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Risk assessment of fault water inrush during deep mining

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International Journal of Mining Science and Technology 2022年第2期32卷 423-434页

作者： Zhaodan cao Qixiong Gu zhen Huang Jiaju fu College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China ZJU-UIUC Institute Zhejiang UniversityHaining 314400China School of Resources and Environment Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Guiyang Architectural Design and Surveying Prospecting CO.LTD Guiyang 550082China

With the gradual depletion of shallow coal resources,the Yanzhou mine in China will enter the lower coal seam mining ***,as mining depth increases,lower coal seam mining in Yanzhou is threatened by water inrush in the Benxi Formation limestone and Ordovician *** existing prediction models for the water burst at the bottom of the coal seam are less accurate than expected owing to various controlling factors and their intrinsic *** analyzing the hydrogeological exploration data of the Baodian lower seam and combining the results of the water inrush coefficient method and the Yanzhou mine pressure seepage test,an evaluation model of the seepage barrier capacity of the fault was *** evaluation results show the water of the underlying limestone aquifer in the Baodian mine area mainly threatens the lower coal mining through the fault fracture *** security of mining above confined aquifer in the Baodian mine area gradually decreases from southwest to *** comparing the water inrush coefficient method and the evaluation model of fault impermeability,the results show the evaluation model based on seepage barrier conditions is closer to the actual situation when analyzing the water breakout situation at the working face.

关键词： Lower coal seam Mining above confined aquifer Water inrush coefficient Water injection test Impermeability strength Water-inrush in fault

Generation of chimeric monkeys using embryonic stem cells

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Zoological Research 2023年第6期44卷 1154-1155页

作者： Jing cao zhen Liu Institute of Neuroscience CAS Center for Excellence in Brain Science and Intelligence TechnologyCAS Key Laboratory of Primate NeurobiologyState Key Laboratory of NeuroscienceChinese Academy of SciencesShanghai 200031China

Embryonic stem cells(ESCs)represent a subtype of pluripotent stem cells(PSCs)derived from the inner cell mass of *** cells exhibit three principal features:the capacity for unlimited self-replication,the ability to differentiate into diverse somatic cell types in vitro,and the potential to contribute to chimera animals in vivo upon reintroduction into the host ***,ESCs are widely used in basic and biomedical research,as well as in applications such as cell replacement therapy and the creation of genetically modified animal models.

关键词： stem creation diverse

Interfacial Structures Governed Plastic Deformation Behaviors in Metallic Multilayers

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Acta Metallurgica Sinica(English Letters) 2016年第2期29卷 199-204页

作者： Ming-zhen Wei zhen-Hua cao Xiang-Kang Meng Institute of Materials Engineering National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences Nanjing University Department of Physics School of Science Linyi University

In this work, we have investigated the mechanical properties of Cu/Ta, Ag/Cu and Ag/Nb multilayers with different heterogeneous interfaces. The results suggest that when individual layer thickness （h） is larger than 5-10 nm, the hardness/strength of three different multilayer systems has the similar length scale effect with decreasing layer thickness, while when h ≤ 5 nm, the three multilayer systems show remarkably different plastic deformation behaviors. The strength curves exhibit the variation trends of unchanging, softening and increasing corresponding to Cu/Ta, Ag/Cu and Ag/Nb multilayers, respectively. The microstructure analysis shows that three kinds of multilayers have totally different interfacial structures, which lead to the different strengthening or softening mechanisms.

关键词： Metallic multilayers Plastic deformation Interfacial structures Strengthening mechanism

The rate of convergence on fractional power dissipative operator on some sobolev type spaces

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Applied Mathematics(A Journal of Chinese Universities) 2021年第3期36卷 412-419页

作者： cao zhen-bin WANG Meng Department of Mathematics Zhejiang UniversityHangzhou 310027China

In[3],Chen,Deng,Ding and Fan proved that the fractional power dissipative operator is bounded on Lebesgue spaces Lp(Rn),Hardy spaces Hp(Rn)and general mixed norm spaces,which implies almost everywhere convergence of such *** this paper,we study the rate of convergence on fractional power dissipative operator on some sobolev type spaces.

关键词： convergence speed dissipative operator sobolev type spaces

Preparation mechanism,physical characteristic and antitumor activity of nano-scheelite

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 468-474页

作者： Lin cao fu-qiang Yang Jie-xin cao School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Peking University Health Science Center Beijing 100083 China

After preparing the EU^3＋-doped scheelite nano-material by Pechini method with the nanoparticles of 30-50 nm in diameter, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM） were used to show a microcosmic description of the particle morphology and crystal structure. The spectrum signature of the nano-scheelite, which was taken by fluorescence spectrometer, was used to discuss the difference of luminescent performance between the nano-scheelite and bulk scheelite. The atomic site of the nano-scheelite was intuitively shown through HRTEM images and HRTEM simulated images from the relation between luminescent properties and crystal structure, which was analyzed by spectrum probe. The results of antitumor activity examined by the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） method show that the inhibition of human promyelocytic leukemia cell line （HL60） is enhanced immediately with increasing the concentration and presents a reliance on the quantity. The results of fluorescence spectra and structure show that the antitumor activity has something to do with micro-structure and surface charge.

关键词： scheelite fluorescence spectrum atomic site anti-tumor activity

Fredholm Composition Operators on Riemann Surfaces

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Acta Mathematica Sinica,English Series 2005年第4期21卷 869-872页

作者： Guang fu cao Department of Mathematics Guangzhou University Guangzhou 510405 P. R. China

It is proved that the invertibility of a composition operator on the differential form space for a Riemann surface is equivalent to its Fredholmness. In addition, the Fredholmness of weighted composition operators is ... 详细信息

关键词： Riemann surface Composition operator Fredholm operator

Vision-based Stabilization of Nonholonomic Mobile Robots by Integrating Sliding-mode Control and Adaptive Approach

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 21-28页

作者： cao zhengcai YIN Longjie fu Yili College of Information Science and Technology Beijing University of Chemical Technology The State Key Laboratory of Robotics and Systems Harbin Institute of Technology

Vision-based pose stabilization of nonholonomic mobile robots has received extensive attention. At present, most of the solutions of the problem do not take the robot dynamics into account in the controller design, so that these controllers are difficult to realize satisfactory control in practical application. Besides, many of the approaches suffer from the initial speed and torque jump which are not practical in the real world. Considering the kinematics and dynamics, a two-stage visual controller for solving the stabilization problem of a mobile robot is presented, applying the integration of adaptive control, sliding-mode control, and neural dynamics. In the first stage, an adaptive kinematic stabilization controller utilized to generate the command of velocity is developed based on Lyapunov theory. In the second stage, adopting the sliding-mode control approach, a dynamic controller with a variable speed function used to reduce the chattering is designed, which is utilized to generate the command of torque to make the actual velocity of the mobile robot asymptotically reach the desired velocity. furthermore, to handle the speed and torque jump problems, the neural dynamics model is integrated into the above mentioned controllers. The stability of the proposed control system is analyzed by using Lyapunov theory. Finally, the simulation of the control law is implemented in perturbed case, and the results show that the control scheme can solve the stabilization problem effectively. The proposed control law can solve the speed and torque jump problems, overcome external disturbances, and provide a new solution for the vision-based stabilization of the mobile robot.

关键词： nonholonomic mobile robots vision-based stabilization sliding-mode control adaptive control neural dynamics

A new thermosensor from rice

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Molecular Plant 2022年第7期15卷 1090-1091页

作者： zhen Wang Xiaofeng cao State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Global warming is increasing the frequency of extreme-temperature occurrence ***,owing to their sessile nature,are inevitably exposed to temperature fluctuations during their *** the face of climate chariges,heat stress is *** a challenge for agriculture,which poses a severe threat to crop harvests(Gong et al.,2020).For example,even 1℃ increased temperature would severely decrease the global yield of many crops(Zhao et al.,2017).

关键词： crops decrease extreme

Multiple model predictive control of perching maneuver based on guardian maps

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Chinese Journal of Aeronautics 2022年第5期35卷 347-360页

作者： Rui cao Huiwen WAN zhen HE Yuping LU College of Automated Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Considering the strong nonlinearity of Unmanned Aerial Vehicles(UAVs)resulting from high Angle of Attack(AOA)and fast maneuvering,we present a multi-model predictive control strategy for UAV maneuvering,which has a small amount of online ***,we divide the maneuver envelope of UAV into several sub-regions on the basis of the gap metric theory.A novel algorithm is then developed to determine the ploytopic model for each *** to this,a Robust Model Predictive Control based on the Idea of Comprehensive optimization(ICE-RMPC)is *** control law is designed offline and optimized online to reduce the computational ***,the ICE-RMPC method is applied to design the controllers of *** addition,to guarantee the stability of whole closed-loop system,a multi-model switching control strategy based on guardian maps is put ***,the tracking performance of proposed control strategy is demonstrated by an illustrative example.

关键词： Guardian maps Model predictive control Multi-Model switching rule Online comprehensive design Perching maneuver