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1.
A possible method for the simulation of nonideal op-amps with a finite gain and bandwidth by means of an equivalent SC circuit, containing ideal components, is presented. The approach is extended by the case of an op-amp with non-switched input SC building blocks. 相似文献
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E. I. Leyarovski J. K. Georgiev A. L. Zahariev 《International Journal of Thermophysics》1988,9(3):391-408
A new method for experimental determination of the thermal diffusion factor
T for binary gas mixtures with a thermal diffusion column (TDC) is developed, based on A. M. Rozen's equation of TDC. The experimental results for
T are obtained in a reduced form in this approximation. An experimental reference point, determined in the same TDC with a standard gas mixture, is used for the transformation of the results for
T in absolute units. The proposed method is applicable for arbitrary gas mixtures, irrespective of the mass difference of the components. 相似文献
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In a pilot plant biconstitusent fibres with poly(ethylene terephthalate) as main component and poly(caproamid) as second component were produced. Their microstructure, their behaviour during melting and crystallization, some dynamic-mechanic and mechano-textile properties as well as some electrostatic, hygroscopic and dyeing properties were determined. The biconstituent fibres have a low capability for electrifying and tend to show a “pilling”-effect. Their dyeing abilities open possibilities for interesting dyeing effects. An aim of the investigation was to clear some changes in the physical and mechanical properties of the biconstituent fibres from the view of their fibrille-matrix-structure and from the mutual effect between the two components at the interphase. 相似文献
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Häfliger P Agorastos N Spingler B Georgiev O Viola G Alberto R 《Chembiochem : a European journal of chemical biology》2005,6(2):414-421
The potential of certain Auger electron emitting nuclides for systemic radiotherapeutic applications has recently gained much attention. In particular, the ability of several nuclides, including 111In, 125I, and 123I, to induce DNA double-strand breaks (dsb), a good indicator of cytotoxicity, has been extensively studied. However, this ability has never previously been shown experimentally for 99mTc, which, besides the well-known gamma radiation that is used for diagnostic applications, also emits an average of 1.1 conversion electrons and 4 Auger or Coster-Kronig electrons per decay. Owing to the short range of Auger electrons, the radionuclide needs to be located very close to the DNA for dsb to occur. We synthesized two cationic 99mTcI-tricarbonyl complexes with pendant DNA binders, pyrene and anthraquinone. The X-ray crystal structures of the two complexes could be elucidated. Linear dichroism and UV/Vis spectroscopy revealed that the complex with pyrene intercalates DNA with a stability constant, K, of 1.1 x 10(6) M(-1), while the analogous complex with anthraquinone interacts with DNA in a groove-binding mode and has an affinity value of K=8.9 x 10(4) M(-1). We showed with phiX174 double-stranded DNA that the corresponding 99mTc complexes induce a significant amount of dsb, whereas non-DNA-binding [TcO4]- and nonradioactive Re compounds did not. These results indicate that the Auger electron emitter 99mTc can induce dsb in DNA when decaying in its direct vicinity and this implies potential for systemic radiotherapy with 99mTc complexes. 相似文献
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A.R. Adhikari G. Georgiev K. Sigdel G.S. Iannacchione K. Lozano M. Chipara 《Polymer Engineering and Science》2012,52(2):408-413
The effect of carbon nanofiber on the thermal behavior of poly(ethylene‐co‐propylene) (PEP) as revealed by differential scanning calorimetry and thermogravimetric analysis is reported. Analysis showed faster crystallization of PEP at higher temperature upon cooling with the increase of carbon nanofiber (CNF) content. The crystallization behavior changed to a single narrow crystallization peak as compared with the broad double crystallization peak of the neat polymer. This demonstrates the nucleation ability of CNF to induce crystals with more uniform distribution. The modified‐Avrami approach was used to study the crystallization behavior. We found that the crystallization rate constant increased with addition of CNFs. The dimensionality of crystal growth was found not to depend significantly on the content of CNF. Thermal degradation in air was monitored using thermogravimetric analysis and observed that the incorporation of nanofiber greater than 2.4 vol% improves thermal stability of PEP. All these results indicate that CNFs can significantly help polymer processing and increase thermal stability of polymers. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers 相似文献
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Abstract Computer simulation of colour parameters of single layer coatings, transparent in the visible spectral region, is carried out with purpose of film thickness d and optical dispersion n(λ) determination. An approach for determination of characteristics of a transparent thin film from transmitted light colour coordinates is proposed. The region in which the proposed method is applicable is estimated from comparison between film characteristics obtained from the colour coordinates and envelope methods for RF deposited transparent BaTiO3 thin films. 相似文献
10.
Leopold Jirovetz Gerhard Buchbauer Albena S. Stoyanova Evgenii V. Georgiev & Stanka T. Damianova 《International Journal of Food Science & Technology》2005,40(3):305-310
The essential oil of seeds of cumin (Cuminum cyminum L.) from Bulgaria stored for more than 35 years was analyzed by physicochemical methods, GC, GC‐MS and olfactometry and its antimicrobial activity tested using different strains of microorganisms. More than sixty constituents of this cumin oil could be identified as essential volatiles, responsible for the pleasant fresh, clean, spicy (typical cumin‐like) odour of a high quality product. Cumin aldehyde (36%), β‐pinene (19.3%), p‐cymene (18.4%) and γ‐terpinene (15.3%) were the principal compounds found. Antimicrobial testing showed high activity of the essential C. cyminum oil against the mold Aspergillus niger, the Gram (+) bacteria Bacillus subtilis and Staphylococcus epidermidis as well as the yeast Saccharomyces cerevisiae and Candida albicans. 相似文献