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Transport of antibiotic resistance plasmids in porous media and the influence of surfactants

Frontiers of Environmental Science & Engineering 2018年第2期12卷 51-60页

作者： Peipei Chen Chaoqi Chen xiqing li Laboratory of Earth Surface Processes College of Urban and Environmental Sciences Peking University Beijing 100871 China Department of Crops and Soil Environmental Sciences Virginia Polytechnic Institute and State University Blacksburg VA 24061 USA

Transport of engineered antibiotic resistance plasmids in porous media has been reported to potentially cause significant spreading of antibiotic resistance in the environment. In this work, transport of an indigenous resistance plasmid pK5 in porous media was investigated through packed column experiments. At identical ionic strengths in CaC12 solutions, the breakthroughs of pK5 from soil columns were very close to those from quartz sand columns, indicating that transport ofpK5 in quartz sand and soil was similar. A similarity in transport behavior was also tbund between pK5 and an engineered plasmid pBR322 that has approximately the same number of base pairs as pK5. The influence of surfactants, a major group of constituents in soil solutions, was examined using an engineered plasmid pcDNA3.1（＋）/myc-His A. The impact of an anionic surfactant, sodium dodecyl sulfate （SDS）, was negligible at concentrations up to 200 rag. L I. Cetyltrimethyl ammonium bromide （CTAB）, a cationic surfactant, was fbund to significantly enhance plasmid adsorption at high concentrations. However~ at environmentally relevant concentrations （〈 I mg. L I）, the effect of this surfactant was also minimal. The negligible impact of surfactants and the similarity between the transport of engineered and indigenous plasmids indicate that under environmentally relevant conditions, indigenous plasmids in soil also have the potential to transport over long distances and lead to the spreading of antibiotic resistance.

关键词： Indigenous plasmid Transport Porous mediaSurfactants

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Monitoring of regional drug abuse through wastewater-based epidemiology—A critical review

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Science China Earth Sciences 2018年第3期61卷 239-255页

作者： lizhou FENG Wei ZHANG xiqing li Anti-Drug Brigade Bureau of Public Safety School of Environment and Natural Resources Renmin University of China Laboratory of Earth Surface Processes College of Urban and Environmental Sciences Peking University

Wastewater-based epidemiology is a new approach to monitor drug abuse. It involves collecting wastewater, analysis of residues of drugs or its metabolites in wastewater, and back-calculation of drug consumption by taking into account wastewater flow, stability of drug target residues in wastewater, and excretion rates of drugs/metabolites. Wastewater-based epidemiology has the advantages of being inexpensive and yielding more consistent and near real-time results. It has the great potential to supplement the existing drug monitoring methods. It can be used to build large-scale(regional, national, or even continental) monitoring networks that would yield spatial patterns and temporal trends in drug abuse. This paper described in detail the principle and procedures of this wastewater-based approach. Application of this approach across the globe was also reviewed. The uncertainties involved in the approach and knowledge gaps were identified. Finally, necessity, benefits, and feasibility to set up nation or province-wide monitoring networks based on wastewater analysis in China were discussed.

关键词： Drug abuse Monitoring Wastewater-based epidemiology Review

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Fatigue Resistance and Failure Behavior of Penetration and Non-Penetration Laser Welded Lap Joints

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Chinese Journal of Mechanical Engineering 2021年第2期34卷 97-106页

作者： Xiangzhong Guo Wei liu xiqing li Haowen Shi Zhikun Song School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

Penetration and non-penetration lap laser welding is the joining method for assembling side facade panels of railway passenger cars,while their fatigue performances and the difference between them are not completely *** this study,the fatigue resistance and failure behavior of penetration 1.5+0.8-P and non-penetration 0.8+1.5-N laser welded lap joints prepared with 0.8 mm and 1.5 mm cold-rolled 301L plates were *** weld beads showed a solidification microstructure of primary ferrite with good thermal cracking resistance,and their hardness was lower than that of the *** 1.5+0.8-P joint exhibited better fatigue resistance to low stress amplitudes,whereas the 0.8+1.5-N joint showed greater resistance to high stress *** failure modes of 0.8+1.5-N and 1.5+0.8-P joints were 1.5 mm and 0.8 mm lower lap plate fracture,respectively,and the primary cracks were initiated at welding fusion lines on the lap *** were long plastic ribs on the penetration plate fracture,but not on the non-penetration plate *** fatigue resistance stresses in the crack initiation area of the penetration and non-penetration plates calculated based on the mean fatigue limits are 408 MPa and 326 MPa,respectively,which can be used as reference stress for the fatigue design of the laser welded *** main reason for the difference in fatigue performance between the two laser welded joints was that the asymmetrical heating in the non-penetration plate thickness resulted in higher residual stress near the welding fusion line.

关键词： Laser welded lap joint Penetration and non-penetration Fatigue resistance Fracture behavior

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Mechanism of ball milled activated carbon in improving the desalination performance of flow-and fixed-electrode in capacitive deionization desalination

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Frontiers of Environmental Science & Engineering 2023年第5期17卷 145-154页

作者： Ge Shen Junjun Ma Jianrui Niu Ruina Zhang Jing Zhang Xiaoju Wang Jie liu Jiarong Gu Ruicheng Chen xiqing li Chun liu College of Environmental Science and Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Pollution Prevention Biotechnology Laboratory of Hebei Province Shijiazhuang 050018China

Capacitive deionization(CDI)is a novel electrochemical water-treatment *** electrode material is an important factor in determining the ion separation *** carbon(AC)is extensively used as an electrode material;however,there are still many deficiencies in commercial *** adopted a simple processing method,ball milling,to produce ball milled AC(BAC)to improve the physical and electrochemical properties of the original AC and desalination *** BAC was characterized in detail and used for membrane capacitive deionization(MCDI)and flow-electrode capacitive deionization(FCDI)electrode *** ball milling,the BAC obtained excellent pore structures and favorable surfaces for ion adsorption,which reduced electron transfer resistance and ion migration resistance in the *** optimal ball-milling time was 10 ***,the improved effects of BAC as fixed electrodes and flow electrodes are different and the related mechanisms are discussed in *** average salt adsorption rates(ASAR)of FCDI and MCDI were improved by 134%and 17%,respectively,and the energy-normalized removal salt(ENRS)were enhanced by 21%and 53%,*** believe that simple,low-cost,and environmentally friendly BAC has great potential for practical engineering applications of FCDI and MCDI.

关键词： Ball-milling Capacitive deionization Fixed electrode Flow electrode

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Study on prediction of noise produced by stern wake-duct-propeller interaction

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Chinese Journal of Acoustics 2010年第2期29卷 152-161页

作者： XIONG Ziying ZHU xiqing liU Xiaolong li Ya China Ship Scientific Research Center Wuxi 214082

The mechanism and prediction methods of low-frequency discrete spectrmu noise of ducted propellers are studied. The acoustic pressure field of ducted propellers is divided into the propeller radiated field and the duct scattered field based on the linear acoustic theory. First of all, the flow field is analyzed with unsteady panel method to get the unsteady force, and then the pressure data are used as the sources for Ffowcs Williams-Hawings formulation to predict the propeller radiated field, meanwhile, the duct scattered field is obtained by Kirchoff integral equation. Through the analysis and calculation of a ducted propeller case, it is found that the duct scattered sound field is a small quantity compared with propeller radiated sound field under low-frequency and short duct condition; Also the predicted discrete spectrum noise level of ducted propellers is compared with that of full-scale propellers by experiment, verifying the predicted results are able to reflect the full-scale propellers＇ discrete spectrum noise level properly.

关键词： In Study on prediction of noise produced by stern wake-duct-propeller interaction

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Clinical Effects of the COVID-19 Pandemic Among the Uninfected Pregnant Women—6 PLADs,China,2019−2020

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China CDC weekly 2021年第10期3卷 199-206页

作者： Bin Wang Hang An Huanqing Hu Wei Zhao Bahabaike Jiangtulu Shuo Wang Jiamei Wang Junxi Chen Manman Long Zewu li Yu Jin Yuhuan li Huiting Chen Tao Xue xiqing li Kexin li Wei Du Suhong Gao Jiangli Di Xiaohong liu Rongwei Ye Zhiwen li Institute of Reproductive and Child Health Peking University/Key Laboratory of Reproductive HealthNational Health Commission of the People’s Republic of ChinaBeijingChina Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityBeijingChina National Center for Women and Children’s Health Chinese Center for Disease Control and PreventionBeijingChina Department of Obstetrics and Gynecology Haidian Maternal and Child Care HospitalBeijingChina College of Urban and Environmental Sciences Peking UniversityBeijingChina Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijingChina Key Laboratory of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghaiChina.

Summary What is already known about this topic?The coronavirus disease 2019(COVID-19)pandemic potentially affected prenatal care quality and maternal and fetal outcomes *** is added by this report?During COVID-19 pandemic period,the rates of caesarean sections(CS)and preterm birth for uninfected pregnant women increased slightly in areas that were relatively severely impacted by the pandemic in China.

关键词： infected fetal globally

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Biological Characterization and Whole Genome Sequencing of a Genotype VII Newcastle Disease Virus Strain

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Animal Husbandry and Feed Science 2018年第5期10卷 300-305,310页

作者： Sun Hualu li xiqing Bi Yunying Yu Zekun li Sifei liu Yang li Mingyi Cui Xianlan Shandong Sinder Technology Co. Ltd.Qingdao 266000China Covenant High School Tacoma WA 98465USA

[Objective] The aim of this paper was to study the genotype, pathogenicity and nucleotide difference between Newcastle disease virus(NDV) isolates and traditional NDV vaccine strain(La Sota). [Method] A suspected NDV strain was isolated from a chicken farm. The isolate was preliminarily determined by HA and HI tests. A pair of primers was designed based on the partial sequence of NDV F gene published in GenBank(accession No. JF950510.1). F gene was amplified by RT-PCR, cloned and sequenced. The sequencing result was compared with the F gene sequences published in GenBank, and the phylogenetic tree was constructed to analyze the genotypes. The pathogenicity of the virus was determined by mean death time(MDT) of chicken embryos, intracerebral pathogenicity index(ICPI) of one-day-old chicks and intravenous pathogenicity index(IVPI) of six-week-old chickens, respectively. Based on the NDV genome sequence published in GenBank(accession No. JF950510.1), nine pairs of primers were designed to amplify the genome sequence of the isolate, and its structure was analyzed. [Result] The length of F gene was about 500 bp, and a NDV strain of genotype VII was isolated. The MDT, ICPI and IVPI were 52.8 h, 1.675 and 2.46, respectively, indicating the isolate was a virulent strain. The whole genome sequence analysis results showed that the full genome length of the isolate was 15 192 bp, which had 6 more nu-cleotides than that of La Sota strain, and the homology between the two strains was 82.8%. [Conclusion] A virulent NDV strain of genotype Ⅶ was isolated, with low homology to La Sota strain in nucleotide sequence.

关键词： Newcastle disease virus(NDV) F gene Virulent strain Whole genome

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高技术产业研发效率研究——基于非合意产出SBM-DEA模型

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经济与管理研究 2017年第7期38卷 105-113页

作者：刘秉镰李锡庆南开大学经济与社会发展研究院南开大学经济学院

本文克服高技术产业研发过程非合意产出难以度量的问题,以未达标专利数量作为非合意产出,对各地区高技术产业的研发效率进行系统测度。研究发现:(1)随着创新要素的大量投入,中国高技术产业的总体研发效率水平却在逐年降低。造成这种现... 详细信息

本文克服高技术产业研发过程非合意产出难以度量的问题,以未达标专利数量作为非合意产出,对各地区高技术产业的研发效率进行系统测度。研究发现:(1)随着创新要素的大量投入,中国高技术产业的总体研发效率水平却在逐年降低。造成这种现象的根本原因在于投入无效率与合意产出无效率,也即投入要素的大量增加并未有效推动创新产出的增加。(2)近年来中国东、中、西部地区高技术产业研发效率均呈现下降趋势,但东部地区技术落差比较高,其技术水平始终处于领先地位。(3)京津冀、长三角、珠三角等地区高技术产业研发效率呈现L型趋势。

关键词：高技术产业研发效率 SBM-DEA模型

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Studies of Correlations between Surface Composition Changes and Ion Bombardment Fluences of Multicomponent Materials

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Journal of Materials Science & Technology 1993年第3期9卷 229-231页

作者： liping ZHENG xiqing XIA Mingyao li Shanghai Institute of Nuclear Research,Academia Sinca,Shanghai,201800,ChinaRisheng li Lab.of Atomic Imaging of Solids,Institute of Metal Research,Academia Sinica,Shenyang,110015,China

Correlations between surface composition changes and ion bombardment fluences were studied for multicomponent materials by using a dynamic Monte Carlo program,including the preferential sputtering and bombardment-induced Gibbsian segregation (BIGS) *** the case of 1 keV KR-^(10)B_(0.02)^(11)B_(0.08) (the most simple multicomponent material system),it is found that the ^(10)B composition enriches at the surface at low fluences but depletes at the surface at high *** the case of 1 keV Ar-Pt_(0.5)Cu_(0.5).it is found that the Cu composition at the topmost surface is always under the bulk composition between zero and high fluences,but the evident composition gradient of Cu(the segregation species) exists in the surface at low *** effects of the preferential sputtering and BIGS processes on above two surface composition profiles are also discussed.

关键词： implantation preferential sputtering BIGS

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京津冀创新体系建设若干问题

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开放导报 2017年第3期 57-59页

作者：李锡庆吕程南开大学经济学院天津300071

本文以京津冀协同创新体系的发展现状为切入点,重点论述三地在协同创新方面存在资源分布不均、协作不足以及市场化程度不高等突出问题,提出加强管理体制顶层设计、推动公共创新平台联合共享、完善三地人才合作协调机制、促进区域创新市... 详细信息

本文以京津冀协同创新体系的发展现状为切入点,重点论述三地在协同创新方面存在资源分布不均、协作不足以及市场化程度不高等突出问题,提出加强管理体制顶层设计、推动公共创新平台联合共享、完善三地人才合作协调机制、促进区域创新市场化建设等对策建议。

关键词：京津冀协同发展区域创新体系协同创新创新共同体

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