分子磁交换机理研究进展

概述了分子磁交换的机理研究及其进展。介绍了直接交换、超交换和双交换三种作用机理及基于自旋密度分析的自旋极化和自旋离域作用机制，并对今后分子磁性的理论研究作了展望。     

流动注射离子选择电极法自动测定阳离子交换树脂交换容量的研究

基于流动注射离子选择电极法(FIA-ISE)测定痕量Na 原理,建立了一种能自动测定阳离子交换树脂各种交换性能的方法,对影响阳阳离子交换树脂交换容量的各种因素进行考察,筛选出凝胶型强阳离子交换树脂(SACR)交换性能测定的最佳条件:微型交换柱内径3.0mm、长80mm;树脂填充量0.1951g;再生剂HCl浓度为3.0%,其流速为0.90mL/min(7.64m/h),再生剂耗量350mL/g(干树脂);样品为20mg/LNa 溶液,其流速为1.50mL/min;实现了一次测定同时获得SACR的工作交换容量、平衡交换容量、全交换容量、交换速率和树脂利用率。与ASTM法进行对照实验,其结果相关性良好(r=0.9922)。     

用流动注射分析法测定强碱性阴离子交换树脂的交换容量

建立了快速测定微量氯离子的FIA分光光度法和快速测定强碱性阴离子交换树脂交换容量的FIA法。本方法将离子交换微型柱导入树脂交换容量的测定中 ,不但获得了很好的精度 (RSD <0 .9% ) ,而且使测定效率提高了近 30倍。优选实验得到的最佳测定条件为再生液流速 0 .5mL/min ,再生剂用量 :333mL/ g,再生剂浓度 :3.0 % (W /V) ;样品液流速 :1 .5mL/min ;树脂交换容量测定温度 :2 5℃± 5℃。     

偏二甲肼在阳离子交换柱上的交换过程

研究了不同浓度的偏二甲肼在树脂上的交换过程 ,其交换行为用流出曲线来表示 .文中还对影响流出曲线的各种主要因素进行了探讨 .通过实验发现 1#树脂的交换效果最好 ,贯穿点前的流出液完全符合浓度≤0 5mg/L的排放达标要求 ,而料液浓度、流速、不同类型树脂是影响交换最关键的因素 .     

稻壳纤维素强酸性阳离子交换剂

交换容量;重金属离子;稻壳纤维素强酸性阳离子交换剂     

基于FIA-ISE测定WACR交换性能的研究

基于FIA-ISE测定痕量Na~+原理,建立了一种自动测定弱酸性阳离子交换树脂(WACR)交换性能的方法.本研究对WACR交换性能的各影响因素进行考察,优选出其测定条件:微型交换柱内径3.0mm、长80mm;交换反应温度33℃;树脂填充量0.1762g;样品为NaOH溶液(Na~+浓度10mg/L),流速0.92mL/min;再生剂(HCl)浓度4%,流速1.25mL/min,用量40mL.本方法实现了一次测定同时获得WACR平衡交换容量(E_q)、全交换容量(E_t)和利用率(η)等多个指标.与GB法对比,二者相关性好(r=0.9904).     

质子交换膜燃料电池材料

质子交换膜燃料电池是最接近商业化的一种燃料电池,最有希望作为未来电动汽车的发动机,近二十年取得了长足的发展.目前限制质子交换膜燃料电池进入商业化的最主要原因是成本和寿命两大问题,寻找和开发新型材料成为解决这两大问题、推进商业化进程的必然选择,也是质子交换膜燃料电池近些年来的研究重点和热点.本文对构成质子交换膜燃料电池的...     

熔融共混加工过程中的酰胺交换反应

聚酰胺(Polyamide, PA)是应用最广的工程塑料之一。不同类型聚酰胺的加工及耐热吸湿等诸多性能存在较大差异，为进一步改善聚酰胺材料的综合性能并降低成本，熔融共混是最基本的方法。熔融共混时受高温和机械力场的影响，酰胺键打开重新排列发生交换反应，均聚物转化为共聚物，导致高分子链结构、结晶结构和更高层次的聚集态结构发生变化，材料强度、模量、韧性、热变形、吸湿等性能发生变化，从而满足特定应用场景需求。本文对熔融共混加工过程酰胺交换反应的研究进行归纳总结，介绍了酰胺交换反应的分析表征手段、具体的研究体系以及促进和抑制交换反应的方法。此外，对聚酰胺与聚酯、聚氨酯等其他高分子材料的交换反应也简要对比讨论。最后对利用酰胺交换反应及动态化学原理设计和制备高分子材料进行展望分析。     

基于阳离子交换基团的阴离子交换膜研究进展

近年来,阴离子交换膜燃料电池的发展受到了广泛关注。 开发具有碱稳定性能优异、电导率高的阴离子交换膜材料成为了研究的热点。 阴离子交换膜(AEM)主要由聚合物骨架和阳离子基团组成,除了聚合物骨架结构,离子交换基团是影响膜碱稳定性和电导率的重要因素,因此,设计离子基团是提高膜性能的重要手段之一。 本文综述了近年来功能基团分别为季铵、胍基、咪唑鎓盐、季鏻、金属配合物、N-螺环季铵盐、哌啶和吡咯等阳离子交换基团的AEM的研究进展,其中包括不同种类阳离子交换基团的AEM的结构,碱稳定性能和OH^-电导率,同时对于含有阳离子交换基团的AEM的结构设计进行了分析和展望。     

氧化锆及铈-锆复合氧化物的阴离子交换和配体交换色谱性能

高效液相色谱法;氧化锆及铈-锆复合氧化物的阴离子交换和配体交换色谱性能     

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.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。