全文获取类型
收费全文 | 7203篇 |
免费 | 703篇 |
国内免费 | 384篇 |
专业分类
林业 | 717篇 |
农学 | 941篇 |
基础科学 | 317篇 |
1186篇 | |
综合类 | 1405篇 |
农作物 | 364篇 |
水产渔业 | 566篇 |
畜牧兽医 | 1946篇 |
园艺 | 198篇 |
植物保护 | 650篇 |
出版年
2023年 | 81篇 |
2022年 | 110篇 |
2021年 | 171篇 |
2020年 | 192篇 |
2019年 | 234篇 |
2018年 | 280篇 |
2017年 | 280篇 |
2016年 | 264篇 |
2015年 | 312篇 |
2014年 | 307篇 |
2013年 | 388篇 |
2012年 | 440篇 |
2011年 | 469篇 |
2010年 | 425篇 |
2009年 | 381篇 |
2008年 | 406篇 |
2007年 | 366篇 |
2006年 | 375篇 |
2005年 | 350篇 |
2004年 | 216篇 |
2003年 | 179篇 |
2002年 | 118篇 |
2001年 | 209篇 |
2000年 | 217篇 |
1999年 | 202篇 |
1998年 | 126篇 |
1997年 | 152篇 |
1996年 | 122篇 |
1995年 | 113篇 |
1994年 | 73篇 |
1993年 | 88篇 |
1992年 | 92篇 |
1991年 | 84篇 |
1990年 | 89篇 |
1989年 | 61篇 |
1988年 | 59篇 |
1987年 | 31篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1976年 | 5篇 |
1971年 | 7篇 |
1966年 | 7篇 |
1963年 | 5篇 |
1892年 | 7篇 |
排序方式: 共有8290条查询结果,搜索用时 25 毫秒
1.
校院两级管理是高等院校内部管理体制改革创新的必然趋势,对高等院校盘活存量、激活增量具有重要作用。文章系统梳理了国内外高等院校内部管理体制改革和校院两级管理模式以及教科研指标体系的差异和特征,着重聚焦当前地方农业高校教科研指标体系构建中存在的问题,探析地方农业高校校院两级管理教科研指标体系构建的关键因素和环节,提出了“核心+特色”校院两级指标设置和“个人+团队”教师考核评价方式的两项对策,以期为地方农业高校校院两级管理教科研指标考核和评价提供借鉴和参考。 相似文献
2.
为了促进食品安全和养猪业的健康发展,禁止在饲料中使用促生长抗生素势在必行。随着我国的饲料禁抗相关法规的推行,饲料企业被严格禁止在饲料生产过程中加入抗生素,这也导致了猪场疾病尤其是肠道疾病的高发,而仔猪肠道发育未完全,免疫系统未发育成熟,更容易发生严重的腹泻甚至死亡。文章对几种常见的仔猪细菌性腹泻疾病进行了回顾,病原包括大肠杆菌、沙门氏菌、魏氏梭菌,讨论了它们的临床症状与防控措施,为猪场在防控这些细菌性腹泻提供参考。 相似文献
3.
4.
D R Clements M D Day V Oeggerli S C Shen L A Weston G F Xu F D Zhang X Zhu 《Weed Research》2019,59(3):155-169
Increasingly, weeds have been taking on global distributions. With the proliferation of invasive weeds has come the challenge of managing these species over broad geographical regions, with diverse habitats and political jurisdictions. Here, we review the management of Mikania micrantha Kunth (Asteraceae; mile‐a‐minute) throughout its invaded range, extending through most of the Pacific islands and southern and south‐east Asia. Context matters when determining the best course of action for managing M. micrantha, as it has invaded a large variety of agricultural and natural systems. In Queensland, Australia and Florida, USA, M. micrantha has been targeted in relatively successful eradication campaigns, highlighting the importance of early detection and rapid response methods, while elsewhere in its invaded range, populations are either still increasing or showing limited signs of decline. An inter‐regional approach to research and management should incorporate successful management strategies employed throughout the invaded range including, but not limited to, chemical and cultural control practices, manual and mechanical control, classical biological control using the rust fungus Puccinia spegazzinii, plant–plant competition and integrated approaches utilising two or more control methods concurrently. Additional knowledge of M. micrantha genetics is required to determine if management approaches could be fine‐tuned for particular populations. Countries bordering the Mekong River formed a network in 2011 to co‐ordinate the management of invasive species such as M. micrantha. Expanding such a collaborative approach to other regions could further reduce populations of M. micrantha and limit its spread. 相似文献
5.
从甜瓜根际酸性土壤中分离筛选到1株耐铝甜瓜枯萎病拮抗菌,命名为A2。根据表型、生理生化特征和16S rRNA基因序列相似性分析,将其鉴定为Pseudomonas sp.。菌株A2对甜瓜枯萎病病原菌的相对防效为68.3%,且拮抗能力具有遗传稳定性。相比AlCl3处理,菌株A2对Al2(SO4)3表现出了更好的耐受性,最高可耐受50mmol/L Al3+。在含有A13+的S-LB培养基中,菌株最适生长温度为30 ℃;培养基初始pH值的降低会加剧A13+对菌株A2的毒害作用。研究结果可为含活性铝的酸性土壤中甜瓜枯萎病的生物防治提供优良菌株资源和理论基础。 相似文献
6.
7.
X. Y. Wang C. W. Zhang W. T. Huang J. Yue J. J. Dou L. Y. Wang Q. Wang Y. Q. Cheng 《Plant pathology》2020,69(1):149-158
Efforts to control viral diseases of grapevine include the production of certified material and development of virus-resistant transgenic grapevines. However, effective antiviral agents, once the viruses have infected the plants, are still lacking. This study shows that a crude garlic extract has significant antiviral activity against grapevine viruses. Replication of grapevine leafroll-associated virus 2 (GLRaV-2) was obviously inhibited in grapevine cv. Cabernet Sauvignon calli treated with diluted (1:100) garlic extract. The relative RNA levels of GLRaV-2 and grapevine fleck virus (GFkV) in cv. Summer Black grapevine in in vitro-grown plantlets 10 days after treatment with diluted (1:100) garlic extract were about 22% and 20%, respectively, of that in controls. The viral RNA accumulation of GLRaV-2, GFkV, grapevine virus A (GVA), grapevine fanleaf virus (GFLV) and grapevine rupestris stem pitting-associated virus (GRSPaV) in field-grown grapevine cv. Centennial Seedless plants sprayed with diluted (1:100) garlic extract were about 31–40%, 26–38%, 18–31%, 17–42% and 15–18%, respectively, of that in controls. Moreover, the garlic extract treatment led to a significant decrease in viral RNA accumulation of GLRaV-3, GLRaV-2, GVA, GFkV, GFLV, GRSPaV and grapevine Pinot Gris virus in pot-grown grapevine cv. Shine Muscat plants, and viral disease symptoms in these plants were obviously attenuated. In addition, this extract significantly induced expression of pathogenesis-related protein genes and stimulated activity of antioxidant enzymes in grapevines. Taken together, these results indicate that the crude garlic extract acts as a significant inhibitor against a broad range of grapevine viruses. 相似文献
8.
9.
Seyedeh Masoumeh Fotoukkiaii Zoë Tan Wenxin Xue Nicky Wybouw Thomas Van Leeuwen 《Pest management science》2020,76(3):1154-1163
10.