检索结果-南通市图书馆

3D Lamellar-Structured Graphene Aerogels for Thermal Interface Composites with High Through-Plane Thermal Conductivity and Fracture Toughness

引用

Nano-Micro Letters 2021年第2期13卷 13-27页

作者： Pengfei Liu xiaofeng Li Peng Min Xiyuan Chang Chao Shu Yun Ding zhong-Zhen Yu Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic-Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Although thermally conductive graphene sheets are efficient in enhancing in-plane thermal conductivities of polymers,the resulting nanocomposites usually exhibit low through-plane thermal conductivities,limiting their application as thermal interface ***,lamellarstructured polyamic acid salt/graphene oxide(PAAS/GO)hybrid aerogels are constructed by bidirectional freezing of PAAS/GO suspension followed by ***,PAAS monomers are polymerized to polyimide(PI),while GO is converted to thermally reduced graphene oxide(RGO)during thermal annealing at 300℃.Final graphitization at 2800℃ converts PI to graphitized carbon with the inductive effect of RGO,and simultaneously,RGO is thermally reduced and healed to high-quality ***,lamellar-structured graphene aerogels with superior through-plane thermal conduction capacity are fabricated for the first time,and its superior through-plane thermal conduction capacity results from its vertically aligned and closely stacked high-quality graphene *** vacuum-assisted impregnation with epoxy,the resultant epoxy composite with 2.30 vol% of graphene exhibits an outstanding through-plane thermal conductivity of as high as 20.0 W m^−1 K^−1,100 times of that of epoxy,with a record-high specific thermal conductivity enhancement of 4310%.Furthermore,the lamellar-structured graphene aerogel endows epoxy with a high fracture toughness,~1.71 times of that of epoxy.

关键词： Anisotropic aerogels Graphene Thermal conductivity Epoxy composites Fracture toughness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient Preconstruction of Three‑Dimensional Graphene Networks for Thermally Conductive Polymer Composites

引用

Nano-Micro Letters 2022年第8期14卷 72-111页

作者： Hao‑Yu Zhao Ming‑Yuan Yu Ji Liu xiaofeng Li Peng Min zhong‑Zhen Yu Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China College of Materials Science and Engineering Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China School of Chemistry CRANN and AMBERTrinity College DublinDublinIreland

Electronic devices generate heat during operation and require efficient thermal management to extend the lifetime and prevent performance *** by its exceptional thermal conductivity,graphene is an ideal functional filler for fabricating thermally conductive polymer composites to provide efficient thermal *** studies have been focusing on constructing graphene networks in polymer composites to achieve high thermal *** with conventional composite fabrications by directly mixing graphene with polymers,preconstruction of three-dimensional graphene networks followed by backfilling polymers represents a promising way to produce composites with higher performances,enabling high manufacturing flexibility and *** this review,we first summarize the factors that affect thermal conductivity of graphene composites and strategies for fabricating highly thermally conductive graphene/polymer ***,we give the reasoning behind using preconstructed three-dimensional graphene networks for fabricating thermally conductive polymer composites and highlight their potential ***,our insight into the existing bottlenecks and opportunities is provided for developing preconstructed porous architectures of graphene and their thermally conductive composites.

关键词： Graphene networks Thermal conductivity Thermal interface materials Phase change composites Anisotropic aerogels

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A novel complex-system-view-based method for system effectiveness analysis: Monotonic indexes space

引用

Science in China(Series F) 2006年第1期49卷 90-102页

作者： HU Jianwen ZHANG Weiming LIU zhong HU xiaofeng SI Guangya C^4ISR Architecture Technology LAB National University of Defense Technology Changsha 410073 China Strategy Simulation Teaching Department National Defense University Beijing 100091 China

Based on the characteristics of the complex system, this paper presents a novel method, the monotonic indexes space method, for the effectiveness analysis of the complex system. First, it presents some basic concepts and assumption such as the monotonic indexes space, monotonic indexes requirement locus, etc. Second, based on the assumption that indexes are monotonic for the requirements, an algorithm is proposed and applied to numerical approximation of monotonic indexes requirement locus with hyperboxes. Third, this paper proposes two algorithms for acquiring intersection of several monotonic indexes requirement locus. Fourth, this paper proposes the monotonic-indexspace based system analysis model such as the system evaluation model, the sensitivity analysis model for indexes. Based on the practical requirement, the concept of fuzzy monotonic indexes requirement locus and the corresponding analysis model are introduced. Finally, this paper applies the above-mentioned models to analyze the effectiveness of a notional anti-stealth-air-defense information system. And the outputs show that the method is promising.

关键词： effectiveness analysis monotonic indexes space monotonic indexes requirement locus fuzzy effectiveness analysis.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparative Analysis of Influence Factors on Arable Land Use Intensity at Farm Household Level:A Case Study Comparing Suyu District of Suqian City and Taixing City,Jiangsu Province,China

引用

Chinese Geographical Science 2012年第5期22卷 556-567页

作者： LU Xiao HUANG Xianjin zhong Taiyang ZHAO xiaofeng CHEN Yingxue GUO Shuiqiong School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China School of Geography and Tourism QuJu Normal University Qufu 273165 China Jiangsu Engineering CenterJbr Land Development and Consolidation Technology Nanjing 210093 China School of Government Nanjing University Nanjing 210093 China

Using data from the farm household survey conducted in 2009,arable land use intensity(ALUI)and its influence factors at farm household level were investigated by the Tobit *** District of Suqian City and Taixing City of Jiansu Province,China were chosen as the regions for *** results show that:1)On the average, the ALUI,labor intensity,yield-increasing input,and labor-saving input are 15 238.14 yuan(RMB)/ha,192 d/ha, 7233.01 yuan/ha,and 2451.32 yuan/ha in the less economically developed Suyu District,and 13 020.65 yuan/ha,181 d/ha,5871.82 yuan/ha,and 2625.97 yuan/ha in more economically developed Taixing *** figures indicate that Suyu District has higher ALUI and labor intensity input but lower labor-saving input.2)Comparing all the influence factors,the total arable land area in available and average plot size have bigger effects on arable land intensive use;to a small degree,family′s non-farm income affects labor intensity,yield-increasing input,and labor-saving input;the yield-increasing input decreases significantly when the householder has higher education attainment;the commercialization rates of agricultural products and the planting proportion of cash crops both have unstable influence on ALUI; the share of arable land rented in has few impacts on labor intensity,yield-increasing input,and labor-saving input. 3)There are no differences found in the internal impact mechanism of influence factors on the arable land intensive use behaviors of farm ***,there are conspicuous disparities in the impact degrees and statistical significance based on varying economic levels.4)Using the results as bases,this study proposes that the government should implement land management and agricultural policies according to local *** these policies should decrease land fragmentation to promote scale management of land and arable land use intensification.

关键词： arable land use intensity (ALUI) labor intensity yield-increasing input labor-saving input comparativeanalysis farm household

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Global Existence and Decay of Solution to Parabolic-Parabolic Keller-Segel Model in R^(d)

引用

Journal of Donghua University(English Edition) 2022年第1期39卷 85-94页

作者： zhong Wenbin LIU xiaofeng College of Science Donghua UniversityShanghai 201620China

We consider the global existence and decay of integral solutions to the parabolic-parabolic Keller-Segel system in *** the one hand,by Banach fixed point theorem and some properties of heat kernel,we prove the local existence and the global existence of integral solutions for the different initial data under some conditions that involve the size of the initial *** the other hand,in the case of global solutions,we obtain their optimal time decay by Gronwall’s lemma.

关键词： Keller-Segel system global existence integral solution local existence optimal time decay rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

激光共聚焦显微镜在蠕形螨检查中的应用

引用

中华眼外伤职业眼病杂志 2020年第11期42卷 867-871页

作者：晏艳霜冯鑫媛张赛赛钟小凤邓新国广州爱尔眼科医院 510080 天津市眼科医院 300015 中山大学中山眼科中心眼科学国家重点实验室广州510060

目的:评价应用激光共聚焦显微镜检查眼部蠕形螨的作用。方法:回顾性研究。选取2018年11月至2019年1月在广州爱尔眼科医院被诊断为干眼的462例作为研究对象。对所有患者均使用普通光学显微镜检查眼部蠕形螨,随机选择20例普通光学显微镜... 详细信息

目的:评价应用激光共聚焦显微镜检查眼部蠕形螨的作用。方法:回顾性研究。选取2018年11月至2019年1月在广州爱尔眼科医院被诊断为干眼的462例作为研究对象。对所有患者均使用普通光学显微镜检查眼部蠕形螨,随机选择20例普通光学显微镜检查眼部蠕形螨双眼阴性患者采用激光共聚焦显微镜检查眼部蠕形螨。观察两种眼部蠕形螨检查方法差异。结果:462例采用光学显微镜检查蠕形螨的干眼患者中,309例阳性,阳性率为66.88%(309/462)。眼部蠕形螨阴性患者经激光共聚焦显微镜检查后,有14例阳性,阳性率为70.00%(14/20)。两种方法阳性检出率差异有统计学意义(Z=3.742,P<0.05)。结论:使用激光共聚焦显微镜检查眼部蠕形螨效果较好,有望作为临床眼部蠕形螨感染诊断的新方法。

关键词：蠕形螨激光共聚焦显微镜睫毛睑板腺

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nucleation and growth of L1_(2)-Al_(3)RE particles in aluminum alloys:A first-principles study

引用

Journal of Rare Earths 2023年第7期41卷 1116-1126,I0005页

作者： Touwen Fan Zixiong Ruan Feng zhong Chaoyang Xie xiaofeng Li Dongchu Chen Pingying Tang Yuanzhi Wu College of Science Hunan Institute of TechnologyHengyang 421002China Research Institute of Automobile Parts Technology Hunan Institute of TechnologyHengyang 421002China School of Materials Science and Engineering North University of Chin1Taiyuan 030051China School of Material Science and Hydrogen Energy Engineering Foshan UniversityFoshan 528001China Key Laboratory of New Electric Functional Materials of Guangxi Colleges and Universities Nanning Normal UniversityNanning 530023China

The internal mechanisms of nucleation and growth of L1_(2)-AI_(3)RE(RE=Sc,Y,La-Lu) second phases in Al alloys were investigated by combining first-principles calculations with quasi-harmonic approximation(QHA).The calculated results show that the diffusion rate D_s and chemical potential AG_V increase with the increase of *** the increase of atomic number,the D_s and the strain energy ΔE_(CS)increase firstly from Sc to La,and then decreases,while the calculated interface energy γ_(α/β) and ΔG_V show opposite *** on above calculated results,the critical nucleation radius R*and coarsening rate K_(LSW) are obtained from the classical nucleation theory(CNT) and LSW model of the Ostwald ripening of particles,*** the increase of atomic number,the R*increases firstly,and then decreases for all planes at finite *** the K_(LSW) shows opposite variation to the R^(*).From this point of view,it is reasonably speculated that Y and later RE elements can replace the expensive Sc for heat-resistance Al *** solubility c_(∞) of particles is usually very small at low temperature,and there is obvious solubility only when the temperature reaches 600 *** surface energies E_(sur) of AI_(3)RE compounds and Al solid solution are respectively larger and smaller than that of pure Al,respectively,except for the surface(001) and(110) of Al_(3)*** all planes,with the increase of atomic number of RE,E_(sur) decreases firstly from Sc to La,and then increases linearly to *** results are helpful for designing high performance heat-resistance Al alloys.

关键词： First-principles calculations Diffusion rate Quasi-harmonic approximation Particle nucleation and growth Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Vertically aligned reduced graphene oxide/Ti_(3)C_(2)T_(x)MXene hybrid hydrogel for highly efficient solar steam generation

引用

Nano Research 2020年第11期13卷 3048-3056页

作者： Wei Li xiaofeng Li Wei Chang Jing Wu Pengfei Liu Jianjun Wang Xi Yao zhong-Zhen Yu State Key Laboratory of Organic-Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China Institute of Chemistry Chinese Academy of SciencesBeijing100190China Department of Biomedical Sciences City University of Hong KongHong Kong999077China Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing100029China

Effective utilization of abundant solar energy for desalination of seawater and purification of wastewater is one of sustainable techniques for production of clean water,helping relieve global water resource ***,we fabricate a vertically aligned reduced graphene oxide/Ti_(3)C_(2)T_(x)MXene(A-RGO/MX)hybrid hydrogel with aligned channels as an independent solar steam generation device for highly efficient solar steam *** vertically aligned channels,generated by a liquid nitrogen-assisted directional-freezing process,not only rapidly transport water upward to the evaporation surface for efficient solar steam generation,but also facilitate multiple reflections of solar light inside the channels for efficient solar light *** deliberate slight reduction endows the RGO with plenty of polar groups,decreasing the water vaporization enthalpy effectively and hence accelerating water evaporation *** MXene sheets,infiltrated inside the A-RGO hydrogel on the basis of Marangoni effect,enhance light absorption capacity and photothermal conversion *** a result,the A-RGO/MX hybrid hydrogel achieves a water evaporation rate of 2.09 kg·m^(−2)·h^(−1)with a high conversion efficiency of 93.5%under 1-sun ***,this photothermal conversion hydrogel rapidly desalinates seawater and purifies wastewater to generate clean water with outstanding ion rejection rates of above 99%for most ions.

关键词： anisotropic hydrogel MXene reduced graphene oxide solar steam generation aligned channels

来源：

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

基于大数据的无线通信技术

引用

中国科学：信息科学 2021年第11期51卷 1946-1964页

作者：梁应敞谭俊杰龚晨张四海朱近康徐正元李云洲钟晓峰周世东张倩倩曹阳葛君刚杨刚电子科技大学智能通信与网络研究中心成都611731 电子科技大学通信抗干扰技术国家级重点实验室成都611731 中国科学技术大学信息科学技术学院合肥230026 中国科学院无线光电通信重点实验室合肥230026 清华大学北京信息科学与技术国家研究中心北京100084 清华大学电子工程系北京100084

随着各类丰富的移动应用普及,可以预见,未来的无线通信系统将需要满足更为苛刻的服务要求,为无线通信技术的发展带来挑战.另一方面,大数据在众多领域的应用取得了令人瞩目的成功.大数据如何赋能无线通信成为学术界和工业界关注的焦点.过... 详细信息

随着各类丰富的移动应用普及,可以预见,未来的无线通信系统将需要满足更为苛刻的服务要求,为无线通信技术的发展带来挑战.另一方面,大数据在众多领域的应用取得了令人瞩目的成功.大数据如何赋能无线通信成为学术界和工业界关注的焦点.过去5年,我们承担了国家自然科学基金"无线通信大数据基础理论与技术研究"重点项目群,致力于研究基于大数据的无线通信技术,探索使用大数据突破无线通信发展瓶颈的新理论和新方法.我们将这类在无线通信中产生、能够服务于无线通信的大数据定义为无线大数据.本文是对项目群的研究和实践结果的总结.具体地,我们首先分析了无线大数据的来源和特征,然后构建了与之匹配的无线知识学习范式、智能无线网络框架以及跨地域、跨机构、多用途、一体化的无线大数据平台,最后提出并验证了基于大数据的无线传播环境分析、无线传输以及无线接入技术,从而为基于大数据的无线通信技术的进一步发展提供基础理论支撑和应用范式.

关键词：无线大数据无线通信系统智能网络资源优化接入控制

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rational design of robust iridium-ceria oxide-carbon nanofibers to boost oxygen evolution reaction in both alkaline and acidic media

引用

Nano Research 2023年第5期16卷 7724-7732页

作者： Xiaojie Chen Wenying Liao Mengxiao zhong Junjie Chen Su Yan Weimo Li Ce Wang Wei Chen xiaofeng Lu Alan G.MacDiarmid Institute College of ChemistryJilin University2699 Qianjin StreetChangchun 130012China Engineering Research Center of Industrial Biocatalysis College of Chemistry and Materials ScienceFujian Normal UniversityFuzhou 350007China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China Academy of Carbon Neutrality of Fujian Normal University Fuzhou 350007China

Anodic oxygen evolution reaction(OER)is essential to participate in diverse renewable energy conversion and storage processes,while most OER electrocatalysts present satisfactory catalytic performance in only alkaline or acidic medium,limiting their practical applications in many ***,we have designed and prepared Ir-CeO_(2)-C nanofibers(NFs)via an electrospinning and a relatively low-temperature calcination strategy for OER application in both alkaline and acidic *** functional theory(DFT)simulations demonstrate the high catalytic active sites of Ir atoms for OER,that the formation of Ir–O bonds at the interface between Ir and CeO_(2)can modulate the electron density of the relevant Ir atoms to promote the OER *** addition,the unique nanofibrous heterostructure increases the exposed active sites and promotes the electrical ***,the prepared Ir-CeO_(2)-C nanofibrous catalyst delivers an excellent OER property in both alkaline and acidic ***,the overpotentials to reach 10 mA·cm^(−2)are only 279 and 283 mV in the alkaline and acidic electrolyte,respectively,with favorable long-term *** addition,the two-electrode overall water splitting set-ups equipped with Ir-CeO_(2)-C NFs as anode and commercial Pt/C as cathode provide a cell voltage of 1.54 and 1.53 V to drive 10 mA·cm^(−2)in the alkaline and acidic electrolyte,respectively,which are much lower than Pt/C||IrO_(2)and lots of transition metal oxides-based *** research presents an efficient means to design OER catalysts with superior properties in both alkaline and acidic solutions.

关键词： iridium ceria oxide electrospinning electrocatalysis oxygen evolution reaction

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：