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91.
《Journal of the Egyptian Mathematical Society》2014,22(2):280-285
In this paper, we propose a new three-level implicit nine point compact finite difference formulation of O(k2 + h4) based on non-polynomial tension spline approximation in r-direction and finite difference approximation in t-direction for the numerical solution of one dimensional wave equation in polar co-ordinates. We describe the mathematical formulation procedure in details and also discuss the stability of the method. Numerical results are provided to justify the usefulness of the proposed method. 相似文献
92.
We present two novel two-step explicit methods for the numerical solution of the second order initial value problem on a variable mesh. In the case of a constant mesh the method is superstable in the sense of Chawla (1985). Numerical experimentation is provided to verify the stability analysis. 相似文献
93.
F. J. Gil Llambías N. Escalona C. Pfaff C. Scott J. Goldwasser 《Reaction Kinetics and Catalysis Letters》1999,66(2):225-229
Apparent surface coverage (ASC) of a series of tungsten-alumina catalysts was determined by the electrophoretic migration
method (EM). A linear increase in W coverage with increasing W loading (up to 13.1 wt.% W) was observed. The results were
in close agreement with those obtained previously by ion scattering spectroscopy (ISS) and low temperature CO adsorption. 相似文献
94.
Marcin Płosiński Tomasz Laskowski Paweł Sowiński Jan Pawlak 《Magnetic resonance in chemistry : MRC》2012,50(12):818-822
The absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previously elaborated general procedure, consisting of DQF‐COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. The structure of mycoheptin A2 without stereochemistry of its aglycone has been reported before. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
95.
A lower triangular matrix with nonzero principal diagonal entries is called a triangle. In this paper we obtain the sufficient conditions for ∑anλn to be summable ∣A∣k whenever ∑an is summable ∣T∣k for a triangle T. 相似文献
96.
97.
Serdar Karademir 《Linear and Multilinear Algebra》2013,61(6):707-710
In this note we formulate necessary and sufficient conditions for strong solvability and feasibility of systems of linear interval equations in terms of absolute value inequalities. 相似文献
98.
磁约束等离子体中杂质(特别是高Z杂质)的存在将大大增强等离子体辐射功率损失,破坏等离子体的约束性能。杂质行为的定量研究首先要求对杂质测量的光谱诊断系统进行绝对强度标定,获得灵敏度响应曲线。介绍了EAST托卡马克上的快速极紫外光谱仪系统绝对强度的原位标定方法。在波长范围20~150Å内,通过对比极紫外(EUV)波段连续轫致辐射强度的计算值和测量值得到光谱仪的绝对强度标定。在此过程中,首先由(523±1) nm范围内可见连续轫致辐射强度的绝对测量值计算出有效电荷数Zeff,进而结合电子温度和密度分布计算EUV波段连续轫致辐射强度;EUV波段连续轫致辐射强度的测量值即为不同波长处探测器的连续本底计数扣除背景噪声计数值。对于较长波段范围130~280Å,通过对比等离子体中类锂杂质离子(Fe23+,Cr21+,Ar15+)和类钠杂质离子(Mo31+,Fe15+)发出的共振谱线对(跃迁分别为1s22s 2S1/2-1s22p 2P1/2, 3/2及2p63s 2S1/2-2p63p 2P1/2, 3/2)强度比的理论和实验值进行相对强度标定。其中共振谱线对强度比的理论值由辐射碰撞模型计算得到,模型中处在各个能级的离子数主要由电子碰撞激发,去激发以及辐射衰变三个过程决定。两种方法相结合,实现了光谱仪20~280Å范围的绝对强度标定。考虑轫致辐射、电子温度及电子密度的测量误差,绝对标定误差约为30%。在绝对标定的基础上,我们对杂质特征谱线强度进行绝对测量,并将测量结果与杂质输运程序结合ADAS(Atomic Data and Analysis Structure)原子数据库计算得到的模拟值进行比较,进而估算等离子体中的杂质浓度。 相似文献
99.
Alberto Paradela Miguel Marcilla Laura Ferreira Marisol Fernández Francisco García-del Portillo 《Talanta》2010,80(4):1496-3398
An evaluation of the ICPL (isotope-coded protein labeling) non-isobaric labeling technique was performed using two different biological models. Two samples containing phage T4 capsids were mixed in a 1:1 ratio after being labeled with the light or heavy versions of the ICPL reagent. The analysis of this proteome demonstrated the feasibility of this approach for differential quantitative proteomics and was employed to optimize the experimental parameters of the ICPL workflow. ICPL-mediated analysis of two more complex proteomes, those of a Salmonella enterica serovar Typhimurium virulent strain and an isogenic attenuated mutant, and its comparison with the results obtained in a 2D-PAGE “classical” approach confirmed that ICPL is a valuable alternative to other labeling techniques currently in use. In addition, our results suggest that labeling at the peptide level instead of following the standard ICPL workflow should increase both the number of proteins quantified and the reliability of the quantification. 相似文献
100.
1 INTRODUCTIONOrganophosphorus compounds are ubiquitous in nature and they have broad applications in the fields of agriculture and medicine. During the past two decades, (-ketophosphonates and their derivatives have attracted considerable attention because these compounds are endowed with special physical, chemical and pharmacological properties due to the proximity of the carbonyl and the phosphoryl groups[1~6]. For example, it is well known that phosphonoformic acid (PFA) is effectiv… 相似文献