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   1065篇
  免费   35篇
管理学   186篇
民族学   4篇
人口学   87篇
丛书文集   7篇
理论方法论   106篇
综合类   10篇
社会学   558篇
统计学   142篇
  2023年   10篇
  2021年   4篇
  2020年   18篇
  2019年   12篇
  2018年   23篇
  2017年   32篇
  2016年   24篇
  2015年   20篇
  2014年   31篇
  2013年   265篇
  2012年   33篇
  2011年   27篇
  2010年   25篇
  2009年   38篇
  2008年   26篇
  2007年   24篇
  2006年   30篇
  2005年   35篇
  2004年   32篇
  2003年   16篇
  2002年   23篇
  2001年   28篇
  2000年   23篇
  1999年   16篇
  1998年   13篇
  1997年   21篇
  1996年   19篇
  1995年   4篇
  1994年   13篇
  1993年   10篇
  1992年   14篇
  1991年   17篇
  1990年   14篇
  1989年   6篇
  1988年   9篇
  1987年   14篇
  1986年   17篇
  1985年   8篇
  1984年   12篇
  1983年   9篇
  1982年   9篇
  1980年   9篇
  1979年   9篇
  1978年   9篇
  1977年   6篇
  1976年   5篇
  1975年   5篇
  1974年   6篇
  1969年   4篇
  1963年   3篇
排序方式: 共有1100条查询结果,搜索用时 31 毫秒
51.
How can we best allocate limited defensive resources to reduce terrorism risks? Dillon et al.'s Antiterrorism Risk-Based Decision Aid (ARDA) system provides a useful point of departure for addressing this crucial question by exhibiting a real-world system that calculates risk reduction scores for different portfolios of risk-reducing countermeasures and using them to rank-order different possible risk mitigation alternatives for Navy facilities. This comment points out some potential limitations of any scoring system that does not take into account risk externalities, interdependencies among threats, uncertainties that are correlated across targets, and attacker responses to alternative allocations of defensive resources. In at least some simple situations, allocations based on risk reduction scores and comparisons can inadvertently increase risks by providing intelligent attackers with valuable information, or they can fail to reduce risks as effectively as nonscoring, optimization-based approaches. These limitations of present scoring methods present exciting technical challenges and opportunities for risk analysts to develop improved methods for protecting facilities and infrastructure against terrorist threats.  相似文献   
52.
53.
54.
Objective. This article uses Cox proportional hazards models to explain departures from the U.S. Courts of Appeals from 1954–2004. I argue that reforms to pension eligibility and financial incentives in 1984 extended opportunities for voluntary departures and strategic behavior, and that reasons for quitting (whether political, personal, or institutional) differed among types of departures and over time. Methods. The data represent all judge‐years from 1954–2004. Both the full period and 1954–1983 and 1984–2004 subperiods are examined. Results. The effects of political factors are limited to partial retirements and suggest judges' recognition of contentious confirmation politics since the 1980s. Personal and institutional variables dominate outright departures. Conclusions. Explanations for departures from the circuit bench differ both by type and over time. Scholars and policymakers should refine arguments regarding judicial turnover and its causes.  相似文献   
55.
Abstract We argue that attempts to superimpose park regulatory regimes on existing land uses in the tropics represent conflicts between alternative cultural models of natural resource management. The results of such conflicts are unique regulatory regimes emerging from distinctive processes that redefine the terms and limits of natural resource use. In creating a scarcity of available resources, parks encourage social differentiation and greater awareness of societal patterns of inequality, establishing a potential for the articulation of demands for social and environmental equity. We evaluate these claims with a case study of the Cerro Azul Meambar National Park in Honduras. We base our analysis on 54 indepth interviews of Park residents in five Park communities.  相似文献   
56.
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   
57.

Most research relating objective indicators of the quality of environment to subjective indicators of the quality of life has failed to find a relationship between the two. This research, by using community data, establishes an association between the local environment and perceived life quality, and in doing so, provides empirical support for focusing on local as welt as national investigations of life quality.  相似文献   
58.
If a specific biological mechanism could be determined by which a carcinogen increases lung cancer risk, how might this knowledge be used to improve risk assessment? To explore this issue, we assume (perhaps incorrectly) that arsenic in cigarette smoke increases lung cancer risk by hypermethylating the promoter region of gene p16INK4a, leading to a more rapid entry of altered (initiated) cells into a clonal expansion phase. The potential impact on lung cancer of removing arsenic is then quantified using a three‐stage version of a multistage clonal expansion (MSCE) model. This refines the usual two‐stage clonal expansion (TSCE) model of carcinogenesis by resolving its intermediate or “initiated” cell compartment into two subcompartments, representing experimentally observed “patch” and “field” cells. This refinement allows p16 methylation effects to be represented as speeding transitions of cells from the patch state to the clonally expanding field state. Given these assumptions, removing arsenic might greatly reduce the number of nonsmall cell lung cancer cells (NSCLCs) produced in smokers, by up to two‐thirds, depending on the fraction (between 0 and 1) of the smoking‐induced increase in the patch‐to‐field transition rate prevented if arsenic were removed. At present, this fraction is unknown (and could be as low as zero), but the possibility that it could be high (close to 1) cannot be ruled out without further data.  相似文献   
59.
60.
Salem Village, both before and through the witchcraft trials, was a religion-based community, allowing its minister to exert a level of political–economic control over its citizens. During the height of the witchcraft episode, there was an increased demand for ministerial services (salvation) in the Salem area. Recent research has argued that the minister used the witchcraft episode to maintain and build upon personal and corporate wealth. In the years after the witchcraft trials changes were made in the business and legal environment of the surrounding New England region. By transitioning to a more neutral rules system with a larger area of consensus for the system, Salem and the rest of the New England transitioned from the 17th Century traditional, religion-based community to a more rules-based, pro-business one in the 18th Century.  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