2,6—双（1′—苯基—3′—甲基—5′—氧代—4′—甲酰吡唑）吡啶稀土配合物的合成

在乙醇－水溶液中合成了１４种２，６－双（１′－苯基－３′－甲基－５′－氧代－４′－甲酰吡啶）吡啶稀土配合物，元素分析确定其化学组成的ＲＥ２Ｌ３．ｎＨ２Ｏ并用紫外可见光谱、红外光谱，核磁共振谱，热分析，荧光光谱，摩尔电导等进行了表征。     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

Investigation on chiral capillary columns and their application in separation of enantiomers

Six chiral diamide stationary phases (CSPs), namely N-(3-carbobenzoxypropionyl)-L-Val-tert-butylamide (CSP-1), N-undecenoyl-L-Val-S-α-phenylethylamide (CSP-2), N-undecenoyl-L-Val-R-α-phenylethylamide (CSP-3), OV-225-L-Val-tert-butylamide (CSP-4), XE-60-L-Val-tert-butylamide (CSP-5) and polycyanoethyl vinyl siloxane-L-Val-tert-butylamide (CSP-6), were inves-tigated and CSP-6 was crosslinked within narrow bore (70 μm) fused silica capillary columns. Theseparation of amino acid enantiomers on this narrow bore column by gas chromatography (GC) isillustrated.     

液体端伯胺基聚丁二烯的制备

在烃类溶剂中,聚丁二烯基锂用2—3倍当量的N-乙酰氮丙啶处理后,继以水解、分离,从而得到液态端伯氨基聚丁二烯。产物的分子量(约为3000)和官能度(约为2)迟到预期结果,在聚丁二烯主链中,总1-4单元占90％以上,其中顺式构型约占三分之一。     

二乙基二硫代氨甲酸银体系流动注射法测定砷

本文设计了一种ＡｇＤＤＣ流动注射－分光光度法测定砷的系统。该系统采用自制的氢化物发生及吸装置，将液体流路和载气流路结合在一起。     

Aggregate manganese Schiff base moieties by terephthalate or acetate: dinuclear manganese and trinuclear mixed metal Mn2/Na complexes

A reaction system consisting of terephthalic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and salicylidene alkylimine resulted in dinuclear manganese complexes (salpn)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(H(2)O) (3), and (salen)(2)Mn(2)(mu-phth) (4), while the absence of NaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH(3)OH)(NO(3)) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H[Mn(2)Na(salpn)(2)(mu-OAc)(2)(H(2)O)(2)](OAc)(2) (6) was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ions were found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure. Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 was considered to stem from intermolecular magnetic coupling. (1)H NMR signals of phenolate ring and alkylene (or phenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3 to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidation states of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchange interaction between the Mn(III) sites was observed with J = 1.74 cm(-1). A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn(2)(III)/Mn(III)Mn(II), implying the intactness of the complex backbone in solution.     

In situ disorder-order transformation in synthetic gallosilicate zeolites with the NAT topology

Here, we report that synthetic gallosilicate molecular sieves with the NAT topology and Si/Ga ratios close to but slightly higher than 1.50 undergo an in situ transformation under their crystallization conditions. The materials have been studied ex situ by using powder X-ray diffraction, elemental and thermal analyses, and multinuclear MAS NMR. The transformation is characterized by a change in the distribution of Si and Ga of the NAT framework, from a quite (but not completely) disordered phase to a very highly (but not completely) ordered one, accompanied by a change from tetragonal to orthorhombic symmetry. During most of the solution-mediated transformation, no noticeable signs of fresh precipitation, phase segregation, or changes in the chemical composition are detected. Intermediate materials show variations in the degree of Si-Ga ordering and orthorhombic distortion and are not physical mixtures of the disordered and ordered phases. Ab initio calculations strongly suggest a preferential siting of Si in the tetrahedral sites involved in a smaller number of 4-rings in the NAT topology (i.e., the low multiplicity site). The cost of violations of Loewenstein's rule has also been calculated. For this topology and chemical composition the preferential siting and Loewenstein's rule drive together the system to the ordered configuration. A Monte Carlo sampling procedure affords a reasonable model for the initial, mainly disordered state, which fits well within the experimental disorder-order series.     

Determination of enterostatin in human cerebrospinal fluid by capillary electrophoresis with laser induced fluorescence detection

A capillary electrophoresis (CE) method with laser induced fluorescence (LIF) detection is described for quantification of enterostatin (Val-Pro-Asp-Pro-Arg), a pentapeptide involved in appetite regulation and insulin secretion. Enterostatin and two other pentapeptides belonging to the enterostatin family (i.e. Ala-Pro-Gly-Pro-Arg and Val-Pro-Gly-Pro-Arg) were well separated from each other. The peptides were fluorescently tagged with naphthalene-2,3- dicarboxaldehyde (NDA) and separated by micellar electrokinetic chromatography (MEKC) in the presence of methanol as an organic modifier. Coupled with LIF detection, the method had a detection limit of 4.8 x 10(-6) M for enterostatin. The relative standard deviation was to be 4.0% from five determinations of enterostatin at 37.2 microM in a human cerebrospinal fluid (CSF) sample. Twenty-three human CSF samples were analyzed. The level of enterostatin ranged from 24 microM to 51 microM with a mean (+/- SEM) value of 41.7 +/- 2.0 microM.     

BIOCHEMICAL ISOLATION AND SPECTROSCOPIC CHARACTERIZATION OF POSSIBLE PHOTORECEPTOR PIGMENTS FOR PHOTOTAXIS IN A FRESHWATER Peridinium

Photoreceptor pigments have been isolated biochemically from the freshwater dinoflagellate Peridinium gatunense, and characterized spectroscopically. At least four different chromoproteins can be detected in the crude extract and the membrane fraction isolated from the cells absorbing at 580, 638, 667 and 710 nm, which correspond with the maxima in the action spectrum for phototaxis in this organism. Light energy absorbed by shorter wavelength pigments is emitted as fluorescence at wavelengths which are absorbed by pigments with maxima at longer wavelengths. Protein separation on a MonoQ anion exchanger column using fast liquid chromatography resulted in a non-bound fraction and four bound fractions eluted by an NaCI gradient, which differed in their pigment composition.     

β-环糊精诱导室温燐光法测定痕量苊的研究——以环氧溴丙烷作重原子微扰剂

环糊精诱导室温燐光法(CD-RTP)中的重原子微扰剂,文献报道仅限于1,2-二溴乙烷(DBE)和1,2-二溴丙烷(DBP)。本文首次发现了一种新的微扰剂——环氧溴丙烷(EBH)应用于β-CD-RTP 法测定痕量苊。详细比较了 EBH 和 DBP 的重原子效应,结果表明,二者性能类似,而 EBH 较 DBP 的实验条件宽容。