检索结果-南通市图书馆

同方期刊数据库

On Maximum Elastic Scheduling in Cloud-Based Data Center Networks for Virtual Machines with the Hose Model

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2019年第1期34卷 185-206页

作者： Shuai-Bing Lu Jie Wu huan-Yang zheng Zhi-Yi Fang College of Computer Science and Technology Jilin UniversityChangchun 13012China Department of Computer and Information Sciences Temple UniversityPhiladelphiaPA19122U.S.A.

With the growing popularity of cloud-based data center networks (DCNs),task resource allocation has become more and more important to the efficient use of resource in *** paper considers provisioning the maximum admissible load (MAL)of virtual machines (VMs)in physical machines (PMs)with underlying tree-structured DCNs using the hose model for *** limitation of static load distribution is that it assigns tasks to nodes in a once-and-for-all manner,and thus requires a priori knowledge of program *** avoid load redistribution during runtime when the load grows,we introduce maximum elasticity scheduling,which has the maximum growth potential subject to the node and link *** paper aims to find the schedule with the maximum elasticity across nodes and *** first propose a distributed linear solution based on message passing,and we discuss several properties and extensions of the *** on the assumptions and conclusions,we extend it to the multiple paths case with a fat tree DCN,and discuss the optimal solution for computing the MAL with both computation and communication *** that,we present the provision scheme with the maximum elasticity for the VMs,which comes with provable optimality guarantee for a fixed flow scheduling strategy in a fat tree *** conduct the evaluations on our testbed and present various simulation results by comparing the proposed maximum elastic scheduling schemes with other *** simulations validate the effectiveness of the proposed policies,and the results are shown from different perspectives to provide solutions based on our research.

关键词： data center network (DCN) cloud distributed algorithm elasticity hose model optimization

A Fuzzy Hierarchical Strategy for Improving Frequency Regulation of Battery Energy Storage System

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 Modern Power Systems and Clean Energy 2021年第4期9卷 689-698页

作者： Kaifeng Wang ying Qiao Lirong Xie Jiaming Li Zongxiang Lu huan Yang School of Electrical Engineering Xinjiang UniversityUrumqiChina State Key Laboratory of Control and Simulation of Power Systems Generation Equipments of Electrical Engineering Tsinghua UniversityBeijingChina

Battery energy storage systems(BESSs)can provide instantaneous support for frequency regulation(FR)because of their fast response ***,purely pursuing a better FR effect calls for continually rapid cycles of BESSs,which shortens their lifetime and deteriorates the operational *** coordinate the lifespan savings and the FR effect,this paper presents a control strategy for the FR of BESSs based on fuzzy logic and hierarchical *** fuzzy logic controller improves the effect of FR by adjusting the charging/discharging power of the BESS with a higher response speed and precision based on the area control error(ACE)signal and the change rate of ACE in a non-linear *** controllers effectively reduce the life loss by optimizing the depth of discharge,which ensures that the state of charge(SOC)of BESS is always in the optimal operating range,and the total FR cost is the lowest at this *** proposed method can achieve the optimal balance between ACE reduction and operational economy of *** effectiveness of the proposed strategy is verified in a two-area power system.

关键词： Battery energy storage system(BESS) frequency regulation(FR) coordinated control strategy optimal depth of discharge charging/discharging threshold

Disordered Rocksalts with Lattice Oxygen Activation as Efficient Oxygen Evolution Electrocatalysts

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2023年第4期29卷 304-312页

作者： zhengli huan Haipeng Fu Xuerong zheng Huiming Ji School of Materials Science and Engineering Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin UniversityTianjin 300072China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China State Key Laboratory of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China

The lattice oxygen oxidation mechanism(LOM)provides an efficient pathway for accelerating the oxygen evolution reaction(OER)in certain electrocatalysts by activating and involving lattice oxygen in the catalytic OER *** investigated the potential of disordered rocksalts as catalysts for accelerating the OER through the LOM process,leveraging their unique metastable Li-O-Li bond *** calculations were employed to predict the catalytic pathways and activities of disordered rocksalts(DRX),such as Li_(1.2)Co_(0.4)Ti_(0.5)O_(2)(LCTO).The results revealed that benefiting from the unhybridized Li-O electronic orbitals and the resulting metastable states of Li-O-Li bonds in DRX,LCTO exhibited a typical LOM pathway,and the lattice oxygen was easily activated and participated in the *** experimental results showed that LCTO exhibited a remarkable pH-dependent OER activity through the LOM pathway,with an overpotential of 241 mV at a current density of 10 mA/cm^(2),and excellent long-term *** work provides a novel chemical space for designing highly active and stable OER electrocatalysts by leveraging the LOM reaction pathway.

关键词： Lattice oxygen oxidation Disordered rocksalts Oxygen evolution reaction Electrocatalysts

Rational construction of hollow nanoboxes for long cycle life alkali metal ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第7期102卷 46-55页

作者： zheng Zhang ying huang Xiang Li Zhiming Zhou MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions School of Natural and Applied SciencesNorthwestern Polytechnical UniversityXi’an 710072China CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of Sciences100 Haike RoadShanghai 201210China

Hollow nanostructures are extremely attractive in energy storage and show broad application *** the preparation method is accompanied by a complicated *** this article,the CoZn-based hol-low nanoboxes with electrochemical synergy are prepared in a simple *** structure can effectively shorten the transmission distance of ions and electrons,and alleviate the volume expansion during the *** particular,bimetallic oxides are rich in oxygen vacancies,providing more active sites for electro-chemical *** addition,the stepwise oxidation-reduction reaction can also improve the volume change of the electrode *** to the kinetic analysis and density functional theory(DFT)calculation,it is confirmed that the synergistic effect of the bimetallic oxide can accelerate the reaction *** on these characteristics,the electrode exhibits stable cycle performance and long cycle life in alkali metal ion batteries,and can provide reversible capacities of 302.1(LIBs,2000 cycles),172.5(SIBs,10000 cycles)and 109.6(PIBs,5000 cycles)mA h g^(-1)at a current density of 1.0 A g^(-1),*** ad-dition,by assembling(LiCoO_(2)//CoZn-O_(2))and(Na_(3)V_(2)(PO_(4))_(3)//CoZn-O_(2))full-cells,the practical application value is *** sharing of this work introduces a simple way to synthesize hollow nanoboxes,and shows excellent electrochemical performance,which can also be expanded in other areas.

关键词： Hollow nanoboxes Bimetallic oxides DFT calculation Alkali metal ion batteries

Enhancing short-term ethanol-type fermentation of waste activated sludge by adding saccharomycetes and the implications for bioenergy and resource recovery

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第3期34卷 179-189页

作者： Linke zheng ying Xu Hui Geng Xiaohu Dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China East China Architecture Design&Research Institute Shanghai 200002China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Ethanol-type sludge fermentation has recently attracted much attention because it can enhance direct interspecies electron transfer and thus improve the anaerobic digestion of waste activated sludge(WAS). In this paper, the enhancement of short-term ethanol-type fermentation of WAS via adding Saccharomyces was investigated. The experimental results show that the maximum ethanol production of 1030.8 ± 20.6 mg/L was achieved, with the optimum fermentation conditions of a p H of 5.1, temperature of 26.0 ℃ and time of 8.0 hr. Although the content of volatile fatty acid(VFA) increased within 10 hr, it is one order of magnitude lower than the content of ethanol, indicating that the VFA generation did not affect the efficient production of ethanol. The analyses of changes in the microbial community during the fermentation process demonstrate that the greatest Saccharomyces activity occurred in the first 8 hr and it can play an important role in ethanol production even at a very low relative abundance. Meanwhile, most typical acid-producing bacteria were inhibited, but the hydrogenotrophic methanogens(i.e., Methanobacterium) were enriched to a certain extent. Further statistical analyses reveal that the Rhodobacter, Thermomonas, Terrimonas and Saccharomyces are responsible for ethanol production during the fermentation. However, these findings not only provide a reference for the development of enhancing ethanol-type fermentation of sludge, but also are expected to provide a new way of thinking for the efficient bioenergy and resource recovery from sludge.

关键词： Anaerobic digestion Sewage sludge Methane production Ethanol production Biodegradability

A war on the cell wall

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2022年第2期15卷 219-221页

作者： Jian Chen huan Chen Fengquan Liu zheng Qing Fu International Genome Center Jiangsu UniversityZhenjiang 212013China Institute of Plant Protection Jiangsu Academy of Agricultural SciencesNanjingJiangsu 210014China Department of Biological Sciences University of South CarolinaColumbiaSC 29208USA

Plant diseases caused by a wide variety of pathogens have had tremendous negative impacts on human *** example,the oomycete pathogen Phytophthora infestans,which causes severe late blight disease on potatoes,triggered the infamous Irish Potato *** prevent such tragedies from happening again and to reduce crop losses,it is imperative to implement effective disease control and management strategies.A deeper and more comprehensive understanding of how plant pathogens cause disease is critical for developing novel and effective strate-gies for controlling plant diseases.

关键词： blight comprehensive controlling

Video-based measurement and data analysis of traffic flow on urban expressways

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

Acta Mechanica Sinica 2011年第3期27卷 346-353页

作者： Xian-Qing zheng zheng Wu Shi-Xiong Xu Ming-Min Guo Zhan-Xi Lin ying-ying Zhang Department of Mechanics and Engineering Science Fudan University 200433 Shanghai China

A new video-based measurement is proposed to collect and investigate traffic flow parameters. The output of the measurement is velocity-headway distance data pairs. Because density can be directly acquired by the reciprocal of headway distance, the data pairs have the advantage of better simultaneity than those from common detectors. By now, over 33 000 pairs of data have been collected from two road sections in the cities of Shanghai and zhengzhou. Through analyzing the video files recording traffic movements on urban expressways, the following issues are studied：laws of vehicle velocity changing with headway distance, proportions of di0erent driving behaviors in the traffic system, and characteristics of traffic flow in snowy days. The results show that the real road traffic is very complex, and factors such as location and climate need to be taken into consideration in the formation of traffic flow models.

关键词： Traffic flow mode - Video-based - Vehicle recog- nition. Driving behavior - Snowy day traffic

Dominant Deformation Mechanisms in Mg–Zn–Ca Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 1973-1982页

作者： Tao ying Mingdi Yu Yiwen Chen huan Zhang Jingya Wang Xiaoqin Zeng National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China

The coaddition of Zn and Ca has great potential to improve the ductility of Mg ***,the mechanical properties of an extruded Mg-Zn-Ca solid-solution alloy were studied by quasi-in situ electron backscatter diffraction(EBSD)-assisted slip trace *** dominant deformation mechanisms of the Mg-Zn-Ca alloy were studied,and the origins of enhanced ductility were systematically *** results indicate that most grains deformed by basal *** addition,multiple non-bas al slip traces were detected(particularly prismatic,pyramidal I,and pyramidal Islip traces),and their activation frequency was promoted with increasing tensile *** enhanced participation of non-basal slip systems is believed to play a critical role in achieving homogeneous plastic deformation,thus effectively promoting the ductility of the Mg-Zn-Ca ***,first-principle calculations revealed that the coaddition of Zn and Ca significantly reduces the unstable stacking fault energy for non-basal slip,which contributes to the activation of non-basal slip systems during plastic deformation.

关键词： Mg-Zn-Ca alloy Non-basal slip activities First-principle calculations Generalized stacking fault energy Deformation mechanisms

Dual-ligand and hard-soft-acid-base strategies to optimize metal-organic framework nanocrystals for stable electrochemical cycling performance

在线全文

学校读者我要写书评

暂无评论

National Science Review 2022年第7期9卷 88-96页

作者： Shasha zheng Yan Sun Huaiguo Xue Pierre Braunstein Wei huang huan Pang School of Chemistry and Chemical Engineering Yangzhou University Institut de Chimie UMR 7177 Universite′ de StrasbourgCNRS State Key Laboratory of Organic Electronics and Information Displays and Institute of Advanced Materials (IAM)Nanjing University of Posts and Telecommunications Frontiers Science Center for Flexible Electronics (FSCFE) MIIT Key Laboratory of Flexible Electronics (KLo FE)Northwestern Polytechnical University

Most metal-organic frameworks(MOFs) hardly maintain their physical and chemical properties after exposure to acidic,neutral,or alkaline aqueous solutions,resulting in insufficient stability,therefore limiting their ***,the design and synthesis of stable size/morphology-controlled MOF nanocrystals is critical but *** this study,dual-ligand and hard-soft-acid-base strategies were used to fabricate a variety of 3D pillared-layer [Ni(thiophene-2,5-dicarboxylate)(4,4’-bipyridine)]nMOF nanocrystals(1D nanofibers,2D nanosheets and 3D aggregates) with controllable morphology by varying the concentration of 4,4’-bipyridine and thus controlling the crystal growth *** to the shorter ion diffusion length,enhanced ele ctron/ion transfer and strong interactions between thiophene-2,5-dicarboxylate and4,4’-bipyridine,the 2D nanosheets showed much larger specific capacitance than 1D nanofibers and 3D aggregates.A single device with an output voltage as high as 3.0 V and exceptional cycling performance(95% of retention after 5000 cycles at 3 mA cm-2) was realized by configuring two aqueous asymmetric super capacitive devices in *** excellent cycling property and charge-discharge mechanism are consistent with the hard-soft-acid-base theory.

关键词： metal-organic framework dual ligand hard-soft-acid-base electrochemical energy storage supercapacitor