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261.
The high-temperature and pressure experimental data of garnet, sillimantite and biotite-bearing potash feldspar gneiss (SGBG, natural block rock) has shown that metamorphic reactions between garnet and melt, and mineral assemblage evolutional features are not only controlled byP-T condition, but also genetically correlate with dehydration-melting of biotite and partial melting of felsic minerals. Combining experimental data with theoretical analyses, the genetic mechanism of metamorphic reaction and its dynamic significance have been demonstrated in the process of metamorphic evolution of khondalite series on the border of Jin (Shanxi Province)-Inner Mongolia. Project supported by the Youth Geologist Foundation of Ministry of Geology and Mineral Resources of China, the Post-docter Foundation and the National Natural Science Foundation of China (Grant No. 49572138).  相似文献   
262.
曙103块古潜山碳酸盐岩测井储层评价   总被引:1,自引:0,他引:1  
李瑞 《矿物岩石》1998,18(4):43-49
由于古潜山碳酸盐岩储层普遍存在非均质性,孔、缝的定性、定量识别至关重要。本文通过测井资料,运用多矿物模型、Φ-Sw-K,F-Φ-m交会图、裂缝孔隙度计算、ISODATA模糊聚类识别裂缝类型等处理工作,对区内6口井进行了测井储层综合评价,取得了较好的效果。  相似文献   
263.
洪水演算理论与计算方法的若干进展与评论   总被引:2,自引:0,他引:2       下载免费PDF全文
从洪水波运动的小扰动分析、水力学洪水演算方法及新技术在洪水演算中的应用等方面,总结了近20年来国内外洪水演算理论与计算方法研究的若干进展,并作了简要的评论.  相似文献   
264.
Dynamics of the three-dimensional structure of the wind-driven Deacon cell in a β-plane channel are discussed in a homogeneous model in the presence of a sufficiently high ridge. The emphasis is on the water mass balance: how the northward surface Ekman drift is returned. It is demonstrated that a sufficiently high ridge can break up the geostrophic constraint and a net geostrophic volume flux across the open latitude band is allowed. It is found that: (1) the Deacon cell is a fundamentally three-dimensional structure, (2) wind forcing can drive an inter-basin water mass exchange in the Southern Ocean, and (3) zonal through-channel transport in the circumpolar ocean varies at different longitudes.  相似文献   
265.
 At the northern part of the Portuguese mainland, the upflow zone of several hot and cold HCO3/Na/CO2-rich mineral waters is mainly associated with important NNE–SSW faults. Several geochemical studies have been carried out on thermal and non-thermal hydromineral manifestations that occur along or near these long tectonic alignments. The slight chemical differences that exist between these meteoric hot and cold HCO3/Na/CO2-rich mineral waters seem to be mainly caused by CO2. δ13C(TIDC) values observed in these groundwaters range between –6.00 and –1.00‰ versus V-PDB (V denotes Vienna, the site of the International Atomic Energy Agency; PDB originates from the CaCO3 of the rostrum of a Cretaceous belemnite, Belemnitella americana, collected in the Peedee formation of South Carolina, USA) indicating a deep-seated (mantle) origin for most of the CO2. Nevertheless, in the case of the heavier δ13C(TIDC) values, the contribution of metamorphic CO2 or the dissolution of carbonate rock levels at depth cannot be excluded. Concerning the hot waters, the lack of a positive 18O-shift should be attributed to water-rock interaction in a low temperature environment, rather than to the isotopic influence of CO2 on the δ18O-value of the waters. Received: 9 August 1999 · Accepted: 8 March 2000  相似文献   
266.
The soil freeze–thaw controls the hydrological and carbon cycling and thus affects water and energy exchanges at land surface. This article reported a newly developed algorithm for distinguishing the freeze/thaw status of surface soil. The algorithm was based on information from Advanced Microwave Scanning Radiometer Enhanced (AMSR‐E) which records brightness temperature (Tb) in the afternoon and after midnight. The criteria and discriminant functions were obtained from both radiometer observations and model simulations. First of all, the microwave radiation from freeze–thaw soil was examined by carrying out experimental measurements at 18·7 and 36·5 GHz using a Truck‐mounted Multi‐frequency Microwave Radiometer (TMMR) in the Heihe River of China. The experimental results showed that the soil moisture is a key component that differentiates the microwave radiation behaviours during the freeze–thaw process, and the differences in soil temperature and emissivity between frozen and thawed soils were found to be the most important criteria. Secondly, a combined model was developed to consider the impacts of complex ground surface conditions on the discrimination. The model simulations quite followed the trend of in situ observations with an overall relation coefficient (R) of approximately 0·88. Finally, the ratio of Tb18·7H (horizontally polarized Tb at 18·7 GHz) to Tb36·5V was considered primarily as the quasi‐emissivity, which is more reasonable and explicit in measuring the microwave radiation changes in soil freezing and thawing than the spectral gradient. By combining Tb36·5V to indicate the soil temperature variety, a Fisher linear discrimination analysis was used to establish the discriminant functions. After being corrected by TMMR measurements, the new discriminant algorithm had an overall accuracy of 86% when validated by 4‐cm soil temperature. The multi‐year discriminant results also provided a good agreement with the classification map of frozen ground in China. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
267.
The Pleistocene (Eemian) outcrops of Lagoinhas and Prainha, located at Santa Maria Island (Azores), were investigated and their fossil mollusc content reported. These studies revealed that the last glaciation affected two groups of molluscs: the ‘warm‐guest’ gastropods with West African or Caribbean affinities (e.g. Conus spp., Cantharus variegatus, Bulla amygdala, Trachypollia nodulosa) and shallow bivalve species mainly associated with sandy habitats (Ensis minor, Lucinella divaricata, and probably Laevicardium crassum). In this paper we focus on this group of bivalves, which has since locally disappeared from the Azores. We relate the local disappearance of these bivalves in the Azores with the lack of sand in the shelf. The specific characteristics of the Santa Maria shelf combined with the sea‐level drop during the Weichselian prevented deposition of the lowstand deposits and permitted erosion of the previous ones, leaving the shelf without a sediment cover. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
268.
Application of Astronomic Time-latitude Residuals in Earthquake Prediction   总被引:1,自引:0,他引:1  
After the earthquake (Ms = 6.1) occurred in Luquan county of Yunnan province on April 18, 1985, the relationship between major earthquakes and astronomical time-latitude residuals (ATLR) of a photoelectric astrolabe in Yunnan Observatory was analyzed. ATLR are the rest after deducting the effects of Earth’s whole motion from the observations of time and latitude. It was found that there appeared the anomalies of the ATLR before earthquakes which happened in and around Yunnan, a seismic active region. The reason of the anomalies is possibly from change of the plumb line due to the motion of the groundmass before earthquakes. Afterwards, using studies of the anomalous characters and laws of ATLR, we tried to provide the warning information prior to the occurrence of a few major earthquakes in the region. The significant synchronous anomalies of ATLR of the observatory appeared before the earthquake of magnitude 6.2 in Dayao county of Yunnan province, on July 21, 2003. It has been again verified that the anomalies possibly provide the prediction information for strong earthquakes around the observatory.  相似文献   
269.
Research on photosynthetic cnidarians has been mainly focused on the symbiosis established between the cnidarian host and its dinoflagellates endosymbionts from genus Symbiodinium. Despite the potential of imaging techniques for assessing the spatial distribution of key parameters of cnidarian photobiology, such as photochemical activity, chlorophyll a content or green fluorescent proteins (GFPs), to our best knowledge, no study has ever attempted to simultaneous map these three features. In this study, we developed a modified imaging pulse amplitude fluorometer by applying excitation light of different wavelengths and selectively detecting short spectral bands through bandpass filters. The imaging system was used to sequentially excite and quantify chlorophyll variable fluorescence (maximum quantum yield of photosystem II, Fv/Fm), Chl a content (normalized difference vegetation index) and relative content of GFPs. The spatial distribution of these photophysiological parameters was mapped both horizontally, across the surface of the soft corals Sarcophyton cf. glaucum and Sinularia flexibilis and the zoanthid Protopalythoa sp., and vertically, throughout a vertical section of S. cf. glaucum. Results showed bleached areas within each individual coral colony and registered photophysiological changes with S. cf. glaucum tissue depth. Analysis of Protopalythoa sp. polyps’ expansion revealed differential surface patterns of NDVI and GFP concentration, and a negative relation between these latter parameters within each polyp. This novel non‐invasive approach allowed a high‐resolution characterization of the spatial relationship between these key parameters through the analysis of image information on a pixel‐by‐pixel basis, which has great potential for investigating the physiological state of symbiotic associations.  相似文献   
270.
From November 24 to 26, 2014, a red tide event occurred in the offshore water off the Hailing Island located at the western Guangdong coast. The red tide appeared as pink strips distributed within 3 km in the offshore water and extended for about 10 km along the shoreline. During the flood tide, the pink seawater rushed to the beach with breaking waves, forming foam strips on the beach. Guangdong Province Key Laboratory for Coastal Ocean Variation and Disaster Prediction Technologies, Guangdong Ocean University, emergently responded to the event and organized three-dimensional observations from the air, onboard and on beach. The preliminary analyses of the cruise data and water samples indicate that the event was induced by nontoxic Noctiluca scintillans, of which the concentration reaches as high as 4 200 cells/L near the surface and 2 600 cells/L at the bottom.  相似文献   
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