首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   171篇
  免费   2篇
  2022年   3篇
  2021年   2篇
  2020年   9篇
  2018年   5篇
  2017年   6篇
  2016年   6篇
  2015年   1篇
  2014年   3篇
  2013年   10篇
  2012年   11篇
  2011年   11篇
  2010年   14篇
  2009年   17篇
  2008年   16篇
  2007年   10篇
  2006年   8篇
  2005年   5篇
  2004年   10篇
  2003年   6篇
  2002年   8篇
  2001年   4篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1993年   1篇
排序方式: 共有173条查询结果,搜索用时 15 毫秒
171.
为研究古夜郎地区的青铜器铸造技术,本文对贵州可乐墓地2000年出土的33件铜器进行了金相观察和扫描电镜能谱分析,结果表明:战国早期至中期,铜锡合金的配比技术已经进入相对成熟阶段;战国晚期,可乐地区开始规范化、甚至批量化生产铜器;战国末期到西汉前期,铜锡铅合金的配比技术进入较成熟阶段;工匠先后掌握了锡青铜和铅锡青铜的制作性能,能够根据器物选择材质和加工方法;战国中晚期,可乐地区可能能够自行生产巴蜀、石寨山风格铜器,且与两地青铜技术水平相近。  相似文献   
172.
赣南的大山长谷、原始森林里生活着一种非人非鬼又非神的“赣巨人”。有人说他们是狒狒,有人说他们是“木客”,有人说他们是“野人”,也有人说他们是尼革利陀族人。但据笔者考证,他们应该是一种没有经过文明进化的古猿。  相似文献   
173.
Peng, J., Li, J., Slater, S.M., Li, W., Zhu, H. & Vajda, V. October 2017. Triassic palynostratigraphy and palynofloral provinces: evidence from southern Xizang (Tibet), China. Alcheringa 42, 67–86. ISSN 0311-5518.

Palynological analysis was carried out on Middle to Upper Triassic strata from Tulong, Nyalam County, southern Xizang (Tibet), China. Well-preserved miospore (pollen and spore) assemblages and sparse acritarch occurrences were identified. We recognized four formal and one informal biozones based on stratigraphically important taxa and compositional changes through the succession, in ascending order: the Triplexisporites Interval Zone (Anisian), the Staurosaccites quadrifidus Taxon-range Zone (upper Anisian to lower Norian), the Striatella Interval Zone (lower Norian), the Craterisporites rotundus Taxon-range Zone (middle to upper Norian) and the informal ‘Dictyophyllidites harrisii zone’ (Rhaetian). The zonation was supported by marine fossils (e.g., ammonoids and conodonts), and compositional similarity between the zones was examined using non-metric multidimensional scaling (NMDS). Correlation with other representative palynological sequences across Gondwana was also conducted. The presence of miospore taxa not previously recovered from the Late Triassic North and South China palynofloral provinces (e.g., Ashmoripollis reducta, Craterisporites rotundus, Enzonalasporites vigens, Minutosaccus crenulatus, Samaropollenites speciosus and Staurosaccites quadrifidus) calls for a new province in southwestern China, i.e., the Southern Xizang Province. It is proposed here that the modern expression of the northern boundary runs along the Yarlung Zangbo Suture, the remnant of the Tethys that separated the Indian Plate (southern Xizang) and the Lhasa Block during the Late Triassic. This new palynofloral province comprises typical elements of the Onslow Microflora, indicating the need for an extension of this microflora in southern Xizang, China.

Jungang Peng [], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China, University of Chinese Academy of Sciences, Beijing 100049, China, Department of Palaeobiology, Swedish Museum of Natural History, Stockholm 104 05, Sweden; Jianguo Li* [], Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Wenben Li [], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Sam M. Slater [], Vivi Vajda [], Department of Palaeobiology, Swedish Museum of Natural History, Stockholm 104 05, Sweden; Huaicheng Zhu [], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号