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191.
提出川滇地洼系“四层楼”铜矿床序列的形成与陆壳演化的成生联系,是与本区陆壳由前地槽—地槽—地台—地洼演化各阶段与之相匹配的成矿作用的产物.与此同时,并总结了本区“四层楼”铜矿床序列的成矿作用具有明显的继承性、新生性、旋回性及层控性四大特点和多因复成矿床的成矿模式.  相似文献   
192.
It has become clear in recent years that relativistic beaming is a good explanation for the BL Lac phenomenon. Of studies based on the relativistic beaming model of BL Lac objects, we note that the orientation of jet's axis to the line-of-sight is very small and, therefore, the observed flux emitted from a rapidly moving source is orders of magnitude higher than the flux in its rest-frame:F obs = 3 + F intr, where is the bulk relativistic Doppler factor. Then the observed apparent magnitudem v must be corrected for this effect. For our 39 samples, the corrected apparent magnitudem v corr and logZ have a good correlation.  相似文献   
193.
鄂尔多斯地块构造演化的古地磁学研究   总被引:15,自引:0,他引:15       下载免费PDF全文
鄂尔多斯地块与中朝地台其它地区相同时代地层的古地磁结果基本一致表明:晚二叠世以来,中朝地台经历了从低纬度(19°左右)向中纬度的北移过程,并伴有50°左右的逆时针旋转;晚二叠世—中三叠世地台北移10°(1000km)左右,而方位基本未变;中三叠世—中侏罗世主要发生50°左右的逆时针旋转,而北向位移不明显,这一旋转可能与杨子地台和中朝地台碰撞拼合有关,或者说是印支运动在该地区的反应,中侏罗世—早白垩世地块已基本和现代位置一致  相似文献   
194.
We found that the structure of the Universe can be characterized by a set of actions s . This means that some discontinuous phenomena in the Universe can be considered as large-scale quantum effects. The behaviour of matter on a typical scale is determined by the behaviour of matter on other scales through the interactions.  相似文献   
195.
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   
196.
我国著名的水文地理学家、中国科学院地理研究所研究员郭敬辉同志于1985年4月5日溘然长逝。他的逝世是我国地理学界和水文学界的一大损失。我们怀着十分悲痛的心情对他表示沉重悼念。  相似文献   
197.
The data such as the H-spectrum-spectroheliographic (SSHG) observations, the H-chromospheric observations, etc., of a flare loop prominence which occurred on the western solar limb on 1981 April 27 have been obtained at Yunnan Observatory. The distribution of the internal motions and the macroscopical motion of the flare loop prominence with time and space in the course of its eruption and ascension is derived from the comprehensive analysis of the data. The possible physical pictures and the instability of the motions of the loop are inferred and discussed.  相似文献   
198.
In this paper, using two methods: LCN'S (Lyapunov characteristic numbers) method and slice cutting method, we study numerically two mappings with odd dimension: $$T_1 :\left\{ {\begin{array}{*{20}c} {x_{n + 1} = x_n + z_n ,} \\ {y_{n + 1} = y_n + x_{n + 1} , (\bmod 2\pi )} \\ {z_{n + 1} = z_n + A\sin y_{n + 1} ,} \\ \end{array} } \right. T_2 :\left\{ {\begin{array}{*{20}c} {x_{n + 1} = x_n + y_n + B \sin z_n ,} \\ {y_{n + 1} = y_n + A \sin x_{n + 1} , (\bmod 2\pi ),} \\ {z_{n + 1} = z_n + B \sin y_{n + 1} ,} \\ \end{array} } \right.$$ whereA, B are parameters. For the mappingT 1 the whole region is stochastic; however, we find two-dimensional invariant manifolds for the mappingT 2.  相似文献   
199.
We present a detailed, new time scale for an orogenic cycle (oceanic accretion–subduction–collision) that provides significant insights into Paleozoic continental growth processes in the southeastern segment of the long-lived Central Asian Orogenic Belt (CAOB). The most prominent tectonic feature in Inner Mongolia is the association of paired orogens. A southern orogen forms a typical arc-trench complex, in which a supra-subduction zone ophiolite records successive phases during its life cycle: birth (ca. 497–477 Ma), when the ocean floor of the ophiolite was formed; (2) youth (ca. 473–470 Ma), characterized by mantle wedge magmatism; (3) shortly after maturity (ca. 461–450 Ma), high-Mg adakite and adakite were produced by slab melting and subsequent interaction of the melt with the mantle wedge; (4) death, caused by subduction of a ridge crest (ca. 451–434 Ma) and by ridge collision with the ophiolite (ca. 428–423 Ma). The evolution of the magmatic arc exhibits three major coherent phases: arc volcanism (ca. 488–444 Ma); adakite plutonism (ca. 448–438 Ma) and collision (ca. 419–415 Ma) of the arc with a passive continental margin. The northern orogen, a product of ridge-trench interaction, evolved progressively from coeval generation of near-trench plutons (ca. 498–461 Ma) and juvenile arc crust (ca. 484–469 Ma), to ridge subduction (ca. 440–434 Ma), microcontinent accretion (ca. 430–420 Ma), and finally to forearc formation. The paired orogens followed a consistent progression from ocean floor subduction/arc formation (ca. 500–438 Ma), ridge subduction (ca. 451–434 Ma) to microcontinent accretion/collision (ca. 430–415 Ma); ridge subduction records the turning point that transformed oceanic lithosphere into continental crust. The recognition of this orogenic cycle followed by Permian–early Triassic terminal collision of the CAOB provides compelling evidence for episodic continental growth.  相似文献   
200.
Chemical structure of Jurassic vitrinites isolated from the coals in basins in NW China have been checked using solid state 13C NMR and flash pyrolysis-GC/MS. Study shows some Jurassic collodetrinites are rich in aliphatic products in pyrolysates, consisting with the high amount of methylene carbon in 13C NMR spectra. In contrast, pyrolysates of Jurassic collotelinites are rich in phenols and alkylbenzenes. Also one Pennsylvanian and one Permian vitrinite selected from the Ordos basin, NW China have been checked for comparison. The proportion of aliphatics is low in pyrolysates, and aliphatic carbon peak in 13C NMR spectrum of Permian vitrinite is mostly composed of gas-prone carbons compared with collodetrinites in those Jurassic basins. But both pyrolysis and 13C NMR data shows the Pennsylvanian vitrinite is not only gas-prone but also oil-prone. Relatively high proportion of long chain aliphatic structure of some Jurassic vitrinite in Junggar, Turpan-Hami basins may be due to the contribution of liptodetrinites, which may be included during the formation of vitrinites. And it seems that suberinite is the most possible precursor of long chain aliphatics in the structure of Jurassic collodetrinite.  相似文献   
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