O.H. Ibrahim
材料科学技术（英文）
The impact properties of hot rolled carbon steel (used for the manufacture of reinforcement steel bars) and the quenched & tempered (Q&T) low alloy steel (used in the pressure vessel industry) were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200°C. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q&T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the di®erence in the chemical composition and microstructure for the two steels.
关键词:
Ferritic/pearlitic steel
FANG Zheng CHEN Xinmin(H.M.Chen) Central South University of Technology
,
Changsha
,
China FANG Zheng
,
Associate Professor
,
Department of Chemistry
,
Central South University of Technology
,
Changsha
,
China
金属学报(英文版)
By taking the effect of oxygen contents into account,a new set of formulae which represents the oxygen potentials of H_2O-H_2 and H_2O-H_2-inerts gas mixtures has been derived.Classi- cal representation is only a particular case of it.Some of the variables affecting equilibrium atmosphere when trace oxygen is present and optimum preparation of the gas mixtures to min- imize errors have been discussed.The reliability of some of previous equilibrium experiments under the oxygen potentials controlled by H_2O-H_2 or H_2O-H_2-inerts gas mixtures has also been criticized.
关键词:
gas equilibration method
,
null
,
null
,
null
李建权
,
程平
,
王鸿梅
,
王占新
,
储焰南
,
周士康
量子电子学报
doi:10.3969/j.issn.1007-5461.2004.03.005
在流动余辉质谱装置上,利用He的空心阴极放电产物与H2O反应制备了反应物离子H3O+(H2O)n(n=0～4),并观察了H3O+(H2O)n(n=0～4)与CH3OH、C2H5OH反应的产物离子,对它们进行了归属,分析了各种产物离子形成的离子-分子反应机制.
关键词:
光谱学
,
流动余辉质谱
,
甲醇
,
乙醇
王秋亚
,
焦华
,
朱海燕
人工晶体学报
以芒柄花素为先导化合物,合成了水溶性的[Co(H2O)6](C18H15O4SO3)2·4H2O,并采用IR, 1H NMR, TG-DTA, XRD和单晶X射线衍射法对其结构进行了表征.单晶X射线衍射结果表明:[Co(H2O)6]2+、C18H15O4SO 3和H2O之间存在多种氢键,形成晶体结构中的亲水区.异黄酮骨架间反平行排列,面对面和边对面芳香堆积作用同时存在于其中,构成晶体结构中的疏水区.磺酸根是连接亲水区和疏水区的桥梁.氢键、芳香堆积作用以及阴阳离子之间的静电引力共同将标题化合物组装成具有三维网络结构的超分子.
关键词:
芒柄花素
,
[Co(H2O)6](C18H15O4SO3)2·4H2O
,
晶体结构
,
芳香堆积
,
氢键
邵明增
,
崔立山
,
郑雁军
,
邢琳琳
,
张小洁
,
王一雄
腐蚀学报（英文）
随着工业的发展, 富Cr合金在H2-H2O气氛下的氧化行为越来越常见. 与空气等氧化性气氛相比, 在H2-H2O气氛中, 富Cr合金形成的氧化膜的抗剥落性能、形貌、合金的氧化速率以及活性元素对其影响等都有较大区别, 本文从以上几个方面综述了H2-H2O气氛下富Cr合金氧化行为的研究进展.
关键词:
氧化
,
H2-H2O
,
Cr-rich alloy
邵明增
,
崔立山
,
郑雁军
,
邢琳琳
,
张小洁
,
王一雄
腐蚀学报（英文）
随着工业的发展,富Cr合金在H2-H2O气氛下的氧化行为越来越常见.与空气等氧化性气氛相比,在H2-H2O气氛中,富Cr合金形成的氧化膜的抗剥落性能、形貌、合金的氧化速率以及活性元素对其影响等都有较大区别,本文从以上几个方面综述了H2-H2O气氛下富Cr合金氧化行为的研究进展.
关键词:
氧化
,
H2-H2O
,
富Cr合金
王其祥
,
宋宝珍
,
李洪钟
无机材料学报
doi:10.3321/j.issn:1000-324X.2001.05.013
采用H2+H2O还原法,通过控制H2O/H2比可改善粉体晶粒链状结构的晶间界面结构,采用XRD、TEM、VSM等方法测试粉体的晶体结构、粒子形貌和磁性能.结果为金属磁粉的矫顽力提高;粒子形状均匀,表面平滑,毛刺少;460℃时H2+H2O还原金属磁粉的矫顽力为1520Oe,比传统氢还原工艺矫顽力1440Oe提高5.6%.采用流化床反应器,具有温度均匀,气固接触充分,可防止颗粒烧结等优点,工业应用前景广阔.
关键词:
金属磁记录粉
,
H2/H2O还原
,
晶粒链状结构
程平
,
王鸿梅
,
李建权
,
张为俊
,
曹德兆
,
储焰南
量子电子学报
doi:10.3969/j.issn.1007-5461.2003.03.006
利用微波放电电离质谱装置,分别通过N2与O2、水蒸气与空气的微波放电,产生了大气中存在的NO+和H3O+.(H2O)n离子,动力学过程的分析和讨论表明这几种离子是由大气中的初始反应离子N+2、N+、O+2、O+与周围环境中的原子、分子经过一系列的离子-分子反应产生的.这一结论也同时模拟了大气中NO+和H3O+.(H2O)n的形成过程.
关键词:
微波放电
,
大气
,
离子化学
Physical Review B
Based upon the full-electron ab initio calculations, we found orientational preferences and correlation for the atop-to-atop motions of an H2O on Al{100}, which originates from the symmetry match between an H2O and the surface square lattice. We have provided theoretical evidence that the favored mechanisms can be classical hopping coupled with either the molecular flipping or in-plane reorientations, with reduced energy barriers compared to those of the simple translational motions; while quantum tunneling assisted motion is not favored for an H2O via the nearest neighbor diffusion.
关键词:
synchronous-transit method;molecules;water;chemistry;surfaces;pd(111);points;solids
