检索结果-南通市图书馆

Unimem: Runtime Data Management on Non-Volatile Memory-BasedHeterogeneous Main Memory for High Performance Computing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2021年第1期36卷 90-109页

作者： Kai Wu Dong Li Department of Electrical Engineering and Computer Science University of California MercedMerced 95343U.S.A.

Non-volatile memory(NVM)provides a scalable and power-efficient solution to replace dynamic random access memory(DRAM)as main memory.However,because of the relatively high latency and low bandwidth of NVM,NVM is often paired with DRAM to build a heterogeneous memory system(HMS).As a result,data objects of the application must be carefully placed to NVM and DRAM for the best performance.In this paper,we introduce a lightweight runtime solution that automatically and transparently manages data placement on HMS without the requirement of hardware modifications and disruptive change to applications.Leveraging online profiling and performance models,the runtime solution characterizes memory access patterns associated with data objects,and minimizes unnecessary data movement.Our runtime solution effectively bridges the performance gap between NVM and DRAM.We demonstrate that using NVM to replace the majority of DRAM can be a feasible solution for future HPC systems with the assistance of a software-based data management.

关键词： data management non-volatile memory runtime system

Low-temperature(NO + O_(2)) adsorption performance of alkaline earth metal-doped C-FDU-15

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第5期33卷 172-184页

作者： Runping wu Qing Ye Kai Wu Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Chemistry and Chemical EngineeringCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China

To improve the removal capacity of NO + O_(2) effectively, the alkaline earth metal-doped order mesoporous carbon(A-C-FDU-15(0.001)(A = Mg, Ca, Sr and Ba)) and Mg-C-FDU-15( x)( x = 0.001-0.003) samples were prepared, and their physicochemical and NO + O_(2) adsorption properties were determined by means of various techniques. The results show that the sequence in(NO + O_(2)) adsorption performance was as follows: Mg-C-FDU-15(0.001)(93.2 mg/g) > Ca-C-FDU-15(0.001)(82.2 mg/g) > Sr-C-FDU-15(0.001)(76.1 mg/g) > Ba-C-FDU-15(0.001)(72.9 mg/g) > C-FDU-15(67.1 mg/g). Among all of the A-C-FDU-15(0.001) samples, Mg-C-FDU-15(0.001) possessed the highest(NO + O_(2)) adsorption capacity(106.2 mg/g). The species of alkaline earth metals and basic sites were important factors determining the adsorption of NO + O_(2) on the A-C-FDU-15( x) samples, and(NO + O_(2)) adsorption on the samples was mainly chemical adsorption. Combined with the results of(NO + O_(2))-temperatureprogrammed desorption((NO + O_(2))-TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS) characterization, we deduced that there were two main pathways of(NO + O_(2)) adsorption: one was first the conversion of NO and O_(2) to NO_(2) and then part of NO_(2) was converted to NO_(2)^(-) and NO_(3)^(-);and the other was the direct oxidation of NO to NO-2 and NO_(3)^(-).

关键词： C-FDU-15 Alkaline earth metal NO+O_(2)adsorption Adsorption mechanism Adsorption kinetics

同方期刊数据库

Translation landscape of SARS-CoV-2 noncanonical subgenomic RNAs

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2022年第6期37卷 813-822页

作者： Kai Wu Dehe Wang Junhao Wang Yu Zhou State Key Laboratory of Virology College of Life SciencesWuhan UniversityWuhan430072China TaiKang Center for Life and Medical Sciences RNA InstituteWuhan UniversityWuhan430072China Institute for Advanced Studies Wuhan UniversityWuhan430072China Frontier Science Center for Immunology and Metabolism Wuhan UniversityWuhan430072China

The ongoing COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with a positive-stranded RNA genome. Current proteomic studies of SARS-CoV-2 mainly focus on the proteins encoded by its genomic RNA(gRNA) or canonical subgenomic RNAs(sgRNAs). Here, we systematically investigated the translation landscape of SARS-CoV-2, especially its noncanonical sgRNAs. We first constructed a strict pipeline, named vipep, for identifying reliable peptides derived from RNA viruses using RNA-seq and mass spectrometry data. We applied vipep to analyze 24 sets of mass spectrometry data related to SARS-CoV-2infection. In addition to known canonical proteins, we identified many noncanonical sgRNA-derived peptides,which stably increase after viral infection. Furthermore, we explored the potential functions of those proteins encoded by noncanonical sgRNAs and found that they can bind to viral RNAs and may have immunogenic activity. The generalized vipep pipeline is applicable to any RNA viruses and these results have expanded the SARSCoV-2 translation map, providing new insights for understanding the functions of SARS-CoV-2 sgRNAs.

关键词： SARS-CoV-2 Subgenomic RNA(sgRNA) Mass spectrometry Translation RNA binding

The feasibility for natural graphite to replace artificial graphite in organic electrolyte with different film-forming additives

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第4期56卷 58-69页

作者： Shaojun Niu Guobin Zhu Kai Wu Honghe Zheng College of Energy Soochow UniversitySuzhou 215006China Contemporary Amperex Technology Limited Ningde 352100China

The feasibility for natural graphite(NG)to replace artificial graphite(AG)in organic electrolytes with different additives are investigated.Although the strong film-forming additives contributes to form robust solid electrolyte interphase(SEI)film on graphite particle surface,great differences in gas evolution,lithium inventory loss and other side reactions are observed.Lithium bis(oxalato)borate(Li BOB)and fluoroethylene carbonate(FEC)are found more effective and the combination shows to be more promising.In the optimized electrolyte,natural graphite anode exhibits excellent long-term cycling capability.After 800 cycles at high temperature,the capacity retention is comparable to that using artificial graphite.The mechanisms for the capacity-fading of the full cells with AG and NG anode are investigated by ICP,SEM and polarization studies.The results shows that NG electrode consumes more active lithium due to the rough surface and larger volume expansion.The rapid capacity-fading in the initial 100 cycles is related to the instability of the SEI film aroused from large volume expansion.The systematic analysis is inspiriting for the development of high performance lithium ion batteries with reduced cost.

关键词： Lithium ion batteries Natural graphite Electrolyte additive Solid electrolyte interphase

Decouple charge transfer reactions in the Li-ion battery

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第5期92卷 759-798页

作者： Yuxuan Bai Qiu-An Huang Kai Wu Jiujun Zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai 200444China Ningde Contemporary Innovation Laboratory Contemporary Amperex Technology Co.LimitedNingde 352100FujianChina

In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is required.Although electrochemical impedance spectroscopy(EIS)is regarded as a powerful diagnosis tool,it is not a direct but an indirect measurement.With respect to this,some critical questions need to be answered:(i)why EIS can reflect the kinetics of charge transfer reactions;(ii)what the inherent logical relationship between impedance models under different physical scenes is;(iii)how charge transfer reactions compete with each other at multiple scales.This work aims at answering these questions via developing a theory framework so as to mitigate the blindness and uncertainty in unveiling charge transfer reactions in LIBs.To systematically answer the above questions,this article is organized into a three-in-one(review,tutorial,and research)type and the following contributions are made:(i)a brief review is given for impedance model development of the LIBs over the past half century;(ii)an open source code toolbox is developed based on the unified impedance model;(iii)the competive mechanisms of charge transfer reactions are unveiled based on the developed EIS-Toolbox@LIB.This work not only clarifies theoretical fundamentals,but also provides an easy-to-use open source code for EIS-Toolbox@LIB to optimize fast charge/discharge,mitigate cycle aging,and improve energy/power density.

关键词： Electrochemical impedance spectroscopy Unified impedance model Charge transfer reactions Solid/electrolyte diffusion Porous electrode EIS-Toolbox@LIB

Influence of aspect ratio and arrangement direction on the shear behavior of ellipsoids

在线全文

学校读者我要写书评

暂无评论

Particuology 2022年第11期70卷 82-94页

作者： Weichen Sun Kai Wu Songyu Liu Xiang Zhang School of Civil Engineering Chongqing UniversityChongqing 400045China School of Transportation Southeast UniversityNanjing 210096China

This work studies the macroscopic and microscopic behaviors of ellipsoids under triaxial tests using 3D discrete element method(DEM)simulation.To avoid the boundary effect,a novel stress servo-controlled periodic boundary condition is proposed to maintain the confining pressure of samples during testing.The shape features of ellipsoids are investigated,including the aspect ratio of elongated/oblate ellipsoids and the initial arrangement directions of ellipsoids.The macroscopic properties of ellipsoidal particle samples,such as the deviatoric stress,volumetric strain,internal friction angle,as well as dilatancy angles are explored.Elongated and oblate ellipsoids with varying aspect ratios are investigated for the occurrence of stick-slips.In addition,it is demonstrated that the initial arrangement direction has a significant impact on the coordination number and contact force chains.The corresponding anisotropy coefficients of the entire contact network are analyzed to probe the microscopic roots of macroscopic behavior.

关键词： DEM Shear Ellipsoid Periodic boundary condition Arrangement direction Aspect ratio

An intercalation-type Li-free cathode with energy density exceeding 550 Wh kg-1

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2023年第3期10卷 56-57页

作者： Kai Wu Wenwei Luo Bo Xu Contemporary Amperex Technology Limited(CATL) Department of Physics Jiangxi Normal University

The development of all-solid-state technologyinvolving Li-free transition-metalbased cathodes and Li-metal anodes has become an emerging trend with regard to solving the energy and safety bottleneck of current Li-ion ...

关键词：

Carbon dioxide adsorption behaviors of aluminum-pillared montmorillonite-supported alkaline earth metals

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2020年第12期32卷 109-117页

作者： Kai Wu Qing Ye Runping wu Sha Chen Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Chemistry and Chemical EngineeringCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China

The Al-pillared montmorillonite-supported alkaline earth metal 5M/Al-PILC(PILC = pillared clay, M = Mg, Ca, Sr, and Ba) and x Mg/Al-PILC( x = 1, 3, 5, and 7 wt.%) samples were prepared using an impregnation method. Physical properties of the materials were determined by means of X-ray diffraction(XRD) and N2 adsorption-desorption, and their CO2 adsorption behaviors were investigated using the thermogravimetric analyzer(TG), CO2 temperatureprogrammed desorption(CO2-TPD), and in situ diffuse reflectance infrared transform spectroscopy(in situ-DRIFTS) techniques. It is shown that 5 Mg/Al-PILC possessed the highest CO2 adsorption capacity(2.559 mmol/g). The characterization results indicate that Alpillaring increased the specific surface area of montmorillonite, which was beneficial for the adsorption of CO2. The CO2 adsorption process on the sample was mainly chemical adsorption, and alkalinity was the main factor influencing its adsorption capacity. The alkalinity of the sample was enhanced by loading an appropriate amount of alkaline earth metal, and the adsorbed CO2 was present in the form of bicarbonate and carbonate. In addition, the 5Mg/Al-PILC sample exhibited an excellent regeneration efficiency. We believe that the outcome of this research would provide a good option for developing highly effective CO2 adsorption materials.

关键词： Montmorillonite Al-pillaring Adsorbent CO2 adsorption Alkaline earth metal

Mechanical behavior analysis of high power commercial lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第6期58卷 315-322页

作者： Ruicheng Shen Shaojun Niu Guobin Zhu Kai Wu Honghe Zheng College of Energy Soochow UniversitySuzhou 215006China Contemporary Amperex Technology Limited Ningde 352100China

In application,lithium-ion cells undergo expansion during cycling.The mechanical behavior and the impact of external stress on lithium-ion battery are important in vehicle application.In this work,18 Ah high power commercial cell with Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)/graphite electrode were adopted.A commercial compress machine was applied to monitor the mechanical characteristics under different stage of charge(SOC),lifetime and initial external force.The dynamic and steady force was obtained and the results show that the dynamic force increases as the SOC increasing,obviously.During the lifetime with high power driving mode,different external force is shown to have a great impact on the long-term cell performance,with higher stresses result in higher capacity decay rates and faster impedance increases.A proper initial external force(900 N)provides lower impedance increasing.Postmortem analysis of the cells with2000 N initial force suggests a close correlation between electrochemistry and mechanics in which higher initial force leads to higher direct current internal resistance(DCIR)increase rate.In addition,for the cell with higher external force,deformation of the cathode and thicker solid electrolyte interface(SEI)film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.In addition,for the cell with higher external force,deformation of the cathode and thicker SEI film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.

关键词： Lithium-ion batteries External mechanical pressure Capacity fade Static pressure Dynamic pressure