核磁共振技术在生命科学中的应用

在过去的50年中,核磁共振技术已经成为应用广泛的一种分析测量工具.由于具有无侵入、无破坏和测量信息丰富等诸多优点,核磁共振技术对于生命科学的研究工作者极具吸引力.本文对核磁共振技术在生命科学中的主要应用进行了归纳总结.由此不难看出,核磁共振技术已经渗透到生命科学领域的多个学科分支,显示出了良好的应用前景.     

核磁共振联用技术在代谢物结构研究中的应用

核磁共振联用技术是体内药物代谢产物结构鉴定的强大工具。本文综述固相萃取-核磁共振、液相色谱-核磁共振、液相色谱-核磁共振-质谱等联用技术在研究生物样品中代谢物结构的应用。     

核磁共振技术在植物代谢研究中的应用

基于核磁共振技术(Nuclear Magnetic Resonance,NMR)和模式识别技术的代谢组学研究是近几年发展起来的一种新的组学技术。该文简要综述核磁共振技术用于植物代谢研究的实验设计、图谱的获取、模式识别技术及其最新应用。     

固体高分辨核磁共振技术在有机固体研究中的应用

有机固体研究是一门新兴的多学科交叉的材料科学,本文介绍了固体高分辨核磁共振技术在有机固体研究中的常用的有效的实验方法,概述了近年来国外用固体核磁共振技术在有机固体的结构研究、分子复合物研究、化学动力学研究及晶型研究等方面的部分研究成果。     

核磁共振方法在高分子聚合物方面的应用

综述了近年来核磁共振波谱技术在高分子材料方面的应用,主要从液体核磁共振-固体核磁共振-核磁共振二维谱等技术方面进行了论述.并且给出了该技术的一些具体应用实例.如核磁共振碳谱对丁二烯序列结构的研究;乙丙共聚物的研究,二维相关谱对苯乙烯和聚乙烯甲基醚序列结构的测定等.NMR在高分子性能表征方面的应用前景广阔.     

虚拟仪器技术及其在电子及物理实验中的应用

介绍了虚拟仪器的基本概念及其在国内外的发展状况,并在分析其结构特点的基础上,时其在电子及物理实验中的应用的开发作了有益的探讨.     

高分辨固体核磁共振技术在材料化学研究中的应用

近年来,高分辨固体核磁共振技术(SSNMR)发展迅速,其在化学材料研究领域的应用价值日益显现。本文第一部分简述了化学研究中常用的SSNMR脉冲高分辨技术,包括同核和异核去偶技术以及偶极重聚技术等。第二部分结合具体的实验方法和实例,重点介绍SSNMR技术在材料研究中的应用。首先,使用一维谱实验、二维化学位移相关谱实验来实现分子化学结构和聚集态结构的研究;然后,通过同核偶极偶合常数的测量来计算原子核间的距离信息;此外,交叉极化定量实验可以实现样品体系结构和组分的定量表征;最后,通过对异核偶极偶合常数的测量、线型分析以及弛豫时间的测量等方法来实现固体材料分子动力学行为的研究。     

用Autosorb-1物理吸附分析仪测定矿物材料孔结构的应用研究

文章概述了孔分布的计算方法,对分子筛试样测试结果的分析表明分子民径１２Ａ和３１Ａ附近有重要吸附贡献,属典型的中孔基体,微孔物质的混合物。最后给出了海泡石等四种矿物材料孔结构的测定结果。     

岩石锚杆基础在山区基础施工中的应用

岩石锚杆基础是通过锚杆与岩石的结合特性来承载上部杆塔的下压力和上拔力,现简要介绍了岩石锚杆基础的应用特点及施工流程,并对具体的施工方案进行了研究探讨.     

核磁共振技术及应用研讨会在京圆满落幕

9月25日,由中国仪器仪表学会主办,中国仪器仪表学会科学仪器学术会工作委员会、《现代科学仪器》编辑部承办的＂核磁共振技术及应用研讨会＂作为北京第二十五届测量控制与仪器仪表学术会暨展览会的子课题,在北京中国国际展览中心举行并圆满落幕。本次会议由《现代科学仪器》主编胡柏顺先生主持并致开幕词。他说,本次会议旨在总结交流国内外核磁共振技术及应用进展,国内核磁仪器研制情况及存在问题,共议发展国产核磁仪器的措施和建议。大会邀请了相关的核磁共振领域的知名专家学者做专题报告,如中科院武汉物理与数学研究所的叶朝辉院士、     

核磁共振谱仪锁线故障分析与排除

对德国ＢＲＵＫＥＲ公司ＡＣ、ＡＭ系列核磁共振谱仪锁线故障进行了分类，分析了各故障的产生原因，阐述了排除过程。     

Miniature nuclear magnetic resonance spectrometer using a partially enclosed permanent magnet

Conventional nuclear magnetic resonance (NMR) instruments are limited by their large volume volume. A miniature NMR spectrometer is reported using a partially enclosed miniature permanent magnet and a low-cost solenoid microcoil probe. The miniature NMR spectrometer uses a sample volume smaller than conventional NMR spectrometers by a factor of 1000. Transverse relaxation times were obtained by the miniature spectrometer using 150?nL of 40?mM copper sulfate, 1?M aqueous sucrose, absolute ethanol, and deionized water. The results demonstrate that high signal-to-noise ratios were obtained. The results were also compared with a commercial NMR spectrometer and suitable accuracy of the laboratory-constructed device was obtained. The miniature NMR spectrometer was employed for the characterization of heated soybean oil. The reported miniature NMR spectrometer is anticipated to have applications for onsite detection.     

高场NMR谱仪的应用和进展简介

高场核磁共振谱仪具有高灵敏度和高分辨率等优点,能在接近生理条件下,测定生物大分子的溶液结构。本文介绍了高场核磁共振谱仪在结构生物学中的一些应用,以及核磁共振谱仪的一些进展。     

实验低场脉冲核磁共振仪数据接收与处理

低场脉冲核磁共振系统接收到的信号信噪比低，解谱结果对系统噪声敏感。针对我们自行研制的实验低场脉冲核磁共振仪，以小波分析等现代信号处理理论为基础，提出了一些数据接收与处理的方法，在有效抑制噪声的基础上准确提取回波信号峰值。通过多指数反演解谱算法获得磁共振信号的正谱分布，从而进行样品的定量分析。     

Detailed characterisation of sulphur and nitrogen components in a multifunctional,ashless lubricant additive by spectroscopic and chromatographic techniques

The work reported here used infrared (IR), multinuclear nuclear magnetic resonance (NMR), and chromatographic techniques to identify and characterise a commercial sulphur‐ and nitrogen‐containing ashless multifunctional additive. The proper assignment of signals in the ¹H/¹³C NMR and IR spectra of the sample has facilitated the identification of different types of sulphur‐ and nitrogen‐containing components. The methodology involves investigation by NMR and IR spectroscopies, thin‐layer chromatography (TLC) and high‐performance liquid chromatogaphy (HPLC) techniques to elucidate the types of components present. This requires the generation of NMR and IR spectral data for standard compounds of alkyl sulphides with different sulphur content and alkyl chain, and nitrogen and sulphur components such as thiadiazole, imidazoline, triazole, etc., and spectral comparison with the spectra of the unknown sample. Further, these components have been separated by silica/alumina column chromatographic and preparative TLC techniques and subsequently analysed for their exact chemical structure by spectroscopic techniques. The combined spectroscopic and chromatographic analyses have yielded the presence of four types of components: di‐t‐octyl polysulphide, di‐t‐octyl thiadiazole, a component containing amine ether functionality, and alkyl amine salts of mono/dialkyl phosphoric acid.     

基于噪声拟合的核磁共振二维谱反演新方法

针对现有二维反演算法对噪声敏感或过度依赖于对噪声的估计的问题,提出了一种基于噪声拟合的核磁共振二维谱反演新方法.首先,使用小波滤波进行噪声提取;然后将噪声分布按照高斯白噪声的数学模型进行拟合,获取噪声方差;最后依据制定的新的停机准则和进化算法进行拟合,拟合残差与估计的噪声水平相当或最接近时,迭代停止并得到二维谱.通过使用该算法对不同信噪比的仿真数据和多组实验采集数据进行处理后发现,该算法具有很高的鲁棒性和准确性.这种新的反演算法能够满足不同应用领域、不同信噪比数据的反演要求,具有很高的实际应用价值.     

Dependence of the friction process on the molecular structure and architecture of thin polymer films

The frictional properties of a homologous series of poly(n-alkyl methacrylates) (PnAMA) and a series of poly(methyl methacrylate) (PMMA) films, cast from a variety of solvents, are characterized. The choice of polymer film was driven by the consideration of the possible mechanisms for the accommodation of a macroscopically applied shear stress by molecular entities. Two possible mechanisms are proposed: (i) the relative flexibility of the polymer backbone chain. For this purpose the PnAMAs have been chosen. By varying the length of the substituent chain, the relative molecular freedom around the backbone chain is altered. These molecular differences are sensed in the frictional properties at the macroscopic level, and (ii) the molecular organization is also proposed to be a factor in determining the friction response of a particular polymer film. For this purpose, the frictional properties of PMMA films cast from different solvents are investigated. There is observed to be a strong influence of the molecular organization on the frictional properties of the solvent cast PMMA films. The molecular probe employed to characterize the molecular environment is vibrational spectroscopy. Conformationally sensitive vibrational modes are used to determine the relative flexibility of the backbone chain and the organization of the chain network.     

Structure elucidation capabilities on typical pharmaceutical drugs by new nuclear magnetic resonance technology: a 400 MHz high-temperature superconducting power-driven magnet NMR system

Nuclear magnetic resonance (NMR) is a powerful technique for the structure elucidation of organic molecules and significantly important in the pharmaceutical industry supporting the discovery and development of drug substances or active pharmaceutical ingredients (APIs). Following an initial study and assessment of a prototype NMR instrument with a high-temperature superconducting (HTS) power-driven magnet of 9.4?T (400?MHz for ¹H observation) operating with standard commercial electronics and probes, we tested the instrument with three compounds representing typical pharmaceutical drugs. We compared results from two probes and shimstacks with different geometries (broadband fluorine observe (BBFO) with Bruker orthogonal shim system-3 (BOSS3) and Bruker quattro nucleus probe (QNP) with BOSS1 shims) testing standard one-dimensional (1D) NMR experiments including selective excitation experiments, and two-dimensional (2D) homonuclear and heteronuclear experiments for the purposes of evaluating the equipment for structure elucidation capabilities. In our initial study on cinacalcet HCl, only the 1D ¹H experiment showed a loss of resolution when using the longer coiled BBFO probe with the BOSS3 shims compared to the shorter coiled QNP probe with BOSS1 shims. The selective excitation experiments using the cinacalcet HCl were successful. Our characterization of 1D (¹H, ¹³C, ¹⁹F) and 2D (¹H-¹H and ¹H-¹³C) NMR experiments for compounds I and II with the two probes and shimstacks indicated no significance differences. Overall, these results are satisfactory with the HTS magnet at the field of 9.4?T for the structural elucidation work of standard pharmaceutical compounds. This new technology has the advantage of being able to locate the HTS NMR magnet system in any chemistry or analytical laboratory where the samples are produced, facilitating rapid analysis with minor needs from the facilities and without cryogenic liquids.     

激光共振电离质谱及其在核技术中的应用

激光共振电离质谱是激光共振电离技术和质谱技术相结合的一种新型质谱分析技术,具有高元素选择性和高灵敏度的特点,能有效克服商业质谱仪存在的同量异位素干扰难题。为满足复杂基体干扰下超痕量核素分析测量的需求,实验室研制了一台基于磁 电双聚焦质量分析器的激光共振电离质谱仪。该装置的质量分析器采用正向Nier-Johnson型双聚焦结构,由柱形静电分析器和扇形磁质量分析器组成。本文介绍了仪器质量分析器的结构和理论参数,并对其进行理论仿真与实验测试。结果表明,该仪器实现了方向和能量双方向聚焦,具有较小的高阶像差,仪器的水平方向放大率为0.78,质量色散达到500 mm,当源狭缝宽度0.25 mm、探测器入口狭缝宽度0.65 mm时,质量分辨率（10%峰谷）达到580左右,接近质量分辨率的理论极限605。最后,介绍了本实验室利用该仪器开展的分析测量工作,展示了该装置在强同量异位素干扰下超痕量核素测量方面的部分应用情况。