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31.
Hans Kreis und Emil Roth 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1913,26(1):38-42
Ohne ZusammenfassungMitteilung aus dem Laboratorium des Kantons-Chemikers Basel-Stadt. 相似文献
32.
Violeta Melinte Tinca Buruiana Daniel Tampu Emil C Buruiana 《Polymer International》2011,60(1):102-111
The modern synthesis of novel functional materials with improved properties includes that of hybrid nanocomposites composed of inorganic nanoparticles and organic derivatives, where controlling the molecular structure at atomic and macroscopic dimensions is a key factor, with a major effect on performance. An extension of this approach to the field of nanocomposites containing photopolymers with triazene groups attached on a methacrylic backbone could be of great interest in the future development of chemosensors and photoresists, among others. Photopolymer/clay nanocomposites were prepared by in situ free radical copolymerization of 1‐(phenyl)‐3‐(2‐methacryloyloxyethylcarbamoyloxyethyl)‐3‐methyltriazene‐1 or 1‐(p‐methoxyphenyl)‐3‐(2‐methacryloyloxyethylcarbamoyloxyethyl)‐3‐methyltriazene‐1 and vinyl acetate or styrene in solution and in the presence of 3 and 5 wt% of organically modified montmorillonite. The characterization of the nanocomposites and pure copolymers was achieved through 1H NMR and Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, X‐ray diffraction, atomic force microscopy and fluorescence analysis. The morphologies and properties of the nanocomposites are dependent on the nature of the triazene, on the co‐monomer structure and on the organoclay content. Also, the fluorescence response of these nanocomposites towards certain metal ions (Fe3+, Cu2+, Hg2+, Ni2+) in dimethylformamide solution was investigated. The effect of uranyl ions on the fluorescence intensity of the nanocomposites in solution or as films could be exploited in the development of ‘turn‐off’ or ‘turn‐on’ chemosensors for this type of analyte. Triazeno copolymer/organophilic montmorillonite nanocomposites with exfoliated (not completely exfoliated) or exfoliated and intercalated structures exhibit distinct characteristics concerning their fluorescence behaviour, a higher sensing ability towards certain target compounds (Fe3+, UO22+) being evidenced for those incorporating 3 wt% organoclay in solution and as films. Copyright © 2010 Society of Chemical Industry 相似文献
33.
Badr Bassou Nolven Guilhaume Eduard Emil Iojoiu David Farrusseng Karine Lombaert Daniel Bianchi Claude Mirodatos 《Catalysis Today》2011,159(1):103-143
Following the development of a high-throughput (HT) methodology for the evaluation of diesel soot oxidation catalysts in a 16 parallel channels reactor, a library of over 60 catalysts was tested under optimized conditions. The catalyst compositions were chosen to include solids which specific properties like oxygen storage capacity, oxygen mobility and ionic conductivity. The key parameters for high activity appear related to the presence of active and mobile surface oxygen species, and to an appropriate catalyst particle size in order to favour the number of contacts with the soot. In contrast, high oxygen storage capacity and bulk oxygen ion mobility do not appear as relevant properties for high catalytic activity. Nine new formulations were found to perform better than the reference catalyst “high surface area (HSA) ceria” (Rhodia). 相似文献
34.
In this paper, a gap discharge approach to create acoustic signals for ultrasonic low pressure gas flow measurements is investigated. The objective is to develop an ultrasonic gas flow meter system that is capable of operation in extreme industrial environments. These environments might have extremely high temperatures (1200 °C), moisture, steam, dust, low gas pressure and large transmission distances.Most other types of ultrasonic transducers found show sensitivity to such conditions: their operation suffers, or they may even stop functioning if exposed to such environments. The development of new transducer technology is therefore crucial to allow ultrasonic flow measurements in extreme industrial environments. In this paper, the gap discharge emitter is evaluated as a candidate to be used in these applications. Its capabilities as a sound source are investigated, and its impact on flow meter performance is estimated. It can be concluded that, despite the uncertainties it introduces to a flow meter system, it stands out as a strong candidate to be used as an acoustic emitter in a gas flow meter system for extreme environments. 相似文献
35.
Highly sensitive label-free techniques of DNA determination are particularly interesting in relation to the present development of the DNA sensors. We show that subnanomolar concentrations (related to monomer content) of unlabeled DNA can be determined using copper solid amalgam electrodes or hanging mercury drop electrodes in the presence of copper. DNA is first treated with acid (e.g., 0.5 M perchloric acid), and the acid-released purine bases are directly determined by the cathodic stripping voltammetry. Volumes of 5-3 microL of acid-treated DNA can easily be analyzed, thus making possible the determination of picogram and subpicogram amounts of DNA corresponding to attomole and subattomole quantities of 1000-base pair DNA. Application of this determination in DNA hybridization detection is demonstrated using surface H for the hybridization (superparamagnetic beads with covalently attached DNA probe) and the mercury electrodes only for the determination of DNA selectively captured at surface H. 相似文献
36.
37.
Emil Simiu 《Engineering Structures》1983,5(4):273-281
This is the fourth in a series of review papers devoted to the state-of-the-art in wind engineering. The first three parts of the series were published in the October 1981 (pp. 233–241 and 242–248) and March 1982 (pp. 66–74) issues of Engineering Structures. 相似文献
38.
A survey questionnaire eliciting information on the number of internships offered, average salary of interns, selection criteria, and percentages of work time was sent to 294 American Psychological Association (APA)- and non-APA-approved internship sites. Results of this study and the new criteria for accreditation indicate that students from approved doctoral programs have a definite advantage in the internship marketplace. Sufficient evidence exists, however, to conclude that students from non-APA-approved programs may be encouraged to risk competing for APA-approved internships. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
39.
Mathematical statistics are used to design electronic systems in which the effects of the initial variations of the system parameters and the drift of these parameters on the system performance criteria are a minimum. This is accomplished by minimizing the initial variances of the system performance criteria with respect to the initial mean values of the system parameters while constraining the means of these parameters to their required values. In addition, the drift rates of the system parameters are selected in such a manner as to prevent the drift of the mean values of the system performance criteria while reducing the tendencies of the variances of these criteria to increase with time. These techniques were successfully applied to a number of electronic systems, including systems with both active and passive elements, thus illustrating the usefulness of mathematical statistics in the design of mass produced electronic systems. 相似文献
40.
Korotkova O Wolf E 《Journal of the Optical Society of America. A, Optics, image science, and vision》2004,21(12):2382-2385
The complex spectral degree of coherence of a general random, statistically stationary electromagnetic field is introduced in a manner similar to the way it is defined for a beamlike field, namely, by means of Young's interference experiment. Both its modulus and its phase are measurable. We illustrate the definition by applying it to blackbody radiation emerging from a cavity. The results are of particular interest for near-field optics. 相似文献