全文获取类型
收费全文 | 540篇 |
免费 | 90篇 |
出版年
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 29篇 |
2011年 | 14篇 |
2010年 | 26篇 |
2009年 | 16篇 |
2008年 | 22篇 |
2007年 | 35篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 15篇 |
2003年 | 18篇 |
2002年 | 12篇 |
2001年 | 14篇 |
2000年 | 20篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 11篇 |
1969年 | 10篇 |
1968年 | 9篇 |
1966年 | 6篇 |
排序方式: 共有630条查询结果,搜索用时 109 毫秒
71.
72.
73.
74.
75.
76.
77.
Influence of assimilate demand on photosynthesis, diffusive resistances, translocation, and carbohydrate levels of soybean leaves 总被引:39,自引:29,他引:10
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rates of net photosynthesis and translocation, CO2 diffusive resistances, levels of carbohydrates, total protein, chlorophyll, and inorganic phosphate, and ribulose 1,5-diphosphate carboxylase activity were measured in soybean (Glycine max L. Merrill) leaves to ascertain the effect of altered assimilate demand. To increase assimilate demand, the pods, stems, and all but one leaf (the “source leaf”) of potted plants were completely shaded for 6 or 8 days and the responses of the illuminated source leaf were monitored. Rate of net photosynthesis in the source leaf of the shaded plants was found to increase curvilinearly to a maximum on the 8th day. The source leaf of the control plants (no sink shading) maintained a constant photosynthetic rate during this period. Vapor-phase resistance to CO2 diffusion did not vary with treatment, but mesophyll (liquid phase) resistance was significantly lower in the source leaf of the shaded plants. 相似文献
78.
Chemical analysis of the outer membrane and other layers of the cell envelope of Acinetobacter sp 总被引:10,自引:10,他引:0
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chemical analysis of fractions of the cell envelope of Acinetobacter sp. strain MJT/F5/199A, prepared by breakage in the French press and removal of plasma membranes, followed by sequential treatment with lysozyme and with papain, confirmed the existence of layers previously identified by electron microscopy. Outside the plasma membrane and periplasmic space, the envelope is composed of (i) a peptidoglycan-containing dense layer, (ii) an intermediate layer, (iii) a lipopolysaccharide-containing outer membrane, and (iv) an ordered array of protein subunits. A small amount of carbohydrate (3%) is found associated with protein in the fraction containing both the surface subunits and the intermediate layer. The papain-treated outer membranes contain 67% protein, 24% lipid, together with 11% lipopolysaccharide, and about 6% of non-lipopolysaccharide hexosamine. Lipid is located only in the papain-treated outer-membrane and is mainly phospholipid: 29% phosphatidyl glycerol, 30% phosphatidyl ethanolamine, and 40% cardiolipin. The principal fatty acid is C(18:1). Significant amounts of alcohols(16:1) and alcohols(18:1), which are found in Acinetobacter waxes, were recovered from the outer membrane. 相似文献
79.
80.