检索结果-内蒙古大学图书馆

New FeNiCrMo(P, C, B) high-entropy bulk metallic glasses with unusual thermal stability and corrosion resistance

Journal of materials Science & technology 2020年第8期36卷 32-39页

作者： Yanhui Li Siwen Wang Xuewei Wang Meiling Yin Wei Zhang Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China

New Fe(20–35) Ni(20) Cr(20–30) Mo(5–15)(P(0.6) C(0.2) B(0.2))(20) bulk metallic glasses with excellent thermal stability,strength, and corrosion resistance have been developed through the high-entropy alloy design *** high-entropy bulk metallic glasses(HE-BMGs) possess larger supercooled liquid regions of ~69 K,higher crystallization onset temperatures of ~852 K, larger undercoolings of ~109 K, and more sluggish crystallization process upon heating than the conventional metallic glass benefited from the high mixing entropy effect. The HE-BMGs also exhibit ultrahigh strength of ~3.4 GPa, Vickers hardness of ~1107,and superior corrosion resistance in acids and Na Cl solutions by formation of highly stable Cr-and Moenriched passive films. The new metal-metalloid HE-BMG system and exceptional properties give the alloys good promise for both scientific and engineering applications.

关键词： High-entropy bulk metallic glasses Thermal stability Crystallization Corrosion resistance FeNiCrMo(P,C,B)alloys

来源：评论

学校读者我要写书评

暂无评论

Influence of a Static Magnetic Field on Laser Induced Tungsten Plasma in Air

引用

Plasma Science and technology 2016年第4期18卷 364-369页

作者：吴鼎刘平孙立影海然丁洪斌 Key Laboratory of Materials Modification by Laser Ion and Electron BeamsChinese Ministry of EducationSchool of Physics and Optical EngineeringDalian University of Technology

In this work,laser induced tungsten plasma has been investigated in the absence and presence of 0.6 T static transverse magnetic field at atmospheric pressure in *** spectroscopic characterization of laser induced tungsten plasma was experimentally studied using space-resolved emission *** atomic emission lines of tungsten showed a significant enhancement in the presence of a magnetic field,while the ionic emission lines of tungsten presented little *** variation of the optical emission lines of tungsten indicated that the atomic emission time in the presence of a magnetic field was longer than that in the absence of a magnetic field,while no significant changes occurred for the ionic emission *** spatial resolution of optical emission lines of tungsten demonstrated that the spatial distribution of atoms and ions were *** influence of a magnetic field on the spatial distribution of atoms was remarkable,whereas the spatial distribution of ions was little influenced by the magnetic *** different behaviors between ions and atoms with and without magnetic field in air were related to the various atomic processes especially the electrons and ions recombination process during the plasma expansion and cooling process.

关键词： laser-induced breakdown spectroscopy magnetic field tungsten plasma spatial evolution

来源：评论

学校读者我要写书评

暂无评论

Analysis of anomalous transport based on radial fractional diffusion equation

引用

Plasma Science and technology 2022年第4期24卷 106-113页

作者： Kaibang WU Lai WEI Zhengxiong WANG Key Laboratory of Materials Modification by Beams of the Ministry of Education School of PhysicsDalian University of TechnologyDalian 116024People's Republic of China

Anomalous transport in magnetically confined plasmas is investigated by radial fractional transport *** is shown that for fractional transport models,hollow density profiles are formed and uphill transports can be observed regardless of whether the fractional diffusion coefficients(FDCs)are radially dependent or *** a radially dependent FDC

关键词： anomalous transport hollow profile non-locality fractional diffusion equation

来源：评论

学校读者我要写书评

暂无评论

Delta distribution of electronegative plasma predicted by reformed“spring oscillator”dynamic equation with dispersing force

引用

Chinese Physics B 2021年第5期30卷 484-491页

作者： Shu-Xia Zhao Jing-Ze Li Key Laboratory of Materials Modification by laser Ion and Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

In our relevant paper[Zhao S X(2021)***.B 30055201],a delta distribution of negative ions is given by fluid simulation and preliminarily explained by decomposed anions transport *** the present work,first,the intrinsic connection between the electropositive plasma transport equation and spring oscillator dynamic equation is *** by this similarity,reformed“spring oscillator”equation with dispersing instead of restoring force that gives quasi-delta solution is devised according to the math embodied in the anion equation,which is of potential significance to the disciplines of atomic physics and astronomy as *** solving the“diffusion confusion”the physics that determines the delta profile within the continuity equation is explored on the basis that recombination loss source term plays the role of drift flux,which is applicable for fluid model of low temperature plasma,but not the ordinary fluid ***,the math and physics revealed in this work predict that the ratio of recombination or attachment(for electrons)frequency versus the species diffusion coefficient is a very important parameter in determining the delta distribution,as it acts as the acceleration of object,according to the reformed oscillator *** this theory,the analogous delta profile of electrons density in the famous drift and ambi-polar diffusion heating mechanism of electronegative capacitively coupled plasma is interpreted.

关键词： delta distribution electronegative plasma revised spring oscillator dispersing force

来源：评论

学校读者我要写书评

暂无评论

Automatic emissive probe apparatus for accurate plasma and vacuum space potential measurements

引用

Plasma Science and technology 2018年第2期20卷 8-12页

作者：李建泉陆文琪徐军高飞王友年 Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Dalian University of Technology)Ministry of Education School of Physics Dalian University of Technology

We have developed an automatic emissive probe apparatus based on the improved inflection point method of the emissive probe for accurate measurements of both plasma potential and vacuum space *** apparatus consists of a computer controlled data acquisition card,a working circuit composed by a biasing unit and a heating unit,as well as an emissive *** the set parameters of the probe scanning bias,the probe heating current and the fitting range,the apparatus can automatically execute the improved inflection point method and give the measured *** validity of the automatic emissive probe apparatus is demonstrated in a test measurement of vacuum potential distribution between two parallel plates,showing an excellent accuracy of 0.1 *** potential was also measured,exhibiting high efficiency and convenient use of the apparatus for space potential measurements.

关键词： space potential emissive probe probe heating current LabVIEW

来源：评论

学校读者我要写书评

暂无评论

A brief review:effects of resonant magnetic perturbation on classical and neoclassical tearing modes in tokamaks

引用

Plasma Science and technology 2022年第3期24卷 1-13页

作者： Zhengxiong WANG Weikang TANG Lai WEI Key Laboratory of Materials Modification by Beams of the Ministry of Education School of PhysicsDalian University of TechnologyDalian 116024People's Republic of China

This paper reviews the effects of resonant magnetic perturbation(RMP)on classical tearing modes(TMs)and neoclassical tearing modes(NTMs)from the theory,experimental discovery and numerical results with a focus on four major aspects:(i)mode mitigation,where the TM/NTM is totally suppressed or partly mitigated by the use of RMP;(ii)mode penetration,which means a linearly stable TM/NTM triggered by the externally applied RMP;(iii)mode locking,namely an existing rotating magnetic island braked and finally stopped by the RMP;(iv)mode unlocking,as the name suggests,it is the reverse of the mode locking *** key mechanism and physical picture of above phenomena are revealed and summarized.

关键词： neoclassical tearing modes resonant magnetic perturbation mode locking

来源：评论

学校读者我要写书评

暂无评论

Diagnostics of First Wall materials in a Magnetically Confined Fusion Device by Polarization-Resolved Laser-Induced Breakdown Spectroscopy

引用

Plasma Science and technology 2014年第2期16卷 149-154页

作者：赵栋烨纳扎海然吴鼎丁洪斌 School of Physics and Optical Engineering Key Laboratory of Materials Modification by LaserIon and Electron BeamsChinese Ministry of EducationDalian University of Technology

Laser-induced breakdown spectroscopy （LIBS） is a powerful analytical tool for real- time diagnostics and detection of multiple elements deposited at the first wall of magnetically confined plasma ft^sion devices. Recently, we have tested LIBS in our laboratory for application to in situ real-time diagnostics in the fusion device EAST. In this study, we applied polarization- resolved LIBS （PR-LIBS） to reduce the background continuum and enhance the resolution and sensitivity of LIBS. We used aluminium （A1）（as a substitute for Be） and the first wall materials tungsten （W） and molybdenum （Mo） to investigate polarized continuum emission and signal-to- background ratio （SBR）. A Nd：YAG laser with first, second and third harmonics was used to produce plasma. The effects of the laser polarization plane, environmental pressure and polarizer detection angle were investigated. The spectra obtained without using a polarizer （i.e. LIBS） were compared with those obtained with a polarizer （PR-LIBS）. Distribution of emission spectral intensity was observed to follow Malus＇ law with respect to variation in the angle of detection of the polarizer. The spectra obtained by PR-LIBS had a higher SBR and greater stability than those obtained by LIBS, thereby enhancing the reliability of LIBS for quantitative analyses. A comparison of A1, Mo and W showed that W exhibited a higher continuum with stronger polarization than the low-Z elements.

关键词： LIBS PR-LIBS EAST first wall laser-produced plasma

来源：评论

学校读者我要写书评

暂无评论

Electron Acceleration During the Mode Transition from Laser Wakefield to Plasma Wakefield Acceleration with a Dense-Plasma Wall

引用

Plasma Science and technology 2013年第9期15卷 841-844页

作者：刘明萍刘三秋何俊刘杰 College of Information Engineering Nanchang University Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education Beijing Normal University Department of Physics Nanchang University Institute of Applied Physics and Computational Mathematics

The wake bubble expansion and contraction by adding a dense-plasma wall in the background plasma during the mode transition from laser wakefield to plasma wakefield accel- eration is investigated by particle-in-cell simulations. The electrons are injected continuously into the cavity until the lateral bubble size equals the inner diameter of the wall. The injected electron bunch from the laser wakefield acceleration （LWFA） scheme is quasi phase-stably accel- erated forward because of the longitudinal contraction of the bubble. After the laser pulse is depleted completely, the electron bunch generated from the LWFA scheme drives a plasma wake- field. The electrons remaining in the channel are trapped and accelerated by the plasma wakefield. Ultimately, two energetic electron bunches with a narrow energy spread and low emittance are obtained.

关键词： quasi phase-stable acceleration monoenergetic electron bunch dense-plasmawall

来源：评论

学校读者我要写书评

暂无评论

Measurement of electronegativity during the E to H mode transition in a radio frequency inductively coupled Ar/O2 plasma

引用

Chinese Physics B 2021年第3期30卷 371-377页

作者： Peng-Cheng Du Fei Gao Xiao-Kun Wang Yong-Xin Liu You-Nian Wang Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

This paper presents the evolution of the electronegativity with the applied power during the E to H mode transition in a radio frequency(rf)inductively coupled plasma(ICP)in a mixture of Ar and *** densities of the negative ion and the electron,as well as their ratio,i.e.,the electronegativity,are measured as a function of the applied power by laser photo-detachment combined with a microwave resonance probe,under different pressures and O2 ***,the optical emission intensities at Ar 750.4 nm and O 844.6 nm are monitored via a *** was found that by increasing the applied power,the electron density and the optical emission intensity show a similar trench,i.e.,they increase abruptly at a threshold power,suggesting that the E to H mode transition *** the increase of the pressure,the negative ion density presents opposite trends in the E-mode and the H-mode,which is related to the difference of the electron density and energy for the two *** emission intensities of Ar 750.4 nm and O 844.6 nm monotonously decrease with increasing the pressure or the O2 content,indicating that the density of high-energy electrons,which can excite atoms,is monotonically *** leads to an increase of the negative ion density in the H-mode with increasing the ***,as the applied power is increased,the electronegativity shows an abrupt drop during the E-to H-mode transition.

关键词： electronegativity E to H mode transition radio frequency inductively coupled plasma

来源：评论

学校读者我要写书评

暂无评论

Structure and Tribological Properties of CrTiAlN Coatings Deposited by Multi-Arc Ion Plating

引用

Plasma Science and technology 2011年第1期13卷 55-60页

作者：田灿鑫杨兵何俊王红军王泽松王广甫付德君 Accelerator Laboratory and Key Laboratory of Artificial Materials and Microstructures of Ministry of Education Wuhan University Key Laboratory of Beam Technology and Material Modication of Ministry of Education Beijing Normal University School of Power & Mechanical Engineering Wuhan University

CrTiAIN coatings were prepared by using a home-made industrial scale multi-arc ion plating system. The coatings were found to be composites of face-center-cubic CrN and TiN. The surface roughness, microhardness, and tribological properties of the films were significantly affected by the nitrogen pressure and dc-pulsed bias voltage applied to the substrate. The CrTiA1N coatings with the smoothest surfaces were obtained at optimum conditions of nitrogen pressure of 5.0 Pa and bias voltage of -200 V. The samples were found to exhibit a hardness of 2900 HV0.05 with an average friction coefficient of 0.16 and wear rate of 1.5× 10^-16 m^3/N.m against cemented carbide.

关键词： multi-arc ion plating CrTiAIN microhardness surface morphology friction coellicient wear rate

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：