全文获取类型
收费全文 | 2587篇 |
免费 | 65篇 |
专业分类
管理学 | 420篇 |
民族学 | 20篇 |
人口学 | 309篇 |
丛书文集 | 28篇 |
理论方法论 | 207篇 |
综合类 | 164篇 |
社会学 | 1152篇 |
统计学 | 352篇 |
出版年
2023年 | 25篇 |
2022年 | 18篇 |
2021年 | 31篇 |
2020年 | 72篇 |
2019年 | 90篇 |
2018年 | 107篇 |
2017年 | 142篇 |
2016年 | 110篇 |
2015年 | 61篇 |
2014年 | 92篇 |
2013年 | 339篇 |
2012年 | 232篇 |
2011年 | 115篇 |
2010年 | 93篇 |
2009年 | 87篇 |
2008年 | 76篇 |
2007年 | 76篇 |
2006年 | 57篇 |
2005年 | 68篇 |
2004年 | 113篇 |
2003年 | 104篇 |
2002年 | 103篇 |
2001年 | 56篇 |
2000年 | 44篇 |
1999年 | 28篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1996年 | 21篇 |
1995年 | 12篇 |
1994年 | 20篇 |
1993年 | 12篇 |
1992年 | 18篇 |
1991年 | 14篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 17篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1983年 | 18篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1970年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有2652条查询结果,搜索用时 15 毫秒
1.
Fire and restoration of the largest urban forest of the world in Rio de Janeiro City,Brazil 总被引:1,自引:1,他引:0
National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest urban forest in the world. Its floristic composition is typical of Atlantic Rain Forest. The reserve is being altered because of fire occurrences and urban expansion. This study identified locations and causes of forest fires, and makes management recommendations to restore damaged areas. From 1991 to 2000, forest firefighters recorded an average of 75-fire occurrences/year. Identified causes included hot air balloons (24%), intentional (24%), rubbish burning (21%) and religious practices (17%). Primary fuels included invasive grasses and ferns. Although hot air balloons destroyed larger areas of forest in each occurrence, a greater number of fires started in the invasive vegetation along roads that bisect the forest. In response to recurrent forests, invasive vegetation has spread gradually into the forest increasing forest degradation. To decrease fire damage, sites with high fire frequencies and density of invasive vegetation were planted with less flammable species. Results indicate that fire frequency decreased and density of invasive vegetation declined. This approach appears to prevent fire incidence, reduce the need for fire fighting, and preserve existing biodiversity. 相似文献
2.
ChrisdeWet 《河海大学学报(哲学社会科学版)》2002,4(2):16-20
论文在讨论四个移民典型案例的基础上 ,讨论在项目中与政策相关的教训 相似文献
3.
Two habituation experiments were conducted to investigate how 4‐month‐old infants perceive partly occluded shapes. In the first experiment, we presented a simple, partly occluded shape to the infants until habituation was reached. Then we showed either a probable completion (one that would be predicted on the basis of both local and global cues) or an improbable completion. Longer looking times were found for the improbably completed shape (compared to probable and control conditions), suggesting that the probable shape was perceived during partial occlusion. In the second experiment, infants were habituated to more ambiguous partly occluded shapes, where local and global cues would result in different completions. For adults, the percept of these shapes is usually dominated by global influences. However, after habituation the infants looked longer at the globally completed shapes. These results suggest that by the age of 4 months, infants are able to infer the perceptual completion of partly occluded shapes, but for more ambiguous shapes, this completion seems to be dominated by local influences. 相似文献
4.
5.
ETHNIC PLACES, POSTMODERNISM, AND URBAN CHANGE IN HOUSTON 总被引:1,自引:0,他引:1
Jan Lin 《The Sociological quarterly》1995,36(4):629-647
City managers and urban sociologists traditionally viewed ethnic places as undesirable areas of overcrowding and social pathology. Regarded as either transitional districts or obstacles to modernization, ethnic places were subject to slum clearance during the modernist phase of urban development. Ethnic places have acquired a new historical and sentimental salience in the "postmodern" developmental era. Preservationist activists and minority "place entrepreneurs" project ethnic culture and symbolic representations in defensive or proactive ways to stimulate neighborhood revitalization. These trends are evident in the recent urban developmental history of Houston, Texas. 相似文献
6.
We re-evaluate Andreu and Spanos's findings in favour of trend stationarity by considering the extended Nelson-Plosser data set. This expanded (to 1988) data set includes a period of rather different behaviour compared with the original Nelson-Plosser data used by Andreou and Spanos. We find that Andreou and Spanos's models (with only minor adjustments) exhibit remarable stability over this extended period, and indicate that their conclusions are more robust than they have shown. 相似文献
7.
Jan C. H. van Eijkeren 《Risk analysis》2002,22(1):159-173
A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori. 相似文献
8.
The development of a Municipal Information System, or currently better known as a local spatial data infrastructure, is considered complex due to the required inter-institutional relationships. In many developing countries Geographical Information Systems (GISs) are introduced but the benefits are modest as no changes take place in technical and organisational structure of organisations. Digital databases and computer-aided design (CAD) maps are mushrooming in great variety within different private and public institutions, municipal organisations and even within single departments and with structures similar to the paper period and thus operating on a stand-alone basis.Many national mapping agencies are not able to provide large-scale digital urban base maps, while the absence or low quality of cadastres makes those basic core data sets unavailable or inaccessible. The result is that duplication and incompatible data are frequently observed and also donor-driven stand-alone projects have a limited impact through the lack of institutional embedding and are not able to mature from the project to the institutional level. However, a positive sign is that there is an increasing awareness among data producers and consumers that investments in the development of digital data sets should be combined to reduce costs and increase benefits from especially GIS, and information and communication technology (ICT) in general.Within Trujillo a long-term vision was developed to make full use of ICT and GIS to modernise all operations of the Municipality to increase the efficiency and effectiveness of its tasks. However, large investments are not feasible due to the very limited municipal budgets. To guarantee the support of the municipal council, short-term results are required. This paper describes three ‘products’ as part of the vision to develop through a step-by-step approach a local spatial data infrastructure for Trujillo.The three, rather different, products are:
- 1. fiscal cadastre, to increase municipal revenues through property taxation;
- 2. an ‘environmental atlas’ based on a compatible spatial and attribute data sets from a variety of organisations; and
- 3. a municipal website with interactive GIS and meta data information.
9.
Leontine van de Ven Marcel Post Luc de Witte Wim van den Heuvel 《Disability & Society》2005,20(3):311-329
The concept of integration is not well defined. It not known how people with disabilities experience integration. In this study qualitative methods were used. The aim of the article is to define a model of successful integration based on the perspectives of people with disabilities and people within their social environment. Integration consists of five elements: functioning ordinarily without receiving special attention, mixing with others that are not disabled, taking part in society, trying to realize one’s potential and directing one’s own life. Integration is obtained through a process of interaction between a person with a disability and society. This process is influenced by personal, societal and support factors. The individual with a disability and society have a mutual responsibility with respect to integration. 相似文献
10.
惠保德 《郑州轻工业学院学报(社会科学版)》2002,3(2):72-74
价值观的形成有其自身的规律 ,并受到社会因素和个体内在因素的影响。当代青年正处在我国改革开放进一步深化和社会主义市场经济体制逐步确立及自我意识发展和自我需要扩大的时期 ,因此 ,他们的价值观必然打着当今时代的烙印 ,具有开放性、先锋化、情绪性等特点 ,他们追求高效、公正、互利 ,追求求职与成才相结合 ,但同时 ,其自身的身心失范问题也日趋严重。 相似文献