全文获取类型
收费全文 | 116篇 |
免费 | 0篇 |
专业分类
系统科学 | 1篇 |
丛书文集 | 1篇 |
现状及发展 | 25篇 |
研究方法 | 19篇 |
综合类 | 63篇 |
自然研究 | 7篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2015年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 12篇 |
2010年 | 1篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1996年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 5篇 |
1967年 | 2篇 |
1965年 | 5篇 |
1947年 | 1篇 |
排序方式: 共有116条查询结果,搜索用时 500 毫秒
81.
Kevin C. Elliott 《Studies in history and philosophy of science》2012,43(2):376-382
A number of scholars have recently drawn attention to the importance of iteration in scientific research. This paper builds on these previous discussions by drawing a distinction between epistemic and methodological forms of iteration and by clarifying the relationships between them. As defined here, epistemic iteration involves progressive alterations to scientific knowledge claims, whereas methodological iteration refers to an interplay between different modes of research practice. While distinct, these two forms of iteration are related in important ways. Contemporary research on the biological effects of nanomaterials illustrates that methodological iteration can help to “initiate,” “equip,” and “stimulate” epistemic iteration. 相似文献
82.
Familial dementia caused by polymerization of mutant neuroserpin. 总被引:13,自引:0,他引:13
R L Davis A E Shrimpton P D Holohan C Bradshaw D Feiglin G H Collins P Sonderegger J Kinter L M Becker F Lacbawan D Krasnewich M Muenke D A Lawrence M S Yerby C M Shaw B Gooptu P R Elliott J T Finch R W Carrell D A Lomas 《Nature》1999,401(6751):376-379
Aberrant protein processing with tissue deposition is associated with many common neurodegenerative disorders; however, the complex interplay of genetic and environmental factors has made it difficult to decipher the sequence of events linking protein aggregation with clinical disease. Substantial progress has been made toward understanding the pathophysiology of prototypical conformational diseases and protein polymerization in the superfamily of serine proteinase inhibitors (serpins). Here we describe a new disease, familial encephalopathy with neuroserpin inclusion bodies, characterized clinically as an autosomal dominantly inherited dementia, histologically by unique neuronal inclusion bodies and biochemically by polymers of the neuron-specific serpin, neuroserpin. We report the cosegregation of point mutations in the neuroserpin gene (PI12) with the disease in two families. The significance of one mutation, S49P, is evident from its homology to a previously described serpin mutations, whereas that of the other, S52R, is predicted by modelling of the serpin template. Our findings provide a molecular mechanism for a familial dementia and imply that inhibitors of protein polymerization may be effective therapies for this disorder and perhaps for other more common neurodegenerative diseases. 相似文献
83.
Changing the L:D intensity ratio of a synchronizing dark regime leads to characteristic modulations of the activity pattern of Chiroptera species. These modulations fit the predictions of WEVER'S oscillator model. 相似文献
84.
X-ray diffraction from living striated muscle during contraction 总被引:13,自引:0,他引:13
85.
Andrés E Askebjer P Bai X Barouch G Barwick SW Bay RC Becker KH Bergström L Bertrand D Bierenbaum D Biron A Booth J Botner O Bouchta A Boyce MM Carius S Chen A Chirkin D Conrad J Cooley J Costa CG Cowen DF Dailing J Dalberg E DeYoung T Desiati P Dewulf JP Doksus P Edsjö J Ekström P Erlandsson B Feser T Gaug M Goldschmidt A Goobar A Gray L Haase H Hallgren A Halzen F Hanson K Hardtke R He YD Hellwig M Heukenkamp H Hill GC Hulth PO Hundertmark S Jacobsen J Kandhadai V Karle A Kim J Koci B Köpke L 《Nature》2001,410(6827):441-443
Neutrinos are elementary particles that carry no electric charge and have little mass. As they interact only weakly with other particles, they can penetrate enormous amounts of matter, and therefore have the potential to directly convey astrophysical information from the edge of the Universe and from deep inside the most cataclysmic high-energy regions. The neutrino's great penetrating power, however, also makes this particle difficult to detect. Underground detectors have observed low-energy neutrinos from the Sun and a nearby supernova, as well as neutrinos generated in the Earth's atmosphere. But the very low fluxes of high-energy neutrinos from cosmic sources can be observed only by much larger, expandable detectors in, for example, deep water or ice. Here we report the detection of upwardly propagating atmospheric neutrinos by the ice-based Antarctic muon and neutrino detector array (AMANDA). These results establish a technology with which to build a kilometre-scale neutrino observatory necessary for astrophysical observations. 相似文献
86.
Preliminary observations on tickling oneself 总被引:5,自引:0,他引:5
87.
88.
E Spanopoulou A Early J Elliott N Crispe H Ladyman M Ritter S Watt F Grosveld D Kioussis 《Nature》1989,342(6246):185-189
89.
90.
Elliott JI 《Cellular and molecular life sciences : CMLS》1999,56(1-2):143-154
The assumption that T cells can only express a single receptor for antigen has in recent years been shown to be incorrect. However, the finding that a substantial number of T cells express two distinct antigen receptors at the cell surface raises a number of questions. In particular, it has been suggested that cells expressing low levels of a self-reactive T cell receptor may escape self-tolerance mechanisms and in certain situations trigger the onset of autoimmune disease. Such a hypothesis in turn raises questions central to the understanding of the nature of T cell recognition and the process of thymocyte maturation. 相似文献