期刊文献+
共找到48篇文章
< 1 2 3 >
每页显示 20 50 100
Integrity and Size of Green Spaces Are Critical for the Functional Di-versity of Birds:Evidence from the Eastern and Northwestern Regions of China
1
作者 GONG Lingxuan WANG Lili +5 位作者 YAO Yao WU Linyi WANG Su TAN Bingchang YUAN Hongdan HU Runan 《Chinese Geographical Science》 SCIE CSCD 2024年第6期1073-1089,共17页
Urbanization often changes bird species richness and affects the functional diversity.Therefore,understanding these changes helps city planners improve green space design and land use planning.Our study used multiple ... Urbanization often changes bird species richness and affects the functional diversity.Therefore,understanding these changes helps city planners improve green space design and land use planning.Our study used multiple datasets to explore the effects of land-scape patterns and natural environments on the functional diversity of birds in urban parks and campuses in the eastern and northwest-ern regions of China.Firstly,we used the data to calculate birds of the functional richness(FRic),functional evenness(FEve),and func-tional divergence(FDiv)of 68 urban spaces in the eastern and northwestern regions of China.Further,we established generalized linear models of natural factors,human factors,and functional diversity.Results showed more bird species with unique traits were in the north-western region.This may be because the earlier urbanization in the eastern region filtered out urban-sensitive species,leaving behind urban adapters.Moreover,we found that the fractal dimension index was the most significant positive factor of FRic in the eastern re-gion but the most significant negative factor of FDiv.Elevation was the most significant negative influence factor of FEve in the eastern region,but it was the most potent positive influence factor of FRic in the northwestern region.Population density had a significant posit-ive effect on FDiv in the northwestern region.However,green space areas significantly negatively impacted FEve in the northwestern region.In addition,birds in parks in both regions had more functional traits than those on campuses,possibly because of the larger green space in parks,which may contain more fragments of native vegetation and reduce human interference.Our study suggests that pre-serving more original vegetation and reducing human disturbance in cities can increase the functional diversity of urban birds and im-prove urban ecosystem functions. 展开更多
关键词 BIRDS functional diversity green space the eastern and northwestern regions of China
下载PDF
Contribution of algae and bacteria during humic coal formation in the Taiyuan Formation in the eastern part of North China
2
作者 王飞宇 《Chinese Science Bulletin》 SCIE EI CAS 1995年第7期615-616,共2页
The significant differences in properties of humic coal from the Carboniferous TaiyuanFormation and from the Permian Shanxi Formation in North China have acquired a spe-cial interest in recent years. The abnormalities... The significant differences in properties of humic coal from the Carboniferous TaiyuanFormation and from the Permian Shanxi Formation in North China have acquired a spe-cial interest in recent years. The abnormalities of humic coal from the Taiyuan 展开更多
关键词 Contribution of algae and bacteria during humic coal formation in the Taiyuan Formation in the eastern part of North China
原文传递
Spatio-temporal analysis of land-use conversion in the eastern coastal China during 1996-2005 被引量:95
3
作者 LIU Yansui WANG Lijuan LONG Hualou 《Journal of Geographical Sciences》 SCIE CSCD 2008年第3期274-282,共9页
Based on the acquaintance of the regional background of urban-rural transformational development and investigations on the spot,this paper discusses the holistic situation, dominant factors and mechanism of arable lan... Based on the acquaintance of the regional background of urban-rural transformational development and investigations on the spot,this paper discusses the holistic situation, dominant factors and mechanism of arable land loss and land for construction occupation in the coastal area of China over the last decade,with the aid of GIS technology.Conclusions of the research are summarized as follows:(1)the arable land had been continuously decreasing from 1996 to 2005,with a loss of 1,708,700 hm^2 and an average decrement of 170,900 hm^2 per year;(2)land for construction increased 1,373,700 hm^2 ,with an average increment of 153,200 hm^2 per year;(3)total area of encroachment on arable land for construction between 1996 and 2005 was 1,053,100 hm^2 ,accounting for 34.03%of the arable land loss in the same period,the percentages of which used for industrial land(INL),transportation land(TRL),rural construction land(RUL)and town construction land(TOL)are 45.03%,15.8%,15.47%and 11.5%,respectively;and(4)the fluctuation of the increase of construction land and encroachment on arable land in the area were deeply influenced by the nation's macroscopic land-use policies and development level of regional economy.The growth of population and advancement of technology promoted the rapid industrialization, construction of transportation infrastructures,rural urbanization and expansion of rural settlements in the eastern coastal area,and therefore were the primary driving forces of land-use conversion. 展开更多
关键词 urban-rural harmonious development rural urbanization new countryside construction arable land loss the eastern coastal China
下载PDF
Appraisal of typical rural development models during rapid urbanization in the eastern coastal region of China 被引量:10
4
作者 刘彦随 张富刚 张潆文 《Journal of Geographical Sciences》 SCIE CSCD 2009年第5期557-567,共11页
The sustainability of regional rural development depends on the integrated status and the coordination between rural resources-environment conditions and rural socioeco- nomic development. In this paper a diagnostic i... The sustainability of regional rural development depends on the integrated status and the coordination between rural resources-environment conditions and rural socioeco- nomic development. In this paper a diagnostic indicator system is proposed to appraise four representative rural development models such as Mentougou model, Taicang model, Yueqing model and Qionghai model in the eastern coastal region of China from the integrated perspective of population, resources, environment, and development. In conclusion, the formation and evolution of these diverse rural deveJopment models are the direct response to the very different characteristics in the environment, market demand, and regional culture. These models are common in that their sustainability depends on the scientific guidance of the regional development functional positioning, strong intra-regional interactions, and self-adaptability to the external conditions. 展开更多
关键词 rural development model URBANIZATION coordinated development degree the eastern coastal China
下载PDF
Petrogenesis of the~2115 Ma Haicheng Mafic Sills in the Eastern North China Craton and Their Implications for An Intra-Continental Rifting 被引量:30
5
作者 WANG Xinping PENG Peng +1 位作者 WANG Chong YANG Shuyan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期128-,共1页
It is well known that there are widespread igneous events at;100 Ma in the Eastern North China Craton;however,their tectonic environments are controversial.They were thought to be either related to an intra-continenta... It is well known that there are widespread igneous events at;100 Ma in the Eastern North China Craton;however,their tectonic environments are controversial.They were thought to be either related to an intra-continental rifting or 展开更多
关键词 Ma Haicheng Mafic Sills in the eastern North China Craton and their Implications for An Intra-Continental Rifting Petrogenesis of the
下载PDF
Gravity observations along the eastern margin of the Tibetan Plateau and an application to the Lushan MS 7.0 earthquake 被引量:8
6
作者 Wei-feng Liang Yun-feng Zhao +4 位作者 Yun-ma Xu Yi-qing Zhu Shu-song Guo Fang Liu Lian Liu 《Earthquake Science》 2013年第3期251-257,共7页
This paper introduces relative and absolute gravity change observations in the eastern portion of the Tibetan Plateau. We analyze and discuss a change that occurred in 2010 in the gravity along the eastern margin of t... This paper introduces relative and absolute gravity change observations in the eastern portion of the Tibetan Plateau. We analyze and discuss a change that occurred in 2010 in the gravity along the eastern margin of the plateau and the relationship between this change and the 2013 Lushan Ms7.0 earthquake. Our results show that: (1) before the Lushan MsT.0 earthquake, gravity anomalies along the eastern margin of the Tibetan Plateau changed drastically. The Lushan earthquake occurred at the bend of the high gradient zone of gravity var- iation along the southern edge of the Longmenshan fault zone. (2) The 2013 Lushan earthquake occurred less than 100 km away from the epicenter of the 2008 Wenchuan earthquake. Lushan and Wenchuan are located at the center of a four- quadrant section with different gravity anomalies, which may suggest that restoration after the Wenchuan earthquake may have played a role in causing the Lushan earthquake. (3) A medium-term prediction based on changes in gravity anoma- lies was made before the Lushan Ms7.0 earthquake, in par- ticular, a prediction of epicenter location. 展开更多
关键词 the eastern margin of the TibetanPlateau Gravity observation Gravity changeLushan earthquake Medium-term prediction
下载PDF
Estimation of Seismic Landslide Hazard in the Eastern Himalayan Syntaxis Region of Tibetan Plateau 被引量:5
7
作者 DU Guoliang ZHANG Yongshuang +5 位作者 YANG Zhihua Javed IQBAL TONG Bin GUO Changbao YAO Xin WU Ruian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第2期658-668,共11页
The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning an... The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning and construction of Sichuan-Tibet highway, Sichuan-Tibet railway and hydropower development on the Yarlung Zangbo River etc. in recent years, it is very important to evaluate the seismic landslide hazard of this region. In this paper, a seismic landslide hazard map is produced based on seismic geological background analysis and field investigation using Newmark method with 10% PGA exceedance probabilities in future 50 years by considering the influence of river erosion, active faults and seismic amplification for the first time. The results show that the areas prone to seismic landslides are distributed on steep slopes along the drainages and the glacier horns as well as ridges on the mountains. The seismic landslide hazard map produced in this study not only predicts the most prone seismic landslide areas in the future 50 years but also provides a reference for mitigation strategies to reduce the exposure of the new building and planning projects to seismic landslides. 展开更多
关键词 probabilistic seismic hazard Newmark method seismic landslide the eastern Himalayan syntaxis TIBET Proto-Tethys
下载PDF
Origin, Age and Significance of Pseudotachylites from the Eastern Dabieshan Orogenic Belt, China 被引量:4
8
作者 LIUJianmin DONGShuwen +2 位作者 ZHANGJiasheng LIUXiaochun CHENBailin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期52-60,共9页
Recent field survey in the eastern Dabieshan Mountains has revealed extensive occurrences of pseudotachylite. The pseudotachylite tends to occur as simple veins and injected networks along the NE-SW-trending fracture ... Recent field survey in the eastern Dabieshan Mountains has revealed extensive occurrences of pseudotachylite. The pseudotachylite tends to occur as simple veins and injected networks along the NE-SW-trending fracture zones or shear zones, which are parallel to the Tanlu fault zone and cut all the pre-Cretaceous geological bodies. The characteristics of both the microstructures gained by the optical microscope and SEM imaging and the geochemistry between the pseudotachylites and their host rocks show that the pseudotachylites were formed mainly by ultracataclasis of their wall rocks in which they occur. The bulk K-Ar ages of the pseudotachylites yielded a narrow range of 81 -93 Ma, and moreover the laser-probe 40Ar/39Ar dating of phengite overprinting on the pseudotachylite gave a weighted mean age of 78.9 Ma. These results show that the pseudotachylites from the eastern Dabieshan Mountains formed along the NE-SW-trending fault zone during the uplifting of the orogenic belt at 80-90 Ma, which places important constrains on the cooling and exhumation history of the Dabieshan Mountains during and after the late Cretaceous. 展开更多
关键词 PSEUDOTACHYLITE ORIGIN microstructure geochemistry age the eastern Dabieshan Mountains
下载PDF
Characteristics of highly differentiated granite and metallization of tungsten-tin, rare and rare earth metal in the eastern Nanling region, China 被引量:6
9
作者 XIAO Huiliang CHEN Lezhu +5 位作者 FAN Feipeng LI Haili BAO Xiaoming YAO Zhenghong ZHOU Yan CAI Yitao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期100-101,共2页
1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate th... 1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate that the Yanshanian highly differentiated-granite formation is closely related to the deposits of tungsten and tin,rare and rare earth metals mineralization in the region(Xiao 展开更多
关键词 Th high rare and rare earth metal in the eastern Nanling region Characteristics of highly differentiated granite and metallization of tungsten-tin China
下载PDF
New Evidence of Detrital Zircon Ages for the Final Closure Time of the Paleo-Asian Ocean in the Eastern Central Asian Orogenic Belt(NE China) 被引量:4
10
作者 DU Qingxiang HAN Zuozhen +6 位作者 SHEN Xiaoli HAN Chao SONG Zhigang GAO Lihua HAN Mei ZHONG Wenjian YAN Junlei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第5期1910-1914,共5页
Objective The NE China is located in the eastern segment of the Central Asian Orogenic Belt(CAOB),which is a large accretionary orogen between the Siberian Craton and the North China Craton(NCC).Many researches ha... Objective The NE China is located in the eastern segment of the Central Asian Orogenic Belt(CAOB),which is a large accretionary orogen between the Siberian Craton and the North China Craton(NCC).Many researches have discussed about the evolution of the Paleo-Asian Ocean(PAO)in the eastern CAOB.However, 展开更多
关键词 Th NE China New Evidence of Detrital Zircon Ages for the Final Closure Time of the Paleo-Asian Ocean in the eastern Central Asian Orogenic Belt OHS NCC Pb
下载PDF
Subsidence History of the Eastern Depression in the North Yellow Sea Basin 被引量:5
11
作者 CAO Dai-yong WANG Xin-guo +1 位作者 ZHAN Wen-feng LI Wen-yong 《Journal of China University of Mining and Technology》 EI 2007年第1期90-95,共6页
Using a back-stripping method, our paper simulated the subsidence history of the eastern depression in the North Yellow Sea Basin. The subsidence history curve pattern and the subsidence chorisogram during every subsi... Using a back-stripping method, our paper simulated the subsidence history of the eastern depression in the North Yellow Sea Basin. The subsidence history curve pattern and the subsidence chorisogram during every subsiding period were exposed. Combining with the regional geologic background and the distribution features of the subsiding centers in every period, a contrasting study of the pattern and the classical subsidence history curves shows the subsi- dence history is made up of Mesozoic (J3-K1) and Cenozoic (E2-Q) subsiding cycles. The two subsiding cycles are separated by the late Cretaceous and Paleocene (K2-E1) uplift denudation. Both subsiding cycles have the characteristics of an extension basin. The rapid subsidence during the late Jurassic and Eocene is equivalent to the initial subsiding phases in both cycles.. The slow subsidence of both, the early Cretaceous and Neogene, can be regarded as thermal sub-sidence phases . 展开更多
关键词 the eastern depression subsidence history extension basin back-stripping method
下载PDF
Crustal Uplift in the Longmen Shan Mountains Revealed by Isostatic Gravity Anomalies along the Eastern Margin of the Tibetan Plateau 被引量:3
12
作者 LI Yong YAN Zhaokun +4 位作者 ZHOU Rongjun YAN Liang DONG Shunli SHAO Chongjian Svirchev LAURENCE 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第1期56-73,共18页
This study examines the relationship between high positive isostatic gravity anomalies (IGA), steep topography and lower crustal extrusion at the eastern margin of the Tibetan Plateau. IGA data has revealed uplift a... This study examines the relationship between high positive isostatic gravity anomalies (IGA), steep topography and lower crustal extrusion at the eastern margin of the Tibetan Plateau. IGA data has revealed uplift and extrusion of lower crustal flow in the Longmen Shan Mountains (the LMS). Firstly, The high positive IGA zone corresponds to the LMS orogenic belt. It is shown that abrupt changes in IGA correspond to zones of abrupt change of topography, crustal thickness and rock density along the LMS. Secondly, on the basis of the Airy isostasy theory, simulations and inversions of the positive IGA were conducted using three-dimensional bodies. The results indicated that the LMS lacks a mountain root, and that the top surface of the lower crust has been elevated by 11 km, leading to positive IGA, tectonic load and density load. Thirdly, according to Watts's flexural isostasy model, elastic deflection occurs, suggesting that the limited (i.e. narrow) tectonic and density load driven by lower crustal flow in the LMS have led to asymmetric flexural subsidence in the foreland basin and lifting of the forebulge. Finally, based on the correspondence between zones of extremely high positive IGA and the presence of the Precambrian Pengguan-Baoxing complexes in the LMS, the first appearance of erosion gravels from the complexes in the Dayi Conglomerate layer of the Chengdu Basin suggest that positive IGA and lower crustal flow in the LMS took place at 3.6 Ma or slightly earlier. 展开更多
关键词 isostatic gravity anomalies crustal uplift Longmen Shan Mountains lower crustal flow foreland basin the eastern margin of the Tibetan Plateau
下载PDF
Magnetostratigraphy of a Loess-Paleosol Sequence from Higher Terrace of the Daduhe River in the Eastern Margin of the Tibetan Plateau and Its Geological Significance 被引量:6
13
作者 QIAO Yansong WANG Yan +5 位作者 YAO Haitao QI Lin HE Ze Xin CHENG Yu PENG Shasha GE Junyi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第1期316-317,共2页
The eolian deposits distributed in the river valleys in the eastern margin of the Tibetan Plateau (TP) are very useful in neotectonic and paleoclimatic studies. Firstly, the climate in the eastern margin of the TP i... The eolian deposits distributed in the river valleys in the eastern margin of the Tibetan Plateau (TP) are very useful in neotectonic and paleoclimatic studies. Firstly, the climate in the eastern margin of the TP is mainly controlled by the Indian summer monsoon, and detailed studies on the loess-paleosol sequences in this region can provide valuable terrestrial evidence of past changes in the Indian summer monsoon. Secondly, the river terraces in the eastern margin of the TP are considered to be a sensitive recorder of neotectonism to reflect the timing and amplitude of the TP uplift. 展开更多
关键词 In Magnetostratigraphy of a Loess-Paleosol Sequence from Higher Terrace of the Daduhe River in the eastern Margin of the Tibetan Plateau and Its Geological Significance
下载PDF
New Zircon U-Pb Age of the Ore-bearing Porphyry from the Kuga Copper Deposit in the Eastern Bangongco–Nujiang Matallogenic Belt, Tibet 被引量:3
14
作者 LIN Bin SONG Yang +2 位作者 LIU Zhibo LIU Zhenyu GAO Yiming 《Acta Geologica Sinica(English Edition)》 CAS CSCD 2018年第2期859-861,共3页
Objective As the third most important copper polymetallic metallogenic belt in Tibet, the Bangongco-Nujiang metallogenic belt (BNMB) has attracted much attention among geoscientists all over the world (Lin Bin et ... Objective As the third most important copper polymetallic metallogenic belt in Tibet, the Bangongco-Nujiang metallogenic belt (BNMB) has attracted much attention among geoscientists all over the world (Lin Bin et al., 2017a). There are two ore clusters in the westem of BNMB, the Duolong giant porphyry-epitherrnal Cu (Au, Ag) ore cluster and the Ga'erqiong-Galalelarge porphyry- skarn Cu (Au) ore cluster (Lin Bin et al., 2017a; 2017b). Now, the latest exploration advances show that the Kuga project is the first economic porphyry-skam copper deposit in the eastern of BNMB, with over 0.4 Mt melt copper (333+334) @ 0.9%. However, the Kuga deposit is poorly studied about its diagenetic age. In this study, we present a zircon U-Pb LA-ICP-MS dating of ore-bearing biotite granite, in order to identify the time of the ore- related magmatism and reveal the relationship with the westem of BNMB. 展开更多
关键词 PB TIBET Nujiang Matallogenic Belt New Zircon U-Pb Age of the Ore-bearing Porphyry from the Kuga Copper Deposit in the eastern Bangongco
下载PDF
Application of the Material Balance Method in Paleoelevation Recovery: A Case Study of the Longmen Mountains Foreland Basin on the Eastern Margin of the Tibetan Plateau 被引量:4
15
作者 YAN Zhaokun LI Yong +6 位作者 LI Haibing DONG Shunli ZHAO Guohua LI Jingbo LI Fensheng YAN Liang ZHENG Lilong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第2期598-609,共12页
We applied the material balance principle of the denudation volume and sedimentary flux to study the denudation-accumulation system between the Longmen Mountains (Mts.) and the foreland basin. The amount of sediment... We applied the material balance principle of the denudation volume and sedimentary flux to study the denudation-accumulation system between the Longmen Mountains (Mts.) and the foreland basin. The amount of sediment in each sedimentation stage of the basin was estimated to obtain the denudation volume, erosion thickness and deposit thickness since the Late Triassic Epoch, to enable us to recover the paleoelevation of the provenance and the sedimentary area. The results show the following: (1) Since the Late Triassic Epoch, the elevation of the surface of the Longmen Mts. has uplifted from 0 m to 2751 m, and the crust of the Longmen Mts. has uplifted by 9.8 km. Approximately 72% of the materials introduced have been denuded from the mountains. (2) It is difficult to recover the paleoelevation of each stage of the Longmen Mts. foreland basin quantitatively by the present-day techniques and data. (3) The formation of the Longmen Mts. foreland basin consisted of three stages of thrust belt tectonic load and three stages of thrust belt erosional unload. During tectonic loading stages (Late Triassic Epoch, Late Jurassic-Early Cretaceous, Late Cretaceous-Miocene), the average elevation of Longmen Mts. was lower (approximately 700-1700 m). During erosional unloading stages (Early and Middle Jurassic, Middle Cretaceous and Jiaguan, Late Cenozoic), the average elevation of Longmen Mts. was high at approximately 2000-2800m. 展开更多
关键词 Longmen Mountains foreland basin material balance method paleoelevation recovery the eastern margin of the Tibetan Plateau
下载PDF
Climate change and permafrost stability in the eastern Canada Cordillera:The results of 33 years of measurements 被引量:3
16
作者 Stuart A.Harris 《Research in Cold and Arid Regions》 2009年第5期381-403,共23页
Over the last 33 years,a network of climate stations has been set up at high altitude mountain permafrost sites from Plateau Mountain near Claresholm,Alberta,north to Sheldon Lake on the North Canol Road in the Yukon.... Over the last 33 years,a network of climate stations has been set up at high altitude mountain permafrost sites from Plateau Mountain near Claresholm,Alberta,north to Sheldon Lake on the North Canol Road in the Yukon.Taken together with the data from the US National Weather Service and the Canadian Atmospheric Environment Service,the results indicate a cooling of mean annual air temperature south of Calgary,no significant change in Calgary,a slight warming at Jasper,and a major warming at Summit Lake,west of Fort Nelson.In contrast,the south eastern and central Yukon show only a minor warming trend that lies well within the limits of a sixty-year record measured by the Canadian Atmospheric Environment Service.Along the Mackenzie valley and on the North Slope of Alaska,the mean annual air temperature is rising.Permafrost is aggrading on Plateau Mountain,degrading at Summit Lake,and appears to be stable in southern Yukon and southern Alaska.This is in contrast to the warming occurring on the Arctic coastal plain and along the Mackenzie valley.It therefore appears that changes in climate vary considera-bly from place to place,and even where warming may occur,it may not continue indefinitely.There has been a northward shift of the arctic front due to a weakening of air pressure in the Yukon and Alaska relative to the continental tropical(cT) and maritime polar(mT) air masses to the south.Any actual changes that may be occurring appear to undergo amplification along the Mackenzie valley and Arctic coastal plain and reduction by buffering in the interior Yukon and Alaskan mountains,a result of mi-cro-environmental factors.Continued,careful monitoring of the climate is required and needs to be expanded in the National Parks in the mountains in order to provide data on the changes that may be taking place.Such measurements can provide a sound basis for interpreting ecological and other climate-related data.The existing climate models are not working satisfactorily because we do not know enough about the causes and processes involved in climate change.Improved results can indicate where best to site structures such as pipelines so as to minimize maintenance costs.Models may also help explain why certain areas such as Beringia,which saw reduced climate change,acted as important refugia during the glaciations. 展开更多
关键词 PERMAFROST STABILITY long-term measurement climate change the eastern Canada Cordillera
下载PDF
Distribution of chlorophyU a and estimation of primary productivity in the eastern waters of Balingtang Channel in summer 被引量:1
17
作者 Huang Liangmin and Chen QingchaoSouth China Sea Institute of Oceaiutlogy, Academia Sinica, Guangzhou, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第4期605-606,共2页
Oceanographical features on both sides of Balingtang Channel (17°55′-20°06′N, 122°55′-126°57′E) were comprehensively investigated on board of R/V "Experiment 3" in June. 1984. The pre... Oceanographical features on both sides of Balingtang Channel (17°55′-20°06′N, 122°55′-126°57′E) were comprehensively investigated on board of R/V "Experiment 3" in June. 1984. The pre-sent paper reports the chlorophyll data collected and primary productivity estimated there. Water sam-ples were taken with a glass bottle of Model HQMat the depth of 0, 10. 25, 50, 75, 100 and 150m, separately. Chlorophyll was determined according to the spectrophotometry proposed by UNESCO(1966) and calculated with the trichromatic equations of Jeffrey-Humphrey(1975). Estimations ofprimary productivity were carried out using a simplified equation (Q = 1.5) given by Cadee(1975). 展开更多
关键词 Distribution of chlorophyU a and estimation of primary productivity in the eastern waters of Balingtang Channel in summer
下载PDF
Non-destructive γ spectrum analysis of polymetallic nodules from the eastern Pacific
18
作者 刘广山 黄奕普 +1 位作者 蔡毅华 陈敏 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2002年第3期373-384,共12页
Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacificwere carried out. Numerous nuclides, such as 238U,230Th,226Ra,210Pb,228Ra,228Th,235U,227Ac (or 231 Pa) and 40K were detected. The... Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacificwere carried out. Numerous nuclides, such as 238U,230Th,226Ra,210Pb,228Ra,228Th,235U,227Ac (or 231 Pa) and 40K were detected. The count rates of the nuclides in the top or bottom side of nodules facing detector were measured and the ratio R of the count rates of nuclides in the top and the bottom sides was obtained. From counts and ratios, some useful information relating to the growth and movement of the nodules, the source of nuclide and relationship between those and environment can be gotten. A new method for clear distinction between the top and bottom sides of the nodule based on the R value of 226Ra or 210Pb was developed. In addition, one can infer the turnover of nodules according to the R value of 230Th. 展开更多
关键词 the eastern Pacific polymetallic nodule RADIONUCLIDE γ-spectrometry
下载PDF
Pressure-temperature Evolution of the Metapelites in the Motuo Area, the Eastern Himalayan Syntaxis
19
作者 DONG Hanwen XU Zhiqin +1 位作者 LI Yuan LIU Zhao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第2期544-557,共14页
The Motuo area is located in the east of the Eastern Himalayan Syntaxis.There outcrops a sequence of high-grade metamorphic rocks,such as metapelites.Petrology and mineralogy data suggest that these rocks have experie... The Motuo area is located in the east of the Eastern Himalayan Syntaxis.There outcrops a sequence of high-grade metamorphic rocks,such as metapelites.Petrology and mineralogy data suggest that these rocks have experienced three stages of metamorphism.The prograde metamorphic mineral assemblages (M1) are mineral inclusions (biotite + plagioclase + quartz ± sillimanite ± Fe-Ti oxides) preserved in garnet porphyroblasts,and the peak metamorphic assemblages (M2) are represented by garnet with the lowest Xsps values and the lowest XFe# ratios and the matrix minerals (plagioclase + quartz ± K-feldspar + biotite + muscovite + kyanite ± siilimanite),whereas the retrograde assemblages (M3) are composed of biotite + plagioclase + quartz symplectites rimming the garnet porphyroblasts.Thermobarometric computation shows that the metamorphic conditions are 562-714℃ at 7.3-7.4 kbar for the M1 stage,661-800℃ at 9.4-11.6 kbar for the M2 stage,and 579-713℃ at 5.5-6.6 kbar for the M3 stage.These rocks are deciphered to have undergone metamorphism characterized by clockwise P-T paths involving nearly isothermal decompression (ITD) segments,which is inferred to be related to the collision of the India and Eurasia plates. 展开更多
关键词 metamorphic rocks P-T path Motuo area the eastern Himalayan Syntaxis
下载PDF
Minto Large Igneous Province: A 2.00 Ga Mafic Magmatic Event in the Eastern Superior Craton Based on U-Pb Baddeleyite Geochronology and Paleomagnetism
20
作者 Michael A.HAMILTON Jean GOUTIER Kenneth L.BUCHAN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期69-70,共2页
A precise U-Pb baddeleyite age of 1999±2 Ma has been obtained for the NNW trending Lac Shpogan dyke swarm of the James Bay area of the eastern Superior craton.Previously the age of the swarm was only
关键词 Pb A 2.00 Ga Mafic Magmatic Event in the eastern Superior Craton Based on U-Pb Baddeleyite Geochronology and Paleomagnetism Minto Large Igneous Province Bay GA
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部