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Influence of volute distortion on the performance of turbocharger centrifugal compressor with vane diffuser

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Science China(Technological Sciences) 2013年第11期56卷 2778-2786页

作者： ZHEng XinQian JIN lei TAMAKI Hideaki State Key Laboratory of Automotive Safety and Energy Tsinghua University Turbo Machinery and Engine Technology Department IHI Corporation

As the geometry of the volute of turbocharger compressor is non-axisymmetric,it causes a distortion at the outlet of the diffuser and influences the upstream components.A distortion model in which a pressure distortion was applied as outlet boundary condition was established to simulate the distortion induced by the *** turned out to be sufficient to impose a circumferentially asymmetric pressure distribution at the outlet of the diffuser to replace the *** on the distortion model which was verified,the influence of the amplitude of the distortion on the performance of centrifugal compressor was studied in *** results show that the distortion severely harms aerodynamic stability of the investigated *** larger the amplitude of the distortion,the worse the performance of the *** distortion induced by asymmetric volute propagates to upstream components and causes local flow separation at part of diffuser and impeller,and then causes the compressor *** the amplitude of the volute distortion is 10%,the stable flow range of the centrifugal compressor decreases to near *** authors’knowledge,the relationship between the compressor performance and distortion amplitude is first obtained quantitatively,which provides evidence to improve the performance of turbocharger compressor by decreasing the distortion induced by asymmetric volute.

关键词： turbocharger vane diffuser centrifugal compressor stability distortion

High-entropy ceramics:Present status,challenges,and a look forward

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Journal of Advanced Ceramics 2021年第3期10卷 385-441页

作者： Huimin XIAng yan XIng Fu-zhi DAI Hongjie WAng lei SU lei MIAO Guojun ZHAng yiguang WAng Xiwei QI lei yAO Hailong WAng Biao ZHAO Jianqiang LI yanchun ZHOU Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China New Energy Technology Engineering Laboratory of Jiangsu Province Nanjing University of Posts and TelecommunicationsNanjing 210023China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Guangxi Key Laboratory of Information Materials Guangxi Collaborative Innovation Center of Structure and Property for New Energy and MaterialSchool of Material Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China Institute of Functional Material College of Material Science and EngineeringDonghua UniversityShanghai 201620China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210China College of Material Science and Engineering Shenzhen UniversityShenzhen 518060China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology CAS Key Laboratory of Green Process and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal *** in the infant stage,the emerging of this new family of materials has brought new opportunities for material design and property *** from metals,the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon *** from strengthening,hardening,and low thermal conductivity that have already been found in high-entropy alloys,new properties like colossal dielectric constant,super ionic conductivity,severe anisotropic thermal expansion coefficient,strong electromagnetic wave absorption,etc.,have been discovered in *** a response to the rapid development in this nascent field,this article gives a comprehensive review on the structure features,theoretical methods for stability and property prediction,processing routes,novel properties,and prospective applications of *** challenges on processing,characterization,and property predictions are also ***,future directions for new material exploration,novel processing,fundamental understanding,in-depth characterization,and database assessments are given.

关键词： high-entropy ceramics(HECs) processing structure properties applications

Empilrical Likelihood for Non-parametric Regression Models with Missing Responses:Multiple Design Case

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Acta Mathematicae Applicatae Sinica 2011年第1期27卷 1-12页

作者： Qing-zhu lei y.ng-song Qin School of Mathematical Sciences Guangxi Normal University Guilin Guangxi 541004 China

Empirical likelihood （EL） ratio statistic on θ=g（x） is constructed based on the inverse probability weighted imputation approach in a nonparametric regression model y = g（x）＋ε （x ∈ [0, 1]p） with fixed designs and missing responses, which asymptotically has X1^2 distribution. This result is used to obtain a EL based confidence interval on θ.

关键词： Nonparametric regression empirical likelihood missing at random confidence interval

A potentiometric cobalt-based phosphate sensor based on screen-printing technology

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Frontiers of Environmental Science & Engineering 2014年第6期8卷 945-951页

作者： lei ZHU Xiaohong ZHOU Hanchang SHI School of Environment Tsinghua University Beijing 100084 China Division of Ecology and Environment Yangtze Delta Region Institute of Tsinghua University Jiaxing 314006 China

A potentiometric cobalt-based screen-pritning sensor was fabricated by electroplating cobalt on the surface of a screen-printing electrode as the sensitive layer for the determination of dihydrogenphosphate （H2PO4） in wastewater samples. The electrochemical performance of this sensor was fully examined to determine its detection calibration, detection limit, response time, selectivity, and interference with pH, various ions, and dissolved oxygen （DO）. The cobalt-based phosphate sensor showed a phosphate-selective potential response in the range of 10 5mol·L^-1 to 10^-1 mol^-1, yielding a detection limit of 3.16 × 10μmol·L^l and a slope of -37.51 mV·decade＇ in an acidic solution （pH 4.0） of H2PO4-. DO and pH were found to interfere with sensor responses to phosphate. Ultimately, the performance of the sensor was validated for detecting wastewater samples from the Xiaojiahe Waste- water Treatment Plant against the standard speetrophotometric methods for HzPO4 analysis. The discrepancy between the two methods was generally ＋5% （relative standard deviation）. Aside from its high selectivity, sensitivity, and stability, which are comparable with conventional bulk Co-wire sensors, the proposed phosphate sensor presents many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices, such as flow injectors.

关键词： phosphate cobalt screen-printing technology electroplate wastewater

A dynamic bidirectional heuristic trust path search algorithm

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CAAI Transactions on Intelligence Technology 2022年第3期7卷 340-353页

作者： Jiay.ng Che Xiangrong Tong lei yu School of Computer and Control Engineering Yantai UniversityYantaiShandongChina Department of Computer Science State University of New York at BinghamtonBinghamtonNew YorkUSA

Online social networks greatly promote peoples'online interaction,where trust plays a crucial *** prediction with trust path search is widely used to help users find the trusted friends and obtain valid ***,the shortcomings of accuracy and time still exist in some famous ***,the dynamic bidirectional heuristic search(DBHS)algorithm is proposed in this paper to find the reliable trust path by study.ng the heuristic ***,the trust value and path length are comprehensively considered to find the most trusted ***,it constrains the traversal depth based on the‘small world’theory and obtains the acceptable path set by using the relaxation coefficientλto relax the depth of the shortest *** this way,some longer path with the higher trust can be considered to improve the precision of ***,an adjustment factor is designed based on the meet in the middle(MM)algorithm to assign search weights to two directions based on the size of the search tree expanded,so as to improve the problem of no priori when fixed parameters are ***,the complexity of unidirectional trust path search can also be reduced by searching from two directions,which can reduce the depth and improve the efficiency of ***,the predictive trust degree is outputted by the trust propagation *** public datasets are used to generate experimental results,which show that DBHS can quickly search and form reliable trust relationship,and it partly improves other algorithms.

关键词： directions algorithm dynamic

The classification and assessment of vulnerability of man-land system of oasis city in arid area

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Frontiers of Earth Science 2013年第4期7卷 406-416页

作者： Chao GAO Jun lei Fengjun JIN Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Science Beijing 100101 China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of Science Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China

Oasis city system is the center of the man-land relationship in arid area and it is the most influential spatial and temporal multiple dynamic system. Oasis city system is not only the largest area where artificial disturbances occur at a regional scale but also the most concentrated area of human activity in arid area. In this study, we developed an applicable and convenient method to assess vulnerability of man-land system of oasis cities with vulnerability indicator system, respectively evaluating the sensitivity, adaptability and vulnerability of the eco- environment system, the economic system and the social system. The results showed that the sensitivity and vulnerability of oasis cities in Xinjiang, China have significant differences while their adaptability does little. In order to find the inherent differences in the vulnerability of oasis cities, triangle methodology has been adopted to divide Xinjiang oasis cities into five types. Some adaptive developing policies specific for individual cities are also proposed based on their vulnerability type and constrain- ing factors.

关键词： vulnerability sensitivity man-land system,oasis cities arid area

Retrieval of Snow Depth on Sea Ice in the Arctic Using the Fengyun-3B Microwave Radiation Imager

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Journal of Ocean University of China 2019年第3期18卷 580-588页

作者： LI Lele CHEN Haihua GUAN lei College of Information Science and Engineering Ocean University of China

Snow on sea ice is a sensitive indicator of climate change because it plays an important role regulating surface and near surface air temperatures. Given its high albedo and low thermal conductivity, snow cover is considered a key reason for amplified warming in polar regions. This study focuses on retrieving snow depth on sea ice from brightness temperatures recorded by the Microwave Radiation Imager(MWRI) on board the Fengyun(Fy)-3 B satellite. After cross calibration with the Advanced Microwave Scanning Radiometer-EOS(AMSR-E) Level 2 A data from January 1 to May 31, 2011, MWRI brightness temperatures were used to calculate sea ice concentrations based on the Arctic Radiation and Turbulence Interaction Study Sea Ice(ASI) algorithm. Snow depths were derived according to the proportional relationship between snow depth and surface scattering at 18.7 and 36.5 GHz. To eliminate the influence of uncertainties in snow grain sizes and sporadic weather effects, seven-day averaged snow depths were calculated. These results were compared with snow depths from two external data sets, the IceBridge ICDIS4 and AMSR-E Level 3 Sea Ice products. The bias and standard deviation of the differences between the MWRI snow depth and IceBridge data were respectively 1.6 and 3.2 cm for a total of 52 comparisons. Differences between MWRI snow depths and AMSR-E Level 3 products showed biases ranging between-1.01 and-0.58 cm, standard deviations from 3.63 to 4.23 cm, and correlation coefficients from 0.61 to 0.79 for the different months.

关键词： MWRI AMSRE brightness temperature snow depth inter-sensor calibration sea ice concentration

Nonadiabatic Holonomic Quantum Computation Based on Rydberg Ground State Blockade

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Chinese Physics Letters 2024年第4期41卷 25-31页

作者：苏石磊王琛宋佩瑶陈刚 School of Physics Zhengzhou UniversityZhengzhou 450001China

Quantum gates are crucial for quantum computation and quantum information processing. However, their effectiveness is often hindered by systematic errors and decoherence. Therefore, achieving resilient quantum gates to these factors is of great significance. We present a method to construct nonadiabatic holonomic single-and two-qubit gates in a Rydberg ground-state-blockade regime. Our approach utilizes a far-off-resonant technique for the single-qubit gate and a modified Rydberg antiblockade for the two-qubit gate. The reduction of the population of single-and two-excitation Rydberg states and the nonadiabatic holonomic process during the construction of the gates ensure robustness to decoherence and systematic errors, respectively. Numerical results demonstrate the fidelity and robustness of our scheme. The proposed scheme holds promise for future applications in quantum computation and quantum information processing tasks.

关键词： Rydberg quantum holds

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当前城市民族管理的特点、问题及其功能探析

青海民族研究 2011年第3期22卷 37-41页

作者：张小蕾天津社会科学院天津300191

从政府管理角度看,城市民族管理作为城市民族工作的重要组成部分,其在工作部门、工作制度、工作方式等方面形成了自身特点。同时,城市化进程在一定程度上彰显了城市民族管理过程中存在一定的问题。在深入探析当前城市民族管理的特点和... 详细信息

从政府管理角度看,城市民族管理作为城市民族工作的重要组成部分,其在工作部门、工作制度、工作方式等方面形成了自身特点。同时,城市化进程在一定程度上彰显了城市民族管理过程中存在一定的问题。在深入探析当前城市民族管理的特点和问题的基础上,加强民族管理的积极功能能够缓解城市少数民族对城市发展带来的负面影响,这对维护城市民族团结和实现社会和谐都具有重要的实践意义。

关键词：城市:民族管理特点问题功能