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On minimum cavitation number of the ventilated supercavity in water tunnel

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Science China(Physics,Mechanics & Astronomy) 2013年第10期56卷 1945-1951页

作者： zou wang YU KaiPing ARNDTREA KAWAKAMIE The School of Astronautics Harbin Institute of Technology Saint Anthony Falls Laboratory University of Minnesota

A numerical method consisted of the cavitation number correction and the model coefficient correction algorithms is presented to simulate the supercavity in water tunnel considering blockage and gravity effects based on the Logvinovich model.A model of the minimum cavitation number is also proposed based on the dimensional analysis theory,and the minimum cavitation number is formulated based on the model and numerical results using the nonlinear least square method(NLLS).The formula is verified by experiment to some extent.

关键词： supercavity minimum cavitation number Froude number blockage ratio NLLS

SUPERCAVITY MOTION WITH INERTIAL FORCE IN THE VERTICAL PLANE

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Journal of Hydrodynamics 2012年第5期24卷 752-759页

作者： YU Kai-ping zou wang ARNDT Roger ZHANG Guang School of Astronautics Harbin Institute of TechnologyHarbin 150001China Saint Anthony Falls Laboratory University of MinnesotaMinneapolisUSA

The curvilinear motion in a vertical plane is one of the most important features of the supercavitating vehicle. It is of great significance to study the controllability and the maneuverability of the supercavitating vehicle. Models are built for the effects of the angle of attack, the gravity and the inertial force in the curvilinear motion in the vertical p｜ane. Numerica~ simulations are carried out for the supercavity motion based on these models combined with the Logvinovich model. It is shown that the maximum deviation displacement in the outward normal direction of the trajectory with a constant curvature, which occurs in the tail of the supercavity, increases as the cavitation number or the curvature radius of the supercavity trajectory decreases under the condition that other model and flow parameters are kept constant. For a varied curvature, the supercavity shape changes evidently because of the change of the ambient pressure, but with the same trend as in constant curvature. The deviation displacement increases along the supercavity length gradually.

关键词： supercavity inertial force curvilinear motion curvature radius

High performance liquid chromatographic separation of clausenamide enantiomers with chiral-AGP stationary phase

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Chinese Chemical Letters 2010年第7期21卷 860-863页

作者： Yan wang Qing Qiang Yao Mu zou wang Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical CollegeBeijing 100050China Institute of Materia Medica Shandong Academy of Medical ScienceJinan 250062China

A method of high performance liquid chromatographic separation of clausenamide enantiomers with chiral-AGP（α_1-acid glycoprotein） stationary phases has been *** absolute configurations of（-）clausenamide and（＋）clausenamide are 3S, 4R,5R,6S and 3R,4S,5S,6R,*** present method has been used to analyze the（-）clausenamide and（＋）clausenamide and its analogues such as the major metabolite and synthetic derivatives of clausenamide.

关键词： Enantiomers (-)Clausenamide (+)Clausenamide Chiral-AGP HPLC

NUMERICAL STUDY OF THE PITCHING MOTIONS OF SUPERCAVITA-TING VEHICLES

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Journal of Hydrodynamics 2012年第6期24卷 951-958页

作者： YU Kai-ping ZHANG Guang ZHOU Jing-jun zou wang LI Zhen-wang School of Aeronautics Harbin Institute of Technology

The pitching motions of supercavitating vehicles could not be avoided due to the lost water buoyancy. In order to have some insight for the design of the supercavitating vehicles, the fixed frequency and free pitching motions are investigated. A numerical predicting method based on the relative motion principle and the non-inertia coordinate system is proposed to simulate the free pitching motions of supercavitating vehicles in the longitudinal plane. Homogeneous and two fluid multiphase models are used to predict the natural and the ventilated supercavitating flows. In the fixed frequency pitching motions, a variety of working conditions are considered, including the pitching angular velocities and the supercavity scales and the results are found to be consistent with the available experimental results in literature. The mesh deformation technology controlled by the moment of momentum equation is adopted to study the free pitching motions and finally to obtain the planing states proposed by Savchenko. The numerical method is validated for predicting the pitching motions of supercavitating vehicles and is found to enjoy better calculation efficiency as comparing with the mesh regeneration technology.

关键词： supercavitating flow two fluid multiphase flow model homogeneous model pitching motion mesh deformation

Comparison of Present SST Gravity Field Models

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Geo-Spatial Information Science 2006年第3期9卷 175-179页

作者： LUO Jia SHI Chuang zou Xiancai wang Haihong School of Geodesy and Geomatics Wuhan University 129 Luoyu Road Wuhan 430079 China

Taking the main land of Europe as the region to be studied, the potential of the new satellite gravity technique: satellite-to-satellite tracking (SST) and improving the accuracy of regional gravity field model with the SST models are investigated. The drawbacks of these models are discussed. With GPM98C as the reference, the gravity anomaly residuals of several other models, the latest SST global gravity field models (EIGEN series and GGM series), were computed and compared. The results of the comparison show that in the selected region, some systematic errors with periodical properties exist in the EIGEN and GGM’s S series models in the high degree and order. Some information that was not shown in the classic gravity models is detected in the low and middle degree and order of EIGEN and GGM’s S series models. At last, the effective maximum degrees and orders of SST models are suggested.

关键词： satellite-to-satellite tracking gravity field CHAMP GRACE

Time behavior of field screening effects in small-size GaAs photoconductive terahertz antenna

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Frontiers of Optoelectronics 2015年第1期8卷 98-103页

作者： Tianyi wang Zhengang YANG Si zou Kejia wang Shenglie wang Jinsong LIU Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China

The field screening effects in small-size GaAs photoconductive （PC） antenna are investigated via the well-known pump and probe terahertz （THz） generation technique. The peak amplitude of the THz pulses excited by the probe laser pulse as a function of the pump-probe time delay was measured. An equivalent-circuit model was used to simulate the experimental data. Based on the good agreement between the results of simulation and experiment, the time behavior of the radiation and space-charge fields was simulated. The results show that the spacecharge screening dominantly determines the device response in the whole time, while the radiation filed screening plays a key role in initial time which strongly affects the peak THz field. The parameter analysis was performed, which may be valuable on the optimum design for the antenna as a THz emitter.

关键词： GaAs photoconductive (PC) antenna field screening effects terahertz (THz) emitter

STRUCTURAL CHANGE IN HEAT AFFECTED ZONE AND ITS INFLUENCE ON PROPERTIES OF WELDED WHITE CAST IRON

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Acta Metallurgica Sinica(English Letters) 1991年第9期4卷 191-195页

作者： zou Zengda wang Yong REN Dengyi Shandong Polytechnic University,Jinan,China Shandong Polytechnic Univ Jinan China

The structural change in heat affected zone(HAZ)and its influence on properties of welded white cast iron have been investigated by means of thermal cycle simulation *** structure of the white cast iron at peak temperature 800℃ was examined as cementite in pearlitic matrix,of which the hardness and impact toughness are the lowest,while the struc- ture after cyclic heating at high peak temperature is mainly cementite together with twin martensite,of which the hardness and impact toughness are rather *** phase bounda- ries in the structure of low hardness are smooth and regular as well as with fine precipitates. Both the cleavage and interphase fracture were revealed in the structure of low hardness,while the transgranular fracture was found in those areas of higher hardness.

关键词： white cast iron heat affected zone simulation technique

Adaptive neuro fuzzy inference system for classification of water quality status

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Journal of Environmental Sciences 2010年第12期22卷 1891-1896页

作者： Han Yan,Zhihong zou,Huiwen wang School of Economics and Management,Beihang University,Beijing 100191,China School of Economics and Management Beihang University Beijing 100191 China

An adaptive neuro fuzzy inference system was used for classifying water quality status of river. It applied several physical and inorganic chemical indicators including dissolved oxygen, chemical oxygen demand, and ammonia-nitrogen. A data set （nine weeks, total 845 observations） was collected from 100 monitoring stations in all major river basins in China and used for training and validating the model. Up to 89.59% of the data could be correctly classified using this model. Such performance was more competitive when compared with artificial neural networks. It is applicable in evaluation and classification of water quality status.

关键词： adaptive neuro fuzzy inference system artificial neural networks water quality status classification

AN　EXTENSION　OF　CLARIAUT　EQUATION　AND　ITS　APPLICATION

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Applied Mathematics(A Journal of Chinese Universities) 1997年第1期12卷 3-16页

作者： LIANG YOUDONG zou ZHENQIANG AND wang GUOZHAO

Abstract The geodesic in differential geometry is commonly used in computer aided filament winding (CAFW) to avoid slippage in manufacturing process. The uniqueness of the geodesic by its initial values severely restricts the choice of the fiber path and is an obstacle to the production of optimized structures. This paper presents a new class of more flexible non slip trajectories on revolutional surfaces as an extension of the well known Clariaut equation and gives its application in CAFW.

关键词： ITS AN AND APPLICATION CLARIAUT EQUATION