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Through magnetite concrete beam under the action of gravity drop hammer impact dynamic bending test, reasonable testing program was designed to realize the whole process of dynamic test data acquisition, beam load and impulse, time history curves of displacement and force dynamic force - displacement curve and dynamic strain of fracture zone curve. By observing the destruction of the different strain rate，the constitutive relation of dynamic strength changing with the loading rate and input energy was studied. At the same time, the strain rate，the fracture process of different rate of damage and the destruction form need to be found.

Since numerical simulation method came out, it has caused a great importance to tunnel engineers and has been used widely. But it has been restricted in three-dimensional numerical analysis of multi-element and multi-working conditions because the out of memory of personal computer, the high cost of high-performance computer and so on. In view of this, we need to search the low-cost computing devices to solve the large-scale three-dimensional numerical simulation in tunnel engineering. After investigation and study, we have built a Linux-based PC cluster system successfully, and use it to simulate the excavation process of Xiamen Jiaheyuan underground access which is a rectangular shallow buried soft soil tunnel. The simulation results provide a basis for the construction. Linux-based PC cluster system provides a convenient and cheap solution for tunnel engineers in three-dimensional numerical simulation of multi-element and multi-working conditions.

With the means of thermodynamic calculation and alloy smelting, the reaction of Mg-Y-Mishmetal-Zr melt in the process of smelting is studied and the relevant thermodynamic data are obtained. The results show that when rare earth (RE) reacts with MgO to seize the oxygen, Y has the strongest capacity while La has the weakest capacity, and Y is most likely to be burned due to preventing melt oxidation. In the reaction of between RE and covering flux, relative to other elements, Ce is less likely to be burned while Y and La are more likely to be burned. The actual smelting result is consistent with the calculation.

In the background of using SINS technology to the car north finder, how to use FOG SINS in-vehicle vibration environment to obtain accurate initial attitude information is analyzed. Based on two-point north finder algorithm, north finder algorithm and kalman filtering algorithm are combined, and the north finder scheme for FOG SINS based on kalman filtering is studied. Simulation results show that, the scheme can accelerate the estimation of gyro bias and accelerometer bias, and effectively filter out short-term disturbances. This scheme can obtain accurate high-precision attitude information in the disturbance environment.

Multi-axial forging was employed to produce simultaneously ultrafine grain size and weak texture in an Mg-7Gd-5Y-1Nd-0.5Zr alloy. The results indicate that the structure of fine grain size and weak texture could be achieved after two cycles of multi-axial forging, which leads to a substantial mechanical properties improvement. The grain refinement mechanism and texture evolution of Mg-7Gd-5Y-1Nd-0.5Zr alloy during multi-axial forging have been investigated.

The hot deformation behavior of Mg-7Gd-5Y-1Nd-0.5Zr alloy was investigated by compression tests at temperatures of 673 K, 713 K, 753 K, and 793 K and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1, and 1s-1. The stress-strain curves exhibit typical dynamic recrystallization behavior with a single peak stress followed by a gradual fall toward a steady-state stress. The apparent activation energy of deformation and constitutive equations for the alloy were determined through regression analysis for conventional hyperbolic sine equation. The apparent activation energy of DRX and dynamic kinetics model for alloy were determined using the regression analysis for Avrami equation. Optical microscope and electron backscattered diffraction were employed to investigate the microstructure evolution of Mg-7Gd-5Y-1Nd-0.5Zr alloy during hot compression. The results suggested that the grain boundary is the main nucleation sites of dynamic recrystallization, and (0001) basal fiber texture has formed during hot compression.

The effect of online solution and subsequent age heat treatment on microstructure and mechanical properties of die-cast AZ91D +1wt. %RE alloy were researched. The results indicated that online solution heat treatment led to inhibit some β-Mg17Al12 phase precipitation, and remained the Al element in matrix plays a role of solid solution strengthening. The online solution samples were aged at 160°C, 180°Cand 200°C. Microstructure results suggested that age treatment caused some lamellar β-Mg17Al12 phases precipitated near grain boundaries. The tensile properties of samples under air cool, online solution and subsequent age heat treatment were tested, which UTS were 194 MPa, 243 MPa and 244 MPa, and the elongation were 3.67%, 3.97% and 1.6%, respectively. The results indicated that the online solution could enhance the mechanical properties significantly, which the subsequent age heat treatment could not improve.

To maximize the photovoltaic (PV) cell output power, the sun tracking control is applied to keep the sunlight perpendicularly irradiated on the surface of the solar array battery firstly, and then the control strategy of weighting-slope method is proposed to track the maximum power point (MPPT) in the PV system. To verity the effectiveness of the adopted methods, both numerical simulation and experiment are carried out. The results show that the weighting-slope method significantly improved the output power of PV array comparing with perturbation and observation method.

This paper discusses a universal remote controller of household electrical appliances using the touch screen. All the household electrical appliances, such as televisions, air conditionings, drinking fountains, fans and lamps, use only one remote controller. It is convenient for the disabled people to use the household electrical appliances. The remote controller is based on the computer controlling technology and infrared communication technology. The touch screen, microcontroller, infrared emitter and receiver compose the remote controller. The controller could control all the household electrical appliances with self-learning function. Household electrical appliances without remote control could also be controlled remotely by installing the receiving circuit. The remote controller has human friendly interface through the interaction between the hardware and software of the touch screen. The result shows that our remote controller has clarified its effectiveness.

In view of complex and fuzziness of geological adaptive cutterhead selection for earth pressure balance (EPB) shield, a cutterhead selection method based on BP neural network is put forward. Considering the structure characteristics of EPB shield cutterhead, typical cutterhead types are classified and summarized based on cutterhead topology structure and number of spokes. After analyzing the determinants of cutterhead selection, one-to-many mapping relation between cutterhead type and geological parameters is put forward, and then core geologic parameters related to cutterhead selection are concluded. The feasibility of using neural network method to choose the cutterhead type is analyzed, and a BP neural network training model for cutterhead selection is set up and tested in testing sample data. The result shows that the selected cutterhead and the construction cutterhead are basically consistent. The feasibility of this method is proved and it can be theoretical basis for the cutterhead structure design which will improve scientific of cutterhead selection.

In this paper we use AHP mathematical theory, combining with VB6.0 software, and establish preschool children's psychological development model, and design preschool children's psychological development analysis system. In the first part of this paper we introduce the AHP structure, and discuss the principle and process of hierarchical analysis; in the second part, combining with the matrix theory we establish the mathematical model of objective function layer approximation. In order to verify the effectiveness and reliability of model, we use the VB software to do numerical simulation on preschool children's psychological development, and obtain the level nephogram and children's psychological maturity index curve of children's psychological development. It provides technical reference and the theory basis for the effect of preschool physical education on the psychological development of children.

China’s present communication systems in coal mine can not effectively transfer information. Hence, rescue efforts are hard to be carried out in case of coal mine accident. To deal with this problem, a method of mine wireless communication system with low-power dissipation based on Zigbee wireless technology is presented. The paper at first introduces the characteristics and structure of ZigBee protocol, then introduced wireless communication networking mode of ZigBee device in coal mine underground, and gave principle of personnel position of coal mine underground and its realizing process.

The p-S-N curve (p = 50%) of die casting magnesium alloy AZ91D with 1% mischmetal was determined and the fatigue strength corresponding to 3.8 × 105 cycles with 50% probability was 70 MPa. The fatigue fracture surfaces were observed using scanning electron microscopy. The fatigue factures varied with the applied stress and their own defects. The fracture surfaces of some samples loaded lower stress exhibited rubbing mark. The fatigue fracture surface of samples with minor defect possessed the mixed characteristics of quasi-cleavage, tearing ridge, dimple and fatigue striation. Fatigue cracks initiated at gas pores and shrinkage porosity clusters. It were found there was an minor defect size as the site of damage incubation on fracture surface of die casting testing bars which fatigue life was near to the upper bound of fatigue lives.

Combined with the pre-test results, homogenization, plastic deformation, aging and other processes of Mg-7.1Gd-4.6Y-1.3Nd-0.5Zr (EW75) magnesium alloy was studied in engineering tests. The results show that in engineering test the large ingots (Φ500×800~900mm) of the EW75 alloy using two-stage homogenization treatment had perfect homogenization effect and no burnt structure. After multi-directional forging and extruded deformation, the homogenized residual second phase particles were fully broken, and the structure was refined and uniform. The peak aged craft was 230°C×6h, with the aging time increasing, the tensile strength and elongation remained unchanged, showing a strong anti-aging ability. The two-stage homogenization treatment + multi-directional forging + direct extrusion deformation + peak aging treatment was used to prepare a high performance EW75 alloy and at longitudinal direction its ultimate tensile strength, yield strength and elongation were 450MPa, 385MPa, 12.0% respectively.

The behavior evolvement of Mg-7.22Gd-4.84Y-1.26Nd-0.58Zr (EW75) magnesium alloy during the hot deformation process was discussed. The flow stress behavior of magnesium alloy over the strain rate range 0.002s-1to 2s-1and the temperature range 623K to 773K had been researched on Gleeble-1500D hot simulator under the maximum deformation degree 60%. A mathematical model was established to predict the stress-strain curves of this alloy during deformation. The experimental results showed that the stress-strain curves were obviously affected by the strain rates and deformation temperatures. The mathematical model could predict the stress-strain curves when the strain rates were under 0.2-1, but there was significant error in some of stress-strain curves when the strain-rate was 2-1by the reason of deformation temperature rising.

Wenchuan earthquake caused huge losses in rural areas. The subject briefly introduced the earthquake damage characteristics of masonry structures, analyzed the earthquake damage reasons. The main purpose is to propose some measures to improve the seismic capacity of rural buildings in Beijing area. Through two seismic fortification measures, can effectively enhance the integrity of the masonry structure, reduce the seismic response, effectively improve the seismic capacity of the structure.

This paper introduces the function and meaning of permanent refuge cavern construction of coal mine. According to the composition of the permanent refuge cavern system, functions of other subsystems, construction site, daily maintenance and harmonious and unified of each system operation, design and study of the system have been introduced in this paper. Focus on the analysis of the specific characteristics of each subsystem and the contents of each subsystem required quantization, provide the basis for the design and construction of coal mine permanent refuge chamber.

Study has shown that clustering in Wireless Sensor Networks can provide well scalability and robustness. Recently, mobile collector (MC) is exploited to achieve energy saving and reduced latency. In this paper, we propose a mobile data gathering protocol using clustering and controlled mobility techniques. First, we formalize the clustering based approach and its requirement, and then propose a heuristic algorithm aimed at minimizing the number of clusters. After the cluster heads (CHs) are determined, protocol produces MC’s tour along which MC gathers cashed data in CHs in sequence. Simulation analysis shows that the number of CHs is less than other similar schemes and the tour length is shortened, accordingly.

There is a well-known conjecture on independent spanning trees (ISTs) on graphs: For any n-connected graph G with n≥1, there are n ISTs rooted at an arbitrary node on G. It still remains open for n≥5. We propose an integrated algorithm to construct n ISTs rooted at any node similar to 0 or 10n-1 on n-dimensional HCH cube for n≥1 and give the simulations of ISTs on several special BC networks, such as HCH cubes, crossed cubes, Möbius cubes, twisted cubes, etc.

This paper provides structure design of the disaggregation pipe in active dry powder inhaler, to achieve the maximization of active pharmaceutical ingredient diffusing and disaggregating from its carriers, uses computational fluid dynamics method in CFX to simulate the turbulence in the structure, observes airflow velocity, turbulent kinetic energy and shear strain rate to evaluate the effect of diffusion and disaggregation and operate Lagrange particle tracking method in the structure to obtain particles’ superficial velocity, volume fraction and shear stress, providing a theoretical basis for structure design of the disaggregation pipe in active dry powder inhaler.

In the cellular networks, a new adaptive Discontinuous Receiving (DRX) scheme is proposed to improve the power saving. In the traditional DRX, the channel monitoring period is fixed, it will waste some energy to monitor channel when there is no data in a long period of time. In this paper, the support vector machine (SVM) is used for traffic prediction, which can predict the data packets arrival time. Then based on this prediction, the monitoring cycle of the DRX is adaptive with the traffic flow. According to prediction result, the sleep period of the receiver will be extended to avoid unnecessary waking up during the idle time. This traffic-aware DRX scheme can reduce consumed power for channel monitoring. The reduction of monitoring channel depends on the prediction accuracy, which has been verified by the simulation results. The simulation results also show that the proposed scheme is effective for power saving.

Low permeability, low abundance, water-bearing gas reservoirs are widely distributed in China, and their reserves constitute 85% of all kinds of reservoirs in current. It has important realistic meanings to develop them. Determining of reasonable gas well production is the prerequisite to achieving long-term high productivity and stable production. This paper takes Shanggu gas field at Sulige Gas Field for example, respectively from the dynamic data analogy methods, the pressure drop rate statistical methods, gas curve methods, production system nodal analysis methods, and studied the reasonable capacity of the low permeability gas reservoir. Through comprehensive analysis，the comprehensive technical indexes about single well reasonable production was determined.

The simplified calculating model for fiber plasterboards filled with concrete core columns with different spacings was established. The method for calculating the moment-curvature relationship of concrete core column and the force-displacement skeleton curves of shear element was then proposed. The test data of fiber plasterboards filled with concrete core columns with different spacings were analyzed based on this model. The calculated curves agreed well with the experimental ones, which proves that this model has the advantages of clear mechanical conception，simple calculation and relatively good accuracy，and is convenient for calculating integral structure.

The simplified calculating model for concrete-filled gypsum wall panels was established. The method for calculating the moment-curvature relationship of concrete core and the force-displacement skeleton curves of shear element was then proposed. The test data of concrete-filled gypsum wall panels were analyzed based on this model. The calculated curves agreed well with the experimental ones, which proves that this model has the advantages of clear mechanical conception，simple calculation and relatively good accuracy，and is convenient for calculating integral structure.

based on the situation of port security and risk at present, the analytic hierarchy process AHP was adopted in this article, thus an analysis model was established for the security and risk of port from view of the system engineering. In addition, subjection function of factors sets was determined based on fuzzy mathematics, then comparison matrix was also gained. Through fuzzy evaluation, complex evaluation point was obtained respectively for the security and risk of port. The result shows that this method is scientific and rational in port security and risk judgment, and it can offer a decision.

This paper puts forward the normal system for evaluating the port security and risk according to the human-machine-environment theory of system, then using Grey system and AHP designs the specific evaluation model to evaluate the port security and risk .An example is given to show the feasibility of the model.

Surface quality of bearing ball is one of important factors to improve service performance. It is difficult to detect bearing ball surface defects with high precision and low cost by conventional methods. In this paper one new classification method based on optical fiber sensing technology was put forward from the longitudinal section angle. Inspection mechanism of Y-type and coaxial fiber sensor were analyzed, the mathematical models of the two fiber sensors were established and numerical simulations were realized by Matlab software. Influence of optical fiber parameters on light intensity modulation characteristic regulation was studied. Light intensity modulation characteristic experiments were done with specimens of different reflectivity and processing methods. The results show optical fiber sensing technique is an effective method to separate different surface of steel ball with extracting of two parameters displacement and surface reflectivity.

The rock mass with polycrystalline aggregates is common geomaterial in civil and architectural engineering as well as hydraulic and hydro-power engineering. For this kind of geometerials, the study on the joint deformation parameters Kn and Ks and the calculation method are not enough so far. Focusing on the rock mechanics and engineering problems of columnar jointed rock mass related to Baihetan hydropower project, analytical models and numerical method based on 3DEC are employed to study the mechanical parameters. The joint deformation parameters Kn and Ks are back analysis using GRNN and the field data of load-bearing plate tests. The application shows that the calculation results are in good accordance with in-situ test results.

A dynamic constitutive model is suggested based on dynamic triaxial test data of dam materials. Combining with construction of a high core rock-fill dam, several key issues, such as dam seismic response, dam permanent deformation, filter layer anti-liquefaction, dynamic strength of the core wall are analyzed by using 3-D dynamic effective stress analysis method. And some useful conclusions and regularity are obtained in the aspects of seismic response and anti-seismic properties. The analysis method and conclusions could be referred to the analogous engineering.

This paper proposes a new kind of detection method based on CCD to measure geometry sizes and roundness error of chain board of roller chain. Image is collected, and is input into computer, then is processed by a series of steps such as grey level transformation, image smoothness, lower filtration, and threshold value selection, etc. The measurement of the geometric parameters and the roundness error relies on the image contour. Roundness error is evaluated by Minimum Region Law. The diameter of the holes and the distance between the axes of two holes are calculated and measured by self-developed program. Roundness error of chain board is less than 8μm, and the distance error between the axes of two holes is 9μm. The diameters of the holes are 4.467mm and 4.461mm respectively. The reasons of measurement error are also analyzed. Theory analyses and experiment show that it is feasible to measure the geometric sizes and roundness error of roller chain by this method, which is both efficient and practicable.

To recognize whether there exist crack damages in the inner structure of aircraft engine based on the borescope images, a method is presented by estimating the coarse feature of edges extracted from borescope images. The method first decomposes an edge into the approximation and details using wavelet transform at all of the possible scales. For the coefficients of the wavelet transform, the logarithm entropy is presented to represent the respective strength of the approximation and details, and the ratio of the two logarithm entropies is defined as coarseness factor. The coarseness factor can be used to estimate the coarseness of an edge. The greater the coarseness factor is, the coarser the edge is. Experiment results show that using coarseness factor as recognition feature of borescope images, the crack damages of the inner structure of aircraft engine can be recognized successfully.