检索结果-南通市图书馆

Occupational Stress and Risk Factors Among Workers from Electronic Manufacturing Service Companies in China

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2020年第9期2卷 131-134页

作者： Jin Wang Xiaoman liu Tao li shuang li National Institute of Occupational Health and Poison Control Chinese Center for Disease Control and PreventionBeijingChina

What is already known about this topic?Occupational stress and workplace health have become issues of significant concern for both employees and *** workers from electronic manufacturing services(EMS)industry in China are exposed to increasing occupational hazards and *** the fact that it is a known health risk for psychological and medical disorders,only few studies have investigate the prevalence of occupational stress and risk factors among EMS *** is added by this report?Analysis of data from the EMS industry of Occupational Stress Surveillance Program with a sample of 21,362 participants from 20 EMS *** show that the prevalence of high strain and effort-reward imbalance were 19.5% and 15.8%,respectively,which are significantly differed by selected socio-demographic and job *** who are migrant,or working in the assembly-line position or in shift are exposed to higher stress *** are the implications for public health practice?EMS workers are liable to be at risk for occupational stress and for developing psychological disorders and *** findings of this study contribute to an evidence-base which inform the development and implementation of strategies aimed at reducing occupational stress of EMS workers should be at organizational and individual level.

关键词： injuries occupational companies

Air combat target maneuver trajectory prediction based on robust regularized Volterra series and adaptive ensemble online transfer learning

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

Defence Technology（防务技术） 2023年第2期20卷 187-206页

作者： Xi Zhi-fei Kou Ying-xin li Zhan-wu Lv Yue Xu An li You li shuang-qing Air Force Engineering University No.1 Baling RoadBaqiao DistrictXi'anShaanxi ProvinceChina

Target maneuver trajectory prediction is an important prerequisite for air combat situation awareness and maneuver ***,how to use a large amount of trajectory data generated by air combat confrontation training to achieve real-time and accurate prediction of target maneuver trajectory is an urgent problem to be *** solve this problem,in this paper,a hybrid algorithm based on transfer learning,online learning,ensemble learning,regularization technology,target maneuvering segmentation point recognition algorithm,and Volterra series,abbreviated as AERTrOS-Volterra is ***,the model makes full use of a large number of trajectory sample data generated by air combat confrontation training,and constructs a Tr-Volterra algorithm framework suitable for air combat target maneuver trajectory prediction,which realizes the extraction of effective information from the historical trajectory ***,in order to improve the real-time online prediction accuracy and robustness of the prediction model in complex electromagnetic environments,on the basis of the TrVolterra algorithm framework,a robust regularized online Sequential Volterra prediction model is proposed by integrating online learning method,regularization technology and inverse weighting calculation method based on the priori ***,inspired by the preferable performance of models ensemble,ensemble learning scheme is also incorporated into our proposed algorithm,which adaptively updates the ensemble prediction model according to the performance of the model on real-time samples and the recognition results of target maneuvering segmentation points,including the adaptation of model weights;adaptation of parameters;and dynamic inclusion and removal of *** with many existing time series prediction methods,the newly proposed target maneuver trajectory prediction algorithm can fully mine the prior knowledge contained in the historical data to assist the current predi

关键词： Maneuver trajectory prediction Volterra series Transfer learning Online learning Ensemble learning Robust regularization

Different Summer Rainfall Anomaly Patterns in Northeast China Associated with Two Kinds of El Ni?o Events

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2020年第2期26卷 223-230页

作者： WANG Qin li shuang-lin Civil Aviation Flight University of China GuanghanSichuan 618307 China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 China

The relationship between summer rainfall anomalies in northeast China and two types of El Ni?o events is investigated by using observation data and an atmospheric general circulation model(AGCM).It is shown that,for different types of El Ni?o events,there is different rainfall anomaly pattern in the following *** the following year of a typical El Ni?o event,there are remarkable positive rainfall anomalies in the central-western region of northeast China,whereas the pattern of more rainfall in the south end and less rainfall in the north end of northeast China easily appears in an El Ni?o Modoki *** reason for the distinct difference is that,associated with the different sea surface temperature anomalies(SSTA)along the equatorial Pacific,the large-scale circulation anomalies along east coast of East Asia shift northward in the following summer after El Ni?o Modoki *** by the anomalous anticyclone in Philippine Sea,southwesterly anomalies over eastern China strengthen summer monsoon and bring more water vapor to northeast ***,convergence and updraft is strengthened by the anomalous cyclone right in northeast China in typical El Ni?o *** moisture and atmospheric circulation conditions are favorable for enhanced ***,because of the northward shift,the anomalous anticyclone in the Philippine Sea in typical El Ni?o cases shifts to the south of Japan in Modoki years,and the anomalous cyclone in northeast China in typical El Ni?o cases shifts to the north of northeast China,leading to the"dipole pattern"of rainfall *** to the results of numerical experiments,we further confirm that the tropical SSTA in different types of El Ni?o event can give rise to observed rainfall anomaly patterns in northeast China.

关键词： typical El Niño El Niño Modoki summer rainfall in northeast China AGCM

The Role of Calcium in Mediating SliAAs Expression in Tomato Pedicel Explants

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2010年第7期9卷 980-984页

作者： ZUO Xian-hong XU Tao QI Ming-fang LU shuang-shuang li Jin-hong li Hong GAO Song li Tian-lai Key Laboratory of Protected Horticulture of liaoning Province/College of Horticulture Shenyang Agricultural University Shenyang 110161 P.R. China

In order to illuminate the effect of calcium on the IAA signal transduction,we studied the expression of eight SliAA genes which were up-regulated by calcium during the abscission after short-term（1 h） and long-term（16 h） treatments with calcium,IAA and calcium *** results indicated that calcium induced SliAAs expression in 1 h at low concentration,EGTA affected little SliAAs expression;it also increased IAA-induced transcript level of SliAAs,TFP（named trifluoperazine） decreased most SliAAs expression below the level of calcium combined with IAA-induced expression,except for ***-term treatment of calcium or calcium inhibitors suppressed some SliAAs expression,whereas TFP enhanced all SliAAs ***,SliAA29 was induced by most treatments excluding 16 h EGTA.

关键词： tomato calcium IAA calcium inhibitors SIlAA gene

Comparative Study on Solid-State and Metastable liquid-State Aging for SAC305/Cu Joints

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 629-637页

作者： shuang li Xiao-Wu Hu Wei-Guo Zhang Yu-Long li Xiong-Xin Jiang Key Lab for Robot and Welding Automation of Jiangxi Province Mechanical and Electrical Engineering SchoolNanchang University College of Mechanical and Electronic Engineering Northwest A&F University

In order to study the in?uence of the physical state of solder on the interfacial reaction of dip-soldered Sn-3.0 Ag-0.5 Cu/Cu system, two kinds of experiments were designed, including:(1) solid-state aging between the solder and Cu substrate;(2)liquid-state aging between the metastable supercooled liquid-state solder and Cu substrate. The aging times were 30, 60,120 and 180 min, respectively, and the aging temperature was 8 ℃ lower than the melting point of the Sn-3.0 Ag-0.5 Cu(SAC305) alloy(217 ℃). The experimental data revealed that the physical state of the solder obviously affected the formation of the intermetallic compound(IMC), and resulted in the difference in the diffusion of atoms on the interface between the SAC305 solder and Cu substrate. The IMC interface after aging for 30 min presents unique characteristics compared with that of the sample after dip soldering. The IMC interface of solid-state aged SAC305/Cu couple is relatively planar, while the IMC interface under metastable supercooled liquid-state aging conditions presents scallop-like shape.

关键词： Lead-free solder Supercooling Metastable liquid state Aging Intermetallic compound

Microwave-assisted Catalyzed Synthesis and In vitro Bioactivity Evaluation of Benzimidazoles Bearing Phenolic Hydroxyl

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2021年第3期37卷 639-646页

作者： YAN liuqing FU Jiaxu li shuang ZHANG Jinlong WANG shuang GU Qiang ZHANG Yumin liN Feng College of Chemistry Jilin UniversityChangchun130012P.R.China School of life Sciences Jilin UniversityChangchun130012P.R.China

An efficient and facile method was introduced for the synthesis of benzimidazoles in this *** optimum reaction conditions were determined.A series of benzimidazoles bearing phenolic hydroxyl(2a—2t)were synthesized in moderate to excellent yields starting from differently substituted hydroxyl benzaldehyde and 4-position substituted o-phenylenediamine via nu-cleophilic addition in the presence of catalyst Na2S2O5 under microwave irradiation ***,effects of the catalyst,molar ratio of reactants,reaction temperature and solvent were *** optimal reaction condition was *** effect of DMF and EtOH solvent on the reaction was *** synthesized compounds were characterized by FTIR,HRMS,1H NMR and 13C NMR ***,the bacteriostatic activities of the synthesized compounds were evaluated with ciprofloxacin and itraconazole as a positive control,*** 2b,2n,2q and 2r exhibited some antibacterial *** lowest MIC of antibacterial activity of compound 2b was 32µg/***,the luminescence property of compound 2b was *** antibacterial activity of compound 2b,along with their good fluorescence performance highlighted the potential of these compounds as lead structures and owned fluorescence trace for further study towards the development of novel drugs and functional mechanisms in living organisms.

关键词： Benzimidazole Microwave irradiation Solvent effect Antimicrobial activity Luminescence property

Selective aggregation of membrane proteins by membrane-mediated interactions

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

Science China Chemistry 2014年第12期57卷 1683-1689页

作者： li shuang Yang ZHANG Xian Ren WANG Wen Chuan School of Food and Chemical Engineering Beijing Technology and Business University State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology

There are different types of membrane proteins in a cellular membrane,and most of them must correctly assemble into appropriate clusters for their cellular *** this work,we suggest a physical mechanism for selective aggregation of different membrane proteins without specific protein-protein attraction by dissipative particle dynamics method.A membrane-mediated interaction may result in different protein clusters with ideal mixing,nonideal mixing and demixing of different types of membrane proteins,depending on the extent of the similarity of membrane deformations by those proteins.

关键词： selective aggregation anchored protein transmembrane protein dissipative particle dynamics(DPD)

Evaluation of phytoextracting cadmium and lead by sunflower,ricinus,alfalfa and mustard in hydroponic culture

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第8期19卷 961-967页

作者： NIU Zhi-xin SUN li-na SUN Tie-heng li Yu-shuang WANG Hong Institute of Applied Ecology Chinese Academy of Sciences Shen yang 110016 China Shenyang University Key Laboratory of Environmental Engineering Shenyang 110044 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Soil contaminated with heavy metals cadmium （Cd） and lead （Pb） is hard to be remediated. Phytoremediation may be a feasible method to remove toxic metals from soil, but there are few suitable plants which can hyperaccumulate metals. In this study, Cd and Pb accumulation by four plants including sunflower （Helianthus annuus L.）, mustard （Brassicajuncea L.）, alfalfa （Medicago sativa L.）, ricinus （Ricinus communis L.） in hydroponic cultures was compared. Results showed that these plants could phytoextract heavy metals, the ability of accumulation differed with species, concentrations and categories of heavy metals. Values of BCF （bioconcentration factor） and TF （translocation factor） indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals. Changes on the biomass of plants, pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures. Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals, such as pH and Eh regulations, and so forth.

关键词： phytoextraction heavy metals plants cadmium lead

Unlocking the potential of transdermal drug delivery

在线全文

学校读者我要写书评

暂无评论

International Journal of Smart and Nano Materials 2024年第3期15卷 432-468页

作者： shuang li Jianhao Wu Xiangjun Peng Xi-Qiao Feng Institute of Biomechanics and Medical Engineering Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijingChina

Transdermal drug delivery(TDD)has gained clinical approval over several decades,with extensive research dedicated to novel drug and device *** notable research progress,the mar-ket adoption of TDD devices has not met anticipated levels,with oral administration and injection remaining predominant delivery *** maximize the potential of TDD,we identify bottlenecks hinder-ing its widespread clinical application and propose promising research *** begin by analyzing stringent demands necessary to truly benefit patients,addressing significant challenges in biomechanics,nanomedicine,and flexible ***,we delve into skin anatomy,enhancement strategies,nano-carriers,and their under-lining mechanisms,highlighting the importance and framework of quantitative *** on these discussions,we highlight the core strength of TDD,such as automatic precise administration based on feedback and high delivery efficiencies,especially applicable to localized conditions(e.g.,central nervous system diseases,tumors).Finally,we envision the future of intelligent TDD device and its opera-tion scenario,aiming to steer research efforts toward faster translation of laboratory innovations into widely used products for sufferers.

关键词： Transdermal drug delivery biomechanics nanomedicine flexible electronics