全文获取类型
收费全文 | 9816篇 |
免费 | 133篇 |
国内免费 | 17篇 |
专业分类
教育 | 6835篇 |
科学研究 | 939篇 |
各国文化 | 137篇 |
体育 | 744篇 |
综合类 | 9篇 |
文化理论 | 113篇 |
信息传播 | 1189篇 |
出版年
2021年 | 71篇 |
2020年 | 114篇 |
2019年 | 190篇 |
2018年 | 283篇 |
2017年 | 349篇 |
2016年 | 340篇 |
2015年 | 217篇 |
2014年 | 268篇 |
2013年 | 2251篇 |
2012年 | 233篇 |
2011年 | 280篇 |
2010年 | 230篇 |
2009年 | 217篇 |
2008年 | 229篇 |
2007年 | 228篇 |
2006年 | 161篇 |
2005年 | 192篇 |
2004年 | 183篇 |
2003年 | 154篇 |
2002年 | 161篇 |
2001年 | 169篇 |
2000年 | 152篇 |
1999年 | 150篇 |
1998年 | 113篇 |
1997年 | 112篇 |
1996年 | 115篇 |
1995年 | 91篇 |
1994年 | 97篇 |
1993年 | 86篇 |
1992年 | 106篇 |
1991年 | 127篇 |
1990年 | 94篇 |
1989年 | 102篇 |
1988年 | 89篇 |
1987年 | 103篇 |
1986年 | 92篇 |
1985年 | 117篇 |
1984年 | 105篇 |
1983年 | 90篇 |
1982年 | 93篇 |
1981年 | 84篇 |
1980年 | 59篇 |
1979年 | 94篇 |
1978年 | 103篇 |
1977年 | 77篇 |
1976年 | 59篇 |
1975年 | 64篇 |
1974年 | 57篇 |
1972年 | 48篇 |
1971年 | 49篇 |
排序方式: 共有9966条查询结果,搜索用时 93 毫秒
1.
2.
3.
ABSTRACTThe preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity. 相似文献
4.
5.
James D. T. Tannock 《Higher Education Quarterly》1992,46(1):108-123
This article describes the Engineering Professors' Conference (EPC) approach to quality assurance for Higher Education Institutions, which is currently the only formalized alternative to British Standard 5750 'Quality Systems'. The EPC approach is based on principles of quality assurance and Total Quality Management which have been developed in industry. These ideas are briefly outlined, and an opinion expressed on the interpretation and application of BSS7S0 for HE. The EPC model is explained, illustrated with example elements taken from the EPC Specification and Guidelines for Quality Assurance in Higher Education. A top-down approach to the development of an institutional quality system is described, based on a quality policy statement. Areas of activity which have an important impact on the quality of education are identified, emphasising the quality assurance requirements of academic departments. Supporting and administrative quality system requirements are also described, as these also play an important role in the quality of education. Formal quality procedures and documentation in key areas are proposed. 相似文献
6.
As a group, students with learning disabilities (LD) have social difficulties. One possible explanation for these difficulties is the unique way they process social information. Although students with LD may differ from their nondisabled peers in their social cognition, investigators have suggested the presence of subgroups within the population of students with LD who may differ in their social competence and, thereby, shed light on the source of the difficulties. The present exploratory study examined how two subgroups of students with LD in inclusive settings, students with high and low social status, perceive social situations. Using a sociometric technique, three students with LD receiving high social‐status ratings and three students with LD receiving low social‐status ratings were identified. A qualitative approach was used to gather and evaluate data from the participants and their teachers. Results suggested differences between the two subgroups in their (1) sensitivity to cues in the environment, (2) interpretation of social situations in relation to their own experiences, and (3) levels of self‐control. Implications of these findings for practice and future research are discussed. 相似文献
7.
8.
9.
10.