全文获取类型
收费全文 | 6556篇 |
免费 | 1123篇 |
国内免费 | 447篇 |
专业分类
化学 | 2478篇 |
晶体学 | 84篇 |
力学 | 1467篇 |
综合类 | 53篇 |
数学 | 242篇 |
物理学 | 3802篇 |
出版年
2024年 | 10篇 |
2023年 | 42篇 |
2022年 | 138篇 |
2021年 | 139篇 |
2020年 | 168篇 |
2019年 | 181篇 |
2018年 | 138篇 |
2017年 | 204篇 |
2016年 | 249篇 |
2015年 | 300篇 |
2014年 | 298篇 |
2013年 | 967篇 |
2012年 | 379篇 |
2011年 | 458篇 |
2010年 | 316篇 |
2009年 | 367篇 |
2008年 | 344篇 |
2007年 | 368篇 |
2006年 | 322篇 |
2005年 | 315篇 |
2004年 | 299篇 |
2003年 | 240篇 |
2002年 | 221篇 |
2001年 | 195篇 |
2000年 | 154篇 |
1999年 | 125篇 |
1998年 | 159篇 |
1997年 | 126篇 |
1996年 | 109篇 |
1995年 | 120篇 |
1994年 | 95篇 |
1993年 | 104篇 |
1992年 | 82篇 |
1991年 | 61篇 |
1990年 | 44篇 |
1989年 | 43篇 |
1988年 | 54篇 |
1987年 | 31篇 |
1986年 | 30篇 |
1985年 | 24篇 |
1984年 | 21篇 |
1983年 | 4篇 |
1982年 | 17篇 |
1981年 | 18篇 |
1980年 | 5篇 |
1979年 | 17篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1973年 | 4篇 |
1972年 | 5篇 |
排序方式: 共有8126条查询结果,搜索用时 15 毫秒
991.
Abstract High-pressure treatment offers to the dairy industry a new technique for food preservation. Very little research is available on the use of high pressure and its potential for cheesemaking. The use of high-pressure treated milk to produce goat cheese has been studied. The effect of high pressure on the ripening process of goat cheese, including the microbiological quality of goat milk and cheese has been included. 相似文献
992.
Abstract A low-temperature high-pressure apparatus was designed using commercial cryogenic equipment. Pressures up to 1 GPa and temperatures down to 40 K can be obtained in a volume of up to 30 cm3. The apparatus is of the piston-cylinder type with a piston diameter of 45 mm, and the pressure can be varied at all temperatures, An adaptive temperature control system keeps the temperature inside the pressure cylinder constant to within ±0.1 K. 相似文献
993.
Abstract The effect of high temperature and high hydrostatic pressure on the residual hydrolytic activity of a commercial Rhizomucor miehei lipase has been studied. Inactivation at high temperature and/or high pressure was carried out. Under non-denaturing pressure conditions, results showed that pressurisation protects enzymes against thermal deactivation. This is in accordance with previous results obtained with enzymes from mesophilic sources, such as invertase and galactosidases. 相似文献
994.
Abstract High pressure electrical measurements were conducted in the antiferromagnetic insulator CoI, using a miniature Diamond Anvil Cell (DAC). The existence of a Mott Transition predicted from high pressure 129I Mgssbauer Spectroscopy (MS)1 has been verified. At about 8 GPa the system becomes metal1ic as evidenced by the temperature behavior of the conductivity. The conductivity at room temperature, however, still increases with increasing pressure, leveling off at 11 GPa. The metallic behavior in the 8 -11 GPa is explained by coexistence of metallic and insulating clusters via a percolating process. Above 11 GPa the material is completely metallic. This mechanism is consistent with the MS findings. 相似文献
995.
996.
H. D. Hochheimer F. Widulle J. Th. Held G. Strehl R. T. Kotitschke A. R. Adams 《高压研究》2013,33(1-6):41-48
Abstract We present the design of a device for the simultaneous application of uniaxial stress and hydrostatic pressure. This new apparatus will for the first time allow measurements at constant strain. Results of the simultaneous application of uniaxial stress and hydrostatic pressure to a semiconductor laser are presented and discussed. 相似文献
997.
Abstract The influence of P, T-parmeters and duration of heat when synthesizing diamond in high pressure apparatus both of recessed anvil-type and cylindrical type (belt-type) on properties of diamond powders was studied. The dependence of pressure in reaction cells on temperature of force elements of apparatus in initial state and on efficiency of high pressure production in a reaction cell before heating was shown. 相似文献
998.
Abstract The optical absorption of the diluted magnetic semiconductor Zn1?xCOxSe (x = 0.02) has been measured at room temperature under hydrostatic pressure up to 14GPa in a membrane diamond-anvil cell. We found two absorption features: (i) an absorption structure in the energy range 1.6?1.8eV, with a negligible pressure shift (i.e., 0.45 ± 0.05 meV/GPa) which we have identified as the Co2+(3d7) internal transition 4A2(F)→+4T1(P) and (ii) an onset in the energy range 2?2.7eV which redshifts with pressure (?8.1±0.6meV/GPa). We have attributed such absorption edge to charge transfer between the ZnSe valence band and the Co2+(3d7) levels. 相似文献
999.
Alain Polian 《高压研究》2013,33(1-6):205-217
Abstract The scattering of light by elementar excitations in the matter is results in two phenomena, discriminated by the zero wavevector frequency of the excitation: if this frequency is zero, one deals with Brillouin scattering, and with Raman scattering in the other case. Brillouin scattering results from the interaction of light with thermal excitations (acoustic phonons in a crystal) of a material, or, from a classical point of view, with density waves. Contrary to Raman scattering, the selection rules allow always the observation of at least one mode. It is a powerful technic in the study of rare gases under pressure: at ambient temperature, rare gases crystallize in the face centered cubic structure (except helium which structure was recently found to be hexagonal) and are therefore Raman and infrared inactive. Experimental results will be reviewed on rare gases and rare gas mixtures in the fluid phase, like He-Ne and He-H2. These results will be discussed in relation with recent measurements of the frequency of global oscillations of Jupiter. 相似文献
1000.
Yongrong Shen Kevin L. Bray Marek Grinberg Justyna Barzowska Irena Sókolska 《高压研究》2013,33(1-6):125-130
Abstract The effect of pressure on the luminescence spectrum of the weak field system Cr3+ : LiTaO3 is presented. By using pressure to induce a low to high crystal field strength transition, we demonstrate the ability of pressure to identify distinct dopant bonding environments in luminescent materials. 相似文献