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91.
The photoluminescence of Co-Al-layered double hydroxide   总被引:1,自引:0,他引:1  
We report a new optical behaviour of pure Co-Al-layered double hydroxide (LDH).It was found that the Co-Al-LDH sample could emit fluorescence without any fluorescent substances intercalated.Its excitation spectrum shows a maximum peak near the wavelength 370nm,the maximum emission peak appears at 430 nm and the photoluminescence colour of the Co-Al-LDH sample is blue.This new optical property will be expected to extend the potential applications of LDHs in optical materials field.  相似文献   
92.
表皮生长因子受体和抑制剂之间分子对接的研究   总被引:3,自引:0,他引:3  
研究了表皮生长因子受体(EGFR)和4-苯胺喹唑啉类抑制剂之间的相互作用模式,表皮生长因子受体的三维结构通过同源蛋白模建的方法得到,而抑制剂和靶酶结合复合物结构则通过分子力学和分子动力学结合的方法计算得到。从模拟结果得到的抑制剂和靶酶之间的相互作用模式表明范德华相互作用、疏水相互作用以及氢键相互作用对抑制剂的活性都有重要的影响,抑制剂的苯胺部分位于活性口袋的底部,能够与受体残基的非极性侧链产生很强的范德华和疏水相互作用,抑制剂双环上的取代基团也能和活性口袋外部的部分残基形成一定的范德华和疏水性相互作用,而抑制剂喹唑啉环上的氮原子能和周围的残基形成较强的氢键相互作用,对抑制剂的活性有较大的影响,计算得到抑制剂和靶酶之间的非键相互作用能以及抑制剂和靶酶之间的相互作用信息能够很好地解释抑制剂活性和结构的关系,为全新抑制剂的设计提供了重要的结构信息。  相似文献   
93.
The complete gene coding for human neutrophilactivating protein-1/interleukin-8 was synthesized using a semi-chemical semi-enzymatic method. The synthetic gene was then overexpressed in Escherichia coli under the temperature-regulated control of the P_RP_L tandem promoters. As determined by SDS-PAGE and densitometry, the overexpressed protein comprised up to 18.5% and 10.9% of the total soluble protein in E. coli cells grown in shake flasks and in batch fermentation, respectively. The recombinant NAP-1/IL-8 was then purified to>95% homogeneity by gel filtration and cation exchange chromatography. The purified protein appeared as a single band on the SDS-PAGE gel and possessed potent chemotactic activity in the concentration of <10 ng/ml, as assayed by the agarose plate method. An early skin reactivity was also observed when the pure NAP-1/IL-8 was injected subcutaneously into the rabbits. The N-terminal 36 amino acid sequence of the recombinant NAP1/IL-8 was determined using the Edman method and was sho  相似文献   
94.
The relationship among intrinsic surface reaction constant (K) in 1-pK model, point of zero net charge (PZNC) and structural charge density (σst) for amphoteric solid with structural charges was established in order to investigate the effect of σst on pK. The theoretical analysis based on 1-pK model indicates that the independent PZNC of electrolyte concentration (c) exists for amphoteric solid with structural charges. A common intersection point (CIP) should appear on the acid-base titration curves at different c, and the pH at the CIP is pHPZNC. The pK can be expressed as pK=-pHPZNC log[(1 2αPZNC)/(1-2αPZNC)], where αPZNC≡σst/eNANs, in which e is the elementary charge, NA the Avogadro‘s constant and Ns the total density of surface sites. For solids without structural charges, pK=-pHPZNC. The pK values of hydrotalcite-like compounds (HTlc) with general formula of [Mg1-xFex(OH)2](Cl,OH)x were evaluated. With increasing x, the pK increases, which can be explained based on the affinity of metal cations for H^- or OH^- and the electrostatic interaction between charging surface and H^- or OH^-.  相似文献   
95.
The enthalpy change of formation of the reaction of hydrous dysprosium chloride with ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline (o-phen?H2O) in absolute ethanol at 298.15 K has been determined as (-16.12 ± 0.05) kJ?mol-1 by a microcalormeter. Thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), rate constant and kinetics parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of the reaction have also been calculated. The enthalpy change of the solid-phase reaction at 298.15 K has been obtained as (53.59 ± 0.29) kJ?molt-1 by a thermochemistry cycle. The values of the enthalpy change of formation both in liquid-phase and solid-phase reaction indicated that the complex could only be synthesized in liquid-phase reaction.  相似文献   
96.
A new 1,3,4 thiadiazole-derivative ligand 2,5-(s-acetic acid) dimercapto-1,3,4 thiadiazole (H2ADTZ) and its one-dimensional manganese polymer Mn(ADTZ)·4H2O had been synthesized and structurally characterized by X-ray single crystal diffraction in this paper. The Mn(Ⅱ) ion is coordinated with a distorted octahedron by two oxygen atoms from neighboring two deprotonated ligands ADTZ2- and other four oxygen atoms from four coordinated water molecules. The structural feature of the title compound is the formation of one-dimensional manganese chains polymer through the bridging of dioxygen O-O units. In the solid state structure of the complex, one-dimensional manganese chains are joined together by the weak intermolecular hydrogen bonds and vander Waals interactions forming a two-dimensional supramolecular compound. Furthermore, the UV spectra and electro-chemical properties of the title compound were also investigated. CCDC: 260532.  相似文献   
97.
Polymeric pendant Ru(bpy)_3~(2+) complexes were prepared from homopolymer and copolymers of 4-methyl-4'-vinyl-2,2'-bipyridine (Vbpy). Vbpy was prepared from 4-methylpyridine. The comonomers were styrene (St), acrylic acid (AA), N-vinylpyrrolidone (Pyr), 4-vinylpyridine (Vpy), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), acrylonitrile (AN) and N-ethyl-4-vinylpyridium bromide (EQ-Vpy). The fraction of the pendant Ru(bpy)_3~(2+) repeating unit in the polymeric complex was 0.022 to 0.052. Absorption maximum, molar extinction coefficient, emission maximum and relative emission intensity of the polymeric complexes were studied.  相似文献   
98.
胡艾希  陈平  袁帅  周勇 《合成化学》2002,10(4):333-334
室温下,6-甲氧基-2-丙酰基萘和1,3-二溴-5,5-二甲基海因的溴化反应在醇溶剂中,反应速度快、转化率高,生成5-溴-6-甲氧基-2-丙酰基萘的收率高(98.59%)。  相似文献   
99.
Cobalt(Ⅱ) can form complexes with Hdbm in different environments. Hdbm reacted with cobalt nitrate to give complex 1 [Co(dbm)2·2H2O]. When complex 1 reacted with pyridine, α-stilbazole or 4,4′-bipyridine respectively, complex 2 [Co(DBM)2Py2] (Py=pyridine), 3 [Co(DBM)2Sbz2] (Sbz=α-stilbazole) or 4 [Co(DBM)2BPy]n was obtained in turn through metathetical reaction. The coordination modes are octahedral polyhedrons. In the crystal structures, the two dbms take the plane position and two other donor molecules take the axial position. CCDC: 196070 for complex 2; 186859 for complex 3.  相似文献   
100.
将Fe2O3纳米粉体经一定浓度的H2SO4浸泡活化后制成纳米固体超强酸SO42-/Fe2O3,将其用于催化合成乙酸乙酯以考察其活性。利用均匀设计分析了超强酸制备过程及酯化反应过程中各因素的影响,研究结果表明较好的制备条件是:H2SO4浓度:2.5mol·L-1;浸泡时间:1h;活化温度:167℃;活化时间:1h,此时获得的固体超强酸SO42-/Fe2O3的粒径小于50nm。当催化剂用量为冰乙酸质量的5%,n(乙醇)∶n(冰乙酸)为3∶1,反应3.5h后乙酸的转化率高于80%。该催化剂经H2SO4溶液浸泡、活化再生后可重新使用,推断出其酸强度H0<-14.5。  相似文献   
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