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181.
Summary. The contributions from the oceanic and ionospheric dynamos, Lo and LI respectively, to the geomagnetic lunar daily variation, L , at Alibag, a coastal station in the Indian equatorial region, are calculated from the L harmonics derived from a 41–yr long series of observations. The analysis in the calendar months shows a steady and significant ocean dynamo contribution in the vertical component, Z, in all the months except April. Examination, by an analysis of the data year by year, of the association of Lo and LI with varying solar and magnetic activities reveals, surprisingly, a stable correlation between the magnetic activity index A P and the oceanic part in the horizontal and vertical components but not in declination, which probably indicates the influence of induced currents, along the latitudes, on L o . 相似文献
182.
In this paper we compute the rate of solar EUV heating in the upper atmosphere by photo-dissociation and photo-ionization, taking care to include properly the effects of oblique incidence of solar flux, sphericity of the atmosphere and ellipticity of the Earth's orbit. The time and latitudinal variations of the computed heat function are revealed by numerical Fourier analysis of the heat function into harmonics of the yearly cycle. It is shown that EUV absorption contains a ‘latitude independent’ semi-annual component of heating with the ‘proper phase’ to account for the semi-annual density variations. Further, the annual component of the heat function predicts the existence of ‘summer polar’ density increases in the northern and southern hemispheres. 相似文献
183.
184.
185.
Summary All of the barium and marginal barium stars in the 1972 MacConnell, Frey, and Upgren (1972: MFU) list of such objects which
are located south of the celestial equator were examined for visual duplicity. Over 200 objects were observed, and a total
of six possible candidates for wide pair visual binaries were found. Of these, four are most likely optical in nature. These
data suggest that the incidence of wide binaries among barium stars is of the order of 1%. 相似文献
186.
187.
Dust sediments collected from 1995 to 1998 in Beijing, Dunhuang, Inner Mongolia, Kashi, the Kunlun Mountains, Lanzhou, Ningxia, the Taklimakan Desert, and Xi‘an, China, were characterized in terms of their physical, chemical, and mineralogical properties. Most aerosols and dust analysed ranged in texture from silty clay to clay loam. Their median particle diameters (Mds) generally ranged between 5 to 63μm,coinciding with those of loess from central China and the finest sand from northwestern China. The dust sediments were characterized by a predominance of SiO2 and Al2O3, followed by K2O. Their SiO2/Al2O3and K2O/SiO2 molar ratios ranged from 5.17 to 8.43 and from 0.009 to 0.0368, respectively. The mass concentration spectrum during a dust storm showed a single peak, rather than the triple peak generally observed under clear sky conditions. The dominant minerals were chlorite, illite, calcite, and dolomite.These physical, chemical, and mineralogical properties were consistent with those of aeolian soils and loess in western and central China. The results suggest that aerosols and fine-gained fractions of dust sediments collected in northern China are mainly composed of soil material transported from the arid and semiarid regions of China and Mongolia by prevailing winds. The rate of deposition and properties of dust falling on eastern China were strongly influenced by meteorological conditions, season, latitude, longitude, and altitude of the sampling sites. 相似文献
188.
Debasish Chakraborty Gautam Kumar Sen Sugata Hazra 《Journal of Earth System Science》2009,118(5):609-617
Texture in high-resolution satellite images requires substantial amendment in the conventional segmentation algorithms. A measure is proposed to compute the Hölder exponent (HE) to assess the roughness or smoothness around each pixel of the image. The localized singularity information is incorporated in computing the HE. An optimum window size is evaluated so that HE reacts to localized singularity. A two-step iterative procedure for clustering the transformed HE image is adapted to identify the range of HE, densely occupied in the kernel and to partition Hölder exponents into a cluster that matches with the range. Hölder exponent values (noise or not associated with the other cluster) are clubbed to a nearest possible cluster using the local maximum likelihood analysis. 相似文献
189.
Tamarix nabkha is one of the most widespread nabkhas,distributing in the arid region of China.Based on the observations outdoors and the simulation experiments in laboratories,analysis in this paper refers to the biological geomorphologic features and growth process of Tamarix nabkhas in the middle and lower reaches of the Hotan River,Xin- jiang.And the results indicate that the ecological type of Tamarix in the study area is a kind of Tugaic soil habitat based on the deep soil of the Populus Diversifolia f... 相似文献
190.
Vishal Chandr Jaunky 《Natural Resources Research》2012,21(2):265-278
The article attempts to test the aluminum consumption–economic growth nexus for 20 rich economies for the period 1970–2009.
Various panel data unit root and cointegration tests are applied. The series are found to be integrated of order one and cointegrated,
especially after controlling for cross-sectional dependence. Moreover, the Blundell–Bond system generalized methods-of-moments
is employed to conduct a panel causality test in a vector error-correction mechanism setting. Unidirectional causality running
from aluminum consumption to real GDP is uncovered in the short-run, while real GDP is found to Granger-cause aluminum consumption
in the long-run. Moreover, a 1% increase in real GDP generates an increase of 0.44% in aluminum consumption in the long-run
for the whole panel. 相似文献