检索结果-南通市图书馆

Recent Advances in Asymmetric Structural composites for Excellent Electromagnetic Interference Shielding: A Review

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou Bai Xue lan Xie chang-Mei wu Qiang Zheng Department of Polymer Materials and Engineering College of Materials and Metallurgy Guizhou University National Engineering Research center for compounding and Modification of Polymer Materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University Department of Polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Microano functional filler Polymer composite Electromagnetic interference shielding

Bioinspired supramolecular macrocycle hybrid membranes with enhanced proton conductivity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第2期17卷 797-805页

作者： Pengfei Yang Linlin Xu Panagiotis Trogadas Marc-Olivier coppens Yang lan centre for Nature Inspired Engineering Department of Chemical EngineeringUniversity College LondonLondon WC1E 7JEUK

Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFcs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(cB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NIcE)*** carbonyl groups of cB[n]act as proton-conducting sites,while the host–guest interaction between cB[n]and water molecules offers extra protonconducting ***,the molecular size of cB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK ***,all hybrid membranes exhibit significantly enhanced proton ***,the SPEEK membrane incorporating 1 wt.%cB[8](cB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°c and 100%relative humidity(Rh),which is 228%greater than that of the pure SPEEK membrane under the same ***,hybrid membranes exhibit superior fuel cell *** cB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mw·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mw·cm^(−2))at 50°c and 100%*** findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.

关键词： supramolecular macrocycle proton conductivity cucurbit[n]uril proton exchange membrane fuel cell

Engineering punching shear strength of flat slabs predicted by nature-inspired metaheuristic optimized regression system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and civil Engineering 2024年第4期18卷 551-567页

作者： Dinh-Nhat TRUONG Van-lan TO Gia Toai TRUONG hyoun-Seung JANG Department of civil Engineering University of Architecture Ho Chi Minh CityHo Chi Minh City 700000Vietnam Faculty of civil Engineering and Technology Dong A UniversityDa Nang City 550000Vietnam School of Architecture Seoul National University of Science and TechnologySeoul 01811Republic of Korea

Reinforced concrete(Rc)flat slabs,a popular choice in construction due to their flexibility,are susceptible to sudden and brittle punching shear *** design methods often exhibit significant bias and *** estimation of punching shear strength in Rc flat slabs is crucial for effective concrete structure design and *** study introduces a novel computation method,the jellyfish-least square support vector machine(JS-LSSVR)hybrid model,to predict punching shear *** combining machine learning(LSSVR)with jellyfish swarm(JS)intelligence,this hybrid model ensures precise and reliable *** model’s development utilizes a real-world experimental data *** with seven established optimizers,including artificial bee colony(ABc),differential evolution(DE),genetic algorithm(GA),and others,as well as existing machine learning(ML)-based models and design codes,validates the superiority of the JS-LSSVR hybrid *** innovative approach significantly enhances prediction accuracy,providing valuable support for civil engineers in estimating Rc flat slab punching shear strength.

关键词： punching shear strength reinforced concrete flat slabs machine learning jellyfish search support vector machine

Mechanical Behavior and Failure Mechanism of an As-Extruded Mg-11wt%Y Alloy at Elevated Temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 969-981页

作者： lan Zhang Dao-Kui Xu Bao-Jie wang cui-lan Lu Shuo wang Xiang-Bo Xu Dong-Liang wang Xin Lv En-hou han School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Environmental and chemical Engineering Shenyang Ligong UniversityShenyang110159China Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Institute of corrosion Science and Technology Guangdong510070China

Through carrying out the high-temperature tensile experiments on an as-extruded Mg-11wt%Y alloy at 350℃,400℃,450℃,500℃and 550℃,the mechanical behavior and fracture mechanisms at elevated temperatures are investigated and *** results show that with the increase of temperature,the yield strength and ultimate tensile strength of the alloy increase at first and then decrease,while that the elongation ratio decreases firstly and then *** the sample being tested at 350℃,the values of yield strength,ultimate tensile strength and the elongation ratio are 188 MPa,266 MPa and 11%,*** 400℃,the yield strength and ultimate tensile strength reach the maximum values of,respectively,198 MPa and 277 MPa,but the elongation ratio is the lowest and its value is only 8%.when the applied temperature is increased to 550℃,the values of yield strength and ultimate tensile strength,respectively,decrease to 140 MPa and 192 MPa and the elongation ratio increases to 38%.Failure analysis demonstrates that the fracture surfaces of different samples are mainly composed of plastic dimples and exhibit the typical characteristic of ductile *** observation to the fracture side surfaces indicates that at the temperatures of 350℃and 400℃,microcracks mainly initiate in the interior of Mg_(24)Y_(5)*** the temperatures are 450℃,500℃and 550℃,the cracks preferentially initiate at the Mg_(24)Y_(5)/α-Mg interfaces.

关键词： Mg-Y alloy high-temperature tensile properties Fracture mechanism Failure analysis

Microwave Through wall Imaging via An Induced current Learning Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2024年第3期33卷 248-254页

作者： Pengjin lan Jianguo huang Tianyi Zhou Faculty of Electrical Engineering and computer Science Ningbo UniversityNingbo 315211China

In this paper,an induced current learning method(IcLM)for microwave through wall imaging(TwI),named as TwI-IcLM,is *** the inversion of induced current,the unknown object along with the enclosed walls are treated as a combination of ***,a non-iterative method called distorted-Born backpropagation(DB-BP)is utilized to generate the initial *** the training stage,several convolutional neural networks(cNNs)are cascaded to improve the estimated induced *** addition,a hybrid loss function consisting of the induced current error and the permittivity error is used to optimize the network ***,the relative permittivity images are conducted analytically using the predicted current based on *** the numerical and experimental TwI tests prove that,the proposed method can achieve better imaging accuracy compared to traditional distorted-Born iterative method(DBIM).

关键词： through wall imaging inverse scattering problem convolutional neural network(cNN)

Selective photosynthesis of Z-olefins through crystalline metal-organic cage-initiated expeditious cascade reactions

在线全文

学校读者我要写书评

暂无评论

carbon Energy 2024年第3期6卷 118-131页

作者： Jia-Ni Lu Yunze huang Yuan-Sheng Xia Long-Zhang Dong Lei Zhang Jing-Jing Liu lan-Gui Xie Jiang Liu Ya-Qian lan Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials ScienceJiangsu Collaborative Innovation Centre of Biomedical Functional MaterialsNanjing Normal UniversityNanjingChina School of chemistry South China Normal UniversityGuangzhouChina

The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical ***,flammable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial ***,we connect the photocatalytic hydrogen evolution reaction and the semihydrogenation reaction of alkynes in series and successfully realize the high selective production of Z-alkenes using low-cost,safe,and green water as the proton *** the cascade reaction,a series of isomorphic metal–organic cage catalysts(co_(x)Zn_(8−x)L_(6),x=0,3,4,5,and 8)are designed and synthesized to improve the yield of the photocatalytic hydrogen *** them,co_(5)Zn_(3)L_(6) shows the highest photocatalytic activity,with a h_(2) generation rate of 8.81 mmol g^(−1) h^(−1).Then,co_(5)Zn_(3)L_(6) is further applied in the above tandem reaction to efficiently reduce alkynes to Z-alkenes under ambient conditions,which can reach high conversion of>98%and high selectivity of>99%,and maintain original catalytic activity after multiple ***“one-pot”tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z-olefins under mild reaction conditions.

关键词： alkyne semi-hydrogenation hydrogen evolution reaction metal-organic cages photocatalysis Z-olefins

A Strong, Tough, and Self-healing Strengthening Thioctic Acid-based Elastomer for highly Reliable Flexible Strain Sensor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2024年第10期42卷 1610-1618页

作者： Xin-Yu chen Yu-Bing Fu Xue-Ling Yan lan Liu School of Materials Science and Engineering Key Lab of Guangdong Province for High Property and Functional Polymer Materials South China University ofTechnology

Elastomers with high strength and toughness, excellent self-healing properties, and biocompatibility have broad application prospects in wearable electronics and other fields, but preparing it remains a challenge. In this work, we propose a highly adaptable strategy by introducing the small molecule crosslinking agent of triethanolamine (TEA) to the poly(thioctic acid)(PTA) chains and preparing the PAx Ey elastomers using a simple synthesis step. This strategy stabilizes the PTA chains by constructing multiple non-covalent cross-linked dynamic networks, endowing materials with excellent strength and toughness (tensile strength of 288 kPa, toughness of 278.2 kJ/m3), admirable self-healing properties (self-healing efficiency of 121.6%within 7 h at 70°c), and good biocompatibility. The PAx Ey elastomers can also be combined with MwNTs to become flexible strain sensors, which can be used to monitor human joint movements with high sensitivity, repeatable responses, and stability.

关键词： Flexible strain sensor Ion clusters Multiple dynamic networks Self-healing strengthening Thioctic acid

wigner function of optical cumulant operator and its dissipation in thermo-entangled state representation

在线全文

学校读者我要写书评

暂无评论

chinese Physics B 2024年第6期33卷 205-210页

作者：张科李兰兰范洪义 School of Electronic Engineering Huainan Normal UniversityHuainan 232038China Department of Material Science and Engineering University of Science and Technology of ChinaHefei 230026China

To conveniently calculate the wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the wigner function, and its relation to weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.

关键词： wigner function optical cumulant operator dissipation evolution thermo-entangled state representation integration within ordered product of operators

high-entropy design boosts dielectric energy storage

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 4013-4015页

作者： Qiu-Ying Xia he Zhu Si lan Yang Ren herbert Gleiter Institute of Nanoscience School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Physics City University of Hong KongHong Kong999077China

Dielectric capacitors are vital for advanced electronic and electrical power systems due to their impressive power density and ***,a persistent challenge has been enhancing their energy densities while maintaining high *** in Science,a novel high-entropy design for relaxor ferroelectric materials has been proposed,promising significant improvements in both energy density and efficiency for multilayer dielectric ceramic *** the crucial role of high-entropy design in energy storage materials and devices,this highlight focuses on interpreting the progress and significance of this innovative work.

关键词： ceramic dielectric energy