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The refined theory of deep rectangular beams for symmetrical deformation

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： GAO Yang1 & WANG MinZhong2 1 College of Science, china agricultural university, Beijing 100083, china 2 State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Aerospace engineering, Peking university, Beijing 100871, china College of Science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Aerospace engineering Peking University Beijing 100871 China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Spatial continuity incorporated multi-attribute fuzzy clustering algorithm for blood vessels segmentation

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Science china(Information Sciences) 2010年第4期53卷 752-759页

作者： HAO JuTao1*, ZHAO JingJing2 & LI MingLu3 1School of Optical-Electrical and Computer engineering, university of Shanghai for Science and Technology, Shanghai 200093, china 2department of Electrical engineering, Shanghai university of Electric Power, Shanghai 200090, china 3department of Computer Science and engineering, Shanghai Jiaotong university, Shanghai 200240, china 1. School of Optical-Electrical and Computer engineering University of Shanghai for Science and Technology Shanghai 200093 China2. Department of Electrical Engineering Shanghai University of Electric Power Shanghai 200090 China3. Department of Computer Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

A three-dimensional representation of vasculature can be extremely important in image-guided neurosurgery, pre-surgical planning. In this paper, a spatial continuity incorporated multi-attribute fuzzy clustering algorithm (MAFCM S) is proposed to segment entire blood vessels from TOF MRA images. This clustering method takes both the intensity information and the geometrical information into account, while most of the cur- rent clustering methods only deal with the former. In this method, a new dissimilarity measure, which integrates the intensity and the geometry shape dissimilarity, is introduced. Because of the presence of the geometrical information, the new measure is able to differentiate the pixels with similar intensity values within different geometrical shape structures. Experimental results show that the new algorithm can get better segmentation.

关键词： fuzzy c-means clustering scale space analysis spatial continuity blood vessel segmentation multi-attribute fuzzy clustering

Design of policy mechanism to promote cleaner production in china

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Journal of Environmental Sciences 2001年第3期13卷 346-350页

作者： ZHANG Tian zhu(department of Environmental Science and engineering, Tsinghua university, Beijing 100084, china. department of Environmental Science and engineering Tsinghua University Beijing 100084 China. zhangtz@***

In order to promote cleaner production in china, a package of policy options was presented based on the identification of the barriers encountered in the CP demonstration project and the effectiveness and feasibility of policy options for the CP implementation were analyzed. Furthermore, the policy mechanism framework was given, which composes of compulsory, economic incentive, social pressure and supportive function. Finally, the implementation strategy of the policy mechanism, in which the emphasis will be changed from compulsory policy options towards economic and social pressure policy options, was proposed.

关键词： cleaner production barrier identification policy mechanism china

An optimal adaptive filtering algorithm with a polynomial prediction model

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Science china(Information Sciences) 2011年第1期54卷 153-162页

作者： TAN JiaJia & ZHANG JianQiu department of Electronic engineering,Fudan university,Shanghai 200433,china 1. department of Electronic engineering Fudan University Shanghai 200433 China

A new approach to the optimal adaptive filtering is proposed in this *** this approach,a polynomial prediction model is used to describe the time-variant/invariant impulse response coeffcients of an identified *** the polynomial prediction model is viewed as the state equations of the identified impulse response coeffcients and the relationships between the inputs and outputs of the system are regarded as the measurements of the states,our adaptive filtering can be achieved in the framework of the Kalman filter. It is understood that Kalman filter is optimal in the sense of the MAP(maximum a posteriori),ML(most likelihood)and MMSE(minimum mean square error)under the linear and Gaussian white noise *** a result,our algorithm is also optimal in the statistical senses as Kalman filter does,provided that the impulse response coeffcients can be modeled by a *** only do the analytical results of the algorithm but also the simulation results show that our algorithm outperforms the traditional known algorithms.

关键词： adaptive filters polynomial prediction model impulse response coeffcients process equation Kalman filter optimal

Analytical solution for wave-induced response of isotropic poro-elastic seabed

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Science china(Technological Sciences) 2010年第10期53卷 2619-2629页

作者： ZHANG YongLi & LI Jie department of Building engineering, Tongji university, Shanghai 200092, china 1. department of Building engineering Tongji University Shanghai 200092 China

By use of separation of variables,the governing equations describing the Biot consolidation model is firstly transformed into a complex coefficient linear homogeneous ordinary differential equation,and the general solution of the horizontal displacement of seabed is constructed by employing a complex wave number,thus,all the explicit analytical solutions of the Biot consolidation model are determined. By comparing with the experimental results and analytical solution of Yamamoto etc. and the analytical solution of Hsu and Jeng,the validity and superiority of the suggested solution are verified. After investigating the influence of seabed depth on the wave-induced response of isotropic poro-elastic seabed based on the present theory,it can be concluded that the influence depth of wave-induced hydrodynamic pressure in the seabed is equal to the wave length.

关键词： linear wave dynamic water pressure seabed analytical solution Biot consolidation model

Operative timing and indications for patients with severe acute pancreatitis: report of 172 cases

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Hepatobiliary & Pancreatic Diseases International 2002年第1期1卷 129-132页

作者： Bei Sun Hong-Chi Jiang Jun Xun From the department of General Surgery, First Clinical Hospital, harbin Medical university harbin 150001, china department of General Surgery First Clinical Hospital Harbin Medical University Harbin 150001 China. sunbei70@***

Objective: To investigate the operative timing and indi-cations for severe acute pancreatitis(SAP).Methods: Data collected from 172 patients with SAPtreated in our hospital since 1980 were analyzed ***: In the 94 patients who had undergone early op-eration before June 1992, 57 (62.8%) healed, 35 (37.2%)died, and 16 (17.0%) had no postoperative compli-cations. In the 78 patients who had been treated after July1992 according to the principle of individualization, 66(84.6%) healed, 12 (15.4%) died, and 37 (47.4%)had no postoperative complications. In the 78 patients32 received non-operative treatment but 30 (93.8%)cured, 12 early operation but 7(58.3%)cured, 18 lateoperation but 13 (72.2%) cured, and 16 selected timeoperation but all ***: It is concluded that individualized thera-py is effective and reasonable for treating SAP. Theindications for early, late and selected time operationshould be emphasized.

关键词： pancreatitis operative therapy operative timing operative indication

Simulation study and function analysis of the dynamic aortic valve

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Progress in Natural Science:Materials International 2006年第5期16卷 512-517页

作者： XIA Dongdong and BAI Jing (department of Biomedical engineering, Tsinghua university, Beijing 100084, china) department of Biomedical engineering Tsinghua University Beijing 100084 China

The dynamic aortic valve (DAV) is a new left ventricular assist device, a micro-axial blood pump implemented at the position of the aortic valve, pumping blood from the left ventricle into the aortic artery. The present dynamic aortic valve operates at 7 different rotation speeds, ranging from 3000 r/min (speed 1) to 9000 r/min (speed 7). Because in vivo experiments need a lot of live animals and take a long period of time, modeling and simulation have been widely used to simulate and analyze hydra-dynamic property of the DAV and its assisting effects. With the measurements from the mock circulatory loop, a mathematic model of the DAV is established and embedded into the previously developed canine circulatory system. Using this model, the effect of the DAV on the failing heart at each rotation speed level is investigated. The vital cardiac variables are computed and compared with in vivo experimental results, which are in good agreement with an acceptable difference mostly 15%. The establishment of the DAV model and its simulation are useful for further improvement of the DAV device.

关键词： dynamic aortic valve mathematic model computer simulation.

Smoothness for the collision local times of bifractional Brownian motions

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Science china Mathematics 2011年第9期54卷 1859-1873页

作者： SHEN GuangJun 1,2,& YAN LiTan 3 1 department of Mathematics,East china university of Science and Technology,Shanghai 200237,china 2 department of Mathematics,Anhui Normal university,Wuhu 241000,china 3.department of Mathematics,Donghua university,Shanghai 201620,china 1. department of Mathematics East China University of Science and Technology Shanghai 200237 China2. Department of Mathematics Anhui Normal University Wuhu 241000 China3. Department of Mathematics Donghua University Shanghai 201620 China

Let B^Hi,Ki ={ Bt^Hi,Ki, t ≥ 0}, i= 1, 2 be two independent bifractional Brownian motions with respective indices Hi ∈ （0, 1） and K∈ E （0, 1]. One of the main motivations of this paper is to investigate f0^Tδ（Bs^H1 ,K1 - the smoothness of the collision local time, introduced by Jiang and Wang in 2009, IT = f0^T δ（Bs^H1,K1）ds, T 〉 0, where 6 denotes the Dirac delta function. By an elementary method, we show that iT is smooth in the sense of the Meyer-Watanabe if and only if min{H-1K1, H2K2} 〈-1/3.

关键词： bifractional Brownian motion collision local time intersection local time chaos expansion

SOME THERMODYNAMIC PROPERTIES OF Pd-In ALLOYS

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Acta Metallurgica Sinica(English Letters) 1997年第4期10卷 311-317页

作者： YL. Chen(department of Materials Science and engineering, Zhejiang university, Hangzhou 310027, china) Zhejiang Univ Hangzhou China

Some thermodynamic parnmeters of Pd-In alloys with 2 to 70 at. H indium have been determined in the temperuture range 800 to 1000℃ from e.m.f measurements ongalvanic cells with an onsen-cotzducting solid electrolyte. Heats of tnising calculated hem the activities are in excellent agreement with calorimetric data. The relative partial excess hee enengy of indiurn assumes unnsually larpe negative values ap to-174kJ/mol for Pd-rich alloys. Two efficts are discussed to account for the non-idealproperties: The rise Of Fermi enerpy as the valence electron8 of indium enter the 4dand 5sP bands of the alloy and the lattice distortion brought about by the differentmolar volumes of the cofnponents. The rise of the Fermi enerpy, as determlned fromthe activity data, indicates a strict adherence of the alloys to the rigid band model.

关键词： galvanic cell activity data Fermi energy,lattice distortion rigid band model