电喷雾串联质谱法鉴定桔梗皂苷D

改进了桔梗皂苷D的提取、分离及鉴定方法 .首次利用大孔树脂脱糖脱色及薄层硅胶作色谱系介质 ,并首次利用电喷雾质谱对目标化合物进行跟踪分析 ,使高纯度的目标化合物的分离和鉴定工作得以简化

Synthesis and crystal structure of a novel amino-acid-containing polyoxometalate: K-6[Cu (Ala)(2) (H2O)(2)](2)[ CU4 (H2O)(2) (AsW9O34)(2)] center dot 16H(2)O

The novel amino-acid-containing polyoxometalate Ka(6) [Cu(Ala)(2) (H2O)(2)](2) [Cu-4 (H2O)(2) . (AsW9O34)(2)] . 16H(2)O was synthesized from the reaction of K-10[Cu-4(H2O)(2)(AsW9O34)(2)] . 20H(2)O with beta -alanine, Its structure has been determined by single crystal X-ray diffraction. It crystallizes in the triclinic space group P (1) over bar, with a=1. 196 3(2) nm, b=1. 536 5(3) nm, c=1. 591 4(3) nm, alpha =93. 97(3)degrees, beta= 110. 88(3)degrees, gamma =101. 07(3)degrees, V=2. 651 8(9) nm(3) and Z=1. Least-squares refinement of the structure leads to R and R-w factors of 0. 067 3 and 0. 162 8, respectively. An unusual structural feature of the compound is that the polyanion [Cu-4(H2O)(2) (AsW9O34)](10-) is linked with the amino-acid complex of Cu2+ by a mu -oxygen atom.

稀土基汽车尾气催化剂的催化活性研究

利用浸渍法制备了一系列含Ce La稀土助剂改性的Pt Rh三效催化剂 ,采用各种表征手段和高温抗硫水热老化实验 ,考察了Ce La稀土对Al2 O3 载体的热稳定性和催化剂活性的影响 .研究结果表明 ,稀土La2 O3 的添加主要改善了载体Al2 O3 的高温高比表面性能 ;而CeO2 的引入则明显地提高了CO和NO的催化转化活性 ,但对HC的转化几乎无影响 ,也促进了催化剂的抗硫水热老化性能 ,并且显著地拓宽了催化剂的三效窗口 .这主要归因于CeO2的添加 ,它改善了催化剂上CO ,HC和NO间的相互作用以及CeO2 所特有的储氧功能

Synthesis and properties of optically active poly(amide-imide)s containing axially dissymmetric 1,1 '-binaphthyl moieties

Novel optically active aromatic poly(amide-imide)s (PAIs) containing 1,1'-binaphthyl-2,2'-diyl units in the main chain were prepared by polycondensation reactions of newly synthesized dianhydride, 2,2'-bis(3,4-dicarboxylzenzamido)-1,1'-binaphthyl dianhydride[(S)-BN-DADA and (+/-)-BNDADA], with diamines, The properties of the resulted PAIs were fully characterized by a combination of investigations on inherent viscosity, thermal properties(DSC and TGA), specific rotation, CD and UV-Vis absorbance. These PAIs showed good solubilities, thermal properties and optical stabilities. Interesting UV-Vis absorption behavior of films casted from these PAIs was observed and analyzed.

含联萘基团旋光性聚酰亚胺的合成与性质

从1,1'-联萘-2,2'-二胺出发，合成了旋光性二酐单体及相应的外消旋体：(S)-,(R)－和(±)-2,2'-(3,3',4,4'-四酸二酐)二苯甲酰胺-1,1'-联萘．二酐与二胺单体通过溶液缩聚反应制得一系列旋光性聚酰胺酰亚胺．聚合物具有较好的热稳定性、旋光稳定性、良好的溶解性以及独特的光学性质

SnO_2纳米粒子膜的性质和结构研究

用胶体化学法制得的SnO2水溶胶在其与空气的界面上能自发形成一层固态膜，将陈化不同时间的界面膜转移出来，采用紫外－可见光谱、X光电子能谱、椭圆偏振、TEM以及AFM等手段进行了表征。结果发现：界面膜有一个从无到有、达到稳定的过程，稳定时膜厚约为20nm；采取垂直方式转移出来的膜质量较好，致密、粒子分布均匀、团聚程度小；膜中SnO2纳米粒子是非化学计量比的，存在大量氧空位，随膜在空气中放置时间的增长，氧空位逐渐减少。

(Z)-1[2-(苯基二溴化锡基)乙烯基]-1-环己醇的合成及晶体结构

报道了标题化合物〔C14H18Br2OSn〕的合成及晶体结构。该晶体属于单斜晶系，空间点群为P21/c，晶胞参数a=11.711(2)，b=9．114（2），c=16．864（3）A，β=102.94（1）°，V=1604.55（0）A3，Mr=480．78，Z=4，Dc=1．99g／cm3，u=65．20cm－1，F（000）=919，R=0．050，Rw=0．050．晶体结构由直接法解出。标题化合物分子中的锡原子被配体的2个碳、2个溴和1个氧原子配位，配位原子呈畸变的三角双锥构型，环已基为椅式构象，五员杂环为信封构象。

Syntheses of indenyl lanthanide derivatives and the molecular structures of [(C9H7)(2)PrCl(THF)](2) and [(C9H7)(3)La(THF)]

The reaction of anhydrous PrCl3 with Na(C9H7) in 1.2 mole ratio in THF gives [(C9H7)(2)PrCl(THF)](2)1. 1 crystallized in monoclinic system, space group P2(1)/c with a = 7.808(2), b = 17.796(6), c = 14.070(4) Angstrom, beta = 93.97(2)degrees, V= 1950.3(9) Angstrom(3), Dcalcd = 1.63 g/cm(3) and Z = 2. Each Pr ion is surrounded by two indenyl, two Cl and one THF in a roughly trigonal bipyramid arrangement with average Pr-C(ring) and Pr-Cl distances of 2.81 and 2.84 Angstrom. The reaction of LaCl3 with Na(C9H7) in 1:3 mole ratio gives (C9H7)(3)LaTHF 2, which crystallizes in the monoclinic space group P2(1)/a with unit cell constants a = 21.871(8), b = 10.585(3), c = 23.652(7) Angstrom,beta = 114.62(2)degrees, V = 4977.9 Angstrom(3) and Z = 8. (C) 1997 Elsevier Science S.A.

Synthesis and properties of optically active aromatic polyimides derived from optically pure 1,1'-bi-2-naphthol

A series of new optically active aromatic polyimides containing axially dissymmetric 1,1'-binaphthalene-2,2-diyl units were prepared from optically pure (R)-(+)-or (S)-(-)-2,2'-bis(3,4-dicarboxyphenoxy)-1,1'-binaphthalene dianhydrides and various aromatic diamines via a conventional two-step procedure that included ring-opening polycondensation and chemical cyclodehydration. The optically pure isomer of dianhydride was prepared by a nucleophilic substitution of optically pure (R)-(+)or (S)-(-)1,1'-bi-2-naphthol with 4-nitrophthalonitrile in aprotic polar solvent and subsequent hydrolysis of the resultant tetranitrile derivatives, followed by the dehydration of the corresponding tetracarboxylic acids to obtain the dianhydrides. These polymers were readily soluble in common organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and m-cresol, etc., and have glass transition temperatures of 251-296 degrees C, and 5% weight loss occurs not lower than 480 degrees C. The specific rotations of the optically active polyimides ranged from +196 degrees to +263 degrees, and the optical stability and chiroptical properties of them were also studied. (C) 1997 John Wiley & Sons, Inc.

Cure processing modeling and cure cycle simulation of epoxy-terminated poly(phenylene ether ketone) .2. Chemorheological modeling

Chemorheology and corresponding models for an epoxy-terminated poly(phenylene ether ketone) (E-PEK) and 4,4'-diaminodiphenyl sulfone (DDS) system were investigated using a differential scanning calorimeter (DSC) and a cone-and-plate rheometer. For this system, the reported four-parameter chemorheological model and modified WLF chemorheological model can only be used in an isothermal or nonisothermal process, respectively. In order to predict the resin viscosity variation during a stepwise temperature cure cycle actually used, a new model based on the combination of the four-parameter model and the modified WLF model was developed. The combined model can predict the resin viscosity variation during a stepwise temperature cure cycle more accurately than the above two models. In order to simplify the establishment of this model, a new five-parameter chemorheological model was then developed. The parameters in this five-parameter model can be determined through very few rheology and DSC experiments. This model is practicable to describe the resin viscosity variation for isothermal, nonisothermal, or stepwise temperature cure cycles accurately. The five-parameter chemorheological model has also successfully been used in the E-PEK systems with two other curing agents, i.e., the diamine curing agent with the addition of a boron trifluride monoethylamine (BF3-MEA) accelerator and an anhydride curing agent (hexahydrophthalic acid anhydride). (C) 1997 John Wiley & Sons, Inc.

A preliminary study on chemistry of phenoxynaphthacenequinones

A preliminary study on the chemistry of 6-phenoxy-5,12-naphthacenesuinone derivatives was reported, It was found that the main product was 6-(N,N-dimethylamino)-5,12-naphthacenequinone when a reaction of 6-chloro-5,12-naphthacenequinone with 4-hydroxyazobenzenes in DMF was carried out under certain reaction conditions. When the reaction of 6-[4-(4-hydroxyphenyl)isopropyl)phenoxy]-5, 12-naphthacenequinone and epichlorohydrin was carried out in an acetone/DMF(V/V=2/1) mixed solvent and in the presence of K2CO3 and KI, a new phenoxynaphthacenequinone derivative,6,6'-[1-methylethylidenebis(4,1-phenyleneoxy)]bis(5,12-naphthacenequinone), was obtained.

KCl-LiCl共晶熔体中Nd~(3+)和Ho~(3+)的电化学行为

用循环伏安法和恒电流电解后的电位时间曲线法，研究了ＬｉＣｌＫＣｌ熔体中Ｎｄ３＋和Ｈｏ３＋在Ｍｏ电极上的电化学行为。结果表明，Ｎｄ３＋和Ｈｏ３＋在Ｍｏ电极上的还原都为一步３电子可逆过程。其扩散系数分别为：１１３×１０－６和２１４２×１０－５ｃｍ２·ｓ－１（４５０℃），４５０℃下Ｈｏ３＋／Ｈｏ电极对的标准氧化还原电位为２９８７Ｖ（ｖｓ·Ｃｌ／Ｃｌ－１），并讨论了实验值较理论值偏负的原因。

萃取色谱分离-原子发射光谱测定超高纯氧化铽和氧化镝中痕量稀土杂质

研究了２＿乙基己基膦酸单２＿乙基己酯萃取色谱分离＿原子发射光谱测定超高纯Ｔｂ４Ｏ７和Ｄｙ２Ｏ３中痕量稀土杂质，方法可用于纯度（质量分数ｗ）为９９９９９９％～９９９９９９９％Ｔｂ４Ｏ７和Ｄｙ２Ｏ３的分析。在铽和镝的样品中其它稀土杂质的回收率分别为７３％～１３３％和９５％～１２０％，６次测定平均值的相对标准偏差分别为５８％～２２％和７９％～２０％，分离周期为９ｈ和１２ｈ。

Cryoimmobilized enzyme for biosensor construction

A new immobilization material and an immobilization method for a glucose sensor with HEFc (hydroxyethylferrocene) as mediator is described. In the course of three months, the enzyme electrode shows almost no deterioration in its response characteristics. The response time is less than 30 s. The electrode has a wide linear range up to 10 mmol l(-1) with good repeatability. The kinetic parameters have also been calculated.

Luminescence of Pb2+ and energy transfer from Pb2+ to rare earth ions in silicate oxyapatites

The Pb2+ luminescence in a series of silicate oxyapatites Me(2)(Y, Gd)(8)(SiO4)(6)O-2, Me(4)Y(6)(SiO4)(6)O (Me = Mg: Ca, Sr) is reported and discussed in relation to the crystal structure. The maximum wavelengths of the excitation (S-1(0)-P-3(1)) and emission (P-3(1)-S-1(0)) bands of Pb2+ are independent of the Mc:Y ratio (2:8 or 4:6) but they have lower energies in MgY-oxyapatites than in CaY- and SrY-oxyapatites. The Stokes shift of Pb2+ luminescence amounts to 11 100 to 11 400 cm(-1): which does not depend strongly on the host composition. There exists a mutual energy transfer between Pb2+ and Gd3+ in Sr2Gd8(SiO4)(6)O-2. At last, the dependence of the energy transfer efficiency of Pb2+-Sm3+, Tb3+: Dy3+ in Sr-2(La: Gd)(8)(SiO4)(6)O-2 and Ca-2(Y, Gd)(8)(SiO4)(6)O-2 on their doping concentrations was studied in more detail.