全文获取类型
收费全文 | 233篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
林业 | 5篇 |
农学 | 5篇 |
64篇 | |
综合类 | 21篇 |
农作物 | 16篇 |
水产渔业 | 11篇 |
畜牧兽医 | 109篇 |
园艺 | 1篇 |
植物保护 | 13篇 |
出版年
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 30篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 10篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1963年 | 4篇 |
1960年 | 3篇 |
1951年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 15 毫秒
241.
Kimberly L Kanapeckas Te‐Ming Tseng Cynthia C Vigueira Aida Ortiz William C Bridges Nilda R Burgos Albert J Fischer Amy Lawton‐Rauh 《Pest management science》2018,74(6):i-i
The cover image, by Kimberly L Kanapeckas et al., is based on the Research Article Contrasting patterns of variation in weedy traits and unique crop features in divergent populations of US weedy rice (Oryza sativa sp.) in Arkansas and California, DOI: 10.1002/ps.4820 . Photo Credit: Amy Lawton‐Rauh.
242.
Matsuzawa A Tseng PH Vallabhapurapu S Luo JL Zhang W Wang H Vignali DA Gallagher E Karin M 《Science (New York, N.Y.)》2008,321(5889):663-668
Cytokine signaling is thought to require assembly of multicomponent signaling complexes at cytoplasmic segments of membrane-embedded receptors, in which receptor-proximal protein kinases are activated. Indeed, CD40, a tumor necrosis factor receptor (TNFR) family member, forms a complex containing adaptor molecules TRAF2 and TRAF3, ubiquitin-conjugating enzyme Ubc13, cellular inhibitor of apoptosis proteins 1 and 2 (c-IAP1/2), IkappaB kinase regulatory subunit IKKgamma (also called NEMO), and mitogen-activated protein kinase (MAPK) kinase kinase MEKK1 upon ligation. TRAF2, Ubc13, and IKKgamma were required for complex assembly and activation of MEKK1 and MAPK cascades. However, these kinases were not activated unless the multicomponent signaling complex translocated from CD40 to the cytosol upon c-IAP1/2-induced degradation of TRAF3. This two-stage signaling mechanism may apply to other innate immune receptors, accounting for spatial and temporal separation of MAPK and IKK signaling. 相似文献
243.
Wen-Liang Lai Lih-Fu Chen Shao-Wei Liao Shu-Lin Hsu Li-Ho Tseng Chang-Ling Miaw 《Water, air, and soil pollution》2007,186(1-4):43-53
This study conducted a two-stage experiment. The first stage attempted to establish biostable filter beds. Two parameters, total bacterial count (TBC) and non-purgeable dissolved carbon (NPDOC), measured by passing through a 0.2 μm membrane filter, were selected to compare the difference of biostability of a filtration system with recirculation with different O3-to-NPDOC ratios of filtered water. The excitation emission fluorescence matrix (EEFM) was used as an effective tool for understanding information regarding organic characteristics by comparing source filtered water before and after ozonation and the effluent during biostablizing filter. During the second stage, a biostable filter was used to compare differences in biodegradability of ozonated products sodium oxalate and sodium acetate. Experimental results demonstrate that both parameters, NPDOC removal and TBC, can be utilized to evaluate the biostabilty of a filter bed. With each parameter, a plateau was reached in roughly 20 days. The source water from Chen Ching Lake (CCL) contained a protein-like substance determined by the EEFM. This protein-like substance was also destroyed by O3/NPDOC?=?1.1. Soluble microbial products (SMPs) released from the biostablizing filter into the effluent have two peaks in the EEFM, identified as protein-like and humic-like acid. The NPDOC removal for the biostabilizing filter using O3/NPDOC?=?1.7 was less than that using O3/NPDOC?=?1.1. Bacterial counts in the effluent from the biostabilizing filter using O3/NPDOC?=?1.1 was better than that of O3/NPDOC?=?1.7. This difference can be explained by the high ratio of O3/NPDOC producing by-products of ozonation that were easily utilized by microorganisms; however, filter bed also released relatively more SMPs owing to increased proliferation of microorganisms attached to glass pellets in the filter. Regarding the differences in decomposition of the by-products of ozonation by the biostable filter, such as sodium oxalate, the NPDOC removal at O3/NPDOC?=?1.1 was better than that at O3/DOC?=?1.7. This phenomenon can be explained as previously mentioned. 相似文献
244.
Swartz TE Tseng TS Frederickson MA Paris G Comerci DJ Rajashekara G Kim JG Mudgett MB Splitter GA Ugalde RA Goldbaum FA Briggs WR Bogomolni RA 《Science (New York, N.Y.)》2007,317(5841):1090-1093
Histidine kinases, used for environmental sensing by bacterial two-component systems, are involved in regulation of bacterial gene expression, chemotaxis, phototaxis, and virulence. Flavin-containing domains function as light-sensory modules in plant and algal phototropins and in fungal blue-light receptors. We have discovered that the prokaryotes Brucella melitensis, Brucella abortus, Erythrobacter litoralis, and Pseudomonas syringae contain light-activated histidine kinases that bind a flavin chromophore and undergo photochemistry indicative of cysteinyl-flavin adduct formation. Infection of macrophages by B. abortus was stimulated by light in the wild type but was limited in photochemically inactive and null mutants, indicating that the flavin-containing histidine kinase functions as a photoreceptor regulating B. abortus virulence. 相似文献
245.
Yun-Jie Xio Jui-Hsin Su Yen-Ju Tseng Bo-Wei Chen Wangta Liu Jyh-Horng Sheu 《Marine drugs》2014,12(8):4495-4503
Five sesquiterpene-related metabolites (1–5), including two new eremophilane-type compounds, philippinlins C and D (1 and 2) and a 4,5-seconeolemnane philippinlin E (3), were isolated from the organic extract of a Taiwanese soft coral Lemnalia philippinensis. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis and by comparison of NMR data with those of related metabolites. Compound 3 was suggested to be derived from the neolemnane skeleton. 相似文献