期刊文献+
共找到1,071篇文章
< 1 2 54 >
每页显示 20 50 100
Temporal Variability of Tropospheric NO_(2)over Cities in the United States,Western Europe and China from 2005 to 2022
1
作者 ZHANG Qianqian 《Chinese Geographical Science》 SCIE CSCD 2024年第6期983-992,共10页
Anthropogenic Nitrogen oxides(NO_(x)=NO_(2)+NO)emissions are highly concentrated in urban area,and the weekly cycles,seasonal patterns and long-term trends of tropospheric NO_(2)columns over cities differ from region ... Anthropogenic Nitrogen oxides(NO_(x)=NO_(2)+NO)emissions are highly concentrated in urban area,and the weekly cycles,seasonal patterns and long-term trends of tropospheric NO_(2)columns over cities differ from region to region due to different emission sectoral compositions and human activities.In this study,we used satellite observed tropospheric NO_(2)column data to compare the longand short-term NO_(2)column density time series over cities in the United Sates(the U.S.),western Europe and China.The results showed that in all the targeted cities,the outbreak of the Corona Virus Disease in 2019(COVID-19)moved the December peak of the city-level NO_(2)columns forward to November and October or even earlier in 2020 and 2021.On weekly level,cities in the U.S.show the lowest NO_(2)columns ratio on weekend/work day,then come the western European cities,and a weak weekly pattern is seen in Chinese cities.For all the cites,we find a higher weekend/work day NO_(2)ratio in cold seasons than in warm seasons,indicating a higher contribution from NOx emission sectors of residential,industry and power plants in the warm seasons.In the long-term,NO_(2)columns over the U.S.and western European cities declined by a fraction twice that of the regional mean level from 2004 to 2021.In China,NO_(2)columns started to decrease since 2012,at a similar rate between the city and regional level.This work confirms the importance to quantify and control NOx emissions from cities. 展开更多
关键词 NO_(2)columns urban region weekly cycle seasonal pattern long-term trend united States western Europe China
下载PDF
Regional difference and dynamic mechanism of locality of the Chinese farming-pastoral ecotone based on geotagged photos from Panoramio 被引量:1
2
作者 WANG Fang LI Yixi +1 位作者 DONG Ying ZHU Xiaohua 《Journal of Arid Land》 SCIE CSCD 2018年第2期316-333,共18页
Cross-regional locality research reflects the influences of natural environment and the human activities due to the abundant land types and the multiple landscape combinations in related regions. The Chinese farming-p... Cross-regional locality research reflects the influences of natural environment and the human activities due to the abundant land types and the multiple landscape combinations in related regions. The Chinese farming-pastoral ecotone is a typical large-scale region but few studies were conducted. This research contributed to the understanding of cross-regional locality of the Chinese farming-pastoral ecotone from different scales, including national, sectional, and provincial administrative units by utilizing geotagged photos(GTPs) obtained from the Panoramio website. The major results were as follows:(1) the locality elements of the Chinese farming-pastoral ecotone included 52 free nodes classified into 8 types of scene attributes;(2) there were huge differences between locality elements of different regions, and there was a negative correlation between the similarity degree of elements of different provinces and their spatial distances;(3) the Chinese farming-pastoral ecotone could be divided into the northern, central and southern sections, whose localities had differences in element constitution, association structure and the strength of elements, system stability and the anti-interference capability; and(4) the evolution of the localities of the northern and central sections was mainly influenced by human activities, while the locality of southern section retained more natural features. On a theoretical level, this research aimed to establish the research methodology of locality from the perspective of open data on the web with strong operability and replicability. On a practical level, this research could enrich the structuring recognition of the locality of the Chinese farming-pastoral ecotone and the comprehension of its dynamic mechanism. The results provide a reference for locality differentiation protection and the development of a cross-regional scale. 展开更多
关键词 administrative units geotagged photos LANDSCAPE LOCALITY NETWORKS regional differences
下载PDF
The mapping methods and division of tectonic units of the regional tectonic map in the eastern China seas and adjacent regions 被引量:1
3
作者 YIN Yanhong ZHANG Xunhua WEN Zhenhe GUO Zhenxuan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2009年第4期57-64,共8页
The geological-geophysical map series of the eastern China seas and adjacent region (1:1 000 000) will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The... The geological-geophysical map series of the eastern China seas and adjacent region (1:1 000 000) will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate (Pacific Plate, Eurasian Plate and Philippine Sea Plate). The second-order tectonic unit is tectonic domain (East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain). The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River (Yangtze) Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells. 展开更多
关键词 regional tectonic map eastern China seas geological tectonic units DIVISION
下载PDF
Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats 被引量:1
4
作者 Yang Wang Zhouyan Feng +1 位作者 Jing Wang Xiaojing Zheng 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第11期1138-1144,共7页
The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear. To investigate the behavior of indi-vidual neurons in response to ... The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear. To investigate the behavior of indi-vidual neurons in response to somatosensory inputs in the hippocampal CA1 region, we recorded and analyzed changes in local ifeld potentials and the ifring rates of individual pyramidal cells and interneurons during tail clamping in urethane-anesthetized rats. We also explored the mechanisms underlying the neuronal responses. Somatosensory stimulation, in the form of tail clamping, chan-ged local ifeld potentials into theta rhythm-dominated waveforms, decreased the spike ifring of py-ramidal cells, and increased interneuron ifring. In addition, somatosensory stimulation attenuated orthodromic-evoked population spikes. These results suggest that somatosensory stimulation sup-presses the excitability of pyramidal cells in the hippocampal CA1 region. Increased inhibition by local interneurons might underlie this effect. These ifndings provide insight into the mechanisms of signal processing in the hippocampus and suggest that sensory stimulation might have thera-peutic potential for brain disorders associated with neuronal hyperexcitability. 展开更多
关键词 nerve regeneration somatosensory stimulation tail clamping hippocampal CA1 region local field potential unit spike population spike EXCITABILITY 973 Program neural regeneration
下载PDF
A STUDY ON THE APPLICATION OF REGIONAL PARAMETERS IN REMOTE SENSING DIGITAL THEMATIC MAPPING
5
作者 Fu Shuxing Zhang Chonghou Li Xiuyun(Institute of Geography, CAS, Bejing 100101 People’s Republic of China) 《Journal of Geographical Sciences》 SCIE CSCD 1996年第4期54-60,共7页
The present paper discusses the implications and drictions of the roponalparameters used in image recognihon, classification and mapping. lt is indispensablefor improving the accuracy of image classification and mappi... The present paper discusses the implications and drictions of the roponalparameters used in image recognihon, classification and mapping. lt is indispensablefor improving the accuracy of image classification and mapping quality. It focuseson the discussion of the theory and methodology for the detenninahon of ndonalparameters for spatial information including method for analysis of aukiliary datorelevan to geography and Anowledge-based roponal parameter research method.Applied researches on roponal parameters are also catried out in combination withpattem recoguhon and typological mapping of saline-alkali soils. 展开更多
关键词 regional parameter geo-science analysis micro-geomorphic unit
下载PDF
The Evolutionary Characteristics of Seismic Activity in the Sichuan-Yunnan Region,China
6
作者 Lan Congxin,Guo Xin and Zhang YafangSeismological Bureau of Beijing Municipality,Beijing 100080,China 《Earthquake Research in China》 2002年第2期138-146,共9页
Based on the earthquake activity characteristics of the diamond block in the Sichuan- Yunnan region and by using the method of the meso-scope damage dynamics and damage evolution, we studied the damage evolution proce... Based on the earthquake activity characteristics of the diamond block in the Sichuan- Yunnan region and by using the method of the meso-scope damage dynamics and damage evolution, we studied the damage evolution process for moderately strong earthquakes along two seismic belts. The original combination patterns of all the units which illuminate the changes from stable state to destroyed state are given. All these patterns can direct the earthquake prediction practice in this region. 展开更多
关键词 Diamond block in the Sichuan-Yunnan region Damage evolution Evolutionary array Original combination patterns of all the units
下载PDF
On Palaeozoic Tectonics in the Alxa Region, Inner Mongolia, China 被引量:32
7
作者 WU Tairan HE Guoqi ZHANG Chen 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1998年第3期256-263,共8页
Abstract: Two ophiolitic mélange belts in the Late Carboniferous formations have been discovered recently in the Alxa region. One is in the Engger Us fault and possesses properties of oceanic crust. The other is ... Abstract: Two ophiolitic mélange belts in the Late Carboniferous formations have been discovered recently in the Alxa region. One is in the Engger Us fault and possesses properties of oceanic crust. The other is in the Badain Jaran fault and shows properties of a back-arc basin. These two faults, together with the Yagan fault, constitute the important boundaries of tectonic units in the Alax region. The four tectonic units delimited by these faults are different in rock assemblages, metamorphism and geochemistry. They reflect the nature of tectonic environments in which they are found. The tectonic units may be traced and correlated to the eastern and western neighbouring areas. The formation and evolution process of the units and their interaction in the Alxa region may be described in terms of the evolution of the Palaeo-Mongolian Ocean and its continental margins. 展开更多
关键词 Alxa region PALAEOZOIC tectonic unit evolution features
下载PDF
Study of crust-mantle transitional zone along the northeast margin of Qinghai-Xizang plateau 被引量:1
8
作者 LAI Xiao-ling(赖晓玲) +3 位作者 ZHANG Xian-kang(张先康) FANG Sheng-ming(方盛明) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第2期144-151,共8页
This study deals with complexity, frequency spectrum and velocity model of the crust-mantle transitional zone in different tectonic units along the northeast margin of Qinghai-Xizang plateau, based on PmP waveform dat... This study deals with complexity, frequency spectrum and velocity model of the crust-mantle transitional zone in different tectonic units along the northeast margin of Qinghai-Xizang plateau, based on PmP waveform data from two deep seismic sounding profiles passing through the area. It reveals that Moho has stable tectonic features in Ordos and Lingzhong basins, where crust and mantle are coupled as first-order discontinuity. Moho shows obvious signs of activity in Haiyuan seismic region and in the contact zone between Bayanhar block and Qaidam block. Crust and mantle in these two areas are coupled as complicated crust-mantle transitional zone consisting of multiple laminae with alternate high and low velocities, totaling 20 km in thickness. The difference between Moho of different tectonic units reflects heterogeneity of the coupled crust-mantle zone; the difference between fine structures of Haiyuan seismic region and Maqin fault zone reflects different deep material composition of the two continent-continent collision zones and the interaction between blocks. 展开更多
关键词 crust-mantle transitional zone tectonic units Haiyuan seismic region Maqin fault zone
下载PDF
The Unexpected Existence of Coding and Non-Coding Fragments along the Eukaryotic Gene
9
作者 Pietro Volpe 《Advances in Biological Chemistry》 2015年第2期98-125,共28页
The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;it... The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;its entire –CH3 served instead for building N6-methyladenine and 5-methylcytosine on bacterial DNA and 5-methylcytosine alone on human DNA. In humans, although a slight extra-S asymmetric methylation appeared de novo yielding on parental DNA 5’-m5CpC-3’/ 3’-GpG-5’, 5’-m5CpT-3’/3’-GpA-5’ and 5’-m5CpA-3’/3’-GpT-5’ monomethylated dinucleotide pairs, a heavy symmetric methylation involved in S semiconservatively newly made DNA to guarantee genetic maintenance of –CH3 in 5’-m5CpG-3’/3’-Gpm5C-5’ dimethylated dinucleotide pairs. In this framework, an inverse correlation was found between bulk genomic DNA methylation occurring in S and bulk polyA-containing pre-mRNA transcription taking place in G1 and G2. Thus, probes of 1 × 106 Daltons (constructed using sheared by sonication newly made methylated DNA filaments) revealed a modular organization in genes: after the hypermethylated promoter, they exhibited an alternation of unmethylated coding and methylated uncoding sequences. This encouraged the search for a language that genes regulated by methylation should have in common. An initial deciphering of restriction minimaps with hypomethylatable exons vs. hypermethylatable promoters and introns was improved when the bisulfite technique allowed a direct sequencing of m5C. In lymphocytes, where the transglutaminase gene is inactive, its promoter exhibited two fully methylated CpG-rich domains at 5’ and one fully unmethylated CpG-rich domain at 3’, including the site +1 and a 5’-UTR. At variance, in HUVEC cells, where the transglutaminase gene is active, in the first CpG-rich domain of promoter few doublets lost their –CH3. Such an inverse correlation suggested new hypotheses especially in connection with repair-modification: UV radiation would cause demethylation in given loci of a promoter by chance, whilst even a partial demethylation in this promoter would be able to resume a previously silent pre-mRNA transcription. 展开更多
关键词 CODinG vs. NON-CODinG Pre-Messenger RNA regions EXONS and inTRONS Multigenic and MONOGENIC TRANSCRIPTIONAL Units Regulation of Gene Expression Repair-Modification
下载PDF
A Piece of a Puzzle of Haplotypes for the Indian Ocean Hawksbill Turtle
10
作者 Rita Anastácio Mário Jorge Pereira 《Natural Resources》 2017年第8期548-558,共11页
The Indian Ocean basin has much to reveal in what concerns marine turtles. Its regional management units (RMUs) are still lacking molecular data to define conservation strategies and priorities. Vamizi Island is one o... The Indian Ocean basin has much to reveal in what concerns marine turtles. Its regional management units (RMUs) are still lacking molecular data to define conservation strategies and priorities. Vamizi Island is one of the best known rookeries in the north of the Mozambique Channel. A mitochondrial DNA analysis revealed 14 haplotypes for the hawksbill turtle’s nesting and foraging in/near Vamizi, twelve of which were new in 2011. Though more studies inside the Channel are needed, Vamizi Island possibly contributes with hatchlings for other locations. More knowledge is important to define priorities for management units inside the Indian Ocean. 展开更多
关键词 Eretmochelys imbricata MTDNA HAPLOTYPE regional Management Unit Mozambique Channel
下载PDF
Basic Facts about Xinjiang and Ideas on Implementation of Western Region Development
11
《China's Foreign Trade》 2000年第11期31-34,共4页
关键词 Basic Facts about Xinjiang and ideas on Implementation of Western region Development
下载PDF
Terrestrial carbon sequestration in southeast and south-central United States
12
作者 Fengxiang HAN M John Plodinec +3 位作者 Yi SU David L. Monts Zhongpei LI Baoshan XING 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期266-266,共1页
关键词 全球变暖 二氧化碳 温室效应 排放量
下载PDF
The Poorly Known Northeast Atlantic Regional Management Unit for Loggerhead (Caretta caretta)
13
作者 Inês M. Ferreira Ana Raquel de Sales +1 位作者 Mário J. Pereira Rita Anastácio 《Open Journal of Ecology》 2022年第8期529-536,共8页
Loggerheads are distributed by ten Regional Management Units (RMUs) worldwide. The Atlantic Ocean houses three of these: the Northwest, Southwest and Northeast RMUs. The most studied is, so far, the Northwest RMU, but... Loggerheads are distributed by ten Regional Management Units (RMUs) worldwide. The Atlantic Ocean houses three of these: the Northwest, Southwest and Northeast RMUs. The most studied is, so far, the Northwest RMU, but the other two have focused attention of researchers. In contrast, marine turtles from the African Atlantic region (Southeast) belong to a complex but little-known region. What is their role in the Atlantic? Are these RMUs connected? To understand these questions, research was made of reports and publications concerning the Northeast Atlantic (NEA) RMU. The asymmetry in information and available knowledge about NEA is high when compared to other RMUs. This demonstrates that there is still a lack of conservation programs besides Cape Verde, and that there is difficulty in transforming data (nesting ecology, molecular, telemetry, etc.) into publications. However, this issue is evident for other marine turtle species of East African Atlantic. There is a need for better scientific support, to enable local conservation programs to deliver data in reports, and even scientific publications. There are so many aspects of loggerhead’s life cycle that will only be unravelled by more and better supported studies. This is a paper that, by analysing the available information of the NEA loggerhead RMU, reflects the following steps to address in loggerhead conservation for the African Atlantic coast. 展开更多
关键词 LOGGERHEAD Caretta caretta regional Management Units African Atlantic region
下载PDF
Aeromagnetic data and geological structure of continental China:A review 被引量:8
14
作者 熊盛青 佟晶 +1 位作者 丁燕云 李占奎 《Applied Geophysics》 SCIE CSCD 2016年第2期227-237,416,共12页
We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data coll... We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data collected for more than 50 years, a series of 1:5000000 and 1:1000000 aeromagnetic maps of continental China were compiled using state-of-the-art digital technology, and data processing and transformation. Guided by plate tectonics and continental dynamics, rock physical properties, and magnetic anomalies, we compiled maps of the depth of the magnetic basement of continental China and the major geotectonic units, and presented newly detected geological structures based on the aeromagnefic data. 展开更多
关键词 regional aeromagnetic anomalies magnetic basement FAULTS magmatic rocks structural units
下载PDF
Extreme Weather Disruptions and Emergency Preparedness Among Older Adults in Ohio: An Eight-County Assessment 被引量:1
15
作者 Smitha Rao Fiona C.Doherty +3 位作者 Anthony Traver Marisa Sheldon Emma Sakulich Holly Dabelko‑Schoeny 《International Journal of Disaster Risk Science》 SCIE CSCD 2024年第2期213-225,共13页
The disproportionate risks and impacts of climate change and extreme weather on older adults are increasingly evident. While especially true in disaster-prone areas, human-caused climate change introduces an element o... The disproportionate risks and impacts of climate change and extreme weather on older adults are increasingly evident. While especially true in disaster-prone areas, human-caused climate change introduces an element of uncertainty even in previously identified “safe” regions such as the Midwestern United States. Using a cumulative disadvantage and vulnerability-informed framework and descriptive statistics from multiple data sources, this article provides an overview of climate impacts, vulnerabilities, and county-level characteristics, focusing on older adults living in Central Ohio. A comparative multiple-case study methodology was used to triangulate regionally representative primary and secondary data sources to examine state and county-level measures of vulnerability, emergency preparedness, and disruptions caused by extreme weather among older adults across eight counties in Central Ohio. Seventy-eight percent of older adults in the sample reported being prepared for emergencies per Federal Emergency Management Agency guidelines. Older adults in Union County reported the highest rates of preparedness, while those in Fayette County reported the lowest. County-level rates of disruption of life activities by extreme weather ranged widely. Among the most rural in the region, Fayette County emerged as uniquely disadvantaged, with the lowest median income, the most vulnerable across multiple social vulnerability dimensions, and the most reported disruptions to life activities from extreme weather. County profiles offer a snapshot of existing vulnerabilities, socioeconomic conditions, special needs, preparedness, and current disruptions among older adults in the region and can inform resource mobilization across community and policy contexts. 展开更多
关键词 Disaster preparedness Extreme weather Midwestern united States Older adults regional assessment Social vulnerability
原文传递
Effects of white noise on procedural pain-related cortical response and pain score in neonates:A randomized controlled trial 被引量:6
16
作者 Xuyan Ren Li Li +2 位作者 Siya Lin Chunxia Zhong Bin Wang 《International Journal of Nursing Sciences》 CSCD 2022年第3期269-277,I0001,共10页
Objectives To evaluate the effects of white noise on pain-related cortical response,pain score,and behavioral and physiological parameters in neonates with procedural pain.Methods A double-blind,randomized controlled ... Objectives To evaluate the effects of white noise on pain-related cortical response,pain score,and behavioral and physiological parameters in neonates with procedural pain.Methods A double-blind,randomized controlled trial was conducted.Sixty-six neonates from the Neonatal Intensive Care Unit in a university-affiliated general hospital were randomly assigned to listen to white noise at 50 dB(experimental group)or 0 dB(control group)2 min before radial artery blood sampling and continued until 5 min after needle withdrawal.Pain-related cortical response was measured by regional cerebral oxygen saturation(rScO_(2))monitored with near-infrared spectroscopy,and facial expressions and physiological parameters were recorded by two video cameras.Two assessors scored the Premature Infant Pain Profile-Revised(PIPP-R)independently when viewing the videos.Primary outcomes were pain score and rScO_(2)during arterial puncture and 5 min after needle withdrawal.Secondary outcomes were pulse oximetric oxygen saturation(SpO_(2))and heart rate(HR)during arterial puncture,and duration of painful expressions.The study was registered at the Chinese Clinical Trial Registry(ChiCTR2200055571).Results Sixty neonates(experimental group,n=29;control group,n=31)were included in the final analysis.The maximum PIPP-R score in the experimental and control groups was 12.00(9.50,13.00),12.50(10.50,13.75),respectively(median difference−0.5,95%CI−2.0 to 0.5),and minimum rScO_(2)was(61.22±3.07)%,(61.32±2.79)%,respectively(mean difference−0.325,95%CI−1.382 to 0.732),without significant differences.During arterial puncture,the mean rScO_(2),HR,and SpO_(2)did not differ between groups.After needle withdrawal,the trends for rScO_(2),PIPP-R score,and facial expression returning to baseline were different between the two groups without statistical significance.Conclusion The white noise intervention did not show beneficial effects on pain-related cortical response as well as pain score,behavioral and physiological parameters in neonates with procedural pain. 展开更多
关键词 Facial expression intensive care units NEONATES Procedural pain Premature infant pain profile-revised Radial artery regional cerebral oxygen saturation White noise
下载PDF
Lithostructural controls in Douala-Buea Region landscape (SW Cameroon margin):Insights from morphometric analysis 被引量:1
17
作者 Christian BALLA ATEBA Sébastien OWONA +3 位作者 Moussa NSANGOU NGAPNA Véronique MANGA TSIMI DieudonnéMINYEM Joseph MVONDO ONDOA 《Journal of Mountain Science》 SCIE CSCD 2021年第1期68-87,共20页
The Douala-Buea Region(DBR;4°-5°N,9°-10°30’E),a portion of the southern Cameroon passive margin,developed on the Proterozoic granito-gneissic basement and the Cretaceous to Recent volcanosedimenta... The Douala-Buea Region(DBR;4°-5°N,9°-10°30’E),a portion of the southern Cameroon passive margin,developed on the Proterozoic granito-gneissic basement and the Cretaceous to Recent volcanosedimentary cover,was explored in order to evaluate the lithology and tectonics controls on its landscape usingthequalitativeandquantitative geomorphological analyses based on 30 m resolution Digital Elevation Models(DEM)and field evidences.This area displays an uneven and complex landscape differentiated into four morphological units:Douala,Nkondjock,Kumba and Buea Units.The Douala Unit corresponds to the Coastal Plain and is extended on the Douala-Kribi/Camposedimentarybasin.The Nkondjock Unit represents a middle plateau developed on a Proterozoic granito-gneissic basement.The Kumba Unit matches with the southernmost volcanic Western Cameroon High Plateau.The Buea Unit corresponds to the Mount Cameroon stratovolcano.The relief analysis through mountain-front sinuosity(Smf,1.19–1.43)and relative relief ratio(Rr,0.10–2.31)vary from one unit to another.The drainage network analysis including drainage patterns,stepped longitudinalriverprofiles,theassociated morphometric indexes,notably the concavity index(IC,0.56–0.88),deviation(D,267–2912 m),basin asymmetry factor(A_(F),6.37–42.12),hypsometric integral(HI,0.10–0.29),valley floor width to valley height ratio(V_(f),0.36–2.75),elongation ratio(R_(e),0.30–0.50),watershed slope(S,6.88–88.88)and stream length gradient index(SL,0–3332)vary from one basin to another too.These results also show the heterogeneous and uneven DBR landscape controlled by its lithology and active tectonics.The drainage system reveals concave to concavo-convex longitudinal river profile shapes with knick points,asymmetric basins,and fault reactivations,and highlights the tectonics activity that used to occur through the time and their control on the morphology.Together,they document the lithostructural controls on the DBR landscape evolution,extendable in the whole SW Cameroon margin. 展开更多
关键词 Morphometric indices Lithological control Structural control Morphological units Douala-Buea region SW Cameroon margin
下载PDF
Geotectonic evolution of lunar LQ-4 region based on multisource data 被引量:1
18
作者 Jianping Chen Yanbo Xu +5 位作者 Xiang Wang Shujun He Danping Yan Shaofeng Liu Yongliao Zou Yongchun Zheng 《Geoscience Frontiers》 SCIE CAS CSCD 2014年第2期227-235,共9页
The Sinus Iridum region, the first choice for China's"Lunar Exploration Project"is located at the center of the lunar LQ-4 area and is the site of Chang'e-3 (CE-3)'s soft landing. To make the scientific explora... The Sinus Iridum region, the first choice for China's"Lunar Exploration Project"is located at the center of the lunar LQ-4 area and is the site of Chang'e-3 (CE-3)'s soft landing. To make the scientific exploration of Chang'e-3 more targeted and scientific, and to obtain a better macro-level understanding of the geotectonic environment of the Sinus Iridum region, the tectonic elements in LQ-4 region have been studied and the typical structures were analyzed statistically using data from CE-1, Clementine, LRO and Lunar Prospector missions. Also, the mineral components and periods of mare basalt activities in the study area have been ascertained. The present study divides the tectonic units and establishes the major tectonic events and sequence of evolution in the study area based on morphology, mineral constituents, and tectonic element distribution. 展开更多
关键词 Lunar Tectonic elements Tectonic units Evolution LQ-4 region
下载PDF
Why the Cold War Will Never Return to World Politics
19
作者 Gültekin Sümer 《International Relations and Diplomacy》 2019年第11期517-532,共16页
Every serious confrontation between the United States and Russia evokes new cold war debates.The Cold War found its true meaning because it had achieved to create its own momentum within time.This question is a great ... Every serious confrontation between the United States and Russia evokes new cold war debates.The Cold War found its true meaning because it had achieved to create its own momentum within time.This question is a great test in terms of measuring the level that today’s international relations has reached:Is cold war still relevant in a global politics?The answer to be given to this question depends on whether any cold war can be maintained against all the pluralistic tendencies of international relations.It will be a negative one because the dynamics unleashed by globalization are likely to marginalize new cold war regardless of the will to wage and sustain it.For,beyond the will to wage and sustain it,the concept of cold war is a technical issue that can only exist provided that it can achieve to subordinate all the dynamics of the global politics to itself. 展开更多
关键词 cold WAR POWER great POWER regional POWER international system GEOPOLITICS GLOBALIZATION united States Russia
下载PDF
Map of Mafic Dyke Swarms and Related Units of Russia and Adjacent Regions
20
作者 Richard E.ERNST Kenneth L.BUCHAN Svetlana BOTSYUN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期22-23,共2页
Work is currently underway to produce a map in Arc GISTM 10 of the mafic dyke swarms and related units(volcanics,sills and layered intrusions)of Russia and adjacent regions at a scale of 1:5,000,000.Over the past
关键词 Map of Mafic Dyke Swarms and Related Units of Russia and Adjacent regions
下载PDF
上一页 1 2 54 下一页 到第
使用帮助 返回顶部