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An ultrasonic Rayleigh wave transducer was designed for nondestructive pressure measurement in vessels. Using polyimide resin as the wedge material, the Rayleigh wave transducer had two piezoelectric elements which were placed in the same wedge with a certain distance. Variations in pressure and temperature of vessels can affect the velocity of ultrasonic waves, which will affect variations in time delay in receiving of the same Rayleigh wave with the two piezoelectric elements of the designed transducer. Based on the acoustoelasticity principle and considered the effect of temperature, a practical correlation model between the time delay and both the pressure and temperature of vessels was developed. Using an air vessel as a specimen, Rayleigh wave transducers were arranged in the axial direction of the vessel. The results of temperature experiments show that effect of changes in temperature on time delay agree with the theoretical results. With the calculation temperature compensation in pressure experiment, the relationship between the variations in the time delay caused by changes of pressure and the pressure is established. The pressure measurement results show that the measurement model is effective and the maximum absolute error is 0.09 MPa, which could be acceptable in engineering application.

Using BP neural network method, we calculate and analyze the molecular structure of aromatic hydrocarbons. Then, we get the electrotopological state indices and the molecular electronegativity distance vectors of 25 aromatic hydrocarbons based on the calculation of molecular structure characteristics and adjacency matrix. By regression, we get and optimize the structural parametersE9,E13,E17andM15. The four structural parameters are used as the input variables and a 4-2-1 network structure is employed to construct a BP artificial neural network model for predicting acute toxicitypEC50. The total correlation coefficientRis 0.994 and the average error between the predicted value and experimental value ofpEC50is 0.079, which indicate that the ANN model has good stability and superior predictive ability. The results show that there is a good nonlinear correlation between acute toxicitypEC50and the four structural parameters. The results of our research reveal that the toxicity of aromatic hydrocarbons is closely affected by electrotopological state indices and the molecular electronegativity distance vectors. Therefore, it will be helpful in assessing the hazard of aromatic hydrocarbons to environment.

The Traditional Chinese Medicine (TCM) industry is a traditional industry of China. A unique, comprehensive and systematic theory and method of diagnosis and treatment has been formed over thousands of years. A large amount of TCM literature and database resources need to be shared via the Internet for queries by professionals and A unique TCM-industry search engine has been developed to comply with such requirements. A new method for generating query recommendations according to the enquiry is proposed based on features of the TCM industry, on the authors’ experience and on learning from the enactment and development of the vertical search engine of the TCM industry. Different from methods used by other search engines such as Google, Yahoo or Baidu, the new method combines the features of the TCM-industry search engine and the Chinese word segmentation of the TCM industry. It uses algorithms to calculate the correlation between query recommendations and stores these in relationship database. Practice indicates that such a method generates accurate and industry-specific query recommendations promptly.It therefore has innovation and promotional value.

The magnetic flux leakage (MFL) testing, as a modern nondestructive testing technology, requires fast and accurate signal progressing methods. A practical signal progressing method for MFL testing was presented, especially for tank floor MFL testing. According to the FFT result of the original signal, a difference amplifier and a low-pass filter were designed in the hardware signal progressing. In the digital signal progressing, a numerical differential progress and an IIR band-pass filter were adopted. Experimental results show that the presented method could effectively eliminate noise. Defect depth measuring results show that, for the 8 mm thickness specimen, the maximum absolute error of depth is 0.23 mm, which means 2.8 % of the 8 mm thickness.

In this paper, a mode conversion model is proposed to increase the capacity of optical fiber communication systems. In this model, a spatial spectral matching method is used to convert the original mode to the desired mode for mode division multiplexing in optical fibers. A binary phase spatial light modulator is employed on the Fourier plane as a spatial filter. Numerical results show that the original modes can be converted to the desired modes.

In order to solve reliability-based optimization design of composite transmission shaft, the parametric finite element model of composite transmission shaft was built by secondary development of ABAQUS. The reliability analysis of composite transmission shaft was carried out with the first order reliability method (FORM). Using python language, the finite element program and reliability analysis program are combined. The reliability-based optimization model of composite transmission shaft was obtained. The feasibility and effectiveness of the optimization model was verified by the results of an example application.

Presently, most of the researches on Map Matching focus on high sampling rate and accurate GPS points. This paper discusses a challenging problem with low GPS sampling rate and some continuous points with large deviation. To solve the problem efficiently, a novel matching method named F&PT is proposed. Firstly we employ a new method to generate sets of candidate roads. The GPS error analysis based on points is translated into based on roads. Secondly, a local strategy based on potential real trajectories is applied to solve the core problem of selecting an optimal road from the sets which contain only two candidate roads. In this approach, we consider not only the spatial location information and orientation angle information but also the influence of local points on the matching point from a new sight. We evaluate our method based on a real trajectory dataset. The experiments show that the proposed method has a higher accuracy compared with the related methods, e.g. ST-matching algorithm and IVMM algorithm, when the sampling interval is less than 210s.

To enhance the ability of the standard Particle Swarm Optimization (PSO) on solving the complex nonlinear problems, an improved algorithm with independent inertia weight for each particle was proposed in this paper. Firstly, a single particle of the particle swarm was studied. The law of the instantaneous movement of single particle at each iteration was analyzed in a novel geometric view. Two importance conclusions were drawn: 1) The introduction of the two random numbers makes the particle search in a broad parallelogram area, while the product of the inertia weight and the particles present speed is the parallel shift of the aforementioned parallelogram area; 2) The search ability will be greatly reduced as soon as a particle becomes the Global Optimal Particle (GOP). Then, on the ground of the significant conclusions, the improvement plan of the standard PSO was put forward. Experiments show that the proposed algorithm has obvious superiority on the convergence ratio, the convergence speed and the convergence stability.

To enhance anti-erosion property of artillery barrel and prolong the using period of the artillery, some new technologies are summarized and discussed in this paper, which including electric explosion spraying technology, hypersonic flame spraying technology and plasma surfacing. The experimental results show that the electric explosion spraying technology is a feasible method to prepare coating for the anti-erosion property of 100mm diameter artillery barrel.

On the basis of processing the PCrNi3MoVA steel with cryogenic treatment and then experimenting with the static tensile and impulse at room temperature, the effects of cryogenic treatment on macro-mechanical properties of the material is studied. The test results show that tensile mechanical property of PCrNi3MoVA steel can be improved with appropriate number of cryogenic treatment, otherwise can be weakened if the number is inappropriate; at the same time, there is no influence of cryogenic treatment on impact toughness of the material

Smart power utilization district is an important constituent of smart grid. Owing to the quantitative and complex of intelligent services, the network for smart power utilization is very complex, and it is very difficult to maintain the network by traditional processes and methods. We construct a network maintenance system focusing on customer service. The core process and module design of the system are based-on ITIL. We design its software system with MVC architecture style, and implement is with J2EE technology. To monitor network flow and devices, we apply network probes to monitor network flow, and apply internet of things technology to monitor the network devices.

The mechanical model of a new spring locking mechanism was established. The optimum spring parameters of the locking mechanism which meet the design requirements were provided by optimization. Using the finite element method, numerical simulation of working process of the locking mechanism was carried out. The rationality of optimization result was verified by simulation results of numerical simulation.

In this paper, by using nonlinear dynamical theory and Arbitrary Lagrange Eulerian (ALE) algorithm in LS-DYNA 3D finite element program, a method of numerical simulation is used to study dynamical response of buried gas pipeline underground shock wave of underground explosion. The simulation results shows that it is feasible for the numerical simulation method in this paper to study dynamical response of buried pipelines underground shock waves from explosion. the conclusion in this paper may provide significant reference for the risk evaluation and disaster prevention of buried gas pipeline.

In order to improve the quality of blind image restoration, we propose an algorithm which combines Non-negativity and Support constraint Recursive Inverse Filtering (NAS-RIF) and adaptive total variation regularization. In the proposed algorithm, the total variation regularization constraint term is added in the NAS-RIF algorithm cost function. The majorization-minimization approach and conjugate gradient iterative algorithm are adopted to improve the convergence speed. We do the simulation experiments for the blurred classic test image which is added additive random noise. Experimental results show that the restoration effect of our algorithm is better than the spatially adaptive Tikhonov regularization method and the NAS-RIF spatially adaptive regularization algorithm, while the value of improvement of signal to noise ratio (ISNR) has improved.

Influence of replacement ratio and water-cement ratio on the recycled concrete mechanical properties were analyzed by testing the compressive strength and tensile strength of the recycled concrete. Results show that the mechanical properties of recycled concrete, compared with common concrete, can meet the requirements of the project. Water-cement ratio has great influence on compressive strength and tensile strength, replacement ratio has obvious influence on compressive strength but little on tensile.

The small variations of components parameters often lead to severe performance degradation in Filtered Analog Circuits (FAC). Most of the researches on soft fault diagnosis in analog circuit are focused on the variations beyond 30% of the nominal parameter in recent years, which is usually unacceptable in FAC. To diagnose the soft fault of small deviation as earlier as possible, the Hidden Markov Model (HMM) was introduced to monitor the FAC. Different from the existing diagnosis approaches based on HMM, in which the variations of components parameters were considered to be random, the continuous variations of the fault component parameter are discretized and modeled by the hidden states of the proposed HMM method. The experiment demonstrates that the proposed HMM approach can model the FAC effectively and recognize the incipient fault earlier.

A machine vision system is developed to detect the cable surface damage of cable-stayed bridge. In the system, four cameras are employed to acquire images around the cable surface. So the same one defect may be split into several images. Image mosaic had to be done to obtain a complete defect image for further process. The feature of cable surface image is simple and its illumination is heterogeneous. So the Scale Invariant Feature Transform (SIFT) feature matching algorithm is suitable for the image mosaic. Firstly, cable surface images should be preprocessed. Secondly, the SIFT algorithm achieves the detection, extraction, description and matching of feature points for defect images. Finally, image fusion is implemented to acquire the integrated image and a complete defect will be showed in the image. Experimental results show that using SIFT for the cable defect image mosaic has good effect on improving the detection accuracy and integrity for cable surface defects.

Now the non-equilibrium MD simulations are frequently used to study the gas flow characteristic at nanoscale. In the non-equilibrium MD simulations, one force which is several magnitude orders larger than the actual force was added on all gas molecules. Its very necessary to study whether such large force added in non-equilibrium MD simulation will affect the simulation results. The present paper carried out the comparative studies on the simulation results of gas flow in nanopores by non-equilibrium and equilibrium MD. The gas number density profile and the gas molecular mean free path are studied in this paper, our simulation results indicate that both non-equilibrium and equilibrium MD produce no obvious difference on simulation results of the gas number density profile and the gas molecular mean free path. It could be concluded that even the force added on every gas molecules is very large in non-equilibrium MD simulation; the added force doesnt obviously affect the simulation results.

The paper proposes two application modes which are Services request model and services provided - request mode in the pervasive environment. The detail architecture of manufacturing Grid based on services provided - request mode is presented and analyzed.

Three-dimensional visual scanning is an advanced non-contact measurement approach that can obtain a complete surface model of object. But, in the method, the local raster point cloud sets calculated must be registered to a whole. To reduce fluctuating errors and increase efficiency, we propose a new method that scanner can be moved around object guided by pre-planning trajectory of the robot. First, considering the structural parameters of the robot, the Inverse Kinematics Problem of each joint rotating function is derived, and the moving trajectory is simulated. Then, the relationship between the distances of controlled motion and data gotten by scanner is analyzed, a transform matrix which registered the local point cloud sets is deduced, the raster data can be normalized to the world coordinate by it. The experimental results show that error of registration is less than 0.09mm. The method is suited to measuring different targets in robot workspace. It can improve the efficiency and flexibility of visual measurement system.

This paper studied how to identify the cashmere and wool fibers by scale density. The scale density is extracted in frequency domain. The theory of extracting scale density and image preprocessing are given in this paper. The samples are 100 cashmere images and 100 wool images. The recognition rate is above 83% by SVM cross validation. The result reveals that scale density is a valid feature in identifying the cashmere and wool fiber.

Very large volume of mined ore materials are processed annually to obtain the various types of minerals that are essential to industrial processes, the upstream tailings dam is usually constructed to store these wastes. But with the increasing of dam quantities, the tailings dam collapsing in flood which are among the most dangerous hazards that affect mountainous and rural areas in a wide range of environments become more and more. Therefore it’s necessary to analyze the collapse mode of upstream tailings dam in flood situation. This paper using the physical model experiment and numerical simulation methods to research on the displacement, saturation line, stress and the broken processes, and the collapse mode of upstream tailings dam in flood water encountered in 100 years are explored. The results have very important significance and scientific support to understand the mechanism of collapse and broken mode deeply, and which have any new exploration for the prevention and control in flood hazard.

The Wenchuan Earthquake of 8.0 magnitude at Richter scale hit large region of Sichuan, China on May 12, 2008. It was a terrible disaster that caused great casualties and serious damages, and largely destroyed natural mountainous ecosystems in the earthquake-hit areas. Since the restoration of those damaged mountainous ecosystems plays an important role in ecological security in this region, it is argued that the reconstruction of those earthquake-damaged ecosystems should be given greater attention before and during the ecological recovery process. Yet, to date, little effort has been made to review and summarize the major unresolved questions relating to the ecosystem recovery after the earthquake. Focusing on the priorities for future research in this subject, based on the study and comparison of literatures we identified and examined four important research questions that need to be addressed, even two years after the earthquake. All these questions need to be resolved before significant progress can be made in habilitating the damaged natural ecosystems, and perhaps more importantly, the results provide very useful information for cost-effective restoration decision making and policy planning for the earthquake-hit areas.

Compressive strengths of recycled aggregate concrete(RAC) with different recycled aggregates(RA) replacement ratios at 7d, 28d, 60d ages are investigated respectively. Failure process and failure mode of RAC are analyzed, influences on compressive strength with same mix ratio and different RA replacement ratios are analyzed, and the reason is investigated in this paper. The experimental results indicate that compressive strength of recycled concrete at 28d age can reach the standard generally, it is feasible to mix concrete with recycled aggregates, compressive strength with 50% replacement ratio is relatively high.

The tribological performance of pure polyamide 66 (PA66) and Carbon fibre (CF) reinforced PA66 composite were studied at dry sliding and oil lubricated conditions. The results show that the coefficient of friction and specific wear rates for pure PA66 and CF/PA66 composite slightly in increase with the increase in applied pressure values. On the other hand the coefficient of friction is in decrease while the specific wear is in increase with the increase in sliding speed values.

The effects of Carbon fiber content and wear condition on the tribological properties of the composites were measured using a block on ring wear tester. The worn surface was investigated with a scanning electronic microscope and the wear mechanism was proposed. It was found that Carbon fiber improved the wear resistance of monomer casting polyamide 6 with the optimal content of Carbon being approximately 5 vol.%. The wear of PA6/Carbon fiber composite was lower than that of the PA6 and increased slowly while its friction coefficient decreased gradually with load. However, the friction coefficient of the composite was somewhat larger than that of monomer casting polyamide 6.

Microwave treatment is a newly developed technique to expel resin from pine wood by generating high internal steam pressure. To understand the mechanism of deresination process during the treatment, a mathematical model was developed and was used to predict its critical conditions. The model indicated that the critical pressure inside Masson pine wood was 1.17×105Pa and its corresponding critical temperature was 104 °C in order to expel the resin mixture from the interior to the surfaces. The experiment results showed that during microwave deresination large quantities of the resin overflowed to the wood surfaces when the temperature of the pine wood was controlled in the range 104-112°C. The result observed during the microwave treatment matched well with the critical temperature predicted from the simple mathematical model. The validated model could provide some understanding and improvement of microwave deresination process.

In this paper, a numerical algorithm for computing grazing bifurcation of periodic orbit in autonomous planar systems is derived and analyzed. We propose an analytical condition which to ensure the orbit quadratically intersects the switching manifold. Based upon this, we take into a new phase condition which ensure there is a branch of periodic orbits. The nondegenerate condition with respect to its bifurcation parameter is presented to ensure the defining equation well posed. A numerical simulation is carried out for the bifurcation diagram of the van der pol system, which agrees with analytical results very well.