全文获取类型
收费全文 | 4341篇 |
免费 | 108篇 |
国内免费 | 5篇 |
学科分类
工业技术 | 4454篇 |
出版年
2021年 | 39篇 |
2020年 | 31篇 |
2019年 | 38篇 |
2018年 | 37篇 |
2017年 | 40篇 |
2016年 | 57篇 |
2015年 | 54篇 |
2014年 | 81篇 |
2013年 | 248篇 |
2012年 | 146篇 |
2011年 | 176篇 |
2010年 | 156篇 |
2009年 | 175篇 |
2008年 | 203篇 |
2007年 | 195篇 |
2006年 | 182篇 |
2005年 | 136篇 |
2004年 | 128篇 |
2003年 | 107篇 |
2002年 | 124篇 |
2001年 | 87篇 |
2000年 | 82篇 |
1999年 | 64篇 |
1998年 | 67篇 |
1997年 | 61篇 |
1996年 | 63篇 |
1995年 | 84篇 |
1994年 | 76篇 |
1993年 | 77篇 |
1992年 | 91篇 |
1991年 | 33篇 |
1990年 | 69篇 |
1989年 | 57篇 |
1988年 | 61篇 |
1987年 | 67篇 |
1986年 | 66篇 |
1985年 | 89篇 |
1984年 | 86篇 |
1983年 | 81篇 |
1982年 | 83篇 |
1981年 | 74篇 |
1980年 | 45篇 |
1979年 | 61篇 |
1978年 | 60篇 |
1977年 | 54篇 |
1976年 | 52篇 |
1975年 | 64篇 |
1974年 | 38篇 |
1973年 | 39篇 |
1972年 | 32篇 |
排序方式: 共有4454条查询结果,搜索用时 31 毫秒
1.
2.
3.
Dr. Louise M. Sternicki Dr. Jim Nonomiya Dr. Miaomiao Liu Dr. Melinda M. Mulvihill Dr. Ronald J. Quinn 《ChemMedChem》2021,16(14):2206-2210
PRO teolysis TA rgeting C himeras (PROTACs) promote the degradation, rather than inhibition, of a drug target as a mechanism for therapeutic treatment. Bifunctional PROTAC molecules allow simultaneous binding of both the target protein and an E3-Ubiquitin ligase, bringing the two proteins into close spatial proximity to allow ubiquitinylation and degradation of the target protein via the cell's endogenous protein degradation pathway. We utilized native mass spectrometry (MS) to study the ternary complexes promoted by the previously reported PROTAC GNE-987 between Brd4 bromodomains 1 and 2, and Von Hippel Lindeau E3-Ubiquitin Ligase. Native MS at high resolution allowed us to measure ternary complex formation as a function of PROTAC concentration to provide a measure of complex affinity and stability, whilst simultaneously measuring other intermediate protein species. Native MS provides a high-throughput, low sample consumption, direct screening method to measure ternary complexes for PROTAC development. 相似文献
4.
Anna M. Schoepf Dr. Stefan Salcher Verena Hohn Florina Veider Prof. Dr. Petra Obexer Prof. Dr. Ronald Gust 《ChemMedChem》2020,15(12):1067-1077
New strategies to eradicate cancer stem cells in chronic myeloid leukemia (CML) include a combination of imatinib with peroxisome proliferator-activated receptor gamma (PPARγ) ligands. Recently, we identified the partial PPARγ agonist telmisartan as effective sensitizer of resistant K562 CML cells to imatinib treatment. Here, the importance of the heterocyclic core on the cell death-modulating effects of the telmisartan-derived lead 4′-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1′-biphenyl]-2-carboxylic acid ( 3 b ) was investigated. Inspired by the pharmacodynamics of HYL-6d and the selective PPARγ ligand VSP-51, the benzimidazole was replaced by a carbazole or an indole core. The results indicate no correlation between PPARγ activation and sensitization of resistant CML cells to imatinib. The 2-COOH derivatives of the carbazoles or indoles achieved low activity at PPARγ, while the benzimidazoles showed 60-100 % activation. Among the 2-CO2CH3 derivatives, only the ester of the lead ( 2 b ) slightly activated PPARγ. Sensitizing effects were further observed for this non-cytotoxic 2 b (80 % cell death), and to a lesser extent for the lead 3 b or the 5-Br-substituted ester of the benzimidazoles ( 5 b ). 相似文献
5.
Lihua Lou Weijie Yu Ronald J. Kendall Ernest Smith Seshadri S. Ramkumar 《应用聚合物科学杂志》2020,137(30):49213
A tensile properties testing study was conducted to understand the influence of thickness, cross-head speed (speed of testing), gauge length (GL; specimen test length), and sample shape on important tensile properties of polyvinyl alcohol (PVA) nanofiber webs. The effects of each testing parameter on load at break, extension at break, Young's modulus, and tensile stress–strain curve of PVA nanofiber webs are analyzed. The Welch two sample t-tests show the significant difference among tested data. Using interaction plots, two-way analysis of variance, and margin mean plots, the interaction effects among testing parameters have been analyzed. Of all the factors, cross-head speed, the interaction among GL, and sample thickness (GL: Thickness) and the interaction among GL, testing speed and sample thickness (GL: Speed: Thickness) have significant influence on the tensile properties of PVA nanofiber webs. Moreover, the hypothesized model of mechanism of tensile strain–stress curve of PVA nanofiber webs has been proposed. Based on the model, the tensile strain–stress curve can be split into three stages: linear elastic, partial break up, and complete breakage. This study will provide a better understanding of tensile testing parameters' effects and their interaction effects on the tensile properties of nanowebs. 相似文献
6.
7.
Scott J. Robertson Marina B. Ruggles-Wrenn Randall S. Hay Theodore Shillig Ronald Mitchell Brian Kroeger Logan Gumucio 《Journal of the American Ceramic Society》2020,103(2):1358-1371
A facility for testing SiC fiber tows in static fatigue and creep at elevated temperatures in air and steam was developed. Static fatigue of Hi-Nicalon™-S fibers was investigated at 800°C-1100°C at applied stresses between 115 and 1250 MPa in air, in Si(OH)4(g)-saturated steam, and in unsaturated steam. Fibers tested in Si(OH)4(g)-saturated steam and in air had silica scales throughout the test sections, but those tested in unsaturated steam did not develop scales near the steam injection point. Fiber lifetimes in static fatigue were shortest in unsaturated steam, intermediate in Si(OH)4(g)-saturated steam, and longest in air. Failure strains did not exceed 0.3%. Steady-state strain rates and static fatigue lifetimes are modelled empirically by the Monkman-Grant relationship. Failure mechanisms are discussed. 相似文献
8.
9.
10.
Scientometrics - This article provides an overview of the development of the h-index formalism. We begin with the original formulation as provided by Hirsch and move on to the latest versions. In... 相似文献