全文获取类型
收费全文 | 1602篇 |
免费 | 42篇 |
国内免费 | 12篇 |
专业分类
化学 | 1217篇 |
晶体学 | 14篇 |
力学 | 12篇 |
数学 | 104篇 |
物理学 | 309篇 |
出版年
2022年 | 13篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 22篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 27篇 |
2015年 | 14篇 |
2014年 | 49篇 |
2013年 | 85篇 |
2012年 | 92篇 |
2011年 | 116篇 |
2010年 | 45篇 |
2009年 | 63篇 |
2008年 | 103篇 |
2007年 | 92篇 |
2006年 | 104篇 |
2005年 | 103篇 |
2004年 | 80篇 |
2003年 | 89篇 |
2002年 | 76篇 |
2001年 | 25篇 |
2000年 | 38篇 |
1999年 | 17篇 |
1998年 | 23篇 |
1997年 | 16篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1974年 | 9篇 |
1973年 | 9篇 |
1972年 | 11篇 |
排序方式: 共有1656条查询结果,搜索用时 15 毫秒
171.
Kosuke Ono 《Journal of Mathematical Analysis and Applications》2005,310(2):347-361
Consider the Cauchy problem in odd dimensions for the dissipative wave equation: (□+∂t)u=0 in with (u,∂tu)|t=0=(u0,u1). Because the L2 estimates and the L∞ estimates of the solution u(t) are well known, in this paper we pay attention to the Lp estimates with 1p<2 (in particular, p=1) of the solution u(t) for t0. In order to derive Lp estimates we first give the representation formulas of the solution u(t)=∂tS(t)u0+S(t)(u0+u1) and then we directly estimate the exact solution S(t)g and its derivative ∂tS(t)g of the dissipative wave equation with the initial data (u0,u1)=(0,g). In particular, when p=1 and n1, we get the L1 estimate: u(t)L1Ce−t/4(u0Wn,1+u1Wn−1,1)+C(u0L1+u1L1) for t0. 相似文献
172.
K. Ono 《Geometric And Functional Analysis》2006,16(5):981-1020
We study Floer–Novikov cohomology with local coefficients and prove the flux conjecture for general closed symplectic manifolds.
Received: February 2005, Revised: May 2006, Accepted: May 2006
Partially supported by the Grant-in-Aid for Scientific Research No. 14003419, Japan Society for the Promotion of Sciences. 相似文献
173.
Akira Ono 《Physica C: Superconductivity and its Applications》1992,200(3-4):296-300
The compounds Ba1.4Sr0.6YCu3Oz (7.0≤z<7.4) were synthesized at 2 GPa to clarify the effect of high temperature and pressure on the superconducting properties. The structure as observed by powder X-ray diffraction was tetragonal for z≥7.2, and orthorhombic or tetragonal for z<7.1. It has been revealed that high-pressure syntheses suppress the superconductivity in the compounds with z<7.1. Recovery of the superconducting properties occurs above z≥7.2. The effect of Sr substitution on the superconducting properties was also studied. The magnitude of diamagnetism at 5–30 K decreases monotonically from −0.003 to −0.0002 emu/g Oe with increasing x in Ba2−xSrxYCu3Oz (x≥1.2). 相似文献
174.
In this paper, we present an efficient implementation of theO(mn + n
2 logn) time algorithm originally proposed by Nagamochi and Ibaraki (1992) for computing the minimum capacity cut of an undirected network. To enhance computation, various ideas are added so that it can contract as many edges as possible in each iteration. To evaluate the performance of the resulting implementation, we conducted extensive computational experiments, and compared the results with that of Padberg and Rinaldi's algorithm (1990), which is currently known as one of the practically fastest programs for this problem. The results indicate that our program is considerably faster than Padberg and Rinaldi's program, and its running time is not significantly affected by the types of the networks being solved.Corresponding author. 相似文献
175.
Ramachandran Saravanan Yasuhiro Ono Kahoru Ohno 《Journal of Physics and Chemistry of Solids》2003,64(1):51-58
Electron density distribution of GaAs is determined by means of the maximum entropy method (MEM) using reasonably good X-ray data collected at room temperature and 200 K. The bonding electron distributions are clearly visible in the MEM map and the mixed covalent-ionic character in GaAs is evidenced. The density distributions at 200 K show more condensed electronic clouds as compared to the room temperature map, preserving the trend in the bonding characters. The electron densities at the middle of the bond are 0.79 and 0.70 e/Å3 at 200 K and at room temperature, respectively. The refined harmonic thermal factors are in good agreement with the published values. 相似文献
176.
177.
A laser-heated sample in a diamond anvil cell and synchrotron X-ray radiation was used to carry out structural characterization of the phase transformation of Fe2O3 at high pressures (30-96 GPa) and high temperature. The Rh2O3(II) (or orthorhombic perovskite) structure transforms to a new phase, which exhibits X-ray diffraction data that are indicative of a CaIrO3-type structure. The CaIrO3-type structure exhibited an orthorhombic symmetry (space group: Cmcm) that was stable at temperatures of 1200-2800 K and pressure of 96 GPa (the highest pressure used). Unambiguous assignment of such a structure requires experimental evidence for the presence of two Fe species. Based on the equation of state of gold, the phase boundary of the CaIrO3-type phase transformation was P (GPa)=59+0.0022×(T−1200) (K). 相似文献
178.
S. Saitoh H. Tanaka A. Ono Y. Furuhama T. Manabe T. Ihara 《International Journal of Infrared and Millimeter Waves》1986,7(6):795-812
The attenuation of 245.52 GHz millimeter wave was measured through a near ground horizontal path in order to study the anomalous water vapor absorption at the window region. The result demonstrates that the attenuation coefficient includes the quadratic dependence on the water vapor density. The quadratic component of the water vapor density in the expression of the attenuation was assumed to arises from the contribution of water dimers alone, then the concentration of water dimers was estimated adopting the published theoretical water dimers absorption coefficient. The obtained concentration was 0.062% of monomers in number when the water vapor density is 7.5 g/m3. This concentration is in agreement with the published result obtained by way of another method. 相似文献
179.
A diketone precursor of air-stable bis-2-thienyl-2,6-anthracene was prepared and quantitatively converted to the target acene by photoirradiation of the n-π∗ absorption both in solution and as a film, in air. 相似文献
180.
In this paper, we introduce the two-dimensional continuous wavelet transform for the automated strain analysis of the moiré
interference fringe pattern. The Fourier transform method has been widely used for automated analysis of an optical interference
fringe pattern. However, this method is hardly applicable to the analysis of the fringe pattern, which includes large displacement
range or discontinuities. We show the advantages of the wavelet transform method by applying it to experimental results on
composite laminates. 相似文献