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81.
The spectral study of an optical modulator based on the frustrated total internal reflection is presented under static and dynamic conditions. An optical modulator based on macroscopic moving parts makes spectrometers voluminous and has low compactness. The use of static or quasi-static optical modulators, such as the one proposed in this paper, avoids these problems. The study under static conditions reveals that the modulator equalises the spectral emittance of a black body. The modulation efficiency is defined by comparing the modulator with an ideal square chopper. Study under dynamic conditions reveals spectral criteria that must be met in the design of the mechanical system of the modulator to shift the maximum value of the modulation efficiency to the desired wavelength. 相似文献
82.
Katarzyna Kucwaj-Brysz Anna Dela Sabina Podlewska Marek Bednarski Agata Siwek Grzegorz Sataa Kinga Czarnota Jadwiga Handzlik Katarzyna Kie-Kononowicz 《Molecules (Basel, Switzerland)》2021,26(22)
Several studies confirmed the reciprocal interactions between adrenergic and serotoninergic systems and the influence of these phenomena on the pathogenesis of anxiety. Hence, searching for chemical agents with a multifunctional pharmacodynamic profile may bring highly effective therapy for CNS disorders. This study presents a deep structural insight into the hydantoin-arylpiperazine group and their serotonin/α-adrenergic activity. The newly synthesized compounds were tested in the radioligand binding assay and the intrinsic activity was evaluated for the selected derivatives. The computer-aided SAR analysis enabled us to answer questions about the influence of particular structural fragments on selective vs. multifunctional activity. As a result of the performed investigations, there were two leading structures: (a) compound 12 with multifunctional adrenergic-serotonin activity, which is a promising candidate to be an effective anxiolytic agent; (b) compound 14 with high α1A/α1D affinity and selectivity towards α1B, which is recommended due to the elimination of probable cardiotoxic effect. The structural conclusions of this work provide significant support for future lead optimization in order to achieve the desired pharmacodynamic profile in searching for new CNS-modulating agents. 相似文献
83.
Novel linear oligoheterocycles based on substituted tetrazines are described. The desired compounds have been accomplished by a variation of the original Pinner [Ann. Chem., 297 (1897) 221] synthesis in which the aromatic nitrile reacted with hydrazine in an aqueous solution to give bis(pyrrolyl)tetrazines or bis(phenyl)tetrazines. The bis(phenyl)tetrazines reacted with 3,4-ethylenedioxy-2-(trimethyltin)thiophene or 2-(trimethyltin)thiophene in the presence of Pd(PPh3)2Cl2 or Pd(PPh3)4 as catalyst to give the desired compounds. Quantum-chemical calculations were performed to assess the usefulness of the synthesized compounds for electropolymerization. Studies have indicated qualitative difference between bis-pyrrole tetrazine and bis-phenyl tetrazines regarding the electronic density rearrangement due to the loss of an electron. 相似文献
84.
85.
86.
Jadwiga Skupiska Monika Karpiska Leszek Wachowski Magdalena Hofman 《Reaction Kinetics and Catalysis Letters》2004,82(2):311-316
A simple catalytic system containing metallic palladium, iron and iodine has been shown to be very active in the carbonylation
of nitrobenzene to carbamate. The influence of the components of the catalytic system studied on its selectivity and activity
has been established. It has been found that the catalytic activity of palladium supported on carbon (using both lignite coal
and bituminous coal) was not lower than the activity of metallic palladium.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
87.
A microfluidic analytical system for the separation and detection of organic peroxides, based on a microchip capillary electrophoresis device with an integrated amperometric detector, was developed. The new microsystem relies on the reductive detection of both organic acid peroxides and hydroperoxides at -700 mV (vs. Ag wire/AgCl). Factors influencing the separation and detection processes were examined and optimized. The integrated microsystem offers rapid measurements (within 130 s) of these organic-peroxide compounds, down to micromolar levels. A highly stable response for repetitive injections (RSD 0.35-3.12%; n = 12) reflects the negligible electrode passivation. Such a "lab-on-a-chip" device should be attractive for on-site analysis of organic peroxides, as desired for environmental screening and industrial monitoring. 相似文献
88.
András Büki Tamás Perger Tamás Turányi Ulrich Maas 《Journal of mathematical chemistry》2002,31(4):345-362
Effective procedures for the reduction of reaction mechanisms, including the intrinsic low-dimensional manifold (ILDM) and the repro-modelling methods, are all based on the existence of very different time scales in chemical kinetic systems. These two methods are reviewed and the advantages and drawbacks of them are discussed. An algorithm is presented for the repro-modelling based generation of ILDMs. This algorithm produces an unstructured table of ILDM points, which are then fitted using spline functions. These splines contain kinetic information on the behaviour of the chemical system. Combustion of hydrogen in air is used as illustrative example. Simulation results using the fitted model are compared with the outcome of calculations based on the detailed reaction mechanism for homogeneous explosions and 1D laminar flames. 相似文献
89.
Sensitivity analysis of complex kinetic systems. Tools and applications 总被引:21,自引:0,他引:21
Tamás Turányi 《Journal of mathematical chemistry》1990,5(3):203-248
Sensitivity analysis investigates the effect of parameter change on the solution of mathematical models. In chemical kinetics, models are usually based on differential equations and the results are concentration-time curves, reaction rates, and various kinetic features of the reaction. This review discusses in detail the concentration sensitivity, rate sensitivity, and feature sensitivity analysis of spatially homogeneous constant-parameter reaction systems. Sensitivity analyses of distributed parameter systems and of stochastic systems are also briefly described. Special attention is paid to the interpretation of sensitivity coefficients which can provide information about the importance and interconnection of parameters and variables. Applications of sensitivity analysis to uncertainty analysis, parameric scaling, parameter estimation, experimental design, stability analysis, repro-modeling, and investigation and reduction of complex reaction mechanisms are discussed profoundly. 相似文献
90.
Stefan Minc Jadwiga Jastrzȩbska Maria Jurkiewicz-Herbich 《Journal of Electroanalytical Chemistry》1975,65(1):351-359
The adsorption of thiourea on mercury has been investigated by capacitance measurements in three water + methanol mixtures, having various mole fractions of methanol.The back integration method was employed to obtain the curves of surface charge densities at the mercury surface for different concentrations of thiourea in the solution.As a test of specific adsorption in the systems studied the Esin-Markov plots were used. 相似文献