全文获取类型
收费全文 | 47篇 |
免费 | 1篇 |
专业分类
化学 | 28篇 |
物理学 | 17篇 |
无线电 | 3篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2004年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1891年 | 2篇 |
1890年 | 1篇 |
排序方式: 共有48条查询结果,搜索用时 8 毫秒
11.
F Debatin K Behrens J Weber IA Baburin A Thomas J Schmidt I Senkovska S Kaskel A Kelling N Hedin Z Bacsik S Leoni G Seifert C Jäger C Günter U Schilde A Friedrich HJ Holdt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(37):11630-11640
We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-1-4, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.0-1.7??), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and (1) H?MAS and (13) C?CP-MAS?NMR spectroscopy. All IFPs showed high thermal stability (345-400?°C); IFP-1 and IFP-4 were stable in boiling water for 7?d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO(2) was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH(4) (at 298?K), CO(2) (at 298?K) and H(2) (at 77?K) at high pressure were also investigated. In situ IR spectroscopy showed that CO(2) is physisorbed on IFP-1-4 under dry conditions and that both CO(2) and H(2) O are physisorbed on IFP-1 under moist conditions. 相似文献
12.
M. Blix und S. G. Hedin 《Fresenius' Journal of Analytical Chemistry》1891,30(1):652-654
Ohne Zusammenfassung 相似文献
13.
Analytical and Bioanalytical Chemistry - 相似文献
14.
An effective generation of reactive oxygen species (ROS) is of interest from the perspective of environmental technology and industrial chemistry, and here piezocatalysis and photocatalysis using heterostructures based on iodide-doped BiVO4/BaTiO3 with photodeposited Ag or Cu nanoparticles (BiVO4:I/BTO-Ag or BiVO4:I/BTO-Cu) is studied. The generation rates of •OH and •O2− radicals over BiVO4:I/BTO-Ag during piezophotocatalysis are 371 and 292 µmol g−1 h−1, respectively, and significantly higher than those of sole piezocatalysis and photocatalysis. These rates are among the highest reported for the production of free radicals with the piezophototronic effect. Among the catalysts, BiVO4:I/BTO shows the highest reactivity for the production of H2O2 in piezocatalysis (with a concentration of 468 µm after 100 min of irradiation, and still constantly increasing). On BiVO4:I/BTO-Ag and BiVO4:I/BTO-Cu, it seems that redundant electrons and holes had reacted effectively with the generated H2O2 and in turn had reduced their activities; however, the amounts of H2O2 that are formed on BiVO4:I/BTO-Ag or BiVO4:I/BTO-Cu under piezophotocatalysis are superior to those of individual piezocatalysis and photocatalysis. A piezophototronic coupling via an ultrasound-mediated and piezoelectric-based polarization field and photoexcitation accounting for the enhanced photocatalytic activity of the iodine-doped heterostructures with plasmonically sized Ag or Cu nanoparticles is suggested. 相似文献
15.
Lars Hedin 《International journal of quantum chemistry》1995,56(5):445-452
This article deals with excited-state properties and spectroscopies which probe them. We argue that the orbitals obtained in local density theory form an excellent basis for discussing excited states and that the self-energy operator (or optical potential) associated with one-electron-type excited states is closely diagonal in such a basis. This diagonality often leads to considerable simplifications. We also discuss the reasons for the successes of the “GW -approximation” for the optical potential in predicting excited states. We further discuss a recent approach to calculate spectroscopic data. In particular, we present explicit results of this approach to photoelectron emission. The approach treats correlations within the target exactly but neglects some terms in the coupling between target and probe electron (= the photoemitted electron). This leads to closed expressions which exhibit a number of qualitative features. One is the cancellation of intrinsic and extrinsic losses at threshold excitation. Another is the broadening of the quasi-particles; we have energy-broadening for the occupied states but broadening through decaying wave functions for unoccupied states. © 1995 John Wiley & Sons, Inc. 相似文献
16.
The phase cycling scheme Exorcycle embedded into the quadrupolar echo pulse sequence is presented as a tool for reducing ringing effects in broad quadrupolar spectra. 相似文献
17.
18.
Franziska Debatin Arne Thomas Prof. Dr. Alexandra Kelling Niklas Hedin Dr. Zoltan Bacsik Dr. Irena Senkovska Dr. Stefan Kaskel Prof. Dr. Matthias Junginger Holger Müller Uwe Schilde Prof. Dr. Christian Jäger Prof. Dr. Alwin Friedrich Dr. Hans‐Jürgen Holdt Prof. Dr. 《Angewandte Chemie (International ed. in English)》2010,49(7):1258-1262
19.
Hedin J Löfroth JE Nydén M 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):6148-6155
The adsorption behavior of ethyl(hydroxyethyl) cellulose EHEC and hydrophobically modified EHEC (HM-EHEC) at hydrophilic and hydrophobic surfaces has been studied using surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation monitoring (QCM-D) methods. The adsorbed amounts measured with the different methods were different due to large amounts of water in the films. The slow adsorption process made it reasonable to assume a continuous polymer reconfiguration process at the surface. This was mostly seen for HM-EHEC at the hydrophobic surface, where a more flexible structure was adopted during the adsorption process. A cross-linking agent was seen to truly interpolymer cross-link EHEC at the hydrophilic surface and HM-EHEC at the hydrophobic surface. For EHEC at a hydrophobic surface and for HM-EHEC at a hydrophilic surface, the polymers adsorbed in an individually phase-separated manner, making an interpolymer cross-linking reaction unsuccessful. 相似文献
20.
The COmponent-REsolved (CORE) strategy has been employed, for the first time to solid state NMR spectroscopy. CORE was used to extract two time-dependent spectral components in 24 29Si{1H} NMR spectra, recorded on a meso-structured silica material under conditions of cross polarization evolution. No prior assumptions were made about the component bandshapes, which were both found to be skewed to higher chemical shifts. For the silica fragments close to protons this skewness could be rationalized by a distribution of the degree of condensation in the silica network; however, for the other component the non-Gaussian shape was unexpected. We expect that the same strategy could be applied to a range of experiments in solid-state NMR spectroscopy, where spectral distributions or kinetic parameters need to be accurately extracted. 相似文献