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排序方式: 共有544条查询结果,搜索用时 15 毫秒
1.
LIN Chang ZHANG Xiu-Lian 《理论物理通讯》2005,44(2):247-251
The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation. 相似文献
2.
讨论了尘埃粒子解的时空结构及其性质,导出了尘埃粒子的内空间的离散结构.证明了尘埃粒子内部的物质球是一个无坐标的平直球,因而具有最小的体积和整体的关联性.导出了在尘埃粒子的内外时空中的径向测地线并说明其连续性.阐述了由这个解所揭示的物质、引力与时空之间的内在联系.
关键词:
尘埃粒子
离散时空
测地线 相似文献
3.
Yang Ruike Wu Zhensen You Jinguang 《International Journal of Infrared and Millimeter Waves》2003,24(8):1383-1392
The influence of sand and dust storms on modern MMW and satellite communication systems reliability have been paid more attention to. The attenuations induced by sand and dust storms are estimated by means of Mie-theory and Rayleigh approximation, in the case of the tenuous distribution of particles. With the particle density increasing, however, these method become inadequate, the multiple scattering effects then become dominant for attenuation estimation. The attenuations considering multiple scattering effects are estimated by Monte-Carlo and four fluxes method at horizontal paths. At slant paths, based on multi-layer media model, the attenuations considering multiple scattering effects are calculated by layered Monte-Carlo method at 100, 37, 24, and 14GHz. It is shown that the multiple scattering effects should be considered at the attenuation prediction in the sand and dust storm, which the visibility is about 0.5km and smaller than 0.5km and frequency is about 20GHz. Above 30GHz, the multiple scattering effects due to sand and dust particles should be considered, as visibility is about 1km and smaller than 1km at slant paths. 相似文献
4.
We exhibit timelike geodesic paths for a metric, introduced by Bonnor [11] and considered also by Steadman [13], and show that coordinate time runs backward along a portion of these geodesics. 相似文献
5.
Charge density fluctuation of low frequency in a dusty plasma 总被引:2,自引:0,他引:2
The charge density fluctuation of low frequency in a dusty plasma, which is derived from the longitudinal dielectric permittivity
of the dusty plasma, has been studied by kinetic theory. The results show that theP value, which describes the relative charge density on the dust in the plasma, and the charging frequency of a dust particle
Ω
c
, which describes the ratio of charge changing of the dust particles, determine the character of the charge density fluctuation
of low frequency. For a dusty plasma ofP≪1, when the charging frequency Ω
c
, is much smaller than the dusty plasma frequency ωd, there is a strong charge density fluctuation which is of character of dust acoustic eigenwave. For a dusty plasma ofP≫1, when the frequency Ω
c
, is much larger than ω
d
there are weaker fluctuations with a wide spectrum. The results have been applied to the ionosphere and the range of radius
and density of dust particles is found, where a strong charge density fluctuation of low frequency should exist. 相似文献
6.
Analysis of a part of the meteorite which fell at Dergaon (India) on March 2, 16.40 local time (2001) is presented with the
help of FTIR, absorption and atomic spectra. The FTIR spectrum exhibits prominent absorption bands in the region 800–1100
cm−1, originating from the valence vibration of SiO4, a basic component of the silicate lattice. 相似文献
7.
A new element tracer technique has firstly been established to estimate the contributions of mineral aerosols from both inside and outside Beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside Beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in Beijing, of which mineral aerosol accounted for 32%―67% of total suspended particles (TSP), 10%―70% of fine particles (PM2.5), and as high as 74% and 90% of TSP and PM2.5, respectively, in dust storm. The sources from outside Beijing contributed 62% (38%―86%) of the total mineral aerosols in TSP, 69% (52%―90%) in PM10, and 76% (59%―93%) in PM2.5 in spring, and 69% (52%―83%), 79% (52%―93%), and 45% (7%―79%) in TSP, PM10, and PM2.5, respectively, in winter, while only ~20% in summer and autumn. The sources from outside Beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in Beijing. The contributions from outside Beijing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors. 相似文献
8.
9.
锂辉石—石灰石烧结中煤粉代替重油作燃料的研究和实践 总被引:1,自引:0,他引:1
目前世界锂工业原料以锂辉石为主。我国锂辉石储量居世界首位,主要分布于新疆、四川、湖南等地,其中又以四川的储量占全国第一。锂的主要基础化合物LiOHH2O系用锂辉石-石灰石烧结法而得,烧结燃料是影响LiOHH2O产品价格的重要因素之一。过去国内外均采用... 相似文献
10.
炉前煤低温干馏工艺中的挥发分除尘 总被引:3,自引:1,他引:3
为了寻求优化的炉前煤低温干馏工艺中的挥发分除尘方案,在使用400目金属滤网对间歇式粉煤固体热载体热解装置挥发分除尘研究的基础上,将颗粒床过滤器用于该过程的除尘研究。热态除尘实验表明,颗粒床的使用有效地降低了滤网的过滤负荷。选用2mm石英砂和φ5mm×2mm瓷环作为滤料,通过对比实验发现,两种滤料除尘效率均在90%以上;随着过滤操作的进行,由于颗粒床内粉尘的沉积使其过滤效率有所提高,而对气、液收率的影响很小。结果表明,颗粒床与滤网结合可作为粉煤炉前低温干馏工艺中可供选择的挥发分除尘方案。 相似文献