检索结果-南通市图书馆

Discovery of tip induced unconventional superconductivity on Weyl semimetal

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

Science Bulletin 2017年第6期62卷 425-430页

作者： He Wang Huichao Wang Yuqin Chen Jiawei Luo Zhujun Yuan Jun Liu Yong Wang Shuang Jia Xiong-Jun Liu jian Wei Jian Wang International center for Quantum Materials School of Physics Peking University Beijing 100871 China Collaborative Innovation center of Quantum Matter Beijing China center of Electron microscopy State Key Laboratory of Silicon Materials School of Materials Sdence and Engineering Zhejiang University Hangzhou 310027 China

Weyl fermion is a massless Dirac fermion with definite chirality,which has been long pursued since *** it has not been observed as a fundamental particle in nature,Weyl fermion can be realized as low-energy excitation around Weyl point in Weyl semimetal,which possesses Weyl fermion cones in the bulk and nontrivial Fermi arc states on the surface. As a firstly discovered Weyl semimetal,Ta As crystal possesses 12 pairs of Weyl points in the momentum space,which are topologically protected against small perturbations. Here,we report for the first time the tip induced superconductivity on Ta As crystal by point contact spectroscopy. The zero bias conductance peak as well as a conductance plateau with double conductance peaks and sharp double dips are observed in the point contact spectra simultaneously,indicating unconventional superconductivity. Our further theoretical study suggests that the induced superconductivity may have nontrivial topology. The present work opens a new route in investigating the novel superconducting states based on Weyl materials.

关键词： Tip induced unconventional superconductivity Topological superconductivity Weyl semimetal TaAs Point contact spectroscopy

Probing conformational change of T7 RNA polymerase and DNA complex by solid-state nanopores

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第11期27卷 659-664页

作者： Xm Tong Rui Hu Xiaoqing Li Qing Zhao State Key Laboratory for Mesoscopic Physics and Electron microscopy Laboratory School of Physics Peking University Beijing 100871 China Collaborative Innovation center of Quantum Matter Beijing 100084 China

Proteins are crucial to most biological processes, such as enzymes, and in various catalytic processes a dynamic motion is required. The dynamics of protein are embodied as a conformational change, which is closely related to the flexibility of protein. Recently, nanopore sensors have become accepted as a low cost and high throughput method to study the features of proteins. In this article, we used a SiN nanopore device to study the flexibility of T7 RNA polymerase（RNAP） and its complex with DNA promoter. By calculating full-width at half-maximum（FWHM） of Gaussian fits to the blockade histograms, we found that T7 RNAP becomes more flexible after binding DNA promoter. Moreover, the distribution of fractional current blockade suggests that flexibility alters due to a breath-like change of the volume.

关键词： solid-state nanopore T7 RNA polymerase conformational change protein flexibility

Morphology controllable conjugated network polymers based on AIE-active building block for TNP detection

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第3期32卷 1037-1040页

作者： Shan Jiang Lingchen Meng Wenyue Ma Qingkai Qi Wei Zhang Bin Xu Leijing Liu Wenjing Tian State Key Laboratory of Supramolecular Structure and Materials Jilin UniversityChangchun 130012China Electron microscopy center Jilin UniversityChangchun 130012China

Luminescent conjugated network polymer is one of the most promising chemo-sensors owing to their good chemical/optical stability and multiple ***,three conjugated network polymers were prepared by using aggregation-induced emission active 1,1,2,2-tetrakis(4-formyl-(1,1’-biphenyl))-ethane(TFBE)unit as monomer and hydrazine as *** regulating the synthetical condition,the polyme ric network can form either unifo rm two-dimensional azine-linked nanosheets(ANS),conjugated microporous polymers(A-CMP)or covalent organic frameworks(A-COF).All of these polymers exhibited good stability and high fluorescence quantum efficiency with the quantum yield of6.31%for A-NS,5.26%for A-CMP,and 5.80%for A-COF,as well as fast and selective fluorescence quenching response to 2,4,6-trinitrophenol(TNP).And the best TNP sensing performance with the Stern-Volmer constants(K_(sv))values up to 8×10^(5)L/mol and a detection limit of 0.09μmol/L was obtained for *** study explores various strategies to construct conjugated polymers with different nanoarchitectures based on the same building block for sensitive detection of explosives.

关键词： Conjugated network polymers Aggregation-induced emission Morphology 2,4,6-Trinitrophenol Detection

Unusual relationship between impact toughness and grain size in a high-manganese steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第30期89卷 122-132页

作者： Pan Xie Shucheng Shen Cuilan Wu Jiehua Li Jianghua Chen center for High Resolution Electron microscopy College of Materials Science and EngineeringHunan UniversityChangsha410082China Institute of Casting Research Montanuniversität LeobenA-8700LeobenAustria

The high-manganese steels are important structural materials,owing to their excellent toughness at low ***,the microstructural causes for their unusual properties have not adequately been understood thus ***,we report a reversal relationship between impact toughness and grain size in a high-manganese steel and its unrevealed microscopic mechanisms,which result in an excellent low-temperature toughness of the *** investigations show that with increasing grain size the impact toughness of the steel can be improved drastically,especially at *** electron microscopy characterization reveals that the enhanced impact toughness of the coarse-grained steel is attributed to the twinning induced plasticity and transformation induced plasticity effects,which produce large quantities of deformation twins,ε_(hcp)-martensite andα'_(bcc)-***,in the fine-grained steels,the formation of deformation twins and martensite is significantly inhibited,leading to the decrease of impact *** characterizations also indicate thatε_(hcp)-martensite becomes more stable thanα'_(bcc)-martensite with decreasing temperature,resulting in characteristic microstructures in the coarse-grained samples after impact deformation at liquid nitrogen *** the coarse-grained samples under impact deformation at-80℃,ε_(hcp)-martensite transformation,α'_(bcc)-martensite transformation and deformation twinning all occur simultaneously,which greatly improves the toughness of the steel.

关键词： Toughness Grain size Twinning induced plasticity Transformations induced plasticity High-manganese steel

Optimal array alignment to deliver high performance in flexible conducting polymer-based thermoelectric devices

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第29期124卷 252-259页

作者： Shengduo Xu Meng Li Min Hong Lei Yang Qiang Sun Shuai Sun Wanyu Lyu Matthew Dargusch Jin Zou Zhi-Gang Chen School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQueensland4072Australia Centre for Future Materials University of Southern QueenslandSpringfield CentralQueensland4300Australia School of Materials Science&Engineering Sichuan UniversityChengdu 610064China Centre for microscopy and microanalysis The University of QueenslandBrisbaneQueensland4072Australia School of Chemistry and Physics Queensland University of TechnologyBrisbaneQueensland4000Australia

Flexible thermoelectric devices(F-TEDs)show great potentials to be applied in curved surface for power generation by harvesting low-grade energy from human body and other heat ***,their power generation efficiency is constrained by both unsatisfactory constituent materials performance and immature device ***,we used an optimal alignment of vertically-aligned poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)arrays to assemble a 2.7×3.2 cm^(2)F-TEDs,exhibiting a maximum power output of 10.5μ*** a high performance can be ascribed to the outstanding power factor of 198μW m^(-1)K^(-2)by the synergetic effect of both high charge mobility and optimal oxidation level and the optimized array alignment that maximizes the temperature difference utilization ratio across the TE ***,optimized leg distance of 6 mm and leg length of 12 mm are determined to realize a high temperature difference utilization ratio of over 95%and a record-high output power density of 1.21μW cm^(-2)under a temperature difference of 30 ***,reliable bending(1000 cycles)and stability(240 h)tests indicate the outstanding mechanical robustness and environmental stability of the developed *** study indicates our reasonable device design concept and facile material treatment techniques secure high-performance F-TEDs,serving as a reference for other flexible energy harvesting devices with wide practical applications.

关键词： Flexible thermoelectric device Performance optimization TE array alignment Optimized power density

Current Induced Non-Volatile Resistive Switching Effect in Silicon Devices with Large Magnetoresistance

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第7期31卷 156-159页

作者：王集敏章晓中朴红光罗昭初熊成悦 Key Laboratory of Advanced Materials (MOE) School of Materials Science and Engineering Tsinghua University Beijing 100084 National center for Electron microscopy (Beijing) Tsinghua University Beijing 100084

We develop a non-volatile resistive switching device in a Si-SiO2-Mg structure with an on/off ratio of about 4.5 at a certain transition voltage after being stimulated by a large current. It is observed that the resistance transition voltage Vt shifts reproducibly under a reversed large current. By applying a reading voltage in the range of Vt, non-volatile resistive switching phenomena with an endurance of more than 80 cycles are observed. Moreover, it is also found that the magnetic field could shift Vt to higher values, yielding a voltage dependent room-temperature magnetoresistance in the range of 10^3 % at 1 T. The multifunctional properties of the silicon device suggested by this work may be beneficial to the silicon based industry.

关键词： Magnetoresistance

Ag/graphene composite based on high-quality graphene with high electrical and mechanical properties

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

Progress in Natural Science:Materials International 2019年第4期29卷 384-389页

作者： Yanpeng Yang Yunjie Ping Youning Gong Zhongchi Wang Qiang Fu Chunxu Pan Suzhou Institute Wuhan University School of Physics and Technology MOE Key Laboratory of Artificial Micro-and Nano-structures Wuhan University center for Electron microscopy Wuhan University

A simple and effective process has been reported to prepare the silver(Ag)/graphene composite with excellent mechanical and electrical properties based on high-quality graphene(HQG).The HQG was fabricated via hot pressing of reduced graphene oxide(RGO) from chemical exfoliation,while the Ag/HQG composite was obtained by using spark plasma sintering(SPS) treatment under high temperature(1500℃) and moderate pressure(40 MPa).With low oxygen-containing functional groups and defect density,the HQG dispersed homogeneously in the composite after high-energy ball *** comparison to pure Ag,the as-prepared Ag/RGO composite exhibited a great enhancement of 11% electrical conductivity and 42% micro-hardness with an optimal RGO adding content(1 wt%).The Ag/HQG composite is expected to open up a new way for the novel Ag-based electrical contact materials,and further to broaden its applications in micro-electronics and switching power.

关键词： Graphene Silver Composite Electrical property Mechanical property

Bioelemental patterns in the cerebrospinal fluid as potential biomarkers for neurodegenerative disorders

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2018年第8期13卷 1356-1357页

作者： Fabian Maass Paul Lingor Department of Neurology University Medical Center GoettingenGermany cluster of excellence nanoscale microscopy and molecular Physiology of the Brain(CNMPB) GoettingenGermany

Neurodegenerative disorders like Parkinson＇s disease （PD） or atypi- cal Parkinsonian syndromes including the different synucleinopa- thies and tauopathies are an important burden for patients, rela- tives, care pro... 详细信息

关键词： PD Bioelemental patterns in the cerebrospinal fluid as potential biomarkers for neurodegenerative disorders

Synthesis of graphitic carbon nitride through pyrolysis of melamine and its electrocatalysis for oxygen reduction reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2013年第2期24卷 103-106页

作者： He-Sheng Zhai Lei Cao Xing-Hua Xia center for Scanning Electron microscopy Xiamen University State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical Engineering.Nanjing University

Received 2 December 2012 Received in revised form 26 December 2012 Accepted 31 December 2012 Available online 4 February 2013

关键词： Melamineg-C3N4Oxygen reduction reactionElectrocatalysis