Irreversible and reversible phase transitions of alkyl monolayers. Gas chromatographic evidence of polar solvent influence on the adsorbing properties of the layer

Summary Further to Gilpin's observations in liquid chromatography of the irreversible transformation of alkyl grafts, following the replacement of an organic mobile phase by an aqueous one, we describe some gas chromatographic experiments which lead to similar (log V_s, I/T) plots, as a consequence of the same solvent release process.We use paraffin films on siliceous supports or hydroxylated liquid substrates or C₂₂-alkyl bonded silica. These experiments demonstrate that this irreversible transition and the melting-like reversible transition are completely different phenomena. They confirm the existence of at least three kinds of monomeric alkyl films.     

寒热中药微量元素的比较与分析

对28种温热中药及28种寒凉中药所测定的12种微量及常量元素进行了比较分析，发现温热药中Mn、Cu、Na、K含量显著高于寒凉药，而寒凉药中的Ca含量显著高于温热药，结果提示微量元素及常量元素含量的差异是中药寒凉温热性质的物质基础之一。     

钛-锆氧化物复合填料的正相色谱性能评价

采用油乳法制备了钛锆复合氧化物并系统评价了该填料的正相色谱性能。研究结果表明，该填料对碱性化合物有良好的分离选择性，峰形对称；但对酚类化合物强烈保留，峰形较差；中性化合物和碱性化合物的色谱行为均符合Snyder吸附顶替模型。     

高分子量的枝状聚硅烷的合成与表征

根据硅氢加成反应机理设计了“顺点滴式”工艺 ,高效、低耗地合成了甲基苯乙基二氯硅烷和甲基正己基二氯硅烷 .根据Wurtz还原偶联反应原理 ,采用“预聚”和“混聚”两种工艺分别合成枝状共聚硅烷 ,发现运用“预聚”工艺可以合成分子量很高的枝状聚硅烷 .     

Energy transfer rates and impact sensitivities of two classes nitramine explosives molecules

Some explosives are stable molecules with large energy barriers to chemical reaction, and in shock or impact initiation, a sizable amount of phonon energy must be converted to the molecular internal higher vibrations by multiphonon up pumping. To investigate the relationship between impact sensitivities and energy transfer rates, the number of doorway modes of explosive molecules is estimated by a simple theory in which the rate is proportional to the number of normal mode vibrations. We evaluated frequencies of normal mode vibrations of 13 explosive molecules which are CHNO nitramine-contained and have not been analyzed previously. The number of doorway modes in the regions of 200–700 cm⁻¹ was evaluated by the direct counting method. For more clear investigation of the relationship we have classified these 13 nitramine explosive molecules, by the number of nitramine group they contained, into two groups. There are eight molecules that contained one nitramine group and five molecules that contained poly-nitramine groups. It is found that the number of doorway modes shows a linearly correlation to the impact sensitivities derived from drop hammer tests. This result is in agreement with that of several previous works. Besides, it is also noted in our study that in those nitramine explosives molecules with similar molecular structure (similar number nitramine group they contained) and similar molecular weight, the correlation between the sensitivity and the number of doorway modes is higher. We found that the vibrational frequency of ω corresponds to nitro group motions of every molecule is contributed to the number of doorway modes in the regions of 200–700 cm⁻¹.     

笼形聚偕胺肟树脂的研究—酚处理对树脂吸附贵金属性能的影响

研究了笼形聚偕胺肟树脂（CAO）和酸式（ACAO）及碱式（BCAO）树脂对于苯酚、对-氨基酚、对-硝基酚、对-甲氨基酚和对-苯二酚的吸附和吸留作用，测定了酚处理树脂的中和当量。它反映了笼形树脂吸留外来物的特性。酚处理树脂有效地吸附Ag 、AuCl4－、PtCl62-、PdCl42-和IrCl62-等贵金属离子，吸附方式似乎与溶液的pH值有关。SEM观察表明，Ag 、Au－Cl4-和IrCl62-离子在吸附过程中被还原为零价态，在树脂表面生成形态各异的结晶。     

中国正常人体内元素含量的检测研究

开展正常人体内元素含量的检测研究具有重要生物学意义，不仅可充实我国正常成年人脏器组织元素含量值的基础医学数据，为研究人体内微量元素与健康的关系提供科学依据、也为辐射防护领域内放射性核素的剂量估算提供重要参数。本文从以下五个方面进行了论述：（）体内元素含量检测研究的目的、意义及其概况；（2）元素含量检测的重要性及其历史沿革；（3）元素的检测方法及质量控制；（4）人体内脏器组织元素含量的数值；（5）与国外资料相比较。本文着重介绍了我国100例正常成年人20个脏器组织（包括胃、小肠、大肠、心、肝、脾、肺、肾、…     

LIMS系统在实验室规范运作中的应用

简要介绍了LIMS系统及其对规范实验室运作发挥的作用和在应用中的具体情况。     

Normal coordinate analysis of MSiH3 moieties in transition metal complexes and comparison to results obtained for silyl halides

In order to examine the influence of the transition metal on the metal-silyl fragment MSiH₃ and the metal-silicon bond, polarized Raman spectra of the complexes (C₅R₅)(CO)₂FeSiH₃ R = H (Cp) (1a), Me (Cp^*) (1b)], (C₅H₅)(CO)(PPh₃)FeSiH₃ (1c), (C₅Me₅)(CO)₂RuSiH₃ (2), (C₅R₅)(CO)₂(PMc₃)MoSiH₃ [R = H (3a), Me (3b)], and (C₅R₅)(CO)₂(PMe₃)WSiH₃ [R = H(4a), Me (4b)] have been recorded. The spectral data have been evaluated and interpreted on the basis of a normal coordinate analysis of the MSiH₃ core and the derived force constants and potential energy distributions were compared to results obtained for analogous halogen derivatives in the series XSiH₃ [X = Br (5), I (6)].     

Darstellung,Kristallstruktur und Normalkoordinatenanalyse der bindungsisomeren Pentachlororhodanoosmate(IV)

Preparation, Crystal Structure and Normal Coordinate Analysis of Linkage Isomeric Pentachlororhodanoosmates(IV) By treatment of [OsCl₅I]^2? with (SCN)₂ in dichloromethane the linkage isomers [OsCl₅(NCS)]^2? and [OsCl₅(SCN)]^2? are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on single crystals of (Ph₄As)₂[OsCl₅(NCS)] (monoclinic, space group P2₁/a, a = 18.872(2), b = 11.6024(2), c = 22.786(1), β = 109.057(1)°, Z = 4) and (Ph₄As)₂[OsCl₅(SCN)] (monoclinic, space group P2₁/a, a = 19.057(2), b = 11.306(2), c = 22.612(1), β = 106.64(2)°, Z = 4) reveals the complete ordering of the complex anions. The thiocyanate group is located above one of the Cl ligands of the equatorial plane with the Os? N? C angle of 166.1° for N bonding and the Os? S? C angle of 109.9° for S bonding. The IR and Raman spectra of both linkage isomers known from literature are assigned by normal coordinate analysis based on the general valence force field using the molecular parameters of the X-ray determination. The valence force constants are f_d(OsN) = 1,81 and f_d(OsS) = 1,32 mdyn/Å. Taking into account increments of the trans influence a good adjustment between observed and calculated frequencies is achieved.