全文获取类型
收费全文 | 801篇 |
免费 | 16篇 |
出版年
2024年 | 5篇 |
2023年 | 16篇 |
2022年 | 17篇 |
2021年 | 28篇 |
2020年 | 38篇 |
2019年 | 15篇 |
2018年 | 31篇 |
2017年 | 25篇 |
2016年 | 19篇 |
2015年 | 21篇 |
2014年 | 15篇 |
2013年 | 49篇 |
2012年 | 38篇 |
2011年 | 55篇 |
2010年 | 43篇 |
2009年 | 46篇 |
2008年 | 58篇 |
2007年 | 51篇 |
2006年 | 59篇 |
2005年 | 49篇 |
2004年 | 38篇 |
2003年 | 23篇 |
2002年 | 26篇 |
2001年 | 25篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有817条查询结果,搜索用时 15 毫秒
101.
本文以英国的史实为主,法国的史实为辅,探讨了大规模圈地运动之前英国和法国的公地制度长期经历的侵蚀与反侵蚀的斗争。本文试图说明,近代圈地运动的兴起,公地制度的衰亡,圈地者同反圈地者之间剧烈的冲突,决非突然发生,而是有着非常深远的历史根源。 相似文献
102.
旅游产业集聚会影响地区收入差距吗?——基于中国省际面板数据的门槛回归分析 总被引:1,自引:0,他引:1
本文利用中国30个省市区1999年~2009年面板数据,分别从线性和非线性两个角度实证检验了旅游产业集聚对地区收入差距的影响,估计结果显示:一方面,旅游产业集聚对地区收入差距具有显著线性负向影响效应;另一方面,通过构建非线性面板门槛模型,进一步检验了旅游产业集聚对地区收入差距影响效应的门槛特征,具体而言,旅游产业集聚对地区收入差距负向影响效应不仅存在基于旅游产业集聚的单一门槛特征,而且也存在基于经济发展水平、基础设施建设与产业结构升级的三重门槛特征。 相似文献
103.
鉴于目前我国在构建价值转移模型中存在的限制因素,本文采用基于Meta分析的价值转移方法并尝试利用国外游憩活动价值评价的实证研究结果,构建基于Meta分析的国际间价值函数转移模型,估算了我国10种游憩活动的日平均消费者剩余.通过将价值转移模型估算的游憩活动价值“转移值”与国内97个游憩价值评价的“真实值”做比较,对价值转移模型的有效性和可靠性进行统计检验,平均转移误差为18.74%.最后,总结了提高我国Meta回归价值转移模型的具体、可操作性方法及途径. 相似文献
104.
Katsumi Ueno Guang R. Shi Shu-Zhong Shen 《Alcheringa: An Australasian Journal of Paleontology》2013,37(2):257-273
Fusulinoideans from the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone of the lower part of the Chandalaz Formation in the Senkina Shapka section in South Primorye, Far East Russia, are described. The fusulinoidean zone is assigned to the early Midian (=Capitanian: late Middle Permian) based mainly on the morphologie and biostratigraphic characteristics of Metadoliolina dutkevitchi. Previously, a Midian age has been established for the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone by the coexistence of Lepidolina species. However, the occurrence of Lepidolina with the two zonal species in this area has not been verified by the illustration of Lepidolina specimens. We examined a fusulinoidean-bearing sample from the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone, and three fusulinoidean species, Monodiexodina sutchanica, Pseudofusulina sp. and Metadoliolina dutkevitchi, are de-scribed and illustrated. 相似文献
105.
Peng, Y. & Shi, G.R., June, 2008. New Early Triassic Lingulidae (Brachiopoda) genera and species from South China. Alcheringa 32, 149–170. ISSN 0311-5518. Two new genera, Sinolingularia gen. nov. and Sinoglottidia gen. nov., together with three new species, Sinolingularia huananensis gen. et sp. nov., Sinolingularia yini gen. et sp. nov. and Sinoglottidia archboldi gen. et sp. nov., are described on the basis of a large collection of well-preserved specimens from several sections straddling the Permian – Triassic boundary in South China. 相似文献
106.
Weihong He G. R. Shi Qinglai Feng Yuanqiao Peng 《Alcheringa: An Australasian Journal of Paleontology》2013,37(3):271-284
Cretaceous polar dinosaur faunas were taxonomically diverse, which suggests varied strategies for coping with the climatic stress of high latitudes. Some polar dinosaurs, particularly larger taxa such as the duckbill Edmontosaurus Lambe, 1917, were biomechanically and energetically capable of migrating over long distances, up to 2600 km. However, current evidence strongly suggests many polar dinosaurs (including sauropods, large and small theropods, and ankylosaurs of New Zealand) overwintered in preference to migration. Certain groups also appear more predisposed to overwintering based on their physical inability (related to biomechanics, natural history, or absolute size) to migrate, such as ankylosaurs and many small taxa, including hypsilophodontids and troodontids. Low-nutrient subsistence is found to be the best overwintering method overall, although the likelihood that other taxa employed alternative means remains plausible. Despite wide distribution of some genera, species-level identification is required to assess the applicability of such distributions to migration distances. Presently, such resolution is not available or contradicts the migration hypothesis. 相似文献
107.
Arturo César Taboada Arthur J. Mory Guang-Rong Shi David W. Haig María Karina Pinilla 《Alcheringa: An Australasian Journal of Paleontology》2013,37(2):207-223
Taboada, A.C., Mory, A.J., Shi, G.R., Haig, D.W. & Pinilla, M.K., 12.11.2014. An Early Permian brachiopod–gastropod fauna from the Calytrix Formation, Barbwire Terrace, Canning Basin, Western Australia. Alcheringa 39, xxx–xxx. ISSN 0311-5518A small brachiopod–gastropod fauna from a core close to the base of the Calytrix Formation within the Grant Group includes the brachiopods Altiplecus decipiens (Hosking), Myodelthyrium dickinsi (Thomas), Brachythyrinella narsarhensis (Reed), Neochonetes (Sommeriella) obrieni Archbold, Tivertonia barbwirensis sp. nov. and the gastropod Peruvispira canningensis sp. nov. The fauna has affinities with that of the late Sakmarian?early Artinskian Nura Nura Member directly overlying the Grant Group in other parts of the basin but, as with all lower Cisuralian (and Pennsylvanian) glacial strata in Western Australia, its precise age remains poorly constrained, especially in terms of correlation to international stages. Although the Calytrix fauna lies within the Pseudoreticulatispora confluens Palynozone, the only real constraint on its age (and that of the associated glacially influenced strata) is from Sakmarian (Sterlitamakian) and stratigraphically younger faunas. A brief review of radiometric ages from correlative strata elsewhere in Gondwana shows that those ages need to be updated. The presence of Asselian strata and the position of the Carboniferous?Permian boundary remain unclear in Western Australia.Arturo César Taboada [ataboada@unpata. edu. ar], CONICET-Laboratorio de Investigaciones en Evolución y Biodiversidad (LIEB), Facultad de Ciencias Naturales, Sede Esquel, Universidad Nacional de la Patagonia ‘San Juan Bosco’, Edificio de Aulas, Ruta Nacional 259, km. 16,5, Esquel U9200, Chubut, Argentina; Arthur Mory [arthur. mory@dmp. wa. gov. au], Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Guang R. Shi [grshi@deakin. edu. au], School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; David W. Haig [david. haig@uwa. edu. au], School of Earth and Environment (M004), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; María Karina Pinilla [mkpinilla@fcnym. unlp. edu. ar], División Paleozoología Invertebrados, Museo de Ciencias Naturales de La Plata, Paseo del Bosque s/n, 1900 La Plata, Buenos Aires, Argentina. 相似文献
108.
109.
论中原地区在中国文明化进程中的作用和影响 总被引:1,自引:0,他引:1
本文认为,中原地区在中国文明化进程中的作用是一个逐步强化的过程,在文明化的初期阶段,这里更多的吸收了周边地区各种文化的一些因素,在夏商周时期逐步成为文明中心.作为文明中心,它的影响作用主要表现在文化和社会发展的深层次方面,即社会的观念形态和礼仪制度等方面;大多数情况下,不是体现在文化的表层层面,即物质文化产品的基本形态方面.文明中心的进一步强化,使中原文明成为了中国古代文明的基本表现形态. 相似文献
110.