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Seasonal and Interannual Variations of Upper Tropospheric Water Vapor Band Brightness Temperature over the Global Monsoon Regions 被引量:2
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作者 钱维宏 朱亚芬 +1 位作者 谢安 叶谦 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1998年第3期55-63,共9页
The upper-troposphere water vapor (UTWV) band brightness temperature (BT) dataset derived from the High-resolution Infrared Radiation Sounder (HIRS) channel 12 of the National Oceanic and Atmospheric Administration (N... The upper-troposphere water vapor (UTWV) band brightness temperature (BT) dataset derived from the High-resolution Infrared Radiation Sounder (HIRS) channel 12 of the National Oceanic and Atmospheric Administration (NOAA) polar satellites from 1979 to 1995 is used to analyze the seasonal and interannual variations for the global monsoon regions. Results show that (i) there are three major regions where the UTWV band BT varies significantly with season, i.e., South Asia, the western coastal South-North America tropical region and the low-latitude African region; (ii) UTWV band BT clearly reveals the water vapor temporal/spatial features as well as the atmospheric circulation structure over the low-latitude during the monsoon onset; and (iii) there is a remarkable relationship between the interannual variation of the UTWV band BT over the monsoon regions and the sea surface temperature anomaly in the eastern equatorial Pacific. 展开更多
关键词 MONSOON Seasonal variation Interannual variability upper tropospheric water vapor Brightness temperature
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Solar forced transient evolution of Pacific upper water thermal structure during the Holocene in an earth system model of intermediate complexity 被引量:1
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作者 WANG Yue JIAN ZhiMin +2 位作者 ZHAO Ping DANG HaoWen XIAO Dong 《Chinese Science Bulletin》 SCIE EI CAS 2013年第15期1832-1837,共6页
Forced by transient solar activities since 7 ka,the thermal structures of the Pacific upper water at boreal winter are featured by an enhanced response of 3-dimensional Western Pacific Warm Pool(WPWP) in an Earth syst... Forced by transient solar activities since 7 ka,the thermal structures of the Pacific upper water at boreal winter are featured by an enhanced response of 3-dimensional Western Pacific Warm Pool(WPWP) in an Earth system model of Intermediate Complexity at centennial scales.During solar maximum periods,the magnitude of surface ocean temperature variations is 30% larger in the western tropical Pacific than in the Ni o3 region,while at subsurface,it is 40% larger in the subtropical North Pacific than in the western Equatorial Pacific.They compromise stronger zonal and meridional thermal gradients in surface and subsurface Pacific respectively which are both linearly responded to solar forcing at centennial periods.The surface gradient is most sensitive at 208-year period while the subsurface gradient shows more significance at periods longer than 208-year.Also noteworthy are two differences:(1) the phase lags at these periods of surface gradient are slightly smaller than that of subsurface;(2) the 148-year and 102-year periods in surface gradient are lost in subsurface gradient.These modeled features preliminary confirm the centennial fluctuations of WPWP in paleo-proxies and a potential solar forcing during the Holocene. 展开更多
关键词 西太平洋暖池 地球系统 太阳能 全新世 热结构 瞬态 上层 海洋表面
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Retrieval of Upper Tropospheric Relative Humidity by the GMS-5 Water Vapor Channel:A Study of the Technique 被引量:1
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作者 黄毅 王美华 毛节泰 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第1期53-60,共8页
This paper presents an analysis of a technique for retrieving upper tropospheric relative humidity through the GMS-5 satellite's 6.7-micron water vapor channel brightness temperature. NCEP analysis shows that a cr... This paper presents an analysis of a technique for retrieving upper tropospheric relative humidity through the GMS-5 satellite's 6.7-micron water vapor channel brightness temperature. NCEP analysis shows that a critical assumption of the retrieval theory, namely the constant temperature lapse rate, matches only in the tropical atmosphere. By statistical analyses of brightness temperature simulated by a radiative transfer model and of relative humidity, we examine the effect of lapse rate on this retrieval method and obtain retrieval parameters and error estimates applicable to the GMS-5 satellite over East Asia. If the retrieval parameters are properly chosen, the relative error of retrieving the upper tropospheric relative humidity in this region is less than 10%, and if applied to the low-latitude summer atmosphere, it is less than 5%. 展开更多
关键词 upper troposphere water vapor satellite retrieval brightness temperature
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Assessment of Climate Change Impact on Water Resources in the Upper Senegal Basin (West Africa) 被引量:3
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作者 Mamadou Lamine Mbaye Stefan Hagemann +3 位作者 Andreas Haensler Tobias Stacke Amadou Thierno Gaye Abel Afouda 《American Journal of Climate Change》 2015年第1期77-93,共17页
This study assesses the potential impacts of climate change on water resources and the effect of statistical bias correction on the projected climate change signal in hydrological variables over the Upper Senegal Basi... This study assesses the potential impacts of climate change on water resources and the effect of statistical bias correction on the projected climate change signal in hydrological variables over the Upper Senegal Basin (West Africa). Original and bias corrected climate data from the regional climate model REMO were used as input for the Max Planck Institute for Meteorology-Hydrology Model (MPI-HM) to simulate river discharge, runoff, soil moisture and evapotranspiration. The results during the historical period (1971-2000) show that using the bias corrected input yields a better representation of the mean river flow regimes and the 10th and 90th percentiles of river flow at the outlet of the Upper Senegal Basin (USB). The Nash-Sutcliffe efficiency coefficient is 0.92 using the bias corrected input, which demonstrates the ability of the model in simulating river flow. The percent bias of 3.88% indicates a slight overestimation of the river flow by the model using the corrected input. The evaluation demonstrates the ability of the bias correction and its necessity for the simulation of historical river regimes. As for the potential changes of hydrological variables by the end of 21st century (2071-2100), a general decrease of river discharge, runoff, actual evapotranspiration, soil moisture is found under two Representative Concentration Pathways (RCP4.5 and RCP8.5) in all simulations. The decrease is higher under RCP8.5 with uncorrected data in the northern basin. However, there are some localized increases in some parts of the basin (e.g. Guinean Highlands). The projected climate change signal of these above variables has the same spatial pattern and tendency for the uncorrected and bias corrected data although the magnitude of the corrected signal is somewhat lower than that uncorrected. Furthermore, the available water resources are projected to substantially decrease by more than -50% in the majority of the basin (especially in driest and hottest northern basin with RCP8.5 scenario) for all data, except the Guinean highlands where no change is projected. The comparison of simulations driven with uncorrected and bias corrected input reveals that the bias correction does not substantially change the signal of future changes of hydrological variables for both scenarios over the USB even though there are differences in magnitude and deviations in some parts of the basin. 展开更多
关键词 Climate Change Impact Signal BIAS Correction upper Senegal BASIN water RESOURCES
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Water masses classification of the upper layer in the Equatorial Western Pacific using ISODATA of fuzzy cluster 被引量:1
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《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第2期187-201,共15页
-In this paper,by using ISODATA of fuzzy cluster,the water masses classification of the upper layer in the E-quatorial Western Pacific is carried out. On the basis of the degree of the membership in the obtained optim... -In this paper,by using ISODATA of fuzzy cluster,the water masses classification of the upper layer in the E-quatorial Western Pacific is carried out. On the basis of the degree of the membership in the obtained optima) classification matrix, the solid distribution of the detailed structure of water masses is made. The water of the upper layer,consisting of six water masses,may be divided into three layers,i, e. ,the surface,subsurface and intermediate layer. Besides analyzing the features of various water masses,a discussion on their distribution structure and formation mechanism is also made. 展开更多
关键词 water masses classification of the upper layer in the Equatorial Western Pacific using ISODATA of fuzzy cluster ISODATA
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Based on the Theory of Optimizing the Allocation of Research of Sustainable Utilization of Water Resources of the Upper Reaches of Minjiang River
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作者 Canyuan Liu 《Natural Resources》 2020年第10期473-498,共26页
<span style="font-family:""><span style="font-family:Verdana;">Water resource is an important supporting material for life support system and eco</span><span style="f... <span style="font-family:""><span style="font-family:Verdana;">Water resource is an important supporting material for life support system and eco</span><span style="font-family:Verdana;">nomic development, and the sustainable development and utilization of water resource </span></span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> the guarantee of social sustainable development. The upper Minjiang River is the most important source of water supply for the Chengdu Plain. With the water resources of the upper Minjiang River facing the problems of overall water volume reduction, flood and water pollution, etc.</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> based on the optimal allocation theory, this paper constructs an optimal allocation model of water resourc</span><span style="font-family:Verdana;">es in the upper reaches of the Minjiang River, analyzes its characteristics and proposes some relevant countermeasures and suggestions to solve the existing problems, aiming to provide reference</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> for the sustainable utilization of water resources in the upper reaches of the Minjiang River. 展开更多
关键词 The upper Reaches of Minjiang River water Resources Optimized Configuration
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Changing water regime and adaptation strategies in Upper Mustang Valley of Upper Kaligandaki Basin in Nepal
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作者 Prem Sagar Chapagain Jagat K. Bhusal 《Research in Cold and Arid Regions》 CSCD 2013年第1期133-139,共7页
Recent climate change has brought changes to the water regime that has affected the traditional agro-pastoral production systems and livelihoods in the Upper Kaligandaki Basin of the Nepal Himalayas. Based on fieldwor... Recent climate change has brought changes to the water regime that has affected the traditional agro-pastoral production systems and livelihoods in the Upper Kaligandaki Basin of the Nepal Himalayas. Based on fieldwork and available meteorological and hydrological data, this paper examines the changing water regime and various adaptation strategies that local farmers have adopt- ed in this cold alid region. Increasing temperature and decreasing min|hll and snowfall have resulted in a negative water balance. In this scenario, lhmlers have implemented six major adaptive strategies in the trans-Himalayan Upper Mustang Valley. 展开更多
关键词 upper Kaligandaki Fanning: livelihoods climate change water balance adaptation strategies
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Climate Influenced Challenges of Accessibility to Water by Households Downstream of the Upper Benue River Basin-Nigeria
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作者 Vincent Nduka Ojeh Shadrach Terlumun Semaka 《Atmospheric and Climate Sciences》 2021年第1期53-72,共20页
The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study... The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study adopted a descriptive survey design. The population of the study consisted of communities in Adamawa, Gombe, Bauchi and Taraba states. Eight different communities, two in each local government were sampled for the study. Simple random and purposive samplings were used for the study. A total of 351 respondents were selected for the study using Krejcie and Morgan sample size determination. Data analysis was done using frequency tables percentages and mean statistics. The findings of the study showed that climate variability has great impact on water stress and threats to households’ downstream in Upper Benue River basin represented with a mean 3.85 (decrease in the quality and quantity of surface water) as well as 3.43 (drying up of rivers and lakes). The study also revealed that water stress induced by climate variability has a significant effect on household livelihoods represented by 87% of the respondents in the study area. It was also revealed that that households downstream the basin are vulnerable to climate change and households in the study area have development strategies to contend with water stress so as to better their livelihood among which is surface water harvesting (2.78), reducing the number of times dishes are washed (2.96), reducing the quantity of water used for bathing (3.0) among others. The study recommended that stakeholders and the government should make proactive efforts to ensuring that alternative water sources are established in the study area to reduce water stress among the rural populace. 展开更多
关键词 upper Benue River Basin ACCESSIBILITY Households water Challenges
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Evaluation of Water Quality Index in Lerma River Upper Basin
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作者 Icela D. Barceló-Quintal Mónica L. Salazar-Peláez +3 位作者 Julisa García-Albortante Eloisa Domínguez-Mariani Ulrico J. López-Chuken Sergio Gómez-Salazar 《Journal of Environmental Protection》 2013年第7期98-103,共6页
The Lerma River Upper Basin is located between Almoloya del Rio shallow lakes and Atlacomulco Municipality in the State of Mexico;is a natural resource essential to human activities in its surroundings and serves as a... The Lerma River Upper Basin is located between Almoloya del Rio shallow lakes and Atlacomulco Municipality in the State of Mexico;is a natural resource essential to human activities in its surroundings and serves as a source of electricity and drinking water for Mexico City. However, this river is threatened by over-exploitation of its aquifers, disappearance of many of its wellsprings and uncontrolled discharges of wastewater from all sorts. Thus, the aim of this work was to evaluate the water quality in the Upper Lerma River Basin using WQI proposed by the NSF and compare these results with those obtained by the National Water Commission of Mexico (CNA). WQI was calculated using seven parameters: dissolved oxygen, pH, DOB5, temperature change, total phosphates, nitrates, and total solids obtained in four different sampling campaigns carried out in 2005, 2006 and 2012. The results showed that water quality in the Upper Lerma River is bad, mainly associated with high levels of BOD5, nitrates and phosphates found. The results obtained with WQI yielded the same diagnosis that the studies carried out by the CNA, in which water quality was unacceptable. It is worth noting that there is a significant water quality deterioration in the Upper Lerma River Basin with the course of the years, because in 2012 were observed the lower index values regarding 2005 and 2006, so it is imperative to implement measures to restore and preserve the water quality of this important river. 展开更多
关键词 water Quality INDEX Lerma RIVER upper BASIN BOD5 NITRATES PHOSPHATES
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Water Purification Capacity of Four Kinds of Aquatic Plants in the Upper Reaches of Luanhe River
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作者 YUAN Wenge ZHENG Jianwei +2 位作者 GU Jiancai LU Guiqiao YU Xinxiao 《Journal of Landscape Research》 2018年第6期51-55,59,共6页
Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic... Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic plants and their configurations showed purification effects for total nitrogen(TN), nitrate nitrogen(NO_3^-), total phosphorus(TP), orthophosphate(PO_4^(3-)) and chemical oxygen demand(COD) in water body, and the purification effects of aquatic plant configurations were better than those of single ones. Regression analysis was conducted for dynamics of various water quality indicators. The removal rates of TN and COD within 50 d by the combination of L. salicaria and I. wilsonii were 73.83% and 77.4%, respectively, with the best purification effect; the removal rate of NO_3^- within 20 d by the combination of S. validus and I. wilsonii was 89.41%; and the combination of S. validus and I. wilsonii showed the best removal effect for TP and PO43-, of which the 50-d removal rates were 88.98% and 92.39%, respectively. Reasonable choice of local aquatic plants and their optimal combinations can be applied in the improvement of water quality of rivers. 展开更多
关键词 upper reaches of Luanhe RIVER AQUATIC PLANTS CONFIGURATION water PURIFICATION
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Impact of Surface Water and Groundwater Pollutions on Irrigated Soil, El Minia Province, Northern Upper Egypt
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作者 Rafat Zaki Esam A. Ismail +1 位作者 Wagih S. Mohamed Ali Kamel Ali 《Journal of Water Resource and Protection》 2015年第17期1467-1472,共6页
Current research has been focused on heavy metals pollution in surface water and groundwater and effect on irrigated soil from El Minia Province, north Upper Egypt. Concentration of heavy metals (e.g., As, Co, Hg, Ni,... Current research has been focused on heavy metals pollution in surface water and groundwater and effect on irrigated soil from El Minia Province, north Upper Egypt. Concentration of heavy metals (e.g., As, Co, Hg, Ni, Se, Cd and Cr) in surface water, groundwater and irrigated soil samples is most significantly affected by leachate of many pollutants as the factories, agricultural activities, urban and natural processes. Microbiological parameters and microscopic investigations are revealed that some localities are common by micro-organisms, which are unsuitable for drinking waters. 展开更多
关键词 Heavy Metals Pollution Surface water Groundwater Soils EL Minia PROVINCE North upper EGYPT
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基于水量平衡的澳洲坚果灌溉制度研究
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作者 裴鼎 余航 +3 位作者 潘梦楠 何洋 唐红燕 王丽 《江西农业学报》 2025年第1期84-91,共8页
基于澜沧气象站1958-2017年的实测气象资料,采用作物系数法和水量平衡法计算澳洲坚果各生育期的作物需水量及不同典型年的灌溉定额,利用灌水上、下限的差值制定了适宜的灌溉制度。澳洲坚果在丰水年、平水年、中等干旱年及特枯年的需水... 基于澜沧气象站1958-2017年的实测气象资料,采用作物系数法和水量平衡法计算澳洲坚果各生育期的作物需水量及不同典型年的灌溉定额,利用灌水上、下限的差值制定了适宜的灌溉制度。澳洲坚果在丰水年、平水年、中等干旱年及特枯年的需水量分别为829.55、844.99、875.24、915.07 mm,各生育期的需水量由大到小依次为:成熟期—采摘期>果实膨大期>萌芽期—花期>休眠期。各典型年的作物系数基本不变,萌芽期—花期(休眠期)、果实膨大期、成熟期—采摘期的作物系数分别为0.33、0.91、0.76。不同灌水上、下限的差值会影响灌溉定额和灌溉制度,当差值大于6.0%时,灌溉定额保持不变,约为237.5 mm;当差值小于6.0%时,灌溉定额随差值减小而减小,当差值较小时,灌溉次数增多,灌水规律不一致;而当差值为3.3%时,制定的灌溉制度更为合理,即分别取灌水上限(19.8%)、下限(16.5%),在灌溉保证率分别为25%、50%、75%、95%时,灌溉定额分别为1921.65、2149.35、2317.50、2652.30 m^(3)/hm^(2),灌溉次数分别为16、18、19、21次。最适宜的灌水上、下限的差值为3.3%,在此条件下制定的灌溉制度科学合理且能够提高水资源的利用效率。研究结果可为目前缺少试验资料的澳洲坚果灌溉管理、灌溉工程规模确定和农业水资源高效利用提供科学依据。 展开更多
关键词 澳洲坚果 作物需水量 灌水上下限 灌溉制度
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Progress in Chinese research on water masses and circulation in the Arctic and subarctic ocean 被引量:2
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作者 CAO Yong ZHAO Jinping SHAO Qiuli 《Advances in Polar Science》 2017年第2期91-99,共9页
The Arctic Ocean and Arctic sea ice have undergone a series of rapid changes. Oceanographic surveying has become one of the key missions of the Chinese National Arctic Research Expeditions since 1999. Using the data o... The Arctic Ocean and Arctic sea ice have undergone a series of rapid changes. Oceanographic surveying has become one of the key missions of the Chinese National Arctic Research Expeditions since 1999. Using the data obtained in these surveys and from other sources, Chinese researchers have carried out a series of studies in the field of Arctic physical oceanography. The Near Sea-surface Temperature Maximum, freshwater content and heat flux in different regions of the Arctic have drawn wide attention from Chinese researchers. Arctic circulation is changing with the decline of sea ice, which is also influencing the structure and distribution of water masses. Studies have also focused on these issues. In this paper, the main results of research on water masses, currents, the structure of the upper ocean and other major hydrological phenomena over the past two decades are summarized. 展开更多
关键词 Arctic Ocean physical oceanography upper ocean water mass CURRENT
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Geochemical Criteria of the Upper Sinian Cherts of Hydrothermal Origin on the Southeast Continental Margin of the Yangtze Plate 被引量:2
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作者 彭军 伊海生 夏文杰 《Chinese Journal Of Geochemistry》 EI CAS 2000年第3期217-226,共10页
The Upper Sinian bedded cherts are widely distributed on the southeast continental margin of the Yangtze plate, with a total thickness ranging from 20 to 150 m. The cherts are very simple in chemical composition, with... The Upper Sinian bedded cherts are widely distributed on the southeast continental margin of the Yangtze plate, with a total thickness ranging from 20 to 150 m. The cherts are very simple in chemical composition, with the contents of siliceous minerals exceeding 90% and those of other mineral species being very low. The total content of trace elements is considerably variable. The contents of most trace elements are low as compared with their crust clarke values. But these cherts are very rich in the trace elements Ba, As, Ab, Ag and U, coupled with relatively high contents of Fe, Mn and low contents of Al, Ti, and Mg. It can be identified as the cherts of hydrothermal origin in terms of the values of Fe/Ti, (Fe+Mn)/Ti, Al/(Al+Fe+Mn) and U/Th. In the Al\|Fe\|Mn, and Fe\|Mn\|(Cu+Ni+Co)×10 diagrams and lg \\|lg\, Cr\|Zr diagrams, all the samples from the area studied fall within the hydrothermal sediment field. All these characteristics show that the cherts are mainly the product of hydrothermal processes. The fact that the \{δ\{\}\+\{30\}Si\} values of the chert range from 0.0‰ to \{0.7‰\} with \{δ\{\}\+\{18\}O\} from 20.1‰ to 23.6‰ clearly manifests that the submarine hydrothermal water is the main source of silica.\;\; 展开更多
关键词 燧石 热水作用 地球化学 上震旦纪 贵州 四川
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Impact of Mid-and Upper-Level Dry Air on Tropical Cyclone Genesis and Intensification:A Modeling Study of Durian(2001) 被引量:5
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作者 Yaping WANG Yongjie HUANG Xiaopeng CUI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第12期1505-1521,共17页
The impact of mid-and upper-level dry air,represented by low relative humidity(RH)values,on the genesis of tropical cyclone(TC)Durian(2001)in the South China Sea was investigated by a series of numerical experiments u... The impact of mid-and upper-level dry air,represented by low relative humidity(RH)values,on the genesis of tropical cyclone(TC)Durian(2001)in the South China Sea was investigated by a series of numerical experiments using the Weather Research and Forecasting model.The mid-level RH was lowered in different regions relative to TC Durian(2001)’s genesis location.Results suggest that the location of dry air was important to Durian(2001)’s genesis and intensification.The rapid development of the TC was accompanied by sustained near-saturated mid-and upper-level air,whereas low humidity decelerated its development.Water vapor budget analysis showed that moisture at mid and upper levels was mainly supplied by the vertical convergence of moisture flux and the divergence terms,and consumed by the condensation process.The horizontal convergence of moisture flux term supplied moisture in the air moistening process but consumed moisture in the air drying process.With a dryer mid-and upper-level environment,convective and stratiform precipitation were both inhibited.The upward mass fluxes and the diabatic heating rates associated with these two precipitation types were also suppressed.Generally,convection played the dominant role,since the impact of the stratiform process on vertical mass transportation and diabatic heating was much weaker.The vorticity budget showed that the negative vorticity convergence term,which was closely related to the inhibited convection,caused the vorticity to decrease above the lower troposphere in a dryer environment.The negative vorticity tendency is suggested to slow down the vertical coherence and the development rate of TCs. 展开更多
关键词 tropical cyclone formation mid-and upper-level dry air WRF water vapor budget convective and STRATIFORM precipitation
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Constitution Water in Mantle-derived Megacryst and Xenolith Pyroxene of an Ultrabasic Pipe in Anyuan, Jiangxi 被引量:2
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作者 叶松 张保民 +2 位作者 狄敬如 杨眉 叶德隆 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第3期339-342,共4页
This paper studies the hydrous facies of mantle-derived megacrystclinopyroxenes and pyroxenes of xenoliths of pyroxenolite and spinel peridotite as well as garnetpyroxenolite in a kimberlitic lamprophyre pipe in Anyua... This paper studies the hydrous facies of mantle-derived megacrystclinopyroxenes and pyroxenes of xenoliths of pyroxenolite and spinel peridotite as well as garnetpyroxenolite in a kimberlitic lamprophyre pipe in Anyuan, Jiangxi, by Fourier Transform Infrared(FTIR). It explores the relationship between the water content of pyroxene on the one hand and itscomposition and source depths on the other hand. All the samples contain constitution water. Spectraof the clinopyroxene are dominated by two groups of bands: 3607-3630 cm^(-1) and 3522-3542 cm^(-1).Spectra of the orthopy-roxene are dominated by three groups of bands: 3410-3424 cm^(-1), 3510-3516cm^(-1) and 3560-3595 cm^(-1). The water content of the clinopyroxenes has a positive correlationwith their FeO and Al_2O_3 contents. The source depths of mantle-derived clinopyroxene megacrysts,pyroxenolite, spinel peritotite and garnet pyroxenelite increase gradually in order. The Al_2O_3 andwater contents of four pyroxenes have similar correlation with the source depths. 展开更多
关键词 PYROXENE constitution water infrared spectroscopy kimberliticlamprophyre upper mantle JIANGXI Anyuan
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From Where Did the Water Come That Filled the Earth’s Oceans? A Widely Overlooked Redox Reaction
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作者 Friedemann T. Freund Minoru M. Freund 《American Journal of Analytical Chemistry》 2015年第4期342-349,共8页
Though two-thirds of Earth’s surface is covered by oceans, measurements of hydroxyl concentrations in upper mantle minerals, specifically in olivine, reportedly provide surprisingly low values. This has been interpre... Though two-thirds of Earth’s surface is covered by oceans, measurements of hydroxyl concentrations in upper mantle minerals, specifically in olivine, reportedly provide surprisingly low values. This has been interpreted to mean that there is little dissolved H2O in the Earth’s mantle. By inference, when Earth formed, there might not have been able enough water to fill the oceans through volcanic degassing. It has therefore been proposed that the missing water was delivered to Earth from space, through comets and other impacting bodies. However, the reported low hydroxyl concentrations in olivine and similar mineralsis probably based on a profound misunderstanding of a solid state reaction that converts hydroxyls into something more difficult to detect. There is indeed a redox reaction that converts, during cooling, solute hydroxyls in the matrix of minerals into peroxy plus H2. This widely overlooked redox conversion takes place under thermodynamic non-equilibrium conditions. Its significance is that any mineral and any rock available for collection at the Earth surface has gone through a process that causes hydroxyls, the telltale sign of dissolved H2O, to change into peroxyplusH2. The H2 molecules are diffusively mobile and may leave even structurally dense mineral grains. The remaining peroxy thus become the memory of the “true” solute H2O content, besides a few residual hydroxyls. Though first described over 30 years ago, this redox conversion has been largely ignored. As a result it is unknown how much H2O is contained in the Earth’s upper mantle but it is certainly much more than has been assumed until now on the basis of analysis of residual hydroxyls. 展开更多
关键词 Redox Conversion HYDROXYLS Peroxy water Earth’s upper MANTLE
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柴达木盆地南八仙地区渐新世浅水三角洲物源及沉积演化 被引量:1
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作者 易定红 石亚军 +6 位作者 刘俊丰 刘应如 李积永 王爱萍 马元坤 李红哲 贾正良 《地质学报》 EI CAS CSCD 北大核心 2024年第2期494-510,共17页
以古近系渐新统下干柴沟组上段(E23)为研究对象,在精细岩芯观察和钻(测)井资料综合分析的基础上,结合重矿物组合、ZTR指数、砂岩碎屑组分、粒度累积概率图和砂地比等参数综合分析结果,对柴达木盆地南八仙地区E23湖盆扩张期弱退积型浅水... 以古近系渐新统下干柴沟组上段(E23)为研究对象,在精细岩芯观察和钻(测)井资料综合分析的基础上,结合重矿物组合、ZTR指数、砂岩碎屑组分、粒度累积概率图和砂地比等参数综合分析结果,对柴达木盆地南八仙地区E23湖盆扩张期弱退积型浅水三角洲物源方向、砂体展布规律和沉积微相发育演化进行了深入研究。结果表明:①南八仙地区E23沉积时期物源主要来自南祁连山中酸性岩浆岩和中高级变质岩发育区,物源方向为近北东—南西向,稳定重矿物(磁铁矿、石榴子石、白钛矿和锆石)含量高(质量分数介于81.0%~99.9%)、不稳定重矿物(绿帘石和角闪石)含量低。②南八仙地区E23沉积时期为浅水三角洲—滨浅湖沉积环境,主要发育水下分流河道砂体,岩性主要为岩屑长石砂岩,其次为长石岩屑砂岩,砂体的成分成熟度一般中等—较差、分选磨圆度中等—较差,粒度概率图以反映河流作用的一跳跃一悬浮式为主;沉积构造类型多样,主要发育块状层理、正粒序层理、平行层理和槽状交错层理。③E23沉积时期,南八仙地区继承性发育3条北东—南西向呈条带状展布的砂体富集带(砂地比值介于35%~65%之间),早期到中期砂体发育程度增强,呈进积式;中期到晚期砂体发育程度有所减弱,呈弱退积式。④E23沉积时期,南八仙地区处于浅水三角洲前缘亚相沉积环境,持续发育3个呈北东—南西向展布的沉积朵叶体,主要发育水下分流河道微相,其次为水下分流间湾微相,早期到中期浅水三角洲前缘发育规模增大,中期到晚期发育规模减小。 展开更多
关键词 浅水三角洲 物源方向 下干柴沟组上段 渐新世 南八仙地区 柴达木盆地
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Estimation of petrophysical parameters using seismic inversion and neural network modeling in Upper Assam basin, India 被引量:3
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作者 Triveni Gogoi Rima Chatterjee 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第3期1113-1124,共12页
Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from... Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively. 展开更多
关键词 upper ASSAM BASIN Relative acoustic impedance POROSITY Volume of SHALE water SATURATION Neural network model
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Distribution Regularity of Debris Flow and Its Hazard in Upper Reaches of Yangtze River and Other Rivers of Southwestern China 被引量:1
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作者 WEI Fangqiang JIANG Yuhong CUI Peng DING Mingtao 《Wuhan University Journal of Natural Sciences》 CAS 2007年第4期619-626,共8页
In the upper reaches of Yangtze River and other rivers of southwestern China, the debris flows develop and lead to most serious disasters because of the various landforms, complex geological structures and abundant ra... In the upper reaches of Yangtze River and other rivers of southwestern China, the debris flows develop and lead to most serious disasters because of the various landforms, complex geological structures and abundant rainfall. The distribution of debris flows has regularity in the regions with different landform, geological structure, and precipitation. The regularities of distribution of debris flows are as following: (1) distributed in transition belts of different morphologic regions; (2) distributed in the area with strong stream trenching; (3) distributed along fracture zones and seismic belts: (4) distributed in the area with abundant precipitation; (5) distribution of debris flow is azonal. The activity of abundant debris flows not only brings harm to Towns, Villages and Farmlands, Main Lines of Communication, Water-Power Engineering, Stream Channels etc., but also induces strong water and soil loss. According to the present status of debris flow prevention, the problems in disasters mitigation and soil conservancy are found out, and the key works are brought up for the future disasters prevention and soil conservancy. 展开更多
关键词 upper reaches of Yangtze River southwestern China debris flow water and soil loss distribution and hazards of debris flow
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