检索结果-南通市图书馆

[Advances in molecular networking technology for discovering emerging contaminants and transformation products]

在线全文

学校读者我要写书评

暂无评论

Se pu = Chinese journal of chromatography 2025年第1期43卷 33-42页

作者： Xiao-Mei Tan Yu-Wei zhang Zhao-Yu Jiao Nan-Yang Yu Si Wei State Key Laboratory of Pollution Control & Resource Reuse School of Environment Nanjing University Nanjing 210046 China.

Emerging contaminants and their transformation products are widely distributed in the environment. These pollutants carry unknown risks owing to their persistence, migration, and toxicity. The wide variety and complex structures of these substances render them difficult to identify using only target analysis. Suspect screening analysis can identify more substances than target analysis in a single run. However, this analysis method is based on limited data and cannot meet the growing demand for compound identification, especially for emerging contaminants and their transformation products with unknown information. The development of high-resolution mass spectrometry technology has promoted the applications of nontarget analysis in the environmental field, especially for identifying unknown transformation products. At present, the challenges of nontarget analysis include the difficulty of finding compounds of interest and their transformation products from complex data. Molecular networking calculates the similarity between mass spectra based on an improved cosine similarity algorithm. This method can cluster molecular families with similar structures, achieve visualization and a collection of massive mass spectral datasets, and promote the annotation of pollutants through networks and communities. Molecular networking can globally organize and systematically interpret complex tandem mass spectral datasets, providing a new direction for nontarget analysis. This technology was first used in proteomics and gradually introduced into metabolomics for the discovery of new natural products. Recently, it has been introduced into the environmental field for the study of various man-made chemicals, particularly for the discovery of emerging contaminants and their transformation products. In this paper, we introduce a molecular networking analysis method based on high-resolution tandem mass spectrometry and describe its applications in the nontargeted screening of emerging cont

关键词： emerging contaminants high-resolution tandem mass spectrometry molecular networking transformation products

Epidemiology of esophageal cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第34期19卷 5598-5606页

作者： yuwei zhang Department of Environmental and Occupational Health School of Public Health and Health ServicesThe George Washington University

Esophageal cancer(EsC)is one of the least studied and deadliest cancers worldwide because of its extremely aggressive nature and poor survival *** ranks sixth among all cancers in *** retrospective studies of EsC,smoking,hot tea drinking,red meat consumption,poor oral health,low intake of fresh fruit and vegetables,and low socioeconomic status have been associated with a higher risk of esophageal squamous cell ***’s esophagus is clearly recognized as a risk factor for EsC,and dysplasia remains the only factor useful for identifying patients at increased risk,for the development of esophageal adenocarcinoma in clinical ***,we investigated the epidemiologic patterns and causes of *** population based cancer data from the Surveillance,Epidemiology and End Results Program of the United States;we generated the most up-to-date stage distribution and 5-year relative survival by stage at diagnosis for *** note should be given to the fact that esophageal cancer,mainly adenocarcinoma,is one of the very few cancers that is contributing to increasing death rates(20%)among males in the United *** further explore the mechanism of development of EsC will hopefully decrease the incidence of EsC and improve outcomes.

关键词： Risk factor Barrett’s esophagus Cyclin D1G870A Esophageal neoplasm Susceptibility Polymorphism

Electrochemomechanical performance of porous electrode incorporating binder network

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(Technological Sciences) 2019年第8期62卷 1331-1340页

作者： JI Liang GUO ZhanSheng zhang yuwei Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University Shanghai 200072 China

This paper proposes a theory for the random generation of porous electrodes to study the electrochemomechanical performance of Li-ion batteries. A new model is developed to explore the effects of the binder network and size polydispersity of electrode particles on the mechanical states under galvanostatic and potentiostatic charging. The quantity of binder, connecting position,contact area, and the angle between the binder and electrode particles exert considerable influence on the electrochemomechanical state of the electrode. Debonding at the interface between the binder and electrode particles is highly likely to occur under galvanostatic charging. Under potentiostatic charging, hoop stress experiences complex compressive-tensile conversion along the interface, which is prone to induce wrinkling and failure of the binder. The model and results are expected to be fundamental to studying real commercial porous electrodes in detail.

关键词： Li-ion battery random generation of porous electrodes binder network electrochemo-mechanical coupling diffusioninduced stress

Distributed bearing-based formation control of unmanned aerial vehicle swarm via global orientation estimation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第1期35卷 44-58页

作者： yuwei zhang Xingjian WANG Shaoping WANG Xinyu TIAN A School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800China

Most existing formation control approaches for Unmanned Aerial Vehicle(UAV)swarm assume that global position and global coordinate frame are directly available for each *** extend the application domain,this paper proposes a distributed bearing-based formation control scheme,without any reliance on global position or global coordinate *** interactions among UAVs are described by a directed topology with two-leader *** address the issue of unavailable global coordinate frame,we first present a distributed orientation estimation law for each UAV to determine its orientation under the coordinate frame of the first *** on the orientation estimation,we then design a bearing-based formation control law to globally asymptotically track target moving ***,simulation results are provided to validate the proposed method,which show that the translation,scale and orientation of the formation can be flexibly controlled via two leaders.

关键词： Bearing measurement Formation control Global orientation estimation Two-leader structure Unmanned aerial vehicles

Study on the Problem of Multistage Vaccine Production and Allocation with Capacity Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2023年第5期36卷 2046-2066页

作者： HAN Qianqian zhang yuwei LI Zhenping FANG Yong School of Management and Engineering Capital University of Economics and BusinessBeijing 100070China School of Information Beijing Wuzi UniversityBeijing 101149China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

Vaccination is the best way to build an immune barrier to control a new infectious *** the limited production capacity at the initial stage of vaccine production,the problem of multistage vaccine production and allocation is studied under the policy of free treatment for infected patients by the *** the population and infection rates of different regions and the vaccine production capacity of each stage,an integer programming model is established to minimize the sum of production-and-vaccination cost and treatment cost of infected patients,which is solved by the GUROBI *** correctness of the model is verified by simulation,and the necessity of considering the treatment cost of infected patients in the objective function is further analyzed,which confirmed the correctness of the free treatment policy for patients in China.A heuristic algorithm is designed to solve the large-scale problem and numerical experiments are conducted to verify the efficiency of this ***,based on the sensitivity analysis results of parameters,the optimal vaccine production and allocation strategy are proposed,which provide the decision basis for the government departments to make reasonable vaccine production and vaccination plan.

关键词： Capacity constraints free treatment heuristic algorithm integer programming multistage vaccine production and allocation

Recent progress on single-molecule nanocatalysis based on single-molecule fluorescence microscopy

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2017年第4期62卷 290-301页

作者： yuwei zhang Tao Chen Ping Song Weilin Xu State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Jilin Provincial Key Laboratory of Low Carbon Chemical Power Changchun Institute of Applied ChemistryChinese Academy of SdencesChangchun 130022China Graduate University of Chinese Academy of Sciences Beijing 100049China

Understanding the heterogeneous catalytic properties of nanoparticles is of great significance for the development of high efficient nanocatalysts, but the intrinsic heterogeneities of nanocatalysts were always covered in traditional ensemble studies. This issue can be overcome if one can follow the catalysis of individual nanoparticles in real time. This paper mainly summarizes recent developments in single- molecule nanocatalysis at single particle level in Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. These developments include the revealing of catalytic kinetics of different types （plane ＆ edge） of surface atoms on individual Pd nanocubes, the observing of in situ deactivation of indi- vidual carbon-supported Pt nanoparticles during the electrocatalytic hydrogen-oxidation reaction, and the measurement of catalytic activation energies on single nanocatalysts for both product formation process and dissociation process, etc. These studies further indicate the advantages or unique abilities of single-molecule methods in the studies of nanocatalvsis or even chemical reactions.

关键词： Single-molecule nanocatalysis Single-molecule fluorescence microscopy Activation energy Electrocatalysis Super-resolution imaging

Weakly hydrophobic nanoconfinement by graphene aerogels greatly enhances the reactivity and ambient stability of reactivity of MIL-101-Fe in Fenton-like reaction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第7期14卷 2383-2389页

作者： yuwei zhang Fei Liu Zhichao Yang Jieshu Qian Bingcai Pan Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Research Center for Environmental Nanotechnology(ReCENT) Nanjing UniversityNanjing 210023China

In the pursuit of heterogeneous catalysts with high reactivity,metal organic framework(MOF)nanomaterials have received tremendous ***,many MOF catalysts especially Fe-based MOFs need to be utilized immediately after synthesis or being activated using high temperature,because of the easy loss of reactivity in humid environments resulting from the occupation of active Fe sites by water ***,we describe an inspiring strategy of growing MIL-101-Fe nanoparticles inside the three-dimensional confined space of graphene aerogel(GA),generating shapeable GA/MIL-101-Fe nanocomposite convenient for practical *** to MIL-101-Fe,GA/MIL-101-Fe as catalyst demonstrates much higher reactivity in Fenton-like reaction,attributing to smaller MIL-101-Fe particle size,presence of active Fe(II)sites,and abundant defects in ***,the weakly hydrophobic nature of the composite greatly inhibits the loss of catalytic reactivity after being stored in humid air and accelerates the recovery of reactivity in mild temperature,by resisting the entrance of water molecules and helping to exclude water *** work demonstrates that a delicate design of nanocomposite structure could not only improve the reactivity of the catalytic component,but also overcome its intrinsic drawback by taking advantage of the properties of *** hope this functional nanoconfinement strategy could be extended to more scenarios in other fields.

关键词： nanoconfinement hydrophobicity MIL-101-Fe graphene aerogel Fenton-like reaction

Component uncertainty importance measure in complex multi-state system considering epistemic uncertainties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第12期37卷 31-54页

作者： Rentong CHEN Shaoping WANG Chao zhang Hongyan DUI yuwei zhang Yadong zhang Yang LI School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Department of Energy Politecnico di MilanoMilano 20156Italy Research Institute of Frontier Science Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800China School of Management Zhengzhou UniversityZhengzhou 450001China

Importance measures can be used to identify the vulnerable components in an aviation system at the early design ***,due to lack of knowledge or less available information on the component or system,the epistemic uncertainties may be one of the challenging issues in importance *** addition,the properties of the aircraft system,which are the fundamentals of the component importance measure,including the hierarchy,dependency,randomness,and uncertainty,should be taken into *** solve these problems,this paper proposes the component Uncertainty Integrated Importance Measure(component UIIM)which considers multiple epistemic uncertainties in the complex multi-state *** degradation process for the components is described by a Markov model,and the system reliability model is developed using the Markov hierarchal evidential *** concept of integrated importance measure is then extended into component UIIM to evaluate the component criticality rather than the component state change criticality,from the perspective of system performance.A case study on displacement compensation hydraulic system is presented to show the effectiveness of the proposed uncertainty importance *** results show that the component UIIM can be an effective method for evaluating the component criticality from system performance perspective at the system early design.

关键词： Importance measure Epistemic uncertainty Multi-state system Evidence theory Markov hierarchal evidential network

Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第7期41卷 1450-1462页

作者： Xinming LIN Jiwen FAN yuwei zhang ZJason HOU Pacific Northwest National Laboratory RichlandWA 99354USA Argonne National Laboratory LemontIL 60439USA

Fires,including wildfires,harm air quality and essential public services like transportation,communication,and *** fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective ***,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)*** developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.

关键词： wildfire severe convective storm hailstorm machine learning