间同立构1,2-聚丁二烯的合成和形态结构研究

间同立构1,2-聚丁二烯自1955年问世以来 ,引起人们的广泛关注 ,但绝大多数研究工作集中在聚合物的合成方面[1～3] ,对其形态结构方面的研究却很少报道[4] ,原因是该聚合物分子侧链含有大量双链 ,在较高温度下 (>150℃ )很容易产生热交联 ,这给结构研究造成了很大困难 .间同立构1,2-聚丁二烯的性能取决于间规度 ,低间规度聚合物呈现弹性体特征 ,而高间规度聚合物则是一种半结晶性塑料 ,其结晶为平面锯齿链正交堆砌 ,Pacm空间群[4] .本文采用一种新的催化体系 ,使合成的1,2-聚丁二烯间规度可以调控.同时首次报道了结晶性间规1,2-聚丁二烯稀溶液浇铸薄膜形成具有单晶取向的板条状片层结构,并应用电子显微学和电子衍射技术确定其晶体结构.1.实验部分1.1样品及试剂　乙酰基丙酮铁 [(Fe(acac) 3)纯度为 99.9% ],使用时配成0.2mol/ L的甲苯溶液 ;三异丁基铝 [Al(i-Bu) 3]由 Aldrich公司提供 ;氢化亚磷酸二乙酯 (DEP)及丁二烯由锦州化学公司提供 ;丁二烯通过蒸馏进行纯化 ;己烷使用前在 Na/ K合金...

结晶性间同立构1,2-聚丁二烯的单晶结构

近十几年来,结晶性间同立构1,2-聚丁二烯引起人们的广泛关注,但绝大多数研究工作集中在聚合物的制备、物理性质和应用方面[1～3],对于其结晶行为和晶体结构则未见报道 .原因是间同立构1,2-聚丁二烯分子侧链含有大量的双键,在较高温度下很容易交联 ,特别是高间规度的聚合物 ,由于其熔融温度高 (>200℃ )则更易产生交联,这给结晶行为和结构研究带来很大困难.结晶性间同立构1,2-聚丁二烯的晶体结构为平面锯齿链正交堆砌,Pacm空间群[4].我们曾报道了结晶性间同立构1,2-聚丁二烯的合成和溶液浇铸膜的板条状结构[5],本文采用薄膜熔体结晶的方法第一次成功地获得了间同立构1,2-聚丁二烯的单晶,并通过电子显微学和电子衍射技术确定了其晶体结构.1 实验部分1.1间同立构1,2-聚丁二烯的制备采用乙酰基丙酮铁 [Fe(acac) ]3、三异丁基铝 [Al(i-Bu)3]和氢化亚磷酸二乙酯 (DEP)的新催化体系制备间同立构1,2-聚丁二烯,具体合成路线参见文献 [5].本文所选用聚合物的1,2单元含量为 89.3 % ,间规度为 ...

Patterning and luminescent properties of nanocrystallineY(2)O(3): Eu3+ phosphor films by sol-gel soft lithography

Nanocrystalline Y2O3:Eu3+ phosphor films and their patterning were fabricated by a Pechini sol-gel process combined with a soft lithography. X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), atomic force microscopy (AFM), optical microscopy, UV/vis transmission and photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting films. The results of XRD indicated that the films began to crystallize at 500 degreesC and the crystallinity increased with the elevation of annealing temperatures. Uniform and crack free non-patterned phosphor films were obtained, which mainly consisted of grains with an average size of 70 nm. Using micro-molding in capillaries technique, we obtained homogeneous and defects-free patterned gel and crystalline phosphor films with different stripe widths (5, 10, 20 and 50 mum). Significant shrinkage (50%) was observed in the patterned films during the heat treatment process. The doped Eu3+ showed its characteristic emission in crystalline Y2O3 phosphor films due to an efficient energy transfer from Y2O3 host to them. Both the lifetimes and PL intensity of the Eu3+ increased with increasing the annealing temperature from 500 to 900 degreesC, and the optimum concentrations for Eu3+ were determined to be 5 mol%.

Electrochemiluminescence sensor using tris(2,2 '-bipyridyl)ruthenium(II) immobilized in Eastman-AQ55D-silica composite thin-films

An electrochemiluminescence (ECL) sensor with good long-term stability and fast response time has been developed. The sensor was based on the immobilization of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) into the Eastman-AQ55D-silica composite thin films on a glassy carbon electrode. The ECL and electrochemistry of Ru(bpy)(3)(2+) immobilized in the composite thin films have been investigated, and the modified electrode was used for the ECL detection of oxalate, tripropylamine (TPA) and chlorpromazine (CPZ) in a flow injection analysis system and showed high sensitivity. Because of the strong electrostatic interaction and low hydrophobicity of Eastman-AQ55D, the sensor showed no loss of response over 2 months of dry storage. In use, the electrode showed only a 5% decrease in response over 100 potential cycles. The detection limit was 1 mumol l(-1) for oxalate and 0.1 mumol l(-1) for both TPA and CPZ (S/N = 3), respectively. The linear range extended from 50 mumol l(-1) to 5 mmol l(-1) for oxalate, from 20 mumol l(-1) to 1 mmol l(-1) for TPA, and from 1 mumol l(-1) to 200 mumol l(-1) for CPZ.

Determination of diphenhydramine by capillary electrophoresis with tris(2,2 '-bipyridyl)ruthenium(II) electrochemiluminescence detection

Tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence detection in a capillary electrophoresis separation system was used for the determination of diphenhydramine. In this study, platinum disk electrode (300 mum in diameter) was used as a working electrode and the influence of applied potential and buffer conditions were investigated. Under optimal conditions: 1.2 V applied potential, pH 8.50, 15 kV separation voltage and 10 mmol l(-1) running buffer, the calibration curve of diphenhydramine was linear over the range of 4 x 10(-8) to 1 x 10(-5) Mol l(-1). This technique gave satisfactory precision, and relative standard deviations of migration times and chemiluminescence peak intensities were less than 1 and 6%, respectively. The technique was applied to animal studies for determination of diphenhydramine extracted from rabbit plasma and urine samples, and the extraction efficiency were between 92 and 98.5%.

3{1-[2-(-3-羟基-1-甲基-2-亚丁烯氨基)-苯亚氨基]-乙基}4-甲硫基-2,4-戊二烯-2-醇的不对称Schiff碱镍(Ⅱ)配合物的合成、结构和性质

由 5-(2-乙酰基-1-甲硫基-3-羰基-亚丁基)-丙二酸亚异丙酯 (1)与邻苯二胺及乙酸镍()经一步反应合成了3{1-[2-( -3-羟基-1-甲基-2-亚丁烯氨基)-苯亚氨基 ]-乙基} 4-甲硫基-2,4-戊二烯-2-醇(3)的不对称四齿 Schiff碱镍()配合物(2),X射线衍射结果表明,配合物 2属单斜晶系,P21/C空间群.a=1.1476(2)nm,b=1.1782(2)nm,c=1.4810(3)nm;β=111.73(2)°,V=1.8602(7)nm3,Z=4,Rf=0.0535.电化学(循环伏安)测定结果表明,该配合物在测定条件下(阳极峰电位为1.1)发生了不可逆的氧化-还原反应.

Synthesis of substituted indenyl lanthanide chloride and molecular structure of [(C5H9C9H6)(2)Yb(mu-Cl)(2)Li(Et2O)(2)]

Reaction of anhydrous ytterbium trichlorides with 2 equiv. of cyclopentylindenyl lithium in THF solution, followed by removal of the solvent MO. crystallization of the product from diethyl ether, affords a crystal complex of the composition (C5H9C9H6)(2)Yb(mu-Cl)(2)Li(Et2O)(2). Crystallographic analysis shows that the ytterbium coordinated by two cyclopentylindenyl rings and lithium surrounded by two ether molecules are bridged by the two chlorine atoms and Yb, U and two chlorine atoms form a plane.

抗病、优质春小麦新品种--墨引1号和墨引2号

墨引1号(原代号99-22)、墨引2号(原代号99-36)是中国科学院西北高原生物研究所和青海省农业技术推广总站共同承担国家"948"项目即《国际玉米小麦改良中心(CIMMYT)春小麦新品种(系)引进和栽培试验研究》项目,通过引进、定向选育而成的两个春小麦新品种.这两个品种于2000～2003年参加青海省水地春小麦区域试验和生产试验,2004年2月19日通过青海省农作物品种审定委员会审定,分别定名为墨引1号、墨引2号.

Los diferentes tipos de láser y sus aplicaciones en podología

Los diferentes tipos de láseres, sobre todo el láser de diodo, irrumpen en la terapéutica podológica para proporcionar una alternativa más de tratamiento en muchas patologías que son el día a día de las consultas. El buen manejo y el conocimiento de sus características son requisitos imprescindibles para no tener efectos secundarios indeseados y poder llevar a cabo tratamientos poco dolorosos, minimizando el tiempo total, y muchas veces proporcionando una solución a diversas patologías.

Second Metatarsophalangeal joint Synovitis: Update

In podiatric clinics is very common to find inflamatory process in metatarsophalangeal joint capsule , plantar plate and collateral ligaments damage, but it is not clearly recognized. Many authors hipotetized with joint instability of multiple aetiology and his concomitant evolution in different stages with own joint disease. This pathology has more incidence in second metatarsophalangeal joint than third and others and it is a common etiology of metatarsal pain. Bad biomechanics alters forefoot function and can produce overload in capsular joint, decreasing mobility and getting worse the pathology.

A onda de calor de Agosto de 2003 e os seus efeitos sobre a mortalidade da população portuguesa

RESUMO - Portugal continental, como outros países europeus, foi afectado por uma onda de calor de grande intensidade no Verão de 2003, com efeitos na mortalidade da população. O excesso de óbitos associados à onda de calor foi estimado pela comparação do número de óbitos observados entre 30 de Julho e 15 de Agosto de 2003 e o número de óbitos esperados se a população tivesse estado exposta às taxas de mortalidade médias do biénio 2000-2001 no respectivo período homólogo. Os óbitos esperados foram calculados com ajustamento para a idade. O número de óbitos observados (O) foi superior ao número esperado (E) em todos os dias do período estudado e o seu excesso global foi estimado em 1953 óbitos (excesso relativo de 43%), dos quais 1317 (61%) ocorreram no sexo feminino e 1742 no grupo de 75 e + anos (89%). A nível distrital, Portalegre teve o maior aumento relativo do número de óbitos (+89%) e Aveiro o menor (+18%). Numa área geográfica contínua do interior do território (Guarda, Castelo Branco, Portalegre e Évora) houve aumentos relativos superiores a 80%. Em termos absolutos, o maior excesso de óbitos ocorreu no distrito de Lisboa (mais cerca de 396) e no do Porto (mais cerca de 183). As causas de morte «golpe de calor» e «desidratação e outros distúrbios metabólicos» tiveram os aumentos relativos mais elevados (razões O/E de, respectivamente, 70 e 8,65). Os maiores aumentos absolutos do número de óbitos ocorreram no grupo das «doenças do aparelho circulatório» (mais 758), nas «doenças do aparelho respiratório» (mais 255) e no conjunto de «todas as neoplasias malignas» (mais 131). No período da onda de calor e no período de comparação, a percentagem dos óbitos que ocorreu nos hospitais (52% e 56%), no domicílio (32 e 33%) e em «outros locais» foi semelhante. A discussão sobre os factores que condicionaram a obtenção dos valores apresentados, relativos ao excesso de óbitos por sexo, grupo etário, distrito, causa e local da morte, permite concluir que os mesmos se afiguram adequados para medir a ordem de grandeza e caracterizar o efeito da onda de calor na mortalidade. O erro aleatório, medido pelos intervalos de confiança, e alguns possíveis erros sistemáticos associados ao período de comparação escolhido não deverão afectar de modo relevante as estimativas.