共查询到20条相似文献,搜索用时 46 毫秒
1.
A method of making the multiple regional renograms and simple functional images are described. Thirty-six EDTA (or DTPA) images has been transferred from a gamma camera to a small computer with the magnetic tape. Thirteen regional renograms from a kidney have been made by using the single pixel ROIs from these images, a continuous 13 pixels horizontal and/or vertical of the matrix are selected, in distinction from right and left kidney. Two functional images have been made by the multi-frame images as a peak arrival time and it's peak counts. Small change of the radioisotopic transportation in the kidney could be observed by the method, and change of the urodynamics could be extracted by two functional images. It will be actualize quantitative diagnosis to the renal function disorders. 相似文献
2.
Visualisation of an ultrafiltration membrane by non-contact atomic force microscopy at single pore resolution 总被引:1,自引:0,他引:1
W. Richard Bowen Nidal Hilal Robert W. Lovitt Peter M. Williams 《Journal of membrane science》1996,110(2):229-232
Non-contact atomic force microscopy (AFM) has been used to investigate the furface pore structure of a polyethersulfone ultrafitration membrane of specified molecular weight cut off (MWCO) 25 000 (ES625, PCI Membrane Systems). Excellent images at up to single pore resolution were obtained. This is the first time that AFM images of a membrane at such high resolution have been presented. Analysis of the images gave a mean pore size of 5.1 nm with a standard deviation of 1.1 nm. The results have been compared to previously published studies of membranes of comparable MWCO using contact AFM and electron microscopy. Non-contact AFM is a powerful means of studying the surface pore characteristics of ultrafiltration membranes. 相似文献
3.
The crystallization of the isotactic poly(propylene) (I-PP) has been studied carrying out measurements by means of a special calorimeter connected to a microscope and a digital acquisition system of images. To authors' knowledge, this is the first time that simultaneous calorimetric and optical measurements are carried out on polymers. The analysis of Polarized Optical Microscopy images has allowed the appraisal of nucleation density and growth rate in isothermal and non isothermal conditions. The results obtained in isothermal conditions have been analyzed through the Kolmogoroff model and the crystallinity calculated from the model has been compared with that obtained from the calorimetric measurements. 相似文献
4.
G. M. Fuchs T. Prohaska G. Friedbacher H. Hutter M. Grasserbauer 《Fresenius' Journal of Analytical Chemistry》1995,351(2-3):143-147
The Maximum Entropy Method (MEM) has been applied successfully to the deconvolution of images obtained by Atomic Force (AFM) and Scanning Tunneling Microscopy (STM) using a NanoScope III system. The images have been taken on graphite (STM) and NaCl (AFM) substrates. Image processing has been performed running the Cambridge MaxEnt Fortran 77 library MEMSYS-5 on an IBM RISC 6000/360. Among the possible hypotheses the optimal solution was selected using the standard entropy method. ICF and response function have been generated artificially to fit the correlation of physical structures for atomically resolved images. Comparison of MEM and FFT revealed, that the main advantage of MEM is its ability to reproduce atomic defects on regular structures, whereas FFT deconvolution tends to eliminate these perturbations. 相似文献
5.
Wienke D Van Den Broek W Melssen W Buydens L Feldhoff R Huth-Fehre T Kantimm T Winter F Cammann K 《Analytical and bioanalytical chemistry》1996,354(7-8):823-828
An infrared camera with focal plane InSb array detector has been applied to the characterization of macroscopic samples of household waste over distances up to two meters. Per waste sample (singelized), a sequence of images was taken at six optical wavelength ranges in the near infrared region (1100 nm - 2500 nm). The obtained three-dimensional data stack served as individual fingerprint per sample. An abstract factor rotation of this stack of six images into a spectroscopical meaningful intermediate six-element vector by Multivariate Image Rank Analysis (MIRA) finally provided a decision limit for the discrimination of plastics and nonplastics. A correct classification of better than 80% has been reached. The experimental NIRIS set-up has been automated so far to allow an on-line identification of a real world waste sample within a few seconds. 相似文献
6.
D. Wienke W. van den Broek W. Melssen L. Buydens R. Feldhoff T. Huth-Fehre T. Kantimm F. Winter K. Cammann 《Fresenius' Journal of Analytical Chemistry》1996,354(7-8):823-828
An infrared camera with focal plane InSb array detector has been applied to the characterization of macroscopic samples of household waste over distances up to two meters. Per waste sample (singelized), a sequence of images was taken at six optical wavelength ranges in the near infrared region (1100 nm – 2500 nm). The obtained three-dimensional data stack served as individual fingerprint per sample. An abstract factor rotation of this stack of six images into a spectroscopical meaningful intermediate six-element vector by Multivariate Image Rank Analysis (MIRA) finally provided a decision limit for the discrimination of plastics and nonplastics. A correct classification of better than 80% has been reached. The experimental NIRIS set-up has been automated so far to allow an on-line identification of a real world waste sample within a few seconds. 相似文献
7.
Fluorescence Lifetime Imaging of Experimental Tumors in Hematoporphyrin Derivative-Sensitized Mice 总被引:1,自引:0,他引:1
Rinaldo Cubeddu Gianfranco Canti Antonio Pifferi Paola Taroni Gianluca Valentini 《Photochemistry and photobiology》1997,66(2):229-236
Tumor detection has been carried out in mice sensitized with hematoporphyrin derivative (HpD) by measuring the spatial distribution of the fluorescence lifetime of the exogenous compound. This result has been achieved using a time-gated video camera and a suitable mathematical processing that led to the so-called “lifetime images.” Extensive experimental tests have been performed on mice bearing the MS-2 fibrosarcoma or the L1210 leukemia. Lifetime images of mice show that the fluorescence decay of HpD is appreciably slower in the tumor than in healthy tissues nearby, allowing a reliable detection of the neoplasia. The lengthening of the lifetime in tumors depends little on the drug dose, which in our experiments could be lowered down to 0.1 mg/kg body weight, still allowing a definite tumor detection. In order to ascertain the results achieved with the imaging apparatus, high-resolution spectroscopy, based on a time-correlated single photon counting system, has also been performed to measure the fluorescence lifetime of the drug inside the tumor and outside. The outcomes obtained with two techniques are in good agreement. 相似文献
8.
Scanning tunneling microscopy (STM) has been a fundamental tool to characterize many-body effects in condensed matter systems, from extended solids to quantum dots. STM of molecules decoupled from the supporting conductive substrate has the potential to extend STM characterization of many-body effects to the molecular world as well. In this paper, we describe a many-body tunneling theory for molecules decoupled from the STM substrate, and we report on the use of standard quantum chemical methods to calculate the quantities necessary to provide the "correlated" STM molecular image. The developed approach has been applied to 18 different molecules to explore the effects of their chemical nature and of their substituents, as well as to verify the possible contribution by transition metal centers. Whereas the bulk of calculations has been performed with the configuration interaction method with single and double excitations (CISD), because of the computational cost some tests have been also performed with the more accurate coupled cluster with single and double excitations (CCSD) method to quantify the importance of the computational level on many-body STM images. We have found that correlation induces a remarkable squeezing of the images, and that correlated images are not derived from Hartree-Fock HOMO or LUMO alone, but include contributions from other orbitals as well. Although correlation effects are too small to be resolved by present STM experiments for the studied molecules, our results provide hints for seeking out other species with larger, and possibly experimentally detectable, correlation effects. 相似文献
9.
The agricultural industry is among the most important industry in the world and playing a critical part in human growth. Soil classification is becoming incredibly valuable, and recent study reveals that classification of images is proven as the preferred way of soil information for farmers. The testing of soil is the first step in construction planning to determine whether the plot of land is suitable for constructing any structure in order to prevent future disasters. In this work, the model has been proposed to address the visual classification of types of soil using the deep neural network (DNN) and tensor flow framework. Further, AI based sequential model has been created in python to classify the soil. This has been analyzed that with the use of proposed technique five types of soil viz. black, cinder, laterite, peat, and yellow soil has been classified while keeping the practical simplicity of the images. Far superior accuracy has been achieved using the CNN model on the above dataset. The model is useful for farmers to increase the crop production after identification of the appropriate soil type for respective crops. 相似文献
10.
A C Diebold B Foran C Kisielowski D A Muller S J Pennycook E Principe S Stemmer 《Microscopy and microanalysis》2003,9(6):493-508
High-resolution transmission electron microscopy (HR-TEM) has been used as the ultimate method of thickness measurement for thin films. The appearance of phase contrast interference patterns in HR-TEM images has long been confused as the appearance of a crystal lattice by nonspecialists. Relatively easy to interpret crystal lattice images are now directly observed with the introduction of annular dark-field detectors for scanning TEM (STEM). With the recent development of reliable lattice image processing software that creates crystal structure images from phase contrast data, HR-TEM can also provide crystal lattice images. The resolution of both methods has been steadily improved reaching now into the sub-Angstrom region. Improvements in electron lens and image analysis software are increasing the spatial resolution of both methods. Optimum resolution for STEM requires that the probe beam be highly localized. In STEM, beam localization is enhanced by selection of the correct aperture. When STEM measurement is done using a highly localized probe beam, HR-TEM and STEM measurement of the thickness of silicon oxynitride films agree within experimental error. In this article, the optimum conditions for HR-TEM and STEM measurement are discussed along with a method for repeatable film thickness determination. The impact of sample thickness is also discussed. The key result in this article is the proposal of a reproducible method for film thickness determination. 相似文献
11.
《Journal of solid state chemistry》1986,61(2):212-222
High resolution electron microscopy (HREM) of Fe3O4 has been carried out at temperatures near the Verwey transition (∼120 K) with a point resolution of 3 Å. Lattice fringes of both the high- and the low-temperature phases have been observed at these temperatures. The crystal symmetry of the low-temperature phase indicated by the lattice images is consistent with the result obtained by earlier diffraction studies. A series of lattice images showing the transition from the low-temperature phase (to the high-temperature phase) has been obtained. The transformation to the high-temperature phase occurs through the penetration of the high-temperature phase into areas of the low-temperature phase. A quick motion of domain boundaries in the low-temperature phase, which is consistent with almost instantaneous rearrangements of charge ordering, has been observed. The possibility of determining the ordered arrangement of Fe2+ and Fe3+ ions directly by HREM is discussed. 相似文献
12.
An optical sensor array based on chemiluminescent images from spots of nanomaterials has been employed to recognize odorous samples. The distinctive images obtained from the array permit identification of a wide range of analytes, even homologous compounds. 相似文献
13.
Yu. M. Yukhin A. I. Titkov O. A. Logutenko K. V. Mishchenko N. Z. Lyakhov 《Russian Journal of General Chemistry》2017,87(12):2870-2874
The extraction of copper, silver, bismuth, and nickel with carboxylic acids thus providing concentrated metal-containing organic solutions and their crystalline salts has been studied. Micron- and submicron-sized metal powders have been obtained via reduction of these metals carboxylates by heating in benzyl alcohol or ethylene glycol. The synthesis of aspherical silver nanoparticles has been achieved by the reduction of a liquid extract of silver neodecanoate in benzyl alcohol. The possibility of the use of concentrated silver-containing solutions as inks for obtaining of electroconductive images has been demonstrated. 相似文献
14.
Xu QM Wang D Han MJ Wan LJ Bai CL 《Langmuir : the ACS journal of surfaces and colloids》2004,20(8):3006-3010
Scanning tunneling microscopy (STM) combined with cyclic voltammetry has been employed to investigate the adsorption of cinchonine on Cu(111). Similar to cinchonidine, cinchonine forms a long-range ordered adlayer with (4 x 4) symmetry on the substrate. The structural details on molecular adsorption were obtained by high-resolution STM images. On the basis of the previous results and obtained STM images, the quinoline ring is proposed to lie parallel to Cu(111) and serve as an anchoring group. The chiral quinuclidine moiety extends out of the surface to facilitate the interaction with the prochiral reactants. 相似文献
15.
The flexibility of most mesogenic molecules creates a problem when we wish to consider their shape, especially as the anisotropy in this is often invoked to explain liquid-crystalline behaviour. It has been suggested that images constructed from the average positions of atoms in the molecule with superimposed ellipsoids representing the mean square displacements of the atoms could present one solution to the problem. However, the nature of the image necessarily depends on the choice of the reference frame set in the molecule. Here we show how the images change as the atoms used to define the reference frame move along a single heptyl chain attached to a mesogenic core in both the isotropic and nematic phases. The appearance of the images and how they change with phase and reference frame are discussed in general terms. In addition, the possible relationship between the images and the order parameters for axes set in the same reference frame as that used to construct the image is explored. The significance of the fluctuational ellipsoids is also considered although they appear only to influence the order parameters at second order. 相似文献
16.
V. P. Kolotov D. S. Grozdov N. N. Dogadkin 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(2):347-352
It has been demonstrated that pixel-by pixel processing of series of autoradiography images for revealing the dynamics of
decay of the induced radionuclides is an efficient approach for mapping of radionuclides in the sample in activation autoradiography.
Concepts of virtual scanner and corresponding software for linearization of dependence of optical density on scanner response
(luminosity) have been introduced. The concept provides unification of the subsequent processing of autoradiograms, irrespective
of the method as to how the digital image has been obtained. Algorithms and the software for estimation of decay parameters
of a radionuclide mixture for each pixel using a series of coaxially positioned images have been developed. The software is
able generate a set of the derivative meta-images allowing a conclusion to be made about the presence of the inclusions in
question. To increase the reliability of radionuclide mapping it is suggested to use analysis of distribution of half-life
values estimated for pixels of image zone(s) pointed by a special mask. 相似文献
17.
《Vibrational Spectroscopy》2002,28(1):37-43
A digital imaging system has been developed to collect skin hydration data. The system combines a near-infrared camera with a liquid-crystal tunable filter (LCTF) to acquire spectral images at multiple narrow wavelength bands between 960 and 1700 nm. Software has been developed to control the instrument and to process the data. Reflectance images were collected of subjects whose forearms had been treated to increase and decrease skin moisture. The infrared absorption band between 1400 and 1500 nm was used to calculate relative skin moisture, and the intensity of this band was plotted as a function of position in the form of a grayscale image. This is a rapid, non-contact and non-invasive technique to provide information on skin hydration of use to medical and cosmetic research and clinical practice. 相似文献
18.
Ana M Sanchez Pedro L Galindo Slawomir Kret Meiken Falke Richard Beanland Peter J Goodhew 《Microscopy and microanalysis》2006,12(4):285-294
A systematic distortion in high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) images, which may be caused by residual electrical interference, has been evaluated. Strain mapping, using the geometric phase methodology, has been applied to images acquired in an aberration-corrected STEM. This allows this distortion to be removed and so quantitative analysis of HAADF-STEM images was enabled. The distortion is quantified by applying this technique to structurally perfect and strain-free material. As an example, the correction is used to analyse an InAs/GaAs dot-in-quantum well heterostructure grown by molecular beam epitaxy. The result is a quantitative measure of internal strain on an atomic scale. The measured internal strain field of the heterostructure can be interpreted as being due to variations of indium concentration in the quantum dot. 相似文献
19.
Design of Aromatic Helical Polymers for STM Visualization: Imaging of Single and Double Helices with a Pattern of π–π Stacking
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Dr. Junyan Zhu Prof. Zeyuan Dong Prof. Shengbin Lei Dr. Lili Cao Prof. Bing Yang Dr. Wenfang Li Yuanchao Zhang Prof. Junqiu Liu Prof. Jiacong Shen 《Angewandte Chemie (International ed. in English)》2015,54(10):3097-3101
From scanning tunneling microscopy (STM) images of rationally designed helical polymers with a pattern of π–π stacking, we successfully identified the single‐ and double‐helical superstructures. The STM images of the helical structures revealed the smallest helical architecture (diameter ca. 1.3 nm) that has been seen so far. Furthermore, the interconversion of single and double helices was further underpinned by experimental analyses. Significantly, the formation of double helices induced different supramolecular chirality to that observed for the single helices. 相似文献
20.
Scanning electron microscopy (SEM) is a powerful imaging technique able to obtain astonishing images of the micro- and the nano-world. Unfortunately, the technique has been limited to vacuum conditions for many years. In the last decades, the ability to introduce water vapor into the SEM chamber and still collect the electrons by the detector, combined with the temperature control of the sample, has enabled the study of ice at nanoscale. Astounding images of hexagonal ice crystals suddenly became real. Since these first images were produced, several studies have been focusing their interest on using SEM to study ice nucleation, morphology, thaw, etc. In this paper, we want to review the different investigations devoted to this goal that have been conducted in recent years in the literature and the kind of information, beyond images, that was obtained. We focus our attention on studies trying to clarify the mechanisms of ice nucleation and those devoted to the study of ice dynamics. We also discuss these findings to elucidate the present and future of SEM applied to this field. 相似文献