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   13463篇
  免费   377篇
管理学   1747篇
民族学   62篇
人才学   1篇
人口学   1057篇
丛书文集   72篇
教育普及   3篇
理论方法论   1273篇
综合类   124篇
社会学   7257篇
统计学   2244篇
  2023年   72篇
  2021年   75篇
  2020年   174篇
  2019年   265篇
  2018年   290篇
  2017年   414篇
  2016年   311篇
  2015年   229篇
  2014年   332篇
  2013年   2657篇
  2012年   365篇
  2011年   365篇
  2010年   303篇
  2009年   270篇
  2008年   309篇
  2007年   309篇
  2006年   327篇
  2005年   286篇
  2004年   252篇
  2003年   231篇
  2002年   251篇
  2001年   331篇
  2000年   300篇
  1999年   313篇
  1998年   210篇
  1997年   201篇
  1996年   233篇
  1995年   245篇
  1994年   243篇
  1993年   248篇
  1992年   253篇
  1991年   249篇
  1990年   259篇
  1989年   221篇
  1988年   210篇
  1987年   185篇
  1986年   174篇
  1985年   187篇
  1984年   196篇
  1983年   141篇
  1982年   140篇
  1981年   111篇
  1980年   123篇
  1979年   122篇
  1978年   101篇
  1977年   92篇
  1976年   89篇
  1975年   90篇
  1974年   60篇
  1973年   55篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
851.
Suicide, the endpoint of a continuum that begins with suicide ideation, is the third leading cause of death among the US college-aged population. The first and second leading causes of death among this age group, unintentional injury and homicide, may also be linked to suicide ideation. We used data from the National College Health Risk Behavior Survey to examine the association between suicide ideation and injury-related behaviors among 18- to 24-year-old college students. Students who reported suicide ideation were significantly more likely than students who did not report considering suicide to carry a weapon, engage in a physical fight, boat or swim after drinking alcohol, ride with a driver who had been drinking alcohol, drive after drinking alcohol, and rarely or never used seat belts. Given this clustering of injury-related risk behaviors, college prevention programs should aim to reduce risks for injuries comprehensively, rather than addressing each risk behavior separately.  相似文献   
852.
This study evaluates airborne concentrations of common trihalomethane (THM) compounds in bathrooms during showering and bathing in homes supplied with chlorinated tap water. Three homes in an urban area were selected, each having three bedrooms, a full bath, and approximately 1,000 square feet of living area. THMs were concurrently measured in tap water and air in the shower/bath enclosure and the bathroom vanity area using Summa canisters. Chloroform (TCM), bromodichloromethane (BDCM), and chlorodibromomethane (CDBM) were quantified using U.S. Environmental Protection Agency (EPA) Method TO-14. Air samples were collected prior to, during, and after the water-use event for 16 shower and 7 bath events. Flow rate and temperature were measured, but not controlled. The increase in average airborne concentration (+/- standard error) during showers (expressed as microg/m3 in shower enclosure or bathroom air per microg/L in water) was 3.3+/-0.4 for TCM, 1.8+/-0.3 for BDCM, and 0.5+/-0.1 for CDBM (n = 12), and during baths was 1.2+/-0.4 for TCM, 0.59+/-0.21 for BDCM, and 0.15+/-0.05 for CDBM (n = 4). The relative contribution of each chemical to the airborne concentrations was consistent for all shower and bath events, with apparent release of TCM > BDCM > CDBM. The results are therefore consistent with their relative concentration in tap water and their vapor pressures. When the shower findings for TCM are normalized for water concentration, flow rate, shower volume, and duration, the average exposure concentrations in these urban residences are about 30% lower than those reported by other investigators using EPA analytical methods. This difference is likely attributable primarily to greater air exchange rates in residential shower/bath stalls compared to more "airtight" laboratory shower chambers. This appears to be the first field study to thoroughly evaluate THM exposures from residential showers and baths, and can be used to validate previously published models of tap water volatile chemical transfer to indoor air.  相似文献   
853.
Very few demographic surveys in developing countries have gathered information on household incomes or consumption expenditures. Researchers interested in living standards therefore have had little alternative but to rely on simple proxy indicators. The properties of these proxies have not been analyzed systematically. We ask what hypotheses can be tested using proxies, and compare these indicators with consumption expenditures per adult, our preferred measure of living standards. We find that the proxies employed in much demographic research are very weak predictors of consumption per adult. Nevertheless, hypothesis tests based on proxies are likely to be powerful enough to warrant consideration.  相似文献   
854.
Effective and cost efficient work injury prevention and disability management requires an integrated process that involves a number of components. Each component needs to be linked into a continuum or system. Components by themselves will not provide satisfactory solutions. This article addresses some of the key components that need to be included in an effective work injury management system. The goals of a management system are discussed and how each component plays a part in achieving these goals.  相似文献   
855.
The three sociological conceptions of community are outlined: the imagined community, community as friendship, and community as local organizations or groups. The extent to which gay men in New York City experience a gay community in each of these ways is investigated by means of in-depth interviews. The type of moral discourse utilized by the gay men interviewed is also discussed. Finally, gay men in New York City are compared to the new Russian Jewish community in Brooklyn as to which is more "postmodern."  相似文献   
856.
Siting Noxious Facilities: A Test of the Facility Siting Credo   总被引:2,自引:0,他引:2  
Over the past decade it has become increasingly difficult to site noxious facilities, despite the fact that there is a growing need to do so. To address this problem, a set of guidelines for a fairer, wiser, and more workable siting process—the Facility Siting Credo—was developed during a National Facility Siting Workshop in 1990. This paper presents an empirical test of these guidelines. A questionnaire based on the Credo was completed by stakeholders in 29 waste facility siting cases, both successful and unsuccessful, across the United States and Canada. Using an independent determination of outcome (success), a preliminary ranking of the importance of various Credo principles was obtained. The data reveal that establishing trust between the developer and host community is an important factor in facilitating the siting process. The siting process is most likely to be successful when the community perceives the facility design to be appropriate and to satisfy its needs. Public participation also is seen to be an important process variable, particularly if it encourages a view that the facility best meets community needs. Moreover, a siting process where communities volunteer to host facilities is an approach that holds promise for meeting many of these key success criteria.  相似文献   
857.
A Bayesian Benefit-Risk Model Applied to the South Florida Building Code   总被引:1,自引:0,他引:1  
A Bayesian compound Poisson benefit-risk model is described in this paper, and used to evaluate recent revisions to the South Florida Building Code (SFBC). The model accounts for natural variability in hurricane frequency and severity, and uncertainty in the effectiveness of the revised code. Ranges of residential growth rate, code effectiveness, construction cost increase, and planning period length are assumed, to show the ranges of cost-to-performance ratio within which the code will make sense economically. The expected cost of residential hurricane damage over 50 years for ten South Florida counties assuming continuation of previous building practices was $93 billion, equivalent to the residential damage of 5.2 Andrews. Assuming a reduction in the growth of damageable housing in South Florida from 5.5% to 2% as a result of code revision, estimated damages under the new code were $45 billion. At a per-house construction cost increase of 5%, the probability of at least recovering the estimated $40 billion cost of the specified wind-resistant construction was estimated to be 47%. Expected return on investment was estimated at $7 billion over 50 years. The expected return lies between a $44 billion loss and a $47 billion gain, when growth in damageable housing is allowed to range from 1% to 4% and construction cost increases are assumed to lie between 3% and 8%. Actual monetary return for a 5% cost increase and 2% growth in damageable housing ranges from a $20 billion loss to a $100 billion gain with 95% probability, as a result of weather variability alone. Results support SFBC revisions on solely economic grounds, a conclusion strengthened considerably in light of potentially avoided deaths and hurricane traumas. The model represents one approach to evaluating economic aspects of the sustainability of new technological measures on the basis of available information.  相似文献   
858.
Trust in risk information about food related-hazards may be an important determinant of public reactions to risk information. One of the central questions addressed by the risk communication literature is why some individuals and organizations are trusted as sources of risk information and others are not. Industry and government often lack public trust, whereas other sources (for example, consumer organizations, the quality media, medical doctors) are highly trusted. Problematically, previous surveys and questionnaire studies have utilized questions generated by the investigators themselves to assess public perceptions of trust in different sources. Furthermore, no account of the hazard domain was made. In the first study reported here, semistructured interviewing was used to elicit underpinning constructs determining trust and distrust in different sources providing food-related risk information ( n = 35). In the second study, the repertory grid method was used to elicit the terminology that respondents use to distinguish between different potential food-related information sources ( n = 35), the data being submitted to generalised Procrustes analysis. The results of the two studies were combined and validated in survey research ( n = 888) where factor analysis indicated that knowledge in itself does not lead to trust, but that trusted sources are seen to be characterised by multiple positive attributes. Contrary to previous research, complete freedom does not lead to trust—rather sources which possess moderate accountability are seen to be the most trusted.  相似文献   
859.
The project reported in this article aimed to discover how well the needs of women were being met with respect to rural development and to identify the best approaches to communicating information to farmers in Tanzania. Semi-structured interviews of male and female respondents in selected 200 households in Shinyanga, northwestern Tanzania, were conducted. The interviews were conducted in order to record data on gender differences in farming and herding with the aim of determining how to communicate information on development. Findings showed that women continued to be the poorest group in the community. Use of introduced technology was mostly associated with men's work. The activities of Hifadhi Ardhi Shinyanga conducted through communication channels were also more accessible to men than women. The improved stoves specifically aimed at women also failed because of ineffective communication strategies. It is difficult to approach women because they tend to be tied far more closely to the area of their homes. Thus, training through village workshops would encourage the active participation of women. This would enable information to be shared with, and between, as many women as possible.  相似文献   
860.
This study outlines the results of the UK's national gambling helpline run by GamCare. The results outlined here cover the period of the first 12 months of operation (November 1997 to October 1998). The helpline received a total of 1729 calls. Of these, 51% were from problem gamblers themselves (90% male; 10% female) and a further 26% of calls were from relatives of problem gamblers. The remaining calls came from other professionals handling problem gambling cases (13%), attempted calls, e.g., people calling and then putting the phone down due to being scared of talking (4%), information requests (3%) and the media (3%). Fruit machine gambling appeared to be most problematic for the callers as a whole and for particular sub-groups such as adolescents (82%) and women (52%).  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