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Experimental study of hydraulic fracture propagation with multi-cluster in-plane perforations in a horizontal well

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Petroleum Science 2024年第5期21卷 3258-3270页

作者： Xian shi Yuan-Yuan Yang Xiang-Wei Kong qi gao Shu Jiang Hai-Jun Mao College of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China State Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongPR China School of Petroleum Engineering Yangtze UniversityWuhan430100HubeiPR China Key Laboratory of Drilling and Production Engineering for Oil and Gas Wuhan430100HubeiPR China School of Engineering The University of Western AustraliaPerthWA6009Australia Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education School of Earth ResourcesChina University of GeosciencesWuhan430074HubeiPR China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071HubeiPR China

Tri-axial fracturing studies were carried out to understand the impact of lateral mechanical parameters on fracture propagation from multiple in-plane perforations in horizontal wells. Additionally, the discussion covered the effects of geology, treatment, and perforation characteristics on the non-planar propagation behavior. According to experimental findings, two parallel transverse fractures can be successfully initiated from in-plane perforation clusters in the horizontal well because of the in-plane perforation, the guide nonuniform fishbone structure fracture propagation still can be exhibited. The emergence of transverse fractures and axial fractures combined as complex fractures under low horizontal principal stress difference and large pump rate conditions. The injection pressure was also investigated, and the largest breakdown pressure can be also found for samples under these *** increase in perforation number or decrease in the cluster spacing could provide more chances to increase the complexity of the target stimulated zone, thus affecting the pressure fluctuation. In a contrast, the increase in fracturing fluid viscosity can reduce the multiple fracture complexity. The fracture propagation is significantly affected by the change in the rock mechanical properties. The fracture geometry in the high brittle zone seems to be complicated and tends to induce fracture reorientation from the weak-brittle zone. The stress shadow effect can be used to explain the fracture attraction, branch, connection, and repulsion in the multiple perforation clusters for the horizontal *** increase in the rock heterogeneity can enhance the stress shadow effect, resulting in more complex fracture geometry. In addition, the variable density perforation and temporary plugging fracturing were also conducted, demonstrating higher likelihood for non-uniform multiple fracture propagation. Thus, to increase the perforation efficiency along the horizontal well, it is

关键词： Heterogeneous rock In-plane perforation Stress shadowing Tri-axial fracturing Multiple perforation clusters

Suppressed formation of CO_2 and H_2O in the oxidative coupling of methane over La_2O_3/MgO catalyst by surface modification

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Journal of Natural Gas Chemistry 2010年第2期19卷 173-178页

作者： Zhiming gao Yingxiao shi Department of Chemistry School of Science Beijing Institute of Technology Beijing 100081 China

Oxidative coupling of methane （OCM） is a promising way to convert methane into C2 ***,CO2 and H2O are by-products of the *** utilize the higher activity of lanthanum oxide and save its usage,MgO supported La2O3 catalyst was *** modification of the catalyst with nitric acid was made to suppress the formation of the *** results indicated that the addition of nitric acid increased the surface oxygen species with binding energy of ca.531.7 eV and at the same time reduced the pore volume of the *** effects of nitric acid finally led to the increase of C2 selectivity and the decrease of the by-products *** selectivity was found about 14%-18% over the catalysts adopted in this work.

关键词： methane oxidative coupling catalyst design XPS magnesium oxide

Structure and receptor-binding properties of an airborne transmissible avian infl uenza A virus hemagglutinin H5(VN1203mut)

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Protein & Cell 2013年第7期4卷 502-511页

作者： Xishan Lu Yi shi Wei Zhang Yanfang Zhang Jianxun qi George F gao College of Veterinary Medicine China Agricultural UniversityBeijing 100193China Research Network of Immunity and Health(RNIH) Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing 100101China CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Laboratory of Protein Engineering and Vaccines Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention(China CDC)Beijing 102206China

Avian infl uenza A virus continues to pose a global threat with occasional H5N1 human infections,which is em-phasized by a recent severe human infection caused by avian-origin H7N9 in *** these viruses do not transmit effi ciently in human *** a few ami-no acid substitutions of the hemagglutinin H5 protein in the laboratory,two H5 mutants have been shown to obtain an air-borne transmission in a mammalian ferret *** in this study one of the mutant H5 proteins devel-oped by Kawaoka’s group(VN1203mut)was expressed in a baculovirus system and its receptor-binding properties were *** herein show that the VN1203mut had a dramatically reduced binding affi nity for the avianα2,3-linkage receptor compared to wild type but showed no detectable increase in affi nity for the humanα2,6-linkage receptor,using Surface Plasmon Resonance ***,the crystal structures of the VN1203mut and its complexes with either human or avian receptors demon-strate that the VN1203mut binds the human receptor in the same binding manner(cis conformation)as seen for the HAs of previously reported 1957 and 1968 pandemic influenza *** receptor binding and crystallo-graphic data shown here further confi rm that the ability to bind the avian receptor has to decrease for a higher hu-man receptor binding affi *** the Q226L substitution is shown important for obtaining human receptor binding,we suspect that the newly emerged H7N9 binds human receptor as H7 has a Q226L substitution.

关键词： airborne transmission H5 avian infl uenza structure receptor binding

Characterization and tribological investigation of self-assembled trimethoxysilyl-functionalized poly(phthalazinone ether ketone)thin films on glass substrates

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Chinese Chemical Letters 2010年第8期21卷 973-975页

作者： qi Feng Jin Gong Xiong Liao shi Jun Yu Xi gao Jian State Key Laboratory. of Fine Chemicals Dalian University of Technology Dalian 116012 Liaoning China College of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 China Liaoning High Performance Resin Engineering Research Center Dalian 116012 China Department of Polymer Science and Materials Dalian University of Technology Dalian 116012 China

Trimethoxysilyl-functionalized PPEK（PKGS） films had been designed to serve as wear resistant coatings for silicon surfaces. These surface films were formed by a dip-coating technique applied to self-assembled monolayers（SAMs）.The formation and wetting behavior of PKGS films were characterized by means of contact angle *** friction coefficient of the film prepared is very low（about 0.1）,and the anti-wear behavior is good,with a lack of failure after sliding over 1800 s.

关键词： Phthalazinone Poly(aryl ether ketone) Self-assemble film Friction and wear

Coupled effects of climate change and human activities on vegetation dynamics in the Southwestern Alpine Canyon Region of China

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Journal of Mountain Science 2024年第10期21卷 3234-3248页

作者： LAI Jinlin qi shi School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China

The driving effects of climate change and human activities on vegetation change have always been a focal point of ***,the coupling mechanisms of these driving factors across different temporal and spatial scales remain *** Southwestern Alpine Canyon Region of China(SACR),as an ecologically fragile area,is highly sensitive to the impacts of climate change and human *** study constructed a vegetation cover dataset for the SACR based on the Enhanced Vegetation Index(EVI)from 2000 to *** autocorrelation,Theil-Sen trend,and Mann-Kendall tests were used to analyze the spatiotemporal characteristics of vegetation cover *** main drivers of spatial heterogeneity in vegetation cover were identified using the optimal parameter geographic detector,and an improved residual analysis model was employed to quantify the relative contributions of climate change and human activities to interannual vegetation cover *** main findings are as follows:Spatially,vegetation cover exceeds 60%in most areas,especially in the southern part of the study ***,the border area between Linzhi and Changdu exhibits lower vegetation *** factors are the primary drivers of spatial heterogeneity in vegetation cover,with temperature having the most significant influence,as indicated by its q-value,which far exceeds that of other ***,the interaction q-value between the two factors significantly increases,showing a relationship of bivariate enhancement and nonlinear *** terms of temporal changes,vegetation cover shows an overall improving trend from 2000 to 2020,with significant increases observed in 68.93%of the study *** these,human activities are the main factors driving vegetation cover change,with a relative contribution rate of 41.31%,while climate change and residual factors contribute 35.66%and 23.53%,*** thoroughly exploring the coupled mechanisms of vegetation change,this

关键词： Enhanced vegetation index Climate change Human activities Spatial heterogeneity Coupled mechanisms

Network selection based on multiple attribute decision making and group decision making for heterogeneous wireless networks

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 92-98,114页

作者： shi Zheng ZHU qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

One of the key issues for radio resources management is network selection strategy in heterogeneous scenarios. In order to provide ubiquitous service, the paper puts forward a network selection algorithm based on multiple attribute decision making （MADM） and group decision making （GDM）. Firstly, the proposed algorithm acquires attribute weights＇ vectors of the subjective and objective decision makers based on MADM, and then the two attribute weights＇ vectors are synthesized to be a new attribute weights＇ vector by using GDM. Considering that the results of GDM should be reasonable and convincible, the criterion of consistency is adopted for judging the compatibility of group judgments. More specit]cally, the algorithm takes into account not only objective attributes of networks but also the preference of subscribers and traft]c class Hence it guarantees that the subscribers can not select the networks with poor performance depending on their preference. The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide subscribers with satisfactory quality of service （QoS）.

关键词： heterogeneous wireless networks group decision making compatibility criterion analytic hierarchy process entropy method

Vibration Suppression for Active Magnetic Bearings Using Adaptive Filter with Iterative Search Algorithm

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 61-71页

作者： Jin-Hui Ye Dan shi Yue-Sheng qi Jin-Hui gao Jian-Xin Shen IEEE Department of Electrical Engineering Zhejiang UniversityHangzhou 310027China CES and IEEE

Active Magnetic Bearing(AMB) is a kind of electromagnetic support that makes the rotor movement frictionless and can suppress rotor vibration by controlling the magnetic force. The most common approach to restrain the rotor vibration in AMBs is to adopt a notch filter or adaptive filter in the AMB controller. However, these methods cannot obtain the precise amplitude and phase of the compensation current. Thus, they are not so effective in terms of suppressing the vibrations of the fundamental and other harmonic orders over the whole speed range. To improve the vibration suppression performance of AMBs,an adaptive filter based on Least Mean Square(LMS) is applied to extract the vibration signals from the rotor displacement signal. An Iterative Search Algorithm(ISA) is proposed in this paper to obtain the corresponding relationship between the compensation current and vibration signals. The ISA is responsible for searching the compensating amplitude and shifting phase online for the LMS filter, enabling the AMB controller to generate the corresponding compensation force for vibration suppression. The results of ISA are recorded to suppress vibration using the Look-Up Table(LUT) in variable speed range. Comprehensive simulations and experimental validations are carried out in fixed and variable speed range, and the results demonstrate that by employing the ISA, vibrations of the fundamental and other harmonic orders are suppressed effectively.

关键词： Active Magnetic Bearing(AMB) Adaptive filter Iterative search algorithm Least mean square(LMS) Vibration suppression

Numerical simulation of viscous flows with adaptively refined Cartesian grid

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航空动力学报 2014年第2期29卷 467-474页

作者： HAN Yu-qi gao Ge National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Energy and Power EngineeringBeijing University of Aeronautics and Astronautics

Quadtree-based Cartesian grid was automatically generated from specified *** refinements were performed according to geometric parameters and solution of flow *** altered CCST(curvature corrected symmetry technique)approach was proposed to apply solid wall boundary conditions. Driven flows in a square cavity and flows around NACA0012airfoil were simulated and compared with the result of published structured grid and stretched Cartesian *** results show that solid wall boundary condition are accurately applied by current altered CCST approach,while incompressible/compressible subsonic, transonic and supersonic viscous flows are adequately simulated with adaptively refined Cartesian grid.

关键词： adaptively refined Cartesian grid viscous flow CCST(curvature corrected symmetry technique) boundary condition

Approaches and Perspectives of the Westward Spread of Traditional Chinese Medicine: A Case Study of the Radicis Chynae

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Chinese Medicine and Culture 2021年第3期4卷 141-147页

作者： Xi gao Department of History Fudan UniversityShanghai 200433China

Some Western scholars have re-examined the concept of“Chinese medicine”and its knowledge system under the influence of global history research methods in recent years,in an attempt to understand the factors that led to the spread of Chinese medicine around the world,and what kind of Chinese medicine is constituted outside of ***,researchers have studied the initial stage of traditional Chinese medicine(TCM)’s entry into the western world,tracing its roots and observing new knowledge systems formed in the process of cross-cultural *** to the research of Western scholars,this paper studies the Radicis Chynae(《中国根书简》Letters on Chinese Root),a monograph written by Andreas Vesalius,a famous European anatomist who lived in the 16th *** author of this article examined the understanding and interpretation of Chinese medicine by the European intelligentsia from 16th to 19th century,investigated the influence of the westward spread of TCM on the scientific revolution and medical progress in Europe,and analyzed its relationship with the rise of Sinology in *** article discusses the knowledge interaction between Chinese medicine and the formation of modern European medicine from the perspective of global history and cross-culture.

关键词： Andreas Vesalius Charles V China root Tu Fu Ling(土茯苓Rhizoma Smilacis Glabrae) westward spread of traditional Chinese medicine