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   541篇
  免费   15篇
管理学   66篇
民族学   5篇
人口学   61篇
丛书文集   1篇
理论方法论   79篇
综合类   6篇
社会学   283篇
统计学   55篇
  2021年   3篇
  2020年   3篇
  2019年   16篇
  2018年   10篇
  2017年   15篇
  2016年   17篇
  2015年   9篇
  2014年   21篇
  2013年   83篇
  2012年   22篇
  2011年   11篇
  2010年   18篇
  2009年   12篇
  2008年   18篇
  2007年   16篇
  2006年   14篇
  2005年   15篇
  2004年   12篇
  2003年   14篇
  2002年   20篇
  2001年   10篇
  2000年   8篇
  1999年   12篇
  1998年   12篇
  1997年   10篇
  1996年   9篇
  1995年   11篇
  1994年   11篇
  1993年   6篇
  1992年   3篇
  1991年   3篇
  1990年   6篇
  1989年   9篇
  1987年   8篇
  1986年   8篇
  1985年   11篇
  1984年   8篇
  1983年   7篇
  1981年   4篇
  1980年   4篇
  1979年   4篇
  1978年   6篇
  1977年   5篇
  1975年   5篇
  1974年   4篇
  1970年   3篇
  1969年   2篇
  1968年   2篇
  1967年   2篇
  1966年   3篇
排序方式: 共有556条查询结果,搜索用时 15 毫秒
101.
The initial version (v1) of the Fish Invasiveness Scoring Kit (FISK) was adapted from the Weed Risk Assessment of Pheloung, Williams, and Halloy to assess the potential invasiveness of nonnative freshwater fishes in the United Kingdom. Published applications of FISK v1 have been primarily in temperate‐zone countries (Belgium, Belarus, and Japan), so the specificity of this screening tool to that climatic zone was not noted until attempts were made to apply it in peninsular Florida. To remedy this shortcoming, the questions and guidance notes of FISK v1 were reviewed and revised to improve clarity and extend its applicability to broader climatic regions, resulting in changes to 36 of the 49 questions. In addition, upgrades were made to the software architecture of FISK to improve overall computational speed as well as graphical user interface flexibility and friendliness. We demonstrate the process of screening a fish species using FISK v2 in a realistic management scenario by assessing the Barcoo grunter Scortum barcoo (Terapontidae), a species whose management concerns are related to its potential use for aquaponics in Florida. The FISK v2 screening of Barcoo grunter placed the species into the lower range of medium risk (score = 5), suggesting it is a permissible species for use in Florida under current nonnative species regulations. Screening of the Barcoo grunter illustrates the usefulness of FISK v2 as a proactive tool serving to inform risk management decisions, but the low level of confidence associated with the assessment highlighted a dearth of critical information on this species.  相似文献   
102.
The Fish Invasiveness Scoring Kit (FISK) is currently one of the most popular pre‐screening tools for freshwater fishes. A recent upgrade has ensured its wider climatic relevance to countries with subtropical regions. This enhancement is of particular importance to Australia, which encompasses tropical, arid, and temperate zones, and where the introduction of non‐native fish species poses a significant risk to biodiversity. In this study, 55 fish species previously evaluated in a U.K.‐based calibration of FISK are reassessed for their potential invasiveness in the Murray‐Darling Basin (MDB; southeastern Australia), the continent's largest catchment encompassing arid and temperate climates. Approximately half of the species were classed as “medium risk” and the other half as “high risk,” and the ≥19 threshold previously identified from the calibration study was confirmed. The three highest scoring species (common carp Cyprinus carpio carpio, goldfish Carassius auratus, and eastern mosquitofish Gambusia holbrooki) were those already present and invasive in the area, whereas nearly half of the tropical and subtropical species had lower scores compared to U.K. assessments, possibly because of climate change predictions of drier conditions across the MDB. There were some discordances between FISK and two Australian‐based assessment protocols, one of which is qualitative and the other represents a simplified version of FISK. Notably, the Australian origins of FISK should provide for an additional reason for further applications of the tool in other RA areas (i.e., drainage basins) of the continent, ultimately encouraging adoption as the country's reference screening tool for management and conservation purposes.  相似文献   
103.
Risk assessments are crucial for identifying and mitigating impacts from biological invasions. The Fish Invasiveness Scoring Kit (FISK) is a risk identification (screening) tool for freshwater fishes consisting of two subject areas: biogeography/history and biology/ecology. According to the outcomes, species can be classified under particular risk categories. The aim of this study was to apply FISK to the Iberian Peninsula, a Mediterranean climate region highly important for freshwater fish conservation due to a high level of endemism. In total, 89 fish species were assessed by three independent assessors. Results from receiver operating characteristic analysis showed that FISK can discriminate reliably between noninvasive and invasive fishes for Iberia, with a threshold of 20.25, similar to those obtained in several regions around the world. Based on mean scores, no species was categorized as “low risk,” 50 species as “medium risk,” 17 as “moderately high risk,” 11 as “high risk,” and 11 as “very high risk.” The highest scoring species was goldfish Carassius auratus. Mean certainty in response was above the category “mostly certain,” ranging from tinfoil barb Barbonymus schwanenfeldii with the lowest certainty to eastern mosquitofish Gambusia holbrooki with the highest level. Pair‐wise comparison showed significant differences between one assessor and the other two on mean certainty, with these two assessors showing a high coincidence rate for the species categorization. Overall, the results suggest that FISK is a useful and viable tool for assessing risks posed by non‐native fish in the Iberian Peninsula and contributes to a “watch list” in this region.  相似文献   
104.
105.
This paper is a review of research in Chicago that linked analyses of vegetation structure with forest functions and values. During 1991, the regions trees removed an estimated 5575 metric tons of air pollutants, providing air cleansing worth 9.2 million. Each year they sequester an estimated 315 800 metric tons of carbon. Increasing tree cover 10% or planting about three trees per building lot saves annual heating and cooling costs by an estimated 50 to 90 per dwelling unit because of increased shade, lower summertime air temperatures, and reduced neighborhood wind speeds once the trees mature. The net present value of the services trees provide is estimated as 402 per planted tree. The present value of long-term benefits is more than twice the present value of costs.  相似文献   
106.
107.
Dans cette étude, nous examinons les hypothèses des partisans de la «mondialisation>> et proposons des solutions totalement opposées. Dans la première partie, nous réfutons les arguments suivants au sujet de la «mondialisation>>: la souveraineté nationale s'érode dans tous les pays; la part de propriété transnationale est plus importante que par le passé; la «mondialisation>> constitue la conséquence inévitable du changement technologique; et la libéralisation de l'économie à l'échelle mondiale renforce la démocratic Dans la deuxième partie, nous examinons les solutions de rechange démocratiques que peuvent offrir les anciens et les nouveaux mouvements sociaux. L'utilisation de fonds d'investissement gérés par le public et engagés selon les besoins des collectivités est considérée comme une solution de rechange à l'orientation axée sur le marché mondial des entreprises transnationales.
This paper critically examines the assumptions of the advocates of "globalization" and develops an alternative that is the polar opposite. The first half of the paper challenges the following assumptions about "globalization": that national sovereignty is eroding for all countries; that the level of transnational ownership is higher now than in the past; that "globalization" has been the inevitable result of technological change; that democracy is strengthened by global economic liberalization. The second half of the paper examines the prospects for the creation of democratic alternatives to globalization in old and new social movements. Socially controlled investment funds that have "location commitment" to communities are seen as an alternative to the globalization vision of transnational corporations.  相似文献   
108.
The political influence of unions and corporations is examined by analyzing Senate roll-call votes on COPE-identified legislation for the period 1979–1988. Union PAC contributions and union membership both have significant positive effects on three different types of COPE legislation: Narrow Union, General Labor, and Non-Labor. In addition, corporate PAC contributions to senators’ opponents reduce their pro-union voting behavior on Narrow Union and General Labor bills. There is no evidence that the political influence of unions in the U.S. is declining.  相似文献   
109.
A study of gambling among juveniles in the United Kingdom reveals that their favorite form of gambling, both in terms of percent participating and amounts spent, is playing Amusement with Prizes (i.e., slot) machines. These machines are widely, freely, and legally available to persons of all ages at amusement arcades, youth clubs, cafes, sports centers, bus and railroad stations, and other public settings. Before 1980, machine gamblers were rare at Gamblers Anonymous meetings. However, since that time, their numbers have increased rapidly, currently representing about half of all new members. Of these, 50% are described as children with the remainder in their late teens or early 20s.The balance of the paper describes the difficulties faced by the parents of these youth and the recent development and objectives of a unique self-help group called Parents of Young Gamblers.Editor's Note: Since this writing, P.O.Y.G. has channeled their energies into lobbying the Home Office to take action that would recognize slot machines as gambling devices, remove them from their present easy access to children, and restrict their availability to licensed Game Clubs where only registered adult members may play. The Home Office recently has agreed to place this matter under consideration.The Reverend Gordon E. Moody, M.B.E., was Secretary of the late (British) Churches' Council on Gambling. In the United Kingdom he is Honorary Founder-Patron of Gamblers Anonymous and Chairman of the Gamblers Anonymous General Services Board. He is Founder of Gordon House (a hostel for single, homeless compulsive gamblers) and Honorary Life Member of the Society for the Study of Gambling.  相似文献   
110.
The validity and use of the family-of-origin scale   总被引:1,自引:0,他引:1  
This study explores the Family-of-Origin Scale (FOS) with regard to its validity and potential use. Subjects included 100 adults currently in psychotherapy, 100 who were not, 32 who previously had sought treatment, and 41 college students. Between-group comparisons, correlations with both the 16PF and a scale of authoritarianism, factor analyses of both the patient and nonpatient FOS responses, and a review of patient feedback revealed several significant results. The FOS differentiates between patients and nonpatients, but it measures only one general factor and delivers little information. Therefore, it has little value as a research instrument, but it may be a useful adjunct to psychotherapy in individual cases.  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