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Enabling Highly Efficient k-Means Computations on the SW26010 Many-Core Processor of Sunway TaihuLight

Journal of Computer Science & Technology 2019年第1期34卷 77-93页

作者： Min Li Chao Yang Qiao Sun wen-Jing Ma wen-long cao Yu-long Ao Institute of Software Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Mathematical Sciences Peking UniversityBeijing 100871China Center for Data Science Peking UniversityBeijing 100871China peng Cheng Laboratory Shenzhen 518052China

With the advent of the big data era,the amounts of sampling data and the dimensions of data features are rapidly *** is highly desired to enable fast and efficient clustering of unlabeled samples based on feature similarities. As a fundamental primitive for data clustering,the k-means operation is receiving increasingly more attentions *** achieve high performance k-means computations on modern multi-core/many-core systems,we propose a matrix-based fused framework that can achieve high performance by conducting computations on a distance matrix and at the same time can improve the memory reuse through the fusion of the distance-matrix computation and the nearest centroids *** implement and optimize the parallel k-means algorithm on the SW26010 many-core processor,which is the major horsepower of Sunway *** particular,we design a task mapping strategy for load-balanced task distribution,a data sharing scheme to reduce the memory footprint and a register blocking strategy to increase the data *** techniques such as instruction reordering and double buffering are further applied to improve the sustained *** on block-size tuning and performance modeling are also *** show by experiments on both randomly generated and real-world datasets that our parallel implementation of k-means on SW26010 can sustain a double-precision performance of over 348.1 Gflops,which is 46.9% of the peak performance and 84%of the theoretical performance upper bound on a single core group,and can achieve a nearly ideal scalability to the whole SW26010 processor of four core *** comparisons with the previous state-of-the-art on both CPU and GPU are also provided to show the superiority of our optimized k-means kernel.

关键词： parallel k-means performance optimization SW26010 processor Sunway TaihuLight

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Semi-industrial experimental study on bauxite separation using a cell-column integration process

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International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 7-15页

作者： Ning-ning Zhang Chang-chun Zhou long-fei Cong wen-long cao You Zhou School of Chemical Engineering and Technology China University of Mining & Technology Xuzhou 221116 China Key Laboratory of Coal Processing and Efficient Utilization (Ministry of Education) Xuzhou 221116 China

The cyclonic-static micro-bubble flotation column （FCSMC） is a highly efficient mineral processing equipment. In this study, a cell-column （FCSMC） integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon （A/S） mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of ＂fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns＂. Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-coltmm integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

关键词： bauxite separation flotation flotation columns flotation cells

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Numerical study of the influence of the atmospheric pressure on the thermal environment in the passenger cabin

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Building Simulation 2024年第2期17卷 253-265页

作者： Xin Su Yu Guo Zhengwei long Yi cao Tianjin Key Lab.of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin300072China Shanghai Aircraft Design and Research Institute Jinke RoadPudong DistrictShanghai201210China

The cabin air pressure remains lower than the horizontal atmospheric pressure when the airplane is in *** pressure is one of the parameters that must be taken into consideration while studying the thermal environment of an airplane *** are still no reference values for aircraft cabins despite the fact that numerous studies on low pressure heat transfer have demonstrated the connection between convective heat transfer coefficient(CHTC)and air *** this paper,a correction method for CHTC under low pressure conditions was established by using the dummy heat dissipation in the low-pressure cabin *** this basis,a thermal environment simulation model was developed,then was applied to the simulation of a seven-row aircraft cabin containing 42 passengers,and the CHTC and heat loss of dummy surface in the cabin were ***,the results of PMV calculated by using heat dissipation and air parameters at sampling points were *** results show that the modified CHTC can accurately reflect the cabin thermal environment under low pressure conditions,and the correction of CHTC can be realized by adjusting the turbulent Prandtl number,which is nonlinear correlated with the *** simulation results of the thermal environment in the seven-row cabin show that the CHTC changes by about 42%before and after *** air pressure decreases during take-off,which reduces the average CHTC of the crew surface from 5.09 W/(m^(2)·K)to 4.56 W/(m^(2)·K),but the air temperature rises by about 0.2°C as a *** deviation of PMV results calculated by using simulated heat loss data and using air parameters of measuring points in space is up to 0.5,but the latter is representative for calculating the thermal comfort level of the whole cabin.

关键词： low pressure aircraft cabin simulation heat dissipation convective heat transfer coefficient

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Cation-doped LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode with high rate performance

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Chinese Journal of Chemical Engineering 2024年第6期70卷 139-148页

作者： long Zhang Dongsheng Yang Lilei Miao Chunmeng Zhang Jiexiang Li Jiawei wen Chunxia Wang Tiantian cao Guoyong Huang Shengming Xu College of New Energy and Materials China University of PetroleumBeijing 102249China State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China Beijing Spacecrafts Beijing 100094China SINOPEC Sales Co. Ltd.Beijing 100728China SINOPEC Research Institute of Petroleum Processing Co. LtdBeijing 100083China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Beijing Key Laboratary of Fine Ceramics Tsinghua UniversityBeijing 100084China

The nickel-rich layered cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has high energy density,lower cost and is a promising cathode material currently under ***,its electrochemical and structural stability is poor during *** the many modification methods,cation doping has been consistently proven to be an effective strategy for enhancing electrochemical ***,the NCM811 cathode material was modified by solid-phase reactions with Mg and Al *** addition,the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory(DFT)calculations,and we have extended this approach to other ternary cathode materials with different ratios and obtained universal *** with DFT calculations,the results show that Mg2+occupies the Li+site and reduces the degree of Li^(+)/Ni^(2+) mixture;Al^(3+) acts as a structural support during charging and discharging to prevent structural *** electrochemical properties were tested by an electrochemical workstation and the LAND system,and the results showed that the capacity retention rate increased to varying degrees from 63.66%to 69.87%and 89.05%for NCM811-Mg and NCM811-Al at room temperature after 300 cycles,*** study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

关键词： Li-ion batteries Cathode materials Doped Electrochemical properties DFT calculation

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Fixed-Time Gradient Flows for Solving Constrained Optimization: A Unified Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1849-1864页

作者： Xinli Shi Xiangping Xu Guanghui wen Jinde cao School of Cyber Science and Engineering Southeast UniversityNanjing 210096China School of Mathematics Southeast UniversityNanjing 210096China

The accelerated method in solving optimization problems has always been an absorbing *** on the fixedtime(FxT)stability of nonlinear dynamical systems,we provide a unified approach for designing FxT gradient flows(FxTGFs).First,a general class of nonlinear functions in designing FxTGFs is provided.A unified method for designing first-order FxTGFs is shown under Polyak-Łjasiewicz inequality assumption,a weaker condition than strong *** there exist both bounded and vanishing disturbances in the gradient flow,a specific class of nonsmooth robust FxTGFs with disturbance rejection is *** the strict convexity assumption,Newton-based FxTGFs is given and further extended to solve time-varying ***,the proposed FxTGFs are further used for solving equation-constrained ***,an FxT proximal gradient flow with a wide range of parameters is provided for solving nonsmooth composite *** show the effectiveness of various FxTGFs,the static regret analyses for several typical FxTGFs are also provided in ***,the proposed FxTGFs are applied to solve two network problems,i.e.,the network consensus problem and solving a system linear equations,respectively,from the perspective of ***,by choosing component-wisely sign-preserving functions,these problems can be solved in a distributed way,which extends the existing *** accelerated convergence and robustness of the proposed FxTGFs are validated in several numerical examples stemming from practical applications.

关键词： Consensus constrained optimization disturbance rejection linear equations fixed-time gradient flow(FxTGF).

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E2F-1 overexpression inhibits human gastric cancer MGC-803 cell growth in vivo

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World Journal of Gastroenterology 2015年第2期21卷 491-501页

作者： Wei-Yuan Wei Lin-Hai Yan Xiao-Tong Wang Lei Li wen-long cao Xiao-Shi Zhang Ze-Xu Zhan Han Yu Yu-Bo Xie Qiang Xiao Department of Surgery The First Affiliated Hospital of Guangxi Medical University Department of Surgery People’s Hospital of Guangxi Zhuang Autonomous Region Department of Anaesthesiology The First Affiliated Hospital of Guangxi Medical University

AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 cells in nude mice, and then tumor growth was investigated. Overexpression of transcription factor E2F-1 was assessed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting analysis. Apoptosis rates were determined using a terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) assay. Expression levels of certain cell cycle regulators and apoptosis-related proteins, such as Bax, survivin, Bcl-2, cyclin D1, S-phase kinaseassociated protein 2, and c-Myc were examined by Western blotting and RT-PCR. RESULTS: Xenograft tumors of MGC-803 cells in nude mice injected with E2F-1 recombinant lentiviral vectors stably overexpressed the E2F-1 gene as measured by semi-quantitative RT-PCR(relative m RNA expression: 0.10 ± 0.02 vs 0.05 ± 0.02 for control vector and 0.06 ± 0.03 for no infection; both P < 0.01) and Western blotting(relative protein expression: 1.90 ± 0.05 vs 1.10 ± 0.03 in control vector infected and 1.11 ± 0.02 for no infection; both P < 0.01). The growth-curve of tumor volumes revealed that infection with E2F-1 recombinant lentiviral vectors significantly inhibited the growth of human GC xenografts(2.81 ± 1.02 vs 6.18 ± 1.15 in control vector infected and 5.87 ± 1.23 with no infection; both P < 0.05) at 15 d after treatment. TUNEL analysis demonstrated that E2F-1 overexpression promoted tumor cell apoptosis(18.6% ± 2.3% vs 6.7% ± 1.2% in control vector infected 6.3% ± 1.2% for no infection; both P < 0.05). Furthermore, lentiviral vector-mediated E2F-1 overexpression increased theexpression of Bax and suppressed survivin, Bcl-2, cyclin D1, Skp2, and c-Myc expression in tumor ***: E2F-1 inhibits growth of GC cells via regulating multiple signaling pathways, and may play an important ro

关键词： E2F-1 Gastric cancer Lentiviral vector Mouse model

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Electronegativity-assisted optimized electronic structure of functionalized-Pt catalysts for boosting oxygen reduction kinetics

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Rare Metals 2024年第5期43卷 1965-1976页

作者： Jin long Kai-wen Zhuang Wei Liao Yan An Bin Wang Chen-Zhong Wu Jian-Xin cao Qing Wang Jun-Song Chen Qing-Mei Wang Guizhou University Key Laboratory of Green Chemical and Clean Energy Technology School of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025China Guizhou University Engineering Research Center of Effcient Utilization for Industrial Waste Guizhou UniversityGuiyang 550025China Institute of Dual-Carbon and New Energy Technology Innovation and Development of Guizhou Province Guiyang 550025China Department of Dermatology West China HospitalSichuan UniversityChengdu610041China Institute for Catalysis Hokkaido UniversitySapporo 001-0021Japan School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu 610106China

Opportunity to harmonize aspects of oxygen reduction reaction(ORR)performance and structure,and morphology,as well as composition,is urgent for the commercialization of proton exchange membrane fuel ***,we demonstrate the design and synthesis of a functionalized-supported-Pt catalyst(Pt@HNC)featuring a hollow nitrogen-modified dodecahedral carbon substrate obtained by a stress-induced-shrink tailoring *** as-obtained Pt@HNC catalyst possesses enhanced ORR per-formance,in particular with half-wave potential,mass activity(MA)and specific activity,which greatly exceed the commercial Pt/*** density functional theory(DFT)calculations further confirmed that the charge redistribution induced by the electronegativity differences improved the electron interaction between Pt and HNC *** optimized electronic structure of Pt weakens the reaction energy barrier on the Pt@HNC surface and adsorption of^(*)OH species,thus cooperatively improving the intrinsic activity toward ***,our work indeed provides a guide for the future design of functional nanomaterials in the field of catalysts and clean energy.

关键词： Proton exchange membrane fuel cell(PEMFC) Oxygen reduction catalysis Supported Pt-based catalyst Stability

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Effects of surface morphology on tribological properties of Arapaima gigas scales

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Friction 2024年第7期12卷 1469-1482页

作者： Shuaijun ZHANG Pengpeng BAI Xiangli wen Chengwei wen Hui cao Wanyou YANG Yu TIAN State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Bionic Engineering(Ministry of Education China)Jilin UniversityChangchun 130022China

The remarkable mechanical adaptability of arapaima(Arapaima gigas)scales has made them an important subject of ***,no research has been conducted into their tribological properties,which are crucial for the protectability and flexibility of *** this study,by combining morphological characterizations,friction experiments,and theoretical analyses,the relationship between the surface morphology and tribological properties of arapaima scales is *** results indicate that arapaima scales exhibit varying surface morphologies in different *** specifically,the exposed regions of scales feature grooves and a circulus,whereas the covered regions exhibit *** specific surface morphology of arapaima scales produces varying tribological properties across different regions and sliding *** unique tribological properties of arapaima scales influence the forces received from predator attacks and neighboring scales,directly influencing the arapaima’s protective *** study provides new insights into the mechanisms of natural flexible dermal armors,and it has potential applications in personal protective systems.

关键词： arapaima scales surface morphology tribological properties protectability

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Online Monitoring Method for Junction Temperature of SiC MOSFETs based on Temperature Sensitive Electrical Parameter

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1799-1807页

作者： Han cao Puqi Ning Yunhao Huang Xuhui wen Wuhan Second Ship Design and Research Institute Wuhan 430205China Key Laboratory of Power Electronics and Electric Drive Institute of Electrical EngineeringChinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081China

Compared to Si devices,the junction temperature of SiC devices is more critical due to the reliability concern introduced by immature packaging technology applied to new *** paper proposes a practical SiC MOSFET junction temperature monitoring method based on the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$*** Section II of the paper,the temperature sensitivity of the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$is *** hardware of the measurement system is set up in Section III,which consists of an On-state Voltage Measurement Circuit(OVMC),the sampling and isolation ***,a calibration method based on the self-heating of the SiC MOSFET chip is presented in Section *** the final Section,the junction temperature is monitored synchronously according to the calibration *** proposed method is applied to a Buck converter and verified by both an Infrared Radiation(IR)camera and a Finite Element Analysis(FEA)tool.

关键词： Junction temperature Silicon Carbide(SiC)MOSFET TSEP

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Biological sources, paleoenvironment, and organic matter enrichment in source rocks of the Ordovician Majiagou Formation, Ordos Basin, China:Evidence from biomarkers,microfossils, and inorganic geochemical analyses

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Journal of Palaeogeography 2024年第1期13卷 92-115页

作者： Jing-Jing cao wen-Zhe Gang Shang-Ru Yang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Bejing)Beijing 102249China College of Geosciences China University of Petroleum(Bejing)Beijing 102249China Oil and Gas Technology Research Institute PetroChina Changqing Oifield CompanyXi'an 710018Shaanxi ProvinceChina

Carbonate deposits in the Ordovivian Majiagou Formation are significant source rocks for natural gas generation in the Ordos Basin, northwestern China. Previous studies mainly focused on the organic matter enrichment mechanism of shales rather than carbonate rocks. The biological sources and paleoenvironment of carbonate source rocks, and the main controlling factors of organic matter enrichment in the carbonate source rocks were studied in this paper in combination with evidence from biomarkers, microfossils and inorganic geochemistry analysis. The results show that four types of microfacies were identified in the Majiagou Formation, respectively as: mud flat microfacies, mud-dolomite flat microfacies, dolomite flat microfacies, and open marine microfacies. The biological sources of organic matter are chiefly planktonic algae, followed by bacteria. The mud flat and mud-dolomite flat contain a high abundance of terrigenous detrital inputs, as indicated by the high content of Al_(2)O_(3), TiO_(2), Th, and Zr. The low Sr/Cu and high Rb/Sr values reveal warm and humid paleoclimate conditions in the mud flat and mud-dolomite flat, whereas the dolomite flat and open marine were likely formed in hot and arid paleoclimate conditions. The mud flat and mud-dolomite flat deposits were characterized by high paleoproductivity of the Majiagou Formation. Low Sr/Ba values were found in the mud flat samples, indicating fresh to brackish water condition, whereas samples of other facies have a relatively high degree of salinity. Based on U_(auth), Mo_(auth), Cr_(auth), Co_(auth), δCe, and δEu values, the mud flat microfacies was formed in a suboxic and anoxic environment, whereas the mud-dolomite flat, dolomite flat and open marine microfacies were within dysoxic to oxic conditions. A model of organic matter enrichment in the Majiagou Formation is thus established. The level of terrigenous detrital inputs is the principal factor of organic matter enrichment in the Majiagou Formation,

关键词： Biological source Microfacies Trace elements Organic matter Majiagou Formation Ordos Basin

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