全文获取类型
收费全文 | 615篇 |
免费 | 15篇 |
国内免费 | 54篇 |
专业分类
684篇 |
出版年
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 4篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 32篇 |
2011年 | 29篇 |
2010年 | 31篇 |
2009年 | 38篇 |
2008年 | 31篇 |
2007年 | 19篇 |
2006年 | 22篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 18篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1989年 | 6篇 |
1988年 | 12篇 |
1985年 | 9篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1972年 | 4篇 |
1968年 | 3篇 |
1959年 | 9篇 |
1958年 | 16篇 |
1957年 | 13篇 |
1956年 | 27篇 |
1955年 | 14篇 |
1954年 | 10篇 |
1953年 | 21篇 |
1952年 | 14篇 |
1951年 | 15篇 |
1950年 | 14篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
111.
112.
多效唑(MET)对啤酒花试管苗生长和移栽的影响 总被引:5,自引:0,他引:5
在培养基中加入0.1-0.2mg/L浓度的多效唑(MET),啤酒花试管苗植株矮壮,单株生根数量增加、移栽成活率提高13%。0.5-2.0mg/L时,试管苗基部愈伤组织增多,枝叶失绿,生长受到抑制。初步发现多将唑对啤酒花试管苗的效力与葡萄糖用量呈正相关。 相似文献
113.
114.
115.
116.
A. R. Overman 《Plant and Soil》1975,43(1-3):663-670
117.
Abstract The type-species of four genera of Pseudococcidae are studied. Fonscolombia Lichtenstein is redefined, the type-species, Fonscolombia graminis Lichtenstein is assigned to the Pseudococcidae, redescribed and a lectotype designated. Laboulbenia Lichtenstein is accepted as an objective synonym of Antonina Signoret. Tetrura Lichtenstein ( non : Lesson) is accepted as an objective synonym of Coccura Sulc. The adult female of the material of this species which Lichtenstein misidentified as Tetrura rubi (Schrank) is redescribed and illustrated. Brevennia Goux is redefined, and the type-species Ripersia (Brevennia) tetrapora Goux redescribed. The characteristics of Asphodelococcus Morrison are discussed, the type-species Ripersia asphodeli Bodenheimer redescribed and a neotype designated; A.meoconcitae Tranfaglia & Marotta is a new synonym of A. asphodeli . 相似文献
118.
119.
The use of the computer metaphor has led to the proposal of mind architecture (Pylyshyn 1984; Newell 1990) as a model of the organization of the mind. The dualist computational model, however, has, since the earliest days of psychological functionalism, required that the concepts mind architecture and brain architecture be remote from each other. The development of both connectionism and neurocomputational science, has sought to dispense with this dualism and provide general models of consciousness – a uniform cognitive architecture –, which is in general reductionist, but which retains the computer metaphor. This paper examines, in the first place, the concepts of mind architecture and brain architecture, in order to evaluate the syntheses which have recently been offered. It then moves on to show how modifications which have been made to classical functionalist mind architectures, with the aim of making them compatible with brain architectures, are unable to resolve some of the most serious problems of functionalism. Some suggestions are given as to why it is not possible to relate mind structures and brain structures by using neurocomputational approaches, and finally the question is raised of the validity of reductionism in a theory which sets out to unite mind and brain architectures. 相似文献
120.