全文获取类型
收费全文 | 9098篇 |
免费 | 988篇 |
国内免费 | 622篇 |
专业分类
林业 | 627篇 |
农学 | 457篇 |
基础科学 | 362篇 |
913篇 | |
综合类 | 4776篇 |
农作物 | 634篇 |
水产渔业 | 430篇 |
畜牧兽医 | 1374篇 |
园艺 | 738篇 |
植物保护 | 397篇 |
出版年
2025年 | 3篇 |
2024年 | 193篇 |
2023年 | 186篇 |
2022年 | 444篇 |
2021年 | 390篇 |
2020年 | 389篇 |
2019年 | 402篇 |
2018年 | 259篇 |
2017年 | 447篇 |
2016年 | 276篇 |
2015年 | 452篇 |
2014年 | 464篇 |
2013年 | 554篇 |
2012年 | 769篇 |
2011年 | 864篇 |
2010年 | 785篇 |
2009年 | 707篇 |
2008年 | 640篇 |
2007年 | 600篇 |
2006年 | 515篇 |
2005年 | 404篇 |
2004年 | 288篇 |
2003年 | 148篇 |
2002年 | 157篇 |
2001年 | 151篇 |
2000年 | 120篇 |
1999年 | 32篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1981年 | 1篇 |
1965年 | 1篇 |
1962年 | 2篇 |
1960年 | 1篇 |
1956年 | 5篇 |
1955年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
131.
132.
133.
134.
135.
136.
蓝光对水稻幼苗叶绿体发育的影响 总被引:14,自引:0,他引:14
蓝光对水稻幼苗叶绿体发育的影响李韶山,潘瑞炽(华南师范大学广州510631)关键词:蓝光,叶绿体,黄化质体,转绿,类囊体EffectofBlueLightontheDevelopmentofChloroplastsinRiceSeedlings¥LI... 相似文献
137.
AIM: To investigate the neuroprotective effect of erythropoietin (EPO) on cognitive dysfunction and neuronal injury in hippocampal CA1 region induced by cerebral ischemia in mice. METHODS: Male C57BL/6 green fluorescent protein-transgenic mice were randomly divided into 3 groups: sham operation group (sham), ischemia/reperfusion group (I/R) and EPO-treated group. Transient cerebral global ischemia was induced by bilateral common carotid artery occlusion (2-VO). The step-down test was used to measure the capacity of learning and memory of the animals in each group. Nissl staining was applied to examine the neuronal number in hippocampal CA1 region. The expression of phosphorylated cAMP response element-binding protein (pCREB) was determined by Western blotting. Alterations of dendritic morphology in hippocampal CA1 region were evaluated using laser scanning confocal microscopy and Neurolucida software. RESULTS: Transient cerebral ischemia caused deficits of spatial learning and memory, and delayed neuronal death and loss of dendritic spines in hippocampal CA1 region were also obvious. The EPO treatment significantly improved the cognitive function in cerebral ischemic mice, and the protein expression of pCREB was obviously increased. At the same time, neuronal death and loss of dendritic spines were reduced in hippocampal CA1 region. CONCLUSION: Erythropoietin increases the protein expression of pCREB, and reduces neuronal death and loss of dendritic spines. These processes may be responsible for erythropoietin-mediated neuroprotective effects and the improvement of cognitive function in cerebral ischemic mice. 相似文献
138.
从道路绿化对交通安全的影响、植物配置和交通安全的关系着手,研究了各种类型道路中通过植物配置来促进交通安全的方法。 相似文献
139.
WAN Jian-xin GUO Qi WANG Jing-han PAN Yang-bin CUI Jiong FU Bin-bin XU Yan-fang 《园艺学报》2009,25(8):1628-1634
AIM: To observe the effects of cytokines on renovation of acute renal failure (ARF) in mouse with bone marrow derived mesenchymal stem cell (MSC) transplantation. METHODS: ARF animal model was induced in mouse by subcutaneous injection of cisplatin. Mice were randomly assigned into 3 groups: normal control group, ARF group and MSC group. After 24 h cisplatin injection, animals were injected intravenously with MSC in MSC group. Animals were sacrificed at 1 d, 4 d, 7 d, 14 d and 28 d after cisplatin injection. The blood urea nitrogen (BUN) and serum creatinine (Scr) were measured. The renal morphologic changes were scored with Paller’s criterion on hematoxylin and eosin (HE) stained sections. The mRNA and protein expressions of HGF, BMP-7, TNF-α and IL-10 were detected by RT-PCR and immunohistochemistry method. RESULTS: After 4 d of cisplatin injection, the BUN and Scr values in MSC group were significantly lower than those in ARF group (P<0.01). After 7 d and 14 d, the values of BUN and Scr in MSC group were still lower than those in ARF group (P<0.01, P<0.05). The renal morphologic scores of MSC group were also lower than those of ARF group. After 7 d, the expressions of HGF, BMP-7 and IL-10 were higher in MSC group than those in ARF group, the expression of TNF-α in MSC group was lower than that in ARF group. CONCLUSION: MSC promotes the recovery of acute renal failure induced by cisplatin. The mechanism may partly depend on paracrine of growth factor and amelioration of inflammatory. 相似文献
140.
Studies were given to the induction and growth of callus of Aloe vera L.var.chinensis(Haw.) Berg when the young stem was applied as explant.MS was taken as basic medium,added with various concentrations of auxins(IAA,IBA,NAA and 2,4-D),cytokinins(6-BA,KT and Zeatin) and the different combinations of these plant growth regulators.Results showed that the callus is barely induced by cytokinin alone,and the callus induction rates have significant difference when different concentrations of auxin and different combinations of auxin with cytokinin are used on the MS medium.In order to inhibit callus browning during culturing,various concentrations of vitamin C or active carbon are added into four combinations of auxin and cytokinin respectively,which can induce callus most effectively.The result showsd that vitamin C can alleviate callus browning more effectively than the active carbon.The most efficient medium for induction and growth of callus of Aloe vera L.var.chinensis(Haw.) Berg was MS+2.0 mg/L 6-BA+0.5 mg/L 2,4-D+10 mg/ L vitamin C,with which the callus induction rate can reach to 91.4% and callus grow vigorously. 相似文献