检索结果-南通市图书馆

The Fluorination of Boron-Doped Graphene for CF_(x) Cathode with Ultrahigh Energy Density

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2023年第4期6卷 49-57页

作者： Kai Wang Yiyu Feng Lingchen Kong Cong Peng yuanhang Hu Weiyu Li Yu Li Wei Feng School of Material Science and Engineering Tianjin UniversityTianjin 300072China Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin 300072China Institute of Advanced Technology and Equipment Beijing University of Chemical TechnologyBeijing 100029China

The enhancement of the fluorination degree of carbon fluorides(CF_(x))compounds is the most effective method to improve the energy densities of Li/CF_(x)batteries because the specific capacity of CF_(x)is proportional to the molar ratio of F to C atoms(F/C).In this study,B-doped graphene(BG)is prepared by using boric acid as the doping source and then the prepared BG is utilized as the starting material for the preparation of CF_(x).The B-doping enhances the F/C ratio of CF_(x)without hindering the electrochemical activity of the C–F *** the fluorination process,B-containing functional groups are removed from the graphene *** facilitates the formation of a defect-rich graphene matrix,which not only enhances the F/C ratio due to abundant perfluorinated groups at the defective edges but also serves as the active site for extra Li+*** prepared CF_(x)exhibits the maximum specific capacity of 1204 mAh g^(−1),which is 39.2%higher than that of CF_(x)obtained directly from graphene oxide(without B-doping).An unprecedented energy density of 2974 Wh kg^(−1)is achieved for the asprepared CF_(x)samples,which is significantly higher than the theoretically calculated energy density of commercially available fluorinated graphite(2180 Wh kg^(−1)).Therefore,this study demonstrates a great potential of B-doping to realize the ultrahigh energy density of CF_(x)cathodes for practical applications.

关键词： boron doping energy density fluorinated graphene lithium primary battery rate capability

Trends of Regional Precipitation and Their Control Mechanisms during 1979–2013

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2016年第2期33卷 164-174页

作者： Run LIU Shaw Chen LIU Chein-Jung SHIU Jun LI yuanhang ZHANG State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Research Center for Environmental Changes Academia Sinica Department of Atmospheric Science NCU

Trends in precipitation are critical to water resources. Considerable uncertainty remains concerning the trends of regional precipitation in response to global warming and their controlling mechanisms. Here, we use an interannual difference method to derive trends of regional precipitation from GPCP （Global Precipitation Climatology Project） data and MERRA （Modern- Era Retrospective Analysis for Research and Applications） reanalysis in the near-global domain of 60~ S-60~N during a major global warming period of 1979-2013. We find that trends of regional annual precipitation are primarily driven by changes in the top 30% heavy precipitation events, which in turn are controlled by changes in precipitable water in response to global warming, i.e., by thermodynamic processes. Significant drying trends are found in most parts of the U.S. and eastern Canada, the Middle East, and eastern South America, while significant increases in precipitation occur in northern Australia, southern Africa, western India and western China. In addition, as the climate warms there are extensive enhancements and expansions of the three major tropical precipitation centers-the Maritime Continent, Central America, and tropical Africa-leading to the observed widening of Hadley cells and a significant strengthening of the global hydrological cycle.

关键词： regional precipitation global warming water resources

An observation-based perspective of winter haze days in four major polluted regions of China

在线全文

学校读者我要写书评

暂无评论

National Science Review 2019年第3期6卷 515-523页

作者： Lu Mao Run Liu Wenhui Liao Xuemei Wang Min Shao Shaw Chen Liu yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control Beijing Innovation Center for Engineering Science and Advanced Technology College of Environmental Sciences and Engineering Peking University Institute for Environmental and Climate Research Jinan University Guangdong University of Finance

An observation-based approach is used to examine key characteristics of winter haze days in four major polluted regions in China. Major findings in this study are: first, there was no significant trend in the number of winter haze days in most provinces and districts in eastern China from 1973 to 2012, contrary to the 2.5-fold increase in the emissions of particulate matter and its precursors(PM emissions) in the same period of time. Second, meteorological and climate conditions rather than PM emissions are in control of the interannual variabilities and trends of winter haze days. These interannual variabilities(ranging from 24 to 125%) pose a substantial masking effect that must be overcome by any control of PM emissions before its impact becomes statistically detectable. Finally, we find that global warming may have contributed significantly to the trend of winter haze days in eastern China.

关键词： haze visibility global warming

Major reactive species of ambient volatile organic compounds (VOCs) and their sources in Beijing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2005年第Z2期48卷 147-154页

作者： SHAO Min FU Linlin LIU Ying LU Sihua ZHANG yuanhang TANG Xiaoyan State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental SciencesPeking UniversityBeijing 100871China

Volatile organic compounds(VOCs)are important precursors of atmospheric chemical *** a whole mixture,the ambient VOCs show very strong chemical *** on OH radical loss rates in the air,the chemical reactivity of VOCs in Beijing was *** results revealed that alkenes,accounting for only about 15%in the mixing ratio of VOCs,provide nearly 75%of the reactivity of ambient VOCs and the C4 to C5 alkenes were the major reactive species among the *** study of emission characteristics of various VOCs sources indicated that these alkenes are mainly from vehicle exhaust and gasoline *** reduction of alkene species in these two sources will be effective in photochemical pollution control in Beijing.

关键词： alkenes radicals vehicle exhaust gasoline evaporation.

在线全文

学校读者我要写书评

暂无评论

数字化在电网工程党建工作中的应用

Environmentally Tough and Stretchable MXene Organohydrogel with Exceptionally Enhanced Electromagnetic Interference Shielding Performances

中国科技纵横 2024年第1期 20-22页

作者：毛焱夏新华李攀任远航国网浙江省电力有限公司建设分公司浙江杭州 310000 北京洛斯达科技发展有限公司北京 100120

基于电网工程基层党组织建设和工程业务管理需求,以工程"党建+基建"思想为指导,利用数字化、智能化技术手段开展业务管理,进行电网工程建设的党建数字化管理研究和实践.通过构建工程数字化党建的信息管理平台,实现工程党组织和党建活动... 详细信息

基于电网工程基层党组织建设和工程业务管理需求,以工程"党建+基建"思想为指导,利用数字化、智能化技术手段开展业务管理,进行电网工程建设的党建数字化管理研究和实践.通过构建工程数字化党建的信息管理平台,实现工程党组织和党建活动新闻的数字化管理,开展党员责任落实的智慧化管理和应用,以创新的数字模式开展基层党组织建设,助力电网工程高质量建设.

关键词：电网工程党建数字化智慧管理

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第5期14卷 77-91页

作者： yuanhang Yu Peng Yi Wenbin Xu Xin Sun Gao Deng Xiaofang Liu Jianglan Shui Ronghai Yu School of Materials Science and Engineering Beihang UniversityBeijing 100191People’s Republic of China Science and Technology on Optical Radiation Laboratory Beijing Institute of Environmental FeaturesBeijing 100854People’s Republic of China Science and Technology on Electromagnetic Scattering Laboratory Beijing Institute of Environmental FeaturesBeijing 100854People’s Republic of China

Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching-induced shielding performance *** organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ***,a MXene organohydrogel is prepared which is composed of MXene network for electron conduction,binary solvent channels for ion conduction,and abundant solvent-polymer-MXene interfaces for EM wave *** organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing *** effective strategies have been proposed to solve the problems of current organohydrogel shielding *** reasonably controlling the MXene content and the glycerol-water ratio in the gel,MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the ***,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene *** well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices.

关键词： Electromagnetic interference shielding MXene organohydrogel Stretchable conductive film Anti-drying ability Lowtemperature tolerance

水体镉铅铜复合污染对玉蕊生长及元素吸收的影响

在线全文

学校读者我要写书评

暂无评论

华南农业大学学报 2024年第3期45卷 336-343页

作者：彭远航朱洁怡陆洁阮可瑾冯嘉仪黎炜彬刘颂颂曾曙才华南农业大学林学与风景园林学院广东广州510642 广东省东莞市林业局广东东莞523106 广东省东莞市林业科学研究所广东东莞523003

【目的】探究水体Cd-Pb-Cu重金属复合污染对玉蕊Barringtonia racemosa生长和元素吸收的影响,为玉蕊在重金属复合污染湿地修复方面的应用提供理论依据。【方法】以玉蕊为材料,采取室内盆栽试验模拟湿地环境,研究Cd-Pb-Cu复合污染对玉蕊... 详细信息

【目的】探究水体Cd-Pb-Cu重金属复合污染对玉蕊Barringtonia racemosa生长和元素吸收的影响,为玉蕊在重金属复合污染湿地修复方面的应用提供理论依据。【方法】以玉蕊为材料,采取室内盆栽试验模拟湿地环境,研究Cd-Pb-Cu复合污染对玉蕊生长、养分吸收和重金属吸收分配的影响。【结果】玉蕊株高在20 mg·L^(−1)Cd+200 mg·L^(−1)Pb+400 mg·L^(−1)Cu污染水平下受到显著抑制,与CK(无污染)相比减少14.20%,各处理地径生长均未受显著影响;在5 mg·L^(−1)Cd+100 mg·L^(−1)Cu+50 mg·L^(−1)Pb污染水平下玉蕊的总生物量较CK显著增加;玉蕊在各处理下氮磷钾养分含量均与CK无显著差异,但全株各养分元素累积量均显著高于CK;Cd-Pb-Cu复合污染增加了玉蕊全株Cd、Pb、Cu含量和累积量,各部位Cd、Pb、Cu含量和累积量均随污染浓度升高呈先升后降趋势;相关性分析表明,复合污染下K和Cu对玉蕊的株高、环境适应能力的影响比其他元素更明显;综合转移系数和聚类分析表明,玉蕊在10 mg·L^(−1)Cd+100 mg·L^(−1)Pb+200 mg·L^(−1)Cu污染水平下具有更强的重金属富集能力和转移能力。【结论】玉蕊对Cd-Pb-Cu复合污染水体具有较强的适应性和修复潜能,在Cd、Pb、Cu污染湿地的生态修复中有较好应用前景。

关键词：重金属复合污染玉蕊元素吸收湿地生态修复

维普期刊数据库博看期刊

“重组人红细胞生成素制造工艺虚拟仿真实验”课程的建设与实践

在线全文

学校读者我要写书评

暂无评论

生物工程学报 2024年第6期40卷 1950-1962页

作者：冯佳蒋建兰冯远航朱宏吉余林玲赵广荣卢文玉史清洪天津大学化工学院天津300072

针对生物工程类专业制造工艺学习传统模式中存在的问题,本文阐述了“重组人红细胞生成素制造工艺虚拟仿真实验”课程的建设与实践过程。以重组人红细胞生成素药物为载体,将现代生物制造技术与三维信息技术高度融合。阐述了课程的教学理... 详细信息

针对生物工程类专业制造工艺学习传统模式中存在的问题,本文阐述了“重组人红细胞生成素制造工艺虚拟仿真实验”课程的建设与实践过程。以重组人红细胞生成素药物为载体,将现代生物制造技术与三维信息技术高度融合。阐述了课程的教学理念、教学目标、教学内容、实施方式及实验方法和实验交互性操作步骤及考核标准。以学生为中心,创新实验方案设计、教学方法和评价体系,培养学生分析问题、解决复杂生物医药工程实际问题的能力,拓宽学生的思路和视野。

关键词：重组人红细胞生成素虚拟仿真生物工程类教学改革

A review of gas-phase chemical mechanisms commonly used in atmospheric chemistry modelling

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第1期123卷 522-534页

作者： Yanhui Liu Jiayin Li Yufang Ma Ming Zhou Zhaofeng Tan Limin Zeng Keding Lu yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Science and EngineeringPeking UniversityBeijing 100871China Institute of Energy and Climate Research IEK-8:TroposphereForschungszentrum Jülich GmbHJülich 52428Germany

The atmospheric chemical mechanism is an essential component of airshed models used for investigating the chemical behaviors and impacts of *** the first tropospheric chemical mechanism was proposed in the 1960s,various mechanisms including Master Chemical Mechanism(MCM),Carbon Bond Mechanism(CBM),Statewide Air Pollution Research Center(SAPRC)and Regional Atmospheric Chemistry Mechanism(RACM)have been developed for different research *** work summarizes the development and applications of these mechanisms,introduces their compositions and lumping methods,and compares the ways the mechanisms treat radicals with box model *** can reproduce urban pollution events with relatively low cost compared to SAPRC and RACM,whereas the chemical behaviors of radicals and the photochemical production of ozone are described in detail in *** photolysis rates of some oxygenated compounds are low in SAPRC07,which may result in underestimation of radical *** an explicit chemical mechanism,MCM describes the chemical processes of primary pollutants and their oxidation products in *** can be used to investigate certain chemical processes;however,due to its large size,it is rarely used in regional model simulations.A box model case study showed that the chemical behavior of OH and HO_(2)radicals and the production of ozone were well described by all *** and SAPRC underestimated the radical levels for different chemical treatments,leading to low ozone production values in both *** and RACM are widely used in box model studies,while CBM and SAPRC are often selected in regional simulations.

关键词： Atmospheric chemistry Gas-phase chemical mechanism Ozone Box model