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Megaripples from the Mesoproterozoic of the Kimberley region,northwestern Australia and its geological implications

Journal of Palaeogeography 2012年第1期1卷 15-25页

作者： Lan Zhongwu 1,2,3,,Zhong-Qiang Chen 2,4,1.State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of sciences,Beijing 100029,china 2.school of Earth and Environment,The university of Western Australia,Australia 3.Key Lab of Petroleum Resources Research,Institute of Geology and Geophysics,Chinese Academy of sciences,Beijing 100029,china 4.State Key Laboratory of Biogeology and Environmental Geology,china university of Geosciences (Wuhan),Wuhan 430074,china State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China school of Earth and Environment The University of Western Australia Australia Key Lab of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences (Wuhan) Wuhan 430074 China

Large ripples are described from the Mesoproterozoic Hilfordy Formation in the Kimberley region,northwestern *** ripple index (RI) and ripple symmetry index (RSI) suggest the Kimberley ripples were likely generated by storm *** wave height is up to 15 23 cm and wave length is up to 70 90 *** features,incorporated with other morphological characteristics such as symmetry,steepness,ripple spacing,and compositions,agree well with the megaripples previously reported from the intertidal-nearshore settings of modern seas and the geological *** Mesoproterozoic ripples were likely generated by the storm-induced *** survey of the global record of megaripples reveals that such structures have occurred through the geological past from the Archean to present *** were particularly common in the Neoproterozoic and had the largest ripple length and ripple height among the modern and geological *** is probably because extreme storms prevailed at that *** frequent occurrence in present day beach is probably due to the prevalence of extreme storms caused by the monsoon or tsunami/earthquake influenced climatic regimes.

关键词： megaripples palaeohydrodynamics extreme storms Mesoproterozoic Hilfordy Formation Kimberley northwestern Australia

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Dynamic equivalent method of interconnected power systems with consideration of motor loads

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Science china(Technological sciences) 2010年第4期53卷 902-908页

作者： ZHOU HaiQiang1,JU Ping1,YANG Hui1 & SUN Ran2 1 Electrical Engineering school,HoHai university,Nanjing 210098,china 2 Henan Power Dispatching & Communication Center,Zhengzhou 450052,china Electrical Engineering school HoHai University Nanjing China Henan Power Dispatching & Communication Center Zhengzhou China

The existing equivalent methods usually only deal with static load models and neglect the dynamic characteristics of loads such as induction *** paper presents a dynamic equivalent method which considers motor *** first,the clustering criterion of motor loads is *** motors with similar dynamic characteristics are classified into one ***,reduction of motors in the same group is carried ***,parameters of the equivalent motor are calculated and the equivalent system is thus *** aggregation method is applied to the New England system of 39-buses and *** results show that the equivalent system retains the dynamic performance of the original system with good *** with the 1-motor equivalent scheme,the 2-motor equivalent scheme can improve equivalent precision effectively.

关键词： power system dynamic equivalent load model induction motor

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HYDRODYNAMIC ANALYSIS AND SIMULATION OF A SWIMMING BIONIC ROBOT TUNA

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Journal of Hydrodynamics 2007年第4期19卷 412-420页

作者： CHEN Hong ZHU Chang-an YIN Xie-zhen XING Xiao-zheng CHENG Gang College of Mechatronics and Control Engineering Shenzhen University Shenzhen 518060 China school of Engineering Science University of Science and Technology of China Hefei 230027 China

A dynamic model for undulatory locomotion was proposed to study the swimming mechanism of a developed bionic robot tuna. On the basis of inviscid hydrodynamics and rigid-body dynamics, the momentum and propulsive force required for propelling the swimming robot tuna＇s flexible body was calculated. By solving the established dynamic equations and efficiency formula, the swimming velocity and propulsive efficiency of the bionic robot tuna were obtained. The relationship between the kinematic parameters of the robot tuna＇s body curve and the hydrodynamic performances was established and discussed after hydrodynamic simulations. The results presented in this article can be used to increase the swimming speed, propulsive thrust, and the efficiency of underwater vehicles effectively.

关键词： undulatory locomotion swimming propulsive force efficiency body curve hydrodynamic simulations

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Unmanned air/ground vehicles heterogeneous cooperative techniques:Current status and prospects

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Science china(Technological sciences) 2010年第5期53卷 1349-1355页

作者： DUAN HaiBin & LIU SenQi National Key Laboratory of Science and Technology on Holistic Flight Control,school of Automation Science and Electrical Engineering,Beijing university of Aeronautics and Astronautics,Beijing 100191,china National Key Laboratory of Science and Technology on Holistic Flight Control School of Automation Science and Electrical Engineering Beijing University of Aeronautics and Astronautics Beijing China

Multiple unmanned air/ground vehicles heterogeneous cooperation is a novel and challenging *** cooperative techniques can widen the application fields of unmanned air or ground vehicles,and enhance the effectiveness of implementing detection,search and rescue *** paper mainly focused on the key issues in multiple unmanned air/ground vehicles heterogeneous cooperation,including heterogeneous flocking,formation control,formation stability,network control,and actual *** main problems and future directions in this field were also analyzed in *** innovative technologies can significantly enhance the effectiveness of implementing complicated tasks,which definitely provide a series of novel breakthroughs for the intelligence,integration and advancement of future robot systems.

关键词： unmanned air vehicle(UAV) unmanned ground vehicle(UGV) heterogeneous cooperation

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EXPERIMENT ON THE CHARACTERISTICS OF 3-D VORTEX RING BEHIND A FLEXIBLE OSCILLATING CAUDAL FIN

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Journal of Hydrodynamics 2010年第3期22卷 393-401页

作者： WANG Zhi-dong LAO Yi-jia LI Li-jun CONG Wen-chao school of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China Technology Research Economy Development Institute B eijing 10081 China school of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China

A test for the wake vortex of a flexible oscillating caudal fin is carried out with Digital Particle Image Velocimetry （DPIV）, and the variation of vortex distance and the vorticity in the range of oscillating frequency from 0.704 Hz to 1.17 Hz are analyzed. It is found that with the increase of the oscillating frequency, the vortex distance decreases and the peak of the vorticity increases, When the Strouhal number is smaller than 0.49, a larger thrust component is obtained. The distribution of the velocity circulation and the vortex distance in the different spanwise section of the caudal fin are given, and then the dimension of the vortex ring is determined. The radius of the vortex ring is 79.3 mm and the average velocity circulation is 28152.9 mm2/s at the oscillating frequency of 0.835 Hz. The model of 3-D vortex ring chain of flexible oscillating caudal fin is constructed based on the information of wake vortex field. Finally, an effective analysis method is provided for establishing the relationship of oscillating parameters for the caudal fin and the wake structure and the intrinsic mechanism of efficient fish swimming is investigated.

关键词： Digital Particle Image Velocimetry (DPIV) flexible caudal fin flow field vortex ring

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The Marxist View of Equity:Basic Dimensions and Methodological Principles

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Social sciences in china 2012年第1期33卷 23-37页

作者：马俊峰 school of Philosophy Renmin University of China

In the wide ranging discussion of social equity issues, the theories of contemporary Western thinkers such as Rawls, Nozick, Hayek and MacIntyre are repeatedly cited and expounded. By contrast, for various reasons, classical writers like Marx and Engels have been overlooked or even forgotten. Without a concrete analysis of their historical background and context, it is hard to grasp the true attitude and spiritual essence of the views of Marx and Engels on social equity. We might even conclude not only that they had no theory of social equity but that they opposed and rejected approaching questions from this angle. As a world view and methodology enabling the proletariat to know and transform the world and liberate themselves and mankind, Marxism is a theory that unites truth and value. A rational understanding of the issue of equity as an expression of value is only possible when the dimensions of science and value are dialectically combined. On the one hand, equity is a value concept that functions as a standard for evaluation; on the other, it refers to an actual state of values distribution (including interests, opportunities and rights) that inevitably involves the contradiction between freedom and equality and between formal and substantive equity, the difference between the general and the specific, the conflict between equality and efficiency, the opposition between equity and inequity and so on. Only a dialectical mode of thinking can ensure a correct understanding of the complexity of social equity issues.View full textDownload full text

关键词： social equity view of equity value stance

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TOTAL　SYNTHESIS　OF　CURVULARIN－TYPE　MACROLIDES　12－OXOCURVULARIN　AND　CITREOFURAN

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Chinese Chemical Letters 1994年第6期5卷 481-484页

作者： Sheng LAI and Xiang GAO (school of Pharmacy, West china university of Medical sciences, Chengdu 610041)Yoshikazu SHIZURI and Shosuke YAMAMURA (Department of Chemistry, Faculty of Science and Technology,Keio university, Hiyoshi, Yokohama 223, Japan)

The total synthesis of curvularin-type macrolides 12-oxocurvularin (1) and citreofuran (2) has been described. And the, stereostructures of the two macrolides are unambiguously confirmed by this synthesis.

关键词： TOTAL SYNTHESIS OF CURVULARIN CITREOFURAN AND

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Case Based Reasoning Intelligent System for Network Computer Aided Process Planning

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武汉理工大学学报 2006年第S3期28卷 1077-1080页

作者： ZHAO Chunhua WU Zhengjia ZHOU Chengjun ZHU Dalin LI Haoping school of Mechanical and Material,china Three Gorges university,Yichang 443002,china, school of Mechanical and Material China Three Gorges UniversityYichang 443002China

Computer aided process planning system played a key role for integrating design and manufacturing or assembly systems properly considering available resources and design *** take advantage of the enterprise resource,the web CAPP framework was *** based reasoning and multi agent system were integrated in the *** multi agent mecha- nism was discussed in the *** an instance of case base was *** made the system run independently and contin- uously in the network environment of process planning problems.

关键词： computer aided process planning multi agent system case based reasoning

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The voltage-current relationship and equivalent circuit implementation of parallel flux-controlled memristive circuits

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Chinese Physics B 2013年第6期22卷 621-626页

作者：包伯成冯霏董伟潘赛虎 school of Information Science and Engineering Changzhou University

A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example, upon which the voltage-current relationships （VCRs） between two parallel memristive circuits - a parallel memristor and capacitor circuit （the parallel MC circuit）, and a parallel memristor and inductor circuit （the parallel ML circuit） - are investigated. The results indicate that the VCR between these two parallel memristive circuits is closely related to the circuit parameters, and the frequency and amplitude of the sinusoidal voltage stimulus. An equivalent circuit model of the memristor is built, upon which the circuit simulations and exper/mental measurements of both the parallel MC circuit and the parallel ML circuit are performed, and the results verify the theoretical analysis results.

关键词： flux-controlled memristor memristor and capacitor (MC) circuit memristor and inductor (ML)circuit equivalent circuit

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Advances in Thermionic Cathode of Tungsten and Molybdenum

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Rare Metals 2001年第3期20卷 137-141页

作者： Jinshu Wang,Meiling Zhou, Tieyong Zuo, Juan Liu, Jiuxing Zhang, Zuoren Nie The Key Laboratory of Advanced Functional Materials, Ministry of Education, school of Materials Scence and Engineering, Beijing Polytechnic university, Beijing 100022, china 北京工业大学教育部新型功能材料重点实验室北京 100022.

Several kinds of tungsten thermonic cathodes have been introduced. As a promising alternative for thoriated tungsten, rare earth doped molybdenum cathode has been studied. Compared with the traditional thoriated tungsten, La-Mo cathode has higher emission current density at lower temperature, but it has poor emission stability. In order to improve the emission stability, systematical study on the emission mechanism of La-Mo cathode has been carried out. The life of La-Mo cathode has been improved and has achieved 1400 It, which exceeds the minimum life for practical uses (1000 h). As another alternative for thoriated tungsten cathode, Y-Mo cathode has shown better performance. The thermionic emission capability of Y-Mo cathode is between that of La-Mo cathode and Th-W cathode.

关键词： tungsten molybdenum thermonic cathode emission

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