Studies on plant calmodulin and its interaction with antagonist W-7 by Ln(3+) luminescence probes

Plant calmodulin (CaM) has been extracted from cauliflower, and the purified CaM has been identified with the activation of NAD kinase (NADK) and the inhibition effect of CaM antagonist W-7. CaM's intrinsic fluorescence and Tb3+ fluorescence showed that there was one tyrosine residue and four metal-binding sites in cauliflower CaM. Based on Forster-type nonradiative energy theory, the distances of Tyr --> site III, IV have been determined, and these are 1.23 nm (Tyr --> site III ) and 1.18 nm(Tyr --> site IV). The Eu3+ and Tb3+ fluorescence probes showed that the combination of CaM with W-7 resulted in significant change on CaM's conformation, but did not affect coordination environment of metal-binding sites.

(+/-)-7,7,9,9-Tetramethyl-2,3 : 4,5-dinaphthol,6,8-trioxa-7,9-disilacyclonona-2,4-diene

The title compound, C24H24O3Si2, is a twofold symmetric silicocrown ether with the two dimethylsilyl groups attached to the O atoms of 1,1'-bi-2-naphthol, and bridged by another O atom.

Structure and order of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene as revealed by diffraction and molecular simulation studies

The aggregate structure of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene (HPT) was studied both for the crystalline state and the liquid crystalline state by using electron crystallography and a molecular simulation approach. In the crystalline state, HPT was found to adopt an orthorhombic P-2212 space group with cell parameters a = 36.73 Angstrom, b = 27.99 Angstrom and c = 4.91 Angstrom. Molecular packing calculations were conducted to elucidate the molecular conformation and mutual orientational characteristics in the different states. Phase transitions and relationships are discussed from a structural point of view.

STUDIES ON THE SYNTHETIC, STRUCTURAL, ELECTRICAL, AND MAGNETIC-PROPERTIES OF THE NEW LAYERED OXIDES LN(2)MCO(2)O(7) (LN=SM, GD, M=SR, BA)

Three new oxides Ln(2)MCo(2)O(7) (Ln = Sm, Gd; M = Sr, Ba) have been synthesized in solid state reaction method. The powder X-ray diffraction spectra show that they are all isostructural with Sr3Ti2O7. The electrical resistivities in the temperature range 300-1100 K show that they are all semiconductors, and a transition to metals is observed at 1053, 1053, and 573 K for Sm2SrCo2O7, Gd2SrCo2O7, and Sm2BaCo2O7, respectively. The magnetic suspectivities of Gd2SrCo2O7 in the temperature range 300-673 K fit the Curie-Weiss law well. A plateau is observed in the curves of Sm(2)MCo(2)O(7) (M = Sr, Ba) which is attributed to the configuration state change of Co(III) from low spin to high spin. (C) 1995 Academic Press, Inc.

2－取代肉桂酰基－7－甲胺基酮的合成

２－乙酰－７－甲胺基酮与取代苯甲醛在氢氧化钠溶液存在下进行缩合反应，得到６种２－取代肉桂酰基－７－甲胺基酮．它们的结构经ＩＲ、１ＨＮＭＲ和元素分析证实，且为反应．

取代基效应(SCS)与乙烯—α—烯烃共聚物的序列结构——7.氢化丁苯共聚物(HBS)

测定了两个氢化丁苯共聚物样品的~1H、~(13)C NMR谱。通过处理文献中的~(13)C NMR谱数据得到了-C_2H_5和-C_6H_5的SCS参数。利用乙烯-α-烯烃共聚物的SCS方法结合DEPTNMR实验技术重新归属了该共聚物的~(13)C NMR谱。明确指出,氢化丁苯共聚物分子链中主链任何一个乙烯单元的两个CH_2在序列分布上分属于二元组和三元组。CH则用三元组来表征。最后,对HBS共聚物的序列分布进行了计算。

7-碘-8-羟基喹啉-5-磺酸-溴化十六烷基三甲铵荧光光度法测定痕量镥

本文研究了镥-Ferron-表面活性剂三元荧光体系的荧光特性,各种表面活性剂中以溴化十六烷基三甲铵的增敏效果最佳,与相应的二元体系相比较,灵敏度提高近10倍。镥的测定下限可达8.8ng/ml。本法与P_(507)萃取色谱分离法相结合可用于天然混合稀土氧化物中痕量镥的测定,结果较满意。

VB族元素掺杂对YBa_2Cu_3O_(7-y)电子结构的影响

合成了YBa_2Cu_(3-x)M_xO_(7-y)(M=V,Nb,Ta;x-0.0～0.7)高温超导体。X-射线粉末衍射分析表明,x≤0.6时,体系仍然是正交结构,没有发生正交到四方的相变。体系的晶胞参数随x的不同而异。体系的电阻率和Hall系数随x的增加而逐渐增加,它们的载流子浓度和载流子迁移率却随x的增加而下降。这说明VB族元素的置換影响了YBa_2Cu_3O_(7-y)的电子结构。用晶体场理论对体系的电子结构作了解释。

SYNTHESIS AND CRYSTAL-STRUCTURE OF NEODYMIUM COMPLEX OF 1-METHYL-1, 4, 7, 10-TETRAAZACYCLODODECANE

The complex [Nd(L)(CH3CN)(CF3SO3)3] has been synthesized. Where L = 1-methyl-1, 4, 7, 10-tetraazacycldodecane. The crystal structure of the complex has been determined by a four-circle X-ray diffractometer to a final deviation factor B value of 0.0370 and R(w) value of 0.0385 respectively. The crystal is triclinic system, space group P1BAR with a = 0.8738(2), b = 1.2870(3), c = 1.2900(3) nm, alpha = 85.63(2), beta = 87.25(2), gamma = 78.30(2)-degrees, V = 1.41571 (60) nm3, Z = 2, D(c) = 1.92 g/cm3. The neodymium ion is eight-coordinated to forming a distorted square antiprism.

Vb族元素掺杂对YBa_2 Cu_3 O_(7-y)载流子浓度的影响

众所周知,在YBa_2Cu_3O_(7-y)中Cu_1-O链起着稳定晶体结构和向体系提供载流子的作用,而Cu_(2-)O面则影响超导电子的运动。因此,利用Vb族元素可以提供更多的自由电子的特点来进行掺杂对研究YBa_2Cu_3O_(7-y)超导体中超导电子的运动和Cu—O链、Cu—O面的作用是很有意义的。

高温超导体EuBa_2(Cu_(1-x)Fe_x)_3O_(7-y)的穆斯堡尔谱学新研究

利用~(57)Fe和~(151)Eu穆斯堡尔效应对EuBa_2(Cu_(1-x)Fe_x)_3O_(7-y)高温超导体作了研究。在液氮温区,分别测量了样品中有和无电流通过时的~(57)Fe穆斯堡尔谱,结果表明取代了Cu(2)位置的Fe的同质异能位移和四极分裂与通过超导体的电流无关,而取代Cu(1)位置的Fe的穆斯堡尔谱参数则与电流有关。不同Fe含量样品的穆斯堡尔谱分析表明,超导电性和穆斯堡尔谱参数都与Fe的含量有关。

LnBa_2C_3O_(7-δ)(Ln=Pr、Y)体系的XPS研究

该文研究了YBa_2Cu_3O_(7-δ)和PrBa_2Cu_3O_(7-δ)两体系的XPS谱图,结果表明从XPS图中难以判断三价铜的存在,与YBa_2Cu_3O_(7-δ)体系相比,PrBa_2Cu_3O_(7-δ)体系中Ba的结合能低,O_(18)的两个状态变得模糊不清。讨论了空穴浓度对高T_c超导电性的影响。

1-甲基-1,4,7,10-四氮杂环十二烷镧配合物的合成及晶体结构

合成了1-甲基-1,4,7,10-四氮杂环十二烷(L)配体。在乙腈中培养了La(L)(CH_3CN)-(H_2O)(CF_3SO_3)_3配合物单晶,测定了其红外光谱和质子核磁共振谱。用X射线衍射方法测定了配合物的晶体结构,该晶体属于单斜晶系,P2_1/n空间群,a=0.9700(2)nm,b=1.5966(2)nm,c=1.9085(1)nm,β=104.71(3)°,V=2.8588(50)nm~3。配合物中镧为9配位,其配位多面体为扭曲的单帽四方反棱柱体。

WATER-SOLUBLE AND AMPHIPHILIC POLYMERS .7. SYNTHESIS AND CHARACTERIZATION OF A NOVEL COMB-TYPE AMPHIPHILIC POLYMER PAMC16S

A novel comb-like amphiphilic polymer, poly (2-acrylamidohexadecylsulfonic acid) (PAMC16S), was synthesized by free radical polymerization of the corresponding amphiphilic monomer in 1,4-dioxane-water mixed solvents. Depending on the ratio of water/dioxane in the solvent, the reaction proceeded by either precipitation polymerization or micellar polymerization. The molecular weight of the polymer obtained under similar conditions decreased and subsequently increased with the increase of water content in the mixed solvent. The polyion nature of PAMC16S was confirmed by viscosity data of ethanolic solutions. In addition, the polymer was characterized by solubility, IR, TG and wide angle X-ray diffraction methods.

三价稀土离子半径对LnBa_2Cu_3O_(7-δ)化合物的结构及超导电性的影响

合成了LnBa_2Cu_3O_(7-δ)(Ln=La,Nd,Sm,Eu,Gd,Dy,Er,Yb)系列化合物,通过XRD,XPS第手段研究了Ln(Ⅲ)离子半径对LnBa_2Cu_3O_(7-δ)化合物的结构及超导性的影响。Ln(Ⅲ)离子的固有磁矩(或4f电子)并不影响LnBa_2Cu_3O_(7-δ)化合物的超导电性,但是,Ln(Ⅲ)离子的大小却显著影响LnBa_2Cu_3O_(7-δ)化合物的微观结构(尤其是对Cu_2周围环境的影响)。XPS结果表明:尽管Cu_(2P3)/2的峰未劈裂,但Cu的结合能随Ln原子序数增加而明显增加,我们认为Cu_1和Cu_2都具有变价,介于2—3之间。