全文获取类型
收费全文 | 291篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
系统科学 | 11篇 |
教育与普及 | 1篇 |
理论与方法论 | 1篇 |
现状及发展 | 19篇 |
研究方法 | 5篇 |
综合类 | 246篇 |
自然研究 | 11篇 |
出版年
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 11篇 |
2011年 | 22篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 18篇 |
2006年 | 42篇 |
2005年 | 43篇 |
2004年 | 63篇 |
2003年 | 32篇 |
2002年 | 13篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1979年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有294条查询结果,搜索用时 15 毫秒
151.
Thrasher AJ Gaspar HB Baum C Modlich U Schambach A Candotti F Otsu M Sorrentino B Scobie L Cameron E Blyth K Neil J Abina SH Cavazzana-Calvo M Fischer A 《Nature》2006,443(7109):E5-6; discussion E6-7
Gene therapy has been remarkably effective for the immunological reconstitution of patients with severe combined immune deficiency, but the occurrence of leukaemia in a few patients has stimulated debate about the safety of the procedure and the mechanisms of leukaemogenesis. Woods et al. forced high expression of the corrective therapeutic gene IL2RG, which encodes the gamma-chain of the interleukin-2 receptor, in a mouse model of the disease and found that tumours appeared in a proportion of cases. Here we show that transgenic IL2RG does not necessarily have potent intrinsic oncogenic properties, and argue that the interpretation of this observation with respect to human trials is overstated. 相似文献
152.
153.
154.
155.
156.
Jaime Jiménez Juan C. Escalante José Aguirre-Vázquez 《Systemic Practice and Action Research》1997,10(3):255-269
An adaptation of a First-World planning method was successfully used to help solve the problematic situation confronted by
a Third-World higher education institution. The Search Conference is a method which enables the necessary conditions for a
set of individuals to engage into a comprehensive process of reflection and design over a specific social system or domain.
While preserving its essential characteristics, the Search Conference has been adapted to respond to a Third-World organizational
environment. The realization of a “massive” conference in a Mexican public university triggered a participative strategic
planning process of long-lasting consequences. The university community designed a desired future for the institution which
became the guiding force to mobilize it in the agreed-upon direction. They also learned how to plan and carry on projects
participatively. Some tangible results are the identification of students' regional demand, with the consequent creation of
four new bachelors degrees and two masters degrees; the creation of a program to support those faculty members who would be
willing to undertake masters and doctoral studies in outside prestigious universities; the increase in enrollment as a result
of combined actions; and the opening of two extension centers off campus to improve the external community's involvement.
In conclusion, a change of attitude emerged from the conference, which has been instrumental for the continuing involvement
of the internal community in the creation of a new university agreeable to all. 相似文献
157.
158.
159.
在几十到一百多毫瓦的入射光功率条件下,发现高斯光束通过BSO晶体后的远场光斑中心处的光强随入射光功率具有明显的非线性效应,分析了引起这一现象的理论机制,实验研究表明理论与实验相符。 相似文献
160.