Abstract:It is difficult to obtain the globe optimum solution by applying conventional sizing and geometrical optimization methods. Evolutionary topology optimization is conducted for the lower stable of a hydraulic press using a bidirectional evolutionary structure optimization (BESO) method based on ratio of stress changes, and the evolutionary history and index are analyzed. The presented algorithm obtains the simultaneous optimization on both geometry and topology, and a new topology of the lower stable of the press is evolved which possesses a reasonable topological structure. The results of finite element analysis show that the new structure has decreased maximum stress, uniform stress distribution and good material usage.

Abstract:In order to ascertain the numbers of the electrodes (treatment for the sewage) and forecast the grainsize property of the cracked mineral, based on the hypothesis of the equivalent effective volumes of one discharge of electrohydraulic power impulse technology, the formulas are worked out for computing the effective working areas of the two common working modes. The theoretic analysis and the results of the experiments of the treatment of bacillus coil liquid and crushing of quartz ceramic show that the results conform to the formulas relatively, and the precision of the calculated data has relations with the polluted degree of the sewage, the intensity, elasticity and dimension of the solid material, and the formulas for computing the effective working areas are feasible.

Abstract:The differences of the wind field model between wind turbines and common architectures are investigated. It is indicated that substantial frequency contents are transferred to rotor rotation frequency and its harmonics due to the periodic motions of blade. According to standard von Karman power spectral density (PSD) model and rotationally sampled PSD model, the PSD matrix for turbulence on blades of wind turbine is setup. The longitudinal turbulence’s time serials is simulated based on the superimposition of harmonic waves.

Abstract:Electromechanical coupling effect is considered in the dynamic analysis on permanent magnet AC servo precision derive system. Using electromechanical energy conversion and according to the global coupling analysis and the local coupling analysis, the relation diagrams of global electromechanical coupling and local electromechanical coupling between the permanent magnet synchronous motorprecision transmission subsystem are established. Applying LagrangeMaxwell equation, a physical model and a mathematic model of the subsystem are built up, the dynamic equations of the subsystem were derived, and the mathematic model is analyzed. The results show that the mathematic model is correct which provides theoretical basis for experimental study.

Abstract:In order to analyze the discharge features of different insulation defects in various experimental conditions, according to characteristics of partial discharge (PD) from the insulation defects in gas insulated switchgear (GIS)) and using ultra high frequency (UHF) method, a lot of PD experiments are carried out based on the designed four typical physical models of insulation defects of GIS in the simulation device, and the real samples of UHF PD waveforms are recorded. The features of UHF PD waveforms in the different situations are discussed and analyzed in detail, which include different sizes or positions of the physical models or under the different voltages and so on. The results show that in low voltage, regardless of types of UHF electromagnetic wave excited by PD sources, the shapes of PD waveform changed little before the changes of waveform. The remaining time is about several nanoseconds.

Abstract:In order to resolve the hazard of biofouling and scale in circulating cooling water system of power stations, this paper takes the lead in combining highvoltage pulses and highfrequency pulses for sterilization and descaling process. It analyzes both electromagnetic effects and biochemical effects on sterilizing and descaling process caused by the highvoltage pulses and highfrequency pulses respectively. The pulse generator is designed according to the requirements of electromagnetic parameters for effective operation. The design and improvement of process chambers are assisted by electromagnetic field simulation technology. Experimental data prove that the system can output highvoltage pulse whose maximum peak value reaches 7 kV and highfrequency pulse whose maximum peak value reaches 100 V the frequency ranges from 500 kHz to 2 MHz. The rate of sterilization can be as high as 91,and the rate of descaling reaches 71. This system is expected to achieve the standards of industrial water treatment through further research.

Abstract:The propagation characteristics of the partial discharge’s ultrasonic signal in the stator of generator and the difference between the ultrasonic signal and the running background noise are analyzed with experiments. Ultrasonic online location for partial discharge is proven to be feasible. For nonblind area monitoring, the stator is divided into several equal parts. Locating equations are established with electroacoustic detection method and optimized with genetic algorithm. The simulation results indicate that the proposed method of ultrasonic online location for the partial discharge in the stator of generator is correct.

Abstract:The multiphase flow driven by the capillary pressure in the anode flow field of a micro direct methanol fuel cell (μDMFC) is modeled based on the porous media theory. The electrochemical reaction at the anode is taken into account in this model. Parametric studies of the channel size and the power density are carried out to assess the effects on the transport characteristics of the multiphase flow driven by the capillary pressure in micro channels. In addition, the effects of the channel size on the cell performance are discussed. The results show that the liquid saturation in micro channels increases with the increase of the width and height of the channel, but decreases with the increase of the channel pitch and the power density. The cell performance is improved with the increase of the channel width and height. A larger channel pitch and length lead to a lower power density.

Abstract:In order to study the effects of different catalytic walls on combustion characteristics, the premixed catalytic combustion characteristics of methane/air in microcombustor are studied. It lays the foundation for the combustion technology of hydrocarbonfuel in microengine. Numerical simulation of flow and catalytic combustion in microcombustor was done by using laminar finiterate and secondorder upwind discretization methods. The results show that when wall temperature，CH4/O2 mole ratio and methane mass flow rate change, the influence of lower catalytic wall on the methane catalytic combustion efficiency is biggest, followed by side catalytic wall, the smallest is upper catalytic wall. The methane catalytic combustion efficiency unit area of lower catalytic wall is about three times of that of upper catalytic wall. The utilization of catalyst on lower catalytic wall is maximal . Therefore, when coating catalyst, the quantity of katalyst on lower catalytic wall should be appropriate more, moderate on the side catalytic wall, as little as possible on the upper catalytic wall. The influence disciplinarian and contribution rate of different catalytic wall on methane combustion have been gained. The optimized strategy of catalyst coating was put forward and reduced the cost of catalytic combustion.

Abstract:This paper conducts the experimental study on the natural convection characteristics of cold water near the maximum density in horizontal annulus with the fixed inner radius ri=14 mm and different width l=6~18 mm. The temperature at outer wall is maintained at 0 ℃, and the temperature differences between the inner and outer walls range from 2 to 24 ℃. The results show that the heat transfer coefficient at inner wall increases with the increase of the annulus width. When the temperature difference is bellow 4 ℃ or above 8 ℃, the heat transfer coefficient increases with the increase of the temperature difference. When the temperature difference is between 4 ℃ and 8 ℃, it decreases with the increase of the temperature difference. The formula of heat transfer at inner walls is obtained by using the method of linear regression.

Abstract:The wet limestonegypsum flue gas desulphurization system for 660 MW units of a thermal power plant is taken as the object, based on the study of the mass transfer between the gas phase and the liquid phase、chemical reaction mechanism in desulphurization tower and reasonable simplified hypothesis, the turbulent mathematical model of the spray type tower is developed by the methods of concentration of parameters and module modeling. The model is validated by the test of stable state and the turbulent experiments, which can be used as the basis for developing the real training simulation model of the desulphurization system.

Abstract:The deep buried large tunnel, which is complicated in the geologic condition. The unplanned construction often causes accidents, such as water flush, mud inrush, collapse, etc. Geological prediction is important to prevent disasters. Taking the Daxiangling tunnel as the example, the paper predicts the complex geology in the tunnel by the TGP206 and analyzes the geology at the macro and micro levels. The results show that this way can improve the prediction effect for unfavorable geology and the precision can reach to 95by comparing to the real condition. Then, the way provides a new idea for the safety of the tunnel construction, and technical information and the experience to the similar projects.

Abstract:XiaoJiang River is the largest tributary on the north of the middle part in Three Gorges reservoir area, because of predominant hilly cropland with purple soil, the dissolved nitrogen from surface and subsurface runoff caused by raining accounts for most part of the nitrogen pollution in water. This paper develops the annual pollution models based on the characteristics of topography and soil, etc., of the basin in order to study dissolved nitrogen pollution, and introduces a Semidistributed Land Usebased Runoff Processes (SLURP) hydrological model into the surface and subsurface runoff simulation which is an important part of nonpoint source pollution modeling. Integrated with the geography information system technology, the annual temporalspatial distribution of the dissolved nitrogen in the basin is simulated and the load at the watershed outlet is estimated from 2000 to 2007. The results show that the load from cropland is up to 68.3~76.8of the total load, in which over 85 from croplands and then rural settlement is 23.2~31.7.

Abstract:Four design schemes of flow deflector in the gas flue of selective catalytic reduction (SCR) denitrification system are simulated based on Kε turbulence model and 2D model by Fluent. By analyzing the speed profile and pressure drop of the import and export, the effects of the flow deflector on the import and export speed profile, pressure drop, and energy dissipation are studied. It can be concluded that flow field distribution could be significantly improved by putting the flow deflector into the gas flue. Reasonable flow deflector design can not only make the flow field distribution uniform but also reduce the pressure drop and the energy dissipation. With the increase of flow deflector dimensions, the flow field distribution will be more uniform. The pressure drop and the energy dissipation will increase because of the increase of resistance caused by flow deflector. The research results are helpful for designing selective catalytic reduction denitrification system. 

Abstract:A complexometric extraction method of extracting 6nitro1 and 2azoxynaphthalene4sulfonic acid in its mother solution is studied. At the room temperature, taking 30(v) trioctylamine(N235) chloroform solution as an extractant, when the extractant and mother solution volume ratio is 1:1 and extracting 60 minutes, the extraction yield can reach 96.1. Using 12(m) NaOH solution as a strip agent, when the organic phase and strip agent volume ratio is 2:1 and stripping 60 minutes, the strip yield can reach 94.3.

Abstract:This study investigates the mercury distribution characteristics at different particle sizes, leaching characteristics with different impact factor such as the different time, the different ratio of liquid to solid and the different acidity, leaching toxicity and speciation of mercury in Municipal Solid Waste Incineration (MWSI) fly ash in Three Gorges area. The results show that the average content of mercury in the fly ash is 8.52 mg·kg1. The content of mercury in the fly ash is higher at the particle size of 100 μm, and which increases with the decreas of the ash particle size. Mercury leaching content closely relates to environmental conditions. The leaching content of mercury increases with the increase of pH and L/S, while it decreases with the leaching time. The content of mercury at oxidable form and the residue form are high, and whith at exchangeable form and reducible form is relatively low.

Abstract:There are some disadvantages in the traditional ECG exercise, such as noises in the acquired ECG, restrictions on the kind of patient who can use this method and the low sensitivity and specificity for the ST depression diagnostic metrics. New equipment for diagnosing Chronic Myocardial Ischemia based on ST/HR slope and power test bicycle is designed. The ST/HR slope is calculated with computer software, avoiding heavy burden and errors for human computation. The power test bicycle decreased noises and improved other disadvantages for treadmill. It is demonstrated with experiments that this system yields better performance with higher sensitivity (93.8) and specificity (94.5) than the traditional system does.

Abstract:Although allowing organizations to build loosely coupled, distributed heterogeneous enterprise application, ServiceOriented Architecture (SOA) doesn’t support direct data access or manipulation to heterogeneous data sources. To lower the dependency of data access on applications, a preliminary research is conducted on data access mechanism adopting data service in SOA. Based on the analysis of applying traditional data access methods to heterogeneous data sources in SOA, data service is researched and a data access method using data service is proposed, aiming at providing direct access to data sources using web services. ADO.NET Data Service from Microsoft is employed to implement data service and examples are illustrated, proving that data service not only provides direct access to data sources, but also can be integrated into SOA through standard web service interfaces. As is shown by the comparison with other data access methods, data service offers uniformed access to heterogeneous data sources without involvement of individual applications.

Abstract:Aiming at solving the problems existing in the traditional data transmission system of Industrial Computerized Tomography (ICT), which usually uses PCI and ISA bus, resulting in high price, poor scalability, low transmission rate, complex fixing and complex routing, and cannot fulfill the demand for research and production, a set of ICTbased USB 2.0 highspeed data transmission system model is proposed. The system takes a FPGA chip as core logic control module, which controls communications with the USB chipset. The whole hardware designation is described in terms of the performance of reliable data transmission, highspeed and stability. Experimental results show that the proposed method improves the system’〖KG*8〗s stability and reliability. It can satisfy the requirements of ICT transmission .

Abstract:By means of discovering crosscutting concerns from legacy systems, aspect mining intends to help migrate the systems to an aspectoriented design. An improved method based on maximum tree method for aspect mining is presented. The method uses aspect ideas to capture the runtime methodcall information by mining crosscutting concerns from dynamic behaviors, and then constructs a methodcall relationship data matrix. Based on fuzzy similarity relation theory, by introducing the similarity, an object similarity matrix is constructed, and the maximum tree method is used to identify the crosscutting concerns in the system. The method can provide a basis for system’s software reconstruction and reusability. An experiment is conducted to verify the validity of the method. Compared with the existing typical mining methods, the method shows the virtue of clear implementation and high efficiency.

Abstract:Based on the good chaotic properties of tangentdelay ellipse reflecting cavitymapping system (TDERCS), a kind of novel substitution boxes were constructed. The cryptographic properties, such as bijection, nonlinearity, strict avalanche, independence of output bits, the differential approximation probability and the nonlinear approximation probability of the Sbox are analyzed. The investigation method for the strength of the Sbox with the discrete chaotic system proposed by Kocarev is discussed. Theoretical analysis and backtesting results show that the method is efficient and easy to put into practice, while the constructed Sboxes show better cryptographic properties than the Sboxes based on other chaotic system, which can be used to improve the existing encryption scheme.

Abstract:Aiming at the problem of link fault restoration in ASON, an improved equalizing routing algorithm (ERA) is introduced to proportion the load at the routing phase. In order to solve the easy blocking problem for the network without wavelength converter because of the wavelengthcontinuity constraint, the algorithm WRCA is proposed at the wavelength assignment phase. This algorithm is realized by adding collision detection object (CDO) in the path message of the resource reservation protocol with traffic engineering extension (RSVPTE). Depending on the value of the CD flag, different wavelength selection strategies are applied at the destination node, and the blocks resulting from wavelength reservation collision are reduced. The simulation experiments compare four wavelength assignment algorithms with the same routing algorithm ERA. The results show that compared with the traditional first fit algorithm (FF) and random fit algorithm (RD), the FF and RD employing CD scheme can effectively reduce the blocking ratio of the whole network, and enhance the practical applicability of the restoration algorithms.

Abstract:A multipath interference cancellation RAKE receiver with nested structure is proposed based on successive interference cancellation method. In the proposed method, the present branch and the demodulated branch form a substructure of the RAKE receiver, while the RAKE substructures are nested. The data estimate of the present branch is obtained by the maximum ratio combination of the demodulator output in the corresponding RAKE substructure. The update of the regeneration signal is achieved by replacing the previous branch data with the present branch data estimate . Performance of the new RAKE receiver was analyzed. Theoretical analysis and simulation results show that the new RAKE receiver with simple structure and easy implementations can suppress the multipath interference and improves the BER performance.