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MODELING SEDIMENT PROCESSES ON SMALL WATERSHEDS: A CONCEPTUAL FRAMEWORK Ⅱ. CONCENTRATED FLOW PROCESSES

International Journal of Sediment Research 1993年第1期 1-23页

作者： Vicente L. LOPES and Peter F. FFOLLIOTT Assistant Professor, School of Renewable Natural Resources, The University of Arizona. tucson. Arizona. 85721 Professor, School of Renewable Natural Resources. The University of Arizona, tucson. Arizona. 85721

A general modeling framework is presented for developing sediment process models by concentrated flow systems on small watersheds. A survey of fundamental principles for developing sediment process models is made with particular emphasis on the effects of space and time averaging on the governing equations. Starting from the most general one-dimensional. unsteady model of sediment processes, simpler model structures are obtained and the successive simplifications made on the governing equations in order to obtain simpler and less detailed formulations are described. Examples of computer implementations of the different approaches using specific formulations are given. Al-though some progress has been made in modeling sediment processes by concentrated flow on small watersheds. the development of improved modeling approaches should be based on better understanding of runoff mechanisms and sediment processes as functions of space and time scales over a wide range of climatic and land-use conditions. Identification and quantification of differences and similarities of watershed behavior remain important and active areas of experimental research on process-based sediment modeling. Future research priorities in the area of runoff and sediment process modeling must address the development of boundary conditions; model components (system complexity); the scales over which the equations are valid: and integration of the equations in space and time.

关键词： Erosion and sediment yield Upland watersheds Concentrated flow processes conceptual modeling framework Governing equations Space-time averaging.

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INVESTIGATION ON CONTROL OF CHAOS

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Chinese Journal of Aeronautics 1997年第3期10卷 74-79页

作者： Yu Jianzu (Dept. of Flight Vehicle Design and Applied Mechanics, Beijing University of Aeronautics and Astronautics, Beijing, 100083, China) T. L. Vincent (The University of Arizona, tucson, AZ85721, USA)

The Lorenz system is a famous and typical chaotic system. This paper investigates the design of a linear feedback controller for the Lorenz system. By adjusting the gains used in the feedback control law the controller is able to produce stable motion which may contain apparent short (or intermediate ) term chaotic motion. In particular, using the control method, one can eliminate the effect of initial conditions on the indeterminateness of the motion and drive the chaotic system to a specified equilibrium state.

关键词： chaos control linearity feedback control

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有效控制白光LED电流的开关稳压器

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电子设计技术 EDN CHINA 2006年第7期13卷 103-103,106页

作者： Clayton B Grantham Agtech tucson Agtech TucsonAZ

无数年前．制造商们还将自己白光LED而不是暗淡LED的最大正向额定电流设定为20mA。今天的白光LED可以提供更高的亮度．因此必须工作在更高的偏置电流下。在接近LED最大额定值的大电流工作情况下仍要保持对LED偏置点的控制．就需要一种... 详细信息

无数年前．制造商们还将自己白光LED而不是暗淡LED的最大正向额定电流设定为20mA。今天的白光LED可以提供更高的亮度．因此必须工作在更高的偏置电流下。在接近LED最大额定值的大电流工作情况下仍要保持对LED偏置点的控制．就需要一种新的方法。

关键词：白光LED 额定电流开关稳压器最大额定值偏置电流偏置点大电流

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Application of Stochastic Fracture Network with Numerical Fluid Flow Simulations to Groundwater Flow Modeling in Fractured Rocks

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Journal of China University of Geosciences 2001年第3期12卷 240-248页

作者： Wang Mingyu The University of Arizona, tucson, Arizona, USA 85721 Department of Water Resources and Environmental Engineering, China University of Geosciences, Beijing 100083Chen Jinsong Wan Li Department of Water Resources and Environmental Engineering The University of Arizona Tucson Arizona USA 85721 Department of Water Resources and Environmental Engineering China University of Geosciences Beijing 100083 Department of Water Resources and Environmental Engineering China University of Geosciences Beijing 100083

The continuum approach in fluid flow modeling is generally applied to porous geological media, but has limited applicability to fractured rocks. With the presence of a discrete fracture network relatively sparsely distributed in the matrix, it may be difficult or erroneous to use a porous medium fluid flow model with continuum assumptions to describe the fluid flow in fractured rocks at small or even large field scales. A discrete fracture fluid flow approach incorporating a stochastic fracture network with numerical fluid flow simulations could have the capability of capturing fluid flow behaviors such as inhomogeneity and anisotropy while reflecting the changes of hydraulic features at different scales. Moreover, this approach can be implemented to estimate the size of the representative elementary volume (REV) in order to find out the scales at which a porous medium flow model could be applied, and then to determine the hydraulic conductivity tensor for fractured rocks. The following topics are focused on in this study: (a) conceptual discrete fracture fluid flow modeling incorporating a stochastic fracture network with numerical flow simulations; (b) estimation of REV and hydraulic conductivity tensor for fractured rocks utilizing a stochastic fracture network with numerical fluid flow simulations; (c) investigation of the effect of fracture orientation and density on the hydraulic conductivity and REV by implementing a stochastic fracture network with numerical fluid flow simulations, and (d) fluid flow conceptual models accounting for major and minor fractures in the 2 D or 3 D flow fields incorporating a stochastic fracture network with numerical fluid flow simulations.

关键词： discrete fracture fluid flow approach fractured rocks hydraulic conductivity tensor major fractures minor fractures numerical fluid flow simulations representative elementary volume stochastic fracture network.

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Response of Cytoskeleton of Murine Osteoblast Cultures to Two-step Freezing

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Acta Biochimica et Biophysica Sinica 2005年第12期37卷 814-818页

作者： Bao-Lin LIU~1 John McGRATH~21 Institute of Cryobiology,University of Shanghai for Science and Technology,Shanghai 200093,China 2 Department of Aerospace and Mechanical Engineering,University of Ariona,tucson 85721,USA InstituteofCryobiology UniversityofShanghaiforScienceandTechnologyShanghai200093China

Understanding the ultrastructural response of cells to the freezing process is important fordesigning cryopreservation strategies for cells and *** cellular structures of attached cells are targetsof cryopreservation-induced *** fluorescence staining was used to assess the status of theactin filaments (F-actin) of murine osteoblasts attached to hydroxyapatite discs and plastic coverslips for atwo-step freezing *** F-actin of dead cells was depolymerized and distorted in the freezing *** that of live cells had little *** results suggest that the cytoskeleton may support the robustnessof cells during *** present study helps to investigate the damage mechanism of attachedcells during the freezing process.

关键词： cytoskeleton osteoblast actin filament two-step freezing

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Confocal microscopic evaluation of cornea after AquaLase liquefaction cataract extraction

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International Journal of Ophthalmology(English edition) 2011年第3期4卷 293-297页

作者： Jiang-Yue Zhao 1,Ming-Wu Wang 2,Qi Sun 1,Jin-Song Zhang 1 1 Eye Hospital of China Medical University Department of Ophthalmology,the Fourth Affiliated Hospital of China Medical University Provincial Key Laboratory of Lens Research,Liaoning,China 2 Department of Ophthalmology and Vision Science,the University of Arizona,tucson,Arizona,USA Eye Hospital of China Medical University Department of Ophthalmology the Fourth Affiliated Hospital of China Medical University Provincial Key Laboratory of Lens Research Liaoning China Department of Ophthalmology and Vision Science the University of Arizona Tucson Arizona USA

AIM: The most recent and innovative AquaLase liquefaction technology has offered an alternative to lens extraction. Many studies have investigated its functions and advantages. This article focuses on evaluating the vivo microscopic cornea changes after AquaLase liquefaction by using a laser confocal microscope. METHODS: In this perspective, randomized case study, 37 eyes of 35 patients submitted to cataract surgery were chosen to undergo AquaLase liquefaction cataract extraction. Each patient was assessed before the operation, on the 1(st), 7(th), and 30(th) postoperative days, and 6 months after the cataract extraction. The morphologies and quantitative comparisons of corneal cells and corneal nerves layer by layer were evaluated in vivo with the Heidelberg Retina Tomograph III-Rostock Cornea Module (HRT-III RCM) confocal microscope. ANOVA and Post-Hoc Bonferroni test were carried out to compare the results pre- and post-operation. RESULTS: ANOVA results indicated no post-operation changes for epithelium and anterior stroma cells. Irregular segments of sub-basal nerve fiber were most pronounced seven days post-operation. In the mid and posterior stroma, keratocytes were obvious compared with the preoperative condition. Corneal endothelium cells became obviously swollen in cytoplasm and nucleus. The mid and posterior stroma cell density decreased from the 1(st) to 7(th) postoperative days (P < 0.05). The corneal endothelium cell density decreased (P < 0.05) and did not revert to the preoperative level after six months (P < 0.05). CONCLUSION: Slight microstructural abnormalities were identified in the corneal recovery process after AquaLase liquefaction. AquaLase liquefaction cataract extraction is safe for cornea.

关键词： aquaLase liquefaction cataract cornea changes

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OPTIMAL CONTROL AND DESIGN OF FLEXIBLE MANIPULATORS BASED ON LQR OUTPUT FEEDBACK

OPTIMAL CONTROL AND DESIGN OF FLEXIBLE MANIPULATORS BASED ON...

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2006年中国机械工程学会年会暨中国工程院机械与运载工程学部首届年会

作者： TU Li*, ZHOU Pixuan, DENG Jinlian* *Zhejiang Mechanical&Electrical College, Hangzhou, Zhejiang Province, China University of Arizona, tucson, AZ 85721,USA,

The construction of lightweight manipulators with a larger speed range is one of the major goals in the design of well-behaving industrial robotic arms. Their use will lead to higher productivity and

关键词： Mechatronic design flexible manipulators optimisation.

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WATERSHED SEDIMENT YIELD AND RANGELAND HEALTH

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International Journal of Sediment Research 2000年第1期15卷 51-59页

作者： Leonard J. Lane Mary R. Kidwell and Mark A. Weltz(Authors are hydrologist, ecologist and hydrologist, respectively, at the USDA-ARS Southwest Watershed Research Center, 2000 E. Allen Rd., tucson, AZ 85719Note: The manucript of this paper was received in

Much of the western United States is considered to be rangeland. Rangeland areas produce a diverse mix of benefits and products, and their overall health, in an ecosystem context, is of national *** sediment yield from a watershed is an integrated expression of all soil erosion and sedimentation processes occurring within it, it is logical that we seek to quantify and interpret sediment yield in the context of soil/site stability and watershed function as measures of rangeland health. Depth integrated suspended sediment samples were combined with runoff measured using flumes to calculate sediment discharge and yield from two experimental watersheds in the southwestern USA. Sediment yield estimates for individual runoff events were summed to produce estimates of annual sediment yield from these two rangeland watersheds. Estimated annual sediment yield data were then combined with the concepts of sediment delivery ratio and soil loss tolerance to assess soil/site stability at the watershed scale. Analyses suggest that using sediment yield estimates from distributed watershed processes with time-space averaged soil loss tolerance values is inconsistent. Thus, new distributed soil/site stability criteria are needed to replace the soil loss tolerance concept in assessing the health of rangeland watersheds. Sediment transport/yield models are used at interior points in a watershed to simulate distributed sedimentation processes. However, application of these models requires calibration and validation data and is thus dependent upon the availability of sediment concentration and yield databases. Therefore, additional efforts are required to build sediment yield databases through rescue of historical data along with continued measurement and monitoring at existing and new sampling sites.

关键词： Sediment yield Rangalang health Ecosystem contex Sedimentation processes Sediment delivery ratio

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GRANITOIDS,VOLCANIC ROCKS AND CHERTS FROM NORTH ALTYN TAGH,NW CHINA: IMPLICATION FOR THE TECTONIC ENVIRONMENT DISCRIMINATION

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地学前缘 2000年第S1期7卷 249-250页

作者： Chen Xuanhua\+1,Wang Xiaofeng\+1,Chen Zhengle\+1,George Gehrels\+2,Yin An\+3[WT5,5”BX](1.Institute of Geomechanics,CAGS,Beijing 100081,China 2.Department of Geosciences, University of Arizona,tucson,AZ 85721,USA 3.Department of Earth and Space Science

Granitoids,volcanic rocks and cherts,mainly of early Paleozoic,in northern Altyn Tagh(Fig.1) are analyzed here for the purpose of the determination of the tectonic environments and their development since Early Paleozoic.(1) Granitoids\ The collection of 128 main\|element petrochemical data from North Altyn Tagh area shows that most of the granitoids here are granites and granodiorites of calc\|alkaline *** consist mainly of metaluminous and peraluminous in Shand’s index,and only one of them,which belongs to Mesozoic,is *** of the granitoids plot in the IAG+CAG+CCG fields in the Maniar and Piccoli’s diagrams (1989) for tectonic discrimination of *** (Island arc granitoids)and CAG (Continental arc granitoids) can be distinguished for Early and Late Paleozoic granitoids,and maybe some CCG (Continental collision granitoids) for Early *** of Mesozoic and Cenozoic inherited the characteristics of those of *** active plate margin (pre\|plate collision)and Anatectic magmatism(syn\|orogenic,S\|type granites)are distinguished (Fig.2)for Paleozoic granitoids using de la Roche R 1\| R 2 multicationic diagram (Batchelor and Bowden,1985).Mesozoic and Cenozoic granitoids inherited the characteristics of Anatectic magmatism (syn\|orogenic)of these early ones,and post\|orogenic(A\|type)granites occurred in *** mechanism for magma formation is mainly partial melting.

关键词： granitoids volcanic rocks cherts tectonic environ ment Altyn Tagh

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MODELING SEDIMENT PROCESSES ON SMALL WATERSHEDS:A CONCEPTUAL FRAMEWORK Ⅰ. BROAD SHALLOW FLOW PROCESSE

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International Journal of Sediment Research 1992年第3期 21-44页

作者： Vicente L. LOPES Assistant Professor, School of Renewable Natural Resources, The University of Arizona, tucson, Arizona, 85721 Peter F. FFOLLIOTT Professor, School of Renewable Natural Resources, The University of Arizona, 85721

A conceptual modeling framework for developing process-based mathematical models of sediment generation, transport, and deposition on broad shallow flow areas is presented. The governing equations relevant to process-based modeling of broad shallow flow sediment processes on small watersheds are presented and the effects of space and time averaging on the predictive equations are described. Starting from the most general one-dimensional, unsteady model of sediment processes, simpler model structures are obtained and the successive simplifications made on the governing equations in order to obtain simpler and less detailed formulations are described. Specific model formulations are given for illustrative purposes and applications of these models to erosion and sediment yield prediction from broad shallow flow areas are shown using sediment data from rainfall simulator plots. In spite of some progress made in the development of process-based erosion and sediment yield models from broad shallow flow areas, further developmental modeling efforts must be based on a clear separation between hydrologic and hydraulic processes, and the soil properties which are significant for each.

关键词： Erosion and sediment yield, Upland watersheds Broad shallow flow processes Conceptual modeling framework Governing equations Space-time averaging.

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