全文获取类型
收费全文 | 283790篇 |
免费 | 5059篇 |
国内免费 | 484篇 |
专业分类
电工技术 | 4605篇 |
综合类 | 296篇 |
化学工业 | 49003篇 |
金属工艺 | 10181篇 |
机械仪表 | 8238篇 |
建筑科学 | 6780篇 |
矿业工程 | 1481篇 |
能源动力 | 6294篇 |
轻工业 | 32159篇 |
水利工程 | 2861篇 |
石油天然气 | 5270篇 |
武器工业 | 39篇 |
无线电 | 26717篇 |
一般工业技术 | 51280篇 |
冶金工业 | 53750篇 |
原子能技术 | 6165篇 |
自动化技术 | 24214篇 |
出版年
2022年 | 2104篇 |
2021年 | 3313篇 |
2020年 | 2348篇 |
2019年 | 3045篇 |
2018年 | 4950篇 |
2017年 | 4884篇 |
2016年 | 5283篇 |
2015年 | 3489篇 |
2014年 | 5467篇 |
2013年 | 13295篇 |
2012年 | 8581篇 |
2011年 | 10893篇 |
2010年 | 8578篇 |
2009年 | 9186篇 |
2008年 | 9349篇 |
2007年 | 9289篇 |
2006年 | 8102篇 |
2005年 | 7109篇 |
2004年 | 6787篇 |
2003年 | 6478篇 |
2002年 | 6467篇 |
2001年 | 6114篇 |
2000年 | 5947篇 |
1999年 | 5899篇 |
1998年 | 15132篇 |
1997年 | 10632篇 |
1996年 | 8025篇 |
1995年 | 6038篇 |
1994年 | 5313篇 |
1993年 | 5273篇 |
1992年 | 3918篇 |
1991年 | 3633篇 |
1990年 | 3766篇 |
1989年 | 3662篇 |
1988年 | 3496篇 |
1987年 | 3067篇 |
1986年 | 3072篇 |
1985年 | 3561篇 |
1984年 | 3377篇 |
1983年 | 3007篇 |
1982年 | 2882篇 |
1981年 | 2974篇 |
1980年 | 2878篇 |
1979年 | 2708篇 |
1978年 | 2771篇 |
1977年 | 3255篇 |
1976年 | 4464篇 |
1975年 | 2435篇 |
1974年 | 2295篇 |
1973年 | 2449篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
Lissy Z. F. Gross Mariana Sacerdoti Prof. Albrecht Piiper Prof. Stefan Zeuzem Dr. Alejandro E. Leroux Dr. Ricardo M. Biondi 《ChemMedChem》2020,15(18):1682-1690
Angiotensin converting enzyme 2 (ACE2) is the human receptor that interacts with the spike protein of coronaviruses, including the one that produced the 2020 coronavirus pandemic (COVID-19). Thus, ACE2 is a potential target for drugs that disrupt the interaction of human cells with SARS-CoV-2 to abolish infection. There is also interest in drugs that inhibit or activate ACE2, that is, for cardiovascular disorders or colitis. Compounds binding at alternative sites could allosterically affect the interaction with the spike protein. Herein, we review biochemical, chemical biology, and structural information on ACE2, including the recent cryoEM structures of full-length ACE2. We conclude that ACE2 is very dynamic and that allosteric drugs could be developed to target ACE2. At the time of the 2020 pandemic, we suggest that available ACE2 inhibitors or activators in advanced development should be tested for their ability to allosterically displace the interaction between ACE2 and the spike protein. 相似文献
23.
24.
25.
26.
27.
Dr. Raysa Khan Tareque Dr. Storm Hassell-Hart Dr. Tobias Krojer Dr. Anthony Bradley Dr. Srikannathasan Velupillai Dr. Romain Talon Dr. Michael Fairhead Dr. Iain J. Day Kamlesh Bala Dr. Robert Felix Dr. Paul D. Kemmitt Prof. Paul Brennan Prof. Frank von Delft Dr. Laura Díaz Sáez Prof. Kilian Huber Prof. John Spencer 《ChemMedChem》2020,15(24):2513-2520
Combined photochemical arylation, “nuisance effect” (SNAr) reaction sequences have been employed in the design of small arrays for immediate deployment in medium-throughput X-ray protein–ligand structure determination. Reactions were deliberately allowed to run “out of control” in terms of selectivity; for example the ortho-arylation of 2-phenylpyridine gave five products resulting from mono- and bisarylations combined with SNAr processes. As a result, a number of crystallographic hits against NUDT7, a key peroxisomal CoA ester hydrolase, have been identified. 相似文献
28.
29.
Alexandra Kodadová Zuzana Vitková Petra Herdová Anton Ťažký Jarmila Oremusová Daniel Grančai 《Drug development and industrial pharmacy》2015,41(7):1080-1088
This study deals with the formulation of natural drugs into hydrogels. For the first time, compounds from the sage essential oil were formulated into chitosan hydrogels. A sample preparation procedure for hydrophobic volatile analytes present in a hydrophilic water matrix along with an analytical method based on the gas chromatography coupled with the mass spectrometry (GC-MS) was developed and applied for the evaluation of the identity and quantity of essential oil components in the hydrogels and saline samples. The experimental results revealed that the chitosan hydrogels are suitable for the formulation of sage essential oil. The monoterpene release can be effectively controlled by both chitosan and caffeine concentration in the hydrogels. Permeation experiment, based on a hydrogel with the optimized composition [3.5% (w/w) sage essential oil, 2.0% (w/w) caffeine, 2.5% (w/w) chitosan and 0.1% (w/w) Tween-80] in donor compartment, saline solution in acceptor compartment, and semi-permeable cellophane membrane, demonstrated the useful permeation selectivity. Here, (according to lipophilicity) an enhanced permeation of the bicyclic monoterpenes with antiflogistic and antiseptic properties (eucalyptol, camphor and borneol) and, at the same time, suppressed permeation of toxic thujone (not exceeding its permitted applicable concentration) was observed. These properties highlight the pharmaceutical importance of the developed chitosan hydrogel formulating sage essential oil in the dermal applications. 相似文献
30.