Principles of sampling,preparation and constituent selection for microphotometry in measurement of maturation of sedimentary organic matter

Samples may be obtained from outcrops, cuttings, cores, modern sediments and old collections. Coals, brown or grey siltstones and fine-grained sandstones generally yield the most satisfactory organic matter for maturation analysis, while red beds and evaporites are often barren. Shales with a high organic content are not especially desirable for optical studies of maturation because the organic matter is likely to be very fine-grained and high in pyrite. The whole rock or a concentrate of organic particles may be prepared for microscopical study, the former being preferred for analysis of solid bitumens and fluorescence study, the latter for measurement of vitrinite reflectance, microspore translucency and refractive index. Crushing, ultrasonic disintegration, handpicking, heavy liquid separation, flotation, settling, sieving and demineralization with HC1 and HF are used to concentrate organic particles. Preparations include polished rock slabs, concentrate briquettes and strew mounts. The constituents with the lowest maturation in a rock must be selected if maturation indigenous to the rock is to be measured. Organic matter that has been previously altered at its site of origin, reworked and altered during diagenesis, or redeposited from older rocks, must be excluded from consideration. The organic constituents are recognized most easily by reflected light microscopy. A combination of fluorescence and reflectance techniques is useful for low rank samples.     

Studies on haemoglobin from the Indian toad, Bufo melanostictus, by electron microscopy

Hæmoglobin from an amphibian, Bufo melanostictus, was studied by electron microscopy after metal shadowing and after negative staining with uranyl acetate. The effect of the electron stain on the protein was investigated by spectrophotometry. The sample was also characterized by alkali denaturation and sedimentation analysis. The results were compared to those of adult human hæmoglobin. Spectrophotometry of the sample showed characteristics similar to those of normal oxyhæmoglobin. The protein, like human adult hæmoglobin, was found to be completely alkali-labile. Ultracentrifugation of a freshly prepared sample showed a single symmetrical peak, an indication for the presence of a homogeneous component. The S⁰_20,W value (5.1) was found to be markedly higher than that of adult human hæmoglobin. With storage, however, the peak became asymmetrical suggesting the formation of a limited amount of a heavier component. The electron micrographs of the shadowed preparations revealed a characteristic shape and ultrastructure of the protein molecules and their average height was found to be 5.5 nm. The micrographs of the negatively stained samples showed many particles with a substructure similar to that of the shadowed molecules and a mean dimension of 6.1 nm, a number of dimers of average length 6.0 nm and overall width 3.6 nm, and many globules of average diameter 3.6 nm. These were interpreted as whole, half and quarter hæmoglobin molecules, respectively. Both techniques revealed at the most four subunits in a molecule. The structure of the subunits and their arrangement in the molecule were found to be essentially similar to those of normal human adult hæmoglobin, and could be interpreted in terms of the Perutz model. Spectrophotometry of the mixture of the protein and uranyl acetate showed that the protein becomes denatured with time and that the denaturation is due to the low pH (4.3) of the stain. Nevertheless, this study showed that by keeping the staining time very short, it is possible to obtain acceptable electron micrographs of small multi-unit protein molecules such as haemoglobin.     

高精度测量光学玻璃折射率的一种新方法

摘要: 准确测量光学玻璃的折射率已成为了保证光学系统成像质量非常重要的环节。本文介绍了光学玻璃折射率测试方法和国内外发展现状。提出了一种利用测量棱镜三个顶角所对应的三个最小偏向角的折射率测量新方法,该方法的特点是测量精度随被测光学玻璃的折射率增大而提高。在精度0.5²的测角仪上,折射率测量精度高于1x10-6。文中推导出了新方法的计算公式,并对精度做了理论分析。该方法由于测量精度高,有较好的应用前景。     

Refractometry of fungi

Immersion refractometry is based on matching the refractive index of the medium to that of the cytoplasm of the cell, in which case the latter will have minimum contrast in the phase contrast microscope and will practically disappear. The cytoplasm is then said to be at the match point with the medium. Since the refractive index of a solution is related to its concentration by the formula n - n_o =αC, the values for the refractive indices can be expressed in terms of the concentration of solids (g/100 ml) which in fact has been done throughout this work. The properties of a suitable immersion medium, its preparation and interpretation of numerical results have been discussed. Refractometric measurements were carried out on fungal hyphae and spores. The solid concentration in hyphae varies according to their age, physiological state and function. In general the highest values are found at sites of physiological activity, such as growth and reproduction, and may range from 11% to 30% of solid concentration. The solid concentration of mature, resting spores was found to be in the range of 45–54%, with the exception of a powdery mildew spores in which the concentration of solids was 30–32%. The germination of spores is preceded by a fall in the concentration of solids, and subsequent swelling before the emergence of the germ tube. When the solid concentration in pregerminating spore has fallen to about 20–30%, metabolic activity can take place and germination can occur.     

Problems and Solutions in 3-D Analysis of Phase Biological Objects by Optical Diffraction Tomography

Optical Diffraction Tomography is a technique for retrieving a 3-dimensional refractive index distribution from phase objects without destroying the structure of the samples. In the article we discuss the selection and implementation of full and limited angle version of tomographic reconstruction processes together with the analysis of different methods for gathering projections. We present two efficient implementations of full and limited angle tomographic systems including total processing paths and providing the examplary results of 3-D refractive index determination measurements of biological samples.     

Indirect measure of shale shear strength parameters by means of rock index tests through an optimized artificial neural network

Shear strength is one of the most important features in engineering design of geotechnical structures such as embankments, earth dams, tunnels and foundations. Shear strength parameters describe how rock material resists deformation induced by shear stress. Rock shear strength parameters are usually measured through laboratory tests, and these methods are destructive, time consuming and expensive. In addition, providing good-quality core samples is difficult especially in highly fractured and weathered rocks. This paper presents an indirect measure of shear strength parameters of shale by means of rock index tests. In this regard, 230 shale samples were collected from an excavation site in Malaysia and shear strength parameters of samples were obtained using triaxial compression test. Furthermore, rock index tests including dry density, point load index, Brazilian tensile strength, ultrasonic velocity, and Schmidt hammer test were conducted for each sample. A particle swarm optimization-artificial neural network (PSO-ANN) integrated model was developed by setting the results of rock index tests as inputs and shear strength parameters as outputs of the model. The obtained correlation of determination of 0.966 and 0.944 for training and testing datasets show the applicability of the proposed model to predict shale shear strength parameters with high accuracy.     

原子光谱分析食品中有毒元素的前处理方法

本文综述原子光谱分析中应用的各种前处理方法,包括干法灰化法、湿法消化法、微波消解法、直接固体进样法、悬浮液进样法、稀释法与水浴蒸干法等在食品中有毒元素分析中的应用情况。此外,还介绍超声波辅助提取、同位素稀释法、紫外光解法等新方法的进展。引用文献56篇。     

Fluorescent resolution target for super-resolution microscopy

We report methods of near‐field infrared microscopy with transient optically induced probes. The first technique – a transient aperture (TA) – uses photoinduced reflectivity in semiconductors to generate a relatively large transient mirror (TM) with a small aperture at its centre. We report the optical properties of the TM and TA and experiments performed on near‐field imaging with the TA. The second technique is based on solid immersion microscopy, in which high resolution is achieved when light is focused inside a solid with a high refractive index. By creating a transient Fresnel lens on the surface of a semiconductor wafer via photoinduction, we were able to form a solid immersion lens (SIL) for use as a near‐field probe. The use of transient probes eliminates the need for mechanical scanning of the lens or sample, and thus provides a much faster scanning rate and the possibility to work with soft and liquid objects.     

基于太赫兹衰减全反射光谱法的无创血糖检测研究

结合太赫兹时域光谱系统,利用棱镜衰减全反射技术,设计了一种太赫兹衰减全反射光谱法的无创血糖检测系统。借助德拜模型分析了皮肤中含水量变化会影响皮肤在太赫兹波段的弛豫作用,得到皮肤复折射率与皮肤含水量的关系,利用菲涅耳公式给出了计算皮肤复折射率实部和虚部的方法。将太赫兹光谱法测得的人体大拇指皮肤复折射率的实部与虚部,与口服葡萄糖耐量试验实际测得的人体血糖浓度进行对比,得到了人体手指皮肤的太赫兹反射谱以及复折射率与人体血糖浓度成正相关的关系,为太赫兹应用于无创血糖浓度检测提供了参考。     

可激发等离子体表面波的离子交换单模条波导

设计并制备了离子交换单模条波导,用于激发等离子体表面波.研究了波导设计过程中相关参数的确定方法、条波导制备过程涉及的二维扩散问题,折射率分布以及等离子体表面波的激发等.基于Ag+-Na+离子交换技术在德国B270光学玻璃上制备出渐变型平面波导,采用余误差函数拟合其折射率分布,得到了一定工艺参数下的光波导扩散系数Deff...     

Detection of erythrocytes in patients with multiple myeloma using atomic force microscopy

The goal of this study was to examine the pathophysiological changes to erythrocytes in multiple myeloma (MM) patients at a nanometer scale. We hypothesize that studying changes in red blood cells may be important for early diagnosis and effective treatment of MM. Blood samples were taken from ten healthy volunteers and ten MM patients before and after treatment. Changes in the morphological and biomechanical properties of the erythrocytes were studied at a nanometer scale with atomic force microscopy (AFM). There were dramatic deformations in the overall shape and surface membrane of the erythrocytes from pre‐ and post therapeutic MM patients compared with the healthy controls. Healthy and pathological MM erythrocytes could be distinguished by several morphologic parameters, including the width, length, length to width ratio, valley, peak, valley‐to‐peak, standard deviation, and surface fluctuation. The effectiveness of disease treatment could also be evaluated by studying these red blood cell parameters. AFM was able to detect noticeable morphological differences in the red blood cells from MM patients compared with healthy controls. Therefore, erythrocyte morphology is an important parameter for diagnosing MM, as well as evaluating the efficacy of disease treatment. SCANNING 34: 295–301, 2012. © 2012 Wiley Periodicals, Inc.     

球形金纳米颗粒的消光特性及不同折射率环境下的共振波长

为了研究球形Au纳米颗粒的消光特性及共振波长与环境折射率的关系,采用Mie理论计算了直径为20,40,60和80nm的球形Au纳米颗粒在不同折射率的介质环境中的消光谱,并利用消光法实验测量了这4种粒径的Au纳米颗粒在不同浓度糖水中的吸光度,取得了糖水介质环境的折射率与浓度之间的关系及其色散规律,以及Au纳米颗粒的消光系数及共振波长随环境折射率变化的数据。结果表明,介质环境糖水浓度一定时,Au颗粒半径增大,消光峰值红移;颗粒半径一定时,周围介质环境糖水浓度增大,消光峰值红移;Au纳米颗粒的共振波长与糖水浓度呈线性关系,20,40,60,80nm的Au纳米颗粒对应的线性斜率分别为0.106 0,0.135 5,0.193 8,0.265 8,斜率随粒径尺寸的增大而增大。该结论为探索纳米颗粒的折射率敏感性奠定了基础。     

Fluorescence microscopy of rat embryo sections stained with haematoxylin–eosin and Masson's trichrome method

The fluorescence pattern induced by haematoxylin–eosin (HE) and Masson's trichrome (MT) staining methods on paraffin sections of rat embryos (from 13 to 18 days old) has been studied. Using optimal excitation (green light, 545 nm), HE- or MT-stained sections showed a selective red emission of the acidophilic tissue components, which was due to eosin Y in the case of HE and to acid fuchsin and/or xylidine ponceau in the case of MT. The fluorescence intensity induced by these anionic dyes was variable and related to the substrate nature and the embryo age. Whereas in young embryos only the immature red blood cells showed a noticeable fluorescence, in the oldest embryos there were also other tissue components that selectively fluoresced with these dyes, in particular fibre lens cells, elastic fibres, zymogen granules and muscle cells. Spectrofluorometric studies on free dyes and densitometric analysis of protein blots confirmed microscopical observations. Our results indicate that the standard HE and MT staining methods can be used in recognizing the appearance of specific protein structures in embryonic tissues by means of fluorescence microscopy.     

用预抽气真空腔法测量及补偿空气折射率的研究

空气折射率的补偿效果在高精度激光干涉测量中起着“瓶颈”作用。分析了空气折射率的补偿原理,回顾了几种空气折射率的测量方法及特点。在此基础上,深入研究了用预抽气真空腔测量与补偿空气折射率的测量原理、方法和装置。该方法保持了干涉法测量空气折射率能充分反映所有导致折射率变化的环境因素的特点,避免了测量过程中由于抽气过程给测量带来的干扰。通过空气折射率测量及补偿实验,证实了该方法的可行性,测量结果经补偿后可使精度提高一个数量级。     

On a novel approach to evaluate Schlieren interferograms of axisymmetric refractive index fields

In Schlieren interferometry one often encounters axisymmetric refractive index fields which principally violate the general assumption of interferometry, namely the two-dimensionality of the phase object. However, there exist numerical methods capable to evaluate axisymmetric refractive index fields using the fringe distribution of interferograms. This paper describes a novel approach for evaluating Schlieren interferograms of axisymmetric refractive index fields. The suggested algorithm exhibits higher accuracy without constrains for large beam separation (where the interferometer sensitivity is higher) when compared to methods given in the literature. The computational performance has been controlled and compared by using analytical test functions.     

A setup for measuring the refractive index of a plane-parallel ceramic plate using the optical beam shift method

A setup for measuring the refractive indices of transparent solid samples of optical ceramics using shifts of a beam by a plane-parallel plate in a wavelength range of 400–1200 nm was developed. The minimum cross-sectional sizes of the investigated objects are 5–12 mm, and their thicknesses are 0.3–1.0 mm. A standard sample and a precise system for forming and recording optical signals equipped with a stepping motor with a step discreteness of <1 μm were used to improve the measurement accuracy of the refractive index. The cross-sectional size of the measuring beam is ?1 mm. The accuracy in determining the refractive index is ±0.004.     

离子交换单模条波导的折射率分布控制与制备

为了控制离子交换条波导的折射率分布,提出并实施了离子交换等效扩散系数和表面折射率增量的实验确定方法,导出了离子交换条波导制备过程涉及的两维扩散方程的一般解,拟合推定了离子交换条波导的折射率分布。利用等效折射率法给出了单模波导条件,设计了相应的工艺参数,在0.1%AgNO_3—99.9%NaNO_3混合熔融盐中实验制备了单模条波导,模场分布测试结果显示了良好的单模特性。     

Interferometric determination of the optical properties of fibres with irregular transverse sections (Ramie)

The thickness of fibres and their irregularity were determined from the forward scattering of a He-Ne laser beam. Two methods have been used for the measurement of refractive indices and birefringence of Ramie fibres. The first of these methods is the application of multiple-beam Fizeau fringes in transmission and at reflection. The second is the use of the double refracting interference microscope designed and developed by Pluta. In each method, refractive index values have been determined using two different analyses of the interference pattern. To overcome the difficulty of the irregular transverse section of Ramie fibres, the area enclosed under the fringe shift is considered as representing the path difference integrated across the fibre.     

液体折射率测定方法分析

折射率是反映介质光学性质的一个重要参数,对其精确测定有重要的意义。文章对液体折射率测量方法做了归纳和分类,并对几种主要测定方法做了介绍,分析了各自的特点和存在的问题。尤其对基于表面等离子体波共振效应的新型光纤传感系统的结构、工作原理及其在液体折射率测定等方面应用做了具体的分析和介绍。