全文获取类型
收费全文 | 680篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
化学 | 500篇 |
晶体学 | 3篇 |
力学 | 6篇 |
数学 | 22篇 |
物理学 | 157篇 |
出版年
2022年 | 6篇 |
2021年 | 9篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2013年 | 17篇 |
2012年 | 13篇 |
2011年 | 19篇 |
2010年 | 12篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 28篇 |
2006年 | 23篇 |
2005年 | 20篇 |
2004年 | 27篇 |
2003年 | 16篇 |
2002年 | 30篇 |
2001年 | 25篇 |
2000年 | 18篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 21篇 |
1995年 | 14篇 |
1994年 | 16篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1990年 | 11篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 15篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 17篇 |
1980年 | 19篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1975年 | 7篇 |
1974年 | 6篇 |
1973年 | 8篇 |
1972年 | 8篇 |
1971年 | 9篇 |
1970年 | 6篇 |
1968年 | 7篇 |
1961年 | 6篇 |
1959年 | 4篇 |
1933年 | 4篇 |
排序方式: 共有688条查询结果,搜索用时 15 毫秒
1.
Ahmed Waqar Chowdhury Z. Z. Kazi S. N. Johan MR. Akram Naveed Oon C. S. Abdelrazek Ali H. 《Journal of Thermal Analysis and Calorimetry》2021,144(4):1517-1534
Journal of Thermal Analysis and Calorimetry - In recent decades, the growth of heat transfer using nanomaterials in the conventional base fluid has caught the attention of researchers... 相似文献
2.
This article introduces and analyzes a p-version FEM for variational inequalities resulting from obstacle problems for some quasi-linear elliptic partial differential
operators. We approximate the solution by controlling the obstacle condition in images of the Gauss–Lobatto points. We show
existence and uniqueness for the discrete solution u
p
from the p-version for the obstacle problem. We prove the convergence of u
p
towards the solution with respect to the energy norm, and assuming some additional regularity for the solution we derive
an a priori error estimate. In numerical experiments the p-version turns out to be superior to the h-version concerning the convergence rate and the number of unknowns needed to achieve a certain exactness of the approximation. 相似文献
3.
In quasi-steady operation, convection currents in a Bridgmandevice, used for producing a semi-conductor crystal, createinhomogeneities that may make the crystal unusable. It has oftenbeen suggested that additional forces due to rotation or magnetismmight be efficacious in reducing the segregation of the elementsof the alloy. It has been found that, over a wide range of rotationrates, there is no improvement in performance due to rotationabout the vertical axis. However, numerical results that havebeen obtained previously (Lee & Pearlstein, J. Crys. Growth240, 2002) indicate that, when effects of centrifugal buoyancyare introduced, a substantial reduction in segregation is achieved.In the work reported here, by contrast, in which we extend previouslarge-Rayleigh-number asymptotic analysis to include centrifugalbuoyancy, we find no improvement in radial segregation, butrather increasing segregation with increasing rotation rate. 相似文献
4.
5.
6.
7.
Synthesis and Structures of γ-Halopropyl-octa(silasesquioxanes) As a more rapid and versatile synthetic approach, we have studied the FeCl3-catalyzed hydrolytic polycondensation of suited trichlorosilanes in a biphasic system which yields e.g. the new octa(silasesquioxane) (BrCH2CH2CH2)8Si8O12. 相似文献
8.
9.
10.
V. V. Ammosov A. G. Denisov G. S. Gapienko V. A. Gapienko V. I. Klyukhin V. I. Koreshev P. V. Pitukhin V. I. Sirotenko Z. U. Usubov V. G. Zaetz A. E. Asratyan A. V. Fedotov P. A. Goritchev S. P. Krutchinin M. A. Kubantsev I. V. Makhlueva V. I. Shekelyan V. G. Shevchenko A. B. Krebs 《Zeitschrift fur Physik C Particles and Fields》1987,36(3):377-381
The cross section of the quasi-elastic reactions \(\bar v_\mu p \to \mu ^ + \Lambda (\Sigma ^0 )\) in the energy range 5–100 GeV is determined from Fermilab 15′ bubble chamber antineutrino data. TheQ 2 analysis of quasi-elastic Λ events yieldsM A=1.0±0.3 GeV/c2 for the axial mass value. With zero µΛ K 0 events observed, the 90% confidence level upper limit \(\sigma (\bar v_\mu p \to \mu ^ + \Lambda {\rm K}^0 )< 2.0 \cdot 10^{ - 40} cm^2 \) is obtained. At the same time, we found that the cross section of reaction \(\bar v_\mu p \to \mu ^ + \Lambda {\rm K}^0 + m\pi ^0 \) is equal to \(\left( {3.9\begin{array}{*{20}c} { + 1.6} \\ { - 1.3} \\ \end{array} } \right) \cdot 10^{ - 40} cm^2 \) . 相似文献