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四川有蹄动物区系形成的探讨 被引量:2
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作者 曾宗永 宋志明 +1 位作者 邓小忠 孙奇志 《四川大学学报(自然科学版)》 CAS CSCD 1994年第4期540-545,共6页
对四川有蹄动物现生种和化石种进行了比较,认为四川现今属东洋界的西南区和华中区有蹄动物区系是第三世纪上新世至第四纪中、晚更新世大熊猫。剑齿象(Ailuropoda-Stegodon)动物群的发展和继续,属古北界的青藏高... 对四川有蹄动物现生种和化石种进行了比较,认为四川现今属东洋界的西南区和华中区有蹄动物区系是第三世纪上新世至第四纪中、晚更新世大熊猫。剑齿象(Ailuropoda-Stegodon)动物群的发展和继续,属古北界的青藏高原区,相当于晚更新世的北方动物群。同时还讨论了四川有蹄动物的兴衰演替与地理迁移,以及横断山脉对有蹄动物的保存分化和扩散的特殊意义。 展开更多
关键词 四川 有蹄动物 区系形成
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东亚植物区系形成新观点
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《科学中国人》 2018年第6期13-13,共1页
中科院昆明植物研究所孙航研究组最新研究论文发表于National Science Review.在中国-日本森林植物亚区和中国-喜马拉雅森林植物亚区的基础上,进-步将以古特有或孑遗植物集中分布的中国-日本森林植物亚区(华中-华东地区为核心)界定为... 中科院昆明植物研究所孙航研究组最新研究论文发表于National Science Review.在中国-日本森林植物亚区和中国-喜马拉雅森林植物亚区的基础上,进-步将以古特有或孑遗植物集中分布的中国-日本森林植物亚区(华中-华东地区为核心)界定为“水杉植物区系(Metasequoia Flora)”. 展开更多
关键词 森林植物 区系形成 昆明植物研究所 东亚 喜马拉雅 论文发表 植物区系 华东地区
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广西森林溪流淡水鱼类区系研究 被引量:3
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作者 李红敬 《信阳师范学院学报(自然科学版)》 CAS 2002年第2期199-203,共5页
通过调查发现 ,分布于广西森林溪流中的淡水鱼类有 92种 ,分别隶属于 5目、16科、6 3属 .鲤形目占 6 4.1% ,鲇形目占 11.96 % ,鲈形目占 2 0 .6 5 % ,合鳃目占 1.0 1% ,形目占 2 .2 7% .其中鲤科鱼类占总种数的 46 .7% .可划分为热带... 通过调查发现 ,分布于广西森林溪流中的淡水鱼类有 92种 ,分别隶属于 5目、16科、6 3属 .鲤形目占 6 4.1% ,鲇形目占 11.96 % ,鲈形目占 2 0 .6 5 % ,合鳃目占 1.0 1% ,形目占 2 .2 7% .其中鲤科鱼类占总种数的 46 .7% .可划分为热带平原、江河平原、中印山区、上第三纪、北方平原 5个区系复合体 .在不同的海拔高度鱼类分布不同 ,具有明显的山区特征 .广西森林溪流淡水鱼类区系形成与广西自然环境的历史演变有密切关系 . 展开更多
关键词 淡水鱼类 森林溪流 广西 区系组成 区系划分 区系形成 区系演变
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竹蝗属(Ceracris Walker)的支序系统学和生物地理学研究 被引量:3
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作者 许升全 蒋国芳 郑哲民 《陕西师范大学学报(自然科学版)》 CAS CSCD 北大核心 2005年第2期115-118,共4页
以黄脊雷蓖蝗为外群,选择20个形态性状对竹蝗属10个种(亚种)的系统发育关系进行分析,并据此探讨了其区系形成.结果表明:竹蝗属可以分为长翅和短翅两个类群,短翅类群包括蒲氏竹蝗、黑翅竹蝗和思茅竹蝗;形态分类中归为短翅类群的贺氏竹蝗... 以黄脊雷蓖蝗为外群,选择20个形态性状对竹蝗属10个种(亚种)的系统发育关系进行分析,并据此探讨了其区系形成.结果表明:竹蝗属可以分为长翅和短翅两个类群,短翅类群包括蒲氏竹蝗、黑翅竹蝗和思茅竹蝗;形态分类中归为短翅类群的贺氏竹蝗是长翅类群中的一个高度特化的种类;中国的西南地区是竹蝗属的分布中心,同时也是其起源和物种分化中心. 展开更多
关键词 竹蝗属 生物地理学 支序系统学 系统发育关系 形态性状 区系形成 黑翅竹蝗 形态分类 分布中心 西南地区 物种分化 类群 外群 亚种
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GIS-Based and Data-Driven Bivariate Landslide-Susceptibility Mapping in the Three Gorges Area, China 被引量:15
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作者 BAI Shi-Biao WANG Jian +3 位作者 LU Guo-Nian ZHOU Ping-Gen HOU Sheng-Shan XU Su-Ning 《Pedosphere》 SCIE CAS CSCD 2009年第1期14-20,共7页
A detailed landslide-susceptibility map was produced using a data-driven objective bivariate analysis method with datasets developed for a geographic information system (GIS). Known as one of the most landslide-pron... A detailed landslide-susceptibility map was produced using a data-driven objective bivariate analysis method with datasets developed for a geographic information system (GIS). Known as one of the most landslide-prone areas in China, the Zhongxian-Shizhu Segment in the Three Gorges Reservoir region of China was selected as a suitable case because of the frequency and distribution of landslides. The site covered an area of 260.93 km^2 with a landslide area of 5.32 km^2. Four data domains were used in this study, including remote sensing products, thematic maps, geological maps, and topographical maps, all with 25 m × 25 m pixels. Statistical relationships for landslide susceptibility were developed using landslide and landslide causative factor databases. All continuous variables were converted to categorical variables according to the percentile divisions of seed cells, and the corresponding class weight values were calculated and summed to create the susceptibility map. According to the map, 3.6% of the study area was identified as high-susceptibility. Extremely low-, very low-, low-, and medium-susceptibility zones covered 19.66%, 31.69%, 27.95%, and 17.1% of the area, respectively. The high- and medium-hazardons zones are along both sides of the Yangtze River, being in agreement with the actual distribution of landslides. 展开更多
关键词 causative factors landslide-susceptibility statistical approaches Three Gorges area
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Integrated Approach to the Formation of Service Areas for Urban Substations of Different Voltage
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作者 Nataly Skobeleva Oleg Borscevskis Svetlana Guseva Lubov Petrichenko 《Journal of Energy and Power Engineering》 2012年第8期1358-1362,共5页
UPSS (urban power supply system) is a part of the region or the state power supply system. UPSS development is closely connected with region power supply system development as a whole. The decision of questions of l... UPSS (urban power supply system) is a part of the region or the state power supply system. UPSS development is closely connected with region power supply system development as a whole. The decision of questions of long-term and middle-term planning of UPSS development occurs in the conditions of incompleteness and uncertainty of the initial information. Nevertheless in these conditions the acceptance of development strategy should be based on perspective electric loads of urban TS (transformer substations). There are difficulties with a rational placement of substations in the city with the developed infrastructure. Such problem by theoretically grounded approach to rational formation of UPSS is solved. The hierarchical structure of the organizational construction, voltage levels and load densities is considered. The mathematical and geometrical modeling of service areas for transformer substations of different voltage is fulfilled. The method of graphic placement of transformer substations in the city territory for new substations at existing structure of networks is offered. The aim of the work is to present the new uniform approach which allows finding a rational decision for new substations' placement in cities with developed infrastructure on the beginning design stages in conditions of the information uncertainty. The calculation program Microsoft EXCEL and the graphic program AutoCAD are used for realization of method. 展开更多
关键词 Power system load density voltage level urban substations.
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中新世CO^2浓度与气候
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《生物进化》 2008年第1期7-7,共1页
中新世出现了一系列的气候事件,是现代生物区系形成的关键时期。最近研究人员用植物气孔参数的方法恢复了中新世的CO2浓度。
关键词 中新世 关键时期 气候事件 气孔参数 区系形成 浓度变化 研究人员 生物 植物 现代
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Paleogene-Neogene stratigraphic realm and tectonic-sedimentary evolution of the Qilian Mountains and their surrounding areas 被引量:4
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作者 YANG LiRong LI JianXing +8 位作者 YUE LePing WANG HongLiang GUO HuaiJun ZHU XiaoHui ZHU Tao DU Kai ZHANG Rui ZHANG YunXiang GONG HuJun 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第5期992-1009,共18页
The Cenozoic uplift of Qilian Mountains is critical to comprehend the uplift and extension of the Tibet Plateau as well as the formation of the first and second steps in China's topography. This study summarized d... The Cenozoic uplift of Qilian Mountains is critical to comprehend the uplift and extension of the Tibet Plateau as well as the formation of the first and second steps in China's topography. This study summarized dynamic stratigraphic realm comprehensively on the basis of stratigraphic correlation of different Cenozoic sedimentary basin regions of the Qilian Mountains and adjacent mountains. This facilitated the re-creation of the tectonic-sedimentary evolutionary process of the Qilian Mountains and their surrounding areas. The results indicate that during the Early Paleogene(Paleocene-Eocene), the Qilian Mountains were part of an uplift realm. During the Oligocene, Guide-Xining-Lanzhou-Linxia sag basin at the northern margin of the West Qinling Mountains came into being and was subjected to sedimentation. The Suli Basin located between the North and South Qilian paleo-uplifts began to form and undergo sedimentation. Intracontinental orogenic extrusion and basin detachment occurred at the Qilian Mountains during the Miocene, which caused successive uplifts of various mountains, including the Laji, South Qinghai,Jishi, Liupan, and South Shule Mountains. Until Pliocene, Qilian Mountains uplifted continuously and resulted in the shrink,extinction and being eroded of the basins, and aeolian red clay started to accumulate. 展开更多
关键词 Paleogene-Neogene Stratigraphic realm Tectonic-sedimentary evolution Qilian Mountain Tibet Plateau
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