己二胺-12-钼磷酸电荷转移盐的光化学合成与晶体结构

采用光化学法合成一种有机-无机电荷转移盐，（HMDH2）[H2PMo12O40]·AA·3H2O·DMF（HMD = 1,6-己二胺，AA = 乙醛，DMF = N,N-二甲基甲酰胺）超分子化合物。用元素分析，IR，固体漫反射电子光谱，ESR进行了表征。X-射线四圆衍射测定其晶体结构属三斜晶系，空间群 Pī，Mr=2081.68，晶胞参数a = 14.092(3)，b =14.347(3)，c =14.358(3)?，α=75.10(3)，β=80.70(3)，γ=80.73(3)°,V=2746.6(10)?3，Z=2，Dc=2.517g/cm3，F(000)=1970，μ(MoKα)=2.766mm- 1，全矩阵最小二乘法修正至R=0.0832，wR=0.2638。标题化合物是由1个质子化的1,6-己二胺、12-钼磷混合价杂多阴离子 [PMo12O40]4ˉ、3个水分子、2个乙醛分子和1个二甲基甲酰胺分子构成。

Calculation of nonlinear optical properties of KNdP4O12

The second-order nonlinear optical (NLO) tensor coefficients of KNdP4O12 (KNP) are theoretically predicted from its crystal structural data, by using the chemical bond theory of complex crystals and the modified bond charge model. Linear and nonlinear optical contributions of each type of bond to the total linearity (chi) and nonlinearity (d(ij)) of KNP are quantitatively determined. The structure-property relationship of KNP is systematically investigated, from the chemical bond viewpoint. Based on the discussion of its structural modifications, we point out that NLO properties of I(NP can be improved effectively using the doping method. Theoretical predictions show KNP to be a promising: self-frequency-doubling laser material.

Determination of the secondary structure of the king cobra neurotoxin CM-11

The king cobra neuotoxin CM-11 is a small protein with 72 amino acid residues. After its complete assignments of H-1-NMR resonance's were obtained using various 2D-NMR technologies, including of DQF-COSY, clean-TOCSY AND NOESY, the secondary structure was analysed by studying the various NOEs extracted from the NOESY spectra and the distribution of chemical shifts. The secondary structure was finally determined by MCD as follows: a triple-strand antiparallel beta sheet with I20-W36, R37-A43 and V53--S59 as its beta strands, a short alpha helix formed by W30-G35 and four turns formed by P7-K10, C14-G17, K50-V53 and D61-N64.

眼镜王蛇蛇毒神经毒素CM-11二级结构单元的判定

眼镜王蛇毒液抽提物ＣＭ－１１为含７２个残基的长链神经毒素，对其进行了ＤＱＦ－ＣＯＳＹ，ＴＯＣＳＹ和ＮＯＥＳＹ等一系列２Ｄ－ＮＭＲ谱测定，通过系统地分析各种ＮＯＥ信息、化学位移的分布等数据推测了蛋白质有规律二级结构，最后利用ＭＣＤ主链引导法确定了它的二级结构。其中有三段反平行β折叠股（Ｉ２０～Ｗ２６、Ｒ３７～Ａ４３和Ｖ５３～Ｓ５９）、一段α螺旋构象（Ｗ３０～Ｇ３５）和四个可能的转角（Ｐ７～Ｋ１０，Ｃ１４～Ｇ１７，Ｋ５０～Ｖ５３，Ｄ６１～Ｎ６４），蛇毒神经毒素ＣＭ－１１其他肽片段处在伸展构象。

Toughening mechanism of polymer blends: Influence of voiding ability of dispersed-phase particles

The parameters which effect the cavitation strain of polymer blends toughened with a shear yield mechanism have been studied by analysis of the stress acted on the equatorial plane of dispersed-phase particles. As a result, the cavitation strain of polymer blends depends on the Young's modulus and the Poisson's ratio of the dispersed-phase particles and the matrix and also on the break stress of dispersed-phase particles. We tried to provide a criterion for selecting the materials used as dispersed-phase particles which can effectively enhance the toughness of polymer blends. (C) 1996 John Wiley & Sons, Inc.

导电炭黑在NBR中的应用

用导电炭黑（ＣＳＦ）作填充剂，研究了它对ＮＢＲ混炼胶加工行为、硫化特性、硫化胶性能及导电性能的影响，并与填充乙炔炭黑（ＡＣＥＴ）的ＮＢＲ胶料性能进行了对比。结果表明，随着ＣＳＦ用量增加，炭黑结合ＮＢＲ含量、门尼粘度、屈服强度和拉伸强度均增加，而扯断伸长率及挤出物出口膨胀比降低，挤出物外观变优；随着ＣＳＦ用量增加，焦烧和正硫化延长，硫化速度及硫化胶强度有所下降，而导电性能变优。硫化胶体积电阻率随硫化时间延长及施加负荷增加而降低，随温度升高和增塑剂邻苯二甲酸二辛酯用量增加而升高。同时表明，ＮＢＲ／ＣＳＦ体系的结合ＮＢＲ含量、门尼粘度、混炼胶应力－应变性能及硫化胶导电性能等均高于ＮＢＲ／ＡＣＥＴ体系。

醋酸纤维素／聚乙烯基吡咯烷酮共混体系的特殊相互作用表征（Ⅱ）

通过测定醋酸纤维素（ＣＤＡ）和聚乙烯基吡咯烷酮（ＰＶＰ）共混物溶液的绝对粘度和特性粘数，发现ＣＤＡ和ＰＶＰ分子链段间有缔合现象．用富里哀变换红外光谱（ＦＴＩＲ）研究了共混物的吸收光谱，发现共混物中ＣＤＡ的羟基吸收峰和ＰＶＰ的羰基吸收峰均向低频方向迁移，证明了ＣＤＡ的羟基和ＰＶＰ的羰基之间有氢键形成．研究结果表明ＣＤＡ和ＰＶＰ的相容性及其特殊相互作用来源于不同分子链段间的氢键相互作用．

YAG：Er晶体中的自饱和跃迁和激光波长红移

用提拉法生长出ＹＡＧ：Ｅｒ晶体，测定和分析了晶体的晶胞参数。讨论了￣２Ｈ＿（１１／２），￣４Ｓ＿（３／２），￣４Ｆ＿（９／２）能级的发光与猝灭，￣４Ｉ＿（１１／２）→￣４Ｉ＿（１３／２）自饱和跃迁的变化规律及激光波长红移的有关因素。

YIELD BEHAVIOR AND VISCOELASTIC INTERPRETATION BY ACTIVATION VOLUMEN OF PHENOLPHTHALEIN POLYETHER KETONE

Phenolphthalein polyether ketone (PEK-C) exhibits a marked tensile yield behaviour. The yield stress depends on strain rate and the activation volume V could be evaluated from the data of the yield stress. From the creep and stress relaxation behaviour,

THE VALENCY AND SPECTRA OF SAMARIUM IONS IN MF(2)-MGF2 (M=CA, SR, BA)

The phosphors MMgF(4)(M = Ca, Sr, Ba) doped with samarium ions are synthesized in different atmospheres using solid phase reaction at high temperature. Samarium has been first stabilized in the divalent state in SrMgF4 and BaMgF4 matrices. Effects of matrices on the valent state of samarium ions are briefly discussed.

FACTORS AFFECTING THE ROLE OF SIO2 IN MGCL2-SUPPORTED ZIEGLER-NATTA COPOLYMERIZATION CATALYSTS

This paper describes the roles of silica (SiO2), the butoxy ligand (-OBu) and ethyl benzoate (EB) on ethylene/1-butene copolymerization with MgCl2/SiO2-supported titanium catalysts. The distribution of SiO2 and of the elements Mg and Ti was observed by means of an energy-dispersed X-ray microanalyzer on a scanning electron microscope (SEM). An inversed Si/Mg ratio results, at invariant Ti/Mg ratio and -OBu content, in higher catalyst efficiency and higher comonomer incorporation, with a correspondingly decreased crystallinity of the copolymers. Thus, the inert carrier SiO2 favors copolymerizability, as seen from the values of the reactivity ratios. The copolymer compositional distribution is also affected by the SiO2 content, as seen from the DSC curves of the copolymers. As to the copolymer morphology, addition of SiO2 makes the copolymer particles larger and more uniform.

高密度聚乙烯与其他聚烯烃共混物高取向薄膜结晶结构的电子显微学研究

本文用透射电子显微镜方法研究了高密度聚乙烯(HDPE)与其它聚烯烃[包括线性低密度聚乙烯(LLDPE)、低密度聚乙烯(LDPE)、等规聚丙烯(iPP)、聚丁烯-1(PB-1)等]共混物高取向薄膜的结晶结构,其中聚烯烃组分含量为10%。在共混物熔体拉伸薄膜中,HDPE以高取向的片晶形式存在,片晶的生长方向垂直于拉伸方向。共混物中LLDPE、LDPE与HDPE形成共晶。与HDPE不相容的iPP、PB-1在共混体系中未观察到明显的相区存在。聚烯烃组分的加入,不仅影响HDPE的片晶尺寸,同时影响结构的对称性,即由纯HDPE的非对称“近单晶”结构变为对称的纤维结构。

稀土甘氨酰替-L-亮氨酸固体配合物及其溶液中构象的研究

稀土生物配体配合物研究对考察稀土生物效应并进而探索其对生态环境和人类健康的影响具有重要意义,稀土二肽配合物研究不多。本文合成并用元素分析和红外光谱研究了稀土元素甘氨酰替-L-亮氨酸固体配合物,采用~(13)C NMR研究了配合物溶液中构象。

聚三甲硅基丙炔膜表面改性的XPS研究——Ⅰ.用N-溴代丁二酰亚胺的表面改性

用N-溴代丁二酰亚胺的丙酮溶液在回流温度下对三甲硅基丙炔的均聚物和共聚物作了表面改性。XPS的研究表明,试样表面层中Br原子含量随溴化时间的增长而增加,C_(IS)谱变宽且产生来自C-O和C-Br结构的新谱线。红外光谱证明溴化反应产生CH_2Br结构。溴化使膜的气透性发生相应的变化,即α_(O_2/N_2)值增高,P_(O_2)值降低。

焙烧对NiO-MoO_3-K_2CO_3/Al_2O_3水煤气变换催化剂的影响

CoO-MoO_3,NiO-MoO_3,CoO-WO_3,NiO-WO_3/Al_2O_3等催化剂在工业上广泛应用于加氢和脱硫过程,对于这类催化剂的研究大多针对此反应.当这类催化剂添加碱金属盐后对水煤气变换反应有明显的促进作用,而对加氢脱硫则显示出负效果.对于水煤气变换反应,这类催化剂最大的特点是能耐高浓度的硫,并具有低温活性.本工作对不同温度处理的NiO-MoO_3-K_2CO_3/Al_2O_3催化剂进行了XRD,XPS,DRS的研究,试图了解焙烧温度对催化剂结构,活性组分存在状态和分布以及催化活性的影响.