全文获取类型
收费全文 | 1134篇 |
免费 | 67篇 |
专业分类
电工技术 | 19篇 |
综合类 | 17篇 |
化学工业 | 301篇 |
金属工艺 | 13篇 |
机械仪表 | 13篇 |
建筑科学 | 86篇 |
矿业工程 | 12篇 |
能源动力 | 14篇 |
轻工业 | 229篇 |
水利工程 | 18篇 |
石油天然气 | 2篇 |
无线电 | 37篇 |
一般工业技术 | 209篇 |
冶金工业 | 74篇 |
原子能技术 | 2篇 |
自动化技术 | 155篇 |
出版年
2024年 | 3篇 |
2023年 | 17篇 |
2022年 | 38篇 |
2021年 | 60篇 |
2020年 | 31篇 |
2019年 | 25篇 |
2018年 | 43篇 |
2017年 | 38篇 |
2016年 | 46篇 |
2015年 | 40篇 |
2014年 | 44篇 |
2013年 | 74篇 |
2012年 | 57篇 |
2011年 | 96篇 |
2010年 | 50篇 |
2009年 | 41篇 |
2008年 | 81篇 |
2007年 | 64篇 |
2006年 | 43篇 |
2005年 | 53篇 |
2004年 | 35篇 |
2003年 | 31篇 |
2002年 | 23篇 |
2001年 | 22篇 |
2000年 | 13篇 |
1999年 | 17篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1978年 | 2篇 |
1972年 | 1篇 |
1922年 | 1篇 |
排序方式: 共有1201条查询结果,搜索用时 14 毫秒
31.
Susanne Jung Marco Maria Moser Johannes Kleinheinz Arndt Happe 《International journal of molecular sciences》2021,22(14)
Gingivafibroblasts were cultured on lithium disilicate, on zirconia dioxide, and on titanium with two different surface roughnesses (0.2 µm and 0.07 µm); Proliferation (MTT), Living/Dead staining, cytotoxicity (LDH), proliferation (FGF2), and inflammation (TNFα) were analyzed after 1 day and 21 days. Furthermore, alteration in cell morphology (SEM) was analyzed. The statistical analysis was performed by a Kruskal–Wallis test. The level of significance was set at p < 0.05. There were no distinct differences in cellular behavior between the tested roughness. There were slight differences between tested materials. Cells grown on zirconia dioxide showed higher cytotoxic effects. Cells grown on lithium disilicate showed less expression of TNFα compared to those grown on zirconia dioxide or titanium. These effects persisted only during the first time span. The results indicate that the two tested high-strength ceramics and surface properties are biologically suitable for transmucosal implant components. The findings may help clinicians to choose the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications. 相似文献
32.
Summary
Poly(2-vinylthiophene) (PVT) can be cross linked with FeCl3 either in dichloromethane solution or when immobilized on silica particles. Extend of cross linking is strongly dependent on the FeCI3/PVT ratio used for the reaction as shown by GPC plots and gravimetric analyses of the formed insoluble polymer fraction. A stoichiometric FeCl3/PVT ratio of about four is necessary to achieve complete conversion, because consecutive formations of thiophene H+FeCl4
- and bisthiophene H+FeCl4
- sigma complexes take place. PVT can be also cross linked when adsorbed on silica using the same procedure. The cross-linking is proved by IR and 13C CPiMAS NMR spectroscopy. 相似文献
33.
34.
35.
Dr. Kornelia Hardes Dr. Gero L. Becker Dr. Yinghui Lu Dr. Sven O. Dahms Susanne Köhler Dr. Wolfgang Beyer Prof. Kirsten Sandvig Dr. Hiroyuki Yamamoto Prof. Iris Lindberg Lisa Walz Dr. Veronika von Messling Dr. Manuel E. Than Prof. Wolfgang Garten Prof. Torsten Steinmetzer 《ChemMedChem》2015,10(7):1218-1231
New peptidomimetic furin inhibitors with unnatural amino acid residues in the P3 position were synthesized. The most potent compound 4‐guanidinomethyl‐phenylacteyl‐Arg‐Tle‐Arg‐4‐amidinobenzylamide (MI‐1148) inhibits furin with a Ki value of 5.5 pM . The derivatives also strongly inhibit PC1/3, whereas PC2 is less affected. Selected inhibitors were tested in cell culture for antibacterial and antiviral activity against infectious agents known to be dependent on furin activity. A significant protective effect against anthrax and diphtheria toxin was observed in the presence of the furin inhibitors. Furthermore, the spread of the highly pathogenic H5N1 and H7N1 avian influenza viruses and propagation of canine distemper virus was strongly inhibited. Inhibitor MI‐1148 was crystallized in complex with human furin. Its N‐terminal guanidinomethyl group in the para position of the P5 phenyl ring occupies the same position as that found previously for a structurally related inhibitor containing this substitution in the meta position, thereby maintaining all of the important P5 interactions. Our results confirm that the inhibition of furin is a promising strategy for a short‐term treatment of acute infectious diseases. 相似文献
36.
Susanne Leuchs Dr. Lasse Greiner Dominique Dechambre Dr. Lasse Greiner Prof. André Bardow 《化学,工程师,技术》2012,84(4):427-431
The illustrated literature series Asterix (and Obelix) is commonly known as entertainment and distraction, but behind that mask, case studies for chemical production in small medium enterprises and the crucial role of research and development can be discovered. The series rightly puts chemistry and chemical engineering at the heart of success and prosperity. Overall, the motives exemplified are of high relevance today for chemical industry. 相似文献
37.
38.
Susanne Fagerlund Jonathan Massera Mikko Hupa Leena Hupa 《Journal of the European Ceramic Society》2012,32(11):2731-2738
In this work crystallization kinetics of bioactive glasses 1–98 and 13–93 are discussed. Within a certain temperature–time window these glasses can be hot worked into various products without interfering with crystallization. The crystallization was studied isothermally by heating glass plates at different temperatures for different times. Phases in the samples were studied through XRD and SEM analyses. The nucleation-like curves and crystallization characteristics were measured with DTA. The temperature of maximum nucleation was measured for glass 1–98 at 725 °C and for 13–93 at 700 °C. The activation energy of crystallization of both glasses was 280 kJ/mol. The Johnson–Mehl–Avrami exponent and the SEM micrographs of the samples suggested surface crystallization. The primary crystalline phase was wollastonite. The growth rate of the crystallized surface layer was 1 order of magnitude higher in the plates of 1–98 than in 13–93. The results can be utilized to optimize the parameters in hot-working of the glasses. 相似文献
39.
Dr. Vlastimil Jirasko Dr. Nils-Alexander Lakomek Dr. Susanne Penzel Dr. Marie-Laure Fogeron Prof. Dr. Ralf Bartenschlager Prof. Dr. Beat H. Meier Dr. Anja Böckmann 《Chembiochem : a European journal of chemical biology》2020,21(10):1453-1460
Proton-detected 100 kHz magic-angle-spinning (MAS) solid-state NMR is an emerging analysis method for proteins with only hundreds of microgram quantities, and thus allows structural investigation of eukaryotic membrane proteins. This is the case for the cell-free synthesized hepatitis C virus (HCV) nonstructural membrane protein 4B (NS4B). We demonstrate NS4B sample optimization using fast reconstitution schemes that enable lipid-environment screening directly by NMR. 2D spectra and relaxation properties guide the choice of the best sample preparation to record 2D 1H-detected 1H,15N and 3D 1H,13C,15N correlation experiments with linewidths and sensitivity suitable to initiate sequential assignments. Amino-acid-selectively labeled NS4B can be readily obtained using cell-free synthesis, opening the door to combinatorial labeling approaches which should enable structural studies. 相似文献
40.
Neil Gerard Quigley Dr. Stefano Tomassi Dr. Francesco Saverio di Leva Dr. Salvatore Di Maro Dr. Frauke Richter Dr. Katja Steiger Prof. Dr. Susanne Kossatz Prof. Dr. Luciana Marinelli Dr. Johannes Notni 《Chembiochem : a European journal of chemical biology》2020,21(19):2836-2843
αvβ6 Integrin is an epithelial transmembrane protein that recognizes latency-associated peptide (LAP) and primarily activates transforming growth factor beta (TGF-β). It is overexpressed in carcinomas (most notably, pancreatic) and other conditions associated with αvβ6 integrin-dependent TGF-β dysregulation, such as fibrosis. We have designed a trimeric Ga-68-labeled TRAP conjugate of the αvβ6-specific cyclic pentapeptide SDM17 (cyclo[RGD-Chg-E]-CONH2) to enhance αvβ6 integrin affinity as well as target-specific in-vivo uptake. Ga-68-TRAP(SDM17)3 showed a 28-fold higher αvβ6 affinity than the corresponding monomer Ga-68-NOTA-SDM17 (IC50 of 0.26 vs. 7.4 nM, respectively), a 13-fold higher IC50-based selectivity over the related integrin αvβ8 (factors of 662 vs. 49), and a threefold higher tumor uptake (2.1 vs. 0.66 %ID/g) in biodistribution experiments with H2009 tumor-bearing SCID mice. The remarkably high tumor/organ ratios (tumor-to-blood 11.2; -to-liver 8.7; -to-pancreas 29.7) enabled high-contrast tumor delineation in PET images. We conclude that Ga-68-TRAP(SDM17)3 holds promise for improved clinical PET diagnostics of carcinomas and fibrosis. 相似文献