines, as well as the application of clamping ball screw, and elaborates the significance of researching lubrication of ball screw mechanism. The formula for calculating the minimum film thickness of ball screw is induced according to Hamrock-Dowson formula and contact parameters of ball screw mechanism. Using the parameters for a specific ball screw model calculates the minimum film thickness at the screw and ball contact. The lubrication state of ball screw is discussed. It provides a theoretical basis for the rational of ball screw lubrication and proper use.

The impacts of wind disturbance on voltage regulation and frequency regulation of power system were studied. The opinion that the regulation of power flow on the tie lines between the grids constrains the integrated capacity of wind power was put forward. Based on the real condition of Inner Mongolia power grid, an engineering practical method was put forward to calculate the integrated capacity of wind power under this constraint. The relationship between wind power and spinning reserve and the impacts of other related factors on the capacity of wind power were studied as well. The impact of wind disturbance on voltage stability where the wind farms are located was studied.

Piston forging process is a vital step in the manufacturing of automobile engines. According to the practical piston product in automobile engines, the three-dimensional geometric model of the piston forging is established, and the forging scheme of the aluminum alloy billet and the mold is formulated. Based on the rigid-visco-plastic principle, the finite element numerical simulation for the scheme of piston forging is implemented. The required load of forging equipment and the wear of the mold are obtained by the given temperatures, friction coefficients and forging speeds in their respectively feasible ranges. To facilitate the parametric analysis, simulation data are fitted in curves, which can provide reference for the piston forging and the mold designing in practice.

In order to achieve 600 meters radio frequency communication and 2-10 meters serial cable communication between remote controller and parking heater, the paper designed the hardware of remote controller and vehicle receivers. Select CC1100 as radio frequency chip, select PIC16F914, ATmega16L as remote control and receiver SPI control chip, select CE8301, LM117 as remote control and receiver power supply module. Finally, the circuit diagram of the receiver and remoter are designed.

Wind energy industry in China has developed from the rapid growth into a period of steady growth. This paper analyzes the development status of wind energy industry in China , pointing out the problem in the development of wind energy generation equipment quality needs to be strengthened, digestion and absorption problems of wind energy technology, the defecting in wind energy development planning and approval mechanisms , mode of financing , market segmentation , and climatic factors, giving advices such as the proposing quality standards, broading the financing channels, promoting the sustainable development of countermeasures in place to sustainable development of wind energy.

The heavy metals contents of 29 samples were tested in Nansi Lake which was divided into 5 parts. The heavy metals included Hg, Cd, Cr, Pb, Ni, Cu, Zn and As. The spatial distribution of heavy metals of 5 Lakes region has been received. The pollution of heavy metals was with evaluated with Igeoand RI. The results showed that: Nasi Lake has been polluted by heavy metals in middle level, and As, Hg, Cd and Pb were more serious. The heavy metals pollution of the part in north were more serious than in south, except the As and Cd. Overall, the heavy metals pollution in the north Zhaoyang Lake was the most serious, followed by the Nanyang Lake, Weishan Lake, Dushan Lake and the south Zhaoyang Lake.

Comprehensive research and other methods were applied to advance that the purpose of project management is to improve core competitiveness in this study, and it is as a proposition. It is discussed that core competitiveness should be improved by taking economic efficiency enhancement as the goal, management mode improvement as the main body, management process refining as the premise and staff quality strengthening as the purpose. The core of improving project management level is to improve the literacy of managers, including ideological and political literacy, moral quality literacy, professional and technical literacy and physical and mental literacy. It is concluded that the manager capacity structure should be improved in order to improve the effectiveness of project management. Thereinto, learning ability is a prerequisite; planning ability is a basis; decision-making ability is the key; technical ability is the main body; adaptability is the core; cohesion ability is a guarantee.