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Responses of distribution pattern of desert riparian forests to hydrologic process in Ejina oasis

Science china Earth Sciences 2004年第z1期47卷 21-31页

作者： ZHAO Wenzhi, CHANG Xueli & HE ZhibinLinze Inland River Basin Comprehensive Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, china yantai normal university, yantai 264005, china 1. Linze Inland River Basin Comprehensive Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences 730000 Lanzhou China2. Yantai Normal University 264005 Yantai China

By using the theories and methods of landscape ecology and the technology of GIS and RS, a study has been carried out on the responses of distribution pattern of desert riparian forest to hydrologic process on the basis of the hydrologic data from 1990 to 2000 and the TM image of 2001 year. The results showed that: (1) there appears an even distribution pattern for the relative forest area in oasis, however, the degenerated forest diaplays an increasing tendency from west to east; (2) the desert riparian forest in Ejina is in completely degenerated process at the patch scale; (3) the number of patch is influenced not only by hydrologic process,but also by agricultural activity such as cultivation. The severe deterioration of the degraded vegetation in whole oasis initiates from lower reaches, and gradually impels to upstream; the fragmentation of landscape in the terminal site is more obvious, which is influenced by river shape and decreasing flux of water. It is found that the influence of surface hydrologic process to the ground hydrologic process of desert riparian forest in Ejina oasis is little for the recent ten years. The relative area of the degenerated forest increased with increasing ground water depth in the direction of parallel to river channel. On the contrary, in the direction perpendicular to river channel, there is a decreasing tendency for the average patch area of the forest and the degenerated forest with increasing ground water depth.

关键词： Ejina oasis, desert riparian forests, vegetation pattern, hydrologic process.

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Prediction and Control of Both Wrinkle Limit and Fracture Limit on Cylindrical Cup Deep-Drawing

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International Journal of Minerals,Metallurgy and Materials 1998年第4期12卷 237-240,250页

作者： Junxiang Lei(Department of Mechanical Enginecring, yantai university, yantai264005,china) Department of Mechanical Engineering Yantai University Yantai 264005 China

hased on both the wrinkle model and fracturc model, the wrinkle critical tangent pressure and the fractureon critical radial tensile stress are calculated respectively. The maximum tangent pressure formula in the flange deformation zone and the maximum radial tensile stress formula in the cylinder-wall pass force zone are given, and both theno-wrinkle limitl criterion and no-fracture limit criterion are put froward. The prediction and control criterion anddiagram of both the wrinkle limit and fracture limit on cylindrical cup deep-drawing, the most suitable formingzone and the limit deep-drawing coefficient are obtained. Comparing with present experience formulae and actualproduct's production, this prediction and control are quite accurate.

关键词： cylindrical cup deep-drawing wrinkle limit fracture limit deep-drawing limit

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NOVEL METHOD OF REALIZING THE OPTIMAL TRANSMISSION OF THE CRANK-AND-ROCKERMECHANISM DESIGN

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Chinese Journal of Mechanical Engineering 2003年第1期16卷 31-33页

作者： Fang Shijie Li LiDepartment of Mechanical Engineering,yantai university,yantai 264005, china Department of Mechanical Engineering Yantai University Yantai 264005

A novel method of realizing the optimal transmission of the crank-and-rockermechanism is presented. The optimal combination design is made by finding the related optimaltransmission parameters. The diagram of the optimal transmission is drawn. In the diagram, therelation among mini-mum transmission angle, the coefficient of travel speed variation, theoscillating angle of the rocker and the length of the bars is shown, concisely, conveniently anddirectly. The method possesses the main characteristic. That it is to achieve the optimaltransmission parameters under the transmission angle by directly choosing in the diagram, accordingto the given requirements. The characteristics of the mechanical transmission can be improved togain the optimal transmission effect by the method. Especially, the method is simple and convenientin practical use.

关键词： Crank-and-rocker mechanism Optimal transmission angle Coefficient oftravel speed variation

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A MULTISTEP FINITE VOLUME METHOD WITH PENALTY FOR THERMAL CONVECTION PROBLEMS IN TWO OR THREE DIMENSIONS

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Journal of Systems Science & Complexity 2008年第1期21卷 129-143页

作者： Min YANG Department of Mathematics Yantai University Yantai 264005 China

The author considers a thermal convection problem with infinite Prandtl number in two or three dimensions. The mathematical model of such problem is described as an initial boundary value problem made up of three partial differential equations. One equation of the convection-dominated diffusion type for the temperature, and another two of the Stokes type for the normalized velocity and pressure. The approximate solution is obtained by a penalty finite volume method for the Stokes equation and a multistep upwind finite volume method for the convection-diffusion equation. Under suitable smoothness of the exact solution, error estimates in some discrete norms are derived.

关键词： Error estimate finite volume thermal convection problem unstructured meshes.

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A New Generating Method and Its Application

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Journal of Systems Engineering and Electronics 2003年第2期14卷 82-85页

作者： Song Zhongmin Dept. of Mathematics, yantai university, yantai 264005, P. R. china Dept. of Mathematics Yantai University Yantai 264005 P. R. China

In this paper, a new generating method-opposite-direction accumulated generating operation is presented. The effectiveness of the method for different original sequences to choose different generating operation is discussed and the optimal parameters ɑ and b of grey model by a new structure of background and initial value are obtained. Some properties of a grey model are studied. The calculating precision of the example shows that the method is very effective.

关键词： Sequence Generating method Grey model.

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Prediction and Control of both Wrinkle Limit and Fracture Limiton Cylindrical Cup Deep-drawing(Ⅱ)

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 201-204页

作者： Junxiang Lei Yonglin Kang(Department of Mechanical Engineering, yantai university, yantai 264005, china)(Material Science and Engineering School, university of Science and Technology Beijing, Beijing 100083, china) Department of Mechanical Engineering Yantai University Yantai 264005 China Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The prediction and control criterion of both the wrinkle limit and fracture limit on the cylindrical cup deep-drawing are given, and the prediction and control diagram of both the wrinkle limit and fracture limit are also given. The results show that it is suitable for no-flange cylindrical cup deep-drawing, narrow-flange cylindrical cup deep-drawing, wide-flange cylindrical cup deep-drawing/expanding compound forming and rigid punch expanding forming.

关键词： cylindrical cup wrinkle limit fracture limit deep-drawing expanding forming compound forming

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Study on Green Residential Space Design

IJLAI Transactions on Science and Engineering

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IJLAI Transactions on Science and Engineering 2024年第1期2卷 32-37页

作者： Yu Jiang Shenyang normal university No.253 Huanghe North Street Shenyang 110034China

With the ever-changing nature,green ecology has become an international trend of ***,the green ecological design of residential space has become the main melody of people’s *** always implement the concept of ecological and environmental protection in the design process,attach importance to the ecological effect of residential space,carry out reasonable budget and use of environmentally friendly decorative materials,reduce the waste of materials,save money and save resources at the same time,and protect the *** the same time,people began to put their hopes on the residential space design,which made the green residential space design began to *** the bold exploration and practice of designers,the design of green residential space will be endowed with more distinctive characteristics and unique *** from the concept of green design,this paper explores the method of green space design through typical analysis.

关键词： Green Residential space Haze

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Calculations of Chemical Reaction Dynamics for D+ H_2(j_i,ν_i=0)→DH(j_f, ν_f=0) + H

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Chinese Chemical Letters 1997年第2期8卷 153-156页

作者： Li Qin SI(Editorial Office of Natural Science, yantai normal university, yantai, 264025) Editorial Office of Natural Science Yantai Normal University Yantai 264025 China

The constant Centrifugal potential approximation is Corrected so as to apply to the reactions of rotational excited reactants for D + H2 (j,, νi = 0 ) -DH(jf, νf = 0) + H. Our results show that the contributions fro... 详细信息

关键词： DH j_f H2 j_i i=0 Calculations of Chemical Reaction Dynamics for D

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Investigati on sonsimultaneous determination of silver and mercury in catalytic－ligandsub stitution reaction with stopped－flow technique calibrated by synergistic effect

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Journal of Environmental Sciences 1995年第4期7卷 414-421页

作者： Wang Jianhua , He Ronghuan(Chemistry Department of yantai normal College, yantai 264025 , china)

Ｉｎｖｅｓｔｉｇａｔｉｏｎｓｏｎｓｉｍｕｌｔａｎｅｏｕｓｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｓｉｌｖｅｒａｎｄｍｅｒｃｕｒｙｉｎｃａｔａｌｙｔｉｃ－ｌｉｇａｎｄｓｕｂｓｔｉｔｕｔｉｏｎｒｅａｃｔｉｏｎｗｉｔｈｓｔｏｐｐｅｄ... 详细信息

Ｉｎｖｅｓｔｉｇａｔｉｏｎｓｏｎｓｉｍｕｌｔａｎｅｏｕｓｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｓｉｌｖｅｒａｎｄｍｅｒｃｕｒｙｉｎｃａｔａｌｙｔｉｃ－ｌｉｇａｎｄｓｕｂｓｔｉｔｕｔｉｏｎｒｅａｃｔｉｏｎｗｉｔｈｓｔｏｐｐｅｄ－ｆｌｏｗｔｅｃｈｎｉｑｕｅｃａｌ...

关键词： kinetic stopped FIA synergistic catalytic coefficient simultaneous determination mercury(II) silver(I).

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The influence of laser pulse on the photoabsorption spectra of Li atom in strong external field

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Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1 & LIN Shenglu2 1. School of Physics and Electronic Engineering, yantai normal university, yantai 264025, china 2. Department of Physics, Shandong normal university, Jinan 250014, china 1. School of Physics and Electronic Engineering Yantai Normal University Yantai 264025 China 2. Department of Physics Shandong Normal University Jinan 250014 China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

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