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101.
The temperature distribution over the end of a gallium arsenide diode, which is operating in the laser and spontaneous mode, is measured by a radiation pyrometer method. The effect of radiative and nonradiative recombination of the minority carriers and the ohmic heating in raising the temperature of the radiator is estimated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 134–138, June, 1978. 相似文献
102.
An original, quantitative, theory of “living” radical copolymerization has been developed proceeding from the current concepts
of its kinetics and mechanism. This theory enables one to calculate both the dependence of monomers' conversion on time and
any statistical characteristics of the chemical structures of the copolymers formed. Expressions have been derived describing
the angular dependence of the scattering amplitude of the copolymerization products. The results of quantitative calculations
of these characteristics have been also presented to exemplify the potentialities of the theory.
Received 13 February 2001 and Received in final form 4 February 2002 相似文献
103.
Alicia Dickenstein Laura Felicia Matusevich Timur Sadykov 《Advances in Mathematics》2005,196(1):78-123
We undertake the study of bivariate Horn systems for generic parameters. We prove that these hypergeometric systems are holonomic, and we provide an explicit formula for their holonomic rank as well as bases of their spaces of complex holomorphic solutions. We also obtain analogous results for the generalized hypergeometric systems arising from lattices of any rank. 相似文献
104.
Chitosan membrane with glutathione reductase and sulfhydryl oxidase (SOX) was subsequently integrated onto the surface of spectrographic graphite rods for obtaining a glutathione biosensor. The working principle was based on the monitoring of O2 consumption that correlates the concentration of glutathione during the enzymatic reaction. A linear relationship between sensor response and concentration was obtained between 0.5 and 2.0 mM for oxidized glutathione (GSSG), and 0.2–1.0 mM for reduced glutathione (GSH) in the presence of 2 μM nicotinamide adenine dinucleotide phosphate (NADPH) under the optimum working conditions. Also, reduced/oxidized glutathione were separated by HPLC and utility of bienzymatic system was investigated as an electrochemical detector for the analysis of these compounds. All data were given as a comparison of two systems: biosensor and diode array detector (DAD). 相似文献
105.
Ye T Kaur R Senguen FT Michel LV Bren KL Elliott SJ 《Journal of the American Chemical Society》2008,130(21):6682-6683
Protein film voltammetry (PFV) is used to interrogate the behavior of a variety of bacterial and mitochondrial His/Met-ligated cytochromes c. While analogous studies upon alkanethiol-modified gold electrodes reveal the anticipated Fe(II/III) couple only, PFV using pyrolytic graphite edge (PGE) electrodes demonstrates the presence of a lower-potential form of each of the cyts c studied, with a potential of approximately -100 mV (vs hydrogen). The generation of the novel, lower-potential state is shown to arise specifically from the interaction with the PGE electrode. Simultaneously, the typical Fe(II/III) couple can be observed. PFV of a series of wild-type cytochromes and mutants in the Met-donating loop show that the lower-potential state is highly similar between proteins from Pseudomonas aeruginosa (PA), Hydrogenobacter thermophilus (HT), and horse heart. The generation of the lower-potential form correlates inversely with the stability of the Met-Fe interaction for each of the cytochromes. Comparison with chemically unfolded cyts c indicates that the lower-potential forms detected here are unique, and this distinct state is ascribed to the loss of the Met ligand. Thus, PGE is demonstrated to be a non-innocent electrode surface in PFV studies of His/Met-ligated cytochromes c. 相似文献
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109.
Igor Rodin Arcady Braun Andrey Stavrianidi Timur Baygildiev Igor Rybalchenko Oleg Shpigun 《International journal of environmental analytical chemistry》2016,96(5):436-444
A novel sensitive screening method based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) has shown the feasibility of separation and detection of thiodiglycolic acid in aqueous samples. The analysis of this compound is of interest since it is specific microbiological metabolite of thiodiglycol, which is precursor and degradation product of chemical warfare agent sulfur mustard. The LC–electrospray ionisation (ESI)–MS method provides a sensitive and direct approach for thiodiglycolic acid identification and quantification using non-extracted non-derivitised samples from aqueous solutions. Chromatographic separation of the thiodiglycolic acid was produced using a reverse phase LC column with gradient mobile phases consisting of 0.1% formic acid in water and acetonitrile. Identification and quantification of species were achieved using ESI–tandem MS monitoring two precursor-to-product ion transitions for thiodiglycolic acid. The method demonstrates linearity over at least two orders of magnitude and detection limit of 10 ng...mL–1 in environmental water samples. 相似文献
110.
Hacer Azak Firat Baris Barlas Huseyin Bekir Yildiz Kadri Gulec Bilal Demir Dilek Odaci Demirkol Suna Timur 《Macromolecular bioscience》2016,16(4):545-552
Here, postfunctionalization and bioapplication of a π‐conjugated polymer named 4‐[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl]aniline (DTP‐aryl‐NH2) are reported, which is successfully synthesized via electropolymerization onto the glassy carbon electrode. Folic acid (FA) is used to modify the amino functional polymer via N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride/N‐hydroxysuccinimide chemistry for the further steps. The selective adhesion of folate receptor positive cells on the surface is followed by the electrochemical methods. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize stepwise modification of the electroactive surface. After optimization studies such as scan rate during the polymer deposition, FA amount for the efficient surface targeting, incubation time with the cells etc., analytical characterization is carried out. The surface morphologies at each step are imaged by using fluorescence microscopy.