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121.
用特征值-特征向量法对甲烷-空气燃烧时NOX生成的化学反应机理进行了简化,得到了仅由15个基元以应组成的简化反应模型。对比计算结果表明,该模型能在较宽燃空比内与全面模型很好吻合,因而可望用于燃烧过程数值模拟时对NOX生成的预测 相似文献
122.
Keller Hildegard Langer Elisabeth Lehner Harald Derflinger Gerhard 《Theoretical chemistry accounts》1978,49(2):93-100
The Algebraic Theory of Chirality Functions is derived by means of exclusively qualitative considerations. Hence, the significance of quantitative results is questionable. Moreover the construction of “Näherungsansätze” (”Approximation-Ansatz”), which may be interpreted as semiempirical methods, is achieved on the basis of plausibility and mathematical simplicity. Since physical arguments are not included, the consistency or inconsistency of “Näherungsansätze” with experimental results do not justify direct physical conclusions. 相似文献
123.
124.
Convex programs with an additional reverse convex constraint 总被引:2,自引:0,他引:2
H. Tuy 《Journal of Optimization Theory and Applications》1987,52(3):463-486
A method is presented for solving a class of global optimization problems of the form (P): minimizef(x), subject toxD,g(x)0, whereD is a closed convex subset ofR
n
andf,g are convex finite functionsR
n
. Under suitable stability hypotheses, it is shown that a feasible point
is optimal if and only if 0=max{g(x):xD,f(x)f(
)}. On the basis of this optimality criterion, the problem is reduced to a sequence of subproblemsQ
k
,k=1, 2, ..., each of which consists in maximizing the convex functiong(x) over some polyhedronS
k
. The method is similar to the outer approximation method for maximizing a convex function over a compact convex set. 相似文献
125.
For the weakly coupled lattice
3
6
theory in a hierarchical model approximation a nonperturbative renormalization group analysis in the spirit of Gawedzki and Kupiainen is performed to study the flow of the effective actions. We deduce a domain of attraction to the tricritical (Gaussian) fixed point. The two relevant coupling constants of the problem are controlled by analytic continuation to complex domains, tracing their images under the renormalization group iterations. 相似文献
126.
An Improvement of IAP OGCM for the Pacific Ocean Circulation and Its Simulated Results 总被引:2,自引:0,他引:2
Based on the oceanic CCM with standard stratification subtraction but without the rigid-lid approximation designed in Institute of Atmospheric Physics (IAP OGCM) and its numerical modelings for the large-scale ocean circulation, a numerical model for the Pacific Ocean is developed with higher resolution (2.5°×2° in the longitude and latitude, 8 layers in the vertical),the realistic coastline geometry,the smoothed bottom topography and the Richardson number dependent vertical mixing parameterization.The splitting time integration scheme of the barotropic and baroclinic modes is adopted in the model. The numerical simulation under the annual mean atmospheric forcing shows that the model performance is improved substantially compared with the previous low resolution version.This free surface model,in particular, successfully simulates the well-known ridge-trough structure in the sea level, i.e. the equatorial trough, the equatorial ridge near 3°N, the north countercurrent trough between 8°N and 10°N, 相似文献
127.
Five different structures of CH5
+ and one structure of CH5
– are calculated using a gaussian basis both in the SCF approximation and with the inclusion of electron correlation in the independent electron pair approximation (IEPA). While on SCF level the C
sstructure of CH5
+ has to lowest energy, the energy difference between the C
sand C
2vstructures becomes negligible if correlation is included. In contrast to this the approach of a proton to CH4 at large and intermediate distances is most favorable towards a corner of the CH4 tetrahedron which means a structure. The decomposition of CH5
+ into CH3
+ and H2 requires 20kcal/mol on SCF level and 40 kcal/mol if correlation is included. 相似文献
128.
Recent developments in quantitative surface analysis by Auger (AES) and x-ray photoelectron (XPS) spectroscopies are reviewed and problems relating to a more accurate quantitative interpretation of AES/XPS experimental data are discussed. Special attention is paid to consideration of elementary physical processes involved and influence of multiple scattering effects on signal line intensities. In particular, the major features of core-shell ionization by electron impact, Auger transitions and photoionization are considered qualitatively and rigorous approaches used to calculate the respective transition probabilities are analysed. It is shown that, in amorphous and polycrystalline targets, incoherent scattering of primary and signal Auger and photoelectrons can be described by solving analytically a kinetic equation with appropriate boundary conditions. The analytical results for the angular and energy distribution, the mean escape depth, and the escape probability as a function of depth of origin of signal electrons as well as that for the backscattering factor in AES are in good agreement with the corresponding Mote Carlo simulation data. Methods for inelastic background subtraction, surface composition determination and depth-profile reconstructions by angle-resolved AES/XPS are discussed. Examples of novel techniques based on x-ray induced photoemission are considered. 相似文献
129.
A comparative quantum-chemical analysis of the electronic structures and spectroscopic parameters of the cycloalkanes C3H6, C4H8, C5H10, and C6H12 and their silicon analogs Si3H6, Si4H8, Si5H10 and Si6H12 was performed in the framework of the SCF MO LCAO method in the INDO approximation. Qualitative interpretation of “abnormal”
ionization potentials and energies of electronic absorption spectra of cyclopolysilanes has been given.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1105–1108, June, 1997. 相似文献
130.
A new approach to calculating the equilibrium characteristics of the adsorption of noble gases on the amorphous surfaces of
adsorbents was developed and applied to the Ar−TiO2(rutile) system. Intermolecular adsorbate-adsorbate interactions are taken into account for the nearest neighbors in the quasi-chemical
approximation. The lattice energy parameters of all interactions of the model are determined from the Lennard-Jones potential
(12-6). The formation of amorphous TiO2(rutile) surface includes completion of the surface layers and partial removal of the surface oxygen ions. The quality of
the amorphization procedure was confirmed by the experimentally measured heats and isotherms of adsorption of the system under
study.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1109–1118, June, 1997. 相似文献