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Research surveys of electrochemical sensors for in-situ determining hydrogen in steels

Gang YU , Xueyuan ZHANG , Yuanlong DU

材料科学技术(英文)

The principle, construction and application of two types of electrochemical sensors-amperometric and potentiometric are surveyed. Both types of sensors are very sensitive to changes in temperature. The accuracy of hydrogen measurement depends on both the precision of sensors developed and the reliable technique of installation and security of sensors. The two types of sensors have been used for in-situ determining hydrogen permeated in steels owing to a corrosive reaction, a hydrogen gas circumstance at elevated temperatures and high pressure or also a pretreatment process such as pickling and plating process, etc.

关键词:

An on-line monitoring system for hydrogen distribution metallic wall caused by hydrogen permeation

Gang YU , Xueyuan ZHANG , Yuanlong DU

材料科学技术(英文)

Based on the electrochemical permeation technique and the patent by Du, an intelligent electrochemical measurement system for determination of the hydrogen distribution in the wall of hydrogenation reactor has been developed and tested. It consists of a PC computer, a single chip unit, an I/V converter and an electrochemical hydrogen probe. The construction of the electrochemical hydrogen probe is described and the features of the measured system are given. The diffusion coefficient of 2.25Cr1Mo steel determined with present system was in good agreement with the value in the literature. Experimental results of hydrogen concentration in a wall of hydrogen charged testing autoclave made of AISI 321 stainless steel are presented. The present system can intelligently display hydrogen amount-of-substance concentration and mass fraction concentration, hydrogen concentration distribution curves in steels, permeation current density curve. An intelligent detection technique can be provided for predicting the susceptibility to hydrogen-induced cracks owing to hydrogen permeation in the wall of hydrogenation reactor in the field.

关键词:

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Broer-Kaup-Kupershmidt方程的新精确解

杨立娟 , 杨琼芬 , 杜先云

量子电子学报 doi:10.3969/j.issn.1007-5461.2012.02.003

CK方法是求解非线性发展方程的一种有效的直接方法.利用推广的CK方法,求得(2+1)维Broer-Kaup-Kupershmidt方程的Backlund公式,从而获得方程的大量新的精确解,推广了Xu和Zhang的结果.

关键词: 非线性发展方程 , Broer-Kaup-Kupershmidt方程 , 精确解 , CK方法 , Backlund变换

Three-dimensional (3D) Ising universality in magnets and critical indices at fluid-fluid phase transition

Phase Transitions

Experimental data for critical exponents in some magnetic materials are compared with recent theoretical results on the three-dimensional (3D) Ising model, as derived by one of us (ZDZ) based on two conjectures [Z.D. Zhang, Conjectures on the exact solution of three-dimensional (3D) simple orthorhombic Ising lattices, Phil. Mag. 87 (2007), pp. 5309-5419]. It is found that critical exponents in some bulk magnetic materials indeed form a 3D Ising universality. Our attention is then focused on the critical indices at fluid-fluid phase transition. We suggest to use Zhang's exponent = 3/8 to fit the experimental data over the wider asymptotic region near the critical point of a fluid-fluid phase transition. The 3D Ising universality should exist for critical indices in a certain class of magnets and at fluid-fluid phase transition.

关键词: magnetically ordered materials;fluid-fluid;phase transitions;order-disorder effects;ferromagnetic curie temperature;liquid critical phenomena;x-ray-scattering;critical exponents;critical-point;coexistence;curves;binary-solutions;ionic-solutions;behavior;equation

Response to the Comment on 'Conjectures on exact solution of three-dimensional (3D) simple orthorhombic Ising lattices'

Philosophical Magazine

The error of Equation (15b) in my article [Z.D. Zhang, Phil. Mag. 87 (2007) p.5309] in the application of the Jordan-Wigner transformation does not affect the validity of the putative exact solution, since the solution is not derived directly from that equation. Other objections of Perk's comment [J.H.H. Perk, Phil. Mag. 89 (2009) p.761] are the same as those in Wu et al.'s comments [F.Y. Wu et al., Phil. Mag. 88 (2008) p.3093; p.3103], which do not stand on solid ground and which I have sought to refute in my previous response [Z.D. Zhang, Phil. Mag. 88 (2008) p.3097]. The conjectured solution can be utilized to understand critical phenomena in various systems, whereas the conjectures are open to rigorous proof.

关键词: 3D Ising model;exact solution;conjecture;critical phenomena;ferromagnetism;magnetic phase transition;model;analyticity

不同掺杂的钇系-123薄膜磁通特性

张鹰子 , 王志 , 向建勇 , 闻海虎

低温物理学报 doi:10.3969/j.issn.1000-3258.2005.z1.087

我们在磁场中分别测量了最佳掺杂的YBa2Cu3O7-δ、钙0.2掺杂的Y1-xCaxBa2Cu3O7-δ及钙0.5掺杂的Pr1-xCaxBa2Cu3O7-δ薄膜的电阻温度关系.利用最近Zhang et al. [Phys. Rev. B 71(2005), 052502 ]提出的热激活能的分析方法对薄膜的磁通特性进行了分析、比较与讨论.

关键词: Y-123薄膜 , 涡旋特性 , 激活能

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....

关键词:

Proposed magnetic equation of state for the three-dimensional Ising model near criticality: Is the insulating ferromagnet CrBr(3) a candidate?

Physics Letters A

In a magnetic system, consistent with Griffiths analyticity requirements one can parameterize the equation of state near criticality by writing H = r(beta delta)h(theta), T = rt(theta) and the magnetization M = r(beta)m(theta), where T is measured from the critical temperature. For the insulating ferromagnet CrBr(3), the experimental data of Ho and Litster [J.T. Ho, J.D. Litster, Phys. Rev. Lett. 22 (1969) 6031 is well fitted by m(theta) as a linear function of theta [P. Schofield, J.D. Litster, J.T Ho, Phys. Rev. Lett. 23 (1969) 1098]. Also Ho and Litster give beta = 0.368, gamma = 1.215 and delta = 4.3. Those critical experiments are very close to the recent 31) king results of Zhang [Z.D. Zhang, Philos. Mag. 87 (2007) 5309], namely beta = 3/8, gamma = 5/4 and delta = 13/3. We therefore predict that m(theta) will be proportional to theta as a fingerprint of the 3D Ising Hamiltonian. (C) 2009 Elsevier B.V. All rights reserved.

关键词: Critical-point effects;Critical exponents;Ising model;Criticality;Ferromagnet;Magnetic equation of state;critical exponents

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