检索结果-南通市图书馆

Data-driven Detection and Identification of Line Parameters with PMU and Unsynchronized SCADA Measurements in Distribution Grids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 261-271页

作者： Jinping sun Qifang Chen Mingchao Xia School of Electrical Engineering Beijing Jiaotong University(BJTU)Beijing 100044China

Line parameters play an important role in the control and management of distribution ***,phasor measurement unit(PMU)systems and supervisory control and data acquisition(SCADA)systems coexist in distribution ***,SCADA and PMU measurements usually do not match each other,resulting in inaccurate detection and identification of line parameters based on *** solve this problem,a data-driven method is *** measurements are taken as samples and PMU measurements as the population.A probability parameter identification index(PPII)is derived to detect the whole line parameter based on the probability density function(PDF)parameters of the *** parameter identification,a power-loss PDF with the PMU time stamps and a power-loss chronological PDF are derived via kernel density estimation(KDE)and a conditional ***,the power-loss samples with the PMU time stamps and chronological correlations are generated by the two PDFs of the power loss via the Metropolis-Hastings(MH)***,using the power-loss samples and PMU current measurements,the line parameters are identified using the total least squares(TLS)*** simulations demonstrate the effectiveness of the proposed method for distribution network line parameter detection and identification.

关键词： Distribution systems line parameter detection and identification probability density function sampling algorithm the time skew of PMU and SCADA measurements

Changes in extreme high temperature warning indicators over China under different global warming levels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 1895-1909页

作者： Yuxia ZHANG Ying sun Ting HU Chinese Academy of Meteorological Sciences Beijing 100081China National Climate Center Laboratory for Climate StudiesChina Meteorological AdministrationBeijing 100081China

High temperature warning indicators play a pivotal role in meteorological departments,serving as crucial criteria for issuing warnings that guide both social production and daily *** their importance,limited studies have explored the relationship between different global warming levels and changes in high temperature warning *** this study,we analyze data from 2,419 meteorological stations over China and utilize the Coupled Model Intercomparison Project Phase 6(CMIP6)models to examine historical changes in high temperature warning indicators used by the China Meteorological *** evaluate model performance and estimate future changes in these indicators using an annual cycle bias correction *** results indicate that since 1961,the number of high temperature days(TX35d and TX40d)and length of season(TX40d and TX40l)with daily maximum temperature reaching or exceeding 35℃ and 40℃ have increased over *** intensity of high temperatures(TXx)has strengthened and the geographical extent affected by high temperatures has *** 2022,the occurrence of 40℃ high temperatures surges,with Eastern China experiencing a two-day increase in TX40d and an extended seasonal length in TX40l by over five *** CMIP6 models have underestimated the high temperature indictors associated with 35℃ during historical periods,notable difference is not observed between the models and observations for TX40d and TX40l,given their rare ***,future projections,after bias correction,indicate that the increasing trends for 35℃ and 40℃ high temperature days and length of season become more pronounced than the raw projection,suggesting a more severe increase than that anticipated *** global warming intensifies,the high temperature days and length of season are projected to increase non-linearly,while the intensity of high temperatures is expected to increase *** every 1℃ increase in global temperature,the intensity is

关键词： Extreme high temperatures Meteorological warning CMIP6 Global warming levels Future projection

Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年第2期13卷 556-567页

作者： Jinchen Li Mengmeng Yuan Nan Meng Hehe Li Jinyuan sun Baoguo sun Key Laboratory of Brewing Molecular Engineering of China Light Industry Beijing Key Laboratory of Flavor ChemistryBeijing Technology&Business UniversityBeijing 100048China

Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic *** influences are imposed on yeast growth and fermentation performances including the formation of secondary *** cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen *** the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being *** review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent *** discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final *** summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile *** gaps will therefore be elucidated for future research.

关键词： Non-Saccharomyces yeasts Nitrogen Fermentation kinetics Nitrogen preference Wine aroma

Numerical study on the use of soft material walls to enhance seismic performance of an existing tunnel

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第2期15卷 90-112页

作者： Qiangqiang sun Menghao Hou Daniel Dias Institute of Geotechnical Engineering College of Civil Engineering and ArchitectureHebei UniversityBaoding 071002China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

Seismic risk is one of the biggest challenges for tunnel safety,and several mitigation techniques have been proposed to enhance the seismic performance of existing *** paper aims to investigate the effectiveness of an innovative approach for reducing the seismic risk of existing tunnels by using soft material walls(SMW)symmetrically installed in the surrounding *** investigation is performed with a two-dimensional numerical model and the effectiveness of SMW in mitigating the seismic-induced lining forces is quantitatively evaluated by reduction *** influences of nonlinear properties of soil,SMW and tunnel lining on the isolation effectiveness are also *** parametric studies show that the computed reduction ratio is strongly affected by the modulus ratio between the SMW and the soil,the wall geometric parameter,and the flexibility *** is more effective for the thick and soft isolation walls that are inserted near a stiff tunnel in the soft *** tunnel seismic response can be reduced by up to 50%for the scenarios ***,the parametric study identifies an optimum normalized depth of SMW and recommends a relation between the maximum isolation effect and the flexibility ***,simple charts are suggested in this work for estimating the isolation effect in specific conditions of the soil and the *** these lines,the results of this work may be used in the seismic retrofitting of an existing tunnel,aiding the preliminary design of the isolation walls.

关键词： Tunnels Earthquakes Seismic analysis Isolation walls Soft material

On the size generalizibility of graph neural networks for learning resource allocation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 239-254页

作者： Jiajun WU Chengjian sun Chenyang YANG Beihang University School of Electronics and Information Engineering

Size generalization is important for learning resource allocation policies in wireless systems with time-varying scales. If a neural network for learning a wireless policy is not generalizable to the size of its input, it has to be re-trained whenever the system scale changes, which hinders its practical use due to the unaffordable training costs. Graph neural networks(GNNs) have been shown with size generalization ability empirically when optimizing resource allocation. Yet, are GNNs naturally size generalizable? In this paper,we argue that GNNs are not always size generalizable for resource allocation. We find that the aggregation and activation functions of the GNNs for learning a class of wireless policies play a key role in their size generalization ability. We take the GNN with the mean aggregator, called mean-GNN, as an example to reveal a size generalization condition. To demonstrate how to satisfy the condition, we learn power and bandwidth allocation policies for ultra-reliable low-latency communications and show that selecting or pretraining the activation function in the output layer of mean-GNN can make the GNN size *** results validate our analysis and evaluate the performance of the learned policies.

关键词： size generalization graph neural networks resource allocation permutation equivariance

Heparin-binding protein as a predictor of mortality in patients with diabetes mellitus and community-acquired pneumonia in intensive care unit:a propensity score matched study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2024年第4期15卷 263-272页

作者： Yuhan sun Baoqing sun Zhigang Ren Mingshan Xue Changju Zhu Qi Liu Translational Medicine Center Department of Emergency Medicinethe First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China State Key Laboratory of Respiratory Disease National Clinical Research Center for Respiratory DiseaseGuangzhou Institute of Respiratory Healththe First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510230China Department of Infectious Disease the First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China Henan Medical Key Laboratory of Emergency and Trauma Research Department of Emergency Medicinethe First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China

BACKGROUND:Patients with diabetes mellitus(DM)are vulnerable to community-acquired pneumonia(CAP),which have a high mortality *** aimed to investigate the value of heparin-binding protein(HBP)as a prognostic marker of mortality in patients with DM and ***:This retrospective study included CAP patients who were tested for HBP at intensive care unit(ICU)admission from January 2019 to April *** were allocated to the DM or non-DM group and paired with propensity score *** characteristics and clinical outcomes up to 90 days were *** primary outcome was the 10-day *** operating characteristic(ROC)curves,Kaplan-Meier analysis,and Cox regression were used for statistical ***:Among 152 enrolled patients,60 pairs were successfully *** was no significant difference in 10-day mortality,while more patients in the DM group died within 28 d(P=0.024)and 90 d(P=0.008).In the DM group,HBP levels at ICU admission were higher in 10-day non-survivors than in 10-day survivors(median 182.21[IQR:55.43-300]ng/ml *** 66.40[IQR:34.13-107.85]ng/mL,P=0.019),and HBP levels could predict the 10-day mortality with an area under the ROC curve of *** cut-off value,sensitivity,and specificity were 160.6 ng/mL,66.7%,and 90.2%,*** Cox regression analysis indicated that HBP was an independent prognostic factor for 10-day(HR 7.196,95%CI:1.596-32.455,P=0.01),28-day(HR 4.381,95%CI:1.449-13.245,P=0.009),and 90-day mortality(HR 4.581,95%CI:1.637-12.819,P=0.004)in patients with ***:Plasma HBP at ICU admission was associated with the 10-day,28-day,and 90-day mortality,and might be a prognostic factor in patients with DM and CAP.

关键词： Community-acquired pneumonia Diabetes mellitus Heparin-binding protein Propensity score match

Assessment of the Characteristics of Demersal Fish Communities Using Species-and Trait-Based Approaches in the Coastal Habitats Along Rongcheng Bay,Shandong Peninsula,China

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第3期23卷 786-796页

作者： YUAN Shunjie sun Xin TU Zhong sun Jie WANG Xianning ZHANG Peidong Key Laboratory of Mariculture(Ocean University of China) Ministry of EducationQingdao 266003China Shandong Fisheries Development and Resource Conservation Center Yantai 264003China

Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem *** this study,we described the spatial-temporal characteristics of demersal fish communities along a coastal habitat in Rongcheng Bay,Shandong Peninsula,China with both species-based and biological trait-based *** field survey was carried out monthly using traps from April to October of 2018,and divided into three seasons(spring:April and May;summer:June,July and August;autumn:September,October and November).The study area included five distinct habitats:seagrass bed,natural rocky reef,bare sand,artificial reef together with natural rocky reef,and artificial reef together with bare *** analyzed the fish communities with three taxonomic diversity indices,including Shannon-Wiener,Simpson,and Pielou Evenness,as well as four functional diversity indices,including FRic,FEve,FDiv,and FDis,based on 7 functional groups which are categorized into 27 *** results showed that there were no significant differences in taxonomic diversity indices among different habitats in the three ***,significant differences were found in the functional richness of fish communities among different habitats in three *** bed represented the highest functional richness in spring and *** study demonstrates that seagrass bed is very important in enhancing the functional diversity of fish communities in a complex *** study also indicates that the combination of taxonomic diversity and functional diversity will provide a more detailed description of the characteristics of fish communities.

关键词： complex habitat biological traits biodiversity fish communities

Analysis of pressure response at an observation well against pressure build-up by early stage of CO_(2)geological storage project

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 470-482页

作者： Qiang sun Kyuro Sasaki Qinxi Dong Zhenni Ye Hui Wang Huan sun School of Civil Engineering and Architecture Hainan UniversityHaikou570228China Faculty of Engineering Kyushu University744 MotookaNishi-kuFukuoka819-0385Japan Key Laboratory of Equipment Safety and Intelligent Technology for Guangzhou Rail Transit System Guangzhou510430China

To ensure a safe and stable CO_(2)storage,pressure responses at an observation well are expected to be an important and useful field monitoring item to estimate the CO_(2)storage behaviors and the aquifer parameters during and after injecting CO_(2),because it can detect whether the injected CO_(2)leaks to the ground surface or the bottom of the *** this study,pressure responses were simulated to present design factors such as well location and pressure transmitter of the observation *** simulations on the pressure response and the time-delay from pressure build-up after CO_(2)injection were conducted by considering aquifer parameters and distance from the CO_(2)injection well to an observation *** measurement resolution of a pressure transmitter installed in the observation well was presented based on numerical simulation results of the pressure response against pressure build-up at the injection well and CO_(2)plume front ***,the pressure response at an observation well was estimated by comparing the numerical simulation results with the curve of CO_(2)saturation and relative *** was also suggested that the analytical solution can be used for the analysis of the pressure response tendency using pressure build-up and dimensionless parameters of hydraulic ***,a criterion was established for selecting a pressure transducer installed at an observation well to monitor the pressure responses with sufficient accuracy and resolution,considering the distance from the injection well and the pressure build-up at the injection well,for future carbon capture and storage(CCS)projects.

关键词： CO_(2)storage Saline aquifer Observation well Pressure response CO_(2)saturation

Lupenone improves motor dysfunction in spinal cord injury mice through inhibiting the inflammasome activation and pyroptosis in microglia via the nuclear factor kappa B pathway

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第8期19卷 1802-1811页

作者： Fudong Li Xiaofei sun Kaiqiang sun Fanqi Kong Xin Jiang Qingjie Kong Department of Orthopedics Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghaiChina Department of Orthopedic Surgery Spine CenterShanghai Changzheng HospitalNaval Medical UniversityShanghaiChina Department of Orthopedic Surgery Naval Medical CenterNaval Medical UniversityShanghaiChina Department of Anesthesiology Shanghai Changzheng HospitalNaval Medical UniversityShanghaiChina

Spinal cord injury-induced motor dysfunction is associated with *** have shown that the triterpenoid lupenone,a natural product found in various plants,has a remarkable anti-inflammatory effect in the context of chronic ***,the effects of lupenone on acute inflammation induced by spinal cord injury remain *** this study,we established an impact-induced mouse model of spinal cord injury,and then treated the injured mice with lupenone(8 mg/kg,twice a day)by intrape ritoneal *** also treated BV2 cells with lipopolysaccharide and adenosine5’-triphosphate to simulate the inflammatory response after spinal cord *** res ults showed that lupenone reduced IKBa activation and p65 nuclear translocation,inhibited NLRP3 inflammasome function by modulating nuclear factor kappa B,and enhanced the conve rsion of proinflammatory M1 mic roglial cells into anti-inflammatory M2 microglial ***,lupenone decreased NLRP3 inflammasome activation,NLRP3-induced mic roglial cell polarization,and microglia pyroptosis by inhibiting the nuclear factor kappa B *** findings suggest that lupenone protects against spinal cord injury by inhibiting inflammasomes.

关键词： inflammasome inflammation lupenone microglia polarization pyroptosis spinal cord injury