Application of Spectroscopic Techniques to the Structural Analysis of Petroleum

INTRODUCTION

Petroleum, in the form of liquid oil or the solid asphalt, has been known for thousands of years (Speight, 1991) but, preceding the Industrial Revolution of the 19th century, its true potential was not realized. However, the advent of the Industrial Revolution caused man to turn from wood and coal to petroleum as the main source of liquid fuels. Furthermore, with the onset of the 20th century and the emergence of a technologically oriented society which has focused on the development of the automobile and the airplane, further uses have been found for petroleum products. Vast industries have emerged which rely upon the conversion of petroleum to a variety of by-products, and further uses for petroleumderived materials are still being addressed.     

芦荟中芦荟苷的结构表征及光谱分析

芦荟以其丰富的多糖、蛋白质、氨基酸、维生素、活性酶及对人体有益的微量元素被广泛用于各个领域。然而其主要活性成分芦荟苷同时也是一种致敏成分,更有甚者可能会引起严重的过敏反应。将红外、拉曼光谱应用于芦荟苷结构的表征,并将密度泛函数理论应用到理论计算中,利用B3LYP/6-31G(d)基组分析振动,可以更好地理解芦荟苷分子的振动频率。通过比较溶液的酸碱性以及最佳溶剂,最终选定在中性条件下,水作为溶剂为最佳实验条件,测定芦荟苷的检测限可以达到5 ppm的水平,为芦荟苷含量的快速检测奠定了理论基础。     

共振光谱技术在分析空间非均质物质上的应用(英文)

pacc:0765Thispaperdemonstratesthreevibrational spectroscopictechniquesandtheirapplicationsin characterizationofspatiallyheterogamousmateri als,namelystep-scanphasemodulationFTIR photoacousticspectroscopy(S2MPAS),visible(confocal)Ramanmicroscopy(CRM)andF…     

由槐米中提取槲皮素的光谱学表征

从槐树(Sophara Japonica L.)的花蕾(槐米)中提取芦丁,再在酸性条件下由芦丁直接水解得到槲皮素,采用UV,IR,ESI-MSn[质谱(电喷雾电离源)],1H,13C,DEPT(无畸变极化转移增益法)和1H-1HCOSY(氢-氢化学位移相关谱),HSQC(异核单量子相关谱),HMBC(异核多键相关谱)二维核磁技术对槲皮素进行了结构鉴定.     

Application and New Developments in Fluorescence Spectroscopic Techniques in Studying Individual Molecules

Abstract

Techniques based on fluorescence have played a variety of roles in chemistry, physics, spectroscopy, medicine, nanotechnology, and biotechnology due to their high selectivity, sensitivity, simplicity, and fastness in spectroscopic and imaging measurements. While detecting fluorescence from individual molecules by fluorescence‐based techniques, poor signal, limited lifespan of fluorophores, trade‐off between time resolution, and the level of detail of information were few major concerns. Ultrasensitive detectors permit the combination of the high time resolution of single photon counting devices with the large field of view and spectral resolution allowed by two‐dimensional detectors. Photobleaching and on‐off blinking of fluorophores can be improved dramatically by chemical modifications or changing the reagents. New ways of controlling local fields such as optic, electric, magnetic, chemical, or biochemical environments take advantage of the noninvasiveness and high temporal and spatial resolution of single‐molecule fluorescence (SMF) to get a direct feedback of events at the nanometer scale in various domains of research. Some of the applications and new developments in fluorescence spectroscopic techniques in detecting, investigating, and/or manipulating individual molecules have been discussed.     

Fracture Characterization with NMR Spectroscopic Techniques

Determination of suitable techniques and analyses that can be implemented by NMR well logging can greatly improve the characterization of underground petroleum reservoirs and aquifers. In this paper, the feasibility for using various NMR methods for detection and characterization of fractures is explored. Analyses of experimental data obtained with a variety of samples are presented. It is shown that relaxation contrasts are useful for separating the signal contributions from fluids in the fractures and the porous matrix, and that relaxation weighting can be used in combination with other NMR techniques for enhancing fracture characterization.     

高温Raman光谱测试技术进展

高温Ｒａｍａｎ谱是现代揭示物质分子结构的主要手段之一。上海市钢铁冶金新技术开发应用到为能在高温下对冶金熔体等物质进行Ｒａｍａｎ光谱的测定。研究分析了国际上的各种测定高温Ｒａｍａｎ光谱的方法,实施了对ＪＹ Ｕ１０００型Ｒａｍａｎ光谱仪的改造,以及提出阱一步提高谱仪高温测定性能的方案。     

近红外光谱判别分析滤波器的设计与应用

近红外光谱(NIRS)在定量和判别分析中已得到广泛应用,化学计量学在其中发挥了重要作用,但仍需要建立基于新原理的方法,简化数据处理和建模过程,使近红外光谱分析更加方便、更加快速.多元光学计算(M O C)技术通过设计合适的光学滤波器可以在光谱测量的同时,根据光谱的整体形状得到定性定量结果.作为一种新的测量和计算方式,近...     

卡巴他赛结构确证的波谱学研究

用红外吸收光谱、紫外吸收光谱、核磁共振（NMR）波谱（包含¹H NMR、¹³C NMR、DEPT-135、COSY、HSQC和HMBC）、质谱、差示扫描量热分析、X-射线粉末衍射和元素分析等方法对卡巴他赛原料药精制品进行了结构确证,对其所有的¹H和¹³C NMR信号进行了归属,同时讨论了质谱主要碎片离子可能的裂解方式和红外特征吸收峰所对应的官能团的振动形式,通过多种波谱技术结合确证了卡巴他赛的结构．     

Comparing Spectroscopic Techniques for the Measurement of Phosphorus in Wastewater

Animal and plant wastes contain recoverable phosphorus that can be repurposed as fertilizer. Ultraviolet-visible spectroscopy and inductively coupled plasma optical emission spectroscopy are compared for the measurement of phosphorus in salt solutions, then wastes. There is no impact of nitrate or chloride on phosphate measurements by ultraviolet-visible spectroscopy, but high concentrations interfere with phosphorus measurement by inductively coupled plasma optical emission spectroscopy. Greenhouse and swine waste can be analyzed by either technique, but more dilution is required for analysis by ultraviolet-visible spectroscopy and for swine waste. Swine waste has ～8 times more phosphorus than greenhouse waste and is the more viable waste source for phosphorus recovery.     

双层PLS算法及其在近红外光谱分析中的应用

针对近红外光谱数据局部效应显著,变量个数多,且彼此间常存在严重的复共线性,并与样品组分含量呈非线性关系,构建了一种双层非线性偏最小二乘回归 (DNPLSR)算法。它将非线性回归和偏最小二 乘(PLS)相结合,先在外层由PLS从样本数据中提取成分,并实现每对成分间的非线性映射,再在内层实施PLS算法,将外层因变量成分的拟合误差反馈计算转换权向量的增量,进一步修正转换权向量,以使外层所提取的成分对因变量具有更优的解释能力。最后,将该法应用于80个谷物样品的水组分含量与其近红外光谱的定量关系建模,效果良好,显示出很强的学习能力,所建模型的预报性能也优于其他方法。     

黄素体系电子转移过程光谱研究

黄素类物质在生物体内广泛存在,是许多电子转移反应的活性中心,也是电子传递链的重要组成部分。其受到光照激发后引起的电子转移,是许多生命过程的基础与起始步骤。特别地,一种名为隐花色素的黄素蛋白在光激发后经一系列电子转移形成自旋相关自由基对,被认为是最有可能的生物磁敏物质,更使黄素体系电子转移过程的动力学,特别是自旋动力学过程倍受关注。对黄素电子转移过程及相关机理进行研究,有助于厘清多种生命过程的化学机理与影响因素。为此,科学界综合运用了多种仪器与测试手段,其中主要包括紫外-可见光谱,荧光光谱,瞬态吸收光谱,光化学诱导动态核极化（Photo-CIDNP）技术等。通过多年的研究,对黄素在生物体内的作用机理与电子转移过程的认识经历了由浅入深,不断深入的过程。紫外-可见光谱（UV-Vis）主要用于研究黄素系统中的电子激发,自旋动力学和电子转移。结合理论计算,UV-Vis还可以识别电子转移中涉及的基团并进行定量分析。荧光光谱可以识别电子受激发的物质,在反应过程中观察黄素和半醌中间体的产生和消耗,并确定其氧化还原和质子化状态。瞬态吸收光谱适于观测反应过程中出现的短寿命物种,其中飞秒泵浦探测技术的引入大大提高了观测的时间分辨率,并且可以通过光谱特征区分单重态和三重态的自由基对。光化学诱导动态核极化核磁共振（NMR）可以直接观察电子-核自旋动力学过程。磁场依赖性photo-CIDNP NMR揭示了控制单重态与三重态互变的因素,并提出了生物地磁导航可能依赖的化学机制。腔吸收与单分子光谱的运用,从技术上提高了实验装置的灵敏度并降低检测限。主要介绍黄素体系电子转移过程研究所运用的各种光谱手段与取得的成果,并展望其未来。     

氧化锌叶片状纳米晶的结构和光谱特性

熔盐法对sol-gel法生成的前驱物处理合成新颖的叶片状的氧化锌纳米结构,TEM照片显示其长度300-500nm,宽度为50-80nm,两头尖端约呈25°夹角,形状基本沿中轴呈中心对称。其生长过程进行了研究:弯曲了的ZnO纳米棒闭合形成框架结构,框架内沿中轴方向并排生长的ZnO纳米线填满框架内的空隙形成叶片状的氧化锌纳米结构。Raman谱测量发现该结构是晶化的六角相氧化锌。对叶片状的氧化锌的声子限制效应进行了研究,并与纳米颗粒氧化锌予以比较。435cm-1的E2峰的Fano不对称具有正的Fano耦合系数。发现在585nm处出现光致发光峰,归于ZnO纳米结构中氧缺陷的作用。     

近红外光谱技术在烟草领域的应用进展

本文对国内外NIR在烟草行业的研究、应用作了较详细的综述.国内相关研究起步较晚,近几年来,涌现了大量的有关NIR在烟草行业中的应用研究报告,研究的范围也渐趋广泛,NIR光谱技术是一种测定烟草整个制品的技术,值得深入研究.引用文献48篇.     

Synthesis and Spectroscopic Structural Elucidation of New Quinoxaline Derivatives

A quinoxaline‐2,3‐dione derivative was synthesized, and its chemical structure was determined through spectral analysis. Alkylation of this compound under phase transfer catalysis (PTC) conditions yielded monoalkylated and diakylated adducts. The monolalkylation process was shown to be regioselective occurring on the quinoxalic nitrogen atom rather than on its pyrazolic analogue. The full characterization of the synthesized compounds was studied by concerted use of NMR and MS techniques. Assignments of proton and carbon atoms were achieved through analysis of the 1D ¹H and ¹³C NMR spectra combined with homo‐ and hetero-nuclear 2D NMR experiments. Determination of the alkylation site was achieved through long‐range proton–carbon coupling correlations spectroscopy.     

现代近红外光谱技术及应用进展

简要介绍了现代近红外光谱的发展、技术特点和测量原理 ,对近年来近红外光谱仪器、化学计量学方法及软件和应用的进展情况及我们在这几个方面开展的工作进行了简要介绍     

The Application of 2D NMR Techniques in the Structural Assignment of the Diterpenoid Alkaloid,Delphinine

The two dimensional inverse detected heteronuclear correlation experiment HMQC and the homonuclear correlation experiments COSY and ROESY were performed on the natural alkaloid, delphinine enabling complete assignments of the ¹H and ¹³C spectra. The stereochemistry of ring A and B have been determined in solution. The results suggest that the application of direct correlation multipulse NMR techniques allows for unambiguous structural assignment of delphinine.     

高硫肥煤碳结构研究与光谱学表征

煤结构是煤化学的重要研究内容,优质肥煤在我国属于稀缺炼焦煤种。碳是煤结构的基本骨架,是构成煤中有机质及形成焦炭的主要元素。研究高硫肥煤中的碳结构对认知肥煤结构与性质,提高低品质炼焦煤利用效率具有重要意义。采集并制备山东东滩（DT）和山西水峪（SY）、霍州（HZ）、高阳（GY）四个矿区的肥煤样品,利用X-射线衍射（XRD）、傅里叶变换红外光谱（FTIR）以及 X-射线光电子能谱（XPS）对煤中碳结构进行谱学表征和联合解析,结合煤质分析结果,计算不同肥煤样品的碳结构参数。研究结果表明：SY,HZ,GY和DT四种肥煤的芳香度f_a-XRD依次增大,芳香层片的延展度L_c和堆垛高度L_a依次减小,山西煤的芳香碳结构层片在排列规整度和芳香环缩合程度上强于东滩煤。DT和GY煤中芳香烃结构主要以苯环五取代、苯环四取代和苯环三取代形式存在,SY与HZ煤中芳香结构以苯环二取代和苯环四取代为主。DT和GY煤含有较多的支链和较高的芳环缩合度。四种肥煤中脂肪结构均是以亚甲基为主,DT,SY,HZ和GY煤的亚甲基占脂肪结构的比例分别为46.27%,48.89%,44.21%和41.85%,煤中含有较多的烷基侧链。GY与DT煤中甲基含量略高于次甲基,SY和HZ煤则相反,这主要与不同煤样在成烃期间长脂肪族结构发生断裂的程度有关。SY,HZ,GY和DT煤的芳碳率分别为0.83,0.81,0.74和0.68,芳氢率分别为0.51,0.43,0.34和0.29,煤中芳构化程度依次减小,芳香环缩合度依次升高。DT和HZ煤的氧化程度较高,DT煤含有较多的C-O结构,判断DT煤中存在较多不易被热分解或不易起化学反应的非活性氧。     

Spectroscopic Approach to the Analysis of High Current Arcs in SF6

Spectroscopic observations were carried out on transient free-burning arcs drawn by separating copper/tungsten electrodes in SF6 gas. The peak value of the arc current was varied up to 60 kA. A new optical method was developed to measure temperature and pressure profiles of the arc taking the magnetic pinch force into account. The arc voltage calculated from the obtained temperature and pressure profiles agreed well with electrical measurements. The results made it clear that the composition of the arc changes significantly at the critical instantaneous current of 10 kA. Above 10 kA the arc is composed of the electrode vapor, while it contains SF6 gas below 10 kA.