全文获取类型
| 收费全文 | 117篇 |
| 免费 | 4篇 |
| 国内免费 | 1篇 |
专业分类
| 化学 | 88篇 |
| 晶体学 | 1篇 |
| 数学 | 26篇 |
| 物理学 | 7篇 |
出版年
| 2023年 | 1篇 |
| 2022年 | 6篇 |
| 2021年 | 7篇 |
| 2020年 | 3篇 |
| 2019年 | 3篇 |
| 2018年 | 3篇 |
| 2017年 | 4篇 |
| 2016年 | 4篇 |
| 2015年 | 3篇 |
| 2014年 | 9篇 |
| 2013年 | 10篇 |
| 2012年 | 7篇 |
| 2011年 | 2篇 |
| 2010年 | 5篇 |
| 2009年 | 8篇 |
| 2008年 | 7篇 |
| 2007年 | 4篇 |
| 2006年 | 2篇 |
| 2005年 | 3篇 |
| 2004年 | 4篇 |
| 2003年 | 3篇 |
| 2002年 | 4篇 |
| 2001年 | 1篇 |
| 2000年 | 2篇 |
| 1997年 | 2篇 |
| 1996年 | 1篇 |
| 1995年 | 1篇 |
| 1990年 | 2篇 |
| 1989年 | 1篇 |
| 1988年 | 1篇 |
| 1984年 | 1篇 |
| 1983年 | 2篇 |
| 1982年 | 2篇 |
| 1981年 | 1篇 |
| 1979年 | 2篇 |
| 1974年 | 1篇 |
排序方式： 共有122条查询结果，搜索用时 15 毫秒
21.
Bodi Dorina Ringling Christiane Sch&#;del Caroline Prei&#;-Weigert Angelika Fry Hildburg 《Chromatographia》2013,76(11):651-662
A comprehensive survey of matrix effects on the LC–MS/MS analysis of the banned antibiotic growth promoters carbadox and olaquindox in feed was carried out. Various factors of sample preparation procedure and measurement were systematically investigated by pre- and post-extraction addition and postcolumn infusion experiments. In general, strong signal suppression up to 70 % for carbadox and up to 90 % for olaquindox was observed when using different extraction solvents and techniques as well as different chromatographic conditions. Reduction of matrix effects was achieved by SPE clean-up and dilution of sample extracts. Nevertheless, matrix effect profiles determined by postcolumn infusion revealed, that reduction of signal suppression at a respective retention time cannot guarantee improvement of the methods performance. If high variability of matrix effects is present along the chromatographic run, accuracy might decrease despite reduced signal suppression. Besides method parameters, different feedingstuffs were investigated and showed similar matrix effects.
相似文献22.
A new route for adding self‐healing properties to soluble polymers is presented briefly. Self‐healing block copolymers (polystyrene‐block‐polybutadiene block‐polystyrene from Sigma‐Aldrich) were obtained by dissolving the polymer in a solvent that neither dissolves the microbubbles nor deactivate the Grubbs catalyst. The self‐healing block copolymer has been obtained by mixing the polymer, the solvent, the microbubbles filled with monomer (dicyclopentadiene), and the Grubbs' catalyst followed by the evaporation of the solvent. The structure of self‐healed high elasticity block copolymer has been investigated by optical and Scanning Electron Microscopy. Raman spectroscopy and mechanical data suggested that the block copolymer exhibits self‐healing features. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
23.
Mazzeo P Di Pasquale D Ruggieri F Fanelli M D'Archivio AA Carlucci G 《Biomedical chromatography : BMC》2007,21(11):1166-1171
A high-performance liquid chromatographic method for the simultaneous determination of di(2-ethylhexyl)phthalate (DEHP) and its major metabolite mono(2-ethylhexyl)phthalate (MEHP) in seminal plasma was developed and validated. The method involves liquid-liquid extraction followed by isocratic reversed-phase chromatography with diode-array detection. The recovery, selectivity, linearity, precision and accuracy of the method were evaluated from the analysis of spiked seminal plasma samples. The effect of mobile-phase composition and pH on the retention of the target analytes was investigated. The limits of detection were 0.010 and 0.015 microg/mL, for DEHP and MEHP, respectively. This method was used to analyze real samples in support of clinical studies on these potential endocrine disruptors. 相似文献
24.
Mihai Draghici Dorina Diaconescu Alexander Melnikov Andreas D. Wieck 《physica status solidi (a)》2010,207(1):229-234
In‐plane gate (IPG) transistors with various channel geometries have been fabricated by focus ion beam implantation technique in positive pattern definition mode on GaAs/AlxGa1−xAs heterostructures. Both n‐ and p‐type channel transistors were obtained for either n‐ or p‐doped heterostructures, by implantation of the channel or the gate regions with the complementary dopant type to compensate the initial doping. The current–voltage characteristics showed that the channel can be fully controlled by a gate bias, i.e., it can be completely depleted or enhanced, but two gates are needed to control the channel. Different channel geometries were studied, the most efficient being the “Z‐shaped” one. The n‐type channel IPG transistors present source–drain currents of few hundreds of microamperes, which is two to three orders of magnitudes higher than that for the p‐type channel ones. 相似文献
25.
Dorina Mitrea 《Transactions of the American Mathematical Society》2008,360(7):3771-3793
Let be the solution operator for in , Tr on , where is a bounded domain in . B. E. J. Dahlberg proved that for a bounded Lipschitz domain maps boundedly into weak- and that there exists such that is bounded for . In this paper, we generalize this result by addressing two aspects. First we are also able to treat the solution operator corresponding to Neumann boundary conditions and, second, we prove mapping properties for these operators acting on Sobolev (rather than Lebesgue) spaces.
26.
Elena Perju Simon J. Dünki Dorina M. Opris 《Journal of polymer science. Part A, Polymer chemistry》2016,54(18):2940-2948
A synthetic strategy to polydimethylsiloxanes and polymethylsiloxanes containing thiol functions as end‐ or side‐groups, respectively, is presented. Such polymers are important starting materials for elastomeric networks and postpolymerization modifications. The synthesis starts either with vinyl end‐functionalized polydimethylsiloxanes or with polymethylvinylsiloxanes. The vinyl groups are reacted either with thioacetic acid or with a thioacetic acid/butanethiol mixture via a UV‐initiated thiol‐ene reaction to form the respective thioester quantitatively within few minutes. The thioesters are subsequently deprotected to the respective thiols by reduction with LiAlH4. The resulting thiol containing polysiloxanes can be used for the formation of networks or another functionalization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2940–2948 相似文献
27.
Mircea Chipara John R. Villarreal Magdalena Dorina Chipara Karen Lozano Alin Cristian Chipara David J. Sellmyer 《Journal of Polymer Science.Polymer Physics》2009,47(17):1644-1652
Isotactic polypropylene‐vapor grown carbon nanofiber composites containing various fractions of carbon nanofibers, ranging from 0 to 20 wt %, have been prepared. Raman spectroscopy was used to analyze the effect of the dispersion of carbon nanofibers within polypropylene and the interactions between carbon nanofibers and macromolecular chains. The as‐recorded Raman spectra have been successfully fitted by a linear convolution of Lorentzian lines. Changes of the Raman lines parameters (position, intensity, width, and area) of polypropylene and carbon nanofibers were analyzed in detail. The Raman spectra of the polymeric matrix—at low concentrations of nanofibers—show important modifications that indicate strong interactions between carbon nanofibers and the polymeric matrix reflecting by vibrational dephasing of macromolecular chains. The Raman spectrum of carbon nanofibers is sensitive to the loading with carbon nanofibers, showing changes of the resonance frequencies, amplitudes, and width for both D‐ and G‐bands. Raman data reveals the increase of the disorder, as the concentration of carbon nanofibers is increased. The presence of the typical ESR line assigned to conducting electrons delocalized over carbon nanofibers is confirmed and the presence of a spurious magnetic line due to catalyst's residues is reported. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1644–1652, 2009 相似文献
28.
We study the Besov regularity of conformal mappings for domains with rough boundary based on the well-posedness for the Dirichlet problem with Besov data. Also, sharp invertibility results for the classical layer potential operators on Sobolev-Besov spaces on the boundary of curvilinear polygons are obtained. 相似文献
29.
Dorina Mitrea Heather Rosenblatt 《Mathematical Methods in the Applied Sciences》2006,29(12):1349-1361
We prove a rather general mean‐value formula in the theory of elasticity, which expresses the value of the displacement at the centre of a sphere in terms of certain combinations of integral averages over the sphere itself of the traction and the displacement. We also establish the corresponding converse to this mean‐value formula under minimal smoothness assumptions on the displacement. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
30.