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181.
182.
Sunil Bharati Richard L. Patience Steve R. Larter Guy Standen Iain J. F. Poplett 《Organic Geochemistry》1995,23(11-12)
The significance and validity of integrating data obtained from a variety of analytical techniques to understand, elucidate and model kerogen's complex chemical structure is reported here using degradative (open and closed system pyrolysis, chemical oxidation), non-degradative (13C CP/MAS NMR) and optical (incident white light and blue light) methods. Seven Cambrian Alum Shale samples, ranging in maturity from immature to post-mature with respect to petroleum generation, were studied and were chosen for their simple geological history, uniform organic matter type and high organic carbon content. The Alum Shale kerogens, which primarily consist of algal organic matter, liberate low molecular weight gaseous and aromatic compounds on pyrolysis and give mostly branched dicarboxylic acids on chemical oxidation. 13C NMR spectroscopy shows that the Alum Shale kerogens are anomalously rich in oxygen-bearing functional groups (such as C = O, ArCO, CHO, CHxO), most of which apparently remain intact within the kerogen macro-molecule (KMM) through the diagenetic and catagenetic stages. Fragments released by different degradative techniques are quantified and the aromaticity (fa), O/C and relative proportions of various carbon types estimated by 13C NMR. A synthesis of these data has allowed us to better understand the chemistry of the Alum Shale kerogen. 相似文献
183.
Walter K?hnlein 《Journal of Geodesy》1963,37(2):201-209
This paper presents a way for computing geodesic polygons on real surfaces of revolution with partly continuous curvature
and gives an application to coordinate transformations in geodesic coordinate systems. The specific formulas for an ellipsoid
of revolution are briefly mentioned. 相似文献
184.
185.
Strontium isotope ratios and rare-earth element abundances have been measured in acid, intermediate and basic rocks from three late to postglacial volcanic complexes, and several other postglacial basalts in Iceland. Late and postglacial basalts in Iceland have been generated from a source region which is essentially homogeneous with respect to87Sr/86Sr. The mean87Sr/86Sr ratio for the basalts analysed is 0.70328 and the range is from 0.70317 ± 6to0.70334 ± 5 (2σ).Acid rocks from the Kerlinganfjöll and Namafjall volcanic complexes have87Sr/86Sr ratios which are indistinguishable from analysed basalts from the same complexes. However, intermediate and acid rocks from the Torfajökull complex have significantly higher87Sr/86Sr ratios and could not have been derived by fractional crystallization from basaltic magmas similar to those found in the same complex. These latter rocks have most probably been produced by remelting of Tertiary gabbroic rocks in Layer 3. Most of the basalts analysed have higher total rare-earth element abundances than typical dredged ocean-ridge tholeiites, and show less light rare-earth depletion. Intermediate and acid compositions show overall higher abundances and light rare-earth enrichments. The measured rare-earth abundances are compared with abundances generated by differential partial melting of various model source regions.It is shown that both the tholeiitic and alkali basalt compositions could be generated from the same source material by different degrees of partial melting. Variable partial melting of gabbroic material may account for the rare-earth element abundances of both the rhyolitic rocks (small degrees of melting) and the intermediate rocks (more extensive melting). 相似文献
186.
LlPingxiang WANGZhijun 《地球空间信息科学学报》2003,6(2):31-34
On the basis of a thorough understanding of the physical characteristics of remote sensing image,this paper employs the theories of wavelet transform and signal sampling to develop a new image fusion algorithm.The algorithm has been successfully applied to the image fusion of SPOT PAN and TM of Guangdong province, China The experimental results show that a perfect image fusion can be built up by using the image analytical solution and reconstruction in the image frequency domain based on the physical characteristics of the image formation.The method has demonstrated that the results of the image fusion do not change spectral characteristics of the original image. 相似文献
187.
188.
YU Xuexiang associate professor Ph.D Department of Resource Environment Engineering Anhui University of Science Technology Huainan China. XU Shaoquan GAO Wei LU Weicai 《地球空间信息科学学报》2003,6(4):51-56
A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct. 相似文献
189.
WEIWenzhan ZHONGYexun PENGYueying ZHENGHongbo 《地球空间信息科学学报》2003,6(3):62-65
190.
SAR image classification based on its texture features 总被引:2,自引:2,他引:0
LIPingxiang FANGShenghui 《地球空间信息科学学报》2003,6(3):16-19
SAR images not only have the characteristics of all-ay, all-eather, but also provide object infor-mation which is different from visible and infrared sensors. However, SAR images have some faults, such as more speckles and fewer bands. The au-thors conducted the experiments of texture statistics analysis on SAR im-age features in order to improve the accuracy of SAR image interpretation.It is found that the texture analysis is an effective method for improving the accuracy of the SAR image interpreta-tion. 相似文献