全文获取类型
收费全文 | 199篇 |
免费 | 1篇 |
专业分类
化学 | 81篇 |
晶体学 | 2篇 |
力学 | 16篇 |
数学 | 22篇 |
物理学 | 79篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1932年 | 2篇 |
1908年 | 2篇 |
1902年 | 2篇 |
排序方式: 共有200条查询结果,搜索用时 15 毫秒
51.
F. Candau C. Dufour J. François H. Levy E. Marchal Y. Layec C. Wolff 《European Polymer Journal》1980,16(5):447-449
On the basis of the molecular weight dependence of dipole moment, critical frequency and apparent specific volume, it is shown that the behaviour of helical PBLG, when polymerized with triethylamine, is different from that observed for PBLG polymerized in dioxane with sodium methoxide. 相似文献
52.
Large-amplitude non-linear vibrations of micro- and nano-electromechanical resonant sensors around their primary resonance are investigated. A comprehensive multiphysics model based on the Galerkin decomposition method coupled with the averaging method is developed in the case of electrostatically actuated clamped-clamped resonators. The model is purely analytical and includes the main sources of non-linearities as well as fringing field effects. The influence of the higher modes and the validation of the model is demonstrated with respect to the shooting method as well as the harmonic balance coupled with the asymptotic numerical method. This model allows designers to investigate the sensitivity variation of resonant sensors in the non-linear regime with respect to the electrostatic forcing. 相似文献
53.
54.
55.
Dr. Jeremy Dufour Dr. Luc Neuville Dr. Jieping Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(34):10523-10534
Development of the total syntheses of arylomycins A1 and B2 is detailed. Key features of our approach include 1) formation of 14‐membered meta,meta‐cyclophane by an intramolecular Suzuki–Miyaura reaction; 2) incorporation of N‐Me‐4‐hydroxyphenylglycine into the cyclization precursor, which avoids the late‐stage low‐yielding N‐methylation step; 3) segment coupling of a fully elaborated peptide side chain to the macrocycle, which makes the synthesis highly convergent. Overall, arylomycin A2 was obtained in 13 steps from L ‐Tyr for the longest linear sequence, in 13 % overall yield. Arylomycin B2 was synthesized in 10 steps from L ‐3‐nitro‐Tyr, in 10 % overall yield. 相似文献
56.
H. Razafindralambo S. Dufour M. Paquot M. Deleu 《Journal of Thermal Analysis and Calorimetry》2009,95(3):817-821
Isothermal titration calorimetry was applied for studying the binding interactions of cyclic and linear surfactins with different
ionic charge (z= −2 and −3) and lipid chain length (n=14 and 18) to 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidyl-choline (POPC) vesicles in 10mMTris buffer at pH8.5with 150mMNaCl at 25°C. Surfactin analogues interacted
spontaneously (ΔG
D
w→b < 0) with POPC vesicles. The binding reactions were endothermic (ΔH
D
w→b > 0) and entropy-driven process (ΔS
D
w→b > 0). Moreover, significant differences in the binding constant values (K) ranging from 6.6·103 to 9.6·104 M−1 show that cyclic structure and the increase of lipid chain length are favourable on the surfactin binding affinity to POPC
vesicles, whereas the rise of the number of negative charges has an opposite effect. 相似文献
57.
Dufour DG Drummond JR McElroy CT Midwinter C Bernath PF Walker KA Nowlan C 《The journal of physical chemistry. A》2006,110(45):12414-12418
Laboratory measurements of NO(2) absorption were obtained in the visible (400-700 nm) and mid-infrared (3.4 mum) regions simultaneously using SCISAT-1's ACE-FTS (atmospheric chemistry experiment-Fourier transform spectrometer) and MAESTRO (measurement of aerosol extinction in the stratosphere and troposphere retrieved by occultation) spectrometers. An intercomparison of these measurements was used to verify the consistency between the HITRAN 2004 3.4-mum band strengths and the strengths of three different visible cross section data sets. These measurements should be of interest to the remote-sensing community, since NO(2) measurements obtained by infrared-range instruments are often compared to those obtained by visible-range instruments without accurate knowledge of the consistency between the visible and infrared absorption coefficients. Two significant results were obtained in this study: (1) A 0.5% agreement was found between the HITRAN 2004 line strengths and the Vandaele et al. (Vandaele, A. C.; Hermans, C.; Fally, S.; Carleer, M.; Colin, R.; Mérienne, M.-F.; Jenouvrier, A.; Coquart, B. J. Geophys. Res. 2002, 107 (D18), 4348) temperature-corrected cross sections, and (2) the mean pressure-broadened half-width of NO(2) by NO in the 3.4-mum band was measured as being 0.096 +/- 0.001 cm(-1) atm(-1). The latter finding is thought to be unreported by the literature. 相似文献
58.
Common components and specific weights analysis: a tool for monitoring the molecular structure of semi-hard cheese throughout ripening 总被引:1,自引:0,他引:1
Twelve semi-hard (Raclette) cheeses, belonging to four brand products, namely A (n = 3), B (n = 3), C (n = 3) and D (n = 3), were produced during summer period and ripened at an industrial scale. Tryptophan, riboflavin and vitamin A fluorescence spectra were scanned on the 12 cheeses at 2, 30 and 60 days of ripening. The physico-chemical analyses were performed only at the end of the ripening stage (60 days). Common components and specific weights analysis (CCSWA) were applied on the four data tables. CCSWA showed that the common component 1 (q1), discriminating cheeses labelled A, B and C from those labelled D, expressed 94.4 and 59% of the inertia of vitamin A and tryptophan fluorescence spectra and a less amount for riboflavin fluorescence spectra and physico-chemical data (24.2 and 13.2%, respectively). Common component 3 (q3), differentiating between cheeses labelled B and those labelled A and C, explained 34.6 and 23.9% of the inertia of the physico-chemical data and tryptophan fluorescence spectra, respectively, and a tiny part of the inertia of riboflavin and vitamin A fluorescence spectra (3.2 and 0.7%, respectively). The CCSWA showed its ability to describe the overall information collected from fluorescence and physico-chemical data tables and to extract relevant information at the molecular level throughout ripening of the investigated semi-hard cheeses. 相似文献
59.
Gas chromatography-olfactometry 总被引:2,自引:0,他引:2
GC-olfactometry (GC-O) refers to the use of human assessors as a sensitive and selective detector for odour-active compounds. The aim of this technique is to determine the odour activity of volatile compounds in a sample extract, and assign a relative importance to each compound. Methods can be classified into three types: detection frequency, dilution to threshold and direct intensity. Dilution to threshold methods measure the potency of odour-active compounds by using a series of extract dilutions, whereas detection frequency and direct-intensity methods measure odour-active compound intensity, or relative importance, in a single concentrated extract. Factors that should be considered to improve the value of GC-O analysis are the extraction method, GC instrument conditions, including the design and operation of the odour port, methods of recording GC-O data and controlling the potential for human assessor bias using experimental design and a trained panel. Considerable emphasis is placed on the requirement for multidimensional GC analysis, and on best practice when using human assessors. 相似文献
60.
Marianne Dufour Mateo Valdes Rimantas Lazauskas Paul-Antoine Hervieux 《Hyperfine Interactions》2018,239(1):41
The charge exchange reaction \(\bar {\mathrm {p}} + \text {Ps} \rightarrow \mathrm {e}^{-} + \bar {\mathrm {H}} \), of interest for the future experiments (GBAR, AEGIS, ATRAP, ...) aiming to produce antihydrogen atoms, is investigated in the energy range between the \(\mathrm {e}^{-}+\bar {\mathrm {H}}(n = 2)\) and \(\mathrm {e}^{-}+\bar {\mathrm {H}}(n = 3)\) thresholds. An ab-initio method based on the solution of the Faddeev-Merkuriev equations is used. Special focus is put on the impact of the Feshbach resonances and the Gailitis-Damburg oscillations, appearing in the vicinity of the \(\bar {\mathrm {p}} +\text {Ps}(n = 2)\) threshold, on the \(\bar {\mathrm {H}}\) production cross section. 相似文献