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81.
本文建立了解二阶双曲型方程的一种新数值方法一再生核函数法.利用再生核函数,直接给出每个离散时间层上近似解的显式表达式.此方法的优点是:计算格式绝对稳定,且可显式求解;利用显式表达式,可实现完全并行计算等文中对近似解的收敛性和稳定性进行了理论分析,并给出数值算例.  相似文献   
82.
谢胜利 《数学杂志》1998,18(2):155-160
在不主紧型条件和耗散型条件的情形下,得到了Banach空间中一类非线性积分,微分方程的逼近解。  相似文献   
83.
This paper introduces the principles, instrumentation, implementation, and industrial applications of an on-line thermal neutron prompt-gamma element analysis system (using a252Cf neutron source, Am–Be neutron source, or neutron generator). The energy resolution of the system at the H prompt-gamma full-energy photopeak (2.22325 MeV) is 3.6 keV. The concentration measurement error of Al2O3, FeO3, CaO, and SiO2 is ±0.3%, ±0.1%, ±0.4%, and ±0.4%, respectively. The system has been tested on-site at both the Shandong and the Zhengzhou Aluminium Works. Our preliminary on-site measurements confirm that the stability, reliability, measurement range, and accuracy of the system can meet the requirements of the aluminium production process. Facilitation of this measurement at aluminium plants is expected to reduce plant costs by over 3 million dollars annually through reduced energy consumption, more rapid qualification of pulps being mixed during the production process, and in reduced labor costs.Other participants of Shandong and Zhenghou Aluminium Works are: Wang Aili, Zengshen, Dei Jianguo and Lu Jinnan, Wang Deyu, Jin Hequan.  相似文献   
84.
85.
The title compound, [HgCl2(C10H8N2)]n, features two‐dimensional [HgCl2(4,4′‐bipy)]n neutral networks (4,4′‐bipy is 4,4′‐bipyridine), based on an octahedral Hg atom coordinated by four μ2‐Cl atoms and two μ2‐4,4′‐bipy ligands in trans positions, yielding a HgCl4N2 octahedron. The structure has mmm symmetry about the Hg atoms, with most of the atoms on at least one mirror plane, but the unsubstituted C atoms of the 4,4′‐bipy rings are disordered across a mirror plane. Photoluminescent investigations reveal that the title compound displays a strong emission in the green region, which probably originates from a ligand‐to‐ligand charge‐transfer transition.  相似文献   
86.
本文得到了正定Hermitian阵的Hadamard积的Schur补的一些不等式,进而,给出了他们的一些应用,这些改进了近期的一些结束.  相似文献   
87.
基于零点的函数K图和dj图的转换   总被引:9,自引:7,他引:2       下载免费PDF全文
介绍了函数的最大项展开式和CRM展开式及其图形表示,提出函数K图和dj图的零点的概念,并以此为基础讨论了基于零点的函数K图和dj图之间的转换方法。  相似文献   
88.
原子吸收法在有机分析中的应用(Ⅵ)香烟中氢氰酸的分析谢志海,郎惠云,高云(西北大学化学系,西安,710069)关键词:氢氰酸,测定,原子吸收光谱香烟中的尼古丁,烟焦油等含氮有机物燃烧后将产生氢氰酸,吸入人体后极为有害。国外在这方面的研究始于七十年代,...  相似文献   
89.
The adsorption of alginate (Alg) onto the surface of in water dispersed Fe3O4 nanoparticles and zeta potential of alginate-coated Fe3O4 nanoparticles have been investigated to optimize the colloidal stability of Alg-coated Fe3O4 nanoparticles. The adsorption amount of Alg increased with the decrease of adsorption pH. The zeta potential of Fe3O4 nanoparticles shifted to a lower value after adsorption of Alg. The lower adsorption pH was the lower zeta potential of Fe3O4 nanoparticles became. The Alg-coated Fe3O4 nanoparticles were found to be stabilized by steric and electrostatic repulsions. Those prepared at pH 6 were not stable around pH 5, and those prepared at pH 4 became unstable at pH below 3.5. Alg of Mw 45 kDa was a little bit more adsorbed onto nanoparticles surface than that of Mw 24 kDa. An average Fe3O4 core size of 9.3 ± 1.7 nm was found by transmission electronic microscopy. An average hydrodynamic diameter of 30-150 nm was measured by photon correlation spectroscopy. However, an average core size of 10 nm and an average hydrodynamic diameter of 38 nm were estimated from the magnetization curve of the concentrated magnetic fluids (MFs). The maximum available saturation magnetization of MFs was about 3.5 kA/m.  相似文献   
90.
In this paper, the pulsed injection method is extended to measure the chip temperature of various packaged laser modules, such as the DFB laser modules, the FP laser modules, and the EML laser modules. An optimal injection condition is obtained by investigating the dependence of the lasing wavelength on the width and period of the injection pulse in a relatively wide temperature range. The small-signal frequency responses and large-signal performances of packaged laser modules at different chip temperature are measured. The adiabatic small-signal modulation characteristics of packaged LD are first extracted. In the large-signal measurement, the effects of chip temperature, bias current and driving signal on the performances of the laser modules are discussed. It has been found that the large-signal performances of the EML modules depend on the different red-shift speeds of the DFB and EAM sections as chip temperature varying, and the optimal characteristics may be achieved at higher temperature.  相似文献   
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