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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.

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.

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.

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.

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.

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.

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.

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.

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.