全文获取类型
收费全文 | 9427篇 |
免费 | 802篇 |
国内免费 | 2篇 |
出版年
2022年 | 33篇 |
2021年 | 74篇 |
2020年 | 55篇 |
2019年 | 66篇 |
2018年 | 146篇 |
2017年 | 186篇 |
2016年 | 273篇 |
2015年 | 410篇 |
2014年 | 435篇 |
2013年 | 549篇 |
2012年 | 735篇 |
2011年 | 737篇 |
2010年 | 436篇 |
2009年 | 381篇 |
2008年 | 556篇 |
2007年 | 561篇 |
2006年 | 523篇 |
2005年 | 535篇 |
2004年 | 461篇 |
2003年 | 418篇 |
2002年 | 397篇 |
2001年 | 166篇 |
2000年 | 175篇 |
1999年 | 147篇 |
1998年 | 62篇 |
1997年 | 53篇 |
1996年 | 49篇 |
1995年 | 45篇 |
1994年 | 37篇 |
1993年 | 36篇 |
1992年 | 73篇 |
1991年 | 77篇 |
1990年 | 49篇 |
1989年 | 81篇 |
1988年 | 67篇 |
1987年 | 59篇 |
1986年 | 53篇 |
1985年 | 57篇 |
1984年 | 49篇 |
1983年 | 56篇 |
1982年 | 45篇 |
1981年 | 44篇 |
1979年 | 41篇 |
1978年 | 34篇 |
1976年 | 45篇 |
1975年 | 41篇 |
1974年 | 56篇 |
1973年 | 41篇 |
1972年 | 34篇 |
1971年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
16.
HAROLD St. JOHN F.L.S. 《Biological journal of the Linnean Society. Linnean Society of London》1972,4(4):305-310
Sydney Parkinson, aged 18, was Sir Joseph Banks' private assistant and artist on Captain Cook's first voyage around the world. Parkinson died on the voyage. Among his effects delivered to his brother Stanfield were drawings and notes which the latter published as a journal. Included in it is a chapter on the economic plants of Tahiti, and most of them are given scientific names, some of which were new. In 1941 Fosberg adopted two of them to form names which were new combinations under Artocarpus , and Inocarpus . The writer now indicates that Parkinson's names of 1773 were mononomials, hence invalid, but that in the German edition of 1774, edited by Herr "Z", the names are valid binomials. For the two plants mentioned, the authorship of the combinations is revised. 相似文献
17.
18.
19.
Dan Cog?lniceanu Laurentiu Rozylowicz Paul Székely Ciprian Samoil? Florina St?nescu Marian Tudor Diana Székely Ruben Iosif 《ZooKeys》2013,(341):49-76
The reptile fauna of Romania comprises 23 species, out of which 12 species reach here the limit of their geographic range. We compiled and updated a national database of the reptile species occurrences from a variety of sources including our own field surveys, personal communication from specialists, museum collections and the scientific literature. The occurrence records were georeferenced and stored in a geodatabase for additional analysis of their spatial patterns. The spatial analysis revealed a biased sampling effort concentrated in various protected areas, and deficient in the vast agricultural areas of the southern part of Romania. The patterns of species richness showed a higher number of species in the warmer and drier regions, and a relatively low number of species in the rest of the country. Our database provides a starting point for further analyses, and represents a reliable tool for drafting conservation plans. 相似文献
20.