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31.
Low temperature infrared spectra of light induced metastable states MS1 and MS2 of the nitroprusside anion in Na(2)[Fe(CN)(5)NO].2H(2)O, isotopically normal and substituted with (15)NO and N(18)O, are presented and discussed. As a consequence of the relatively high population of the MS2 state achieved by further irradiation with 1064 nm light of samples previously irradiated with 488.0 nm light, new bands were seen for the first time, and others, previously reported, were confirmed. The comparison of the spectral data obtained for the FeNO moiety of the isotopically normal as well as of the (15)NO and N(18)O substituted anion with the results of quantum chemical (DFT) calculations support the assignment of the bands which appear after successive irradiations to MS1, the linear Fe(eta(1)-ON) linkage isomer, and to MS2, the side-bound Fe(eta(2)-NO) isomer. 相似文献
32.
With a view to the use of picolinealdehyde salicyloylhydrazone as analytical reagent, a study of the physical properties and chemical reactions of this substance has been carried out. It reacts with nickel (λmax = 375 nm, ? = 3.9 × 104M?1cm?1) or zinc (λmax = 365 nm, ? = 4.8 × 104M?1cm?1) to produce a yellow 1:2 complex in both cases. Spectrophotometric determinations of trace amounts of nickel and zinc have been established. 相似文献
33.
Summary An absorption method for the collection of acid and condensable volcanic gases is described. A Cd(OH)2 suspension allows the simultaneous sampling of sulfide and sulfur dioxide. A complete scheme for chemical analysis of H2O, CO2, H2S, SO2, HCl and HF is presented.The method is relatively simple and accurate and requires only simple equipment. Moreover, separate samples of the condensable part of the volcanic gas may be used for analysis of trace elements.
Probenahme und Analyse vulkanischer Gase
Zusammenfassung Eine Absorptionsmethode zur Probenahme saurer und kondensierbarer Vulkangase wurde beschrieben. Eine Cd(OH)2-Suspension ermöglicht die gleichzeitige Probenahme von H2S und SO2. Ein Analysenschema für die chemische Analyse von H2O, CO2, H2S, SO2, HCl und HF wurde angegeben. Das Verfahren ist relativ einfach und genau; es erfordert nur eine einfache Ausrüstung. Proben des kondensierbaren Anteils der Gase dienen zur Bestimmung der Spurenanteile.相似文献
34.
A stochastic method of optimization, which combines simulated annealing with simplex, is implemented to fit the parameters of a simple model potential. The main characteristic of the method is that it explores the whole space of the parameters of the model potential, and therefore it is very efficient in locating the global minimum of the cost function, in addition to being independent of the initial guess of the parameters. The method is employed to fit the complex intermolecular potential energy surface of the dimer of water, using as a reference the spectroscopic quality anisotropic site-site potential of Feller et al. The simple model potential chosen for its reparameterization is the MCY model potential of Clementi et al. The quality of the fit is assessed by comparing the geometry of the minimum, the harmonic frequencies, and the second virial coefficients of the parameterized potential with the reference one. Finally, to prove more rigorously the robustness of this method, it is compared with standard nonstochastic methods of optimization. 相似文献
35.
From the de Broglie matter wave hypothesis and Planck’s energy quantization law, and assuming conservation of energy in the
absorption of a photon and its consequent conversion to kinetic energy of motion by a material particle initially at rest,
one can deduce a simple mathematical relationship between the wavelength λ (or frequency ν), of the photon absorbed by the
particle at rest, and the resulting de Broglie matter wave length, λD, of the particle with kinetic energy of motion of mv2/2. The relationship so deduced, λD∝√λ, suggests that visible wavelengths of light, from about 4000 ?, in the violet, to beyond about 7000 ?, in the red, on
absorption by an electron at rest, lead to material electron wavelengths, λD, of the order of the size of the electron transfer proteins seen in the photosynthetic reaction centers of photosynthesizing
organisms, at about a size of 50–100 ?. In addition to understanding the mechanism of photosynthesis as a material wave mediated
phenomenon, further areas of importance of the relations pointed out in this paper are in the design of experiments to gain
a deeper understanding of the basic tenets of wave mechanics, and in the use of tunable lasers to probe various properties
of material waves, and to precisely control their properties for applications including lithography. 相似文献
36.
Francisco M. Ferndez Eduardo A. Castro 《International journal of quantum chemistry》1982,21(5):875-884
New formal results regarding the hypervirial analysis of enclosed systems are given. Novel applications are presented and several previous equations are reformulated in a more appropriate form. 相似文献
37.
Alconchel S Sapiña F Martínez E 《Dalton transactions (Cambridge, England : 2003)》2004,(16):2463-2468
The molybdenum bimetallic interstitial carbides Fe(3)Mo(3)C and Co(3)Mo(3)C have been synthesized by temperature-programmed reaction (TPR) between the molybdenum bimetallic interstitial nitrides Fe(3)Mo(3)N and Co(3)Mo(3)N and a flowing mixture of CH(4) and H(2) diluted in Ar. These compounds have been characterized by X-ray diffraction, laser Raman spectroscopy, elemental analysis, energy dispersive analysis of X rays, thermal analysis (in air) and scanning electron microscopy (field emission). Their structures have been refined from X-ray powder diffraction data. These carbides crystallize in the cubic system, space group Fd3m[a= 11.11376(6) and 11.0697(3)[Angstrom] for Fe and Co compounds, respectively]. 相似文献
38.
Ramiro Pino Olivier Bokanowski Eduardo V. Ludeña Roberto López Boada 《Theoretical chemistry accounts》2007,118(3):557-561
Bearing in mind the insight into the Hohenberg–Kohn theorem for Coulomb systems provided recently by Kryachko (Int J Quantum
Chem 103:818, 2005), we present a re-statement of this theorem through an elaboration on Lieb’s proof as well as an extension
of this theorem to finite subspaces.
Contribution to the Serafin Fraga Memorial Issue. 相似文献
39.
de Namor AF Chahine S Castellano EE Piro OE Jenkins HD 《Chemical communications (Cambridge, England)》2005,(30):3844-3846
An additive thermodynamic contribution of pendant arms to the complexation of calixarene derivatives with mercury(II) in acetonitrile is for the first time demonstrated. 相似文献
40.
de Arquer María Ponte Borja Pino Raúl 《Central European Journal of Operations Research》2022,30(4):1307-1336
Central European Journal of Operations Research - We study a hybrid system where the demand of customers can be satisfied by both manufacturing new products and remanufacturing used products. To... 相似文献