全文获取类型
收费全文 | 114篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学 | 73篇 |
力学 | 9篇 |
数学 | 5篇 |
物理学 | 31篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 4篇 |
排序方式: 共有118条查询结果,搜索用时 15 毫秒
21.
22.
O.N. Ulenikov E.S. Bekhtereva T.D. Homiak T.R. Huet F. Herregodts W. Jerzembeck 《Journal of Molecular Spectroscopy》2003,222(2):153-158
The high resolution spectrum of a phosphine gas mixture containing PHD2 was recorded at room temperature in the 12 550-12 770 cm−1 region. A high sensitivity laser photoacoustic spectrometer consisting of a longitudinal resonant cell coupled to a Ti:sapphire ring laser was employed. More than 600 transitions were assigned to the 6ν1 overtone band of PHD2 up to Jmax=20, Kamax=6. A Hamiltonian model developed up to the octic centrifugal distortion terms was used. Seven rotational and centrifugal distortion parameters were fitted, the other ones being fixed to their values linearly extrapolated from ν1 and 2ν1. The derived parameters reproduce the initial data within the experimental uncertainties. The isolated character of the P-H bond is confirmed. 相似文献
23.
Epoxidation of 2, 3, 4 with m-CPBA mainly led to the cis-attack products whereas 1 and 6 led to the other selectivity. The result was reversed, from 4, with Payne's reagent. Bromohydroxylation of 4 involved an intermediate bromonium ion syn to the substituents. Haloselenylations occurred with the syn-selectivity from 1, 2, 3 and 4, to the anti-selectivity from 6, and without selectivity from 5. NOE enhancement measurements and several chemical correlations led to the stereochemical assignments. Formation of the intramolecular reaction products 24 and 25 was also pointed out. 相似文献
24.
25.
F.?Huet M.?MusianiEmail author R.?P.?Nogueira 《Journal of Solid State Electrochemistry》2004,8(10):786-793
Rough and porous Ni layers have been obtained by cathodic deposition from a NiCl2, NH4Cl solution, at high current density. Characterisation by SEM has shown that they consisted of micro-dendrites separated by pores with a typical diameter of 1 m. In addition, circular hollows (10–100 m in diameter) were found on the deposit surface; their density varied with the deposition current density and deposition charge. The surface roughness of the Ni deposits, measured by EIS, was found to increase roughly linearly with the deposition charge, and to be little dependent on current density, provided a threshold value was exceeded. The oxygen evolution reaction has been studied on these electrodes by simultaneous real-time measurements of potential and electrolyte resistance fluctuations. The analysis of the electrochemical noise indicated that the dimensions of oxygen bubbles detaching from the electrodes slightly increased with the deposit surface roughness. It is not clear, however, whether or not this increase was associated with the effect of the small (1 m) or the large (10–100 m) features on the electrode-bubble interactions. 相似文献
26.
Myoglobin CNBr peptides, constituting the commercially available molecular weight calibration kits for sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were analyzed by microsequencing after electroblotting on polyvinylidene difluoride (Immobilon) membranes. An obvious disagreement was found between peptide identification and the data provided by the manufacturers. We observed 6 peptides from Mr 2500 to 17,000 corresponding, in increasing size order, to the 3 peptides resulting from the total CNBr digestion, to 2 incompletely cleaved peptides and to the intact myoglobin. Using a corrected calibration curve, a linear relationship was established from Mr 6000 to 43,000 and a second one for shorter peptides. This method of electrophoresis and electroblotting, easily adapted for peptides, is a powerful tool for peptide identification correlated with size determination. It is especially useful for CNBr-cleaved peptides. 相似文献
27.
A rapid procedure, based on closed vessels microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS), was evaluated to ascertain the effect of chronic exposure to cadmium on intracellular accumulation of minor and essential trace elements in cultured epithelial cells (Caco-2 TC7). For all measurements, the method of external calibration was used and 3 elements (Be, Sc, In) were selected as internal standards. Optimization procedures are discussed and results are presented for the total determination of 9 key analytes (Na, Mg, Ca, Cr, Mn, Cu, Zn, Mo, and Cd) in certified reference materials (CRMs) and 20 samples of Caco-2 TC7 cells long-term exposed to Cd. The performance characteristics of the analytical system were evaluated by calibration and linearity, limits of detection and quantitation, accuracy with spiking, trueness and repeatability with available CRMs. As a complement to the ICP-MS determinations, both available CRMs and cell samples were analyzed either by electro thermal- or flame atomic absorption spectrometry. The results were in good agreement with the ICP-MS results. 相似文献
28.
Stéphane GuillarmeStéphanie Legoupy Nathalie BourgougnonAnne-Marie Aubertin François Huet 《Tetrahedron》2003,59(48):9635-9639
Acyclonucleosides 4 have been obtained by a short way starting from ethyl 2-hydroxymethyl acrylate 5. The key intermediate was acetate 9. Its reaction with free or protected nucleic bases gave either the expected compounds or unusual regioisomers. 相似文献
29.
I. Hadj Bachir T. R. Huet J. L. Destombes M. Vervloet 《Chemical physics letters》1997,270(5-6):533-537
A hollow cathode combined with a corona excited supersonic expansion has proven to be an efficient method of producing a stable discharge in a N2/Ar gas mixture. A high-resolution and rotationally cold absorption spectrum of the well-known (2,0) and (8,7) bands of the B3Πg ← A3Σu+ first positive system of N2 was recorded. It illustrates the sensitivity of the laser optogalvanic detection technique coupled to such an apparatus. A significant reduction of the linewidth and an enhancement of the signal-to-noise ratio were obtained. A high variational excitation process has been observed and is discussed. 相似文献
30.