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以1,4-二(3-氨基丙基)哌嗪(BAPP)与对羟基苯甲醛(PHBA)为原料,合成了含哌嗪环的双对羟基苯甲醛Schiff碱——N,N'-二(4-羟基苄基)-1,4-二(3-亚氨基丙基)哌嗪;产物结构经元素分析、红外光谱、核磁共振氢谱和紫外光谱进行确认。采用紫外吸收光谱法和黏度法研究了标题化合物与小牛胸腺DNA(CT-DNA)的相互作用,发现紫外吸收光谱出现了减色效应和红移现象,DNA的相对黏度随着化合物浓度的增大而增加,这些现象说明该双Schiff碱以插入方式与CT-DNA结合。 相似文献
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以5,5'-亚甲基双水杨醛和2-(2-氨基苯胺基)-3-氰基-5-甲基噻吩为原料合成了一种新颖的含噻吩双水杨醛Schiff碱化合物5,5'-亚甲基双水杨醛缩-2-(2-氨基苯胺基)-3-氰基-5-甲基噻吩席夫碱,而5,5'-亚甲基双水杨醛由水杨醛和三聚甲醛缩合制得。元素分析和质谱结果证实,该Schiff碱的分子式为C39H30N6O2S2,红外光谱和1HNMR确证了其结构。用牛津杯琼脂扩散法测定了标题化合物的抑菌性能,结果表明,该Schiff碱对4种菌均有一定的抑制效果,质量浓度为1.5 g/L时,对大肠杆菌的抑菌环直径达15.0 mm,其抑菌活性为大肠杆菌>枯草芽孢杆菌>金黄色葡萄球菌>表皮葡萄球菌。 相似文献
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合成了未见报道乙二醛双缩4-氨基安替比林、丁二酮双缩4-氨基安替比林和其它Schiff碱.对这些化合物进行了元素分析、红外、紫外和核磁谱的表征.对化合物进行了抗超氧阴离子活性的研究.试验表明,这些化合物都有抗超氧阴离子活性. 相似文献
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常温下,以5-氟尿嘧啶为起始原料,以1-乙基-3-(3-二甲氨基丙基)碳二亚胺(EDCI)和1-羟基苯并三氮唑(HOBt)为缩合剂,通过液相偶联法,合成了2-(5-氟尿嘧啶-1-基乙酰基)氨基乙酸甲酯,收率72%;控制pH=10~11,温度20~30℃水解得到相应的2-(5-氟尿嘧啶-1-基乙酰基)氨基乙酸,收率75%。两个化合物的结构通过1HNMR、13CNMR、MS、IR确证;通过紫外吸收光谱初步揭示了化合物的抗肿瘤机制;委托国家新药筛选中心进行了体外抗白血病细胞株HL-60和肝癌细胞株BEL-7402活性测试,结果表明,该化合物具有一定的体外抑制肿瘤作用。 相似文献
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以4-硝基邻苯二甲腈、亚氨基二乙酸、二丙胺等化合物为原料,合成了一种不对称氨基锌酞菁,即2(3)-(N,N-二乙酸氨基)-9(10),16(17),23(24)-(N,N-二丙基氨基)锌酞菁(TPC)。通过红外光谱、紫外-可见光谱、元素分析和核磁共振氢谱表征其结构,比较了产物在N,N-二甲基甲酰胺(DMF)溶液及敏化的纳米TiO2薄膜中的紫外-可见光谱;结合紫外-可见光谱、循环伏安曲线和差分脉冲伏安曲线,确定了基态氧化电位和激发态氧化电位能级位置。结果表明,所合成的化合物具有良好的溶解性,一定浓度范围内在DMF中不发生集聚现象,紫外.可见光谱发生明显红移,能级与纳米TiO2薄膜匹配,可用于制备染料敏化太阳能电池。 相似文献
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Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials 总被引:4,自引:0,他引:4
Previous research indicated that the expansion property of MgO-type expansive agent (MEA) depended strongly on the calcining conditions, i.e. kiln temperature and residence time. However, the intrinsic effect of calcination condition on the expansion property of MEA has not been clearly demonstrated. In the present work, the effects of calcination condition on the microstructure, hydration activity, and expansion property of MEA have been investigated, and their correlations are also studied. Results indicate that the microstructure of MEA is the intrinsic factor that controlling its expansion property, which is influenced by the calcination condition. MEA produced under higher temperature and longer residence time has less interior pores, larger crystal size of MgO, and smaller specific surface area, thus resulting in lower hydration activity and slower expansion at early age, but larger “ultimate” expansion at late age. While, a new expansion model of MEA is proposed to explain these results. 相似文献
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Siham Kamali Micheline Moranville Stéphanie Leclercq 《Cement and Concrete Research》2008,38(4):575-585
Results already published on the leaching of cement pastes have shown that the kinetics depends sensitively on the material and environment. However and because of the variability of the tested materials and leaching protocols, it is difficult to compare these data and quantify the effect of each parameter. In this paper, a large experimental database on the leaching kinetics of cement pastes is built. Four parameters are investigated: type of cement (portland cement, silica fume cement, slag cement, ternary cement with slag and fly ash); water-to-cement ratio (0.5; 0.4; 0.25), temperature (26 °C; 72 °C; 85 °C) and chemical composition of the leaching solution (pure water, mineralised water, ammonium nitrate solution). Firstly, the database is used to calculate the leaching kinetics of the cementitious materials. Secondly, a simplified model predicting the one-dimensional leaching kinetics for other water-to-cement ratios and temperature up to 85 °C is presented. 相似文献
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The effects of the compatibilization on the toughening of polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene triblock copolymer (SEBS) in a twin‐screw extruder were investigated. The compatibilizers used were an SEBS functionalized with maleic anhydride, a PP functionalized with acrylic acid, and a bifunctional compound, p‐phenylenediamine (PPD). The effects of the compatibilization were evaluated through the mechanical properties and by the determination of the phase morphology of the blends by scanning electron microscopy. Reactive compatibilized blends show up to a 30‐fold increase in impact strength compared to neat PP, which was likely to have been due to the reaction of the bifunctional compound (PPD) with the acid acrylic and maleic anhydride groups, which rendered both morphological and mechanical stability to these blends. The addition of the PPD to the blends significantly changed their phase morphologies, leading to larger dispersed particles' average diameters, probably due to the morphological stabilization at the initial processing steps during extrusion, with the occurrence of the chemical reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1081–1094, 2003 相似文献
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Indoor as well as outdoor air quality and their limiting values remain a major problem to our present-day society.This paper addresses the modeling of the decomposition process of nitrogen monoxide (NO) on reactive concrete surfaces under the controlled exposition of a UV source. Within this model the external mass transfer of the pollutant and the internal molecule diffusion-reaction were considered. A first-order kinetics equation is derived with respect to the NO concentration and a site-competitive adsorption between NO/NO2 and water molecules, resulting in a dependence of the reaction kinetics on the relative humidity. Using the proposed model, a reaction rate constant k and an adsorption equilibrium constant Kd can be derived which describe an active paving stone accurately. Experimental results from a self-developed photoreactor with continuous flow mode were used to validate the proposed kinetic expression. Furthermore, the effect of variations in process conditions such as irradiance and relative humidity on the two constants k and Kd is investigated. All modeling work provides a sound foundation for the translation of this process to real outside conditions. In this regard an upcoming project in a Dutch city is described in brief. 相似文献
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硫氰酸锰及其相关衍生物的合成及化学表征 总被引:1,自引:0,他引:1
合成了金属有机配合物非线性光学晶体硫氰酸汞锰,及其相关衍生物,二二甲亚砜合硫氰酸汞锰,乙二醇一甲醚合硫氰酸汞锰,二水合二N,N-二甲基乙酰胺合硫氰酸汞锰,二水合二N-甲基-α-吡咯烷酮合硫氰酸汞锰。采用元素分析,红外光谱以及紫外-可见-近红外透央求我谱分析对其进行了化学表征。 相似文献
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采用Sol-gel法制备了PbZr0.52Ti0.48O3 (PZT)薄膜,并研究了(SrZrO3)10(SrTiO3)90((SZO)10(STO)90)缓冲层对PZT薄膜结晶和性能的影响.X射线衍射(XRD)结果表明:(SZO)10(STO)90缓冲层对PZT薄膜结晶有取向诱导作用,由(SZO)10(STO)90诱导的PZT薄膜有很强的(111)择优取向,缓冲层将PZT薄膜的取向度α由45.0%提高到了90.1%以上;PZT的(111)择优取向提高了薄膜的电性能,使剩余极化强度Pr从26.8 μC/cm2增大到38.8 μC/cm2. 相似文献
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Tricalcium phosphate (TCP) based biomaterials are excellent candidates in hard tissue engineering due to their similarity to the natural bone composition and outstanding properties. The presence of additives such as (Mg2+, Zn 2+, F−, CO32− and/or SiO4−) in solid solution in the structure of TCP, affects the stability of its different polymorphs and therefore the properties of TCP based biomaterials. It is known that the incorporation of zinc in TCP in the non-toxic level stimulates bone growth and its mineralization, hence its interest. Nevertheless its effect on phase assemblage and microstructure evolution has not been clearly established. The main purpose of this study was to synthesize TCP and zinc doped monophasic/biphasic α/β-TCP dense biomaterials, by solid-state sintering process, with different ZnO contents and controlled phase proportions and microstructure on the final material. The effect of ZnO content and sintering temperature on phase assemblage, densification and microstructural evolution has been investigated. 相似文献
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This investigation considers a quantitative procedure for determining the values of critical process parameters in melt spinning to optimize the qualities of denier, tenacity, breaking elongation, and denier variance in as‐spun polypropylene yarn. An orthogonal array in the Taguchi method defines the minimum set of parameter‐level combinations that are experimentally tested. The significant process parameters, namely the third extruder barrel temperature, spinning temperature, metering pump speed, and take‐up velocity, are identified on the basis of the analysis of variance and F test. After a confirmation experiment is conducted to ensure the reproducibility of the experimental results, the back‐propagation neural network establishes a continuous system linking 10 process parameters and four qualities. The technique for order preference by similarity to an ideal solution can be used to obtain a performance measure for assessing multiple qualities. The genetic algorithm attempts to find parameter values for optimizing the quality performance, including the denier, tenacity, breaking elongation, and denier variance. Finally, the experimental results demonstrate that the smallest denier, largest tenacity, smallest breaking elongation, and second smallest denier variance of as‐spun polypropylene yarn can be achieved with the proposed approach in melt spinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2532–2541, 2006 相似文献
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Plasma pretreatment has been used to generate reactive radicals and oxygenated groups on polymer surfaces for graft polymerization. The polymer substrates studied were composed of a polypropylene–polyethylene (PP–PE) copolymer, which was predominantly PP, and also contained blended ethylene–propylene rubber (EPR) as either about 15 or about 60 mol %. A pure PP substrate was also studied for comparison. The grafted polymer was polystyrene (PS). Raman microspectroscopic 2‐dimensional mapping was used to elucidate the role of crystallinity and EPR in the plasma treatment and graft polymerization process. It was found that the plasma pretreatment favored the EPR component of the substrate and the graft yield was related to the EPR content. Crystallinity seemed to have a much less significant effect on the grafting reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1643–1652, 2003 相似文献
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Renata Tilova Antonina Kozowska Roman Kozowski David Hughes 《Cement and Concrete Research》2009,39(10):950-956
Mercury porosimetry, water vapour and nitrogen adsorption were used to follow the hydration of Roman cements — belite cements calcined at low temperature. Generally, unimodal distribution of pore sizes was observed, with the threshold pore width decreasing considerably with increasing curing time. An open porous structure with the threshold pore diameter between 0.2 and 0.8 μm and the specific surface area not exceeding 20 m2/g was produced at early ages when quick growth of the C–A–H phases is observed. The surface area reached up to 120 m2/g and the threshold pore width shifted to around 0.02 μm when the subsequent formation of C–S–H gel filled the larger pores. Both mercury porosimetry and water vapour adsorption were found to be capable of following the progress of hydration of the Roman cements with high reliability at least for a comparative evaluation of historic Roman cement mortars and repair materials used in restoration projects. 相似文献