混合稀土对共晶Al-2％Fe合金组织形态的影响

研究了富La混合稀土对共晶Al-2％Fe合金组织形态的影响。当混合稀土加入量较少时，合金中的α—Al相为明显的胞状枝晶；随着混合稀土加入量的增加，α-Al枝晶优先形核生长得到抑制，共晶Al3Fe相得到细化；当稀土加入量增至0．6％(质量分数)共晶Al3Fe相尺寸逐渐增大。并对混合稀土对共晶Al-2％Fe合金组织形态的影响机制进行了探讨。     

混合稀土对共晶Al-2%Fe合金组织形态的影响

研究了富La混合稀土对共晶Al-2?合金组织形态的影响. 当混合稀土加入量较少时, 合金中的α-Al相为明显的胞状枝晶;随着混合稀土加入量的增加, α-Al枝晶优先形核生长得到抑制, 共晶Al3Fe相得到细化;当稀土加入量增至0.6% (质量分数)共晶Al3Fe相尺寸逐渐增大. 并对混合稀土对共晶Al-2?合金组织形态的影响机制进行了探讨.     

钕对Mg7Zn2Al镁合金显微组织及力学性能的影响

采用光学显微镜、XRD、SEM和万能实验机等手段研究了稀土Nd(0.3%,0.6%,0.9%)对Mg7Zn2Al镁合金显微组织和力学性能的影响。结果表明:Mg7Zn2Al镁合金中添加Nd后,显微组织中有针状或棒状的Al2Nd和AlNd等稀土相生成,合金中的共晶组织(α-Mg+Mg32(Al,Zn)49+Mg7Zn3)得到了明显细化;但是α-Mg有粗化趋势,呈现发达的树枝状或胞状,共晶相由粗大连续的网状变为细小的块状或颗粒状分布在树枝晶的一次枝晶臂或二次枝晶臂的间隙。随着Nd含量的增加,合金的抗拉强度和延伸率呈逐渐下降趋势,显微组织的粗化是造成合金拉伸性能降低的主要原因,而硬度没有明显的变化。     

微量元素La对Al—Si合金凝固过程的影响

本文用差热分析法系统地研究了La掺杂对Al-Si共晶合金、亚共晶、超共晶的动态凝固过程的影响。结果表明,La促使α(Al)成核,使体系中初晶α(Al)的析出温度比AJ-Si二元合金中Al初晶的实际析出温度明显提高;La对初晶Si的成核和长大起抑制作用,使超共晶中初晶Si相析出温度较二元合金中的Si初晶的实际析出温度明显降低。     

Al-Ni-Y三元共晶合金高压凝固组织

利用光学显微镜,扫描电镜,X射线衍射仪对不同压力(2,4,6 GPa)下凝固的Al-1Ni-3Y(%,原子分数)共晶合金组织形貌和相组成进行研究,并且与常压条件下合金凝固组织进行对比。实验结果表明,与常压凝固相比,在超高压力条件下凝固的合金的显微组织形貌发生了很大的改变,但是合金的相组成没有发生变化。常压凝固的合金具有共晶团组织,而高压下凝固的合金具有枝晶状亚共晶组织。高压凝固合金显微组织中出现了大量的初生α-Al相,这表明高压条件下凝固的合金共晶点发生偏移,使得常压共晶成分的合金在高压下变成亚共晶成分合金。同时,共晶组织的形貌发生了很大变化,常压下凝固的合金的组织为Al3Y相与α-Al相形成的菊花状的二元共晶和Al23Ni6Y4相与α-Al相形成的层片状的二元共晶,而高压下这两种共晶组织逐渐转化为离异共晶组织。随着压力的增大,共晶第二相的体积分数减小,α-Al的晶格常数增加。     

4GPa超高压凝固Mg-6Zn-3Y合金的凝固组织及相分析

利用X射线衍射仪、扫描电镜并配合能谱分析研究了Mg-6Zn-3Y合金4 GPa超高压凝固组织.结果表明:在4 GPa超高压条件下凝固时,实验合金的凝固组织得到显著细化,基体α-Mg相的晶格间距有所减小;Zn在基体α-Mg中溶解度大幅提高,Y不溶于基体α-Mg;实验合金凝固组织中出现呈对称性的四瓣或六瓣花的初晶Y固溶体,该初晶花瓣形貌完整、尺寸较大,显示其充分自由生长;先发生的共晶反应的共晶组织为成“簇”分布的共晶团,共晶相呈点状或棒状;后发生的共晶反应的组织为离异共晶.超高压凝固显著地改变了实验合金的凝固过程.     

稀土元素在Al—Mg合金中的分布及对结晶组织的影响

应用控制凝固技术研究了定向凝固条件下Al-Mg合金的凝固过程,并着重考察了稀土在合金中的分布及对结晶组织和枝晶间距的影响。结果表明,微量稀土元素不溶于α-Al,而多在枝晶边界富集;加入稀土元素增大了合金熔体的组成过冷,较显著地影响合金的结晶形貌,并使枝晶间距减小。     

铝钛硼稀土中间合金的微观组织及其细化纯铝机制研究

采用氟盐与稀土铝水反应法制取Al5Ti4RE1B中间合金,对其进行物相、微观组织和细化效果分析,通过深入观察细化处理后晶粒形貌和微区成分分析对细化机制进行了研究。XRD及EDS分析显示RE和TiAl3结合生成了Ti2Al20RE相,细化试验表明Al5Ti4RE1B比Al5Ti1B具有更强的细化能力。微观组织及面扫描结果显示细化后的晶粒呈菊花状,在花瓣的不同位置存在RE和Ti分布的不均匀性,热处理后晶粒花瓣减少,成分也趋于均匀。这是由于Ti2Al20RE相在铝液中逐渐溶解并释放出RE和Ti原子,而-αAl晶体以枝晶的方式生长,同时将稀土原子排到枝晶间,最终形成了菊花状组织及元素分布的不均匀性。     

电脉冲作用下共晶铝硅合金凝固组织的变化

本文研究了连续电脉冲处理对共晶铝硅合金凝固组织的影响.结果显示,电脉冲处理后Al-12.5%Si共晶合金的凝固组织中出现了本应在过共晶成分的铝硅合金中才会出现的初生硅.X-射线能谱分析表明,电脉冲处理后α-Al枝晶中固溶Si含量降低.     

微量元素Sr对Al—Si合金凝固过程的影响

用差热分析法系统地研究了Sr对Al-Si共晶、亚共晶及超共晶合金的动态凝固过程的影响。结果表明,Sr既可促进α-Al成核,使其初晶析出温度比二元合金中α-Al相析出温度明显提高,又能抑制初晶Si成核,使超共晶中初晶Si相析出温度较二元合金中Si的初晶的实际析出温度明显降低,还能促使共晶合金成核,使加Sr后的共晶析出温度明显提高。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。