全文获取类型
收费全文 | 63016篇 |
免费 | 1709篇 |
国内免费 | 745篇 |
专业分类
管理学 | 1985篇 |
劳动科学 | 9篇 |
民族学 | 905篇 |
人才学 | 13篇 |
人口学 | 744篇 |
丛书文集 | 7879篇 |
理论方法论 | 2457篇 |
综合类 | 45405篇 |
社会学 | 3309篇 |
统计学 | 2764篇 |
出版年
2024年 | 117篇 |
2023年 | 399篇 |
2022年 | 504篇 |
2021年 | 644篇 |
2020年 | 839篇 |
2019年 | 857篇 |
2018年 | 798篇 |
2017年 | 996篇 |
2016年 | 1024篇 |
2015年 | 1299篇 |
2014年 | 3143篇 |
2013年 | 4253篇 |
2012年 | 4016篇 |
2011年 | 4560篇 |
2010年 | 3651篇 |
2009年 | 3738篇 |
2008年 | 3889篇 |
2007年 | 4696篇 |
2006年 | 4682篇 |
2005年 | 4194篇 |
2004年 | 3899篇 |
2003年 | 3861篇 |
2002年 | 3182篇 |
2001年 | 2703篇 |
2000年 | 1469篇 |
1999年 | 462篇 |
1998年 | 274篇 |
1997年 | 201篇 |
1996年 | 176篇 |
1995年 | 131篇 |
1994年 | 93篇 |
1993年 | 109篇 |
1992年 | 85篇 |
1991年 | 85篇 |
1990年 | 41篇 |
1989年 | 77篇 |
1988年 | 22篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 30篇 |
1984年 | 67篇 |
1983年 | 39篇 |
1982年 | 41篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1978年 | 15篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Emma Hartnett Amie Adkin Miles Seaman John Cooper Eamon Watson Helen Coburn Tracey England Christophen Marooney Anthony Cox Mavion Wooldridge 《Risk analysis》2007,27(1):187-202
Foot and mouth disease (FMD) is considered by many as the most important animal disease in the world. FMD is highly contagious and outbreaks incur significant costs as affected countries are severely limited in their ability to trade. A number of trade commodities may be contaminated with FMD virus (FMDV) including animal products, for example, meat. As a member of the European Union, Great Britain (GB) has put in place a number of regulations to prevent the importation of pathogens in imported meat products. However, the illegal importation of meat provides a route by which safety controls may be circumvented and meat from FMD affected areas may be imported. This study assesses the FMD infection risk posed to the livestock population of GB from the illegal importation of meat, and estimates the major contributors to this overall risk, through the development of a quantitative risk assessment model. From model results, the total amount of illegal meat entering GB each year is estimated on average to be 11,875 tonnes. with 90% certainty that this is between 4,398 and 28,626 tonnes per year; of which between 64.5 and 565 kg are contaminated with FMDV. This flow of illegal meat results in an estimate of a frequency of FMD infection in GB livestock of 0.015 cases of infected animals per year, with 90% certainty it is between 0.0017 and 0.053. Imports from the region Near and Middle East account for 47% of this risk, and 68% of the risk is attributed to bone-in and dried de-boned products. 相似文献
22.
The benchmark dose (BMD) is an exposure level that would induce a small risk increase (BMR level) above the background. The BMD approach to deriving a reference dose for risk assessment of noncancer effects is advantageous in that the estimate of BMD is not restricted to experimental doses and utilizes most available dose-response information. To quantify statistical uncertainty of a BMD estimate, we often calculate and report its lower confidence limit (i.e., BMDL), and may even consider it as a more conservative alternative to BMD itself. Computation of BMDL may involve normal confidence limits to BMD in conjunction with the delta method. Therefore, factors, such as small sample size and nonlinearity in model parameters, can affect the performance of the delta method BMDL, and alternative methods are useful. In this article, we propose a bootstrap method to estimate BMDL utilizing a scheme that consists of a resampling of residuals after model fitting and a one-step formula for parameter estimation. We illustrate the method with clustered binary data from developmental toxicity experiments. Our analysis shows that with moderately elevated dose-response data, the distribution of BMD estimator tends to be left-skewed and bootstrap BMDL s are smaller than the delta method BMDL s on average, hence quantifying risk more conservatively. Statistically, the bootstrap BMDL quantifies the uncertainty of the true BMD more honestly than the delta method BMDL as its coverage probability is closer to the nominal level than that of delta method BMDL. We find that BMD and BMDL estimates are generally insensitive to model choices provided that the models fit the data comparably well near the region of BMD. Our analysis also suggests that, in the presence of a significant and moderately strong dose-response relationship, the developmental toxicity experiments under the standard protocol support dose-response assessment at 5% BMR for BMD and 95% confidence level for BMDL. 相似文献
23.
Since children, particularly daughters, are among the most important sources of help and support for older Americans, it has been suggested that women's increasing employment will affect filial relations. Empirical evidence on this issue is inconsistent, in part due to the use of nonprobability samples. Few studies have measured effects for men. We attempt to broaden the scope of this question beyond help to the frail elderly by asking whether employment affects filial relations in general. We examine effects of hours employed on telephone contact, visiting, feelings of closeness, filial attitudes, and assistance to biological parents, for an area probability sample of men and women over 40. There are no effects of employment for men or women on contact, closeness, or assistance. For the vast majority of this population sample, contact and assistance involve few hours per week, and thus do not seem to conflict with employment. 相似文献
24.
25.
Barbara Pocock 《Gender, Work and Organization》2005,12(1):32-49
Increasingly around the industrialized world, labour markets rely upon the paid work of women, many of whom have dependents. Such changing patterns of paid work by women — and by men — are located within work/care regimes that are more or less hostile to the needs of paid workers who care for others. This article sets out a model of work/care regimes and locates the Australian case within international and historical contexts. In Australia, the unchanging normative male worker archetype dominates institutions of work and care, while the cultures of motherhood and fatherhood remain stoically resistant to renovation. In the meantime, the behaviour of working women runs ahead of these unchanging cultures and institutions, creating a policy interest in ‘reconciling’ work and care, but a failure to provide it. The reasons for this failure are outlined. 相似文献
26.
Mayer N. Zald 《Sociological Forum》1995,10(3):455-479
What do we mean by progress and cumulation in the social and human sciences? Recent thinking in the philosophy and history of science has led to an abandonment of some versions of logical positivism and of verificationism that had a strong deductive and theory testing orientation. What is to replace them is less clear. This paper argues that progress and cumulation can be seen as a process of evaluation and retention within an epistemic community. Scholarly disciplines differ in their social structure and in their epistemic and normative commitments. Since sociology is a fragmented discipline, progress and cumulation differ within its multiple subdisciplines, which to varying extents represent epistemic communities. Brief sketches of progress (advance) and cumulation in several subdisciplines are offered. 相似文献
27.
作者运用理论分析和实证分析相结合的方法对佛山市经济发展的实践予以深刻剖视后指出:佛山市经济建设处在从物质投入主导型向科技进步主导塑转变的转折点上,在跨世纪的经济发展与经济竞争中,佛山市必须实行科技兴市的新发展战略,作者对佛山市科技兴市战略的涵义,目标,条件作了深入分析,并进而设计了科技兴市战略的运行机制和政策落点。 相似文献
28.
Hilary Parsons Dick 《Qualitative sociology》2006,29(1):87-102
When a researcher enters an interview, she has already construed it as being a standard type of communicative event. This
article considers how a researcher's construal of a communicative event as either an ethnographic or survey interview shapes
the production of information. Interview standards entail epistemological assumptions that directly inform the type of information
sought and produced. I consider this process through a comparison of the elicitation techniques I employed in survey and ethnographic
interviews conducted during research in Mexico. I draw on theory in linguistic anthropology on the nature of meaning in language,
examining how dialogicality and interaction are essential to understanding the construal of communicative events. 相似文献
29.
1917年京直水灾与赈济情况略述 总被引:1,自引:0,他引:1
1917年,京直地区出现了数十年未遇的大水灾,一百多个县被淹,几百万人口受灾,灾情十分严重。水灾发生后,北洋政府和社会各界予以高度重视,施行了一系列赈灾措施,使灾民的困苦得到一定程度的缓解。但是,在赈灾过程中也存在着不少的弊端,使赈灾效果大打折扣,这是由当时的社会政治环境所造成的。 相似文献
30.
Current status data arise when the death of every subject in a study cannot be determined precisely, but is known only to have occurred before or after a random monitoring time. The authors discuss the analysis of such data under semiparametric linear transformation models for which they propose a general inference procedure based on estimating functions. They determine the properties of the estimates they propose for the regression parameters of the model and illustrate their technique using tumorigenicity data. 相似文献