全文获取类型
收费全文 | 708篇 |
免费 | 16篇 |
国内免费 | 5篇 |
专业分类
化学 | 556篇 |
晶体学 | 8篇 |
力学 | 17篇 |
数学 | 30篇 |
物理学 | 118篇 |
出版年
2023年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 16篇 |
2015年 | 10篇 |
2014年 | 21篇 |
2013年 | 36篇 |
2012年 | 38篇 |
2011年 | 43篇 |
2010年 | 22篇 |
2009年 | 17篇 |
2008年 | 32篇 |
2007年 | 39篇 |
2006年 | 44篇 |
2005年 | 49篇 |
2004年 | 39篇 |
2003年 | 23篇 |
2002年 | 28篇 |
2001年 | 16篇 |
2000年 | 16篇 |
1999年 | 15篇 |
1998年 | 13篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 15篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 17篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1969年 | 3篇 |
排序方式: 共有729条查询结果,搜索用时 218 毫秒
1.
2.
Yasuhiro Ikezoe Sadahiro Ishizaki Hiroharu Yui Masanori Fujinami Tsuguo Sawada 《Analytical sciences》2004,20(3):435-440
The oscillation of the interfacial tension and electrical potential at a water/nitrobenzene interface was observed with homologous anionic surfactant molecules, sodium-alkyl-sulfates. Concerning small molecules with a short hydrophobic carbon chain, the oscillation period and amplitude decreased with a decrease of the length of the alkyl chain. On the other hand, when surfactant molecules with a long hydrophobic carbon chain were used, no remarkable periodic oscillation occurred after the first oscillation. In all systems, an interfacial flow by Marangoni convection was observed when the oscillation took place. By monitoring the movement of carbon powder scattered on the liquid/liquid interface with a CCD camera, we could observe that the liquid/liquid interface expanded outward from the area on which the surfactant molecules adsorbed when the oscillation occurred. When the small molecule was used, the speed of expansion of the interface (flow speed) was small and shrinkage followed by expansion of the interface repeatedly occurred. However, when the large molecule was used, the flow speed was large and expansion occurred only one time. These results show that hydrodynamic factors and surface activities are important in chemical oscillation systems. 相似文献
3.
Molecules in inhomogeneous liquid environments, such as air/liquid, liquid/liquid, solid/liquid interfaces interact with each other specifically, and sometimes form characteristic structures and emerge unique properties. Here, we introduce two newly developed spectroscopic techniques, the total-internal-reflection ultrafast transient lens method (TIR-UTL) and second harmonic generation-coherent vibrational spectroscopy (SHG-CVS), to investigate the characteristic behaviors of molecules in such inhomogeneous environments. TIR-UTL probes the refractive-index change with sub-picosecond resolution and provides information on ultrafast changes in the population, density, and thermal properties, such as temperature increase and energy transfer from the solute molecules to the surrounding solvent molecules. On the other hand, SHG-CVS probes nonlinear susceptibility changes at the interfacial areas, and is expected to provide spectroscopic information on the low-frequency vibrational modes that reflect the corrective motion of the molecules in such an inhomogeneous environment. These new approaches are based on pump-probe techniques utilizing (ultra) short laser pulses. They are expected to provide further information on inhomogeneous environments from the viewpoints of solute-solvent interactions, changes in the molecular orientation, and the corrective motion of molecules at liquid interfaces. 相似文献
4.
5.
6.
7.
Yang Ju Yo Hirosawa Masumi Saka Hiroyuki Abé 《International Journal of Infrared and Millimeter Waves》2003,24(3):391-397
We developed a compact equipment working at 94 GHz to replace the commonly used network analyzer for nondestructive testing of materials. The compact equipment was designed to measure the variations in the amplitude and phase of the reflected signal from the material relative to a reference signal. A good accuracy of the amplitude and phase measurement of the equipment was obtained in the confirmative experiments. The distribution of a drop of water in a wood plate is clearly visible in the millimeter wave images obtained by the amplitude and phase measurement. 相似文献
8.
9.
10.
Sawada Y. Seki S. Sano M. Miyabayashi N. Ninomiya K. Iwasawa A. Tsugoshi T. Ozao R. Nishimoto Y. 《Journal of Thermal Analysis and Calorimetry》2004,77(3):751-757
Tin-doped indium oxide In2O3 (indium-tin-oxide) transparent conducting films were fabricated on silicon substrates by a dip coating process. The thermal
analysis of the ITO films was executed by temperature-programmed desorption (TPD) or thermal desorption spectroscopy (TDS)
in high vacuum. Gas evolution from the ITO film mainly consisted of water vapor. The total amount of evolved water vapor increased
on increasing the film thickness from approx. 25 to 250 nm and decreased by increasing the preparation temperature from 365
to 600°C and by annealing at the same temperature for extra 10 h. The evolution occurred via two steps; the peak temperatures
for 250 nm thick films were approx. 100-120 and 205-215°C. The 25 nm thick films evolved water vapor at much higher temperatures;
a shoulder at approx. 150-165°C and a peak at approx. 242°C were observed. The evolution temperatures increased by increasing
the preparation and the annealing temperatures except in case of the second peak of the 25 nm thick films. The evolution of
water vapor at high temperature was tentatively attributed to thermal decomposition of indium hydroxide, In(OH)3, formed on the surface of the nm-sized ITO particles.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献