LI Lin
,
TANG Guangsheng
,
HE Zhiyong
,
et al
钢铁研究学报(英文版)
Carbon black-phenolic resin composite binders with various amounts of nanometer carbon black were prepared through adding KH-550 coupling agent and high-speed mixer. The effects of nanometer carbon black amount added on viscosity of the composite binders were studied. Low carbon MgO-C specimens were fabricated with these composite binders. Effects of nanoscale carbon black contents (0, 2.5%, 5%, 10%, and 15% of phenolic resin in mass) on mechanical properties of low carbon MgO-C specimens were investigated. The results revealed that the viscosity of the composite binder increased rapidly with increase of nanometer carbon black content. Moreover, it indicated that CMOR, HMOR and CCS of the specimens rose gradually with increase of nanometer carbon black content as well.
关键词:
Black carbon;performancr;Mgo-C composite
LIU Bo
,
SUN Jialin
,
TANG Guangsheng
,
et al
钢铁研究学报(英文版)
Abstract: The low-carbon magnesia–carbon (MgO-C) composites containing 3% (mass fraction, the same below) carbon were prepared by adding various types of carbon black (CB). The mechanical properties, oxidation resistance at 1100℃ in oxidizing atmosphere, and thermal shock resistance after 5 times dipping in 1600 ℃ molten-steel of the low-carbon composite samples were investigated, compared with a commercial high-carbon MgO-C composite containing 16% carbon. The results show that the mechanical properties, oxidation resistance and thermal shock resistance of the low-carbon samples improve with the decrease of CB particle size. Thermal shock resistance of the low-carbon sample containing nanometer CB N220 is obviously better than other low -carbon samples, and reaches the level of the high-carbon samples.
关键词:
magnesia-carbon composite;low-carbon content;nanometer carbon black;thermal shock resistance;refractory
金属学报
Volu扣ne 27SeriesB1991AUTHOR INDEX CCAO Guanghan(曹光旱)············……6一B科6CAo weijie(曹卫恋)..················……5一B32oCAO Yilin(曹益林)··················……6一B443CHANG Xin(常听)···············……1一B48CHE Guang邻n(车广灿)·············一6一B科0CHEN Erbao(陈二保)···············……6一B410CHEN Jia....
关键词:
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:
Acta Physica Sinica
Molecular dynamics (MD) simulation is performed to study the vacancy-interstitial annihilation in crystalline silicon. We choose the Stillinger-Weber potential, which is commonly used for silicon, to describe the interaction between atoms. The system is relaxed under 300K and 1400K respectively. We have found that < 111 > is the preferred recombination direction and propose the presence of an energy barrier in the < 110 > direction. From the calculated value of energy barrier along < 110 > we give a reasonable explanation for the difference between Tang's and Zawadzki's data.
关键词:
molecular dynamics;vacancy and interstitial;diffusion;point-defects;diffusion;mechanisms
Physical Review B
We reconsider and interpret the mechanical properties of the recently proposed allotrope of carbon, T-carbon [Sheng et al., Phys. Rev. Lett. 106, 155703 (2011)], using density functional theory in combination with different empirical hardness models. In contrast with the early estimation based on Gao et al.'s model, which attributes to T-carbon a high Vickers hardness of 61 GPa comparable to that of superhard cubic boron nitride (c-BN), we find that T-carbon is not a superhard material, since its Vickers hardness does not exceed 10 GPa. Besides providing clear evidence for the absence of superhardness in T-carbon, we discuss the physical reasons behind the failure of Gao et al.'s and Simunek and Vackar's (SV) models in predicting the hardness of T-carbon, residing in their improper treatment of the highly anisotropic distribution of quasi-sp(3)-like C-C hybrids. A possible remedy for the Gao et al. and SV models based on the concept of the superatom is suggested, which indeed yields a Vickers hardness of about 8 GPa.
关键词:
superhard rhenium diboride;elastic-constants;ambient-pressure;metal;borides;crystals;diamond;search;boron
李凤娟
,
吕国光
金属世界
doi:10.3969/j.issn.1000-6826.2014.04.14
通过对烧结配料所需原料及对冷烧结矿成品检验采制样方法的分析,找出影响检验结果真实性的因素,采取有效的改进措施,使本钢原料厂一次配料、本钢炼铁厂265 m2烧结二次配料及265 m2烧结系统各项稳定率有了很大的提高,烧结矿实物质量和各项技术质量指标有了很大的进步,保证了高炉的稳定顺行。
提高本钢265 m2冷烧结矿及原料检验代表性的实践
Practice of Improving the 265 m2 Cold Sinter and Raw Material Inspection Representative
供稿|
李凤娟,吕国光/
LI Feng-juan, LV Guo-guang
DOI:10.3969/j.issn.1000-6826.2014.04.14
导读内容
本钢炼铁厂265 m2烧结机生产所需要的含铁原料比较复杂,一次配料料种较多,且烧结含铁原料是由本钢原料厂二车间供料,原料质量的不稳定,会影响烧结矿质量的提高和新一号高炉的强化及高炉技术指标的改善。本钢质量管理中心驻冷烧检查站加强了对烧结配料所需原料及对冷烧结矿成品检验采制样代表性的研究,采取了一些改进措施,达到了良好的效果。含铁料成分稳定率、烧结矿各项质量和技术指标在稳步地提高。下面,对本钢质量管理中心驻冷烧检查站就提高采样及检验过程的准确性所采取的措施和办法进行说明。
烧结矿采样是半自动采样,每两小时采样一次,作为一个批次,来代表整个2h烧结矿的成份。
关键词:
陈修帅
,
侯传金
,
李晴
,
刘彦军
,
杨瑞丰
,
胡向平
催化学报
doi:10.1016/S1872-2067(16)62488-9
手性2,3-二氢呋喃衍生物是一类重要的杂环化合物,广泛存在于天然产物和生物活性分子中.它们也经常被用于手性四氢呋喃化合物的不对称合成.因此,人们发展了很多合成手性2,3-二氢呋喃化合物的方法,如有机小分子催化的多米诺迈克尔-烷基化反应、“中断的”Feist-Bénary反应或改进的 Feist-Bénary反应.此外,过渡金属催化的手性2,3-二氢呋喃的不对称合成在近些年引起了人们的极大关注. Ozawa等通过 Pd-催化2,3-二氢呋喃的动力拆分方法获得了手性2-芳基-2,3-二氢呋喃. Evans发展了一种 Sc-催化联烯硅和乙醛酸乙酯的[3+2]环加成反应合成手性2,3-二氢呋喃的方法.最近, Fu和 Tang等发展了 Cu催化烯酮和重氮化合物的[4+1]环加成反应合成手性2,3-二氢呋喃的方法.在 Nishibayashi和 van Maarseveen的开创性工作之后, Cu催化的不对称炔丙基转化反应取得了很大的进展.最近,我们发展了一类新的三齿手性 P,N,N-配体,在 Cu催化不对称炔丙基取代、脱羧炔丙基取代、[3+2]、[3+3]和[4+2]环加成反应中表现出优秀的对映和非对映选择性.其中,我们发现采用 Cu催化炔丙醇酯和β-酮酯的[3+2]环加成反应,能高对映选择性地获得手性2,3-二氢呋喃.我们设想,采用β-羰基膦酸酯代替β-酮酯,通过这种 Cu催化[3+2]环加成反应,将可以合成一类具有重要生物活性的手性膦酰化2,3-二氢呋喃化合物.基于这种设想,本文使用手性 P,N,N-配体,通过 Cu催化炔丙醇酯与β-羰基膦酸酯的不对称[3+2]环加成反应,以很好的收率和最高92% ee的对映选择性获得了一系列光学活性的膦酰化2,3-二氢呋喃化合物.我们以炔丙醇酯1a与β-羰基膦酸酯2a为标准底物,优化了反应条件,考察了配体、Cu盐、碱和反应温度等对反应收率和对映选择性的影响.我们确定了最佳的反应条件:以4b为配体,以 Cu(OTf)2为铜盐,以t-BuOK为碱,以 MeOH为溶剂,–20oC反应24 h.在此条件下,我们对β-羰基磷酸酯2的适用范围进行了考察.结果表明,各种苯基取代的β-羰膦磷酸酯均能得到很好的收率和对映选择性.苯环上取代基的空间效应对反应的对映选择性影响不大,但对反应收率影响较大,与相应3-取代或4-取代底物相比较,2-取代的底物获得的收率较低.苯环对位取代基的电子效应对反应的影响不大,给电子基或吸电子基的底物,均得到了较好的收率和对映选择性.杂环取代的底物同样适用于该反应,以90%的收率和89% ee的对映选择性获得了相应的[3+2]环加成产物.对于烷基底物,虽然反应的产率略低,但是得到了高达92% ee的产物.此外,我们对炔丙醇酯底物的适用范围也进行了考察.结果表明,该体系对于各种取代的炔丙醇酯底物均可以获得较高的收率和良好的对映选择性.总之,本文发展了一种铜催化炔丙醇酯与β-羰基膦酸酯的不对称[3+2]环加成反应的方法,成功合成了手性膦酰化2,3-二氢呋喃化合物.通过使用一个结构刚性的酮亚胺三齿 P,N,N-配体,以很好的收率和最高92% ee的对映选择性获得了一系列光学活性的膦酰化2,3-二氢呋喃化合物.
关键词:
铜
,
不对称合成
,
3+2环加成
,
β-羰基膦酸酯
,
膦酰化 2,3-二氢呋喃