检索结果-南通市图书馆

Design and implementation of the monochromator shielding for the cold neutron spectrometers XINGZHI and BOYA

Chinese Physics B 2024年第5期33卷 96-102页

作者：汪晋辰刘娟娟徐大业 Florian Grünauer 郝丽杰刘蕴韬张红霞程鹏鲍威 laboratory for neutron scattering and Beijing Key laboratory of Optoelectronic Functional Materials and MicroNano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China Physics Consulting Zorneding 85604Germany China Institute of Atomic Energy Beijing 102413China Department of Physics City University of Hong KongKowloon 999077China center for neutron scattering City University of Hong KongKowloon 999077China

An innovative monochromator shielding is designed and implemented for the cold neutron spectrometers XINGZHI and BOYA operated by Renmin University of China at China Advanced Research *** Monte Carlo simulations and careful mechanical designs,a shielding configuration has been successfully developed to satisfy safety requirements of below 3μSv/h dose rate at its exterior,meanwhile fulfilling space,floor load and nonmagnetic *** materials are utilized to form the sandwich-type shielding walls:the inner layer of boron carbide rubber,the middle layer of steel-encased lead and the outer layer of borated ***-shaped liftable shielding blocks are incorporated to facilitate a continuous adjustment of the neutron energy while preventing radiation *** work has demonstrated that by utilizing composite shielding materials,along with the sandwich structure and liftable shielding blocks,a compact and lightweight shielding solution can be *** enables the realization of advanced neutron scattering instruments that provide expanded space of measurement,larger energy and momentum coverage,and higher flux on the *** shielding represents the first of its kind in neutron scattering instruments in *** its successful operation,it has been subsequently employed by other neutron instruments across the country.

关键词： neutron scattering cold neutron spectrometer monochromator shielding sandwich shielding structure

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

Angular and planar transport properties of antiferromagnetic V5S8

引用

Chinese Physics B 2024年第2期33卷 83-88页

作者：吴晓凯王彬吴德桐陈博文弭孟娟王以林沈冰 center for neutron Science and Technology and School of Physics Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devicesand Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-Sen University School of Integrated Circuits Shandong Technology Center of Nanodevices and Integration State Key Laboratory of Crystal MaterialsShandong University

Systemically angular and planar transport investigations are performed in layered antiferromagnetic(AF) V5S8. In this AF system, obvious anomalous Hall effect(AHE) is observed with a large Hall angle of 0.1 compared to that in ferromagnetic(FM) system. It can persist to the temperatures above AF transition and exhibit strong angular field *** phase diagram reveals various magnetic states by rotating the applied field. By analyzing the anisotropic transport behavior, magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing line. The observed prominent planar Hall effect and anisotropic magnetoresisitivity exhibit two-fold systematical angular dependent oscillations. These behaviors are attributed to the scattering from spin–orbital coupling instead of nontrivial topological origin. Our results reveal anisotropic interactions of magnetism and electron in V5S8, suggesting potential opportunities for the AF spintronic sensor and devices.

关键词： antiferromagnetism planar Hall effect magnetic and topological properties

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

Anomalous thermal expansion and enhanced magnetocaloric effect in<001>-textured Mn_(x)Fe_(5-x)Si_(3) alloys

引用

Rare Metals 2024年第5期43卷 2263-2274页

作者： Yong Gong Xue-Fei Miao Tapas Samanta Chris Taake Jun Liu Feng-Jiao Qian Yan-Yan Shao Yu-Jing Zhang Qing-Yong Ren Luana Caron Feng Xu MIIT Key laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Department of Physics Bielefeld University33501BielefeldGermany College of Physics Nanjing University of Aeronautics and AstronauticsNanjing210016China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Spallation neutron Source Science center Dongguan523803China Guangdong-Hong Kong-Macao Joint laboratory for neutron scattering Science and Technology Dongguan523803China Department of Physics Bielefeld University33501BielefeldGermany Helmholtz-Zentrum Berlin für Materialien und Energie12489BerlinGermany

The development of zero and negative therma expansion(i.e.,ZTE and NTE)materials is of crucial importance to the control of undesirable thermal expansion for high-precision *** the present work,ZTE and NTE were obtained in directionally-solidified Mn_(x)Fe_(5-x)Si_(3)alloys with a strongtexture,in striking contrast to positive thermal expansion in their isotropic counterparts Magnetometry and in-situ X-ray diffraction(XRD)measurements were performed to uncover the origin of the anomalous thermal *** measurements indicate a strong easy-plane magnetocrystalline anisotropy in the textured samples,where the magnetic moments are aligned within the ab plane of the hexagonal structure Temperature-dependent XRD on the x=1 sample reveals a ZTE character in the ab plane that is coupled to a ferromagnetic *** a result,the macroscopic ZTE(~0.22×10^(-6)K^(-1))in the x=1 sample can be attributed to the microscopic magneto volume effect within the ab plane,which is realized by the introduction of the-textured ***,the competition between antiferromagnetic and ferromagnetic exchange coupling leads to NTE in textured x=1.5 and 2 ***,textured x=1 sample displays enhanced magnetocaloric properties as compared to the conventional counterparts with randomly-oriented *** this work demonstrates a new strategy toward the exploration of anomalous thermal expansion properties as well as the enhancement of magnetocaloric properties for materials with a strong magnetocrystalline anisotropy.

关键词： MnFeySis Magnetocaloric effect Magnetic phase transition Negative thermal expansion

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

Enhanced thermoelectric properties of topological crystalline insulator PbSnTe nanowires grown by vapor transport

引用

Nano Research 2016年第3期9卷 820-830页

作者： Enzhi Xu Zhen Li Jaime Aviles Acosta Nan Li Brian Swartzentruber ShiJian Zheng ,Nikolai Sinitsyn Han Htoon Jian Wang Shixiong Zhang Department of Physics Indiana University Bloomington Indiana 47405 USA center for Integrated Nanotechnologies Materials Physics and Applications Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA center for Integrated Nanotechnologies Sandia National Laboratories Albuquerque New Mexico 87185 USA Theoretical Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA MST-8 Los Alamos National Laboratory Los Alamos New Mexico 87545 USA

Bulk PbTe and alloy compounds thereof are well-known thermoelectric materials for electric power generation. Among these alloys, PbSnTe hosts unique topological surface states that may have improved thermoelectric properties. Here we report on the vapor-transport growth and thermoelectric study of high-quality single-crystalline PbTe and PbSnTe nanowires. The nanowires were grown along the 〈001〉 direction with dominant {100} facets; the chemical compositions of the wires depend strongly on the substrate position in the growth reactor. We measured the thermopower and electrical and thermal conductivities of individual nanowires to determine the thermoelectric figure of merit ZT. Compared to bulk samples, the PbSnTe nanowires showed both improved thermopower and suppressed thermal conductivity, enhancing the ZTs to -0.018 and N0.035 at room temperature. The enhanced thermopower may result from the unique topological surface states; the suppression of thermal conductivity may relate to increased phonon-surface scattering. Compared to PbTe nanowires, the PbSnTe wires have lower thermopower but significantly higher electrical conductivities. This study highlights nanostructuring in combination with alloying as an important approach to enhancing the figure of merit ZT of thermoelectric materials.

关键词： PbSnTe thermoelectrics topological crystallineinsulator nanowire

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

neutron Diffraction Study of Low-Cycle Fatigue Behavior in an Austenitic–Ferritic Stainless Steel

引用

Acta Metallurgica Sinica(English Letters) 2015年第10期28卷 1247-1256页

作者： Ming-Wei Zhu Nan Jia Feng Shi Bjorn Clausen School of Materials Science and Engineering Shenyang Aerospace University Key laboratory for Anisotropy and Texture of Materials(ATM) Northeastern University School of Science Northeastern University los alamos national laboratory Los Alamos Neutron Science Center

By performing in situ neutron diffraction experiments on an austenitic-ferritic stainless steel subjected to lowcycle fatigue loading, the deformation heterogeneity of the material at microscopic level has been revealed. Based on the in situ neutron diffraction data collected from a single specimen together with the mechanical properties learned from the ex situ micro-hardness, a correlation has been found. The performance versus diffraction-profile correlation agrees with the cyclic-deformation-induced dislocation evolution characterized by ex situ TEM observation. Moreover, based on the refined neutron diffraction-profile data, evident strain anisotropy is found in the austenite. The high anisotropy in this phase is induced by the increase in dislocation density and hence contributes to the hardening of the steel at the first 10 *** 10 fatigue cycles, the annihilation and the rearrangement of the dislocations in both austenitic and ferritic phases softens the plastically deformed specimen. The study suggests that the evolution of strain anisotropy among the differently oriented grains and micro-strain induced by lattice distortion in the respective phases mostly affect the cyclic-deformationinduced mechanical behavior of the steel at different stages of fatigue cycles. The stress discrepancy between phases is not the dominant mechanism for the deformation of the steel.

关键词： Duplex steel neutron diffraction Fatigue Plastic deformation Microstructure

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

Topological Confinement in Reversibly Interlocked Polymer Networks

引用

Chinese Journal of Polymer Science 2024年第2期42卷 133-140,I0004页

作者： Wan-Ting Dai Zhen-Hua Xie Yu-Bin Ke Yang You Min-Zhi Rong Ming-Qiu Zhang Key laboratory for Polymeric Composite and Functional Materials of Ministry of Education GD HPPC LabIGCMESchool of ChemistrySun Yat-sen UniversityGuangzhou510275China Spallation neutron Source Science center China Spallation Neutron SourceDongguan523803China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China College of Materials and Metallurgy Guizhou UniversityGuiyang550025China

Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.

关键词： Reversibly interlocked polymer networks Small angle X-ray scattering Small-angle neutron scattering Topological confinement

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

Angular and planar transport properties of antiferromagnetic V_(5)S_(8)

引用

Chinese Physics B 2024年第2期33卷 66-71页

作者：吴晓凯王彬吴德桐陈博文弭孟娟王以林沈冰 center for neutron Science and Technology and School of Physics Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devicesand Key Laboratory of Optoelectronic Materials and TechnologiesSun Yat-Sen UniversityGuangzhou 510275China School of Integrated Circuits Shandong Technology Center of Nanodevices and IntegrationState Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China

Systemically angular and planar transport investigations are performed in layered antiferromagnetic(AF)V_(5)S_(8).In this AF system,obvious anomalous Hall effect(AHE)is observed with a large Hall angle of 0.1 compared to that in ferromagnetic(FM)*** can persist to the temperatures above AF transition and exhibit strong angular field *** phase diagram reveals various magnetic states by rotating the applied *** analyzing the anisotropic transport behavior,magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing *** observed prominent planar Hall effect and anisotropic magnetoresisitivity exhibit two-fold systematical angular dependent *** behaviors are attributed to the scattering from spin–orbital coupling instead of nontrivial topological *** results reveal anisotropic interactions of magnetism and electron in V5S8,suggesting potential opportunities for the AF spintronic sensor and devices.

关键词： antiferromagnetism planar Hall effect magnetic and topological properties

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

Performance optimization of the neutron-sensitive image intensifier used in neutron imaging

引用

Chinese Physics B 2024年第8期33卷 380-387页

作者：谭金昊宋玉收周健荣杨文钦蒋兴奋刘杰张超月周晓娟夏远光刘术林闫保军刘辉王松林赵豫斌庄建孙志嘉陈元柏 Harbin Engineering University Harbin 150000China Spallation neutron Source Science center Dongguan 523803China State Key laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key laboratory of China Building Materials Industry for Special Photoelectric Materials Institute of Special Glass Fiber and Optoelectronic Functional MaterialsChina Building Materials AcademyBeijing 100024China

As a non-destructive testing technology,neutron imaging plays an important role in various fields,including material science,nuclear engineering,and fundamental *** imaging detector with a neutron-sensitive image intensifier has been developed and demonstrated to achieve good spatial resolution and timing ***,the influence of the working voltage on the performance of the neutron-sensitive imaging intensifier has not been *** optimize the performance of the neutron-sensitive image intensifier at different voltages,experiments have been performed at the China Spallation neutron Source(CSNS)neutron *** change in the light yield and imaging quality with different voltages has been *** is shown that the image quality benefits from the high gain of the microchannel plate(MCP)and the high accelerating electric field between the MCP and the *** the accelerating electric field is more effective than increasing the gain of MCPs for the improvement of the imaging *** the total gain of the MCP stack can be realized more effectively by improving the gain of the standard MCP than that of the n *** results offer a development direction for image intensifiers in the future.

关键词： neutron detector neutron imaging microchannel plate image intensifier

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

Pass/Fail Criterion for a Simple Radiation

引用

Modern Instrumentation 2012年第3期1卷 27-33页

作者： Tom Burr Avigdor Gavron neutron Science center Los Alamos National Laboratory Los Alamos USA Statistical Sciences Los Alamos National Laboratory Los Alamos USA

One of the simplest tests of a radiation portal monitor (RPM) is a series of n repeats (a vehicle drive-through) in which the ith repeat records a total number of counts Xi and alarms if Xi ≥ T where T is an alarm threshold. The RPM performance tests we consider use n repeats to estimate the probability p = P(Xi ≥ T). This paper addresses criterion A for testing RPMs, where criterion A is: for specified source strength, we must be at least 95% confident that p ≥ 0.5. To assess criterion A, we consider a distribution-free test and a test relying on assuming the counts Xi have approximately a Poisson distribution. Both test options require tolerance interval construction.

关键词： Poisson Distribution Radiation Portal Monitor Tolerance Interval

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

In-situ loading neutron-diffraction studies of a cobalt-based superalloy

引用

中国有色金属学会会刊：英文版 2006年第A2期16卷 144-148页

作者： M. L. BENSON P. K LIAW H. CHOO T. A. SALEH D. W. BROWN M. R. DAYMOND X. L. WANG A. D. STOICA E. C. OLIVER D. L. KLARSTROM Department of Materials Science and Engineering University of Tennessee Knoxville TN 37996 USA Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA los alamos neutron Science center Los Alamos National Laboratory Los Alamos NM 87545 USA Department of Mechanical and Materials Engineering Queen＇s University Kingston ON K7L3N6 Canada Spallation neutron Source Oak Ridge National Laboratory Oak Ridge TN 37831 USA ISIS Pulsed neutron and Muon Source Rutherford-Appleton Laboratory Chilton Didcot OX 11 0QX UK Haynes International Inc Kokomo IN 46904 USA

ULTIMET® alloy is a cobalt-based superalloy that undergoes a deformation-induced phase transformation from a face-centered-cubic (fcc) phase to a hexagonal-close-packed (hcp) phase. The transformation was studied during monotonic loading, stress-controlled high-cycle fatigue (HCF) and strain-controlled low-cycle fatigue (LCF). The HCF was performed at a maximum stress of σmax=840 MPa and a minimum stress of σmin=84 MPa, while the tensile experiment was terminated after reaching σmax=890 MPa. The LCF was performed at a maximum strain of σmax=1.25% and a minimum strain of σmin=-1.25%. The monotonic-loading experiment results reveal that the hcp phase forms after reaching the yield stress. During HCF, the hexagonal phase forms immediately upon the first fatigue cycle, with no further change in structure upon subsequent deformation. In contrast to HCF, the hcp phase forms gradually during LCF. In fact, fatigue cycle 12 is reached before the hcp phase is resolved by neutron diffraction. Diffraction patterns from subsequent fatigue cycles reveal that the hcp phase continues to accumulate as LCF progresses. These observations can be related to the input of mechanical energy during different loading modes.

关键词：钴基高温合金现场加载中子衍射 fcc hcp 相变

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：