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Selective laser melting (SLM) are getting more and more established as reliable methods for producing open-porous scaffolds with accurately controlled pore size, strut size, and porosity. However, the optimal geometrical parameter of the unit cell by SLM remained unclear. In this study, we evaluated the effect of unit geometrical parameters to the mechanical properties of porous scaffolds by finite element analysis method and Mechanical testing method. Six rhombic dodecahedron unit cells were designed with different geometrical parameter and the scaffolds manufactured by SLM using Ti6Al4V. The compression testing results show that the specimens with the same pore size, the elastic modulus and the strength are increased with increasing strut size and the specimens with the same strut size, the elastic modulus and the strength are decreased with increasing strut size. The porosity can be calculated by pore size and strut size. The compression strength of the porous scaffolds is 114MPa~258MPa and the quasi-elastic gradient is 3.18Gpa~8.64Gpa, which are similar to human bone. The simulation values are different from the experiment values but the variation tendency is in accordance.

A novel cementitious microfiltration membrane was fabricated for water permeation. The membrane wasproduced using low-cost cement and quartz particles under ambient conditions, rather than a sintering process as was generally applied. By the analysis of SEM, pore size distribution and water permeation tests, the effect of water-to-cement ratio (w/c) on membrane structure was studied. The membranes havebimodal pore size distributions, with varying mean pore sizes of 6.5-8.7 μm. With the increase of w/c from 0.3 to 0.8, membrane pore sizes and porosities show a similar trend of first increase and then decrease. Moreover, membrane structure tends to dense in this process, which results in an obviously decrease ofmembrane water flux from 53 to 1 m3·m-2·h-1·bar-1.

The transient vortex structure evolution process of two-dimensional flow in a driven square cavity with one moving end was studied. The time curves of flow field variables, the flow patterns of different specific moments and the required times of flow field from static to statistical steady state were comparatively analyzed for different Reynolds numbers. Transient simulating results show that the nascent vortices always appear near the boundaries in the initial driving stage, then gradually move away from the boundaries to form a large vortex almost occupying entire cavity and two secondary vortices in left and right corners of the cavity bottom. The greater the Reynolds numbers, the longer the required times of the flow field reaching by the statistical steady state, also, the more complex of the vortex structure evolution.

This paper introduces a new correction method for laser scanner system. Based on image recognition, the laser marking result which includes a crossed matrix is grabbed as matching pattern. A algorithm is presented to locate all crosses and measure their positions , and a correction data is generated automatically for laser scanner system. This method makes the correcting process be much faster and more accurate than conventional manual measurement way.

A system for detecting the conditions of crop disease stress by acoustic emission technology was studied and developed .The PCI-2 acoustic emission board and R15 acoustic emission sensor probes were chosen to construct the hardware detecting system, and the AEWIN software and virtual instrument technology were utilized to construct the software system, a real-time acquisition and detecting system for the information between acoustic emission and disease stress of crop was established. The results show that there are a certain physiological cycle laws in the acoustic emission of healthy crop, generally the “double peak area” can appear; but distortion can occur in the acoustic emission of disease stressed crop, a sharp increase of the acoustic emission frequency can suddenly take place at some time, immediately the crop begins to show disease symptoms, and acoustic emission signals lose the regularity.

The linear adaptive neural network and RBF neural network, according to the measured low-pass filter lateral acceleration signal, was used to establish the reference lateral acceleration applied for the input of tilting train control system. This paper presents the two types of neural network models and prediction algorithms, and studies the time complexity of the two types of network algorithms. The results show that time complexity of the neural network prediction is closely related to its parameters, the neural network structure also can lead to the difference in their calculation time, and RBF prediction neural network spends the minimum time.

The vortex structure of two-dimensional flow in a cavity is calculated using the differential quadrature method. The numerical simulation focuses on investigating the effects of Reynolds number on vortex structure evolution of the flow in a square cavity with two opposite and equal speed moving lids. The streamline patterns and bifurcation diagrams are determined. The numerical results show that the flow in the cavity takes on the streamline pattern of completely symmetric vortex structure when the Reynolds number approaches zero. With the Reynolds number increasing, the sizes and center positions of the sub-vortexes appear to be affected, whereas the saddle point is still located at the cavity center, resulting in a skewed flow pattern in the cavity. It is observed that one large vortex occupies the entire cavity and the shape of the large vortex becomes more circular after a critical value of the Reynolds number is exceeded. If the Reynolds number is increased further, two secondary eddies emerge simultaneously on the upper left corner and the lower right corner near the sidewalls. The center of the large vortex is invariably located at the cavity centre. For different Reynolds numbers, the streamline patterns are symmetric about the cavity center which is always a stagnation point.

This paper investigates a practical implementation of a relay feedback based PID auto-tuning method for CNC servo motor. Firstly, the hardware architecture of the CNC system is introduced and experimental process is presented. And then the critical point information is obtained from steady oscillations of encoder output by Ziegler-Nichols tuning rules. Finally, control experiments that based on default PID parameters and auto-tune PID parameters have been conducted and the results show that system performances, such as velocity responses and position following error have been much improved.

The rail flaw detection vehicle which is according to a city rail system construction features has been developed. This vehicle has been used for more than two years and all aspects of the vehicle performance reaches design requirements. The vehicle can meet the demand for rail flaw detection. This paper has introduced the general layout of this vehicle including main technical parameters, the main structure and the rail flaw detection system. Finally, the strength and dynamics calculation of this vehicle has been performed. The results of the calculation are presented and discussed.

Purposes: This study is to improve the mechanical properties and machinability performance of PHBV. Procedures: PLA/PHBV composites were prepared by dry blend in the melt mixing. The contents of PLA fiber in PHBV matrix are 0, 1, 3, 5, 8 and 10 wt. %. Methods: PLA/PHBV composites were subjected to mechanical property, thermal and morphology evaluation. Results: The results showed the immiscibility of PLA fiber and PHBV matrix. The excellent mechanical properties of the composite (the content of PLA fiber is 8 wt. %) were higher than those of neat PHBV. The micrograph of the fracture surfaces showed that the addition of PLA fiber evidently improved the toughness of PLA/PHBV blends and showed a broad spectrum of PLA fiber diameter (about 200 nm). Conclusions: The improvements were due to the efficient of the PLA fiber as the reinforcement. And the blends showed a significant ductile plastic deformation. The PLA/PHBV blends can be used for a wide range of multifunctional biomedical materials such as the internal fixation of fracture.

The deformation mechanism of surrounding rock during excavation is difficult to stability evaluation for large-span shallow-buried double-arch tunnel. Take Fenghuang mountain tunnel in Suzhou city as an example, the main work and funding are as follow: The measured data in the middle of the tunnel, including settlement on the top of the tunnel and deformation between two lateral walls, were used to calculate mechanical parameters by back analysis method. The obtained parameters were used to calculate the deformation and stress of the main tunnel excavation in the different steps. The rules includes time-space effect during main tunnel excavation, force mechanism of the middle wall and settlement on the ground surface for the surrounding rock in the main tunnel. Finally, the calculated settlement and deformation were compared to the monitoring results. The safety coefficient of surrounding rock for double-arch tunnel was obtained by strength reduction theory.

A 1:10 tank-car 2D fluid simulation model based on the computational fluid dynamics is established, and exchange the data with tank-car vibration model while simulating. In the paper, the 2 dimension fluid-structure coupling tank-car which owns two DOF is simulated, and the affect of fluid sloshing to tank-car longitudinal vibration is analyzed through the coupled vibration experiment. In the simulation and experiment, fluid sloshing increased the tanker longitudinal vibration acceleration amplitude and slowed response time is obtained through analyzing the difference between the different volume of fluid and the relevant solid without sloshing, and the difference of longitudinal vibration between full tank and non-full tank is significant.

As the speed of high-speed train become more and more fast, anti-hunting damper become a must to high-speed train which can increase the critical speed of the train effectively. Now some kind of high-speed train operating at the speed of 300km/h has installed four anti-hunting dampers for every bogie. As the number of anti-hunting dampers increased, the probability of anti-hunting dampers failure is also increased. This paper will increase the critical speed of the high-speed train up to 300km/h by optimal design of wheel profile, which can drop the number of anti-hunting dampers per bogie from four to two meanwhile.

Has been actively studied for vessels monitoring system, but most of that is aligned with the large vessels. In recent years, with the growth of the marine leisure industry, there is a growing demand for vessel monitoring and providing information system of small and medium-sized vessels such as greenleisure vessels. In this background, this paper was designed the remote monitoring system showing through smart terminals in remote data has been transferred from the 60ft green leisure vessels. These system will be able to create a demand for green leisure vessels by interconnecting the integration operated system of the green·leisure vessels.

The dynamic analysis and structural parameters optimization approach based on ADAMS for a parallel platform is presented in this paper. Firstly the parameterized modeling of the parallel platform is performed, which is composed of up and down platform, two linear motors and one support beam. And then the impact of the parameters on the performance of the platform is studied. After that the parallel platform is optimized via the optimization module of the ADAMS. Eventually the conclusions are obtained, which provide the guidance for the mechanical and control design of the parallel platform.

Analyses the mechanisms of dynamic heat transfer in the underground works envelope and the simplified calculation method for heat transfer. With the cooperative function of MATLAB, Simulink and COMSOL, simulates the dynamic variation of the heat load, and validates the simulation results by an experiment.

As the construction of enterprise informatization in the iron and steel industry has increasingly matured, it leads enterprise to accumulate a large number of business data that can not be used effectively. So the enterprise lack of data information for auxiliary decision-making activities. This paper puts forward a construction of the iron and steel industry sales system based on BI. Combining sales information management with decision analysis for integrated solutions can handle daily business, effectively extract and analyze enterprise historical data into useful information which provides decision support for enterprises.

An innovative electronic jacquard cylinder has been developed by combining work principle of conventional jacquard cylinder and advanced electronic technology to save the cost of pattern card, and to dramatically increase production efficiency by shortening the period of preparing new patterns. The paper illustrated the design procedure of the control system and also solved the radiating problem of the electronic jacquard cylinder by analyzing the factors of heating. The feedback from clients showed that after a non-stop running of 24 hours at an ambient temperature of 35°C, the cabinet temperature has never exceeded 48°C, which satisfied the design requirements.

In order to graft β-cyclodextrin onto chitosan fibers as more as possible, amino group of chitosan fibers should be protected by benzaldehyde firstly. Based on the similar structure of chitosan and cellulose fibers, different experimental programs were employed to discuss the possibility of β-cyclodextrin grafted onto chitosan fibers in the similar method. By infrared spectral and UV–visible spectroscopy analysis, the results showed although benzaldehyde could be grafted to chitosan fibers successfully to protect amino group, β-cyclodextrin could not be grafted further.

The mechanical-electrical coupled dynamic model of the tilting train is established in order to study the failure effects of tilting control system. Four kinds of movement of the driving actuator are compared, specifically including: normal tilting, no tilting, insufficient tilting and tilting on the contrary. The results has shown: when the tilting is insufficient or no tilting, the influence to the dynamic is small, the curve-passing speed reduces obviously; when tilting on the contrary, the dynamic performances of front bogie become worse and the curve-passing speed decreases much more.

Retracted article: Contrast experiments on the effect of concentration of the total phosphorus(TP) on treatment efficiency of artificial wetland are carried out through changing TP concentration of influent water into surface flow(SF) and subsurface flow(SSF) wetlands and growing six plants (purple-leaf canna, water onion, water hyacinth, oenanthe javanica, calamus, reed). Treatment efficiencies of SF and SSF wetlands with the six plants varying with TP concentration change are analyzed, and some indexes of purifying function of SF and SSF wetlands with six plants including theoretically optimum treatment concentrations and removal efficiencies, actual optimum treatment concentrations and removal efficiencies, and TP maximum daily treatment loads, are obtained. The experimental results show that, TP removal efficiencies of SF and SSF wetlands with the six plants decrease with the increases of TP concentrations, different plants have different levels of treatment efficiency reduction, and the reduction of removal efficiency of SSF wetland is smaller than that of SF wetland. Removal efficiency of water hyacinth is little changed with the increase of TP concentration, and treatment efficiencies of SF and SSF wetlands decrease by 1.61% and 1.12% respectively. Removal efficiency of Canna is obvious changed, and treatment efficiencies of SF and SSF wetlands decrease by 2.94% and 2.55% respectively. Purple leaf cama had the least changes in the decrease of removal rate, and the table stream processing rate decreased by 17.07%, and subsurface flow by 15.94%. The decrease in the removal rate of reed was clear and its table stream processing rate decreased by 20.86% and wubsurface flow by 18.2%. The actual optimum removal efficiency of SF wetland with water hyacinth is the largest of these SF wetlands’ and reaches 85.2%, and its corresponding maximum daily treatment load of TP is 81g /( d • m2). But the actual optimal removal efficiency of SF wetland with oenanthe javanica is the smallest of these SF wetlands’ and is 76.88%, and its corresponding maximum daily treatment load of TP is 51.84g/( d • m2). The actual optimum removal efficiency of SSF wetland with water hyacinth is also the largest of these SSF wetlands’ and is just 88.31%, and its corresponding maximum daily treatment load of TP is 102.6g/( d • m2). The actual optimum removal efficiency of SSF wetland with cama is the smallest of these SSF wetlands’ and is only 78.32%, and its corresponding maximum daily treatment load is 55.2g/( d • m2).

For the bolts on the experiment table, there are two main kinds of forces, namely, shear force and tensile force. This paper will test these two different forces that the bolts received, verifying their compliance with the service life. Finding out which situation is better by comparing the safety coefficient under the static load and the fatigue life under the fatigue load. And then put forward some reasonable measures for improving to make the bolts meet the fatigue life of the experiment platform.

The kinetics of pumice for decomposition of p-chloronitrobenzene (pCNB) in aqueous solution were investigate. The experiment result indicated that ozonation alone and pumice-catalyzed ozonation of trace pCNB in aqueous solution followed the Pseudo-first-order kinetic model at the reaction temperature of 296 K and the initial pH of 6.86. The rate constant of pumice-catalyzed ozonation increase 149% compared with ozonation alone. In two processes mentioned above, the rate constants of degradation of pCNB were found to decrease with increasing of tert-butyl alcohol. The rate constant of ozonation alone appeared to be decreased 73%, respectively, decreasing 194% in the process of pumice-catalyzed ozonation. Under the conditions of this experiment, ozonation alone and pumice-catalyzed ozonation for degradation of pCNB were primarily oxidized by highly active hydroxyl radicals.

Based on the recursion method of shearing ragidity of soil layer, dynamic torsional impedance of the radial inhomogeneous viscoelastic soil is studied.Under the certain fundamental assumption,combined with displacement basic solution of the plane axial symmetry strain question,the displacement the continuous and boundary of the soil layers, the formula of dynamic torsional impedance of the pile-soil contact surface is deduced.Degenerated into homogeneous viscoelastic model,the model is further confirmed accurate.Finally, the conclusion is obtained:(1) The bigger is G2/G1,the larger the soil body actual stiffness is. The dynamic damping presents the trend of increase;(2)In the area of the radial disturbance soil,as ‘d’increases, the soil body actual stiffness is increasing. When G2/G1 is smaller than 1,the dynamic damping is reducing along with increases of ‘d’,when G2/G1 is bigger than 1,the dynamic damping is increasing along with increases of ‘d’.(3)Actual stiffness and dynamic damping assumes the linear variation along with increasing of material damping.

Yixing Jingyi bridge was a cable stayed bridge with double layer arch tower—the main tower and the vice tower. When the main tower was lifting the pile in the post anchorage foundation only bear compression rather than tension. In this paper, the special design of pile cap was introduced, then the lower pile cap was analyzed by software ABAUQS. Finally, the displacement of the foundation was calculated by considering the effect of pile-soil-cap interaction.

A new elastic disc brake pad device is designed. A mathematical model on railway vehicle elastic disc brake is established compared with the non-elastic brake pad by uni-wheel set braking simulation. The simulation results show that the elastic brake pad could guarantee the vehicle braking performance as same as the non-elastic brake pad. When the friction surface of the brake disc or pad has defects, the elastic brake pad can effectively reduce the vibration of the friction force between the brake pad and the brake disc. It has been proved that the correctness and rationality of the design. A new idea for the design and analysis of the disc brake system is provides.

Based on the three-dimensional wave theory,the coupled torsion vibration of the end bearing pile embedded in viscoelastic soil is researched by using the separation of variables technique. Calculation formulas of the torsional complex stiffness and admittance of pipe pile embedded in viscoelastic soil are obtained and the influence of shear modulus ratio, viscous damping coefficient ratio and the ratio of inner and outer radius on the torsional complex stiffness and admittance of pipe pile are discussed.Finally, the following conclusions are drawn.(1) Shear modulus ratio of soil inside and outside the pile, viscous damping coefficient ratio and the ratio of inner and outer radius have no effect on dynamic damping of pipe pile. The impact of shear modulus ratio of soil inside and outside the pile and the ratio of inner and outer radius on pipe pile in low frequency range is little. With the increase of frequency, the influence is increasing. Viscous damping coefficient ratio does not cause real stiffness of pipe pile. (2) Shear modulus ratio and the ratio of inner and outer radius have a significant influence on the admittance of pipe pile top.The greater shear modulus ratio and the ratio of inner and outer radius, the amplitude of the speed admittance curve of pipe pile top is larger .

Through the external flow analysis of 200 km/h high-speed container flat wagon utilizing SST k- turbulence model, we got the surface pressure distributions, flow field, locomotive resistance, containers resistance and so on. The researches show that pressure drag dominates large resistance of high-speed container flat wagon; the size difference between locomotive and container as well as the gap between vehicles will complex the flow in return increase the total aerodynamic resistance of train; due to the influence of bottom flow, the pressure drag of middle container with bogies is smaller than without, but still large.

This study deals with how to retrieve images using a rearranged chain-code based column vector. The chain-code expresses objects or boundaries of areas in straight chains with fixed direction and length, and encodes the final boundary, which is sensitive to rotated images. This study, therefore, works with chain-codes of eight directions in images and uses differences between values of chain-codes to obtain newly-rearranged chain-codes for image retrieval.