检索结果-南通市图书馆

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

引用

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 degradation.Although organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ability.Here,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 scattering.This organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing ability.Two effective strategies have been proposed to solve the problems of current organohydrogel shielding materials.By 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 gel.Moreover,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene nanosheets.This 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

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

Catalysis stability enhancement of Fe/Co dual-atom site via phosphorus coordination for proton exchange membrane fuel cell

引用

Nano Research 2022年第4期15卷 3082-3089页

作者： Yinuo Wang Xin Wan Jieyuan liu Wenwen Li Yongcheng Li Xu Guo xiaofang liu Jiaxiang Shang Jianglan Shui School of Materials Science and Engineering Beihang UniversityBeijing 100081China Qinghai Provincial Key Laboratory of New Light Alloys Qinghai Provincial Engineering Research Center of High-Performance Light Metal Alloys and FormingQinghai UniversityXining 810016China

Non-precious metal catalysts(NPMCs)are promising low-cost alternatives of Pt/C for oxygen reduction reaction(ORR),which however suffer from serious stability challenge in the devices of proton-exchange-membrane fuel cells(PEMFC).Different from the traditional strategies of increasing the degree of graphitization of carbon substrates and using less Fenton-reactive metals,we prove here that proper regulation of coordination anions is also an effective way to improve the stability of NPMC.N/P cocoordinated Fe-Co dual-atomic-sites are constructed on ZIF-8 derived carbon support using a molecular precursor of C_(34)H_(28)Cl_(2)CoFeP_(2)and a“precursor-preselected”method.A composition of FeCoN_(5)P1 is infered for the dual-atom active site by microscopy and spectroscopy analysis.By comparing with N-coordinated references,we investigate the effect of P-coodination on the ORR catalysis of Fe-Co dual-atom catalysts in PEMFC.The metals in FeCoN_(5)P1 have the lower formation energy than those in the solo N-coordinated active sites of FeCoN6 and FeN_(4),and exhibits a much better fuel cell stability.This anion approach provides a new way to improve the stability of dual-atom catalysts.

关键词： fuel cell oxygen reduction reaction non-precious metal catalyst dual atomic site P/N coordination

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

Oriented magnetic liquid metal-filled interlocked bilayer films as multifunctional smart electromagnetic devices

引用

Nano Research 2023年第1期16卷 1764-1772页

作者： Jinjin Li Yue Zhang Xufeng Li Chunyan Chen Haihan Zou Peng Yi xiaofang liu Ronghai Yu School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Smart electromagnetic functional devices prepared based on electromagnetic wave responsive materials will provide more convenience for human life in the future.Here,we prepare oriented magnetic liquid metal droplet-filled polydimethylsiloxane films with micropillar array patterned surfaces,and further assemble them into bilayer films with interlocked structures.Once compressed,the increase in conductivity of the film due to the tunneling effect between microarrays and the elongation of liquid metal droplets leads to a rapid increase in electromagnetic interference shielding performance.Accordingly,a tunable electromagnetic interference shielding material with high sensitivity and wide control range is obtained,which has potential applications in electromagnetic wave control systems and intelligent electromagnetic protection systems.Meanwhile,we assemble a strain sensor and a magnetic sensor,which can precisely sense pressure and magnetic field according to changes in electromagnetic signal and electrical signal,respectively.

关键词： magnetic liquid metal electromagnetic interference shielding interlocked structure electromagnetic sensing magnetic sensing

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

Review on Improvement,Modeling,and Application of Ionic Polymer Metal Composite Artificial Muscle

引用

Journal of Bionic Engineering 2022年第2期19卷 279-298页

作者： Qingsong He Guoxiao Yin David Vokoun Qi Shen Ji Lu xiaofang liu Xianrui Xu Min Yu Zhendong Dai Jiangsu Provincial Key Laboratory of Bionic Functional Materials Institute of Bio-Inspired Structure and Surface EngineeringCollege of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China Institute of Physics of the Academy of Sciences of the Czech Republic Prague 18221Czech Republic Active Materials and Smart Living Laboratory Department of Mechanical EngineeringUniversity of Nevada Las VegasLas Vegas 89154-4027USA

Recently,researchers have concentrated on studying ionic polymer metal composite(IPMC)artificial muscle,which has numerous advantages including a relatively large strain under low input voltage,flexibility,high response,low noise,light weight,and high driving energy density.This paper reports recent developments in IPMC artificial muscle,including improvement methods,modeling,and applications.Different types of IPMCs are described,along with various methods for overcoming some shortcomings,including improvement of Nafion matrix membranes,surface preparation of Nafion membranes,the choice of high-performing electrodes,and new electro-active polymers for enhancing the properties of IPMCs.IPMC models are also reviewed,providing theoretical guidance for studying the performance and applications of IPMCs.Successful applications such as bio-inspired robots,opto-mechatronic systems,and medical engineering are discussed.

关键词： Ionic polymer metal composite Artificial muscle Improvement Model Bio-inspired application

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

Attaining enhanced thermoelectric performance in p-type(SnSe)1–x(SnS2)x produced via sintering their solution-synthesized micro/nanostructures

引用

Journal of Materials Science & Technology 2022年第25期120卷 205-213页

作者： xiaofang liu Hengyang Wang Bin Zhang Sikang Zheng Yao Chen Hong Zhang Xianhua Chen Guoyu Wang Xiaoyuan Zhou Guang Han College of Materials Science and Engineering Chongqing UniversityChongqing400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing400044China Analytical and Testing Center Chongqing UniversityChongqing401331China College of Physics Chongqing UniversityChongqing401331China Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing400714China

SnSe,possessing strong lattice anharmonicity and structural anisotropy,has attracted massive attention in thermoelectric conversion.Herein,we demonstrate that simultaneously optimized electrical and thermal transport properties are achieved in SnS_(2) -alloyed SnSe polycrystalline materials,which were fabricated via sintering the mixture of solution-synthesized SnSe microplates and SnS_(2) nanoplates.Resulting from the increased carrier concentration,p-type(SnSe)_(1–x)(SnS_(2))_(x)(x=0.5%,1%)samples obtain muchimproved power factor between 300 K and 373 K,e.g.0.72 mW m^(–1)K^(–2)at 300 K for(SnSe)0.99(SnS_(2) )0.01,which is enhanced by 53%compared to that of SnSe.Additionally,the existing point defects and planar defects effectively strengthen phonon scattering,thus reducing the lattice thermal conductivity,for example,0.47 W m^(–1) K^(–1) at 773 K for the x=0.02 sample.Eventually,a maximum zT of 0.80 at 823 K and an average zT of 0.52 over 300–823 K are obtained in the(SnSe)0.99(SnS_(2))0.01 sample,which are increased by 33%and 45%compared to those of SnSe,respectively.This study demonstrates a secondary phase alloying strategy to synergistically optimize the electrical and thermal properties of polycrystalline SnSe.

关键词： Thermoelectric SnSe SnS2 Solvothermal synthesis Lattice thermal conductivity

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

Inorganic microporous membranes for hydrogen separation:Challenges and solutions

引用

Nano Research Energy 2022年第2期1卷 51-62页

作者： Ahui Hao Xin Wan xiaofang liu Ronghai Yu Jianglan Shui School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Porous membrane separation is a competitive hydrogen purification technology due to the advantages of environmental friendliness,energy-saving,simple operation,and low cost.Benefiting from the booming development of materials science and chemical science,great progress has been made in H_(2) separation with porous membranes.This review focuses on the latest advances in the design and fabrication of H_(2) separation inorganic microporous membranes,with emphasis on the synthetic strategies to achieve structural integrity,continuity and stability.This review starts with a brief introduction to the membrane separation mechanisms,followed by an elaboration on the synthetic challenges and corresponding solutions of various high-performance inorganic microporous membranes based on zeolites,silica,carbon,and metal-organic frameworks(MOFs).At last,by highlighting the prospects of ultrathin two-dimensional(2D)porous membranes,we wish to shed some light on the further development of new materials and membranes for highly efficient hydrogen separation.

关键词： microporous membrane H_(2)separation zeolite membrane silica membrane carbon membrane metal-organic framework(MOF)membrane

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

Effects of nitrogen dioxide and its acid mist on reactive oxygen species production and antioxidant enzyme activity in Arabidopsis plants

引用

Journal of Environmental Sciences 2015年第8期27卷 93-99页

作者： xiaofang liu Fen Hou Guangke Li Nan Sang College of Environment and Resource Research Center of Environment and Health Shanxi University College of Environmental Science and Engineering Nankai University

Nitrogen dioxide（NO2） is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species（ROS） production and antioxidant enzyme activity in Arabidopsis thaliana（Col-0） exposed to 1.7, 4, 8.5, and 18.8 mg/m3NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll（Chl） content, and increased oxygen free radical（O2-）production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate（As A） and glutathione（GSH） contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage.

关键词： Nitrogen dioxide Nitric acid mist Arabidopsis thaliana Reactive oxygen species Antioxidant system

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

概率驱动的动态多目标多智能体协同调度进化优化

引用

计算机应用 2024年第5期44卷 1372-1377页

作者：刘晓芳张军南开大学人工智能学院天津300350

在多智能体系统中,协作任务往往动态变化,且存在多个冲突的优化目标,因此动态多目标多智能体协同调度问题已经成为亟须解决的关键问题之一。针对动态环境下多智能体协同调度需求,提出了概率驱动的动态预测策略,旨在有效利用历史环境概... 详细信息

在多智能体系统中,协作任务往往动态变化,且存在多个冲突的优化目标,因此动态多目标多智能体协同调度问题已经成为亟须解决的关键问题之一。针对动态环境下多智能体协同调度需求,提出了概率驱动的动态预测策略,旨在有效利用历史环境概率分布,预测决策解在新环境的概率分布,从而生成新的多智能体调度方案,实现调度算法在动态环境下的快速响应。具体来讲,设计了基于元素的概率分布表达,以表示解的构成元素在动态环境的适应性,并根据优化算法迭代最优解逐步更新概率分布以趋近实际分布;构建了基于融合的概率分布预测机制,考虑到环境变化的连续性和相关性,当环境变化时,通过融合历史概率分布预测新环境的概率分布,为新环境优化提供先验知识;提出了基于启发式的新解采样机制,结合概率分布和启发式信息,生成解方案以更新过时种群。将概率驱动的动态预测策略嵌入新型的多目标进化算法,获得概率驱动的动态多目标进化算法。在10个动态多目标多智能体协同调度问题实例上,实验结果表明,所提算法在解最优性和多样性上显著优于已有多目标进化算法,所提的概率驱动的动态预测策略能够提高多目标进化算法对动态环境的适应能力。

关键词：动态多目标优化粒子群优化进化计算多智能体协同调度概率驱动

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

Heterosis for water uptake by maize (Zea mays L.) roots under water deficit: responses at cellular, single-root and whole-root system levels

引用

Journal of Arid Land 2013年第2期5卷 255-265页

作者： xiaofang liu SuiQi ZHANG Lun SHAN State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Northwest A&F University Graduate University of Chinese Academy of Sciences

To examine the potential heterosis for water uptake by maize roots, the hydraulic properties of roots in the F1 hybrid （Hudan 4） were compared with those of its inbred parents （ 478 and Tian 4） at cellular, single-root and whole-root system levels under well-watered and water-deficit conditions. The cell hydraulic conductivity （Lpc） decreased under water deficit, but the Lpc of the F1 was higher than that of its inbred parents with or without stress from water deficit. Marked reductions in Lpc were observed following Hg2＋ treatment. The hydrostatic hydraulic conductivity of single roots （hydrostatic Lpsr） varied among genotypes under the two water treatments, with the highest in the F1 and the lowest in 478. Radial hydraulic conductivity （radial Lpsr） and axial hydraulic conductance （Lax） of the three genotypes varied similarly as Lpsr. The variations in hydraulic parameters were related to root anatomy. Radial Lpsr was negatively correlated with the ratio of cortex width to root diameter （R2=-0.77, P〈0.01）, whereas Lax was positively correlated with the diameter of the central xylem vessel （R2=0.75, P〈0.01） and the cross-sectional area of xylem vessels （R2=0.93, P〈0.01 ）. Hydraulic conductivity （Lpwr） and conductance （Lwr） of the whole-root system followed the same trend under the two water treatments, with the highest values in the F1. The results demonstrated that heterosis for water uptake by roots of the F1 occurred at cellular, single-root and whole-root system levels under well-watered and water-deficit conditions.

关键词： heterosis water uptake hydraulic conductivity water deficit maize

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

Stability of PGM-free fuel cell catalysts: Degradation mechanisms and mitigation strategies

引用

Progress in Natural Science:Materials International 2020年第6期30卷 721-731页

作者： Xin Wan xiaofang liu Jianglan Shui School of Materials Science and Engineering Beihang University

While Platinum group metals(PGM) free catalysts are promising alternatives to expensive Pt as the cathode catalyst in proton exchange membrane fuel cells, their rapid degradation must be addressed for the commercial feasibility. This review provides a historical survey of the possible degradation mechanisms of PGM-free catalysts. Decades of extensive studies confirm that carbon oxidation and demetalation are primarily responsible for the instability, whereas the mechanisms of protonation and micropore flooding are strongly criticized. Based on the mechanism understanding, the mitigation strategies for improving stability are discussed in detail. Finally,some directions to achieve high-performance and durable PGM-free catalysts are proposed.

关键词： Fuel cell Oxygen reduction PGM-Free catalysts Stability Mitigation strategy

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

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：