石油亚砜萃取色谱法分离钪和稀土

提出以石油亚砜为固定相,硫氰酸铵和盐酸为流动相的萃取色谱法分离钪和稀土。研究了影响钪和稀土分离的条件,本体系中钪和钕的分离系数达到1.3×10~4。该方法可用于混合稀土中小量钪的分离,提取和分析。     

7-碘-8-羟基喹啉-5-磺酸-溴化十六烷基三甲铵荧光测定微量钪的研究

用8-羟基喹啉衍生物测定钪的荧光法研究已有报道。本文研究了不同表面活性剂对钪-7-碘-8-羟基喹啉-5-磺酸(H_2QSI)反应的增敏作用,其中以溴化十六烷基三甲铵(CTMAB)增敏效果最好,与相应二元体系相比,灵敏度可提高十二倍,检出钪的最低浓度为2×10~(-8)M。同时确定了配合物最佳形成条件和配合物的组成,检查了共存离子的影响,拟定了混合稀土中微量钪的测定方法。实验部分 (一)主要试剂与仪器钪标准贮存液为3.0×10~(-2)M的2N盐酸溶液,用时按需稀释;3×10~(-4)M H_2QSI水溶液;     

络天青S-溴化十六烷基吡啶吸光光度法测定混合稀土中钪的研究

研究了钪-络天青S(CAS)-溴化十六烷基吡啶(CPB)三元体系的光度特性,确定了测定混合稀土中钪的最佳条件,探讨了表面活性剂的增敏机理,提出了一种灵敏度高、选择性好的测钪方法。其络合物在λ_(max)=630nm处的ε为1.01×10~5,灵敏度是相应二元体系的四倍。在0～6.5/25ml范围符合比耳定律。最低检出限1.4ng·ml~(-1)。应用于合成稀土样品中钪的测定,结果满意。     

α型钪-间硝基偶氮氯膦-氯化十四烷基吡啶显色体系的研究及其应用

本文研究了钪-间硝基偶氮氯膦-氯化十四烷基吡啶(Sc-CPAmN-TPC)显色体系的光度特性,并确定了在该体系中以α型钪络合物进行测定的最佳条件。络合物最大吸收位于677 nm,显色酸度为0.3mol/L硝酸,CPAmN浓度为3×10~3％。TPC浓度为0.05％,摩尔吸光系数为4.5×10~4。该体系与相应的二元体系相比,灵敏度和选择性均有较大幅度的提高,据此提出了测定钪的新方法。用于铁基和铜基合金合成试样中痕量钪的测定。结果满意。其标准偏差和变异系数分别为0.10和0.14与3.1％和2.8％。     

8-羟基喹啉-5-磺酸-溴化十六烷基三甲铵荧光法测定微量钪的研究

荧光分析中应用表面活性剂的报导不多,但已可看出,加入适宜的表面活性剂可提高方法的灵敏度和选择性。为研究阳离子表面活性剂的增敏作用,我们选择了钪-8-羟基喹啉-5-磺酸-溴化十六烷基三甲铵(CTMAB)体系进行了试验,确定了三元络合物的组成,拟定了混合稀土中微量钪的测定方法。灵敏度达5×10~(-8)M,这在测定钪的荧光方法中是比较高的。     

白云鄂博选铌尾矿浸出液制备高纯Sc_2O_3的工艺研究

白云鄂博矿经过选稀土、萤石和铌的工艺流程后,近400×10~(-6)的钪富集到选铌尾矿中。选铌尾矿的HCl浸出液中钪含量非常低,其他杂质含量高,采用除杂-富集-提纯-沉淀-焙烧工艺提取高纯Sc_2O_3。首先采用TBP萃取先将铁去除,铁的去除率可达97%以上,然后采用P507对钪进行萃取富集,萃取率在99%以上, NaOH溶液反萃得到钪富集物, HCl溶解后得到ScCl_3溶液,再用P350进一步萃取提纯,得到99.99%的ScCl_3溶液,草酸沉淀去除非稀土杂质,经过焙烧最终得到纯度为99.99%的Sc_2O_3。     

电感耦合等离子体原子发射光谱法测定高纯氧化钪中痕量铁

<正>钪作为稀土元素,具有独特的物理化学性质,如钪元素加到铝合金中,可以显著提高合金的再结晶温度,强烈抑制沿晶断裂倾向,提高合金强度、塑性和断裂韧性~([1-2])。近年来,随着新材料技术的迅猛发展,氧化钪(Sc_2O_3)更是广泛应用于固体氧化物燃料电池(SOFCs)~([3])、新一代激光晶体~([4])、大功率金属卤素灯、高能辐射用核能屏蔽、特种陶瓷等领域。但氧化钪中含有的杂质元素会导致这些材料性能极大下     

钪-茜素S络合物吸附波

姚修仁等发现,在氯化铵、铜铁试剂、二苯胍底液中,钪在单扫示波极谱上有灵敏的络合物吸附波。但钍、锆、铀及稀土等干扰严重。李南强等研究了钆-茜素S的络合物吸附波,由于介质为弱碱性,故所有稀土元素都能产生络合物吸附波。我们发现,在茜素S、邻苯二甲酸氢钾和氨基乙酸底液(pH3.6—4.1)中,钪在单扫示波极谱上有良好的络合物吸附波。用钛铁试剂可消除少量铁、稀土等的干扰,检测限达1×10~(-7)M,钪的浓度在2×10~(-7)—     

π-烯丙基稀土配合物的合成、结构及其催化烯烃聚合反应机理的研究——Ⅱ.LiY(π-C_3H_5)_4·2.5D催化异戊二烯聚合反应机理的研究

<正> 在稀土配位共轭双烯烃聚合反应机理的研究中,一般认为按π-烯丙基机理进行,但迄今为止尚缺乏足够的实验证据。我们曾用~1H-NMR、一维~(13)C-NMR和二维~(13)C-NMR系统地研究了(CF_3COO)_2LnCl·EtoH-(i-Bu)_2AIH-共轭双烯烃(Ln=La、Pr、Nd、Sm、Tb、Ho、Sc和Y)均相聚合体系的聚合机理,提出了η~4-共轭双烯(顺式-反式-)和η~3-烯丙基(同式-对式-)机理。但由于广烯丙基稀土配合物稳定性差,难于合成,加之聚合体系中很难直接分离出π-烯丙基稀土配合物活性体,为此,至今尚未能用模型π-烯丙基稀土配合物对上述机理进行研究。我们已合成一系列π-烯丙基稀土配合物LiLn     

OP存在下铬天青S-CPC分光光度法测定微量钪

近年来,各种表面活性剂作为铬天青S与钪显色反应的增感剂,已有不少报导。本文同时应用聚乙二醇辛基苯基醚(OP)和氯代十六烷基吡啶(CPC),大大地提高了铬天青S光度法测定钪的灵敏度。实验表明,采用OP-CPC比单独的OP或CPC增感作用显著,在pH为5.1-6.5的Sc-CAS-OP-CPC显色体系中,络合物的最大吸收峰位于612nm,ε_(612)=1.55×10~5。钪浓度在0-10微克/25毫升范围内符合比尔定律。在OP存在下,络合物的组成比为Sc∶CAS∶CPC=1∶2∶2。考察了数十种共存离子的影响,唯Be~(2-)、A1~(3-)、F、PO_4~3等严重干扰,但以PMBP-苯萃取分离后,可用于微量钪的测定。     

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。