全文获取类型
收费全文 | 528篇 |
免费 | 54篇 |
国内免费 | 2篇 |
专业分类
林业 | 43篇 |
农学 | 25篇 |
基础科学 | 2篇 |
87篇 | |
综合类 | 56篇 |
农作物 | 34篇 |
水产渔业 | 35篇 |
畜牧兽医 | 221篇 |
园艺 | 19篇 |
植物保护 | 62篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 16篇 |
2017年 | 11篇 |
2016年 | 16篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 42篇 |
2012年 | 24篇 |
2011年 | 29篇 |
2010年 | 19篇 |
2009年 | 19篇 |
2008年 | 24篇 |
2007年 | 27篇 |
2006年 | 30篇 |
2005年 | 29篇 |
2004年 | 24篇 |
2003年 | 27篇 |
2002年 | 26篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1981年 | 6篇 |
1977年 | 3篇 |
1974年 | 3篇 |
1973年 | 9篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1967年 | 3篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1962年 | 3篇 |
1955年 | 5篇 |
排序方式: 共有584条查询结果,搜索用时 15 毫秒
101.
Synthesis and evaluation of hydroxyazolopyrimidines as herbicides; the generation of amitrole in planta
下载免费PDF全文
![点击此处可从《Pest management science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
102.
103.
104.
Bruce K. Wobeser Dale L. Godson Daniel Rejmanek Patricia Dowling 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(8):851-853
A protozoal parasite identified as Neospora hughesi was found in inflammatory lesions in the central nervous system of a Canadian-born adult horse presented with neurological signs. This is believed to be the first case of equine protozoal myeloencephalitis (EPM) caused by Neospora hughesi in a horse outside of the United States. 相似文献
105.
Embryogenic cultures of loblolly pine (Pinus taeda L.), slash pine (Pinus elliottii Engelm.), longleaf pine (Pinus palustris Mill.) and slash pine x longleaf pine hybrids were initiated from immature seeds on an initiation medium containing 13.57 microM 2,4-dichlorophenoxyacetic acid and 2.22 microM benzylaminopurine. Embryogenic cultures proliferated and somatic embryos developed, matured and germinated following a modified protocol and media originally developed for radiata pine (Pinus radiata D. Don.) somatic seedling production. A discrete, light-sensitive pre-germination stage and a later germination (radicle emergence) stage were identified by the differential response of somatic embryos to light of different wavelengths. Different light quality treatments were applied during the pre-germination and germination steps, using cool white fluorescent bulbs or light-emitting diodes (LEDs), or both. In general, red wavelengths provided by LEDs during these steps resulted in higher frequencies of somatic embryo germination (up to 64%) and conversion (up to 50%), longer tap roots and more first-order lateral roots than the standard cool white fluorescent treatments or treatment with blue wavelengths from LEDs. In addition, exposure to red light allowed germination of somatic embryos of some clones that failed to produce germinants under fluorescent light. Germination and conversion were further enhanced by sequential application of cool white fluorescent light and red light, resulting in up to 100% germination and conversion in one experiment. Longleaf pine somatic embryos were especially responsive to the light quality treatments, resulting in the first report of somatic seedling production for this species. 相似文献
106.
107.
Francesc Montané Pere Casals Marc Taull Bernard Lambert Mark R. T. Dale 《Annals of Forest Science》2009,66(6):612-612
108.
Marina L. Leis M. Elyse Salpeter Bianca S. Bauer Dale L. Godson Bruce H. Grahn 《Veterinary ophthalmology》2017,20(4):365-371
A 15‐year‐old, neutered male, Shih Tzu cross developed progressive corneal stromal thickening and vascularization of the right eye, and 5 months later, of the left eye. Both eyes became blind due to extensive corneal opacification and were enucleated. Light microscopic examination revealed a diffuse corneal infiltrate of neoplastic mesenchymal cells, and immunohistochemistry revealed diffuse cytoplasmic vimentin immunoreactivity and variable cytoplasmic and nuclear immunoreactivity for S100 in the neoplastic cells. Transmission electron microscopy revealed desmosomes between contiguous cells, thread‐like cytoplasmic processes coated with basement membrane, extracellular bundles of collagen, and axonal degeneration consistent with features of a nerve sheath neoplasm. This is the first report of primary, bilateral corneal nerve sheath sarcoma in a canine. 相似文献
109.
Clayton S. MILLER Mark HEBBLEWHITE John M. GOODRICH Dale G. MIQUELLE 《Integrative zoology》2010,5(4):378-389
Over the past half century, wildlife research has relied on technological advances to gain additional insight into the secretive lives of animals. This revolution started in the 1960s with the development of radio telemetry and continues today with the use of Global Positioning System (GPS)-based research techniques. In the present paper we review the history of radio telemetry from its origins with grizzly bears in Yellowstone to its early applications in tiger research and conservation in Asia. We address the different types of data that are available using radio telemetry as opposed to using other research techniques, such as behavioral observations, camera trapping, DNA analysis and scat analysis. In the late 1990s, the rapid development of GPS collar technology revolutionized wildlife research. This new technology has enabled researchers to dramatically improve their ability to gather data on animal movements and ecology. Despite the ecological and conservation benefits of radio telemetry, there have been few telemetry studies of tigers in the wild, and most have been on the Bengal or Amur subspecies. We close with an assessment of the current tiger conservation efforts using GPS technology and discuss how this new information can help to preserve tigers for future generations. 相似文献
110.