全文获取类型
收费全文 | 12495篇 |
免费 | 253篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1881篇 |
民族学 | 74篇 |
人才学 | 1篇 |
人口学 | 1163篇 |
丛书文集 | 54篇 |
理论方法论 | 1265篇 |
综合类 | 163篇 |
社会学 | 6126篇 |
统计学 | 2022篇 |
出版年
2023年 | 85篇 |
2021年 | 70篇 |
2020年 | 196篇 |
2019年 | 297篇 |
2018年 | 312篇 |
2017年 | 457篇 |
2016年 | 326篇 |
2015年 | 265篇 |
2014年 | 310篇 |
2013年 | 2126篇 |
2012年 | 432篇 |
2011年 | 447篇 |
2010年 | 311篇 |
2009年 | 276篇 |
2008年 | 302篇 |
2007年 | 330篇 |
2006年 | 339篇 |
2005年 | 310篇 |
2004年 | 308篇 |
2003年 | 262篇 |
2002年 | 294篇 |
2001年 | 287篇 |
2000年 | 263篇 |
1999年 | 261篇 |
1998年 | 201篇 |
1997年 | 202篇 |
1996年 | 179篇 |
1995年 | 159篇 |
1994年 | 151篇 |
1993年 | 171篇 |
1992年 | 169篇 |
1991年 | 175篇 |
1990年 | 175篇 |
1989年 | 193篇 |
1988年 | 135篇 |
1987年 | 146篇 |
1986年 | 132篇 |
1985年 | 145篇 |
1984年 | 148篇 |
1983年 | 139篇 |
1982年 | 122篇 |
1981年 | 117篇 |
1980年 | 113篇 |
1979年 | 113篇 |
1978年 | 108篇 |
1977年 | 80篇 |
1976年 | 81篇 |
1975年 | 81篇 |
1974年 | 72篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Michael Rodriguez 《Serials Review》2020,46(2):150-156
AbstractAccessibility of library electronic resources is a must. Its importance derives from professional ethics of librarianship, rising total costs of acquisition, and mounting legal challenges to colleges and universities that fail to provide resources accessible to users with disabilities. Library staff are responsible for ensuring the accessibility of vendor-licensed eresources. This column reviews the accessibility clauses of nine model license agreements for electronic resources. It describes terms that should go into an optimal accessibility clause and creates a composite model clause. It also provides guidance for library staff seeking to negotiate stronger accessibility language into vendor license agreements. Finally, it addresses the impact of accommodation requests on the total cost of acquiring library eresources, concluding with a call to redouble efforts to advocate for greater accessibility and educate both vendors and library staff about its importance. 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
Michael P. Fay Ji-Hyun Lee 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2006,169(1):81-96
Summary. We detail a general method for measuring agreement between two statistics. An application is two ratios of directly standardized rates which differ only by the choice of the standard. If the statistics have a high value for the coefficient of agreement then the expected squared difference between the statistics is small relative to the variance of the average of the two statistics, and inferences vary little by changing statistics. The estimation of a coefficient of agreement between two statistics is not straightforward because there is only one pair of observed values, each statistic calculated from the data. We introduce estimators of the coefficient of agreement for two statistics and discuss their use, especially as applied to functions of standardized rates. 相似文献
10.
Diane Hope Weixing Zhu Corinna Gries Jacob Oleson Jason Kaye Nancy B. Grimm Lawrence A. Baker 《Urban Ecosystems》2005,8(3-4):251-273
We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding
desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well
as for the desert and urban sites separately. Concentrations of both NO3-N and NH4-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO3-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious
surfaces and lawn, whereas soil NH4-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO3-N and NH4-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation
of soil NO3-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic
soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than
factors related to an urban-rural gradient. 相似文献