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M. Chandra Singh R. A. S. Kushwaha Gaurav Srivastava R. C. Mehrotra 《Journal of the Geological Society of India》2012,79(3):287-294
Some plant remains are described from the Laisong Formation (Barail Group) of Thoubal and Senapati districts of Manipur. The
flora is diverse comprising gymnospermous, monocotyledonous and dicotyledonous forms and indicates tropical to subtropical
climate in the vicinity of the area during the deposition of the host rocks. 相似文献
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Gaurav Shrestha Youhei Uchida Satoru Kuronuma Mutsumi Yamaya Masahiko Katsuragi Shohei Kaneko Naoaki Shibasaki Mayumi Yoshioka 《Hydrogeology Journal》2017,25(5):1437-1450
Development of a ground-source heat pump (GSHP) system with higher efficiency, and evaluation of its operating performance, is essential to expand the growth of GSHP systems in Japan. A closed-loop GSHP system was constructed utilizing a flowing (artesian) well as a ground heat exchanger (GHE). The system was demonstrated for space-heating and space-cooling of a room (area 126.7 m2) in an office building. The average coefficient of performance was found to be 4.5 for space-heating and 8.1 for space-cooling. The maximum heat exchange rate was 70.8 W/m for space-heating and 57.6 W/m for space-cooling. From these results, it was determined that a GSHP system with a flowing well as a GHE can result in higher performance. With this kind of highly efficient system, energy saving and cost reduction can be expected. In order to assess appropriate locations for the installation of similar kinds of GSHP systems in Aizu Basin, a suitability map showing the distribution of groundwater up-flowing areas was prepared based on the results of a regional-scale three-dimensional analytical model. Groundwater up-flowing areas are considered to be suitable because the flowing well can be constructed at these areas. Performance evaluation of the GSHP system utilizing the flowing well, in conjunction with the prepared suitability map for its installation, can assist in the promotion of GSHP systems in Japan. 相似文献
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Vivesh V. KAPUR Kamlesh KUMAR Pranav J. PANDYA Amit K. GHOSH Arindam CHAKRABORTY Anupam SHARMA Gaurav CHAUHAN M. G. THAKKAR 《《地质学报》英文版》2022,96(6):1867-1883
The oldest Asian record of alpheid shrimps, assigned to genus Alpheus, based on snapping claw fingertips from the Miocene Khari Nadi Formation in the Kutch Basin, western India reported herein, extends the fossil record of the family Alpheidae from Asia by ~22 million years. An early Miocene (Aquitanian) age is estimated based on the associated assemblage of calcareous nannofossils, Sphenolithus disbelemnos, Cyclicargolithus floridanus, and Reticulofenestra haqii. The co-occurring microbiota includes bony fish otolith remains, identified as “genus Gobiidarum”, isolated teeth of Dasyatis rays, Sphyrna sharks, and teleosts, ctenoid and placoid scales, ostracods, belonging to the genera Paractinocythereis, Alocopocythere, Ruggieria? Aglaiocypris, Bairdoppilata, and echinoid spines. Taken together, the microfossil assemblage and data from chemical analyses using Energy Dispersive Spectroscopy, X-Ray Diffraction and Wavelength Dispersive X-Ray Fluorescence of host and associated lithologies suggests prevalence of a shallow (neritic) to coastal marine (intertidal) depositional paleoenvironment. 相似文献
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K. H. Navalgund K. Suryanarayana Sarma Piyush Kumar Gaurav G. Nagesh M. Annadurai 《Journal of Astrophysics and Astronomy》2017,38(2):34
AstroSat is India’s first space-based observatory satellite dedicated to astronomy. It has the capability to perform multi-wavelength and simultaneous observations of cosmic bodies in a wide band of wavelengths. This paper briefly summarizes the challenges faced in the configuration of AstroSat spacecraft, accommodation and sizing of its critical subsystems, their realization and testing of payloads and the integrated satellite. 相似文献
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Performance analysis of different predictive models for crop classification across an aridic to ustic area of Indian states 总被引:1,自引:0,他引:1
The purpose of this study is to present comparative performance analysis of different machine learning algorithms for large area crop classification. Ten Indian districts with significant rabi crops viz. wheat, mustard, gram, red lentils (masoor) have been selected for the study. Most popular classical ensemble models – bagging/ARCing, random forest (RF), gradient boosting and Importance Sampled Learning Ensemble (ISLE) with traditional single model (decision tree) have been selected for comparative analysis. To incorporate dependency of large area crop in different variables viz. parent material and soil, phenology, texture, topography, soil moisture, vegetation, climate etc., 35 digital layers are prepared using different satellite data (ALOS DEM, Landsat-8, MODIS NDVI, RISAT-1, Sentinental-1A) and climatic data (precipitation, temperature). In rabi season, field survey about crop type is carried out to prepare training data. Performance is evaluated on the basis of marginal rates, F-measure and Jaccard’s coefficient of community, Classification Success Index and Agreement Coefficients. Score is calculated to rank the algorithm. RF is best performer followed by gradient boosting for crop classification. Other ensemble methods ARCing, bagging and ISLE are in decreasing order of performance. Traditional non-ensemble method decision tree scored higher than ISLE. 相似文献
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Nishant Roy Rajib Sarkar Kripamoy Sarkar Mahesh Kumar Jat Gaurav Fulwaria 《Journal of the Geological Society of India》2018,91(4):449-456
The Ghawar anticline (GA) is the super-giant anticline belonging to a set of giant anticlines called the Rayn anticlines (RA) developed in the Eastern Province (EP), Saudi Arabia. The RA is situated within the Arabian block microplate forming the distant foreland of the Zagros. For the first time, using the ‘Reviewed ISC Earthquake Catalogue’ for the period of 1970-2010, it is demonstrated that the EP crust is seismogenic down to a depth of ~15 km or more and has a typical surface width of ~220 km; this width is ostensibly six-times wider than that of GA. The Saudi Geological Survey (SGS) Earthquake Network Catalogue is utilized to study local seismicity. The GA is locally seismically active such that 826 events have occurred during the period of 2005-2010, with a maximum magnitude of ML 4.24. Magnitude completeness (Mc) analysis, based on the assumption of self-similarity, suggests that all local earthquakes above a cut-off magnitude of ³2.7 have been detected in EP. Certain basic estimates on the average depth of origin of the induced events and histogram plot on the frequency of induced and ambient (natural) seismicity are illustrated. The induced events came almost in equal proportions from the Uthmaniyah-Hawaiyah and Haradh production divisions belonging to the central and southern oil/gas Fields in GA. Poroelastic parameters of the reservoir are reviewed with respect to the induced seismicity. Focal-depth distribution of events along the strike direction of seismic zones follows the ‘En-Nala axis’ in the GA and is used, together with ISC data, to broadly define the seismogenic crust from a 3D-perspective. Seismic activity below both production divisions is supposedly triggered by hydrocarbon fluid-extraction; locally triggered seismicity shows better correlation to mutually opposite reverse faults transgressing the Haradh and Uthmaniyah-Hawaiyah production divisions under the influence of regional compressive stress oriented along N40°E. Results from four composite focal mechanism solutions also support this contention. 相似文献
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The plant fossil records from the Siwalik Group of Arunachal Pradesh, India are far from satisfactory due to remoteness and dense vegetation of the area. We report seven fossil woods of which three belong to the Middle Siwalik (Subansiri Formation), while the rest are from the Upper Siwalik (Kimin Formation). The modern analogues of the fossils from the Middle Siwalik are Lophopetalum littorale (Celastraceae), Afzelia-Intsia and Sindora siamensis (Fabaceae) and from the Upper Siwalik are Miliusa velutina (Annonaceae), Calophyllum tomentosum and Kayea (Calophyllaceae) and Diospyros melanoxylon (Ebenaceae). The dominance of diffuse porosity in the fossil woods indicates a tropical climate with low seasonality (little variation) in temperature, while a high proportion of large vessels and simple perforation plates in the assemblage infer high precipitation during the deposition of the sediments. The aforesaid inference is in strong agreement with the previous quantitative reconstruction based on fossil leaves. Several modern analogues of the fossil taxa are now growing in low latitudes possibly due to an increase in seasonality (increased variation) in temperature caused by the rising Himalaya. 相似文献