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71.
In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strains on the basis of morphological and molecular data. The cellular dimensions of the Chinese Wenling strain (LAMB090508) and Korean strain (PDKS0206) were similar and the cells of both strains were of asymmetric and elongated shape. The posterior end of most cells was rounded. Megacytic zones of aged cells were broader with dense tiny knobs. The roundish nucleus was located in the posterior part of the cell. A few irregular shaped chloroplasts were distributed within the cell. The nucleotide similarity of the two strains, determined from the 5.8S rDNA-ITS sequences, was 99.83%. The comparative results of morphology and molecular analysis suggest that both strains isolated from China and Korea were the identical species, Prorocentrum donghaiense Lu. 相似文献
72.
Deng Zu-Gan Zhou You-Yuan Liu Yong-Zhen Dai He-Jun 《Astrophysics and Space Science》1986,126(2):301-312
In former works (Zhouet al., 1983, 1985), a quantitative method have been developed to take the selection effects in the identification of emission lines of quasars into account. It was proved that these selection effects may be the cause of the unevenness in the redshift distribution of quasars. The present work is a continuation and development of former works. We use results given by the surveys with same limit-apparent magnitude and choose the quasars whose absolute magnitudes are within a specific range as the analysing samples. Using the method given in the former papers we may find out the evolutionary parameter in an evolutionary law with form of (1+z)
y
from the best fitting between the calculative and observational redshift distribution. The result of analysis shows that the evolutionary law of quasars selected by slitless technique isp =p
0(1 + z)6.5 ± 1 up toz=2.8. This result coincides with and generalizes the earlier result given by other authors. 相似文献
73.
74.
ON SOME KEY SEDIMENTATION PROBLEMS OF THREE GORGES PROJECT (TGP) 总被引:1,自引:0,他引:1
Lin Bingnan Dou Guoren Xie Jianheng Dai Dingzhong Chen Jisheng Tang Richang Zhang Ren 《国际泥沙研究》1989,(1)
I. INTRODUCTIONThe Three Gorges Project (TGP) being planned is to be located on the Yangtze River at Sandouplug, 44 km upstream of Yichang (Fig. l). A scheme studied in the feasibility stage has the crest ofthe dam placed at 185 m with a maximums height o… 相似文献
76.
77.
78.
40Ar/39Ar plateau ages of biotite, plagioclase, K-feldspar and hornblende from the Biluoxueshan and Lincang plutons in the three-river area of Yunnan and the Quxu pluton in the Gandise belt of Xizang indicate that the three plutons were emplaced at 420, 234 and 43.4 Ma, respectively. Based on the study of closure temperatures and thermal histories, it is shown that the Lincang and Biluoxueshan plutons experienced the same thermodynamic event during 85–90 Ma, temporally representing the collision between the Sundaland and Eurasian plates, and that the Quxu pluton was uplifted at a much faster rate during 40–44 Ma(2.6 mm/a), marking the collision between the Indian and Eurasian plates. 相似文献
79.
Common‐conversion‐point binning associated with converted‐wave (C‐wave) processing complicates the task of parameter estimation, especially in anisotropic media. To overcome this problem, we derive new expressions for converted‐wave prestack time migration (PSTM) in anisotropic media and illustrate their applications using both 2D and 3D data examples. The converted‐wave kinematic response in inhomogeneous media with vertical transverse isotropy is separated into two parts: the response in horizontally layered vertical transverse isotrophy media and the response from a point‐scatterer. The former controls the stacking process and the latter controls the process of PSTM. The C‐wave traveltime in horizontally layered vertical transverse isotrophy media is determined by four parameters: the C‐wave stacking velocity VC2, the vertical and effective velocity ratios γ0 and γeff, and the C‐wave anisotropic parameter χeff. These four parameters are referred to as the C‐wave stacking velocity model. In contrast, the C‐wave diffraction time from a point‐scatterer is determined by five parameters: γ0, VP2, VS2, ηeff and ζeff, where ηeff and ζeff are, respectively, the P‐ and S‐wave anisotropic parameters, and VP2 and VS2 are the corresponding stacking velocities. VP2, VS2, ηeff and ζeff are referred to as the C‐wave PSTM velocity model. There is a one‐to‐one analytical link between the stacking velocity model and the PSTM velocity model. There is also a simple analytical link between the C‐wave stacking velocities VC2 and the migration velocity VCmig, which is in turn linked to VP2 and VS2. Based on the above, we have developed an interactive processing scheme to build the stacking and PSTM velocity models and to perform 2D and 3D C‐wave anisotropic PSTM. Real data applications show that the PSTM scheme substantially improves the quality of C‐wave imaging compared with the dip‐moveout scheme, and these improvements have been confirmed by drilling. 相似文献
80.
贺兰山群变质杂岩主期变质作用的温压环境研究 总被引:1,自引:0,他引:1
分布于贺兰山脉北部的贺兰山群变质杂岩的主期变质作用达角闪麻粒岩相,其矿物组合特征与低压相系麻粒岩相似、利用共生矿物组合和矿物对的温度计、压力计估算主期变质温度740—764(?),压力460—501MPa。温度压力条件与低压相系的地热梯度线较接近,变质作用强度具面型分布的特征,与东部密云、冀东等地的麻粒岩相区相似,但变质压力明显低,压力类型也不同,应属不同构造背景下的变质产物。 相似文献