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排序方式: 共有832条查询结果,搜索用时 15 毫秒
11.
多相催化反应原位红外系统及其应用 总被引:1,自引:0,他引:1
设计和建立了一套能耐高温的用于多相催化反应研究的原位红外系统,反应温度从室温到1150K,系统真空为1.0*10^5-1.0-10^-4Pa,红外光谱检测范围为4800-200cm^-1。此系统扩展了原仪器的功能,提高了仪器利用率和效率。 相似文献
12.
In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contactangle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorptionamount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly withincreasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both thehydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates. 相似文献
13.
2A12-T6铝合金表面双-(γ-三乙氧基硅丙基)四硫化物薄膜的特性 总被引:2,自引:0,他引:2
采用傅立叶变换红外光谱分析了2A12-T6铝合金表面自组装双-(!-三乙氧基硅丙基)四硫化物硅烷偶联剂(SCA)薄膜结构特征,并采用电化学极化曲线评价了薄膜的耐蚀性能.结果表明,铝材表面自然晾干,SCA薄膜分子之间主要通过氢键连接,腐蚀电流密度减小1个数量级以上.120℃的加热处理促进铝板表面通过SiOSi链接而形成SCA网状薄膜结构,并通过在界面上形成SiOAl界面相结构而与铝板表面牢固连接,腐蚀电流密度降低2个数量级以上.SCA乙醇溶液浸泡处理10min比浸泡2s~1min的铝板表面SCA薄膜内氢键缔合羟基要多. 相似文献
14.
Huiguang Kou 《European Polymer Journal》2004,40(7):1337-1342
A novel hyperbranched polyisophthalate containing pendant carbazolyl and azobenzene groups at the terminals was synthesized, and its photorefractivity has also been evaluated by the effective electro-optic (EO) coefficient, two-beam couple (TBC) coefficient, diffraction efficiency and photorefractive (PR) response time. This PR polymer has a low glass transition temperature of 21 °C without any extra plasticizer added, which provides a necessary free volume for EO chromophore reorientation during the recording process at room temperature. The obtained PR film exhibited an effective EO coefficient of 30 pm V−1, a TBC coefficient of 59 cm−1, a diffraction efficiency of 17%, and a modulation index of 1.67 × 10−3 at the wavelength of 632.8 nm with an applied electric field of 80 V μm−1 at room temperature. The TBC coefficient was found to be beam-intensity dependent, compared with what is found in inorganic crystals. Moreover, a fast PR response time of 10 ms was deduced at an erasing beam intensity of 1.0 W cm−2. 相似文献
15.
Ozeki H Nomoto A Ogawa K Kobuke Y Murakami M Hosoda K Ohtani M Nakashima S Miyasaka H Okada T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(24):6393-6401
We synthesized special-pair/electron-acceptor systems consisting of a complementary slipped cofacial dimer of imidazolyl-substituted zinc porphyrin, bearing pyromellitdiimide as the electron acceptor. In the case of the dimer, the first and second oxidation potentials were split into a total of four peaks in the differential pulse voltammetry measurement. Furthermore, the shift values of the first oxidation potentials obtained by changing the solvent polarity for the dimer were almost half of those observed for the monomer. These results indicate that the radical cation is delocalized over the whole pi system of the dimer. Time-resolved transient absorption measurements revealed that, relative to the corresponding monomer, the dimer accelerated the charge separation rate, but decelerated the charge recombination rate. The smaller reorganization energy of the slipped cofacial dimer relative to that of the monomeric system demonstrates the significance of the special-pair arrangement for efficient charge separation in photosynthesis. 相似文献
16.
改性Y分子筛的酸碱性能及吸附性能的研究 总被引:2,自引:1,他引:2
吡啶、吡咯、苯、甲苯、乙苯作为探针分子,在Li+, Na+, K+, Cs+改性的Y型分子筛上进行吸附,用TPD及IR方法系统地研究了不同碱金属离子改性的Y型分子筛的酸碱性能和吸附性能的变化. 结果表明,按Li、Na、K、Cs的顺序, 随着碱金属离子半径的增大, 其L酸酸强度依次减弱,L碱的强度逐渐增强.由于改性Y型分子筛所含碱金属离子的不同,其对芳烃的吸附的强弱及吸附量的大小亦不同.随着骨架外的阳离子的半径逐渐增大,碱的强度逐渐增强,与芳烃的作用愈强烈,导致TPD脱附峰温增高及芳烃和侧链上的C-H伸缩振动谱带向低波数位移愈多.由于位阻的原因,对含同一种碱金属离子的分子筛来说,随着芳烃侧链C数的增加,芳烃的吸附量逐渐减小. 相似文献
17.
铜(II)-5-取代邻菲啰啉-二氧四胺大环三元体系的稳定性研究 总被引:1,自引:0,他引:1
The stability of copper (Ⅱ)-13-(2'-Hydroxy-3',5'-substituted benzyl)-1,4,8,11-tetraazacyclotetradecane-12, 14-dione(RTADO-14) binary complex compounds and of copper (Ⅱ)-5-substituted-1,10-phenanthrolines(R'TADO)-RTADO-14 ternary complex compounds was studied by means of pH titration method at 25.0±0.1 ℃ and I=0.1mol?dm-3KNO3. The formation constants of binary and ternary complexes were obtained. The structures of the binary and ternary complxes and the effects fo substituents on macrocyclic ligands and on R'Phen were also discussed. 相似文献
18.
CONVERSION OF METHANE AND CARBON DIOXIDE TO AROMATICS OVER CHROMIUM-BASED CATALYSTS:SELECTIVITY AND YIELD OF MAIN PRODUCTS 下载免费PDF全文
在840℃,0.5MPa,CH4/CO2摩尔比为1.4,接触时间(W/F)为0.79h·g·L-l的条件下,甲烷和二氧化碳在7.5wt%Cr/5.0wt%Na/SiO2催化剂上共活化得到了4.8%的C2选择性,48.7%的芳烃选择性及1.9%的芳烃收率。在钠修饰的铬基催化剂上,成功地一步实现了CH4和CO2转化为乙烯及中间物乙烯聚合为芳烃的过程 相似文献
19.
程序涂渍柱“柱效能程序效应”的研究 总被引:1,自引:0,他引:1
本文从理论上给出程序柱“柱效能程序效应”的概念并导出了函数关系式,通过计算机可计算柱效能程序效应与柱内各变量之间的关系,实践证明实验数据的变化趋势与理论数据相符。 相似文献
20.
Ni ZH Kou HZ Zheng L Zhao YH Zhang LF Wang RJ Cui AL Sato O 《Inorganic chemistry》2005,44(13):4728-4736
Two new cyano-bridged heterobinuclear complexes, [Mn(II)(phen)2Cl][Fe(III)(bpb)(CN)2] x 0.5CH3CH2OH x 1.5H2O (1) and [Mn(II)(phen)2Cl][Cr(III)(bpb)(CN)2] x 2H2O (2) [phen = 1,10-phenanthroline; bpb(2-) = 1,2-bis(pyridine-2-carboxamido)benzenate], and four novel azido-bridged Mn(II) dimeric complexes, [Mn2(phen)4(mu(1,1)-N3)2][M(III)(bpb)(CN)2]2 x H2O [M = Fe (3), Cr (4), Co (5)] and [Mn2(phen)4(mu(1,3)-N3)(N3)2]BPh4 x 0.5H2O (6), have been synthesized and characterized by single-crystal X-ray diffraction analysis and magnetic studies. Complexes 1 and 2 comprise [Mn(phen)2Cl]+ and [M(bpb)(CN)2]- units connected by one cyano ligand of [M(bpb)(CN)2]-. Complexes 3-5 are doubly end-on (EO) azido-bridged Mn(II) binuclear complexes with two [M(bpb)(CN)2]- molecules acting as charge-compensating anions. However, the Mn(II) ions in complex 6 are linked by a single end-to-end (EE) azido bridging ligand with one large free BPh4(-) group as the charge-balancing anion. The magnetic coupling between Mn(II) and Fe(III) or Cr(III) in complexes 1 and 2 was found to be antiferromagnetic with J(MnFe) = -2.68(3) cm(-1) and J(MnCr) = -4.55(1) cm(-1) on the basis of the Hamiltonian H = -JS(Mn)S(M) (M = Fe or Cr). The magnetic interactions between two Mn(II) ions in 3-5 are ferromagnetic in nature with the magnetic coupling constants of 1.15(3), 1.05(2), and 1.27(2) cm(-1) (H = -JS(Mn1)S(Mn2)), respectively. The single EE azido-bridged dimeric complex 6 manifests antiferromagnetic interaction with J = -2.29(4) cm(-1) (H = -JS(Mn1)S(Mn2)). Magneto-structural correlationship on the EO azido-bridged Mn(II) dimers has been investigated. 相似文献