检索结果-南通市图书馆

Huge Capacity Fiber-Optic Sensing Network Based on Ultra-Weak Draw Tower Gratings

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2016年第1期6卷 26-41页

作者： Minghong YANG Wei BAI Huiyong GUO Hongqiao wen haihu YU Desheng JIANG National Engineering Laboratory for Fiber Optic Sensing Technology Wuhan University of Technology Wuhan 430070 China

This paper reviews the work on huge capacity fiber-optic sensing network based on ultra-weak draw tower gratings developed at the National Engineering Laboratory for Fiber Optic Sensing Technology （NEL-FOST）, Wuhan University of Technology, China. A versatile drawing tower grating sensor network based on ultra-weak fiber Bragg gratings （FBGs） is firstly proposed and demonstrated. The sensing network is interrogated with time- and wavelength-division multiplexing method, which is very promising for the large-scale sensing network.

关键词： Ultra-weak FBG optical fiber sensors sensing network

Low temperature specific heat in BaFe_(1.9)Ni_(0.1)As_2 single crystals

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 China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1221-1224页

作者： ZENG Bin MU Gang LUO HuiQian wen haihu National Laboratory for Superconductivity Institute of PhysicsChinese Academy of SciencesBeijing 100190China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Low-temperature specific heat was measured on the BaFe1.9Ni0.1As2 single crystals with critical transition temperature Tc = 20.1 K.A clear specific heat jump with the value ΔC/T|Tc ≈ 23 mJ/mol K2 was *** addition,a roughly linear magnetic field dependence of the electronic specific heat coefficient Δγ(H) was found in the zero-temperature limit,suggesting that at least one Fermi pocket,probably the hole derivative one,was fully gapped with a small anisotropy in the present sample.A slight curvature of the curve Δγ(H) may suggest a complex gap structure(anisotropic gap or nodes) at other Fermi surfaces.

关键词： specific heat BaFe1.9Ni0.1As2 nodeless gap

Growth and transport properties of CaFeAsF_(1-x) single crystals

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2014年第4期57卷 632-636页

作者： TAO Jian LI Sheng ZHU XiYu YANG Huan wen haihu Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNanjing University

Using self-flux method,we have successfully grown the parent phase of the single crystals of *** X-ray di?raction indicates good ***-plane resistivity shows a bad metallic behavior with a sharp drop of resistivity at about T SDW=*** anomaly is associated with the possible spin density wave(SDW)*** near T SDW,the resistivity exhibits a cusp-like feature,which may be understood as the strong coupling effect between the electrons and the antiferromagnetic(AF)spin fluctuations.A reduction of fluorine or application of a high pressure will suppress the SDW feature and induce *** effect measurements reveal a positive Hall coefficient below T SDW indicating a dominant role of the hole-like charge carriers in the parent *** magnetoresistance has been observed below T SDW suggesting multiple conduction channels of the charge carriers.

关键词： CaFeAsF 1-x single crystal antiferromagnetic spin order multiple conduction channels

SUPERCONDUCTING FILMS PREPARED BY ELECTRON CYCLOTRON RESONANCE PLASMA IONS DEPOSITION

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1990年第10期7卷 473-476页

作者： wen haihu SHENG Yanya ZHANG Fengying SHI Yicai REN Zhaoxing CAO Xiaowen Institute of Plasma Physics Academia SinicaHefei 230031

An Y-Ba-Cu-O superconducting film with onset temperature Tc(onset)=91K and zero resistance temperature Tc(end)=81.4K has been obtained for the first time by wing electron cyclotron resonance(ECR)plasma ions deposition *** relationship between the composition of the film and the atmosphere as well as the distance between the target and substrate has also been given.

关键词： technique. film resonance

Visualization of the electronic phase separation in superconducting K_(x)Fe_(2−y)Se_(2)

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

Nano Research 2021年第3期14卷 823-828页

作者： Yujie Chen Juan Jiang Haifeng Yang Pavel Dudin Alexey Barinov Zhongkai Liu haihu wen Lexian Yang Yulin Chen State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing100084China Department of Physics Clarendon LaboratoryUniversity of OxfordParks RoadOxfordOX13PUUK Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCA94720USA School of Physical Science and Technology ShanghaiTech University and CAS-Shanghai Science Research CenterShanghai201210China L’Orme des Merisiers Synchrotron SOLEILSaint Aubin-BP 4891192Gif sur Yvette CedexFrance Elettra-Sincrotrone Trieste TriesteBasovizza34149Italy ShanghaiTech Laboratory for Topological Physics Shanghai200031China National Laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityNanjing210093China Frontier Science Center for Quantum Information Beijing100084China

Type-II iron-based superconductors(Fe-SCs),the alkali-metal-intercalated iron selenide A_(x)Fe_(2−y)Se_(2)(A=K,Tl,Rb,etc.)with a superconducting transition temperature of 32 K,exhibit unique properties such as high Néel temperature,Fe-vacancies ordering,antiferromagnetically ordered insulating state in the phase diagram,and mesoscopic phase separation in the superconducting *** particular,the electronic and structural phase separation in these systems has attracted intensive attention since it provides a platform to unveil the insulating parent phase of type-II Fe-SCs that mimics the Mott parent phase in *** this work,we use spatial-and angle-resolved photoemission spectroscopy to study the electronic structure of superconducting K_(x)Fe_(2−y)Se_(2).We observe clear electronic phase separation of K_(x)Fe_(2−y)Se_(2) into metallic islands and insulating matrix,showing different K and Fe *** the metallic islands show strongly dispersive bands near the Fermi level,the insulating phase shows an energy gap up to 700 meV and a nearly flat band around 700 meV below the Fermi energy,consistent with previous experimental and theoretical results on the superconducting K_(1−x)Fe_(2)Se_(2)(122 phase)and Fe-vacancy ordered K_(0.8)Fe_(1.6)Se_(2)(245 phase),*** results not only provide important insights into the mysterious composition of phase-separated superconducting and insulating phases of K_(x)Fe_(2−y)Se_(2),but also present their intrinsic electronic structures,which will shed light on the comprehension of the unique physics in type-II Fe-SCs.

关键词： spatial-and angle-resolved photoemission spectroscopy(µ-ARPES) iron-based superconductors phase separation electronic structure

Strong coupling superconductivity and prominent superconducting fluctuations in the new superconductor Bi_4O_4S_3

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 China(Physics,Mechanics & Astronomy) 2013年第11期56卷 2019-2025页

作者： LI Sheng YANG Huan FANG DeLong WANG ZhenYu TAO Jian DING XiaXin wen haihu Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNanjing University National Laboratory for Superconductivity Institute of Physics and National Laboratory for Condensed Matter PhysicsChinese Academy of Sciences

Electric transport and scanning tunneling spectrum(STS)have been investigated on polycrystalline samples of the new superconductor Bi4O4S3.A weak insulating behavior in the resistive curve has been induced in the normal state when the superconductivity is suppressed by applying a magnetic ***,a kink appears on the temperature dependence of resistivity near 4 K at all high magnetic fields above 1 T when the bulk superconductivity is completely *** kink associated with the upper critical field as well as the wide range of excess conductance at low fields and high temperatures is explained as the possible evidence of strong superconducting *** the tunneling spectra,a superconducting gap of about 3 meV is frequently observed yielding a ratio of 2Δ/kB TC^*** value is much larger than the one predicted by the BCS theory in the weak coupling regime(2Δ/kB TC^3.53),which suggests the strong coupling superconductivity in the present ***,the gapped feature persists on the spectra until 14 K in the STS measurement,which suggests a prominent fluctuation region of *** a superconducting fluctuation can survive at very high magnetic fields,which are far beyond the critical fields for bulk superconductivity as inferred both from electric transport and tunneling measurements.

关键词： BiS2-based superconductor strong coupling superconductivity superconducting fluctuation

Low temperature specific heat of 12442-type KCa2Fe4As4F2 single crystals

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 99-104页

作者： Teng Wang JiaNan Chu JiaXin Feng LingLing Wang XuGuang Xu Wei Li haihu wen XiaoSong Liu Gang Mu State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China CAS Center for Excellence in Superconducting Electronics(CENSE) Shanghai 200050China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNanjing UniversityNanjing 210093China

Low-temperature specific heat(SH)is measured for the 12442-type KCa2Fe4As4F2 single crystal under different magnetic fields.A clear SH jump with the height of?C/T|Tc=130 mJ mol-1 K-2 is observed at the superconducting transition temperature *** is found that the electronic SH coefficient?γ(H)quickly increases when the field is in the low-field region below 3T and then considerably slows down the increase with a further increase in the field,which indicates a rather strong anisotropy or multi-gap feature with a small minimum in the superconducting gap(s).The temperature-dependent SH data indicate the presence of the T2 term,which supplies further information and supports the picture with a line-nodal gap ***,the onset point of the SH transition remains almost unchanged under the field as high as 9 T,which is similar to that observed in cuprates,and places this system in the middle between the BCS limit and the Bose-Einstein condensation.

关键词： specific heat gap structure KCa2Fe4As4F2

Structural and transport properties of Sr_2VO_(3-δ)FeAs superconductors with different oxygen deficiencies

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1202-1206页

作者： HAN Fei ZHU XiYu MU Gang CHENG Peng SHEN Bing ZENG Bin wen haihu National Laboratory for Superconductivity Institute of Physics and Beijing National Laboratory for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100190China

Sr2VO3-δFeAs superconductors with different oxygen deficiencies have been successfully *** is found that the superconducting transition temperature drops down monotonically with the increase of nominal oxygen *** diminishing of superconductivity is accompanied by the enhancement of residual resistivity,indicating an anomalous scattering effect induced by the oxygen *** highest superconducting transition temperature at about 36 K is achieved near the stoichiometrical sample *** Hall effect measurements reveal that the density of charge carriers(electron-like here) varies qualitatively with the increase of nominal oxygen *** measurements show that the superconducting transition changes from one-step-like shape at low fields to two-step-like one at high fields,indicating an enhanced vortex motion due to the high anisotropy.

关键词： iron-based superconductor oxygen deficiency transport properties high anisotropy

在线全文

学校读者我要写书评

暂无评论

新型高温超导材料研究进展

材料研究学报 2015年第4期29卷 241-254页

作者：闻海虎南京大学物理学院固体微结构国家重点实验室人工微结构科学与技术协同创新中心超导物理和材料研究中心南京210093

超导自从1911年被发现以来,研究对象经历了从简单金属,到合金,再到复杂化合物,超导转变温度也逐渐提升,目前已经提升到164 K(高压测量)。在研究新型高温超导材料的过程中,对超导物理的理解也不断更新。在超导领域取得巨大成功的Bardeen-... 详细信息

超导自从1911年被发现以来,研究对象经历了从简单金属,到合金,再到复杂化合物,超导转变温度也逐渐提升,目前已经提升到164 K(高压测量)。在研究新型高温超导材料的过程中,对超导物理的理解也不断更新。在超导领域取得巨大成功的Bardeen-Cooper-Schrieffer理论,似乎在一些新型的非常规超导体中不再适用,因此非常规超导机理的理解也面临重大突破。本文将简单介绍目前发现的三类高温超导体:铜氧化物超导体,铁基超导体和二硼化镁超导体。结合目前研究中的一些经验,对如何寻找新型超导体提出展望。

关键词：综述超导体超导电性库柏对探索新型超导体