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On the Solvability of Degenerate Quasilinear parabolic Equations of Second Order

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Acta Mathematica Sinica,English Series 2000年第2期16卷 313-324页

作者： Zhenhai Liu department of Mathematics,Changsha University of Electric power,Changsha 410077,p.r.china department of Mathematics Changsha University of Electic Power Changsha 410077 P. R. China

In this paper,we consider nonlinear degenerate quasilinear parabolic initial boundary value problems of second *** results from the theory of pseudomonotone operators,we show that there exists at least one weak soluti... 详细信息

关键词： Quasilinear parabolic Degenerate equation Existence result

Sufficient and Necessary Conditions for Stochastic Comparability of Jump processes

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Acta Mathematica Sinica,English Series 2000年第1期16卷 99-102页

作者： Yuhui Zhang department of Mathematics,Beijing Normal University,Beijing 100875,p.r.china department of Mathematics Beijing Normal University Beijing 100875 P.R. China

This note is devoted to the study of the stochastic comparability of jump *** the basis of[2]and[3],it is proved that two jump processes are stochastically comparable if and only if their q-pairs are ***,the result co... 详细信息

关键词： Stochastically comparable Totally stable Conservative Uniqueness

“有效降低全社会物流成本”研讨会专家观点综述

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中国流通经济 2024年第5期38卷 3-17页

作者：本刊编辑部《中国流通经济》编辑部

2024年2月24日,习近平总书记主持召开中央财经委员会第四次会议,指出物流是实体经济的“筋络”,强调必须有效降低全社会物流成本,增强产业核心竞争力,提高经济运行效率。基于此,2024年4月24日,北京物资学院党委宣传部、杂志社、科研处... 详细信息

2024年2月24日,习近平总书记主持召开中央财经委员会第四次会议,指出物流是实体经济的“筋络”,强调必须有效降低全社会物流成本,增强产业核心竞争力,提高经济运行效率。基于此,2024年4月24日,北京物资学院党委宣传部、杂志社、科研处联合主办了“有效降低全社会物流成本”研讨会。本次研讨会邀请我国流通物流领域的专家学者,围绕物流服务实体经济和人民群众、物流成本构成、交通运输体系改革、统一高效物流市场构建和现代商贸流通体系完善等问题,发表观点,为探索有效降低全社会物流成本可行路径,构建现代流通体系提供理论支持和实践指导。本刊编辑部对专家阐述的主要观点进行了归纳整理,以飨读者。

关键词：全社会社会物流成本新质生产力流通体系降本增效

research on fiber optic gyro signal de-noising based on wavelet packet soft-threshold

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Journal of Systems engineering and Electronics 2009年第3期20卷 607-612页

作者： Qian Huaming & Ma Jichen Coll.of Automation,Harbin engineering Univ.,Harbin 150001,p.r.china Coll. of Automation Harbin Engineering Univ. Harbin 150001 P. R. China

Gyro＇s drift is not only the main drift error which influences gyro＇s precision but also the primary factor that affects gyro＇s reliability. reducing zero drift and random drift is a key problem to the output of a gyro signal. A three-layer de-nosing threshold algorithm is proposed based on the wavelet decomposition to dispose the signal which is collected from a running fiber optic gyro （FOG）. The coefficients are obtained from the three-layer wavelet packet decomposition. By setting the high frequency part which is greater than wavelet packet threshold as zero, then reconstructing the nodes which have been filtered out noise and interruption, the soft threshold function is constructed by the coefficients of the third nodes. Compared wavelet packet de-noise with forced de-noising method, the proposed method is more effective. Simulation results show that the random drift compensation is enhanced by 13.1%, and reduces zero drift by 0.052 6°/h.

关键词： wavelet transform drift fiber optic gyro soft-threshold signal de-noising

The Application of Simulation Technique in Whole CIMS Life Cycle

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Journal of Systems engineering and Electronics 1994年第3期5卷 64-67,70-72页

作者： Xiong Guangleng and Guo Jianbo (department of Automation, Tsinghua University Beijing 1000084, p.r.china ) department of Automation Tsinghua University Beijing 1000084 P.R. China

The life cycle of CIMS (Computer Integrated Manufacturing System) includes four phases:requirement analyzing, designing, implementation and running. For reducing the risk of investment and achieving better economic results the simulation technique is needed in the above four phases of CIMS life cycle. Under the support of china 863/CIMS plan a series of simulation projects are established. Some of them are finished with succeed and have been used in application. In this paper four simulation projects are introduced.(1) The Integrated Manufacturing Simulation Software (IMSS). It is an integrated platform, based on the discrete event simulation principle. It can be used to analyze and design CIMS, especially FMS; and evaluate the daily production plan.(2) The Advanced Hierarchical Control System Emulator (AHCSE), a software system, based on the finite state machine principle. It can be used to analyze and design of CIMS hicrarchical control system, and check expanded system performance before expanding.(3) The Factory Scheduling Environment (FASE), a software system based on the discrete event simulation principle and artificial intelligence technology. It can be used for shop floor scheduling. (4) The Machining process Simulator (MpS). It can simulate the machining process of machining center by computer. It can check the correctness of NC code (including interference and confliction) and replace the real machining center to support the simulation environment for shop floor scheduling and controlling. There are three companies and universities joining in these four projects, they are: Tsinghua University,Huazhong University of Technology, Beliing Institute of Computer Application and Simulation.

关键词： Manufacturing systems Modeling and simulation CIAS life cycle.

Effects of plasma Nitriding on Microstructure and Tribological properties of CoCrMo Alloy Implant Materials

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Journal of Bionic engineering 2010年第4期7卷 337-344页

作者： Qingliang Wang,Lei Zhang,Jiandong Dong School of Material Science and engineering,china University of Mining & Technology,Xuzhou 221116,p.r.china School of Material Science and engineering China University of Mining & Technology Xuzhou P. R. China

Medical forged CoCrMo alloy was treated by plasma nitriding *** microstructures were characterized by 3Dprofiler,SEM and *** tribological properties were investigated under lubrication of 25% bovine serum *** that plasma nitriding is a promising process to produce thick,hard,and more wear resistant layers on the surface of *** nitrided samples showed an important increase in the surface hardness due to the formation of harder CrN andCrN phases with compact nano-crystalline *** typical hardness values of HVincreased almost two times thanuntreated *** bovine serum lubrication,at low nitriding temperature the Coefficient of Friction (COF) of nitrided samplewas lower than that of untreated sample,but at high nitriding temperature the COF was almost the same as the untreated *** with the untreated sample,the nitrided samples showed lower wear rates and higher wear resistance under differentnitriding *** adhesive wear is the main mechanism for untreated CoCrMo alloy and the wear mechanisms ofnitrided ones are the fatigue wear and slight adhesive *** is concluded that the improvement of wear resistance is ascribed tothe hard nitride formation of CrN and CrN phases at the nitrided surfaces.

关键词： CoCrMo alloy plasma nitriding microstructure friction and wear

A Method for Generating Super Large Fractal Images Useful for Decoration Art

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Communications in Nonlinear Science and Numerical Simulation 1996年第3期1卷 24-27页

作者： Huajie LIU Jun LUO(research Center for Science & Society peking University, p.r.china)(department of Computer Science & Technology, peking University, p.r.china) research Center for Science & Society Peking University P.R. China

Many authors have reported the techniques to iterate nonlinear equations oncomplex plane, but generally, the sise of image calculated by usual VGA style (640×480) istoo small to fit the needs for high quality publications or decorative patterus. We describea universal method for generating and storing (in *.GIF format) fractal forge large enoughas you need, such as an wie 5000×5000 256-color(25,000, 74 bytes 23.8MB), whichcan thoroughly display the intricate beauty of fractals.

关键词： super large fractal images iteration decoration art

Optical Beam Deflection Technique to measure Absorptivity distribution of Optical Thin Film

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光电子·激光 1989年第2期 111-113页

作者： Chen Wen-bin Huang Xue-boOptical engineering department Zhejiang University,p.r.china

Optical beam deflection (OBD) is a new and very useful technique in scientific research and industry. It has been used, for instance, in combution diagnostics to measure flowvolosity, temperature and concentration in a flame, in material science and industry to do non-destructive testing and measure thermal parameters and absorptivity. It is also a high sensitive spectroscopy when the wave-length seaning.

关键词： Optical Beam Deflection Technique to measure Absorptivity distribution of Optical Thin Film Thin

The Micro/Nanostructure Characteristics and the Mechanical properties of Hemifusus tuba Conch Shell

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Journal of Bionic engineering 2010年第4期7卷 3+308-313页

作者： Yan Liang~1,Jie Zhao~2,Chengwei Wu~1 1.State Key Laboratory of Structural Analysis for Industrial Equipment,department of engineering Mechanics,Dalian University of Technology,Dalian 116024,p.r.china 2.School of Materials Science and engineering,Dalian University of Technology,Dalian 116024,p.r.china State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian P. R. China School of Materials Science and engineering Dalian University of Technology Dalian P. R. China

The mollusk shell mobilizes calcium from environment for skeletal *** occurs through synthesizing solidsin solution in the presence of organic molecules of specific interior regions of the conch *** ultrastructure and microhardnessof the Hemifusus tuba conch shell living in the Huang/Bo sea area are investigated in the *** is shown that thecomposition and microstructure of the mollusk shell vary in different *** prodissoconch shell consists only of aragonitewith the crossed-lamellar *** the spiral shell and the body shell of the Hemifusus tuba conch shell arecomposed of one calcite layer and several aragonite *** calcite layer consists of cylindrical grains,but the aragonitelayers are crossed-lamellar ultrastructure at three size *** minimum structure size (the third-order lamella) is at about20 nm - 80 *** margin of shell aperture is only composed of calcite with cylindrical *** natural optimization of theshell microstructure is intimately due to the growth of the Organic *** different positions the microhardness of molluscshell is different due to different crystal structures and crystal *** growth process of shells allows a constantrenewal of the material,thus enabling their functional adaptation to external environments.

关键词： conch shell microstructure aragonite calcite crossed-lamellar