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杂原子进入分子筛骨架结构的波谱学判据 总被引:7,自引:0,他引:7
概括了杂原子取代的分子筛内骨架杂原子的波谱学鉴定方法。根据杂原子进入骨架后所引起的晶体结构、表面酸性、电子跃迁规律、配位环境等微观性质的变化,重点讨论了XRD、FT-IR、DR UV-Vis、Raman、MAS-NMR、XAFS、ESR和XPS等波谱学方法在鉴别骨架杂原子时的应用原理和方法。 相似文献
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DNA是主要的遗传物质.无论是在包装成异染色质的静息状态下,还是在复制、重组和转录等活跃状态下, DNA往往都与其他分子组成复合体.这些复合体与DNA保护、扩增和利用密切相关.另一方面,由于序列和结构的高度可变性, DNA逐渐被人为开发成适配体用于识别其他分子.阐明这些体系中DNA与其他分子形成的复合体结构,可以认识生命活动基本原理,并为基因改造、疾病治疗和生物安全等应用研究提供关键信息.核磁共振波谱学(NMR)是测定分子结构的主要方法之一,能在近生理条件下获得结构、作用位点以及动力学等信息.本文聚焦DNA及其与其他分子形成复合体结构这一体系,对我国学者近十年来利用NMR方法开展的工作进行介绍,并探讨NMR方法在该领域的发展方向. 相似文献
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《分析化学》2006,34(9):53-53
《有机化合物结构鉴定与有机波谱学》英(加增补)版,“Structural Identification of Organic Compounds with Spectroscopic Techniques”近期已经由WILEY-VCH出版。书中对核磁共振、质谱、红外和拉曼光谱的基础理论作了深入的阐述,详细地阐明了有机化合物的谱图解析方法,汇集了波谱学领域研究和应用的最新进展,如脉冲场梯度技术、液相色谱-核磁共振联用、扩散排序谱技术等。该书是波谱学基础理论与实际应用相结合的仪器分析类的工具书,也可作为研究生的教材。作宁永成教授在该书中融入和归纳了解析谱图的规律和心得。 相似文献
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A novel, rapid and reliable method has been established for the determination of methanol using sodium nitroprusside as a spectroscopic probe. This method indicates that the sodium nitroprusside can react with the methanol to form a colored product in the basic solution. The absorbance of the product is measured at the maximal absorption wavelength of 481 nm, and the amount of methanol can be calculated based on this absorbance. A good linear relationship of the concentration of methanol versus absorbance is observed with a linear range of 0.02‐6.0 mg mL?1. The linear regression equation is A = 0.02484 + 0.29457C (mg mL?1), with a correlation coefficient of 0.9991. The detection limit (3σ/k) is 0.012 mg mL?1, while its R.S.D. is 1.5% and the recovery rate is 97.5‐102.5%. The parameters with regard to determination are optimized, and the reaction mechanism is discussed. This method has been successfully applied to determine methanol in variety of samples. Analytical results obtained by this new method were very gratifying. 相似文献
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《Journal of Coordination Chemistry》2012,65(2):77-83
The structure and infrared spectrum of sodium 3,4-diaminobenzoate have been studied. The sodium salt crystallizes in the orthorhombic system, space group Pcab with a = 6.1940(10), b = 14.285(3), c = 21.348(4) Å, and Z = 8. The compound is polymeric in which Na ions are coordinated to six oxygen atoms, with Na-O distances ranging from 2.3380(14)-2.5856(18) Å. The compound dehydrates at 340 K and is decomposed at 485 K. IR spectra of the salt are discussed. 相似文献
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LiZHANG NaLI FengLinZHAO KeAnLI 《中国化学快报》2004,15(6):671-674
The interaction between heparin and neutral red was investigated by molecular spectroscopic methods. The change of all spectra suggested that positively charged neutral red had interacted with negatively charged heparin. The study of influence factors indicated that electrostatic force and hydrophobic bond might be involved in the interaction. The total binding number per disaccharide unit and intrinsic binding constant were obtained using Scatchard model. 相似文献
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The molecular recognition behavior of the chiral salen-metal complexes towards guest molecules, such as imidazole derivatives and amino-acid ester, was systematically investigated by means of circular dichroism (CD) spectra. The coordination numbers of the host-guest complexes as well as the recognition capability of the salen-metal complexes were explained by character and intensity analyses of the CD spectra. 相似文献
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《Analytical letters》2012,45(9):1037-1048
Abstract The first experiment in which stepwise photoionization of atoms is used for analytical purposes is reported. A detection limit of 12 pg/ml has been achieved for sodium in aqueous solutions. The results are compared with atomic fluorescence measurements. The potentialities of the new method are discussed. 相似文献
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光谱法与分子模拟对左旋紫草素和人血白蛋白键合作用的研究 总被引:4,自引:3,他引:1
采用荧光光谱法、紫外吸收光谱法和圆二色性光谱(CD)研究了模拟生理条件下左旋紫草素和人血清白蛋白(HSA)的相互作用,计算了反应的结合常数、结合位点数和热力学参数,并探讨了左旋紫草素对人血清白蛋白二级结构的影响.在温度为292、303、310和318 K时,根据Scatchard方程测得左旋紫草素和HSA的结合常数分别为3.118×10~6、0.249×10~6、0.112×10~6 和0.102×10~6 L·mol~(-1),结合位点数分别为1.308、1.094、1.026和1.018;焓变(ΔH)和熵变(ΔS)分别为-104.82 kJ·mol~(-1)、-238.18 J·mol~(-1)·K~(-1),左旋紫草素在人血清白蛋白上的结合位置与色氨酸残基间的距离为2.66 nm.分子模型研究表明,左旋紫草素与HSA在亚结构域ⅡA结合,二者间的作用力主要为疏水和氢键作用力.CD结果表明,左旋紫草素与HSA的键合使HSA中α-螺旋结构含量从55.80%降到52.31%. 相似文献
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超临界NaCl水溶液的分子动力学模拟 总被引:7,自引:0,他引:7
采用分子动力学模拟的方法对超临界NaCl水溶液的微观结构进行了研究.模拟发现在所研究超临界条件下,密度的变化比温度的变化对超临界NaCl水溶液的微观结构影响更大.温度及密度对Cl- H2O径向分布函数的影响比对Na+ H2O径向分布函数的影响要大.超临界条件下,各gNa+-Cl-在0.261 nm处出现峰值,表明Na+、Cl-之间发生了离子的缔合.超临界条件下,随温度增加,缔合作用增强;随密度增加,缔合作用减弱.本文工作为建立可适用于超临界条件下的电解质热力学模型提供了依据. 相似文献
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本文根据阿达玛变换的原理研制成一种双编码阿达玛变换光谱仪,与单编码及常规光谱仪相比,该仪器具有高信噪比、高输入和单检测器多通道同时检测的优点。试样分析表明:该仪器能用于荧光谱分析和原子线光谱分析。 相似文献