检索结果-南通市图书馆

A Server Placement Algorithm for Reducing Risk and Improving Power Utilization in Data Centers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第1期29卷 158-173页

作者： rui Chen Huikang Huang Xiaoxuan luo Weiwei Lin School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China peng Cheng Laboratory Shenzhen 518066China

As the power demand in data centers is increasing,the power capacity of the power supply system has become an essential resource to be *** many data centers use power oversubscription to make full use of the power capacity,there are unavoidable power supply risks associated with ***,how to improve the data center power capacity utilization while ensuring power supply security has become an important *** solve this problem,we first define it and propose a risk evaluation metric called Weighted Power Supply Risk(WPSRisk).Then,a method,named Hybrid Genetic Algorithm with Ant Colony System(HGAACS),is proposed to improve power capacity utilization and reduce power supply risks by optimizing the server placement in the power supply *** uses historical power data of each server to find a better placement solution by population *** possesses not only the remarkable local search ability of Ant Colony System(ACS),but also enhances the global search capability by incorporating genetic operators from Genetic Algorithm(GA).To verify the performance of HGAACS,we experimentally compare it with five other placement *** experimental results show that HGAACS can perform better than other algorithms in both improving power utilization and reducing the riskof powersupply system.

关键词： server placement power utilization power supply risk swarm intelligence algorithm

A new monitoring index for ecological vulnerability and its application in the Yellow River Basin,China from 2000 to 2022

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 Arid Land 2024年第9期16卷 1163-1182页

作者： GUO Bing XU Mei ZHANG rui luo Wei School of Civil Engineering and Geomatics Shandong University of TechnologyZibo 255000China Key Laboratory of Remote Sensing of Gansu Province Heihe Remote Sensing Experimental Research StationNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China North China Institute of Aerospace Engineering Langfang 065000China

The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade ***,the change mechanisms of ecological vulnerability in different sub-regions and periods vary,and the reasons for this variability are yet to be ***,in this study,we proposed a new remote sensing ecological vulnerability index by considering moisture,heat,greenness,dryness,land degradation,and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin,China from 2000 to 2022 and its driving *** results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy,at 86.36%,which indicated a higher applicability in the Yellow River *** 2000 to 2022,the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03,denoting moderate vulnerability *** intensive vulnerability area was the most widely distributed,which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi *** 2000 to 2022,the ecological vulnerability in the Yellow showed an overall stable trend,while that of the central and eastern regions showed an obvious trend of *** gravity center of ecological vulnerability migrated southwest,indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the *** dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index(NDVI)to temperature from 2000 to 2022,and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation,which indicated that the global climate change exerted a more significant impact on regional *** above results could provide decision support for the ecological protection and restoration of the Y

关键词： ecological vulnerability spatio-temporal pattern gravity center migration trajectory interaction factors geodetector green index q-value

维普期刊数据库

The governance technology for blockchain systems:a survey

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第2期18卷 181-197页

作者： Guocheng ZHU Debiao HE Haoyang AN Min luo Cong peng School of Cyber Science and Engineering Wuhan UniversityWuhan 430072China Shandong Provincial Key Laboratory of Computer Networks Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014China

After the Ethereum DAO attack in 2016,which resulted in significant economic losses,blockchain governance has become a prominent research ***,there is a lack of comprehensive and systematic literature review on blockchain *** deeply understand the process of blockchain governance and provide guidance for the future design of the blockchain governance model,we provide an in-depth review of blockchain *** this paper,first we introduce the consensus algorithms currently used in blockchain and relate them to governance ***,we present the main content of off-chain governance and investigate two well-known off-chain governance ***,we investigate four common on-chain governance voting techniques,then summarize the seven attributes that the on-chain governance voting process should meet,and finally analyze four well-known on-chain governance blockchain projects based on the previous *** hope this survey will provide an in-depth insight into the potential development direction of blockchain governance and device future research agenda.

关键词： blockchain governance off-chain governance on-chain governance voting

Rockburst proneness considering energy characteristics and sample shape effects

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 Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2441-2465页

作者： Song luo Fengqiang Gong Kang peng Zhixiang Liu School of Resources and Safety Engineering Central South UniversityChangsha410083China School of Civil Engineering Southeast UniversityNanjing211189China

Accurate prediction of rockburst proneness is one of challenges for assessing the rockburst risk and selecting effective control *** study aims to assess rockburst proneness by considering the energy characteristics and qualitative information during rock *** representative rock types in cylindrical and cuboidal sample shapes were tested under uniaxial compression conditions and the failure progress was detected by a high-speed *** far-field ejection mass ratio(FEMR)was determined considering the qualitative failure information of the rock *** peak-strength energy impact index and the residual elastic energy index were used to quantitatively evaluate the rockburst proneness of both cylindrical and cuboidal ***,the performance of these two indices was analyzed by comparing their estimates with the *** results show that the accuracy of the residual elastic energy index is significantly higher than that of the peak-strength energy impact *** residual elastic energy index and the FEMR are in good agreement for both cylindrical and cuboidal rock *** is because these two indices can essentially reflect the common energy release mechanism characterized by the mass,ejection velocity,and ejection distance of rock *** suggests that both the FEMR and the residual elastic energy index can be used to accurately measure the rockburst proneness of cylindrical and cuboidal samples based on uniaxial compression test.

关键词： Rockburst proneness Sample shape Strain energy Energy release Far-field ejection mass ratio(FEMR)

A combined experimental and DEM investigation of grain interlocking in sheared granular assemblies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 436-451页

作者： rui Lu Qiang luo Tengfei Wang David P.Connolly Tao Xie School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering(Southwest Jiaotong University) Ministry of EducationChengdu 610031China School of Civil Engineering University of LeedsLeeds LS29JTUK Department of Civil Engineering McMaster UniversityHamiltonONCanada

Compacted granular material,integral to geotechnical engineering,undergoes translation,rotation,and interlocking when subject to shear displacements or external *** present study focuses on the interlocking of heterogeneous granular materials,a complex behavior influenced by gradation,compaction,and varying particle geometry,and has consequently received limited attention in existing *** address this research gap,we conducted an analysis on the effect of grain interlocking on the shear resistance of granular assemblies,using a combination of laboratory testing and the discrete element method(DEM).Initially,large-scale direct shear tests were conducted on gravel−sand mixes with varying degrees of compaction and normal *** of the mixes also underwent subsequent shear reversal to explore the differences in grain interlocking between the two shearing processes on the shear *** analyzing the laboratory results,a mesoscopic scale investigation was performed by replicating the test using discrete element *** facilitate this,granular particle geometries were measured using 3D laser scanning based on the physical lab ***,based on these scans,discrete element R-block and ball models were utilized to construct both the coarse and fine particles within the *** vibro-compaction was employed to regulate the degree of *** results indicate that an increase in vertical pressure,coupled with a zero dilatancy angle,results in a rising stress ratio,indicative of grain *** interlocking exhibits a positive correlation with both the coarse content and the degree of compaction,and varies depending on the shear *** interlocking progresses,the shear band,induced by particle movement,expands and is associated with reduced particle rotation near the shear *** study further reveals a consistent positive correlation between interlocking and the principal orientation angle of strong normal c

关键词： Granular material Interlocking Shear resistance Direct shear Discrete element method Vibro-compaction

Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao Qiao Jian Li Xiao-yang luo peng peng Xian-tao Yan Xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

维普期刊数据库

Is recovery enhancement after gastric cancer surgery really a safe approach for elderly patients?

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1334-1343页

作者： Zi-Wei Li Xiao-Juan luo Fei Liu Xu-rui Liu Xin-peng Shu Yue Tong Quan Lv Xiao-Yu Liu Wei Zhang Dong peng Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Endoscopy Center The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400012China

BACKGROUND This study aimed to evaluate the safety of enhanced recovery after surgery(ERAS)in elderly patients with gastric cancer(GC).AIM To evaluate the safety of ERAS in elderly patients with *** The PubMed,EMBASE,and Cochrane Library databases were used to search for eligible studies from inception to April 1,*** mean difference(MD),odds ratio(OR)and 95%confidence interval(95%CI)were pooled for *** quality of the included studies was evaluated using the Newcastle-Ottawa Scale *** used Stata(V.16.0)software for data *** This study consists of six studies involving 878 elderly *** analyzing the clinical outcomes,we found that the ERAS group had shorter postoperative hospital stays(MD=-0.51,I2=0.00%,95%CI=-0.72 to-0.30,P=0.00);earlier times to first flatus(defecation;MD=-0.30,I²=0.00%,95%CI=-0.55 to-0.06,P=0.02);less intestinal obstruction(OR=3.24,I2=0.00%,95%CI=1.07 to 9.78,P=0.04);less nausea and vomiting(OR=4.07,I2=0.00%,95%CI=1.29 to 12.84,P=0.02);and less gastric retention(OR=5.69,I2=2.46%,95%CI=2.00 to 16.20,P=0.00).Our results showed that the conventional group had a greater mortality rate than the ERAS group(OR=0.24,I2=0.00%,95%CI=0.07 to 0.84,P=0.03).However,there was no statistically significant difference in major complications between the ERAS group and the conventional group(OR=0.67,I2=0.00%,95%CI=0.38 to 1.18,P=0.16).CONCLUSION Compared to those with conventional recovery,elderly GC patients who received the ERAS protocol after surgery had a lower risk of mortality.

关键词： Enhanced recovery after surgery Gastric cancer Elderly Mortality

Divergent contributions of spring and autumn photosynthetic phenology to seasonal carbon uptake of subtropical vegetation in China

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 Geographical Sciences 2024年第7期34卷 1280-1296页

作者： peng Ying LI peng ZHOU Xiaolu luo Yunpeng ZHANG Cicheng WANG Longjun LI Tong peng Changhui School of Geographic Sciences Hunan Normal UniversityChangsha410081China Department for Biogeochemical Integration Max-Planck-Institute for BiogeochemistryJena07745Germany Department of Biology Sciences Institute of Environment SciencesUniversity of Quebec at MontrealC.P.8888Succ.Centre-VilleMontrealH3C 3P8Canada

Phenological changes play a central role in regulating seasonal variation in the ecological processes,exerting significant impacts on hydrologic and nutrient cycles,and ultimately influencing ecosystem functioning such as carbon ***,the potential impact mechanisms of phenological events on seasonal carbon dynamics in subtropical regions are *** knowledge gaps hinder from accurately linking photosynthetic phenology and carbon sequestration *** chlorophyll fluorescence remote sensing and productivity data from 2000 to 2019,we found that an advancement in spring phenology increased spring gross(GPP)and net primary productivity(NPP)in subtropical vegetation of China by 2.1 gC m^(-2)yr^(-1)and 1.4 gC m^(-2)yr^(-1),respectively.A delay in autumn phenology increased the autumnal GPP and NPP by 0.4 gC m^(-2)yr^(-1)and 0.2 gC m^(-2)yr^(-1),***,the contribution of the spring phenology to spring carbon uptake increased significantly during the study period,while this positive contribution showed a nonsignificant trend in *** comparison,the later autumn phenology could significantly contribute to the increase in autumnal carbon uptake;however,this contributing effect was *** analysis indicated that these phenomena have been caused by the increased leaf area and enhanced photosynthesis due to earlier spring and later autumn phenology,*** results demonstrate the diverse impacts of vegetation phenology on the seasonal carbon sequestration ability and it is imperative to consider such asymmetric effects when modeling ecosystem processes parameterized under future climate change.

关键词： subtropics vegetation phenology remote sensing carbon cycle climate change

维普期刊数据库

Advances in metal-organic framework-derived single-atom catalysts for biomedicine

在线全文

学校读者我要写书评

暂无评论

Nano Materials Science 2024年第4期6卷 396-412页

作者： Li Qiu Yingxi Lin Jun Song Chen Hong luo rui Wu Department of Ultrasound West China Second University Hospital Sichuan University Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education Sichuan University School of Materials and Energy University of Electronic Science and Technology of China Interdisciplinary Materials Research Center Institute for Advanced Study Chengdu University

As a alternative for natural enzymes, nanozymes has shown enzyme-like activity and selectivity in the field of various kinds of biomedical application, which has attracted considerable research interest. Recently, single-atom catalysts(SACs) have been extensively studied due to their similar active centers, coordination environment and better stability to natural enzymes. Metal-organic frameworks(MOFs) have been demonstrated as highly promising precursors for the synthesis of various types of SACs. MOF-derived SACs can not only significantly enhance the catalytic activity, but also improve the selectivity of nanozymes due to tunable coordination environment and structure, thereby receiving widespread attention in biomedicine. This review provided an overview of the preparation strategies for MOF-derived SACs, and then detailed the latest research progress of the SACs in the biomedical field for cancer, antibacterial, antioxidation and biosensors. Finally, the challenges and potential future opportunities of MOF-derived SACs in biomedical applications are proposed.

关键词： Biomedicine MOF-Derived SAC nanozymes Catalytic mechanisms