材料期刊网

THE EFFECT OF BORON AND CARBON ADDITION ON WELDABILITY OF DS TMS-75 SUPERALLOY

M.C.Chaturvedi , Y.L.Wang , N.L.Richards

金属学报(英文版)

Four alloys TMS-75 (Base), Base+B, Base+C and TMD-103 (Base+B+C) with varying levels of B, C were directionally solidified (DS), and their weldability was investigated by bead-onplate electron beam welding. It was found that cracking occurred in the weld-metal, as well as in the heat affected zone (HAZ). Both γ/γ' and/or γ/carbide eutectic contributed to the weld-metal cracking, and theγ/γ' eutectic was found to be mainly responsible for cracking in HAZ. However, constitutional liquation of carbides seems to have made some contribution also.The B addition had a detrimental effect on HAZ cracking susceptibility, while C addition improved it appreciably even in the presence of B. In addition, no obvious differences were observed in cracking susceptibility of weld-metal in the four alloys. The cracking modes and mechanisms underlying the effect of B and C addition on weidability could be explained on the basis of microstructures of the four alloys.

关键词: Ni-based superalloy , null , null

Nω-羟基-nor-L-精氨酸的合成

滕汉兵

应用化学 doi:10.3724/SP.J.1095.2010.90811

以Nα-Boc-L-谷氨酰胺为原料,合成了精氨酸酶抑制剂Nω-羟基-nor-L-精氨酸的二盐酸盐. 合成过程由文献中7步操作整合为4步,减少了中间体的分离步骤,使总收率由21%提高至37%.

关键词: 精氨酸酶抑制剂 , 氨基保护 , 合成

The ferromagnetic copper (II)-azido compound Cu(L)(2)(N-3)(2) (n) L=4-(dimethylamino)pyridine studied by first-principle calculation

Physica B-Condensed Matter

Cu2+ ions are doubly bridged by asymmetrical end-to-end (EE) azido groups in copper (II)-azido compound [Cu(L)(2)(N-3)(2)](n) [L = 4-(dimethylamino)pyridine]. The electronic structure of its ferromagnetic ground state has been calculated using the self-consistent full-potential linearized augmented plane wave method (FP_LAPW) based on the density functional theory (DFT). The result shows that spin distribution and ferromagnetic coupling in the title compound are dominated by the spin delocalization effect from Cu2+ ions toward the azido groups, but weak spin polarization effects also contribute to the magnetic coupling through the asymmetrical EE azido groups. (c) 2005 Elsevier B.V. All rights reserved.

关键词: [Cu(L)(2)(N-3)(2)](n);azido group;spin delocalization;end-to-end;magnetostructural correlations;magnetic-properties;molecular magnets;crystal-structure;on azido;antiferromagnetic;interactions;nickel(ii) complexes;dinuclear complex;bridges

胆固醇-(L-乳酸)n低聚物的微波合成及性能

李彩荣 , 丁珊 , 罗丙红 , 文伟 , 周长忍

高分子材料科学与工程

在微波辐射作用下,以辛酸亚锡为催化剂,胆固醇为共引发剂引发L-丙交酯开环聚合制备了一组胆固醇-(L-乳酸)n低聚物(G-LAn),采用红外光谱、核磁共振氢谱、凝胶渗透色谱、差示扫描量热法、偏光显微镜和小角X射线衍射研究了产物的结构与性能.结果表明,C-LAn低聚物的相对分子质量可以通过改变n(胆固醇)∶n(L-丙交酯)值进行调控,其结构是由胆固醇端基和聚乳酸螺旋链构成的层状结构;C-LAn低聚物兼有结晶性和液晶性,且受低聚物分子中聚(L-乳酸)链段的长度影响,随着聚(L-乳酸)链段增长,低聚物呈现液晶态的温度区间变窄、温度升高.

关键词: 聚(L-乳酸) , 胆固醇 , 微波合成 , 液晶 , 结晶

医用316L不锈钢支架表面沉积(Fe/Pd)n薄膜的研究

胡涛 , 李争显 , 麻西群 , 周廉 , 介万奇 , 王海昌

稀有金属材料与工程

采用真空电弧离子镀技术,在医用316L不锈钢支架上沉积近等原子比的(Fe/Pd)n多层膜.用X射线衍射、扫描电镜、电子能谱研究(Fe/Pd)n多层膜的晶体结构、形貌和成分,分析相的转变.用CTCC-1数字磁通磁场测量仪测量样品的磁性.结果表明:医用316L不锈钢支架表面磁性膜的最佳结构为"Pd/Fe/Pd",经扩散热处理后,(Fe/Pd)n薄膜从fcc结构转变为fct结构,薄膜均匀、致密、结合强度良好,有效磁场强度可达5×10-4 T以上,有效磁性可维持6个月.

关键词: 316L不锈钢 , 磁性薄膜 , 电弧离子镀 , (Fe/Pd)n薄膜

混合溶剂热法制备[Zn(L-trp)(D-trp)]n

王建 , 许兴友 , 马卫兴 , 赵宏 , 陆路德 , 杨绪杰 , 汪信

人工晶体学报

新型氨基酸配位聚合物[Zn(L-trp)(D-trp)]n(L-trp和D-trp分别是L-色氨酸和D-色氨酸)通过水热法制备,并进行元素分析、红外光谱、单晶X-衍射等的表征.该化合物属三斜晶系,P-1,a=0.91670(10)nm,b=0.53320(6)nm,c=1.9525(2)nm,Z=2.为二维双链平面结构.此配位聚合物具有中心对称空间群.每个锌离子Zn2+与一对外消旋体配合,而形成内消旋化合物.

关键词: 色氨酸 , Zn(Ⅱ)配位聚合物 , 混合溶剂热法 , 表征

藻毒素β-N-甲氨基-L-丙氨酸(BMAA)的氯化降解

曹雨 , 鲜啓鸣

环境化学 doi:10.7524/j.issn.0254-6108.2016.02.2015073102

本文建立了高效液相色谱-串联质谱法(HPLC-MS/MS)来检测水中BMAA,并以次氯酸钠为消毒剂进行模拟氯化,研究BMAA的氯化降解及环境因子对BMAA降解的影响.结果表明,采用亲水交换作用色谱柱建立的HPLC-MS/MS分析方法,样品前处理过程简单易操作,在2-500 μg·L-1范围内线性关系良好(R2=0.9995),且检出限低(0.2μg·L-1).在常规条件下(Cl∶N=2∶1,T=20℃,pH=7),BMAA能通过氯化得到有效降解,2h降解率达到80％,6h降解率达到97％;低的C1:N,低温及碱性条件下,BMAA的降解率显著降低.研究结果为饮用水预氯化及氯化消毒去除BMAA提供了理论依据.

关键词: β-N-甲氨基-L-丙氨酸(BMAA) , 高效液相色谱-质谱 , 模拟氯化 , 降解

Ab initio study of the electronic structure and the magnetic properties of polymers Co N(CN)(2) (2)(L) L = pyrazine dioxide (pzdo) and 2-methyl pyrazine dioxide (mpdo) with dual mu- and mu 3- N(CN)(2) (-) bridges

Journal of Magnetism and Magnetic Materials

The first principle within the full potential linearized augmented-plane-wave (FP-LAPW) method was applied to study the compound of Co[N(CN)(2)](2)(L) [L = pyrazine dioxide (pzdo) and 2-methyl pyrazine dioxide (mpdo)] with dual mu- and mu 3-[N(CN)(2)](-) bridges. The density of states, the electronic band structure and the spin magnetic moment are calculated. The calculations reveal that these two compounds have a ferromagnetic (FM) interaction arising from the 1,5-mu- and mu 3-[N(CN)(2)](-) bridges. The spin magnetic moment mainly comes from the Co ion with little contribution from N, O and C anions. (C) 2007 Elsevier B.V. All rights reserved.

关键词: ab initio;FP-LAPW;electronic structure;ferromagnetic property;networks;molecule;ni;co

The magnetic behavior and electronic structure of manganese (II)-azido complex Mn(L)(2)(N3)(2) (n) studied by first-principle calculation

Physics Letters A

Manganese (II)-azido complex [Mn(L)(2)(N3)(2)](n) (L=4-cyanopyridine) has been studied with the self-consistent full-potential linearized augmented plane wave method (FP-LAPW) based on the density functional theory (DFT). Spin distributions in ferromagnetic and antiferromagnetic states of it have been obtained by the calculation. The result shows that magnetic coupling through azido groups should be attributed to the spin delocalization effect. (c) 2006 Elsevier B.V. All rights reserved.

关键词: [Mn(L)(2)(N3)(n)];azido group;end-on azido;copper(ii) dinuclear complex;crystal-structure;antiferromagnetic interactions;magnetostructural correlations;ferromagnetic interaction;nickel(ii) complexes;compound;ligand;perchlorate

N-(4-吡啶甲基)-L-丝氨酸铜配合物的合成、晶体结构和磁性

李艳红 , 卢丽萍 , 冯思思

人工晶体学报

氨基酸还原希夫碱HL (N-(4-吡啶甲基)-L-丝氨酸)与CuCl2·2H2O在室温条件通过扩散法合成了配位聚合物{[Cu2(L)2(Cl)2]·H2O}n(I).采用元素分析、红外光谱、X-射线单晶衍射、粉末衍射和热重分析进行了表征.两个结晶学独立Cu(II) 包含于其晶体结构中,Cu1为变形八面体CuO2N2Cl2几何构型;Cu2则呈现略有变形的四方锥结构.Cu1和Cu2通过配体L-的吡啶氮原子以及氯离子的桥连作用连接为2D网状结构.变温磁化率实验表明在温度为2~300 K,配合物I表现为铁磁性耦合.

关键词: N-(4-吡啶甲基)-L-丝氨酸 , 配位聚合物 , 晶体结构 , 铁磁性