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981.
采用云与地球辐射能量系统(CERES)2003~2007年的CERESSSF Aqua MODIS云资料,选取新疆阿尔泰山、天山和昆仑山三大山区,通过考察云量和云液态水柱含量分析了低层云水资源的多年空间分布和季节变化特征。结果表明,三大山区多年平均的云量年平均区域值在24.4%~27.5%之间,云液态水柱含量在51~56.3g/m2之间。三大山区低层云量和云液态水柱含量有明显的季节变化特征。综合云量和云水柱含量来看,春季是三大山区低层云量资源最丰富的季节,冬季是三大山区低层云中的含水量最丰富的季节。 相似文献
982.
Tai is a family of related languages and dialects, a subgroup of the Tai-Kadai languages, spoken by more than 85 million speakers in southern China and Southeast Asia. This paper uses GIS to map the spatial
distribution of Tai toponyms (Muang, Chiang and Viang) and analyzes their relationship with terrain characteristics. In Tai, Muang means flat “basin”, Chiang means “town”, and Viang provides defense for a Chiang. These Tai toponyms are found at places with a significantly higher compound topographic index (or wetness index) than others. Watershed
basins with more Muang toponyms are characterized by lower elevation, gentler slope, near zero concavity. All of these are consistent with physical
conditions favorable for wet rice agriculture, culture, and commerce. The transnational spatial distribution of these toponyms
and associated terrain characteristics reveal a significant regional pattern that reflects not only the geomorphology of the
places where Tai expanded and settled, but also a common history and culture of naming places influenced by their wet rice
agriculture and associated cultural practices and commerce. 相似文献
983.
考虑半参数平差模型L=Bx+S+Δ,xεRd,S为未知回归参数,为未知Borel函数。本文首先利用自然样条函数法,找到符合条件的非参数自然样条插值函数。其次利用偏残差法并综合最小二乘法,导出了参数和非参数的解算公式,讨论了窗宽参数的选取方法。在本文的最后,将这种估计方法应用到重力场的计算中,说明了利用半参数平差模型估计参数的有效性。 相似文献
984.
985.
向着地球深部进军是未来地质科学研究的战略目标之一,微区则是探寻深部地幔元素迁移和物质循环的关键。分子、原子级矿物的分析研究将在解密深部地幔物理化学条件、物质组成中扮演重要角色。蛇绿岩中豆荚状铬铁矿是微米级矿物的主要载体之一。近年来,随着单晶衍射仪、微区衍射和透射电镜等实验技术的发展和应用,在豆荚状铬铁矿中发现了一系列微米级矿物,为揭示地幔物质组成和演化历史提供重要信息。铬铁矿中发现新矿物的矿床包括中国西藏的罗布莎铬铁矿矿床和希腊中部Othrys矿床。其中,罗布莎铬铁矿矿床中发现包括罗布莎矿、林芝矿、那曲矿、藏布矿、雅鲁矿、曲松矿、自然钛、青松矿、巴登珠矿、志琴矿、经绥矿、康金拉矿及文吉矿在内的13种新矿物;Othrys蛇绿岩的Agios Stefanos矿床发现的新矿物有arsenotu? ekite、eliopoulosite、tsikourasite和grammatikopoulosite。这些新矿物以过渡族元素(Fe、Cr、Ni、Mo、V等)、钛的硅化物、碳化物、镍的磷化物等自然元素及金属化合物为主。它们多以矿物发现地或为地学研究做过卓越贡献的科学家名字命名。微米级矿物的发现拓展... 相似文献
986.
We have analyzed a large sample of FSRQs detected by Fermi LAT. Our main intents are to investigate the relations between bulk Lorentz factor and black hole mass, between bulk Lorentz factor and Eddington ratio. Using archive and calculation, we obtained the distributions of bulk Lorentz factor, black hole mass and Eddington ratio. After excluding redshift effect, there is still significant correlation between bulk Lorentz factor and black hole mass, but not correlation between bulk Lorentz factor and Eddington ratio, which suggest that faster jets have a close relation with more massive black holes, and the Blandford–Znajek (BZ) mechanism may dominate over the Blandford–Payne (BP) mechanism for Fermi FSRQs. 相似文献
987.
Yongjuan Cha Haojing Zhang Xiong Zhang Dingrong Xiong Bijun Li Xia Dong Jin Li 《Astrophysics and Space Science》2014,349(2):895-908
Using γ-ray data (α γ , F γ ) detected by Fermi Large Area Telescope (LAT) and black hole mass which has been compiled from literatures for 116 Fermi blazars, we calculated intrinsic γ-ray luminosity, intrinsic bolometric luminosity, intrinsic Eddington ratio and studied the relationships between all above parameters and redshift, between α γ and L γ . Furthermore, we obtained the histograms of key parameters. Our results are the following: (1) The main reason for the evolutionary sequence of three subclasses (HBLs, LBLs, FSRQs) may be Eddington ratio rather than black hole mass; (2) FSRQs occupy in the earlier, high-luminosity, high Eddington ratio, violent phase of the galactic evolution sequence, while BL Lac objects occur in the low luminosity, low Eddington ratio, late phase of the galactic evolution sequence; (3) These results imply that the evolutionary track of Fermi blazars is FSRQs ? LBLs ? HBLs. 相似文献
988.
FU Jun-ping ZHANG Hao-jingZHANG Xiong XIONG Ding-rongGUO Fei 《Chinese Astronomy and Astrophysics》2014
We have collected the 37 GHz radio data of PKS 1510-089 from 1990 to 2005, and obtained its long-term light curve after making data processing. From the light curve we can find that the activity in PKS 1510-089 is very strong. In this paper, the Period04 method is used for the first time to analyze the light periodicity of PKS 1510-089. The result indicates that its radio emission at 37 GHz has the periods of (1.87±0.13) yr and (0.87±0.07) yr. This result is consistent with the results obtained by Xie et al. in 2004, 2005, 2008, and Wu et al. in 2005 with other methods of data analysis. 相似文献
989.
The European Centre for Medium-Range Weather Forecasts Re-Analysis Interim
(ERA-Interim) meteorology and measurements from the Microwave Limb Sounder,
High Resolution Dynamics Limb Sounder, and Ozone Monitoring Instrument
onboard the Earth Observing System Aura satellite were applied to analyze
the dynamical and chemical features of a cutoff low (COL) event over
northeast China in early July 2007. The results showed the polar
stratospheric origin of an upper-level warm-core cyclone at 100--300 hPa,
associated with a funnel-shaped tropopause intruding into the
mid-troposphere just above the COL center. The impacts of the stratospheric
intrusion on both column ozone and ozone profiles were investigated using
satellite measurements. When the intensity of the COL peaked on 10 July
2007, the total column ozone (TCO) increase reached a maximum (40--70 DU).
This could be dynamically attributed to both the descent of the tropopause
(~75%) and the downward transport of stratospheric ozone across the
tropopause (~25%). Analysis of the tropospheric ozone profiles
provided evidence for irreversible transport/mixing of ozone-rich
stratospheric air across the tropopause near the upper-level front region
ahead of the COL center. This ozone intrusion underwent downstream transport
by the upper tropospheric winds, leading to further increase in TCO by
12--16 DU over broad regions extending from east China toward the northern
Japan Sea via South Korea. Meteorological analysis also showed the
precedence of the stratospheric intrusion ahead of the development of
cyclones in the middle and lower troposphere. 相似文献
990.
In recent years, export value-added tax (VAT) refund rebate and export tax (EVRRET) measures have been adopted for energy-intensive products in China. They are proclaimed to be climate policy, yet there is no explicit and unique carbon cost set on export, and the implicit export carbon tax rates vary dramatically across sectors and over different periods. A method is provided to introduce an explicit and unique carbon cost into the current EVRRET. By setting a comparable carbon cost (US$20/tCO2 and US$30/tCO2) for eight major energy-intensive sectors to which the EVRRET is widely applied, it derives the corresponding ad valorem average rate for each sector. The introduction of a carbon cost into export VAT refund rebate policy would not increase the current export VAT refund rebate rate (except for the chemical sector), but would simply define a ceiling. However, the same introduction into the export tax policy would lead to an overall increase in sectoral export tax rates. In terms of competitiveness and World Trade Organisation concerns, the better option for introducing a carbon cost into Chinese exports would be through reforming export VAT refund rebate policy. 相似文献