全文获取类型
收费全文 | 726篇 |
免费 | 10篇 |
专业分类
化学 | 412篇 |
晶体学 | 7篇 |
力学 | 18篇 |
数学 | 64篇 |
物理学 | 235篇 |
出版年
2022年 | 6篇 |
2020年 | 9篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 16篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 15篇 |
2013年 | 55篇 |
2012年 | 31篇 |
2011年 | 27篇 |
2010年 | 35篇 |
2009年 | 25篇 |
2008年 | 20篇 |
2007年 | 28篇 |
2006年 | 30篇 |
2005年 | 23篇 |
2004年 | 22篇 |
2003年 | 13篇 |
2002年 | 18篇 |
2001年 | 17篇 |
2000年 | 15篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1991年 | 9篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 10篇 |
1974年 | 7篇 |
1973年 | 18篇 |
1972年 | 10篇 |
1971年 | 8篇 |
1969年 | 5篇 |
1968年 | 11篇 |
1967年 | 5篇 |
1966年 | 8篇 |
1958年 | 5篇 |
排序方式: 共有736条查询结果,搜索用时 0 毫秒
681.
This paper deals with the mathematical modelling of large strain magneto-viscoelastic deformations. Energy dissipation is assumed to occur both due to the mechanical viscoelastic effects as well as the resistance offered by the material to magnetisation. Existence of internal damping mechanisms in the body is considered by decomposing the deformation gradient and the magnetic induction into ‘elastic’ and ‘viscous’ parts. Constitutive laws for material behaviour and evolution equations for the non-equilibrium fields are derived that agree with the laws of thermodynamics. To illustrate the theory the problems of stress relaxation, magnetic field relaxation, time dependent magnetic induction and strain are formulated and solved for a specific form of the constitutive law. The results, that show the effect of several modelling parameters on the deformation and magnetisation process, are illustrated graphically. 相似文献
682.
CdS/PS and ZnS/PS nanocomposites have been prepared by solution casting method with different wt% of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles and characterized through X-ray diffraction and transmission electron microscope measurements. The effective thermal conductivity of polymer nanocomposites has been measured by transient plane source method over the temperature range from room to 150 °C. The experimental results showed that the thermal conductivity has been found to increase up to 4 wt% of CdS/ZnS nanoparticles and then decrease for 6 and 8 wt% of nanoparticles. 相似文献
683.
R. Dandoloff A. Saxena 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):265-267
For a spin-polarized electron gas on an elastic cylinder in an external axial magnetic field and an axial electric field we
find that the corresponding Euler-Lagrange equation is the double sine-Gordon (DSG) equation with an exact 2π-skyrmion solution.
The DSG skyrmion is stabilized, without Coulomb repulsion, by the curvature of the cylinder. It adopts a characteristic length
ξ which is smaller than the radius of the cylinder. For an elastic cylinder this mismatch of length scales causes a deformation
of the cylinder in the region of the skyrmion.
Received 23 October 2001 / Received in final form 8 March 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: rossen.dandoloff@ptm.u-cergy.fr 相似文献
684.
Glutamic acid can be titrated quantitatively against standard cadmium acetate using 4-(2-thiozolyl azo) resorcin as indicator in presence of boric acid-borax buffer at pH 9.0. Small concentrations of other natural amino acids do not interfere with the titration. However the presence of an equivalent molar concentration of histidine can cause an error of about 6%. 相似文献
685.
Saxena S. C. und J. P. Agrawal 《Colloid and polymer science》1962,184(1):67
Ohne Zusammenfassung 相似文献
686.
687.
688.
S. J. S. Lister F. M. Grosche F. V. Carter R. K. W. Haselwimmer S. S. Saxena N. D. Mathur S. R. Julian G. G. Lonzarich 《Zeitschrift für Physik B Condensed Matter》1996,103(2):263-265
We have explored the vicinity of the antiferromagnetic quantum critical point in the related heavy fermion metals CePd2Si2 and CeNi2Ge2 as a function of hydrostatic pressure. The normal state resistivity of the antiferromagnet CePd2Si2 near the critical pressure, at which magnetic order disappears, varies as ρ ~ Tχ(1:1 < χ < 1:4) over nearly two orders of magnitude in temperature up to about 30 K. This anomalous form for the resistivity appears to defy not only Fermi-liquid theory, but also simple phenomenological models for the effect of spin fluctuations close to a quantum critical point. An analogous unconventional behaviour is observed in the ambient pressure resistivity of the electronically and structurally equivalent, non-magnetic metal CeNi2Ge2. At pressures above 15 kbar, a new and unexpected superconducting transition appears in CeNi2Ge2 below 220 mK, which rises to higher temperatures with increasing pressure, reaching 400 mK at 26 kbar. 相似文献
689.
Using the zero mode method, we compute the conductance of a wire consisting of a magnetic impurity coupled to two Luttinger liquid leads characterized by the Luttinger exponent alpha(>or=1). We find for resonance conditions, in which the Fermi energy of the leads is close to a single particle energy of the impurity, that the conductance as a function of temperature is G approximately equal (e(2)/h)(T/T(F))(2(alpha-2)), whereas for off-resonance conditions the conductance is G approximately equal (e(2)/h)(T/T(F))(2(alpha-1)). By applying either a gate voltage or a magnetic field or both, one of the spin components can be in resonance while the other is off resonance causing a strong asymmetry between the spin-up and spin-down conductances. 相似文献
690.