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61.
We consider a model describing the combustion of a coal particlein a fluidized bed, in which attrition plays a dominant role.The model consists of (1) a quasi-linear elliptic equation forthe oxygen concentration, supplemented by boundary conditionson the moving surface representing the burning particle interface,(2) an evolution equation for the carbon consumption, and (3)an equation governing the motion of the interface in terms ofa specified function of the carbon consumption at the interface.We prove a global existence and uniqueness result, togetherwith a priori bounds for the solution; the existence of travellingwaves will also be established. 相似文献
62.
VINCENZO DE FILIPPIS MOHD ARIF RAZA NADEEM UR REHMAN 《Proceedings Mathematical Sciences》2017,127(1):91-98
Let R be a prime ring of characteristic different from 2, C its extended centroid, d a nonzero derivation of R, f(x 1, . . . , x n ) a multilinear polynomial over C, ρ a nonzero right ideal of R and m > 1 a fixed integer such that for all r 1, . . . , r n ∈ρ. Then either [f(x 1,…,x n ),x n+1]x n+2 is an identity for ρ or d(ρ)ρ = 0.
相似文献
$$\qquad \left ([d(f(r_{1},\ldots ,r_{n})),f(r_{1},\ldots ,r_{n})]\right )^{m}=[d(f(r_{1},\ldots ,r_{n})),f(r_{1},\ldots ,r_{n})] $$
63.
采用溶剂热方法制备了La0.789Yb0.20Ho0.001Tm0.01F3纳米立方体,并利用粉末X射线衍射仪、透射电子显微镜和X射线能谱仪表征了其组成、结构和形貌,用荧光分光光度计测量了样品的室温上转换发射光谱,结果表明,样品具有红、绿和蓝色3个发射带,其辐射跃迁分别归属于Tm3+的1G4→3H6(蓝色)和1G4→3... 相似文献
64.
A method to obtain (approximate) analytical expressions for the radial distribution functions in a multicomponent mixture of additive hard spheres that was recently introduced is used to obtain the direct correlation functions and bridge functions in these systems. This method, which yields results practically equivalent to the generalized mean spherical approximation and includes thermodynamic consistency, is an alternative to the usual integral equation approaches and requires as input only the contact values of the radial distribution functions and the isothermal compressibility. Calculations of the bridge functions for a binary mixture using the Boublik-Mansoori-Carnahan-Starling-Leland equation of state are compared to parallel results obtained from the solution of the Percus-Yevick equation. We find that the conjecture recently proposed by Guzman and del Rio (1998, 98, Molec. Phys., 95, 645), stating that the zeros of the bridge functions occur approximately at the same value of the shifted distance for all pairs of interactions, is at odds with our results. Moreover, in the case of disparate sizes, even the Percus-Yevick bridge functions do not have this property. It is also found that the bridge functions are not necessarily non-positive. 相似文献
65.
E. SICILIA G. DE LUCA S. CHIODO N. RUSSO P. CALAMINICI A. M. KOSTER 《Molecular physics》2013,111(12):1039-1051
Density functional calculations of the electric field gradient tensor at the nitrogen nucleus in 13 test molecules, containing 14 nitrogen sites, have been performed using the linear combination of Gaussian-type orbital Kohn-Sham density functional theory (LCGTO-KSDFT) approach. Local and gradient corrected functionals were used for all-electron calculations. All the molecular structures were optimized at their respective levels of theory with extended basis sets. Calibrated 14N nuclear quadrupole moments were obtained through a fitting procedure between calculated electric field gradients and experimental nuclear quadrupole coupling constants of the test set of molecules for each basis set and functional considered. With these calibrated 14N nuclear quadrupole moments, the nuclear quadrupole coupling constants of the following selected systems were determined: fluoromethylisonitrile, pyridine, pyrrole, imadazole, pyrazole, 1,8-bis(dimethyl-amino)naphthalene, cyclotetramethylenetetranitramine, cocaine and heroin. 相似文献
66.
(Molecular Physics, 1994, 83, 309–326) 相似文献
67.
68.
SIMONA BADILESCU † RICARDO BICCA DE ALENCASTRO † HOA LE-THANH GUY RlCHER CAMILLE SANDORFY PIERRE-PAUL VAUDREUIL DANIEL VOCELLE 《Photochemistry and photobiology》1989,49(3):313-318
The hydrogen bonding-protonation equilibrium for retinyl Schiff base/propionic acid or 3-chloropropionic acid systems was examined by Fourier transform infrared spectroscopy in non polar solutions at temperatures ranging from 25 degrees C to about -150 degrees C. The spectra give evidence for the gradual increase in the degree of protonation as temperature is lowered. The bearing of this on applying low temperature spectroscopic results to physiological conditions in rhodopsin research is discussed. 相似文献
69.
We study properties of dynamic discrete-time linear systemswith the input or the state constrained to have integer components.The reachability of input-constrained systems is investigated,and consistency conditions for state-constrained systems aregiven. 相似文献
70.
本文首次报道了由钾分子-原子系统的混合激发和碰撞能量转移过程产生4F→3D受激辐射以及由钾原子的4S→4F偶极禁戒双光子共振产生4F→3D受激辐射和四波混频的研究结果。 相似文献