全文获取类型
收费全文 | 1608篇 |
免费 | 99篇 |
专业分类
1707篇 |
出版年
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 15篇 |
2017年 | 15篇 |
2016年 | 28篇 |
2015年 | 36篇 |
2014年 | 45篇 |
2013年 | 138篇 |
2012年 | 78篇 |
2011年 | 87篇 |
2010年 | 57篇 |
2009年 | 54篇 |
2008年 | 103篇 |
2007年 | 102篇 |
2006年 | 83篇 |
2005年 | 107篇 |
2004年 | 118篇 |
2003年 | 99篇 |
2002年 | 99篇 |
2001年 | 16篇 |
2000年 | 14篇 |
1999年 | 16篇 |
1998年 | 29篇 |
1997年 | 16篇 |
1996年 | 26篇 |
1995年 | 15篇 |
1994年 | 26篇 |
1993年 | 17篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 8篇 |
1988年 | 16篇 |
1987年 | 18篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1972年 | 5篇 |
排序方式: 共有1707条查询结果,搜索用时 15 毫秒
31.
Analysis of Petal Anthocyanins to Investigate Flower Coloration of Zhongyuan (Chinese) and Daikon Island (Japanese) Tree Peony Cultivars 总被引:14,自引:0,他引:14
Liang-Sheng Wang Aya Shiraishi Fumio Hashimoto Noriaki Aoki Keiichi Shimizu Yusuke Sakata 《Journal of plant research》2001,114(1):33-43
Pn, Pg; Pn, Pg > Cy ; Pn, Cy and Pn, Cy > Pg groups. Each group consequently specified significant features among CIELAB color notation and petal pigmentation, being
adequate to characterize tree peony flowers as similar between Zhongyuan and Daikon Island cultivars, thus the cultivars of
the two areas are suggested to be related to one another.
Received 25 April 2000/ Accepted in revised form 21 December 2000 相似文献
32.
33.
Osamu Yamada Shuichi Ishida Fumio Futatsuya Kensaku Ito Hiroshi Yamamoto Katsura Munakata 《Bioscience, biotechnology, and biochemistry》2013,77(6):1235-1240
The discovery that anisomycin showed plant growth-regulating activity led to the investigation of compounds having p-methoxyphenyl group; the p-anisole derivatives. 4-Methoxydiphenylmethanes and related compounds inhibited the growth of both shoots and roots in test plants. Growth-inhibitory activity in the series of 4-methoxydiphenylmethanes was lowered by an increase in the electron donating or withdrawing ability of the substituent and was parabolically dependent on the Hammett’s σ. Selective actions of these compounds in their growth inhibition are discussed based on correlations between their activities against barnyard grass and other test plants.Some 4-methoxydiphenylmethanes induced chlorosis, a disturbance in phototropism or geotropism, and root hypertrophy. 相似文献
34.
35.
Fumio Sawada Yasuhiko Miyauchi Hiroshi Tanaka Shinji Matsumoto 《Biochemical and biophysical research communications》1982,104(2):657-663
A novel method for the preparation of intact chromatin from the slime mold which retains the property of RNA synthesis is described. Preparations from G2-cells were highly active, while those from metaphase-cells were inactive. The plasmodial cells were disrupted by gentle homogenization on a polyethylene sieve in a neutral isotonic sucrose medium containing Mg++, deoxycholate and EGTA, a Ca++-chelating agent. The nuclei were lysed in a hypotonic buffer without use of EDTA and chromatin was precipitated by centrifugation after addition of Mg++. 相似文献
36.
37.
The allelopathic effects of the two sesquiterpene lactones, costunolide and parthenolide, isolated from the leaves of Magnolia grandiflora L. were evaluated on the wheat (Triticum aestivum L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus L.) and onion (Allium cepa L.). Seed germination of the test species was significantly reduced at 500 μg/ml by both compounds. Both sesquiterpenes showed pronounced inhibition of root length of the test species and the inhibitory effect was concentration-dependent. In addition, shoot growth of the four species was significantly inhibited at all the concentrations tested (10–500 μg/ml). Parthenolide reduced germination and inhibited seedling growth more than costunolide. Inhibition of root growth was generally greater than that of shoot growth. The results encourage the use of these sesquiterpenes as models for development of new herbicides. 相似文献
38.
39.
40.
Yoshikawa F Banno Y Otani Y Yamaguchi Y Nagakura-Takagi Y Morita N Sato Y Saruta C Nishibe H Sadakata T Shinoda Y Hayashi K Mishima Y Baba H Furuichi T 《PloS one》2010,5(11):e13932