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81.
We have made a statistical analysis on the subpulse width, the mean pulse width and the rate of change of polarization angle in pulsars. We obtained a number of empirical relations showing how these radio emission characteristics are related to the magnetic inclination and discussed the physical implications of the relations. 相似文献
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83.
U-Pb zircon ages for the Luzhenguan Complex in northern part of the eastern Dabie orogen 总被引:4,自引:0,他引:4
Wolfgang Siebe 《中国科学D辑(英文版)》2005,48(9):1357-1367
The Dabie Mountain is the collisional orogenic belt between the North China Block and the Yangtze Block. As the eastern segment of the central-China orogenic belt, its tectonic framework is corresponding to the Qinling orogenic belt as a whole[1]. The NHB in northern part of Dabie Orogen is regarded as the joint belt between the Yangtze Block and the North China Block, and roughly corresponds to the north Qinling belt of the Qinling orogenic belt, which separated the Tongbai-Dabie hig… 相似文献
84.
The Loess Plateau in Northwestern China, with 60 million inhabitants, is strongly endangered by heavy erosion quickly decreasing soil fertility and yield of crops, causing also severe problems in the main river of the area, uplifting its bed by strong sedimentation. This situation is mainly due to improper land use, cutting woods, ploughing up grasslands which are the consequence of the decreasing yield of former plough lands. This vicious cycle may only be disrupted by a proper land management based on the newest results of scientific research, on up to date data bases as well as on traditional methods. The land melioration methods must primarily aim at a prevention of further erosion and at an increase of infiltration by different methods, but all means of a proper country planning and development should be harmonised in order of halting of further deterioration of the area. 相似文献
85.
We report on the 3-colour photoelectric monitoring of the shell star in Perseus, discovered in 1978, [1]. On the night of 1983 Feb 4–5, this star still showed obvious light variations, though the amplitude was less than in 1979. On the next night, the light variation was close to the observing error. We surmise that the shell activity is now at a stable phase for a few years. 相似文献
86.
Xing Chen Wangsheng Chu Dongliang Chen Zhonghua Wu A. Marcelli Ziyu Wu 《Chemical Geology》2009,268(1-2):74-80
The local and geometrical structure around gold (III) e.g., Au3+ ions in aqueous solution with different OH−/Cl− molar ratios, has been investigated by X-ray absorption spectroscopy (XAS). X-ray absorption near-edge structure (XANES) spectra of [AuCln(OH)4−n]− solutions have been calculated and the multiple-scattering spectral features have been attributed to Cl d-states, axial water molecules and the replacement of Cl− ligands by OH− ligands. A square–planar geometry for [AuCln(OH)4−n]− with two axial water molecules has been identified. Moreover, a spectral correlation between XANES features and the type of planar atoms has been identified. By extended X-ray absorption fine structure spectra (EXAFS), the planar Au bond distances in the solutions have also been determined, e.g., 2.28 Å for Au–Cl and 1.98 Å for Au–O, respectively. The same EXAFS analysis provides evidence that the peak at about 4.0 Å in solutions with the lowest OH−/Cl− molar ratio arises from collinear Cl–Au–Cl multiple-scattering contributions. For the first time, a complete detailed reconstruction of the hydration structure of an Au ion at different pH values has been achieved. 相似文献
87.
88.
Xiao Yang Yuan Zhengxin Lin Jia Ran Jinyu Dai Beibing Chu Jian Liu Hanlong 《Acta Geotechnica》2019,14(6):2123-2131
Acta Geotechnica - Few studies have focused on the influence of particle shape on the mechanical properties of cemented sand. To address this lack of information, this study investigated the... 相似文献
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90.
Acta Geotechnica - The spatial variation of the physical–mechanical properties of rock or rock-like materials is an intrinsic characteristic of the materials induced by multiscale material... 相似文献