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Nuclear Science and Techniques 1998年第3期9卷 153-156页

作者： ZhangPei－qun WangWen－qi 等 InstituteofHighEnergyPhysics theChineseAcademyofSciencesBeijing100080 InstituteofOceanology theChine

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｉｓｔｒｉｃｔｏｆｔｈｅＪｉａｏｚｈｏｕＢａｙｉｎｔｈｅｅａｓｔｅｒｎＣｈｉｎａｉｓａｎｅｘａｍｐｌｅｏｆｈｉｇｈｌｙａｎｔｈｒｏｐｏｇｅｎｉｃｒｅｓｕｌｔｅｄｃｏｍｐｌｅｘｅｃｏ... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｉｓｔｒｉｃｔｏｆｔｈｅＪｉａｏｚｈｏｕＢａｙｉｎｔｈｅｅａｓｔｅｒｎＣｈｉｎａｉｓａｎｅｘａｍｐｌｅｏｆｈｉｇｈｌｙａｎｔｈｒｏｐｏｇｅｎｉｃｒｅｓｕｌｔｅｄｃｏｍｐｌｅｘｅｃｏｓｙｓｔｅｍｗｈｉｃｈｍｅｒｇｅｓ...

关键词：环境评估生物监视器中子活化分析原子吸收光谱法

Study on Dynamic Characteristics of Hydraulic Pumping Unit on Offshore Platform

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China Ocean Engineering 2017年第6期31卷 693-699页

作者： CHANG Zong-yu YU Yan-qun qi Yao-guang College of Engineering Ocean University of ChinaQingdao 266100China College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China

A new technology of offshore oil rod pumping production is developed for offshore heavy oil recovery. A new type of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure is designed based on the spatial characteristics of offshore platforms. By combining the strengths of sinusoidal velocity curve and trapezoidal velocity curve, a kinematical model of the acceleration, the velocity and displacement of the pumping unit＇s hanging point is established. The results show that the pumping unit has good kinematic characteristics of smooth motion and small dynamic load. The multi-degree-of-freedom dynamic model of the single-well pumping unit is established. The first and second order natural frequencies of the sucker rod string subsystem and the pumping unit subsystem are studied. The results show that the first and the second order natural frequencies among the pumping rod string, pumping unit-platform subsystem and the dynamic excitation have differences over 5 times from each other, indicating that resonance phenomenon will not appear during the operation and the dynamic requirements for field use are met in the system.

关键词： offshore platform platform pumping unit kinematic model dynamic model multiple degrees of freedom

Classification analysis of microarray data based on ontological engineering

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 638-643页

作者： LI Guo-qi SHENG Huan-ye Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

Background knowledge is important for data mining, especially in complicated situation. Ontological engineering is the successor of knowledge engineering. The sharable knowledge bases built on ontology can be used to provide background knowledge to direct the process of data mining. This paper gives a common introduction to the method and presents a practical analysis example using SVM (support vector machine) as the classifier. Gene Ontology and the accompanying annotations compose a big knowledge base, on which many researches have been carried out. Microarray dataset is the output of DNA chip. With the help of Gene Ontology we present a more elaborate analysis on microarray data than former researchers. The method can also be used in other fields with similar scenario.

关键词： Ontological engineering Data mining Microarray Support vector machine (SVM)

Dynamic phase transition theory

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Science China(Physics,Mechanics & Astronomy) 2023年第2期66卷 102-108页

作者： qi-Jun ye Xin-Zheng Li State Key Laboratory for Artificial Microstructure and Mesoscopic Physics Frontier Science Center for Nano-optoelectronics and School of PhysicsPeking UniversityBeijing 100871China Interdisciplinary Institute of Light-Element Quantum Materials Research Center for Light-Element Advanced Materialsand Collaborative Innovation Center of Quantum MatterPeking UniversityBeijing 100871China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China

Thermodynamic conventions suffer from describing dynamical distinctions,especially when the structural and energetic changes induced by rare events are *** using the ensemble theory in the trajectory space,we present a statistical approach to address this *** than spatial particle-particle interaction which dominates thermodynamics,the temporal correlation of events dominates the *** zeros of dynamic partition function mark phase transitions in the space-time,i.e.,dynamic phase transition(DPT),as Yang and Lee formulate traditional phase transitions,and hence determine dynamic phases on both sides of the *** to the role of temperature(pressure) as thermal(mechanical) potential,we interpret the controlling variable of DPT,i.e., dynamic field,as the dynamical *** findings offer possibility towards a unified picture of phase and phase transition.

关键词： transition phase transition

Bifurcation control of solid angle car-following model through a time-delay feedback method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第9期24卷 828-840页

作者： qun JI Hao LYU Hang YANG qi WEI Rongjun CHENG Faculty of Maritime and Transportation Ningbo UniversityNingbo 315211China Ningbo University of Finance&Economics Ningbo 315175China

In order to alleviate unstable factor-caused bifurcation and reduce oscillations in traffic flow,a feedback control with consideration of time delay is designed for the solid angle model(SAM).The stability and bifurcation condition of the new SAM is derived through linear analysis and bifurcation analysis,and then accurate range of stable region is *** order to explore the mechanism of the influence of multiple parameter combinations on the stability of controlled systems,a definite integral stabilization method is provided to determine the stable interval of time delay and feedback *** simulations are explored to verify the feasibility and effectiveness of the proposed model,which also demonstrate that feedback gain and delay are two key factors to alleviate traffic congestion in the SAM.

关键词： Solid angle model(SAM) Time-delay Hopf bifurcation Feedback control Parameter calibration

Regulation of intestinal stem cell fate specification

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Science China(Life Sciences) 2015年第6期58卷 570-578页

作者： qi Zhen CHEN ye-Guang State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua-Peking Center for Life Sciences School of Life SciencesTsinghua University

The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.

关键词： intestinal stem cells Wnt BMP Notch EGF fate specification

The consensus on liver autotransplantation from an international panel of experts

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Hepatobiliary & Pancreatic Diseases International 2017年第1期16卷 10-16页

作者： qi-Fa ye Norbert Senninger Zhongnan Hospital of Wuhan University Institute of Hepatobiliary Diseases of Wuhan University Transplant Center of Wuhan University Hubei Key Laboratory of Medical Technology on Transplantation Research Center of National Health Ministry on Transplantation Medicine Engineering and Technology The 3rd Xiangya Hospital of Central South University Department of General Surgery University Clinics of Münster

IntroductionMore than 1.0 million patients worldwide are diagnosed with space-occupying lesions in the liver every year, with the number approaching 0.5 million per year in China, and only 20% of the lesions are resectable Due to a lack of available donors, only a limited number of patients underwent allogeneic liver transplantation, the remaining patients simply receive palliative care. Therefore, discovering new options for treating these patients is a high priority. Liver autotransplantation （LAT） is a surgical technique that adopts liver transplantation skills to radically treat spaceoccupying hepatic lesions, benign or malignant,

关键词： The consensus on liver autotransplantation from an international panel of experts

Stability and Nonlinear Response Analysis of Parametric Vibration for Elastically Constrained Pipes Conveying Pulsating Fluid

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Acta Mechanica Solida Sinica 2023年第2期36卷 230-240页

作者： Meng-Yuan Hao Hu Ding Xiao-ye Mao Li-qun Chen Shanghai Key Laboratory of Mechanics in Energy Engineering School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

Usually,the stability analysis of pipes with pulsating flow velocities is for rigidly constrained pipes or cantilevered *** this paper,the effects of elastic constraints on pipe stability and nonlinear responses under pulsating velocities are investigated.A mechanical model of a fluid-conveying pipe under the constraints of elastic clamps is established.A partial differentialintegral nonlinear equation governing the lateral vibration of the pipe is *** natural frequencies and mode functions of the pipe are ***,the stable boundary and nonlinear steady-state responses of the parametric vibration for the pipe are established ***,the analytical solutions are verified *** results of this work reveal some interesting *** is found that the elastic constraint stiffness in the direction perpendicular to the axis of the pipe does not affect the critical flow velocity of the ***,the constraint stiffness has a significant effect on the instability boundary of the pipe with pulsating flow ***,an increase in the stiffness of the constraint increases the instable region of the pipe under parametric ***,when the constraint stiffness is increased,the steady-state response amplitude of the nonlinear vibration for the pipe is significantly ***,the effects of the constraint stiffness on the instable region and vibration responses of the fluid-conveying pipe are different when the flow velocity is pulsating.

关键词： Pipe conveying fluid Elastic boundary Stability Nonlinear dynamics Parametric vibration Multi-scale method

Effect of Spine Motion on Mobility in Quadruped Running

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Chinese Journal of Mechanical Engineering 2014年第6期27卷 1150-1156页

作者： CHEN Dongliang LIU qi DONG Litao WANG Hong ZHANG qun College of Mechanical and Electrical Engineering Harbin Engineering University

Most of current running quadruped robots have similar construction： a stiff body and four compliant legs. Many researches have indicated that the stiff body without spine motion is a main factor in limitation of robots’ mobility. Therefore, investigating spine motion is very important to build robots with better mobility. A planar quadruped robot is designed based on cheetahs’ morphology. There is a spinal driving joint in the body of the robot. When the spinal driving joint acts, the robot has spine motion; otherwise, the robot has not spine motion. Six group prototype experiments with the robot are carried out to study the effect of spine motion on mobility. In each group, there are two comparative experiments： the spinal driving joint acts in one experiment but does not in the other experiment. The results of the prototype experiments indicate that the average speeds of the robot with spine motion are 8.7%–15.9% larger than those of the robot without spine motion. Furthermore, a simplified sagittal plane model of quadruped mammals is introduced. The simplified model also has a spinal driving joint. Using a similar process as the prototype experiments, six group simulation experiments with the simplified model are conducted. The results of the simulation experiments show that the maximum rear leg horizontal thrusts of the simplified mode with spine motion are 68.2%–71.3% larger than those of the simplified mode without spine motion. Hence, it is found that spine motion can increase the average running speed and the intrinsic reason of speed increase is the improvement of the maximum rear leg horizontal thrust.

关键词： quadruped robot spinal driving joint spine motion mobility locomotion experiment

Buckling optimization of curvilinear fiber-reinforced composite structures using a parametric level set method

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Frontiers of Mechanical Engineering 2024年第1期19卷 149-160页

作者： ye TIAN Tielin SHI qi XIA State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Owing to their excellent performance and large design space,curvilinear fiber-reinforced composite structures have gained considerable attention in engineering fields such as aerospace and *** addition to the stiffness and strength of such structures,their stability also needs to be taken into account in the *** study proposes a level-set-based optimization framework for maximizing the buckling load of curvilinear fiber-reinforced composite *** the proposed method,the contours of the level set function are used to represent fiber *** a composite laminate with a certain number of layers,one level set function is defined by radial basis functions and expansion coefficients for each ***,the fiber angle at an arbitrary point is the tangent orientation of the contour through this *** the finite element of buckling,the stiffness and geometry matrices of an element are related to the fiber angle at the element *** study considers the parallelism constraint for fiber *** the sensitivity calculation of the objective and constraint functions,the method of moving asymptotes is utilized to iteratively update all the expansion coefficients regarded as design *** numerical examples under different boundary conditions are given to validate the proposed *** show that the optimized curved fiber paths tend to be parallel and equidistant regardless of whether the composite laminates contain holes or ***,the buckling resistance of the final design is significantly improved.

关键词： buckling optimization curvilinear fiber composite structure level set method manufacturing constraint