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841.
Suppose that g(f) are bi-parameter Littlewood-Paley square functions which were introduced by H. Martikainen. It is known that the boundedness and the boundedness of g(f) have been proved by H. Martikainen and by Z. Li and Q. Xue, respectively. In this paper, we apply the vector-valued theory, the atomic decomposition of product Hardy spaces, and Journe's covering lemma to show that g(f) are bounded from to with p smaller than 1. 相似文献
842.
The correlations between the pressure sensitivity and the fragility/glass transition temperature have been addressed in various bulk metallic glasses in the present work. The results demonstrate that the pressure sensitivity of bulk metallic glasses is closely related to both the fragility index (m) and the glass transition temperature (Tg). The physical origin of the correlations has been discussed from their disordered structure, which is determined by the glass transition behavior and the glass transition temperature. 相似文献
843.
考虑信用风险模型的破产问题,研究Gerber-Shiu贴现罚函数,通过引进辅助模型,运用概率论的分析方法得到了其所满足的积分方程.相应地可以得到该模型下的破产概率、破产时刻前赢余和破产时刻赤字的联合分布及其边际分布,进一步完善了YangHailiang发表的相关问题的结果. 相似文献
844.
845.
Consider the determination of Dirichlet-to-Neumann (D-to-N) map from the far-field pattern in inverse scattering problems, which is the key step in some recently developed inversion schemes such as probe method. Essentially, this problem is related to the reconstruction of the scattered wave from its far-field data. We firstly prove the well-known uniqueness result of the D-to-N map from the far-field pattern using a new scheme based on the mixed reciprocity principle. The advantage of this new proof scheme is that it provides an efficient algorithm for computing the D-to-N map, avoiding the numerical differentiation for the scattered wave. Then combining with the classical potential theory, a simple and feasible regularizing reconstruction scheme for the D-to-N map is proposed. Finally the stability estimate for the reconstruction with noisy input data is rigorously analyzed. 相似文献
846.
847.
A new light beam termed as a cosh-squared-Gaussian beam (ChSGB) which may be one of solutions of the paraxial wave equation for propagation in complex optical systems has been introduced. Their beam propagation factor (M2-factor) is derived and schemes to generate this light beams are proposed. 相似文献
848.
《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(5):759-763
The feasibility of using internal standardization (IS) to correct for interferences in hydride generation with in situ trapping in graphite furnace was evaluated. Arsenic was chosen as internal standard for Sb determination and Ir was used as permanent modifier. Fluctuations in the main parameters that affect the analytical results were minimized by IS and an effective contribution was verified in the studies of liquid phase interferences. Cobalt and Ni2+ were selected to illustrate the potential use of IS on the correction of interference by transition metals. The application of IS allows the Sb determination in samples containing up to 20-fold higher concentration of the Co2+ and Ni2+ when compared to the procedure without IS. The relative standard deviation of measurements varied from 0.3% to 0.7% and from 1.1% to 3.2% with and without IS, respectively. Recoveries within 92% and 107% of spiked aqueous solution containing Sb(III) and Sb(V) were found. 相似文献
849.
ZENGQINGGUANG 《高校应用数学学报(英文版)》1997,12(1):117-125
In this paper, we provide a new generalized gradient projection algorithm for nonlinear programming problems with linear constraints. This algorithm has simple structure and is very practical and stable. Under the weaker assumptions, we have proved the global convergence of our algorithm. 相似文献
850.
Topological steric effect index and its application 总被引:3,自引:0,他引:3
This paper proposed a Topological Steric Effect Index (TSEI) of a group based on the relative specific volume of the reaction center screened by the atoms of the substituents. Investigated results show good correlations between the parameter TSEI and the dihedral angles between both phenyl rings determined by photoelectron spectroscopy for 7 alkylbiphenyl compounds and calculated by a molecular mechanics force field for 78 alkylbiphenyl compounds, whose correlation coefficients are 0.9912 and 0.9845, respectively. The TSEI value of the group is easily calculated and has a clear physical meaning. In addition, it is correlated well to dihedral angles of the 1,2-disubstituted benzene compounds, stereoselectivity of organomagnesium compounds addition to some cyclohexanones and cyclopentanones, and the relative rates of some SN2 reactions. 相似文献