全文获取类型
收费全文 | 2232篇 |
免费 | 297篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
综合类 | 2篇 |
化学工业 | 757篇 |
金属工艺 | 59篇 |
机械仪表 | 79篇 |
建筑科学 | 30篇 |
能源动力 | 60篇 |
轻工业 | 510篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 326篇 |
一般工业技术 | 456篇 |
冶金工业 | 62篇 |
原子能技术 | 13篇 |
自动化技术 | 165篇 |
出版年
2024年 | 4篇 |
2023年 | 39篇 |
2022年 | 87篇 |
2021年 | 130篇 |
2020年 | 81篇 |
2019年 | 89篇 |
2018年 | 98篇 |
2017年 | 119篇 |
2016年 | 130篇 |
2015年 | 112篇 |
2014年 | 158篇 |
2013年 | 147篇 |
2012年 | 175篇 |
2011年 | 232篇 |
2010年 | 175篇 |
2009年 | 132篇 |
2008年 | 122篇 |
2007年 | 82篇 |
2006年 | 57篇 |
2005年 | 69篇 |
2004年 | 56篇 |
2003年 | 44篇 |
2002年 | 32篇 |
2001年 | 19篇 |
2000年 | 22篇 |
1999年 | 14篇 |
1998年 | 13篇 |
1997年 | 20篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1984年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有2531条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
In vivo Kinetic Biodistribution of Nano‐Sized Outer Membrane Vesicles Derived from Bacteria 下载免费PDF全文
Su Chul Jang Sae Rom Kim Yae Jin Yoon Kyong‐Su Park Ji Hyun Kim Jaewook Lee Oh Youn Kim Eun‐Jeong Choi Dae‐Kyum Kim Dong‐Sic Choi Yoon‐Keun Kim Jaesung Park Dolores Di Vizio Yong Song Gho 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(4):456-461
Evaluation of kinetic distribution and behaviors of nanoparticles in vivo provides crucial clues into their roles in living organisms. Extracellular vesicles are evolutionary conserved nanoparticles, known to play important biological functions in intercellular, inter‐species, and inter‐kingdom communication. In this study, the first kinetic analysis of the biodistribution of outer membrane vesicles (OMVs)—bacterial extracellular vesicles—with immune‐modulatory functions is performed. OMVs, injected intraperitoneally, spread to the whole mouse body and accumulate in the liver, lung, spleen, and kidney within 3 h of administration. As an early systemic inflammation response, increased levels of TNF‐α and IL‐6 are observed in serum and bronchoalveolar lavage fluid. In addition, the number of leukocytes and platelets in the blood is decreased. OMVs and cytokine concentrations, as well as body temperature are gradually decreased 6 h after OMV injection, in concomitance with the formation of eye exudates, and of an increase in ICAM‐1 levels in the lung. Following OMV elimination, most of the inflammatory signs are reverted, 12 h post‐injection. However, leukocytes in bronchoalveolar lavage fluid are increased as a late reaction. Taken together, these results suggest that OMVs are effective mediators of long distance communication in vivo. 相似文献
5.
6.
7.
8.
Ha-Nul Lee Joo-Hee Choi Ji-Yeon Park Jae-Hun Ahn Da Eun Jang Jae Gun Shim Jong-Hwan Park Young-Min Kim 《Food science and biotechnology》2021,30(4):583
Vegetable soup (VS), a plant-based functional food, has been used as a traditional folk medicine and is attracting attention for its ability to enhance the immune response. β-Glucan, a well-established and effective immunomodulator, has synergistic effects when used in combination with some bioactive compounds. In the present study, we aimed to evaluate the synergistic immunomodulatory effects of the combination of VS and β-glucan on macrophage-mediated immune responses. β-Glucan was demonstrated to synergistically enhance the VS-stimulated immune response, including the production of interleukin-6, tumor necrosis factor-α, and nitric oxide, mainly through the mitogen-activated protein kinase pathway in macrophages. In addition, this combination has the potential for further development in functional foods with immune-enhancing activity.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10068-021-00888-x. 相似文献
9.
Chuang-Yuan Lee Eun Sok Kim 《Journal of microelectromechanical systems》2006,15(4):745-755
This paper describes the design, fabrication, and characterization of the first MEMS piezoelectric tunable capacitors employing zinc oxide (ZnO) actuation. Relatively simple design rules for the device-structure optimization for largest deflection are shown from simulation results based on theoretical equations. The ZnO-actuated tunable capacitors are accordingly designed and fabricated with both surface and bulk micromachining techniques. Through the surface micromachining process, sacrificial silicon is removed with XeF/sub 2/, and parylene is successfully used as a supporting layer for a piezoelectric unimorph cantilever. For comparison, other two different structures using plasma-enhanced chemical-vapor deposition (PECVD) SiN and SU-8 as supporting layers are also fabricated. Deflection analyses are performed for three specific structures, among which the parylene-supported one is demonstrated to have the largest displacement and most suitable for tunable capacitor application. For bulk-micromachined tunable capacitor, we have implemented a novel design of a large structure driven by a ZnO unimorph, and obtained a tuning ratio of more than 21:1 (0.46 pF-10.02 pF). This is the highest tuning ratio reported to date for parallel-plate tunable capacitors while requiring an applied voltage of only 35 V. 相似文献
10.
The transmission mode of holographic polymer‐dispersed liquid crystals (HPDLCs) was developed an under electric field. It is reported that orientation of LC molecules under an electric field induces orientation of oligomer molecules giving rise to low off‐state diffraction and small grating shrinkage. Copyright © 2005 Society of Chemical Industry 相似文献