全文获取类型
收费全文 | 159篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
化学 | 90篇 |
数学 | 44篇 |
物理学 | 32篇 |
出版年
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 2篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1954年 | 1篇 |
1939年 | 1篇 |
1937年 | 1篇 |
1936年 | 1篇 |
1915年 | 1篇 |
1903年 | 1篇 |
1898年 | 1篇 |
排序方式: 共有166条查询结果,搜索用时 15 毫秒
1.
Daniel Loof Oliver Thüringer Dr. Marco Schowalter Dr. Christoph Mahr Anmona Shabnam Pranti Prof. Dr. Walter Lang Prof. Dr. Andreas Rosenauer Dr. Volkmar Zielasek Dr. Sebastian Kunz Prof. Dr. Marcus Bäumer 《ChemistryOpen》2021,10(7):697-712
Porous networks of Pt nanoparticles interlinked by bifunctional organic ligands have shown high potential as catalysts in micro-machined hydrogen gas sensors. By varying the ligand among p-phenylenediamine, benzidine, 4,4‘‘-diamino-p-terphenyl, 1,5-diaminonaphthalene, and trans-1,4-diaminocyclohexane, new variants of such networks were synthesized. Inter-particle distances within the networks, determined via transmission electron microscopy tomography, varied from 0.8 to 1.4 nm in accordance with the nominal length of the respective ligand. While stable structures with intact and coordinatively bonded diamines were formed with all ligands, aromatic diamines showed superior thermal stability. The networks exhibited mesoporous structures depending on ligand and synthesis strategy and performed well as catalysts in hydrogen gas microsensors. They demonstrate the possibility of deliberately tuning micro- and mesoporosity and thereby transport properties and steric demands by choice of the right ligand also for other applications in heterogeneous catalysis. 相似文献
2.
Lusine Sargsyan Thomas Hippe Hartmut Manneck Volkmar Vill 《Molecules (Basel, Switzerland)》2021,26(4)
The aim of this work was to optimize our natural hair dyeing system which we described in our previous work and to compare with other dyeing systems. Therefore, we investigated concentration limits of matcha and mordant and compared this new dyeing method with commercial permanent systems on the market. Completely unpigmented hair tresses were dyed with matcha powder (camelia sinensis) and iron(II)-lactate. To investigate the wash fastness and concentration limits, the differently dyed hair tresses were spectrophotometrically measured. The comparison of the damage potential for which cysteic acid is an indicator was measured by NIR. The concentration of matcha and mordant are responsible for the intensity of the color results. The higher the matcha or the mordant concentration, the darker the color results of the dyed hair tresses. Hair damage of matcha mordant dyeing is comparable with results of commercial permanent hair coloration systems. Moreover, the results of wash fastness of matcha mordant dyed hair tresses is comparable and even better by tendency to permanent colored hair tresses. 相似文献
3.
4.
5.
6.
Theo Scholtes Stefan Woetzel Rob IJsselsteijn Volkmar Schultze Hans-Georg Meyer 《Applied physics. B, Lasers and optics》2014,117(1):211-218
The intrinsic relaxation rates of the vector magnetization of cesium vapor enclosed in microfabricated atomic magnetometer cells are investigated. Two methods—the optically detected magnetic resonance and the ground-state Hanle effect—are used to carry out automated measurements in dependence on cell temperature and nitrogen buffer gas pressure. The experimental results are compared with expected contributions of the different relaxation processes and in this way allow the discrimination between them to help further optimization of cell design. The methods are compared in terms of basic features, data quality, and practical applicability. 相似文献
7.
8.
Andreas Petri Oliver SeidelmannUwe Eilitz Frank LeßmannStefan Reißmann Volkmar WendischAndrey Gutnov 《Tetrahedron letters》2014
Asymmetric conjugate addition of arylboronic acids to 2-nitroacrylamide in the presence of cationic palladium–Chiraphos complex proceeds with high yield and enantioselectivity (73–89% ee) using as low as 0.05–0.25 mol % of the catalyst. The adducts can be smoothly transformed into the corresponding β2-homophenylglycines in two simple steps. 相似文献
9.
10.