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Valve orifice is the common place that the cavitation easily occurs in the hydraulic systems. This paper introduces a criteria to estimate the inception of the cavitation of the V-type valve orifice with the stress state. Based on this criteria, a cavitation model which considers the dynamics of the cavity and incompressible gas is proposed to analyze the pressure, stress and the cavitation distribution of the phase in the V-type orifice. The distributions of the cavitation along the axis and the cross section are analyzed. The simulation results show that the cavitation is easily occurred in the downstream just after the orifice and the bubbles are mostly gathered in the top of the cross section which is vertical to the axis of the flow field. The simulation results is reasonable according to the facts. Accordingly, the cavitation of the V-type orifice is predicted reasonably. The research and results of this paper are useful for the design of the hydraulic valves.

In some areas such as micro-mechanical, ultra-precision machining, nanotechnology, the high-precision positioning and very fine vertical scanning motion are needed urgently. Therefore, the Z-axis micro-displacement driving control technology has become the key technology in these areas. The piezoelectric ceramics actuator and stepper motor were integrated into hybrid linear actuator in Z-axis nanopositioning stage, and this can simplify the structure of the drive system. By calculating the gravity center of the vertical scanning system, and using single counterweight, a new one-arm bridge type structure was built. Appropriate tension and current sensors were also equipped in order to real-time monitor the drive status. It is feasible to balance the weight with this simplified system structure, and also guarantee the driving control accuracy of nanopositioning stage. Besides, in the structural design, the Abbe error can be reduced greatly by placing the stage center, grating ruler and displacement measurement centerline on the same line with grating reading head. The driving travel of nanopositioning stage is 150mm, and driving resolution is 1nm. The designing method introduced gives a scientific method and practical reference for the development of z-axis driving control system.

The design height of a concrete sand-gravel dam is up to 251 meters, which has strong unloading rock masses with great depth on the left bank. According to the topographic and hydro geologic conditions of the dam site, a three-dimensional finite element model for seepage calculation of the dam is established. Based on the equivalent continuum method, the effect of anti-seepage and drainage system within run-time with normal storage level is studied, meanwhile, the seepage elements are obtained, including the seepage of the groundwater, the discharge of the dam, the seepage gradient of the dam body and the impervious curtain and so on, thus the conclusion that the anti-seepage and drainage system is reasonable is verified. What’s more, the influence of the different length and depth of the anti-seepage curtain to the distribution of groundwater seepage as well as the effect of "L" type drainage in the dam body are analyzed in order that the suggestion of the optimization of anti-seepage and drainage system is put forward for the high concrete sand-gravel dam.

The main dam of the upper reservoir of Zhen'an pumped storage power station in Shaanxi Province, China, is a concrete face rockfill dam with height of 125.90m and crest length of 363.00m. The in-situ drilling and geological prospecting show that the groundwater level is higher than the normal water level in part of the left bank and the reservoir tail, leading to the reversed seepage problem of the groundwater through concrete slab under drawdown condition. Based on the establishment and calculation of the three-dimentional finite element seepage model, the analysis and comparison was made between the overall seepage prevention composed of concrete slab + composite geomembrane and the partial seepage prevention composed of concrete slab + composite geomembrane + vertical grouting curtain [1,2]. The result was found that the seepage gradient requirement was met up by both forms, but due to the prevention of supply from the groundwater in the left bank and reservoir tail, the uplift pressure was formed locally in the overall seepage prevention, whereas such problem did not exist in the partial form. With the extra water supply from the groundwater, the partial seepage prevention works better in terms of leakage. Besides, the design of coarse sand drainage layer is well-served in reducing the water pressure beneath the composite geomembrane on the bottom of the reservoir [3]. It is suggested that the high groundwater should be fully utilized for security and economic benefit. The achievement and experience of this partial seepage prevention design should be taken into consideration for other similar projects.

The Rumei core wall rockfill dam hydropower station is in Lancang River in the Mangkang county of the Tibet autonomous region with maximum height of 315m and crest length of 666.2m. Due to the high core wall rockfill dam has been more than 300m high, water level sudden drawdown of the unsteady seepage condition shall be taken into consideration, according to the given water level drop speed (5m/d) calculate condition, analysis of the seepage field distribution of the different water level, free surface of different time, each material partition of the dam and foundation soil seepage gradient, etc are given. The results showed that the free surface of the upstream dam shell rockfill body dropping fast than the water level dropping speed of the reservoir. The seepage gradient of the upstream shell is very small, which will not cause adverse effect on the upstream dam slope stability. The free surface of the downstream dam shell rockfill body changes little, which will not cause adverse effect on the downstream of the dam slope stability. As the water level falls, the free surface of the core wall dropping speed is slow, far less than the water dropping speed of the reservoir. In the process of emptying reservoir, the free surface of the core wall remains in a high position, which should cause enough attention.

Base on the design of seepage control, the three-dimensional non-steady saturated - unsaturated seepage finite element analysis program CNPM3D is used to establish the three-dimentional finite element seepage model of junction area during operating period. The seepage field of dam site area is studied under the different anti-seepage curtain arrangement scheme. Specifically, the seepage gradient and the seepage discharge of the panel, major material zone, foundation curtains and two sides abutment curtains are analyzed to evaluate the stability of the major district of dam area, in order to provide suggestions for choosing the seepage control standard in the next deepen design stage.The calculation results show that the panel and the impervious curtain anti-seepage effect is remarkable.Impervious curtain can greatly reduce the total seepage flow of the dam and its foundation.However the curtain deepened to 1Lu has little effect on seepage discharge. It is showed that the seepage prevention standards of 3 lu should be proposed in the deepen design stage for both security and economic benefit. The achievement and experience of this seepage prevention design should be taken into consideration for other similar projects.

The main dam of Banqiao reservoir consists of the concrete overflow dam and the earth dam in both sides, which are connected by concrete lateral key wall. Field observation shows that serious leakage problems exist at the connection of the overflow dam and the earth dam in right bank. According to the real size of structures, the FEM model are established to calculate and analysis the seepage field characteristics at the connection part. The potential ground water level shows that the reservoir water flowing to the downstream bypassing and passing through the lateral key wall and the anti-seepage curtain. And there exists partial seepage passage at the connection part. As the contact seepage gradient along the lateral key wall is uneven, the contact leakage at the connection part is not fully safe although the average contact seepage gradient is within the permissible range. Effective measures should be taken to solve the seepage defects at the connection part.

Seepage control is one of the important problems when designing a hydropower station. The upper reservoir of one hydropower station was built by excavation and backfill partly. Its impermeable program is the combination by concrete panel, geomembrane and vertical curtain. With the finite element method , the model of the dam has been built. The potential distribution of groundwater in the library on the seepage filed is analyzed. It also analyzes the seepage slope of dam body, dam foundation and reservoir and calculates the seepage discharge and replenishment at the situation of normal storage level. The results show that potential distribution law of reservoir seepage field is clear and definite. The effect of cutting water head by anti-seepage curtain and curtain downstream under protective layer at the bottom of the coarse sand and back packing drainage is remarkable. The panel and geomembrane have an effect on cutting waterhead. The seepage flow of upper reservoir is 488.16m3/d and the supply flow is 1019.52m3/d. So the control scheme of the upstream seepage is reasonable technically.

As an important part of the structure of hydroelectric power station, surge shaft is embedded in the rock mass, whose body size and loading conditions are typically complex. Thus, it is necessary to evaluate safety of the design scheme in order to ensure construction safety. With upper background, three dimensional finite difference model of the surge shaft and surrounding rock of a hydroelectric project in Zambia were established based on three dimensional nonlinear finite difference analysis method. Calculation of the surge shaft stepped excavation with supporting at all levels of the construction process was done. The deformation and stress state of the surrounding rock of surge shaft and its variation law in excavation process was analyzed. Furthermore, the stability of surrounding rocks and rationality of the designed support measures were evaluated.

The Haokou power station is located in the south of Wu Long in chongqing, which is a medium-sized hydropower project given priority to electricity. The Dam located in south bank of Wujiang river downstream of Furong river has the catchment area of 7400 km2, total capacity of 94.12 million m3, installed capacity of 125 MW power . After the excavation of the main building, trailing edge to form 30 m high rock slope is tangential. Slope rock mass is given priority to with weakly weathered shale, mudstone, shallow accumulation horizon, thickness is about 0.5 m to 6.0 m. In analysis of slope stability, the FLAC 3d and the strength subtraction method was used. Considering of gravity, the shore web of pressure, water pressure and reinforcement bolt load combination, the stress response, displacement response, plastic zone as well as the safety factor of slope was analyzed. The calculation results show that the slope is stable.

The stability of high rock slopes under the flood discharge atomization and rainfall is an in-negligible problem especially for the hydropower station with high head during the flood discharge. According to the complicated geological conditions of a high rock slope with the flood discharge problem in China, the method of the saturated-unsaturated unsteady seepage if used, thus the finite element model for the high rock slope in the downstream of the power station is set up. Based on the model, the distribution regularities of the unsteady seepage field of the rock slope is studied under the different discharge atomization and rainfall intensity. Moreover, based on the theory of continuous-discontinuous deformation, the finite element model is set up to analyze the stability of the slope, thus the deformation law of slopes under the flood discharge atomization and rainfall is studied and the safety of the slope is evaluated, and what's more, the engineering measures for improve the stability of the stability of the slope is put forward.

Two weak acid resins (WT-1, WT-2) with different pore structures were prepared through suspension polymerization from methyl acrylate (MA) and divinylbenzene (DVB). Cu2+ was employed as the adsorbate and bath experiments were carried out to investigate the adsorption performance of the two resins. The addition of porogen (toluene) enlarged the exchange capacity, specific surface area and average pore diameter of resins, leading to the faster adsorption rate and higher maximum adsorption capacity. The adsorption capacity increased 3.5~28.5% with the rise of porogen/monomer ratio from 0 to 30%. This work shows the porogen influence on the adsorption kinetics and thermodynamics of weak acid resins.

Two methods based on modal decomposition in circular cylinders are presented here. One is based on bi-orthogonality relation and the other is based on boundary discretization for mode matching. The two methods are comprised in numerical implementation and the efficiencies are evaluated.

For the leakage problem caused by geomembrane defect, the unstable saturated-unsaturated seepage theory and Galerkin finite element method have been adopted. So a three-dimensional finite element numerical model of an earth-rock dam with geomembrane anti-seepage system is simulated by the unstable saturated-unsaturated seepage finite element method. The influnence on seepage field for the varying degrees of geomembrane damage is analyzed, and the overall and local seepage field characteristics of the dam for geomembrane defect leakage are discussed. The results show that the numerical method provides an effective way to study the leakage problem of geomembrane defect.

Seepage failure is an important factor in causing dam-break of earth-rock dam, so the study of anti-seepage reinforcement for dilapidated reservoirs is always an important topic to earth-rock dam. Changli reservoir, since the completion, soil flow and failure by piping occur in dam slopes, the safety of downstream residents has been threatened both in life and property. Based on the comparisons of the effects of anti-seepage reinforcement schemes,the result shows that, for this clay dam, concrete cut-off wall can improve the seepage state obviously and has a higher operational stability. Thus, the concrete cut-off wall is designated as the recommended anti-seepage scheme for Changli reservoir.

Based on M language offered by Comsol Multiphysics analysis platform, a 3-D finite element model of a high arch dam was established. In this paper, a practical engineering was taken to be as a case.The coupled seepage-stress field was compared with uncoupled condition under normal storage level. The seepage, stress and displacement fields of the dam were analyzed for discussing the coupled effect. The results show the similar distribution of seepage, stress and displacement fields in the two conditions. However, compared to the uncoupled one, the potential distribution of seepage field is close to downstream, each displacement component increases at different rates, the tensile stress of the upstream rock and the compressive stress of the downstream rock both increases in the coupled condition, which enhances the uplift pressure in the foundation. So the coupled effect of seepage and stress is not beneficial for the dam safety, which cannot be ignored under high water pressure.

First analyzing electromagnetic compatibility system of the wired circuit, and then electromagnetic shielding, PCB board electromagnetic compatibility and filtering are used to develop an anti-broadband electromagnetic interference wired phone. It can resolve practical problems of SLT dialing error in strong electromagnetic interference, voice unclear and intermittent communication. After 30 days test, experiment shows that in 50m radiating field of high-power VHF radar or shortwave radio, speech intelligibility of phone designed was higher than that of general phone and had no whistling or ringing.

In order to meet the high speed, high precision, high reliability of the packaging machine, a novel control system is provided. In the hardware, the main circuits consisted of main processor module, memory module, temperature measurement and control module, input signal detection module, material split packing module, output driver module, human-machine interface module, system monitor module, power module and JTAG debug module, etc. In the software, the multi-tasking operating system μC/OS-Ⅱ and the graphical user interface μC/GUI were successfully transplanted into LPC2478. Then an experimental platform was established. And many control tasks, including automatic measurement, making bags, loading, transferring, pumping vacuum, sealing and data display, were automatically and continuously executed on the platform. Finally the results show: the machine can package 30 packets (5 g per packet) in a minute; the packaging errors ≤ 0.2 g; the packaging qualified rates ≥ 93%. In conclusion, the system performance is good.

Using an atmosphere simulation test platform，the performance of a common rail diesel engine when the engine was fueled with diesel fuel (B0) and different blending ratio of biodiesel (B10, B20, B30)．The results show that at the same altitude(81kPa), with the mixing ratio of biodiesel increases，the common rail diesel engine has higher brake specific fuel consumption and lower power，but it has lower smoke．The biodiesel has a litter influence on the brake specific fuel consumption and power of the common rail diesel engine. The power of B30 is reduced by 4.38% in comparison with B0 maximally. The brake specific fuel consumption of B30 is increased by 4.32% in comparison with B0 maximally. The smoke of B30 are reduced by 22.5％, 38.6%, 57.1% in comparison with B0 maximally.

To study the effect of the biodiesel on the performance of the high pressure common rail diesel engine performance, a experiment is conducted about the high pressure common rail diesel engine uses diesel fuel and different blending ratio of biodiesels. The results show that with the rising of the altitude, the engine power and the brake specific fuel consumption reduce, exhaust gas temperature increases; At the same altitude, the engine fueled with different blending ratio of bio-diesel has higher brake specific fuel consumption in comparison with fueled engine, but it has lower power, with the increase in bio-diesel blending ratio, engine power, fuel consumption increase.

The irradiation-induced hardness change in a commercial P92 ferritic/martensitic steel has been investigated through 3.5MeV Fe-ions irradiations to a dose of 0.29dpa at room temperature, 673K and 973K combined with nanoindentation techniques. The results show that irradiation-induced hardening was observed at the room temperature, and softening occurred at 673K and 973K. The hardening at room temperature is ascribed to the crystal defects in the steel generated by Fe-ions irradiations. The softening at 673K and 973K may be caused by the recovery of the defects.

Serrated flow behavior of the 316LN austenitic stainless steel was investigated through tensile tests at initial strain rates of 2×10-5 to 10-4 s-1 at temperatures ranging from room temperature to 1048 K. Serrated flow occurred at room temperature and 6981048K at the strain rate of 2×10-4 s-1, as well as at temperatures of 623673 K at the strain rate of 2×10-5 s-1. Type A, A+B, C and E serrations appeared. The activation energy for the occurrence of serrated flow at high temperatures was about 327 kJ/mol. The dynamic strain aging caused by the interaction between substitutional solute Cr atoms and moving dislocations is considered as the mechanism of serrated flow at the temperatures higher than 973 K.

In order to digitize the signal of high frequency or ultra-high frequency, clock distribution technology with the same frequency but different phase is utilized as a solution to this difficulty. The principles of high-speed analog-to-digit converter (ADC) by the lower rate ADC module, key technology and key module of the data acquisition systems are studied. From the aspects of system architecture, clock distribution module based on the AD9520, ADC module based on the AD9480 and data processing, the design method of ultra-high-speed ADC by clock distribution mode are explored. The results show that: driving many ADC modules with serial clocks of the same frequency but different phase in parallel to sample the same signal, the sampling frequency of the ADC system is the sum of each ADC sampling frequency. Four AD9480 modules are driven by four-way 250MHz clocks with phase fault 90°, respectively. And 1GHz samples per second can be attained, which is four times of the sampling frequency by monolithic AD9480.

For the echo of the laser signal was relatively weak and accompanied by a lot of noise in a foggy condition, a multi-pulse cumulative method for enhancing weak laser signal was proposed. The enhancement principle and method of multi-pulse signal accumulation was studied, and with it the weak signal was processed. The matched filter algorithm was used to extract the characteristics of laser echo signal, the original signal and the accumulated signal was processed by the matched filter, respectively, which greatly improves the signal to noise ratio (SNR). The experimental results show that: four separate laser signals accumulated together enhance SNR by twice; the accumulation of multi-pulse laser signal can effectively improve SNR, and the matched filter can strengthen the signal while suppressing noise.

with the difficulties of extracting the feature of faint laser signal reflecting from non-cooperative target in foggy conditions, the spatial correlation threshold filtering approach was proposed based on spatial correlation filtering. The thought, theory and implementation methods of the spatial correlation threshold filtering was elaborately studied, especially, the selection of the threshold for the filter was analyzed. A comparative study of threshold filtering, spatial correlation filtering and spatial correlation threshold filtering was carried out to verify the filtering effect for the laser signal reflecting in the foggy environment, the experiment results shows that: spatial correlation threshold filtering method has the most effective filtering. The processing results show that the new method can effectively eliminate noise and keep weak laser signal characteristics, which lays solid foundation for identification of target nature.

Based on the actual conditions of the project and related experience, the seepage model of diversion tunnel and its surrounding rock mass was built to analyze its seepage stability. The seepage field was calculated by using finite element method (FEM) and cut-off negative pressure method. Two typical cross-sections and working conditions were chosen to evaluate the seepage stability of the surrounding rock mass. According to the results, the seepage gradient is larger when one tunnel is filled with water while the other is empty. The maximum seepage gradient is less than the allowable seepage gradient, so the surrounding rock mass of the diversion tunnel can meet the demand of seepage stability.

The irradiation hardening behavior in a commercial ferritic/martensitic steel P92 has been investigated through 250KeV Ar-ions irradiations to a dose of 10dpa at 473, 673 and 973K combined with nanoindentation techniques. The results show that irradiation-induced hardening was observed at the all irradiation temperatures. There appear to have no previous reports of the irradiation-induced hardening at the temperature higher than 873K in ferritic/martensitic steels. Irradiation-induced hardening at elevated temperature of 973K has been found, for the first time, in ferritic/martensitic steel. The irradiation-induced hardening at 973K in the ferritic/martensitic steel P92 may be ascribed to the defects in the steel generated by Ar-ions irradiation.

Serration behavior of 2090 Al-Li alloy was studied by tensile test combined with modifying the structure of δ-precipitates through reversion heat treatment. The serration type was strongly affected by the structure of δ-precipitates in the alloy matrix. With decreasing the amount and increasing the spacing of δ-precipitates, type A and type B serrations disappear, whilst type C serrations become dominant gradually. The serration behavior in the 2090Al-Li alloy can be attributed to the shearing of δ-precipitates by mobile dislocations during tensile plastic deformation.

Bank slope seepage field is analyzed by saturated-unsaturated seepage theory under the three times cycle conditions of water level rising and drawdown . The pore water pressure distribution laws of the water level rising period, the stabilization period, the period of decline and decline stable period for every cycle are researched. The result shows soil near slope region is saturated easily after many rounds of water level rising and drawdown, and saturation region gradually increases. Soil phreatic line near slope falls fastly in the drawdown period, away from the slope, phreatic line declines slowly.

Sizing of material flaw is addressed in the multipath scene, and a method is developed to detect an isolated sized flaw and estimate its height based on imaging theory of different path profiles. A signal model based on the multipath higher order reflections of the flaw is built to detect the sized flaw. Multipaths are predicted and identified on the basis of the direct reflection path, which is relatively easy to be identified using the conventional flaw detection techniques. Direct reflection path and combined path are applied to detect the flaw from the top, and multipath w is to detect its bottom of the flaw. Ultrasonic imaging is formed and synthesized by all the identified multipaths, which shows the size of the material flaw. Simulations and experimentations demonstrate that the flaw sizing can be calculated utilizing the time-of-arrivals of the multipath signals.

According to the actual engineering conditions of Haokou RCC Gravity Dam, the 3-D FEM model of the typical overflow dam section and its foundation is set up. Using the response spectrum method, the responses of earthquake acceleration, displacement and stress of the dam and their distribution laws were studied under the seismic loading, and the anti-sliding stability of dam is also analyzed. The calculation results show that under the design earthquake condition, the maximum principle stress response of dam body is 2.26MPa, which appears at the dam heel. The safety factor of stability against sliding on the face of the dam foundation is 1.43 and the stability against deep sliding is 3.2. So this dam section can meet the strength and stability requirements of standard, its earthquake-resistant safety could meet the requirements of standard.

This study utilized the reaction of O2/N2gases and Al0.67Ti0.33/Cr (99.9%) dual targets to synthesize (Ti,Al)ON/CrON multilayered coatings on AISI M2 steel by cathodic arc deposition system. Thermal stability and corrosion resistance of the multilayered coatings for aluminum die casting applications, along with coating structure were investigated. The results showed that the structure of multilayered coatings was a B1 NaCl type. The formation of oxide phases by introducing oxygen to react with Al, Cr, and Ti elements was confirmed by XPS. The thermal stability of oxygen-doped AlTiN/CrN coatings was higher than that of one without oxygen. After the immersion tests in Al-alloy melt, the oxygen-doped AlTiN/CrN coatings deposited at the O2/N2ratio value of 0.3 had the best improvement on the corrosion resistance among all the coated specimens.

According to the information about underground damage in earthquake all over the world, it is summarized that earthquake damage is caused by mountain slope failure, the collapse of cavern’s export, dislocation damage of cavern’s cross-section, great displacement along the fault intersection, spalling of surrounding rock, disturbance or deformation of the support and lining system, et. The earthquake damage factors of underground cavern were analyzed by using numerical simulation techniques. It is shown that when the earthquake intensity value is high, or the initial stress field is small, or lining stiffness is high, the underground will more easily be destroyed by earthquake. Compared with the square tunnel and horseshoe-shaped tunnel, dynamic stability of circular tunnel is better. The export of cavern is vulnerable to earthquake damage.

Evaluation indexes (monitoring value) set in safety evaluation of dike, it was difficult in conforming the range of evaluation indexes, and could not reflect characteristic of outburst destroy. Catastrophe theory is a kind of mathematical method that problems of transition, discontinuity, and abrupt qualitative change based on analysissitus, problems about how a system of continuous quantitative change to evolving into jumping qualitative change can be analyzed. Firstly, the relation between deformation of dike with components of water pressure, temperature and time effect is analyzed, subdivision lemma of cusp catastrophe theory is cheesed, expression of potential formula on horizontal deformation is carried out based on influence of factor of time, water pressure and temperature. Moreover, normal form of catastrophe is advanced and critical rules of dike safety are put forward, evaluation model based on catastrophe theory is established. Finally, the model is validated with dike of Yellow River. Analysis shows that evaluating conclusion of the model is as the same as the practice, and it can not only reflect outburst destroy character of dike, but also evaluate safety degree in quantity, thus the model is good in adaptability and precision.

Numerical manifold method (NMM) is based on the blocky theory which absorbed the advantages of finite element method based on the continuum mechanics, discontinuous deformation analysis method based on the non-continuum mechanics and analytic method. According to the finite covering technology of modern manifold analysis method, uniform solving format on continuous-non-continuous problems is established by taking the continuous and discontinuous cover function which can be used for the numerical simulation of large deformation and continuous-discontinuous deformation. The calculation program is worked out based on the method above and it is applied to the actual project.

Accurate in apparatus, complex in operation, expensive in fund and plentiful in time, test of unsaturated soil is difficult. Influence of status of dry and wet and degree of compacting was not considered generally when Duncan-Chang model was be used to unsaturated soil. With parameters of model served as constants, it was not consistent with the practice that parameters would be changed with saturation and water content and its application would be limited. General triaxial tests of drainage and consolidation about dry density and water content combined are carried out, influence of relation between stress and strain about clay is discussed, mathematical equations of parameters of Duncan-Chang model are established, thus modified Duncan-Chang E-B model of unsaturated clay is carried out that influence of dry density and saturation can be considered. From study we can see, on the one hand, characteristics of stress and strain about unsaturated clay are influenced obviously by saturation and dry density, the main parameters of E-B model keep close correction with dry density and saturation, and the both mutual effect can be expressed by multiplication. On the other hand, status of compacting and process of gradual change from dry to wet can be described with modified E-B model. Thus it will be more complete in factors considered, inosculate in practice, and convenient for use.

Ultrasonic signature of flaw is studied in the multipath scene, and a method is developed to localize the flaw by only single mono/bi-static measurement. A signal model based on the concept of multipath is built to construct flaw position, of which multipath scenarios are reviewed for signature of flaw depth. Multipath scenarios may be identified by direct path, which is relatively easy to be detected. Algebraic solution is proposed to solve the multipath equations to obtain the position of the flaw depth. Experiments show that the solution of the flaw depth is valid.

This paper presents the design methods of CQU-DTU-B21 airfoil for wind turbine. Compared with the traditional method of inverse design, the new method is described directly by a compound objective function to balance several conflicting requirements for design wind turbine airfoils, which based on design theory of airfoil profiles, blade element momentum (BEM) theory and airfoil Self-Noise prediction model. And then an optimization model with the target of maximum power performance on a 2D airfoil and low noise emission of design ranges for angle of attack has been developed for designing CQU-DTU-B21 airfoil. To validate the optimization results, the comparison of the aerodynamics performance by XFOIL and wind tunnels test respectively at Re=3×106 is made between the CQU-DTU-B21 and DU93-W-210 which is widely used in wind turbines.

As one of the key structures of hydropower underground projects, buried high-pressure steel bifurcations have complex structures and undefined force states. Based on practical condition of the buried high-pressure steel bifurcation of Sandaowan Hydropower Station, a nonlinear three-dimensional finite element model with parametric design language is established to analyze the changing law of the stress of the lining affected by the dimension of the strengthened beams. It is proposed that to increase the height of the strengthened beams can be reduce the phenomenon of stress concentration effectively in the bifurcation, which can be served as a theory reference for the engineering design and construction.

The enhancive effects of lactic acid on the antibacterial activities of haw pectic oligosaccharides (HPOS) against the Gram positive bacteria Staphylococcus aureus, Bacillus subtilis and Streptococcus faecalis, were investigated. Both HPOS and lactic acid showed dose and pH dependent antibacterial activity against S. aureus and B. subtilis. S. faecalis was sensitive to the HPOS but was resistant to the lactic acid. The antibacterial activity of HPOS against these three bacteria could be enhanced by co-treatment with lactic acid. The results revealed that HPOS may be useful as a food preservative, and lactic acid was able to enhance the antibacterial activity of HPOS, allowing for a further improvement in its efficiency. This additive effect obtained with lactic acid would likely result in a reduction in the dosage necessary for food preservation.

Purple sweet potato pigment is a natural food pigment, the stability is important to its quality assurance. The effects of metal ions on the stability of purple sweet potato pigment were investigated. The results showed that Mg2+and Fe3+ were conductive to pigments stability in the initial storage, and with the concentration increased, the pigment was more stable. But K+, Ca2+, Na+, Cu2+, Mg2+ and Fe3+ had brought the color density, the color intensity and the preservation rate of purple sweet potato pigment down in the long-term storage.

According to the practical situation, the 3-D finite element model of Sandaowan underground powerhouse caverns on Taolai River is set up for analyzing the behaviors under earthquake action. Based on static stress field of the surrounding rock mass, and with the selection of appropriate seismic waves for dynamic time-history analysis method, the dynamic responses of underground powerhouse caverns are analyzed. It is shown that the time-history waveform of dynamic displacement of given points has a very similar variation regularity with that of acceleration, and the wave phases of both are almost synchronous. The dynamic displacements and principal stresses of the given points on rock walls are with the vibration of low-frequency characteristics, the acceleration response is with the vibration of high-frequency characteristics.

Subsurface drip irrigation (SDI) that has a wide application prospect is one of the high efficiency water-saving irrigation techniques. Research on regulation of soil-water dynamics in irrigation design parameters of SDI has important points in improving its irrigation design and guiding its practical function. In this study, soil wetting patterns were investigated in laboratory experiments which were operated at three different dripper discharges (0.76, 1.15 and 1.25 l h-1) and two different irrigation amounts (4.6 and 9.2 l). The results showed that, (1) with the increase of dripper discharges from 0.76 l h-1 to 1.25 l h-1, water content around the emitter are increasing from 0.225 cm3 cm-3 to 0.300 cm3 cm-3, (2) increasing the dripper discharge and irrigation amount increased the size of the wetted zone, (3) upward distance of the wetting front is less than downward distance and horizontal distance of the wetting front presents symmetry distribution at the same the dripper discharges and irrigation amount, (4) with the increase of irrigation amounts from 4.6 l to 9.2 l, water contents of the vertical and horizontal direction are increasing 10% to 20%.

In the light of Information Island phenomenon existing in the current police system and inadequate excavation of data, this paper advances the necessity of establishing police intelligence data warehouse system. Vs.net 2008 and SQL Server 2008 are used to design and implement the police intelligence data warehouse system, and more over probes deeply into the technology of ETL.

Rare earth (RE) ternary complexes of Eu0.5Ln0.5(NPPD)3×DPQ (HNPPD = 1-(naphthalen-2-yl)-3-phenylpropane-1, 3-dione; DPQ = Dipyridobenzoquinone; Ln3+= Nd3+, Er3+, Ce3+, Dy3+), Eu1-xYx(NPPD)3×DPQ and Eu1-xLux(NPPD)3×DPQ (x= 0.0, 0.1, 0.3, 0.5, 0.7, 0.9) were synthesized by the reaction of RECl3×6H2O with HNPPD and DPQ in stoichiometry. The UV-vis and fluorescence properties of the complexes were investigated. The experimental results show that the luminescence efficiency of Eu3+complexes was enhanced by doping some other lanthanide ions.

Difficult in soil-water characteristic curve achieved, existence of non-uniqueness and indistinct in influence of unlinear deformation characteristics of soil about density and water content, deformation characteristics of unsaturated soil were studied difficultly with general triaxial test, thus direct application of unlinear Duncan-Chang model in unsaturated soil was restricted. General triaxial tests with combined dry density and water content are carried out, changing rules of parameters of Duncan-Chang model are summarized, mathematical functions between dry density, saturation and parameters of the model are established. Analysis shows that deformation characteristics of unsaturated clay are influenced obviously by saturation and dry density. Among them, the larger the saturation, the higher strain becomes under the condition of the same dry density and main stress difference, and the less the dry density, the higher strain becomes under the condition of the same saturation and main stress difference. Moreover, the main parameters of Duncan-Chang model keep close correction with dry density and saturation, and the both mutual effect can be expressed by multiplication. This shows that mechanical characteristics of unsaturated soil can be studied with general triaxial test, thus it will be used easily in project.

An analytical solution based on modal decomposition is presented to investigate Lamb wave scattering at plate end. Take boundary condition into biorthogonality relation, a matrix equation is established with all matrix elements have analytical expressions. The scattering feature is then expressed in matrix form, named as reflection matrix, which has explicit expression composed of those matrixes. Calculation examples have be implemented when antisymmetric modes are reflected. Scattering coefficients are figured out in a range when frequency-thickness product vary from 0 to 8kHzm, to prove the calculation efficiency. The calculation precision is very close to the least square method based on model discretization.

Good performance of driving power supply is the key to achieve high-precision positioning of the piezoelectric ceramic. In this paper, mainly from the expansion of power channel, lower ripple and interference, reducing the volume and temperature control of amplifier such aspects, developed PZT multi-channel power supply based on PA93 power amplifier, and completed the corresponding experiments of the calibration characteristics. By testing, the output voltage of eight channels shows good linearity, the nonlinear error is less than 0.05％. the resolution is 6mv, the static ripple voltage is less than 9mV, the power bandwidth could be 5kHz, the continuous output current could be 1.5A, the voltage variation is less than 0.01％ after eight hours continuous working. The volume of power supply is only 280*260*120mm, the power supply could satisfy the requirements of PZT driving.

This paper has summarized the current ranking method for interval-valued intuitionistic fuzzy numbers, and then through the introduction of decision-makers’ mentality indicator, presented a new ranking method for interval-valued intuitionistic fuzzy numbers based on mentality function. Not only the nature of mentality function is deeply discussed but also the decision-making model based on the interval-valued intuitionistic fuzzy numbers is constructed. At last, an example is illustrated to prove the model's accuracy and effectiveness.

Multi-Sinks wireless sensor networks, a current research focus, has better stability and effectiveness compared to the traditional single-SINK structure. To solve the problem how to complete the tasks within the possibly shortest time, a task scheduling algorithm(DMTA) based on divisible load theory in multi-Sinks wireless sensor networks is proposed. In DMTA, the tasks are distributed to wireless sensor network based on the processing and communication capacity of each sensor by multiple Sinks respectively. By removing communications interference between each sensor, reduced task completion time and improved network resource utilization achieved. Simulation results show that DMTA reasonably distributes tasks to each node in wireless sensor networks, and effectively reduces the time-consuming of task completion.