全文获取类型
收费全文 | 25930篇 |
免费 | 2417篇 |
国内免费 | 2695篇 |
专业分类
31042篇 |
出版年
2024年 | 90篇 |
2023年 | 416篇 |
2022年 | 881篇 |
2021年 | 1403篇 |
2020年 | 984篇 |
2019年 | 1218篇 |
2018年 | 1114篇 |
2017年 | 882篇 |
2016年 | 1130篇 |
2015年 | 1645篇 |
2014年 | 1900篇 |
2013年 | 2034篇 |
2012年 | 2438篇 |
2011年 | 2188篇 |
2010年 | 1347篇 |
2009年 | 1201篇 |
2008年 | 1459篇 |
2007年 | 1266篇 |
2006年 | 1135篇 |
2005年 | 992篇 |
2004年 | 847篇 |
2003年 | 830篇 |
2002年 | 692篇 |
2001年 | 467篇 |
2000年 | 393篇 |
1999年 | 342篇 |
1998年 | 213篇 |
1997年 | 200篇 |
1996年 | 186篇 |
1995年 | 138篇 |
1994年 | 181篇 |
1993年 | 117篇 |
1992年 | 111篇 |
1991年 | 113篇 |
1990年 | 98篇 |
1989年 | 75篇 |
1988年 | 62篇 |
1987年 | 39篇 |
1986年 | 40篇 |
1985年 | 50篇 |
1984年 | 30篇 |
1983年 | 35篇 |
1982年 | 23篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1973年 | 4篇 |
1971年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
Karnpiwat Tantratian Daxian Cao Ahmed Abdelaziz Xiao Sun Jinzhi Sheng Avi Natan Lei Chen Hongli Zhu 《Liver Transplantation》2020,10(5)
The application of lithium (Li) metal anodes in rechargeable batteries is primarily restricted by Li dendrite growth on the metal's surface, which leads to shortened cycle life and safety concerns. Herein, well‐spaced nanotubes with ultrauniform surface curvature are introduced as a Li metal anode structure. The ultrauniform nanotubular surface generates uniform local electric fields that evenly attract Li‐ions to the surface, thereby inducing even current density distribution. Moreover, the well‐defined nanotube spacing offers Li diffusion pathways to the electroactive areas as well as the confined spaces to host deposited Li. These structural attributes create a unique electrodeposition manner; i.e., Li metal homogenously deposits on the nanotubular wall, causing each Li nanotube to grow in circumference without obvious sign of dendritic formation. Thus, the full‐cell battery with the spaced Li nanotubes exhibits a high specific capacity of 132 mA h g?1 at 1 C and an excellent coulombic efficiency of ≈99.85% over 400 cycles. 相似文献
64.
65.
Yi Tan Lingchao Miao Jianbo Xiao Wai San Cheang 《Current issues in molecular biology》2022,44(5):2175
The potential anti-diabetic effect of resveratrol derivative, 3,3′,4,5′-tetramethoxy-trans-stilbene (3,3′,4,5′-TMS) and its underlying mechanism in high glucose (HG) and dexamethasone (DXMS)-stimulated insulin-resistant HepG2 cells (IR-HepG2) were investigated. 3,3′,4,5′-TMS did not reduce the cell viability of IR-HepG2 cells at the concentrations of 0.5–10 µM. 3,3′,4,5′-TMS increased the potential of glucose consumption and glycogen synthesis in a concentration-dependent manner in IR-HepG2 cells. 3,3′,4,5′-TMS ameliorated insulin resistance by enhancing the phosphorylation of glycogen synthase kinase 3 beta (GSK3β), inhibiting phosphorylation of insulin receptor substrate-1 (IRS-1), and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in IR-HepG2 cells. Furthermore, 3,3′,4,5′-TMS significantly suppressed levels of reactive oxygen species (ROS) with up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression. To conclude, the beneficial effect of 3,3′,4,5′-TMS against insulin resistance to increase glucose consumption and glycogen synthesis was mediated through activation of IRS/PI3K/Akt signaling pathways in the IR-HepG2 cells, accomplished with anti-oxidative activity through up-regulation of Nrf2. 相似文献
66.
67.
68.
69.
Yan-Ru Cao Yi Jiang Qian Wang Shu-Kun Tang Wen-Xiang He Quan-Hong Xue Li-Hua Xu Cheng-Lin Jiang 《Antonie van Leeuwenhoek》2010,98(3):389-394
A novel pink-coloured, non-spore-forming, non-motile, Gram-negative bacterium, designated YIM 48858T, is described by using a polyphasic approach. The strain can grow at pH 6.5–9 (optimum at pH 7) and 25–30°C (optimum at 28°C).
NaCl is not required for its growth. Positive for oxidase and catalase. Urease activity, nitrate reduction, starch and Tween
80 tests are negative reaction. 16S rRNA gene sequence similarity studies showed that strain YIM 48858T is a member of the genus Rubellimicrobium, with similarities of 96.3, 95.7 and 95.5% to Rubellimicrobium mesophilum MSL-20T, Rubellimicrobium aerolatum 5715S-9T and Rubellimicrobium
thermophilum DSM 16684T, respectively. Q-10 was the predominant respiratory ubiquinone as in the other members of the genus Rubellimicrobium. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphoglycolipid, glycolipid and the major fatty
acids were C18:1 ω7c, C16:0 and C10:0 3-OH, which are very different from the valid published species. The DNA G + C content
was 67.7 mol%. Both phylogenetic and chemotaxonomic evidence supports that YIM 48858T is a novel species of the genus Rubellimicrobium, for which the name Rubellimicrobium roseum sp. nov. is proposed. The type strain is YIM 48858T (=CCTCC AA 208029T =KCTC 23202T). 相似文献
70.
Li Huang Yiqun Ye Yuchao Zhang Aihong Zhang Tingting Liu Jiashu Cao 《Annals of botany》2009,104(7):1339-1351