全文获取类型
收费全文 | 353篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 199篇 |
晶体学 | 2篇 |
力学 | 21篇 |
数学 | 40篇 |
物理学 | 92篇 |
出版年
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 18篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 14篇 |
2009年 | 11篇 |
2008年 | 17篇 |
2007年 | 19篇 |
2006年 | 22篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 15篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有354条查询结果,搜索用时 15 毫秒
81.
T. Yu. Samgina V.A. Gorshkov K.A. Artemenko S.V. Kovalev S.V. Ogourtsov R. A Zubarev A.T. Lebedev 《Rapid communications in mass spectrometry : RCM》2010,24(12):1749-1754
Hyla arborea schelkownikowi is one of the leaf frog species inhabiting the southern territories of Russia and the former USSR. This frog species is a member of the Hylidae Rafinesque, 1815 batrachians family. The present study deals with the previously uninvestigated peptidome of the Hyla arborea schelkownikowi skin secretion. Nano‐electrospray ionization Fourier transform mass spectrometry (nanoESI‐FTMS) of the skin secretion, in the intact form and after acetylation, was selected as the general method of analysis. Electron‐capture dissociation (ECD) and collision‐induced dissociation (CID) fragmentation were both employed, while de novo sequencing was performed by manual interpretation of the MS data. The suppression of the cyclization of b‐ions in the mass spectrometer by the acetylation reaction proved to be very efficient for the de novo sequencing of short peptides. Ten skin peptides were found and all of them, except for bradykinin, had not previously been reported. Six of the peptides belong to the tryptophyllins and related peptides, while three peptides are similar to the aureins. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
82.
83.
JETP Letters - Unsteady plane potential flows of an ideal incompressible fluid with a free surface in the absence of external forces and capillarity are studied. An algorithm to construct exact... 相似文献
84.
Experiments with highly concentrated suspensions and other complex liquids frequently demonstrate nonmonotonic N- or S-shaped dependences of viscous stress σ on shear rate $
\dot \gamma
$
\dot \gamma
and strong oscillations of the shear rate at a constant flow-inducing external stress, as well as oscillations of the viscous
stress at a constant average shear rate. A phenomenological mathematical model is proposed for oscillating flows according
to which oscillations arise when an applied stress (or the average shear rate, depending on the design of an experiment) is
in the descending region of the σ-$
\dot \gamma
$
\dot \gamma
dependence and a complex liquid exhibits pronounced viscoelastic properties. 相似文献
85.
A reaction of methyllithium with 3-cyano-6-methylpyridine-2(1 H)-thione followed by alkylation of the resulting 3-acetylpyridinethione, or a direct reaction of methyllithium with 3-cyano-6-methyl-2-(methylthio)pyridine,
afforded 3-acetyl-6-methyl-2-(methylthio)pyridine. The ketone obtained was examined in bromination reactions under various
conditions. Bromi-nation in methanol or chloroform, proceeding through the formation of sulfonium bromides, gave substituted
3-(bromoacetyl)pyridine. A reaction of 3-acetyl-6-methyl-2-(methyl-thio)pyridine with N-bromosuccinimide in CCl4 afforded N-(pyridinesulfenyl)succinimide. The bromo ketone was used for the synthesis of various heterocyclic compounds. 相似文献
86.
[reaction: see text] We describe a synthesis of a dendrimer-like amphiphile containing a flat rigid core and 12 hydrophobic and hydrophilic arms. We employ a modular approach based on stepwise protection chemistry starting from simple building blocks. The key feature of this approach is the absence of a polymerization step, which makes it applicable for linear monofunctionalized precursors of any kind. This strategy also allows for precise control of the number of arms and ensures their alternating arrangement. 相似文献
87.
88.
89.
M. A. Gashkov N. M. Zubarev O. V. Zubareva G. A. Mesyats I. V. Uimanov 《Journal of Experimental and Theoretical Physics》2016,122(4):776-786
The formation of microjets is studied during the extrusion of a melted metal by the plasma pressure from craters formed on a cathode in a burning vacuum arc. An analytic model of liquid-metal splashing that includes two stages is proposed. At the first stage, the liquid motion has the axial symmetry and a liquid-metal wall surrounding the crater is formed. At the second stage, the axial symmetry is broken due to the development of the Plateau–Rayleigh instability in the upper part of the wall. The wall breakup process is shown to have a threshold. The minimal plasma pressure and the minimal electric current flowing through the crater required for obtaining the liquid-metal splashing regime are found. The basic spatial and temporal characteristics of the jet formation process are found using the analytic model. 相似文献
90.
Budnik BA Tsybin YO Håkansson P Zubarev RA 《Journal of mass spectrometry : JMS》2002,37(11):1141-1144
Ionization energies (IE) of [M + zH](z+) (z+) electrospray-produced polypeptides were determined by electron ionization in a Penning cell of 4.7 and 9.4 T Fourier transform mass spectrometers. For z = 1+ and substance P, the found IE value of 11.0 +/- 0.4 eV is in agreement with that obtained earlier for ions generated with matrix-assisted laser desorption/ionization. For higher z, the following values were found: 11.7 +/- 0.3 eV for 2+ of [Arg-8]-vasopressin, 11.1 +/- 0.6 eV for 2+ of substance P, 12.2 +/- 0.7 eV for 2+ of renin substrate, 13.3 +/- 0.4 eV for 3+ of B-chain of insulin and 14.6 +/- 0.6 eV for 4+ and 15.1 +/- 0.4 eV for 5+ of melittin. It was found that 90% of existing IE data on polypeptides in the 1.0-3.5 kDa mass range are described with 相似文献