Search

The cathode materials of LiFePO4 batteries decreases due to the gradual loss of lithium content during use. In this paper, the spent cathode materials were recycled with a carbon layer coated. The samples were prepared by a high temperature impurity removal procession and a solid phase repairing method. The LiFePO4 material obtained by the regeneration process has a discharge specific capacity of 105.4 mAh/g at 0.1 C after 10 cycles, and keeps it a considerable retention of 73.1 mAh/g at 1 C. This work provides a new routine in reusing lithium ion batteries.

Sediment layer can change the dynamic property of reservoir water. As a result, the dynamic response of dam body would be affected. In this paper, the sediment layer is simulated as saturated liquid-solid two-phase media, and the finite element model of gravity dam-reservoir water-sediment system is established with the gradual enlargement mesh method. Then the influence of sediment layer on seismic wave motion is studied with this model. The calculation result shows that the energy radiation of far field of foundation, reservoir water and sediment can be considered efficiently in this model, and with the thickening of sediment layer the dynamic water pressure on dam face decreases.

For the large air bearing capacity and high rigidity, the author put forward a kind of slit type guide rail which based on gas film clearance throttle,through establishing the guide physical model,fitting the gas film surface ,and building a flotation control equation, refering to the finite difference method and dichotomy,solved the gas film pressure distribution based on Matlab numerical calculation,analysed the bearing capacity of gas floating needle bar under different eccentricity and the stiffness.The results show that: the gas floating guide,if a slit’s width is 0.2 to 0.26,and the cumulative length of the slit for half of the perimeter of the inner surface,the slit intermittently arrange six along circumference,has the best static performance.The larger the needle bar eccentric,the bigger the flotation capacity and stiffness,it is capable of carrying the load of the needle bar,and the air tightness of the structure is good,throttling effect is obvious.

In order to increasing the energy efficiency of Free-piston engine generator (FPEG), an experiment was taken on to study the generating characteristics for it is one of the most impressive factors. The results show that: The aptitude of phase voltage is related with velocity of piston and flux of linear generator, phase difference is 120 degree; the piston is not moving in uniform motion; the velocity around TDC and BTD has obviously different; with the work frequency increase, the output phase voltage is increasing; when the external resistor is equal to interal resistor, the output power reaches it maximum.

Based on Infineon XC167, an electronic control system was designed for internal combustion free piston engine generator (FPEG). The displacement was output in form of 4 channel differential signal by Coaxial magnetic grid, so the signal processing circuit was designed, and the displacement signal can be trapped by single-chip micro-controller; according to the current displacement, the ignition pulse width and ignition position was calculated by the single-chip micro-controller, ignition pulse was output; the operation parameter was monitored and control parameter was adjusted by PC. The test results show that: modular design was introduced in the design of electric control system, and it monitors and controls the FPEG accurately, the control objectives are achieved.

In order to study characteristics of a two-stroke spark ignition free-piston engine generator (FPEG), a dynamic simulation model which derives from several dynamic and thermodynamic equations is built in Matlab/Simulink . Simulation results show that: comparing to conventional engine, FPEG has advantages on efficiency andNOxemission level. By varying the moving mass, the compression ratio will increase accordingly while frequency keeps nearly constant. By varying ignition point, an optimum ignition advance is available in each case. At last, performance of free-piston engine generator under different fuel supply and load is predicted.

To identify parameters of electromagnetic actuators with analytical models, there are problems such as poor model accuracy, multiple physical fields coupling of model, and slow convergence. Based on error sensitivity numerical analysis, a parameter semi-analytical identification method for electromagnetic actuators is proposed. In this article, a diesel engine speed governing electromagnetic actuator is taken as the research object. First, with finite element method, a numerical simulation model of the electromagnetic actuator is established, and sensitivity of main geometrical parameters relative to electromagnetic force is analyzed. Secondly, with theoretical deduction, a difference model of the nominal and measurement electromagnetic force is built, and the electromagnetic actuators geometrical parameter identification formula is gotten. Thirdly, different numerical methods to construct a system error sensitivity matrix are compared, and the compared result is the accuracy of central difference better. Finally, the average static characteristics error of the electromagnetic actuator is reduced from 3.3174 to 1.0182. Therefore, the identification method is verified effective and feasible.

To improve the accuracy of attitude determination and control stabilization when simulating attitude motion of satellites in the space, the finite element model of the platform of 3-DOF spacecraft attitude control simulator was founded. Gravity field of air bearing testbed and formula for platform’s moment of inertia on the action of gravity was induced The result shows platform’s attitude accuracy error exist because of main principal axis of inertia change of direction.on the action of gravity, The more large value it is, the more error is .Error of inertia main axis changes as sine curve with the change of two horizontal Euler angle.

Cutter location without interference is the key question in complicated surface NC machining. Starting with the theory of minimum directed distance, this paper, aiming at the problem of cutter location path without interference in the NC machining, reaches an important conclusion that the nine points optimization algorithm based on change step and change search range can get the global optimal solution. Meanwhile, this algorithm solves the astringency problem in iteration algorithm, and avoids a number of point set calculations in the whole area. Due to its features of fast calculation, simple principal and so on, it turns out to be a very effective method to calculate cutter path in NC machining of complicated curved surface.

Inductance is an important parameter of PMSM due to its direct impact on the dynamic performance, especially on the precise control of the system. In this paper, an improved calculation method for the incremental inductance of motor winding is adopted, and a data processing technique is presented. Nonlinear incremental inductance of the motor winding was tested with the dynamic hysteresis loop method. The validity of the parameters FEM simulation results was confirmed by the measuring method. Accordingly, a mathematical model of nonlinear incremental inductance of SPMSM was built which provides a practical gist to determine uncertainty range of inductance parameter.

An ausform finishing process that integrates heat treatment, rolling finishing and hardening of steel components into single on-line manufacturing operation is discussed in this paper ,with the gear steel 20CrMo which is widely used in auto and precise machine industry as a example .the tooth engagement process is modeled ,and the formulas for calculating deformation are deduced.

The encased concrete composite beams were modeled and calculated using nonlinear finite element method, considering relative slipping of concrete and steel. on that basis, the load-deformation curve and the relative slip distribution of the models between concrete and steel along the longitudinal beam bottom were analyzed. Then the results were compared with existed test data; in addition, numerical simulations in 4 groups with cotters in different separation distances were performed, the deformation feature and relative slip distribution rule of concrete and steel in different shear connection degree were discussed.

"six two building" in ocean university of china has been used over 90 years, which can not meet the requirements for earthquake resistance protection. In order to ensure its safe use, at the same time keeping the original building style, this paper proposes the seismic appraisal method after field detection, structure calculation and appraisal regulation check. Then this paper presents corresponding strengthening suggestion. It can be used for reference in other similar old building.

Based on the existing research results, this paper has primarily researched on numerical simulation analysis of a wall-beam joint in complex stress situation in a shear wall structure, in terms of structural deformation, crack of concrete, stress-strain condition of reinforced concrete, bond-slip state of concrete of the joint. The mature finite element analysis software ANSYS is selected as a platform and the parametric design language APDL is used as the foundation. Analyze the deformation of the joint; the cracks and the development status; the strain and stress of the joint and the bond-slip condition between steel bars and concrete. Some problems existing in the results at such joint calculated by commonly-used structure design software PKPM were found to need extra attention and then the paper put forward some feasible solutions.

The U-section steel-encased concrete composite beams, a new type of composite beams with reasonable and efficient form, are developed from the common steel-concrete composite beams. In this paper, the U-section steel-encased concrete composite beams and common H-section steel composite beams were modelled numerically and analyzed contrastively from the same section height and reasonable cross-section two aspects using the finite element method (FEM) and the better mechanical behavior and economic performance of the new-type steel-encased concrete composite beams are summed up.

When detecting the large objects by infrared thermal method, it is difficult to get a whole panoramic picture. So it needs to stitch some infrared thermography. Image mosaic includes 4 steps, feature detection, feature registration, image transformation and image fusion. This paper studies about an infrared thermograph mosaic algorithm based on the feature point detection and registration, and realizes it in MATLAB.

This paper has primarily studied stress-lag effect for reinforced components by using the finite element method. The mature finite element analysis software ANSYS is selected as the calculation tool and the research object is a brick wall of reinforcing concrete splint. The concrete splints bear most horizontal seismic shear force for the stiffness of the new surface course is high. When seismic action occurs, the concrete splints may be broken before the brick walls. After compared the results of ANSYS and PKPM, the actual bearing capacity value of the concrete splints is smaller than the calculation results of the reinforcement design method by current codes for ignoring the influence of stress-lag effect.

Ag/graphene nanocomposites were prepared by the reduction of silver acetate (CH3COOAg)/graphene oxide with hydrazine gas. The samples were characterized by X-ray diffraction and scanning electron microscopy. The electrocatalytic activities of the synthesized samples for hydrazine and formaldehyde oxidation were also investigated by cyclic voltammetry. The results show that Ag/graphene nanocomposites can be prepared by this novel and simple process. The samples present high electrocatalytic activity for hydrazine and formaldehyde oxidation.

determination of the optimum asphalt content usually associates the Marshall Index with volumetric parameters for hot mix asphalt (HMA). Because unreasonable volumetric parameters may result in the asphalt content being more or less so that performance of HMA are influenced. Therefore in this paper, relationships between volumetric parameters and the Marshall Index were studied for two kinds of gradations, AC25 and AC13, which for each kind of gradation, according to the orthogonal test method, the pass percentages of aggregate between the each sieve size and the usage of asphalt contents were changed to form 50 sets of asphalt mixtures for the Marshall test and the volumetric parameters experiment. The results show that rank of influence significance of volumetric parameters on the Marshall Index is Gmb and VV, then VMA and last VFA. However, for fine aggregate (AC13) asphalt mixtures, as Gmb increases, all the MS and the FL increase. Meanwhile, as VV increases, the MS and the FL of AC25 asphalt mixtures increase, whereas for AC13 asphalt mixtures the MS decreases but the FL increases. So for proportion design of fine aggregate (AC13) asphalt mixtures, the fine aggregate and the asphalt content must be strictly controlled to meet the VV requirement and to avoid asphalt pavements to become over-densified. In addition, with VMA increases, for course aggregate (AC25) asphalt mixtures, MS and FL increase, but for course aggregate (AC13) asphalt mixtures, MS decreases but FL increases. Otherwise, the influence of VFA on MS and FL could be nearly ignored.

In recent years, Infrared thermal imaging technology has been widely used in the detection of construction quality relied on its distinguishing features of non-destruction, non-contact and low cost. But, there are many problems in practice, such as it is difficult to quantify the detection results and determine the best testing time. Aimed to several issues of the infrared-thermography method on detecting the defects of external wall, this paper discusses the determination of the optimum time and puts forward a method which can decide the defects quantitatively; it is the method of temperature rise rate.

This review describes the author's research progress of dispersive-tube structure, summarizes the basic concepts of dispersive-tube structure, the mechanical characteristics of concrete tube, and the wind resistant behavior with the seismic performance. Examples of related studies have shown that, dispersive-tube structure have significant advantages in the structural performance and economic performance.

A novel particle swarm optimization algorithm based on chaos searching has been proposed and introduced to optimize the design of beam pumping unit which takes the minimum peak torque factor on the up stroke as the objective function. The optimization for beam-pumping unit have shown the improved particle swarm optimization based on chaos searching algorithm has both advantage of simplify for implement of original particle swarm optimization and advantage of fast convergence, easy to escape local minima for chaos optimization algorithm. The improved optimization has also provided a new method for the design of complex structure.

Based on seismic analysis of concrete-masonry mixed structure, a new strengthening method will be introduced. In order to find the effective and reasonable reinforcement measures to adjust to the characteristics of the mixed structure, the method of equivalent stiffness should apply to the structure, it can change the original unreasonable force transmission route, and then transform and reinforce the original structure into a quasi-frame-shear wall structure whose force transmission route is similar to frame-shear wall structure. This could be a reference to similar projects.

The low-cycle repeated load tests were conducted for two composite frames, with reinforced concrete column and steel reinforced concrete column, respectively. The performance of the composite frames such as the failure modes, ductility, energy dissipation ability, deformation restored ability, and resistant capacity is analyzed. Experimental results show that good seismic performance can be obtained by appropriate constructional measure which can meet the seismic design requirements. Based on the analysis of test data, the reliability of the beam-to-column connections is validated, and the seismic performance of composite frames is found to be influenced mainly by vertical anti-lateral force component. Besides, the form of steel reinforced concrete column is recommended to improve the structural ductility.

Green cutting is one of the developing tends in the industry field. Water vapor can be introduced in metal cutting as coolant and lubricant due to its pollution-free, generating easily and unneeded disposal. Therefore, a special generating system is developed to produce suitable water vapor, and a simulation to the velocity of water vapor jet flow is presented. Then tool wear was investigated and a new capillary model is proposed, based on the experimental results. According to the boundary-layer theory, the kinetics equations of flow were solute. The velocity and flux of molecule are presented. In the capillary, the adsorption of tool-chip interface results in boundary lubricating film; the conical shape of capillary limits the depth of coolant and lubricant penetrating; and the negative press is the motility for coolant and lubricant penetrating. The study results show water vapor can decrease tool wear about 10% times and 20% comparing to cutting fluids and dry cutting, and water vapor could be a potential solution of green cutting.

This paper introduces a mechanical product intelligent design platform. It presents a product information representation model, gives out the store structure, retrieving process of product cases and the usage of their knowledge for a new design. Finally, it gives an example of product design using this method, proving that it is quite good for product rapid responding design to meet fast changing market requirement and customer’s individual demand.

A large number of specimens with different contents of cement mixed superfine tailings, which took superfine iron tailings as aggregate, were produced to carry out a series of experiments on the mechanical properties of different ages and freeze-thaw cycling tests. The strength, load -deformation curve, frost resistance and other performances of cement mixed superfine tailings were obtained. The experiment data were compared with cement mortar and cement-mixed soil ones under the same conditions. The results are listed as follows: on even ground, the strength of cement-superfine tailings can be 4-6 times higher than that of cement-mixed soil, and about 10% lower than that of cement mortar; the relation of load-deformation and the characteristics of freeze-thaw cycles are basically the same as cement mortar under the same conditions.

Ausform finishing process plastically deforms the surface of a steel component, generates compressive residual stresses in the surface layer, and imparts added strength and durability to the component. It integrates heat treatment, roll finishing and hardening of steel components into a single in-line manufacturing operation. The gear steel 20CrMo is introduced to determine various operation parameter of this process. The experiment results shown that ausform finished gears have the advantages of improved surface finish and profile accuracy.

High resolution DEM(Digital Elevation Model, DEM) is created based on original CAD terrain map (one reservoir as example). Then the article offers precision analysis、topographic factors analysis、visibility analysis、reservoir volume and submerging acreage computing. Then adopting GeoVRML technique is to implement the functions of WebGIS 、visualization and query of computing result、graph data visualization and reservoir region virtual scene roaming etc. The system implements deep administrative levels information diged and long-distance visualization expression. The result shows on the basic high resolution DEM to realize 3-Dimensional Visualization Analyse and calculation functions and compress the spatial data to release these data in the WebGIS(Web Geographical Information System, WebGIS) as well as.

Through the researches and discussions of each constituents of multi-resolution watershed model, the article comes to the conclusion that could apply the LOD(Level of Detail, LOD) technique , the blanking technique and so on to the deletions and replaces of DEM(Digital Elevation Model, DEM) data nodes and the unimportant watershed region in the multi-resolution watershed model, the remote sensing images, the multi-resolution building model, the multi-resolution flood routing model. The method could reduce the data quantity of valley model. The experiment has proved that the multi-resolution watershed model with the applications of this method could not only express three dimensional virtual large scene of the watershed better, but also make the visualization of the mass data model in real-time interactive manner in condition of the computer capability nowadays. This achievement has provided the new thought for the compression of remote sensing images and data transmission of WebGIS in real-time interactive manner.

Based on geological condition of underground factory building in Hohhot pumped storage power station, research and analysis are taken for the fundamental element which affect initial stress field, 3D finite element model of underground factory building is build for the analysis. Beigin with regrssion analysis, adopt linear elasticity caculation of finite element method to take linear regression analysis, and obtain range of optimized parameters. Adopt homogeneous design to definite various assemblies of optimized parameters at different levels. Obtain training sample by elasto plastic caculation of finite element, train for RBF model in oder to get inverse model of ground stress field. The calculation result shown that: RBF model overcome the disadvantages such as slow calculating speed and overfitting of BP model, and it could obtain distrubution rule of initial stress filed by inverse analysis in a reasonable way.

The multi-resolution flooding routing model advanced firstly is composed of the extensive flooding routing model and the fine flooding routing model. In the article to put up research and discuss detailedly the 3D visualization of the mul-resolution flooding routing model which is as the non-engineering measure about the water conservancy management. In the article to analysis the constructing method of the mul-resolution flooding routing model mainly ,which is the theory and method about the extensive flooding routing model and the fine flooding routing model constructed and to work out material the extensive flooding routing model and the fine flooding routing model. Finally to applying the statistic analysis method to get the below conclusion: ①Applying the visualization system about the multi-resolution flooding routing model is to act the non-engineering measure about the water conservancy management and it provides a new thought and trusty scientific decision-making for the water conservancy management department; ② The results of the storage capacity and the submergence area worked out by the the fine flooding routing model are more precision than the result of the general method. The above conclusion proves the feasibility and science about the construction of the multi-resolution flooding routing model adequately.