全文获取类型
收费全文 | 18401篇 |
免费 | 325篇 |
专业分类
管理学 | 2170篇 |
民族学 | 101篇 |
人才学 | 6篇 |
人口学 | 1727篇 |
丛书文集 | 106篇 |
教育普及 | 2篇 |
理论方法论 | 1675篇 |
现状及发展 | 1篇 |
综合类 | 234篇 |
社会学 | 9130篇 |
统计学 | 3574篇 |
出版年
2023年 | 91篇 |
2022年 | 77篇 |
2021年 | 92篇 |
2020年 | 281篇 |
2019年 | 451篇 |
2018年 | 454篇 |
2017年 | 635篇 |
2016年 | 448篇 |
2015年 | 350篇 |
2014年 | 428篇 |
2013年 | 3101篇 |
2012年 | 650篇 |
2011年 | 567篇 |
2010年 | 455篇 |
2009年 | 428篇 |
2008年 | 489篇 |
2007年 | 491篇 |
2006年 | 454篇 |
2005年 | 413篇 |
2004年 | 410篇 |
2003年 | 382篇 |
2002年 | 384篇 |
2001年 | 464篇 |
2000年 | 382篇 |
1999年 | 375篇 |
1998年 | 307篇 |
1997年 | 278篇 |
1996年 | 286篇 |
1995年 | 272篇 |
1994年 | 257篇 |
1993年 | 248篇 |
1992年 | 289篇 |
1991年 | 287篇 |
1990年 | 258篇 |
1989年 | 257篇 |
1988年 | 243篇 |
1987年 | 226篇 |
1986年 | 218篇 |
1985年 | 246篇 |
1984年 | 234篇 |
1983年 | 233篇 |
1982年 | 177篇 |
1981年 | 155篇 |
1980年 | 170篇 |
1979年 | 169篇 |
1978年 | 141篇 |
1977年 | 140篇 |
1976年 | 122篇 |
1975年 | 115篇 |
1974年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Urban forest cover of the Chicago region and its relation to household density and income 总被引:12,自引:0,他引:12
Urban forests and herbaceous open space play a vital role in the environmental and aesthetic health of cities, yet they are rarely identified in land-use inventories of urban areas. To provide information on urban forests and other vegetative land cover in Illinois cities, Landsat Thematic Mapper (TM) data from June 27, 1988, were classified for the Chicago metropolitan region (9,717 km2). Ten land-cover classes were identified, including two types of forestland (occupying 5.8% of the total area), residential land with trees (14.6%) or without trees (7.8%), cropland (37.5%), two types of grassland (7.7%), urban with impervious surfaces (23.1%), water (1.6%), and miscellaneous vegetation (2.1%). Correlation analyses indicated that household income and household density are strongly related to land covers in the region, particularly those with tree cover and urbanized land. Population changes for 1980–1985 and 1985–2010 (projected) show a pattern of increasing density in the urbanized zone concurrent with continued urban sprawl, primarily into current cropland. 相似文献
992.
This article argues that looking solely for the immediate causes of reproductive change may distort our understanding of policy options by failing to take into account the historical and cultural factors that affect not only the impact of policies and programs but their very nature and existence. The article examines the historical origins and spread of “modern” ideas in Bangladesh and the state of West Bengal in India. It concludes that a colonial history in which education and modernization processes took hold very early among the elites in the larger Bengal region was paradoxically accompanied by a strong allegiance to the Bengali language. This strong sense of language identity has facilitated and reinforced the diffusion of modern ideas both within and between the two Bengali‐speaking regions. Thus, to understand the fertility decline in Bangladesh, for example, one needs to look also at cultural boundaries. In this case, the cultural commonality through language facilitates the spread of new ideas across the two Bengals. In turn, the strong sense of language identity has facilitated mass mobilization more easily and intensely within the two Bengals. Shaped by these processes, Bangladesh and West Bengal today are more amenable to social change than many other parts of South Asia and the Middle East. 相似文献
993.
The improvement of product and service quality has been widely discussed in the literature as an appropriate competitive strategy for achieving sustainable competitive advantage. However, neither the linkage between competitive strategy and quality, nor the role of marketing in the implementation of quality-based competitive strategy, has received detailed attention in the marketing and strategy literatures. This paper explores the interface between marketing and quality management in seller organizations, by developing a contingency model of quality strategy. This model is grounded in the literatures of marketing, strategy and quality management, and the perceptions of managers uncovered in exploratory interviews. 相似文献
994.
Mlonte Carlo Techniques for Quantitative Uncertainty Analysis in Public Health Risk Assessments 总被引:2,自引:0,他引:2
Most public health risk assessments assume and combine a series of average, conservative, and worst-case values to derive a conservative point estimate of risk. This procedure has major limitations. This paper demonstrates a new methodology for extended uncertainty analyses in public health risk assessments using Monte Carlo techniques. The extended method begins as do some conventional methods--with the preparation of a spreadsheet to estimate exposure and risk. This method, however, continues by modeling key inputs as random variables described by probability density functions (PDFs). Overall, the technique provides a quantitative way to estimate the probability distributions for exposure and health risks within the validity of the model used. As an example, this paper presents a simplified case study for children playing in soils contaminated with benzene and benzo(a)pyrene (BaP). 相似文献
995.
This study replicates, refines, cross-validates and simplifies a scheme of operationalization and measurement of environmental dimensions proposed by Dess and Beard (1984). Employing a sample of 60 industries and data over a 16-year period, this study found considerable support for the viability of the three dimensions of munificence, dynamism and complexity. The data intensive and computationally complex operationalization scheme was simplified using a discriminant analysis approach and the discriminant functions were cross-validated using an alternate data set. 相似文献
996.
This article extends the debate begun in the June 1992 issue of EMJ when the authors first criticized Michael Porter's explanatory framework in his Competitive Advantage of Nations (1990), over the role of national culture on the competitive advantage of nations. In this paper, Frans van den Bosch and Arno van Prooijen stress that Europe is a locus of competitive advantage if one is prepared to pay attention to the possibility of ‘European Management’ as a potential asset of European firms. In this connection, the transnationalization of European firms is of importance. 相似文献
997.
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
998.
Whitehead A 《Gender and development》1999,7(3):49-61
This paper examines how work and the labor in agriculture in rural sub-Saharan Africa is measured. Section 1 presents a historical example of colonial discourses of the "lazy" African (the Lamba in Zambia). Section 2 analyzes a study carried out in rural Zambia to illustrate the relationship between stereotypes held by many Europeans, particular aspects of the colonial project, and the social relations brought about by colonialism. Section 3 examines the ways in which present work and labor approaches in sub-Saharan Africa embody value judgements which leads to distorted documentation of the division of labor between opposite genders. Sections 4 through 7 look at a time-use study conducted in Zambia and argue that studies of such nature create value judgement on what comprises work, and about how researchers and planners classify this. Overall, this article has demonstrated that time-use surveys may provide inadequate understanding of women and men's work in the absence of an understanding of the local context in which the work is undertaken, and of labor markets. 相似文献
999.
Abbott MW Volberg RA 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》1999,15(3):233-242
While two-stage designs in problem gambling research are expensive and relatively difficult to execute, they have the potential to yield more accurate prevalence estimates as well as valuable additional information about gambling and problem gambling in the community. However, gains in precision are heavily dependent on the accuracy of the screening methods used and the sample sizes involved. Sound practice requires reliable information about the variances and confidence levels associated with different screens. In the spirit of contributing to the ongoing dialog about ways to improve the measurement of problem gambling, we examine several reasons to question whether the revised estimates offered by Gambino are in fact an improvement. 相似文献
1000.
A methodological strategy for a one-number census in the UK 总被引:1,自引:1,他引:0
Brown JJ Diamond ID Chambers RL Buckner LJ Teague AD 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》1999,162(2):247-267
As a result of lessons learnt from the 1991 census, a research programme was set up to seek improvements in census methodology. Underenumeration has been placed top of the agenda in this programme, and every effort is being made to achieve as high a coverage as possible in the 2001 census. In recognition, however, that 100% coverage will never be achieved, the one-number census (ONC) project was established to measure the degree of underenumeration in the 2001 census and, if possible, to adjust fully the outputs from the census for that undercount. A key component of this adjustment process is a census coverage survey (CCS). This paper presents an overview of the ONC project, focusing on the design and analysis methodology for the CCS. It also presents results that allow the reader to evaluate the robustness of this methodology. 相似文献