Cu(Ⅱ)自旋探针法研究温度敏感性水凝胶的相行为

本文采用Cu(Ⅱ)自旋探针法研究了N- 取代基丙烯酰胺水凝胶在不同温度时的ESR谱,发现不同的温度敏感性水凝胶.其Cu(Ⅱ)探针的ESR各向异性谱的变化也不同.这主要是由于取代基与Cu(Ⅱ)的相互作用不同所致.对于具有LCST相行为的NNPA 和NIPA水凝胶,当温度达到并超过其相转变温度时,即可测得其Cu(Ⅱ)自旋探针各向异性的ESR倒置谱,这种倒置谱是由于凝胶相变后,网格塌陷,网络缠裹水化Cu(Ⅱ)离子的结果.运用Cu(Ⅱ)自旋探针研究凝胶的相结构及其微观相行为是一种可行的方法     

固相萃取-离子迁移谱法快速筛查祛痘类化妆品中14种抗菌药物

目前,主动性的现场稽查已成为市场监管的发展趋势,这需要在现场快速有效地筛查大量产品,评估是否含有非法添加化学药物,对有嫌疑的样品及时封存,再送至实验室进一步检验。离子迁移谱技术是近年来发展起来的快筛技术之一。实验采用固相萃取-离子迁移谱技术,建立了祛痘类化妆品中14种抗菌药物的快速筛查方法。对离子迁移谱检测条件、样品提取条件、固相萃取净化条件(固相萃取柱、淋洗液种类、洗脱液种类及体积)进行了详细考察与优化。最终使用80%(体积分数)乙腈水溶液(含0.2%(质量分数)三氯乙酸)作为样品提取溶液,提取后上样于活化后的弱阳离子交换柱(Oasis^® MCX固相萃取柱), 3.0 mL甲醇淋洗,1.0 mL 2%氨水甲醇洗脱,洗脱液直接进离子迁移谱检测。14种抗菌药物的迁移时间在11~17 ms之间,检出限为0.2~1.2 μg/g。同时,由于离子迁移谱法线性范围较窄,不能准确定量,建立了高效液色谱(HPLC)定量方法,用于固相萃取前处理步骤的优化和阳性样品的验证。25批化妆品样品中,筛查出1批阳性样品,与HPLC检测结果相符。该方法快速、简便、高效,显著降低了祛痘类化妆品基质对离子迁移谱检测14种抗菌药物的干扰,提高了检测灵敏度,有效降低了假阳性和假阴性的发生,可用于化妆品现场快速筛查,同时也扩大了离子迁移谱在化妆品等复杂基质中非法添加化学药物检测的应用范围。     

Nd—Fe—Co—B永磁合金的磁性和穆斯堡尔效应的研究

本文研究了Nd_(17)(Fe_(1-x)Co_x)_(75)B_8(x=0,0.05,0.1,0.2和0.3)永磁合金的磁性和穆斯堡尔谱。得到了合金中四方相、富B相和富Nd相的穆斯堡尔参数——同质异能位移、电四极分裂和超精细场随Co含量的变化关系;根据合金中各含铁物相及四方相中各铁晶位的穆斯堡尔亚谱面积定量估算了各物相的体积分数和铁、钴原子在四方相各晶位的分布情况;由四方相穆斯堡尔谱第2与第3条谱线的强度比计算了合金的磁矩取向角。并从上述穆斯堡尔谱中获得的微观结构方面的结果讨论了合金的剩磁、矫顽力和居里温度。     

[Fe(L)3](ClO4)3(L=bpy,phen)与Na2S2O3在室温下的固相氧化还原反应

本文研究室温下[Fe(bpy)3](ClO4)3.3H2O和[Fe(phen)3](ClO4)3.H2O分别与Na2S2O3.5H2O发生的固-固相氧化还原反应。用Mossbauer谱、XRD、IR、UV漫反射谱、元素分析、TG-DTA和磁化率测定等手段表征了反应24h后的固相产物,报道了[Fe(bpy)3](ClO4)2的结晶学数据。结果表明, 室温下反应速度快, 反应进行完全。     

MZr2（AsO4）3（M=Na,K,Rb,Cs）的水热合成与结构表征

用水热晶化法合成了MZr_2(ASO_4)_3(M=Na,K,Rb,Cs)系列化合物。研究了反应物浓度、配比及不同砷源等水热晶化条件对产物物相的影响。用XRD、IR和Raman光谱对产物进行了表征。4种晶体的振动光谱由钠到铯呈现出规律性变化。     

双苯甲酰胺冠醚固定相的合成及毛细管柱气相色谱性能的研究

合成了一种新型的双苯甲酰胺冠醚固定相:(1S,2S)-1-(对苯甲酰胺基)苯基-2-苯甲酰胺基-16-冠-5,其结构经红外光谱、核磁共振、质谱及元素分析数据证实。考察了这种固定相的柱效、热稳定性、极性及选择性等色谱特性。该类固定相对极性位置异构体分离效果良好。由于冠醚上引入苯甲酰胺取代基,因而对苯胺类及不经衍生化的碱性化合物能特殊选择性地分离。     

新型高冲击韧性环氧乙烯基酯树脂的合成和表征

通过引入柔性环氧封端聚醚(ETPE)单体, 报道了一种温和且高效制备新型高冲击韧性的乙烯基酯树脂(EVER-2)的方法。 用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(¹H NMR)和碳谱(¹³C NMR)等技术手段对其结构进行了表征, 并对其拉伸强度、弯曲强度和冲击韧性等力学性能和热变形温度进行了测试。 结果表明, 只需少量的ETPE参与反应(约占树脂总质量的7.9%), EVER-2固化产物就具有很高的冲击韧性。 其SEM的冲击断面形貌表明, 新型高冲击韧性乙烯基酯树脂为均相结构, 其与玻璃纤维有很好的粘结能力。 提出了EVER-2及其与玻璃纤维复合材料 EVERL-2可能的增韧机理。     

烯醛一步法合成异戊二烯的60—100℃油相分析

用精密分馏、制备色谱、气液色谱、物理常数(比重、折光率、分子量和元素分析)、紫外光谱、红外光谱和核磁共振谱等方法定性鉴定了烯醛一步法制异戊二烯油相样品(60—100℃馏分)中13个烃类单体和10个含氧化合物单体以及族分析出7个烯烃和3个含氧化合物。建立了蒸馏、液固色谱和气液色谱相结合的常规定量分析60—100℃馏分油相样品的方法。     

聚甲基丙烯酸正丁酯的核磁共振异核相关二维谱

<正> 核磁共振二维谱是研究高聚物分子结构的有力工具.有时一张谱图,就能得到高聚物序列结构或共聚物构型的直接证据.对高聚物结构分析有重要意义.自1983年Brown首次报道聚氯乙烯的二维J谱以来.美国Macromolecules等杂志竟相报道各种聚合物的二维谱图.目前已经报道过的聚合物核磁共振二维谱有二维J谱、~(19)F-~1H异核相关谱、~(13)C-~1H异核相关谱、~1H COSY谱、~(19)F COSY谱、NOESY     

液相色谱梯度洗脱中的谱带压缩效应

谱带压缩效应是梯度洗脱区别于等度洗脱的重要特征。经典的范德姆特(van Deemter)理论塔板高度方程基于等度洗脱推导得到,因此不能对谱带压缩效应进行描述。在梯度洗脱中,保留因子(k)会随流动相组成(φ)的改变而发生变化,这就使得对梯度洗脱机理的研究要比等度洗脱复杂许多。该文对近10年来谱带压缩效应的研究进展,特别是溶剂强度模型(即描述ln k与φ关系的数学表达式)的非线性特征对谱带压缩因子(G)的影响进行了述评,指出为了更好地认识谱带压缩效应需要将这种非线性因素考虑在内。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.     

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.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

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。