期刊文献+
共找到4,554篇文章
< 1 2 228 >
每页显示 20 50 100
Origin of the Yueguang gold deposit in Xinhua, Hunan Province, South China: insights from fl uid inclusion and hydrogen–oxygen stable isotope analysis
1
作者 Hongxin Fan Qiang Wang +2 位作者 Yulong Yang Yao Tang Hao Zou 《Acta Geochimica》 EI CAS CSCD 2024年第2期235-254,共20页
The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,w... The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province. 展开更多
关键词 hunan province Yueguang gold deposit Fluid inclusions Hydrogen–oxygen isotopes Laser Raman Fluid immiscibility Orogenic gold deposit
下载PDF
Analysis of Emergy Structure,Function and Efficiency of Agro-ecosystem in Hunan Province 被引量:1
2
作者 朱玉林 李明杰 +2 位作者 侯茂章 龙雨孜 王茂溪 《Agricultural Science & Technology》 CAS 2013年第1期186-192,共7页
[Objective] The aim was to explore function and efficiency of emergy input/ output of Hunan agricultural ecosystem to reveal relationship of human being with natural resources and environment. [Method] Emergy structur... [Objective] The aim was to explore function and efficiency of emergy input/ output of Hunan agricultural ecosystem to reveal relationship of human being with natural resources and environment. [Method] Emergy structure, function and efficien- cy of Hunan agricultural ecosystem were analyzed based on input/output data in Hunan Province in 2009 as per emergy theory. [Result] The structure characters of agricultural ecosystem were as follows: Hunan is characterized with traditional agri- culture, depending greatly on both human and animal labor. For industrial accessory emergy, chemical fertilizers make most contribution to the system, and agricultural mechanization is not satisfied. Furthermore, renewable ratio of industrial accessory emergy is lower, and development and potential of green energy is promising. In addition, prices of the products are lower, without consideration of contribution made by natural resources and environment. It also suggested that Hunan agricultural chain is short and added value of products is not high. In general, emergy output of farming and animal husbandry dominates and the prices are lower than those of forestry and fishery. The function of the system was as follows: With lower environ- mental load ratio, the system is overloaded by population and the index of sustain- able development was 5.96, suggesting that the system enjoys vitality and potential, but the economy is undeveloped and the pressure from natural resources and envi- ronment is not high. The emergy output ratio was a little lower than national level in 2009, suggesting Hunan agricultural production is extensive. [Conclusion] The re- search indicated that rapid increase of population should be controlled; surplus labor should be transferred; agricultural structure and products structure should be further adjusted; agricultural technology should be further developed; agdcultural mechaniza- tion and modernization should be improved. 展开更多
关键词 Energy analysis STRUCTURE FUNCTION EFFICIENCY Agriculture of hunan province introduction
下载PDF
Analysis of Change of Cultivated Land and Grain Production in Hunan Province 被引量:1
3
作者 谢红霞 谢永红 +2 位作者 王翠红 杨君 袁红 《Agricultural Science & Technology》 CAS 2011年第9期1327-1330,共4页
[Objective] This paper aimed at exploring the countermeasures for cultivated land protection and food security assurance and providing references for the formulation of policies related to cultivated land and grain pr... [Objective] This paper aimed at exploring the countermeasures for cultivated land protection and food security assurance and providing references for the formulation of policies related to cultivated land and grain production of the whole province.[Methods] Data of population,cultivated land,grain and others in Hunan Province during 1989 to 2008 were collected by county(district).The changes of cultivated land and grain production of the whole province were analyzed using Geographical Information System(GIS).[Results] The population was increasing continuously,the total area of cultivated land was reducing as a whole in spite of increasing in one or two year in one or two county,the total grain production and per capita grain yield was fluctuated within a certain range in recent 20 years of the whole province.The reducing of cultivated land was mainly due to the industrialization and urbanization development.The unbalanced quantity and quality of cultivated land,various natural disasters,readjustment of industry structure and inner readjustment in the agriculture,variety improvement and improvement of cultivated technology mainly affected of the grain production.[Conclusions] The protection of the quantity and quality of cultivated land has to be strengthened to ensure food security.It is important to enhance the ability of resisting drought and flood disasters by improving the construction of agriculture establishment in order to insure the productivity of cultivated land,to increase farmer’s enthusiasm for growing grain with favourable food policy,to improve the per unit area yield of grain by variety improvement and to increase grain sown area by enlarging the double-cropping rice sown area. 展开更多
关键词 hunan province Cultivated land GRAIN
下载PDF
Emergy analysis of paddy farming in Hunan Province, China: A new perspective on sustainable development of agriculture 被引量:6
4
作者 YI Ting XIANG Ping-an 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第10期2426-2436,共11页
The multi-functionality of paddy farming has become a hot issue recently. Paddy farming provides numerous ecosystem services that are crucial to human well-being. However, evaluation of the contribution of paddy farmi... The multi-functionality of paddy farming has become a hot issue recently. Paddy farming provides numerous ecosystem services that are crucial to human well-being. However, evaluation of the contribution of paddy farming to human well-being usually focus on its economic value, while its non-market services are usually ignored. Only evaluating the market profits or market relative benefits cannot reflect comprehensively the contribution of paddy farming to people's well-being. This will affect people's choices for or against paddy farming activities and people's opt for invest or not invest in it. A comprehensive evaluation of paddy farming can provide an important reference for the government and society to conserve the multi-functionality of paddy farming and achieve sustainable development. To this end, this paper reports a case evaluation of paddy farming in Hunan, the largest rice producing as well as rice yield province in China, and uses emergy theory to make a comprehensive evaluation for paddy farming. The emergy evaluation results of the paddy ecosystem in Hunan are as follows: in 2010, the input emergy of the paddy ecosystem in Hunan is 2.51E+22 sej and the output emergy is 6.31E+22sej. For the input emergy, the part from natural resources is 1.96E+21 sej and the part from human society is 2.32E+22sej; for the output emergy, the part from products is 2.22E+22 sej, the part from impositive externality is 4.16E+22 sej and the part from negative externality is –7.41E+20 sej. Taking the non-market outputs into consideration, the gains from the human economic society's 1 $ input in paddy farming, emergy sustainability index(ESI) and emergy profit rate are respectively 2.73 $, 3.53 and 151.31%. If the evaluation leave out the non-market output, the three indexes are only 0.96 $,1.24 and 30.67%. The research results show that non-market services of paddy farming contribute significantly to human well-being. Therefore, in order to protect the multi-functionality of paddy farming and achieve the sustainable management,the government should take reasonable measures and make incentive plans. 展开更多
关键词 paddy farming emergy analysis ecosystem services hunan province
下载PDF
A New Species of the Genus Tylototriton (Urodela: Salamandridae) from Northeastern Hunan Province, China 被引量:5
5
作者 Daode YANG Jianping JIANG +1 位作者 Youhui SHEN Dongbo FEI 《Asian Herpetological Research》 SCIE 2014年第1期1-11,共11页
We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.a... We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.asperrimus group,and shares a number of similarities with T.wenxianensis and T.broadoridgus.The dorsal surface of the new Tylototriton species is completely black,with nodule-like warts distributed evenly along the lateral margin of dorsal body,and there is no transverse striae between the warts.There are several diagnostic characters of the new species that differ from those of T.wenxianensis and T.broadoridgus as follows:(1)the interorbital space(IOS)is comparatively wide;(2)there is a bony ridge present on the dorsal head surface,running along the upper eyelids;(3)the space between axilla and groin(AGS)is comparatively large,with the mean male AGS approximately equal to 50%of the snout-vent length(SVL)and the mean female AGS being 53%of SVL;and(4)there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season.The result from the molecular phylogenetic analysis of the genus Tylototriton(including the type specimen of the new species)based on the complete DNA sequence of the mitochondrial ND2 gene(1035 bp)indicated that the new species was similar to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,supporting that the Liuyang Population represented a distinct species. 展开更多
关键词 new species Tylototriton liuyangensis Salamandridae taxonomy Liuyang Daweishan Provincial Nature Reserve of hunan province in China
下载PDF
Analysis of an Abrupt Rainstorm Process in Central Hunan Province 被引量:1
6
作者 YANG Ling YAO Rong +3 位作者 LIU Zhi-xiong ZHOU Bin WANG Le-hui ZHANG Zi-xin 《Meteorological and Environmental Research》 CAS 2011年第8期43-47,77,共6页
[Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation a... [Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation and FY-2C satellite data,the large-scale circulation background and physical condition during the large rainstorm period from the night on May 5 to 6 in 2010 were analyzed.The large scale environment,meso-scale characteristics and potential causes for the formation of large precipitation were revealed.By dint of FY-2D satellite and water-vapor cloud image,infrared cloud image,4 black light temperature,the variation characteristics of heavy rainstorm convection system were analyzed.[Result] Under the favorable environment background,the rainstorm was induced by the meso-scale convection system,and it had close relation with the upper-air trough,shear line in the middle and low layer,ground weak and cold air and the torrent in the upper and low latitude.The result of all kinds of physical quantities suggested that the meso-scale rainstorm above the air had distinct characteristics and the heavy precipitation was in the middle Hunan Province.It was caused by meso-system.The dynamic dry belt above the satellite,TBB=-60℃ center and the large value area of the gradient could provide references for the forecast and pre-warning of large rainstorm.[Conclusion] The study accumulated experiences for the forecast and report of rainstorm in Hunan Province. 展开更多
关键词 Large rainstorm Abruptness Characteristics analysis Central hunan province China
下载PDF
Regional Division of Production and Development Strategy of Citrus in Hunan Province
7
作者 杨玉 邓文 +3 位作者 李健权 王卫红 黄国林 张平 《Agricultural Science & Technology》 CAS 2012年第9期2029-2033,共5页
[Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in... [Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in Hunan province were divided into three production regions, namely, superior region, sub-superior and non- superior region. On the base of the divisions, the ecological regionalization and brand strategy, Optimization of regional distribution and developing strategy were proposed, with consideration of avoiding frozen zones, in this paper. [Result] Fresh and processing bases of mandarin orange (C.unshiu Marc), and specialty industries of seedless ponkan(C.reticulata Blanco), Bingtang orange (C.sinensis Osbeck Bing- tangcheng), Dayongjuhuaxinyou (Cgrandis (L.) Osbeck Dayongjuhuaxinyou) and An- jiangxiangyou (C.grandis (L.) Osbeck Anjiangxiangyou) should be constructed, where fresh fruit is dominant, supplemented by canned fruit and juice. Industry belt of sat- suma orange, fresh or processing food, is mainly built, for proportion of early and earlier ripe satsuma orange is over 50% of total yield in Xiangzhong citrus zone; in- dustry belt of excellent fresh navel orange and processing sweet orange should be highlighted in Xiangnan. [Conclusion] The research provides references for decision- making for governments, especially on optimization of citrus production regions and development of citrus industry. 展开更多
关键词 CITRUS Regional division STRATEGY hunan province
下载PDF
Evaluation of Ecological Sustainability Based on Ecological Footprint in Hunan Province
8
作者 曹胜 周卫军 +4 位作者 罗思颖 李娇 黄维丽 段群滔 宋彪 《Agricultural Science & Technology》 CAS 2017年第5期877-879,887,共4页
To make clear ecological sustainable development in Hunan Province, biomass resources and the energy consumption indexes of Hunan Province in 2013 were selected, and quantity analysis of the regional ecological consum... To make clear ecological sustainable development in Hunan Province, biomass resources and the energy consumption indexes of Hunan Province in 2013 were selected, and quantity analysis of the regional ecological consumption and the ecological carrying capacity was carried out using the ecological footprint method. The results showed that the net ecological deficit per capita was 1.718 hm2 in 2013 in Hunan Province, which indicated the regional development was beyond the scope of ecological carrying capacity. So, according to the present unsustainable situation, the corresponding development suggestions were put forward. 展开更多
关键词 Ecological sustainable development Ecological footprint Ecological ca-pacity suggestions hunan province
下载PDF
Production Performance and Development Strategies of Double-cropping Rice in Hunan Province
9
作者 邓文 彭既明 +4 位作者 刘英 祝琪雅 金龙新 刘晗 谭杰扬 《Agricultural Science & Technology》 CAS 2016年第12期2901-2904,共4页
ln the research, an empirical analysis was performed on production per-formance and influential factors of rice in Changsha County and Liling City. The re-sults showed that production scale has been closely linked to ... ln the research, an empirical analysis was performed on production per-formance and influential factors of rice in Changsha County and Liling City. The re-sults showed that production scale has been closely linked to age and education level of farmers. The larger scale, the higher comprehensive performance, but rele-vant efficiency tends to be lower. Sowing area and yield per unit area are major in-fluential factors of production performance of double-cropping rice, but the rest influ-ential factors are different upon production scale. Final y, developmental strategies are proposed for development of double-cropping rice. 展开更多
关键词 Double-cropping rice Mass production performance Development strategies hunan province
下载PDF
Research on the Agglomeration and Fluctuation Situation of Rice Production in Hunan Province
10
作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2011年第10期1405-1410,共6页
[Objective] This paper aimed at studying the agglomeration and fluctuation situation of rice production in Hunan Province during the past 10 years.[Method] Data were collected from Hunan Rural Statistical Yearbook(20... [Objective] This paper aimed at studying the agglomeration and fluctuation situation of rice production in Hunan Province during the past 10 years.[Method] Data were collected from Hunan Rural Statistical Yearbook(2001-2010).Taking the concentration index of sown area and production(CDI) and the volatility index(VI) as the main indicators,the agglomeration and fluctuation situation of paddy rice,early-season rice,middle-season rice and single-season late rice,late-season rice,good quality early-season rice,good quality middle-season rice and good quality single-season late rice,good quality late-season rice production in each major rice-producing area of Hunan Province during the past 10 years had been studied.[Result] The orders of concentration index of sown areas and production of paddy rice,early-season rice,middle-season rice and single-season late rice,late-season rice,good quality early-season rice,good quality middle-season rice and good quality single-season late rice,good quality late-season rice in Hunan Province varied,but the orders of volatility index were consistent.The stable areas,relatively stable areas and fluctuant areas in sown areas and production of different major rice-producing areas were defined.[Conclusion] The research had provided basis for optimizing the layout of rice production in Hunan Province,promoting agglomeration and development of rice production and translating the comparative advantages into the competitive advantages. 展开更多
关键词 RICE AGGLOMERATION FLUCTUATION hunan province
下载PDF
Non-ferrous Metal Industry in Hunan Province
11
《Rare Metals》 SCIE EI CAS CSCD 1993年第1期73-73,共1页
In the last ten years (1982~1991) 2.26 Mt of 10 kinds of nonferrous metals had been pro-duced in Hunan Province. Up to date the mining capacity achieves 6.52 Mt, ore-dressing capacity--7.25 Mt, smelt capacity--334 kt... In the last ten years (1982~1991) 2.26 Mt of 10 kinds of nonferrous metals had been pro-duced in Hunan Province. Up to date the mining capacity achieves 6.52 Mt, ore-dressing capacity--7.25 Mt, smelt capacity--334 kt and the processing capacity--113 kt. In 1991 the output of10 kinds of nonferrous metals amounted to 292.8 kt. At present Hunan Province produces alloys,oxides and other compounds for copper, aluminium, lead, zinc, antimony and mercury. Species ofrare-earth metals and its alloys produced in Hunan Province amount to 160 and more. In this 展开更多
关键词 In Non-ferrous Metal Industry in hunan province
下载PDF
Characteristics of the ore-forming fluid in the Huayuan Pb-Zn ore filed, Northwest of Hunan Province, China
12
作者 WEI Hantao SHAO Yongjun +2 位作者 ZHOU Haodi WANG Cheng XIONG Yiqu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期239-240,共2页
1 Geological Setting The Huayuan Pb-Zn ore field in Xiangxi is located in the southeastern margin of the Yangtze block and the mid-segment of the West Hunan-West Hubei metallogenic belt.The exposed stratum are the lower
关键词 Characteristics of the ore-forming fluid in the Huayuan Pb-Zn ore filed China Northwest of hunan province REE Pb Cl Zn
下载PDF
Ore-Forming Material Sources of the Shizishan Pb-Zn Deposit in Western Hunan Province,China
13
作者 WANG Yunfeng YANG Hongmei +2 位作者 QIU Xiaofei LU Shansong CAI Yingxiong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第5期1929-1930,共2页
Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have ... Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have investigated the geological characteristics,geochemistry and fluid inclusions of this deposit. 展开更多
关键词 PB Ore-Forming Material Sources of the Shizishan Pb-Zn Deposit in Western hunan province China ZN
下载PDF
Study on Agglomeration and Fluctuation Situation and Development Countermeasures of Economic Crop Production in Hunan Province 被引量:1
14
作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2013年第5期797-802,共6页
[Objective] This paper aimed to investigate the agglomeration and fluctuation situation of economic crop production in Hunan Province and to propose related development countermeasures. [Method] With agglomeration ind... [Objective] This paper aimed to investigate the agglomeration and fluctuation situation of economic crop production in Hunan Province and to propose related development countermeasures. [Method] With agglomeration index and fluctuation index as main indicators, the agglomeration and fluctuation situation of the production of seven major economic crops in Hunan Province in recent decade was studied. [Result] The agglomeration index of sown area and yield of seven major economic crops in Hunan Province showed decreasing orders of ramie 〉 cotton 〉 tobacco 〉 rape〉 citrus 〉 tea 〉 vegetables, ramie 〉 cotton 〉 tobacco 〉 tea 〉 rape 〉 citrus 〉 vegetables, respectively; the fluctuation index of sown area and yield showed decreasing orders of ramie 〉 citrus 〉 vegetables 〉 cotton 〉 tea 〉 rape 〉 tobacco, citrus 〉 ramie 〉 tea 〉 cotton 〉 rape 〉 tobacco 〉 vegetables, respectively. In addition, stable regions, relatively stabte regions and fluctuation regions of sown area and yield in various main producing areas were identified, and corresponding development countermeasures were proposed. [Cenclusion] The key to accelerate the development of major economic crop production in Hunan Province is further improving the agglomeration level of vegetable, citrus, rape and tea production and focusing on maintaining the stability of citrus, ramie and cotton production in main producing areas. 展开更多
关键词 Economic crop AGGLOMERATION FLUCTUATION Development countermeasures hunan province
下载PDF
Huaihua,a Growing Part of Hunan Province
15
作者 XU XIAOYAN 《China Today》 1995年第10期26-29,共4页
Huaihua,aGrowingPartofHunanProvinceAprefecturemovesaheadbygivingitslandbacktonature.BystaffreporterXUXIAOYAN... Huaihua,aGrowingPartofHunanProvinceAprefecturemovesaheadbygivingitslandbacktonature.BystaffreporterXUXIAOYANLYINGINsouthweste... 展开更多
关键词 Huaihua a Growing Part of hunan province
下载PDF
Study on the fractionation of inorganic phosphates in some paddy soils of Hunan Province
16
《Chinese Rice Research Newsletter》 1999年第2期8-9,共2页
Hunan Province of China,lying in the centralof subtropical zone,is one of the major pro-duction areas of double-season rice.Rice pad-dy is the main agricultural soil of the area.Mixed samples of plough horizon(0-20cm... Hunan Province of China,lying in the centralof subtropical zone,is one of the major pro-duction areas of double-season rice.Rice pad-dy is the main agricultural soil of the area.Mixed samples of plough horizon(0-20cm)ofmajor types of paddy soils were collected be- fore cultivation in the spring of 1996-1997.The chemical fractions of inorganic phosphatesand the relationships between inorganic phos- phates and olsen-available P in the soils werestudied by using the fractionation system of in-organic phosphates proposed by JIANG Baifanet al. 展开更多
关键词 Study on the fractionation of inorganic phosphates in some paddy soils of hunan province
下载PDF
Fixed Ammonium in Major Types of Paddy Soils in Hunan Province, China 被引量:11
17
作者 ZHANG YANGZHU, LIAO JIPEI, SUN YUHUAN, FENG YUEHUA and HUANG YUNXIANGCollege of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China) 《Pedosphere》 SCIE CAS CSCD 2003年第3期199-208,共10页
The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner ... The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil > alluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type. 展开更多
关键词 affecting factors BIOAVAILABILITY fixed ammonium hunan province paddysoil
下载PDF
Characteristics of Shale Reservoir and Sweet Spot Identification of the Lower Cambrian Niutitang Formation in Northwestern Hunan Province, China 被引量:4
18
作者 QIN Mingyang CAO Zheng +3 位作者 GUO Jianhua HUANG Yanran SUN Lianpu DONG Li 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第3期573-587,共15页
The accumulation and productivity of shale gas are mainly controlled by the characteristics of shale reservoirs;study of these characteristics forms the basis for the shale gas exploitation of the Lower Cambrian Niuti... The accumulation and productivity of shale gas are mainly controlled by the characteristics of shale reservoirs;study of these characteristics forms the basis for the shale gas exploitation of the Lower Cambrian Niutitang Formation(Fm),Southern China.In this study,core observation and lithology study were conducted along with X-ray diffraction(XRD)and electronic scanning microscopy(SEM)examinations and liquid nitrogen(N2)adsorption/desorption and CH4 isothermal adsorption experiments for several exploration wells in northwestern Hunan Province,China.The results show that one or two intervals with high-quality source rocks(TOC>2 wt%)were deposited in the deep-shelf facies.The source rocks,which were mainly composed of carbonaceous shales and siliceous shales,had high quartz contents(>40 wt%)and low clay mineral(<30 wt%,mainly illites)and carbonate mineral(<20 wt%)contents.The SEM observations and liquid nitrogen(N2)adsorption/desorption experiments showed that the shale is tight,and nanoscale pores and microscale fractures are well developed.BJH volume(VBJH)of shale ranged from 2.144×10^-3 to 20.07×10^-3 cm^3/g,with an average of 11.752×10^-3 cm3/g.Pores mainly consisted of opened and interconnected mesopores(2–50 nm in diameter)or macropores(>50 nm in diameter).The shale reservoir has strong adsorption capacity for CH4.The Langmuir volume(VL)varied from 1.63 to 7.39 cm^3/g,with an average of 3.95 cm^3/g.The characteristics of shale reservoir are controlled by several factors:(1)A deep muddy continental shelf is the most favorable environment for the development of shale reservoirs,which is controlled by the development of basic materials.(2)The storage capacity of the shale reservoir is positively related to the TOC contents and plastic minerals and negatively related to cement minerals.(3)High maturity or overmaturity leads to the growth of organic pores and microfractures,thereby improving the reservoir storage capacity.It can be deduced that the high percentage of residual gas in Niutitang Fm results from the strong reservoir storage capacity of adsorbed gas.Two layers of sweet spots with strong storage capacity of free gas,and they are characterized by the relatively high TOC contents ranging from 4 wt%to 8 wt%. 展开更多
关键词 NORTHWESTERN hunan province Niutitang Formation RESERVOIR CHARACTERISTICS control factors sweet SPOTS IDENTIFICATION
下载PDF
Fixed Ammonium Content and Maximum Capacity of Ammonium Fixation in Major Types of Tillage Soils in Hunan Province,China 被引量:5
19
作者 ZHANG Yang-zhu HUANG Shun-hong +3 位作者 WAN Da-juan HUANG Yun-xiang ZHOU Wei-jun ZOU Ying-bin 《Agricultural Sciences in China》 CAS CSCD 2007年第4期466-474,共9页
In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied ... In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows: (1) Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32,4 mg kg^-1, with 304.7±96.7 mg kg^-1 in average; while it ranges from 59.4 to 435.7 mg kg^-1, with 230.1 ± 89.2 mg kg^-1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ±3.6% to 16.6±4.6%, with 14.0% ±5.1% in average for the paddy soils and it amounted to 5.8±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. (2) The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. (3) The clay content and clay composition in the tested soils are the two important factors influencing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2:1 type clay mineral in 〈 0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in 〈 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with the total 2:1 type clay mineral content and hydrous mica content in 〈 0.02 mm clay and 0,02-0.002 mm clay at the significant level of P0.01 or P0.05, respectively, but not correlated with the total 2:1 type clay mineral content and hydrous mica content in 〈0.002 mm clay significantly, It demonstrated that the ammonium-fixing matrix of the tested soils mainly exists in the 0.02-0.002 mm clay. The above-mentioned results showed that fixed ammonium is a major form of N in the tillage soils in Hunan Province, China. It would play an important role in N nutrition of crops, especially for upland crops, and deserve to be further researched. 展开更多
关键词 hunan province tillage soils paddy soil upland soil fixed ammonium maximum capacity of ammonium fixation
下载PDF
Estimating health damage cost from secondary sulfate particles—a case study of Hunan Province,China 被引量:3
20
作者 HAO Ji ming, LI Ji, YE Xue mei, ZHU Tian le (Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. ) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第5期611-617,共7页
China's coal dominated energy pattern has resulted in large amount of SO 2 emissions. Estimate of the sulfur related health damage cost is necessary to help perform systematic cost benefit analysis and set nat... China's coal dominated energy pattern has resulted in large amount of SO 2 emissions. Estimate of the sulfur related health damage cost is necessary to help perform systematic cost benefit analysis and set national energy and emissions control priorities. Current researches were confined to gaseous SO 2 in urban areas; however, secondary sulfate (SO 2- 4) particles can exert serious impact in a wider region. Based on the concept of “intake fraction', CALPUFF long range dispersion model and 180 sample emission sources, multiple regression equation was obtained with good correlation( r =0 85), which illustrates that populations were key parameters to determine intake fraction but source characteristics were insignificant. Based on the formula and the population distribution data, county level intake fractions were mapped for Hunan Province(range: 1 1×10 -6 -3 2×10 -6 ) of China. A combination of county level SO 2 emissions with the intake fractions yields a total 1 98 tons of sulfate(SO 2- 4) inhalation, and resulting total health damage cost to be 0 76(willingness to pay approach, WTP) or 0 16(human capital approach, HC) billion USD in 1997, about 2.1% or 0 45% of GDP in Hunan in 1997. Average health damage cost per ton of SO 2 emission is 930(WTP) or 200 USD(HC). The results demonstrated that more stringent regulation should be forced. 展开更多
关键词 intake fraction health impact hunan province SULFATE regression analysis
下载PDF
上一页 1 2 228 下一页 到第
使用帮助 返回顶部