全文获取类型
收费全文 | 712篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
化学 | 426篇 |
晶体学 | 8篇 |
力学 | 2篇 |
数学 | 94篇 |
物理学 | 197篇 |
出版年
2022年 | 6篇 |
2020年 | 15篇 |
2019年 | 9篇 |
2016年 | 14篇 |
2015年 | 19篇 |
2014年 | 16篇 |
2013年 | 34篇 |
2012年 | 26篇 |
2011年 | 34篇 |
2010年 | 21篇 |
2009年 | 27篇 |
2008年 | 22篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 26篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 18篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 13篇 |
1996年 | 18篇 |
1995年 | 13篇 |
1994年 | 19篇 |
1993年 | 12篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1973年 | 10篇 |
1972年 | 4篇 |
1970年 | 4篇 |
1958年 | 5篇 |
1896年 | 4篇 |
排序方式: 共有727条查询结果,搜索用时 15 毫秒
1.
Henry Dring David Kreutzer Christoph Ritter Andreas Hilgeroth 《Molecules (Basel, Switzerland)》2021,26(1)
Despite the development of targeted therapies in cancer, the problem of multidrug resistance (MDR) is still unsolved. Most patients with metastatic cancer die from MDR. Transmembrane efflux pumps as the main cause of MDR have been addressed by developed inhibitors, but early inhibitors of the most prominent and longest known efflux pump P-glycoprotein (P-gp) were disappointing. Those inhibitors have been used without knowledge about the expression of P-gp by the treated tumor. Therefore the use of inhibitors of transmembrane efflux pumps in clinical settings is reconsidered as a promising strategy in the case of the respective efflux pump expression. We discovered novel symmetric inhibitors of the symmetric efflux pump MRP4 encoded by the ABCC4 gene. MRP4 is involved in many kinds of cancer with resistance to anticancer drugs. All compounds showed better activities than the best known MRP4 inhibitor MK571 in an MRP4-overexpressing cell line assay, and the activities could be related to the various substitution patterns of aromatic residues within the symmetric molecular framework. One of the best compounds was demonstrated to overcome the MRP4-mediated resistance in the cell line model to restore the anticancer drug sensitivity as a proof of concept. 相似文献
2.
3.
von Eynatten G. Ritter T. Bömmel H. E. Dransfeld K. 《Zeitschrift für Physik B Condensed Matter》1987,65(3):341-345
A new model is presented which explains well the dramatic decrease of the Mössbauer line intensities with raising temperatures for freely dispersed iron microscrystals. In contrast to other theories which consider mainly vibration to be responsible we discuss here the decrease in terms of large amplitude diffusive rotational or translational jumps of the particles. Such diffusive jumps lead — in agreement with the observation — to a strong reduction of the Mössbauer-intensity without broadening the line width in a noticeable way. The typical potential well for a diffusing particle in an equilibrium position is derived quantitatively to be 13 meV. The model might be important also for a new understanding of the dynamics of catalytic clusters either in contact with each other or with larger solid surfaces.Part of this work was supported by the DFG Sonderforschungsbereich 306, Konstanz 相似文献
4.
Dedicated to the memory of John Oxtoby 相似文献
5.
M. Köhl A. Öttl S. Ritter T. Donner T. Bourdel T. Esslinger 《Applied physics. B, Lasers and optics》2007,86(3):391-393
We report an experimental investigation of two-particle correlations between neutral atoms in a Hanbury Brown and Twiss experiment.
Both an atom laser beam and a pseudo-thermal atomic beam are extracted from a Bose–Einstein condensate and the atom flux is
measured with a single atom counter. We determine the conditional and the unconditional detection probabilities for the atoms
in the beam and find good agreement with the theoretical predictions.
PACS 03.75.Pp; 05.30.Jp; 07.77.Gx; 42.50.Pq 相似文献
6.
We present a Bayesian theory of object identification. Here, identifying an object means selecting a particular observation from a group of observations (variants), this observation (the regular variant) being characterized by a distributional model. In this sense, object identification means assigning a given model to one of several observations. Often, it is the statistical model of the regular variant, only, that is known. We study an estimator which relies essentially on this model and not on the characteristics of the “irregular” variants. In particular, we investigate under what conditions this variant selector is optimal. It turns out that there is a close relationship with exchangeability and Markovian reversibility. We finally apply our theory to the case of irregular variants generated from the regular variant by a Gaussian linear model. 相似文献
7.
8.
Grosnick D Wright SC Bolton RD Cooper MD Frank JS Hallin AL Heusi PA Hoffman CM Hogan GE Mariam FG Matis HS Mischke RE Piilonen LE Sandberg VD Sanders GH Sennhauser U Werbeck R Williams RA Wilson SL Hofstadter R Hughes EB Ritter MW Highland VL McDonough J 《Physical review letters》1986,57(26):3241-3244
9.
10.
Mixtures of BCl3 and H2S are irradiated with 10.55 μm radiation (P(16) line of the 001–100 band of CO2) from a TEA laser. After several hours of irradiation it is found that the maximum 10B to 11B ratio of recovered gaseous boron containing material (primarily unreacted BCl3) is 0.413 ± 0.004. The corresponding ratio of the BCl3 starting material is 0.242 ± 0.002. The 10B concentration has therefore been increased from 19.5% to 29.2%. Further, by irradiating similar mixtures with 10.18 μm radiation (R(30) line of the same CO2 vibrational band) this ratio changes to 0.169 ± 0.002, the 10B concentration being lowered to 14.4%. All experiments are performed in a small static system and chemical procedures for recovering milligram quantities of BCl3 selectively enriched in either isotope are described. 相似文献