全文获取类型
收费全文 | 185222篇 |
免费 | 1058篇 |
国内免费 | 262篇 |
专业分类
化学 | 93283篇 |
晶体学 | 2658篇 |
力学 | 9571篇 |
综合类 | 7篇 |
数学 | 21653篇 |
物理学 | 59370篇 |
出版年
2020年 | 1915篇 |
2019年 | 2357篇 |
2018年 | 3492篇 |
2017年 | 3587篇 |
2016年 | 4290篇 |
2015年 | 2026篇 |
2014年 | 3730篇 |
2013年 | 7368篇 |
2012年 | 5896篇 |
2011年 | 6948篇 |
2010年 | 5752篇 |
2009年 | 5773篇 |
2008年 | 6717篇 |
2007年 | 6644篇 |
2006年 | 5924篇 |
2005年 | 5264篇 |
2004年 | 5070篇 |
2003年 | 4596篇 |
2002年 | 4721篇 |
2001年 | 5111篇 |
2000年 | 3814篇 |
1999年 | 2881篇 |
1998年 | 2686篇 |
1997年 | 2510篇 |
1996年 | 2331篇 |
1995年 | 2089篇 |
1994年 | 2046篇 |
1993年 | 2083篇 |
1992年 | 2123篇 |
1991年 | 2410篇 |
1990年 | 2349篇 |
1989年 | 2414篇 |
1988年 | 2308篇 |
1987年 | 2314篇 |
1986年 | 2152篇 |
1985年 | 2702篇 |
1984年 | 2728篇 |
1983年 | 2342篇 |
1982年 | 2409篇 |
1981年 | 2321篇 |
1980年 | 2115篇 |
1979年 | 2428篇 |
1978年 | 2588篇 |
1977年 | 2677篇 |
1976年 | 2781篇 |
1975年 | 2568篇 |
1974年 | 2493篇 |
1973年 | 2663篇 |
1972年 | 2158篇 |
1971年 | 1976篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
A. K. Nasirov G. Giardina A. I. Muminov W. Scheid U. T. Yakhshiev 《Acta Physica Hungarica A》2004,19(1-2):109-120
The effect of entrance channel on decrease of the complete fusion cross sections and on the yield of reaction products are associated with the quasifission which depends on the mass asymmetry and shell structure of colliding nuclei. In reactions of massive projectile and target nuclei, the competition between complete fusion and quasifission appears at the stage of compound nucleus formation, in addition to the increase of the fission probability. It is shown that the yield of quasifission products may be symmetric or asymmetric in dependence on peculiarities of shell structure of reaction fragments. Marima of mass or charge distributions are connected with the peculiarities of shell structure of reaction fragments. 相似文献
995.
S. Burachas S. Beloglovsky D. Elizarov I. Makov Yu. Saveliev N. Vassilieva M. Ippolitov V. Manko S. Nikulin A. Nyanin A. Vasiliev A. Apanasenko G. Tamulaitis 《Radiation measurements》2004,38(4-6):367-370
Technological conditions ensuring growth of optically homogeneous lead tungstate (PWO) crystals are reported. It is shown that the basic scintillator characteristics of PWO grown from highly purified raw material and properly doped with lanthanides are mainly determined by inclusions of oxides W1−yLyO3−x (L=Y, La, Gd; 0<x<0.3). Moreover, surface-located inclusions with structure close to tungstenite may also be of importance. It is demonstrated that the scintillation properties can be intentionally designed by varying the oxygen content in the inclusions x and the surface structure. The optimal value for x and the most favorable surface structure are achieved by proper thermal regimes and environment content during the crystal annealing. The results enabled low-cost fabrication of PWO scintillators with steady and reproducible characteristics acceptable for the CERN project ALICE and ensured production of PWO on an industrial scale by “North Crystals” company at a rate of 125–135 crystals per year from every growth apparatus. 相似文献
996.
I. I. Milman E. V. Moiseykin S. V. Nikiforov S. G. Mikhailov V. I. Solomonov 《Radiation measurements》2004,38(4-6):443
The spectra of pulsed cathodoluminescence (PCL) and thermoluminescence (TL) in TLD-500 detectors, which were exposed to a strong beam from a pulsed electron accelerator, have been studied. Additional bands in the PCL spectrum and new peaks in the TL curves, which are due to impurity ions, have been revealed. Luminescence bands of F- and F+-centers cannot be used in the dosimetry of strong electron beams using TLD-500 detectors because of the saturation of dose dependence and the decrease in the TL yield. It is shown that high doses from these beams can be measured by recording TL in the luminescence band of impurity titanium ions. 相似文献
997.
V. F. Radantsev V. V. Kruzhaev G. I. Kulaev 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):396
The Rashba effect in metal–insulator–semiconductor (MIS) structures based on zero-gap HgCdTe is investigated experimentally and theoretically over a wide doping range NA–ND=3×1015–3×1018 cm−3. Increase of doping enlarges the magnitude of the effect at the same 2D concentration and strengthens a gate-voltage dependence of the Rashba splitting. The results demonstrate values of Rashba polarization as high as PR0.5 and a capability to control the Rashba effect strength at constant electron concentration. 相似文献
998.
V. I. Isakov 《Physics of Atomic Nuclei》2004,67(5):911-919
On the basis of a detailed analysis of available experimental data, the spectrum of single-particle states and the isotopic dependence of spin-orbit splitting are determined for nuclei in the vicinity of the doubly magic nuclide 48Ca. The spectrum of excited states of the isobaric nucleus 48Sc is calculated. 相似文献
999.
Backscattered-particle production is studied by means of a detailed simulation of cascade processes in a dense medium. The energy dependence of the albedo and the spatial and angular distributions of various components of this flux are analyzed. 相似文献
1000.
The interaction between the rotational degrees of freedom of a diatomic impurity molecule and phonon excitations of a two-dimensional atomic matrix commensurate to the substrate is investigated theoretically. It is shown that the translational-rotational interaction leads to renormalization of the crystal field constants and a change in the form of the operator for the rotational kinetic energy as compared to the corresponding expression for a free rotator. The contribution from the rotational degrees of freedom of impurities to the low-temperature heat capacity of a diluted solution of diatomic molecules in the two-dimensional atomic matrix is calculated. The possibility of experimentally observing the predicted effects is discussed. 相似文献