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   512篇
  免费   9篇
  2023年   3篇
  2022年   9篇
  2021年   8篇
  2020年   18篇
  2019年   16篇
  2018年   20篇
  2017年   22篇
  2016年   32篇
  2015年   20篇
  2014年   15篇
  2013年   62篇
  2012年   24篇
  2011年   30篇
  2010年   24篇
  2009年   20篇
  2008年   33篇
  2007年   31篇
  2006年   24篇
  2005年   16篇
  2004年   15篇
  2003年   7篇
  2002年   18篇
  2001年   15篇
  2000年   9篇
  1999年   6篇
  1998年   5篇
  1997年   1篇
  1996年   4篇
  1995年   4篇
  1992年   3篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1985年   2篇
  1983年   1篇
排序方式: 共有521条查询结果,搜索用时 15 毫秒
31.
This study analyzes the faunal assemblages corresponding to the Middle and Upper Paleolithic and the Early Epipaleolithic for the central Spanish Mediterranean Region dated from between 135,000 and 9,000 B.P. To interpret these data, we employ a zooarchaeological and paleoeconomic perspective. Human large and small game hunting systems are analyzed through the identification of the origins of faunal assemblages, bone breackage patterns, and prey selection patterns. Our study shows that hunting systems changed significantly through time, which may be related to the characteristics of the Mediterranean ecosystem and, above all, to cultural changes.  相似文献   
32.
New Tremadocian ostracod material from the Alborz Mountains of Iran confirms the early and widespread occurrence of the Ordovician genus Nanopsis, and the apparently simultaneous first appearance of ostracods in the fossil record at the level of the P. deltifer conodont biozone (485.5 Ma) from China to Argentina. Nanopsis pairidaeza sp. nov. adds to the pool of species diversity for the Early Ordovician, though documented Tremadocian ostracod generic diversity remains low, with only four genera. The presence of Early Ordovician ostracods in Alborz, their occurrence elsewhere in palaeocontinental Gondwana, Baltica and China coupled to their marked absence from the Tremadocian of Laurentia and Siberia, supports the notion of the earliest occurrence of ostracods centred on Gondwana/Baltica.  相似文献   
33.
Due to women's increased participation in the labour force, more and more family‐households are now juggling paid labour and care‐giving in space and time and do so in many different ways. Much research and policy about how households try to establish a satisfactory work‐life balance singles out particular coping strategies, such as telecommuting or the mobilizing of informal help by relatives or friends. While insightful, foregrounding single strategies may oversimplify the complex reality of everyday life, in which people often skilfully weave together multiple coping strategies. As well, advances in information and communication technologies (ICTs) have further diversified the arsenal of possible coping strategies, but the academic literature has yet to verify whether ICT usage complements or substitutes the adoption of other coping strategies. Adopting a holistic quantitative approach this study assesses which combinations of coping strategies prevail and which role ICTs play in this regard among one‐ and dual‐earner households in the Utrecht–Amersfoort–Hilversum area of the Netherlands. We also examine systematic variations in strategy combination by socio‐demographics, ICT possession, affordability and skills, social network factors, employment and commute factors, spatial factors, lifestyle orientation and other factors. We identify several distinct combinations of strategies and find that ICT‐related strategies are frequently adopted by highly educated employed parents in the Netherlands attempting to achieve a satisfying work‐life balance and tend to complement other types of strategies. Which combinations of strategies have been adopted depends most strongly on the presence of young children, but also on employment factors and characteristics of the environment surrounding the dwelling and main workplace.  相似文献   
34.
Cryptorhynchia is a brachiopod genus, until recently known only from the late Bathonian. Two new species C. karuna and C. jhooraensis are here described from the middle Bathonian at Kutch, western India and record the earliest known occurrences of the genus. They constitute ancestor-descendant lineages with the two existing younger species C. pulcherrima and C. rugosa respectively. Evolution in both cases shows ‘parallel’ trends and the descendants are scaled-down versions of their respective progenitors. Statistical analyses reveal that this evolutionary miniaturization involves allometry-induced heterochrony, especially progenesis, and is marked by a rapid speciation event compatible with the punctuational model. Evolution appears to be anagenetic and may be attributed to the unstable nature of environment where onshore innovation produced smaller descendants that adopted r-strategy. Facies distribution and functional morphology suggest that species of Cryptorhynchia were well adapted to shallow, unstable carbonate shelf. However, they disappeared suddenly at the Bathonian - Callovian boundary which was marked by a global transgression. The possible causal factors of their extinction may be the consequent changes in bathymetry and substrate condition.  相似文献   
35.
Techniques of production were measured for 18 manufacturing industries across 6 regions of Canada between 1961 and 1988. In any given year, production technology, measured by a pair of capital and labour input coefficients, varies markedly over space. The relative positions of regions in a two-dimensional technology-space appears consistent across industries. With industry-mix effects removed, multivariate analysis of variance confirms that regional differences in production techniques are significant. Further investigation reveals that spatial variations in techniques of production persist over time. These findings support the claims of evolutionary theorists, demonstrating that in Canadian manufacturing industries regions tend to move along distinct trajectories of technological change.
On a mesuré les techniques de production dans 18 industries manufacturières de 6 régions du Canada au cours de la période 1961-88. La technologie de production, mesurée par deux coefficients des entrées du capital et du travail, diffère considérablement d'une région à l'autre à une année donnée. Les positions relatives des régions par rapport aux deux dimensions espace-technologie se maintiennent dans toutes les industries. Si on écarte les effets de la composition industrielle, l'analyse de variance à plusieurs variables démontre qu'il existe d'importantes différences régionales en techniques de production. L'analyse complémentaire révèle que les variations spatiales des techniques de production persistent à travers le temps. Ces résultats confirment la position des théoriciens évolutionnistes à l'effet que dans les industries manufacturières canadiennes, les régions ont tendance à suivre des trajectoires distinctes de changements technologiques.  相似文献   
36.
试论民俗演化与人地关系发展的内在联系   总被引:4,自引:1,他引:3  
马洪元 《人文地理》1992,7(1):18-23
人地关系起人文地理学研究的核心内容。本文通过分析民俗演化与人地关系发展在历史进程、影响因素、区域差异、发展趋向等方面的一致性,探索协调人地关系的新途径及其可行性。  相似文献   
37.
通过对出入西安美加游客的实地调查,利用计算机软件建立数据库进行资料统计分析,探讨西安与其它旅游热点城市之间美加游客空间转移模式及其影响因素,提出美加旅游市场的几点营销策略。  相似文献   
38.
乌兰察布农业企业发展迟缓的原因及其解决对策   总被引:8,自引:0,他引:8  
孟祥林 《人文地理》1999,14(4):63-67
初级农产品经过二次转化后,可以使其价值倍增,很多的农民企业家和当地的政府机关都看重了这块风水宝地,纷纷建起了乡镇企业,对本地的农产品进行消化,以求增值、创税。但是,在乡镇企业发展的过程中,由于流动资金短缺、原材料不足、重复建设等原因,使得众多的乡镇企业发展迟缓,甚至不得不被其他企业兼并或者宣布破产。本文的重点就是要对上述问题存在的原因进行挖掘,并力求给出相应的解决对策。  相似文献   
39.
许浩 《人文地理》2005,20(2):93-97
现代艺术是目前唯一在国际上占统治地位的艺术现象。本文从地理学角度出发研究现代艺术的发展演变。首先回顾了现代艺术的发展过程,重点分析了现代艺术的地域性特征,指出国际现代艺术体系有"中心-边缘"性的分布格局,从流派数量和艺术主题的变化方面总结了其发展演变特点,并且总结了历史上三次重要的艺术扩散过程。其次分析了我国现代艺术发展的时空分布和地理格局,指出我国现代艺术的中心位于东部沿海大城市,具有分布不均、在国际体系中地位不高的特征。最后指出我国城市积极参与国际现代艺术体系、提升文化艺术地位的重要性和途径。  相似文献   
40.
尺度是人文地理学的核心概念。为了深化对尺度的理解,本文详尽梳理了目前西方研究中的尺度认知,从隐喻、实践和认识论角度对尺度进行了理解和定义;在此基础上,基于二次抽象的视角,探讨了尺度的本质含义及其分析框架。本文认为,尺度本质上是对基本地理维度(如地方、网络和领土)的二次抽象,是一种建构的概念,因此讨论尺度真假并无实质意义;另一方面,尺度的划分不单纯是容器,而是与各种社会-权力关系相交织,并被不断重构和利用,从而形成了各种尺度化实践和尺度政治。因此,对尺度的研究和运用更应关注其解释力和影响力。最后,本文基于这一理解,探讨了中国政治文化背景中的尺度概念和尺度政治课题。  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