全文获取类型
收费全文 | 365篇 |
免费 | 22篇 |
国内免费 | 2篇 |
专业分类
林业 | 16篇 |
农学 | 39篇 |
基础科学 | 2篇 |
58篇 | |
综合类 | 65篇 |
农作物 | 9篇 |
水产渔业 | 14篇 |
畜牧兽医 | 157篇 |
园艺 | 10篇 |
植物保护 | 19篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 11篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 13篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 31篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 15篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 33篇 |
2005年 | 22篇 |
2004年 | 19篇 |
2003年 | 19篇 |
2002年 | 21篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有389条查询结果,搜索用时 15 毫秒
111.
Subedi R Shneor R Monaghan P Anderson BD Aniol K Annand J Arrington J Benaoum H Benmokhtar F Boeglin W Chen JP Choi S Cisbani E Craver B Frullani S Garibaldi F Gilad S Gilman R Glamazdin O Hansen JO Higinbotham DW Holmstrom T Ibrahim H Igarashi R de Jager CW Jans E Jiang X Kaufman LJ Kelleher A Kolarkar A Kumbartzki G Lerose JJ Lindgren R Liyanage N Margaziotis DJ Markowitz P Marrone S Mazouz M Meekins D Michaels R Moffit B Perdrisat CF Piasetzky E Potokar M Punjabi V Qiang Y Reinhold J Ron G 《Science (New York, N.Y.)》2008,320(5882):1476-1478
The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars. 相似文献
112.
Boyce M Bryant KF Jousse C Long K Harding HP Scheuner D Kaufman RJ Ma D Coen DM Ron D Yuan J 《Science (New York, N.Y.)》2005,307(5711):935-939
Most protein phosphatases have little intrinsic substrate specificity, making selective pharmacological inhibition of specific dephosphorylation reactions a challenging problem. In a screen for small molecules that protect cells from endoplasmic reticulum (ER) stress, we identified salubrinal, a selective inhibitor of cellular complexes that dephosphorylate eukaryotic translation initiation factor 2 subunit alpha (eIF2alpha). Salubrinal also blocks eIF2alpha dephosphorylation mediated by a herpes simplex virus protein and inhibits viral replication. These results suggest that selective chemical inhibitors of eIF2alpha dephosphorylation may be useful in diseases involving ER stress or viral infection. More broadly, salubrinal demonstrates the feasibility of selective pharmacological targeting of cellular dephosphorylation events. 相似文献
113.
114.
115.
甘蔗的虫害防治应该有一套特定的综合防治技术(1PM),毕竟一部分害虫的为害程度还是可以承受的.在综合防治中根据害虫对不同物种的偏好,可采取使用生物控制剂、杀虫剂及改进栽培技术等方法.一套有效的综合防治技术(1PM)有利于保护环境,并为种植者节省潜在的生产成本.佛罗里达州的部分甘蔗种植者多年来应用了IPM技术,该技术使用的杀虫剂见表1. 相似文献
116.
测定了几种污泥的化学特性并将3种污泥施用在盆栽和田间试验的作物上。污水处理厂和啤酒污泥中氮、磷、钾及有机质的含量远高于机械厂和化工厂的污泥。施用污水处理厂和啤酒污泥能分别增加盆栽油菜和田间棉花的产量;在提高棉花经济产量上,啤酒污泥与化学肥料具有等效作用。因而,污水处理厂和啤酒污泥可作为土壤改良剂并有利于作物生长。化工厂污泥中镉、铜、铅、锌含量都高于其它污泥,盆栽棉花对化工厂污泥的瓜在也因土壤类型而异,因而将化工厂污泥应用于作物生产会带来重金属的污染。 相似文献
117.
118.
Arianne P. Ori Danielle N. Silva Ana Cludia Raposo Alessandra Estrela‐Lima Thaís T. Pires Marco A. Gattamorta Roberta R. Zamana Eliana R. Matushima Ron Ofri 《Veterinary ophthalmology》2021,24(1):97-102
A captive loggerhead turtle (Caretta caretta) of unknown sex, 3 years of age, presented with bilateral mucoid secretions, severe chemosis, conjunctival hyperemia, and globe retraction. The animal was evaluated ophthalmologically and systemically, and hematological, microbiological, and conjunctival cytological and biopsy samples were collected for complementary diagnosis. The histopathological examination showed amphophilic intranuclear inclusions associated with severe inflammatory infiltrate. The diagnosis of Chelonid alphaherpesvirus 5 (ChAHV 5) was confirmed with end point PCR. Following systemic treatment with L‐lysine, acyclovir and vitamin A, the ocular signs resolved. No amphophilic intranuclear inclusions were seen in a follow‐up biopsy 5 months later, and there has been no recurrence of clinical ophthalmic signs during a 4‐year follow‐up. It is suggested that ChAHV 5 be considered as a differential diagnosis in captive marine turtles that present for conjunctival disease other than fibropapillomatosis. 相似文献
119.
Following application of fertiliser-N to the seedbed of potato crops, concentrations of extracted mineral-N were up to 3 times greater than would be anticipated by calculation. The rates at which both NO
3
–
-N and NH
4
+
-N apparently appeared and disappeared in the soil solution were, at various times, also much greater than could be attributable to any transformations resulting from microbial activity. This suggests that the involvement of other factors in this phenomenon must be considered. The effect of certain physical parameters such as water movement, resulting from capillary action and evaporation from the soil surface, may be implicated. We suggest that soil microbes are not directly involved in the early fate of fertiliser-N, primarily due to C-limitation in arable soils. N dynamics in fertilised potato systems require further studies targeting the relationships between nutrient concentrations in soil solution and mass flow of soil water. 相似文献
120.
Stintzing FC Herbach KM Mosshammer MR Carle R Yi W Sellappan S Akoh CC Bunch R Felker P 《Journal of agricultural and food chemistry》2005,53(2):442-451
Total phenolics, ascorbic acid, and betalain contents of differently colored cactus pear clones (nine Opuntia ficus-indica [L.] Mill. clones and one O. robusta Wendl. clone) were investigated and related to their respective antioxidant potential assessed by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. TEAC and ORAC values were very highly correlated with each other and also with values for total phenolics, betalain contents, and ascorbic acid concentrations. Total phenolics had the greatest contribution to ORAC and TEAC values. High-performance liquid chromatography (HPLC)-diode array detector (DAD)-tandem mass spectrometry (MS/MS) measurements of cactus pear juices permitted the differentiation of the clones based on variations in pigment patterns and betalain concentrations. The red and yellow betalains were absent in lime green colored cactus fruits. The ratio and concentration of these pigments were responsible for the yellow, orange, red, and purple colors in the other clones. Progeny of purple and lime green colored parents were characterized by 12% and 88% of plants bearing lime green and purple fruit, respectively. This implies that the genes for betalain production were lacking in the lime green fruits but could be provided by a parent with a complete set of genes, that is, purple fruits. Besides known pigments typical of Cactaceae, two unexpected betalains were identified. Whereas gomphrenin I was found for the first time in tissues of cactus plants, methionine-betaxanthin has never been described before as a genuine betalain. In addition to their alleged health-promoting properties, various combinations of yellow betaxanthins and red-purple betacyanins may allow the development of new food products without using artificial colorants. 相似文献