缺Zn症患儿微量元素水平的样本特征分析及其临床补Zn治疗的评价

测定了150例缺Zn症患儿及健康儿发样中的Zn、Ca、Mg及Fe四元素水平．采用主成分分析法．将高维空间中的样本点映射到低维空间中来观察，研究其样本特征，评价临床补Zn治疗措施．结果瑶明：缺Zn症患儿体内缺Zn是病理的主要方面，但往往同时伴有其它微量元素水平偏低现象，临床缺Zn症状的表现可能为多种元素综合效应的反映．因此临床治疗不能单纯考虑朴Zn，还应结合患儿体内其他元素水平的具体情况，考虑其他元素的补给．治疗才能奏效显著．     

Early petroleum chemists and the beginnings of chromatography

Summary The activities of D. T. Day (1859–1915, J. E. Gilpin (1866–1924) and C. Engler (1842–1925) connected with the adsorptive filtration of petroleum oil samples are discussed. As indicated, their methodology can be considered as precursor of the chromatographic technique; however, it should not be envisaged as the beginnings of chromatography.     

Optical dephasing in a glass-like system: a photon echo study of pentacene in benzoic acid

Optical absorption and picosecond photon echo experiments are used to study the dephasing of pentacene in benzoic acid. It is shown that, while the absorption spectrum of pentacene is effected by proton transfer in the benzoic acid dimer, the dephasing is caused by elastic and inelastic phonon scattering processes.     

Allinger's gauche hydrogen hypothesis as tested by an alternative force field model

Allinger's hypothesis that gauche hydrogen, rather than gauche methyl interactions are mainly responsible for conformational equilibria was tested by molecular mechanics calculations using the Engler force field model. For the gauche-anti conformational energy of n-butane, effective cancellation among non-bonded in teractions involving the methyl groups results in the gauche hydrogen interactions across the central C-C bond as the single largest contribution to the energy difference. However, the contribution of this interaction is only one third of the 0.9 kcal difference. For 2,3-dimethylbutane, strain analysis of the gauche-anti conformational energy contributions reveals that geminal and gauche CH₃/CH₃ interactions dominate over the gauche hydrogen interaction Similar analyses for several monosubstituted cyclohexanes confirm that “across-the-ring” interactions. between axial substituents and syn -axial hydrogen atoms are still largely responsible for the instability of the axial relative to the equatorial conformer. In disagreement with Allinger's proposal, the “equatorial hydrogen effect” is found to contribute only a minor amount to the conformational energy difference. Allinger's hypothesis is concluded to be force field dependent, and not to have general validity.     

聚苯胺葡萄糖氧化酶电极的催化过程

用电化学方法固定在直径为0.5mm铂丝上的聚苯胺(PANI)葡萄糖(GOD)电极对葡萄糖有催化氧化作用.在0～-0.6V(vs.SCE)的电极范围内,在电极的循环伏安曲线上观察到与葡萄糖浓度有关的氧的还原峰和GOD还原态的氧化峰,用此GOD还原态的氧化峰电流可定量检测葡萄糖的浓度。本文提出在PANI电极上存在着酶反应氧化还原电荷直接传递的可能性。     

尼龙－1010的聚集态结构

用ＷＡＸＤ、ＤＳＣ、方差－范围函数．密度测量等方法，研究了经不同热处理的尼龙－１０１０的聚集态结构．发现退火处理更有利于尼龙－１０１０结晶的生成和稳定，且尼龙－１０１０的结晶，有一个最佳的热处理温度．在该温度附近，尼龙－１０１０的结晶度和微晶尺寸里最大值．     

The structure of crotofolin E,A novel tricyclic diterpene from Croton corylifolius

A novel and highly functionalized crotofolane diterpene, crotofolin E ($\text{4}$), has been isolated from Croton corylifolius L. (Euphorbiaceae) and its stereostructure determined from spectral and X-ray crystall crystallographic analyses.     

Friedlieb Ferdinand Runge (1794–1867): “Self-grown pictures” as precursors of paper chromatography

Summary F. F. Runge (1794–1867) made important contributions to the evolution of chemistry during the first part of the 19th century. In studying the possibility of carrying out reactions on filter paper, he produced pictures which strongly resemble present-day, circular paper chromatograms.On the occasion of the bicentenary of Runge's birth, this paper summarizes his life and activities, with particular emphasis on his chromatographic work, and on his philosophical interpretation of these pictures.     

Vibrational spectra and structure of trinitromethane

The vibrational spectrum of trinitromethane was interpreted in terms of the additive interatomic interaction model on the basis of experimental infrared and Raman spectra of HC(NO₂)₃, DC(NO₂)₃, HC(¹⁵NO₂)₃ and normal coordinate analysis. The frequency assignment results were used in discussing its structure. It was shown that the symmetry of trinitromethane is below C₃ in the liquid state.     

Automated development of analytical chemical methods : The determination of senun calcium by the cresolphthalein complexone method

The cresolphthalein complexone method for serum calcium determination was investigated by means of a modified Technicon Autoanalyzer II under computer control. Simplex optimization of reagent concentrations, followed by response-surface mapping in the region of the optimum produced a method yielding 8.5% greater calcium sensitivity and 15% lower baseline absorbance than the standard method, with comparable insensitivity to interferences, and only a very slight sacrifice in linearity; a comprehensive operational understanding of the chemical system was also obtained.     

An extraction—spectrophotometmc method for the determination of non-ionic surfactants

The surfactant is extracted into 1,2-dichlorobenzene as a neutral adduct with potassium tetrathiocyanatozincate(II), and zinc(II) in the extract is determined spectrophotometrically after addition of l-(2-pyridylazo)-2-naphthol and triethanolamine. With a 150-ml water sample, the limit of detection is 15 μg l^-1 (as Triton X-100). The method requires only one extraction and is applicable, without modification, to fresh, estuarine and sea-water samples.     

煤微观结构的X射线衍射原子分布函数分析

采用在非晶态结构研究中应用的Ｘ射线衍射原子分布函数法测试了四种不同煤化程度煤的碳原子平均径向分布，求出了碳原子间距、配位数、芳香度、聚合度和短程有序畴等结构信息，并与文献值进行了以比。结果表明，煤的碳原子间距及对应的配位数介于石墨和金刚石对应的数值之间，随着煤化程度的增加，芳香胺、聚合度和短程有序畴增大，煤的石墨化程度增加。     

Vibrational and high pressure conformational studies of 1,1,2-trichloroethane

The infrared spectra of 1,1,2-trichloroethane were recorded from 4000 to 50 cm^?1 in the vapour and liquid states. Additional spectra above 200 cm^?1 of the low temperature crystal and of two crystalline solids, prepared by compressing the sample in a diamond anvil cell, were obtained. Also, infrared spectra of the liquid and of the compound dissolved in CS₂ were recorded at increased pressures. Raman spectral data of the liquid (including polarization measurements) and of the low temperature crystal were obtained.The fundamental frequencies for each of the two conformers, C₁ and C_s, were assigned and the results checked by normal coordinate analysis. The same diagonal and off-diagonal force constants were employed for the two conformers and the force fields were derived by means of a least squares refinement, including data for chloroethane, 1,1-dichloroethane and various deuterated species. A standard deviation of 3 % was obtained in the final fit.From the changes in relative intensities for infrared bands belonging to the C₁ and C_s conformers with increasing pressure, the volume differences (ΔV¯between the conformers were determined in CS₂ solution and in the pure liquid.     

A decomposition procedure for the determination of arsenic in marine samples

The use of wet and dry ashing procedures to decompose marine biological tissues and to degrade organoarsenic compounds to inorganic arsenic for analysis by zinc-column arsine generation and atomic-absorption spectrophotometry was investigated. Wet ashing with nitric, sulphuric and perchloric acids (10:2:3 v/v) released the largest percentage of arsenic from fish tissue and quantitatively degraded methylated and other organoarsenic compounds to inorganic arsenic. The arsenic concentrations found when standard reference materials were ashed with this acid mixture were in agreement with the certified values.     

The vibrational force field of halogenated aromatic molecules: II. Out-of-plane vibrations of fluoroaromatics

A general quadratic force field is determined for the out-of-plane vibrations of florobenzenes. The force constants for the out-of-plane wagging of both CH and CF bonds decrease by about 10 % for each ortho fluorine substituent. No significant meta dependence could be detected. It is shown that the present field is in excellent accord with the chlorobenzene field of Scherer and with the benzene fields of Whiffen and of Kydd when due allowance is made for differences in coordinate definitions.     

Geometry optimised ab inttio calculations on 1,5- and 1,2-dicarba-closo-pentaborane (5)

Geometry optimised ab initio LCAO- MO-SCF calculations for the isomeric carboranes 1,5- and 1,2-dicarba-closo-pentaborane (5) are reported. The optimised geometry of the 1,5-isomer agrees with the experimental geometry and for this isomer greater thermo-dynamic stability is predicted. The framework bonding is due mainly to interactions between the apical atoms and those in the equatorial plane, while within this equatorial plane there is very weak bonding.     

Ab initio calculations of the equilibrium geometry of cis and trans methylglyoxal using the force method

Ab initio calculations of the equilibrium ground-state conformation of trans-methylglyoxal, CH₃COCHO, have been carried out using the gradient method and a 4-3 IG basis set. The results are compared with experiment and with a theoretical geometry computed using an STO-3G basis set, and the more usual stepwise optimization of the parameters. The molecular orbital energies, dipole moment and ionization energy are calulated. Calculations are also carried out on the cis-isomer and the barrier to cis-trans isomerization is obtained.     

电泳毛细管的改性及其在酶和单克隆抗体分离分析中的应用

用壁处理办法对高性能毛细管电泳的毛细管柱进行改性,在Bio-Rad HPE-100中用肽测得组分的平均柱效为200000/m,使用寿命在200次以上。对纤维素酶.尿酶等一系列的样品作了分离和测定,尿酶5次重复测定的相对标准偏差小于1％。在10min内分离并测定了由细胞瘤培养的实际样品中的抗乙肝抗体(HBsAG),反映迁移时间重复性的相对标准偏差为1.87％,并作出了相应校正曲线。