全文获取类型
收费全文 | 14323篇 |
免费 | 2959篇 |
国内免费 | 2130篇 |
专业分类
化学 | 9228篇 |
晶体学 | 282篇 |
力学 | 1784篇 |
综合类 | 144篇 |
数学 | 1443篇 |
物理学 | 6531篇 |
出版年
2024年 | 26篇 |
2023年 | 175篇 |
2022年 | 421篇 |
2021年 | 398篇 |
2020年 | 584篇 |
2019年 | 487篇 |
2018年 | 495篇 |
2017年 | 567篇 |
2016年 | 731篇 |
2015年 | 635篇 |
2014年 | 906篇 |
2013年 | 1472篇 |
2012年 | 1014篇 |
2011年 | 977篇 |
2010年 | 816篇 |
2009年 | 895篇 |
2008年 | 935篇 |
2007年 | 992篇 |
2006年 | 872篇 |
2005年 | 747篇 |
2004年 | 686篇 |
2003年 | 653篇 |
2002年 | 483篇 |
2001年 | 482篇 |
2000年 | 464篇 |
1999年 | 359篇 |
1998年 | 357篇 |
1997年 | 275篇 |
1996年 | 253篇 |
1995年 | 220篇 |
1994年 | 209篇 |
1993年 | 156篇 |
1992年 | 136篇 |
1991年 | 94篇 |
1990年 | 68篇 |
1989年 | 70篇 |
1988年 | 60篇 |
1987年 | 42篇 |
1986年 | 42篇 |
1985年 | 32篇 |
1984年 | 29篇 |
1983年 | 8篇 |
1982年 | 24篇 |
1981年 | 8篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1973年 | 5篇 |
1971年 | 3篇 |
1957年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
201.
Changes in the physicochemical properties of transferrin upon chemical derivatization with ceramides
M. A. Egea M. L. García M. A. Alsina C. Mestres F. Reig 《Colloid and polymer science》1994,272(5):570-576
The interaction of native and derivatized transferrin with lecithin, cholesterol and their mixtures was studied using monomolecular layers of phospholipids. Moreover, the thermodynamic parameters corresponding to these interactions: the mixing excess free energy, interaction energy, and interaction parameter were also calculated.The ability of these two proteins to insert into monolayers was studied working at constant area.The formation of aggregates or secondary structures in solution was determined by the fluorescence and polarization values of ANS (anilinonaphthalene sulfonate), measured at different protein/ANS relationships.Abbreviations TF
Transferrin
- DTF
derivatized transferrin
- PC
lecithin
- CHOL
cholesterol
- CER
ceramides
- ANS
anilinonaphthalene sulfonate
- TNBS
trinitro benzenesulfonate method 相似文献
202.
203.
Li Jiang Fushen Lu Qing Chang Yang Liu Huibiao Liu Yuliang Li Wei Xu Guanglei Cui Junpeng Zhuang Xiaofang Li Shu Wang Yinglin Song Daoben Zhu 《Chemphyschem》2005,6(3):481-486
An ultrathin composite film containing anionic Ag-His complexes (His: L-Histidine) and oppositely charged BH-PPV was fabricated by means of the electrostatic layer-by-layer self-assembly technique. UV/Vis spectra showed a continuous deposition process of Ag-His complexes and BH-PPV. The film structure was characterized by using small-angle X-ray diffraction, AFM, and SEM. The nonlinear optical properties of the ultrathin film were studied by using the Z-scan technique with a laser duration of 8 ns at a wavelength of 532 nm. The film sample exhibited a strong nonlinear saturated absorption, with an alpha2 value of -3.9 x 10(-5) mW(-1) and a self-defocusing effect with an n2 value of -4.78 x 10 (-12) m2W(-1). 相似文献
204.
205.
206.
采用氧化铝模板结合交流电沉积技术制备纯银纳米线, 然后通过化学还原方法, 并控制加入的金盐的量, 在已制备好的银线表面包裹不同厚度的金壳层, 得到具有核壳结构的Ag核Au壳复合纳米线. 采用电子显微镜(SEM, TEM)和表面增强拉曼光谱对该复合结构纳米线进行相关表征, 纳米线的表面形貌与加入的金盐的量有关. 以苯硫酚(TP)和对巯基苯胺(PATP)为探针分子, 研究了此类复合纳米线的表面增强拉曼散射效应. 并以PATP在金银纳米线表面吸附的表面增强拉曼光谱的差别为探针, 表征了复合纳米线表面金的包裹程度, 结果表明一定厚度的包裹程度可制备无针孔效应的核壳结构金银复合纳米线. 相似文献
207.
208.
209.
Transmission gratings of holographic polymer-dispersed liquid crystals (HPDLC) are prepared under controlled reaction conditions by adding various amounts of chain-transfer agent (CTA). The resulting films have a higher gel content with lower cross-link density, less dark reaction, less grating shrinkage with much smoother LC/polymer interfaces, smaller induction period, and fast saturation of diffraction efficiency, which shows a maximum of 95 % with 1 % CTA. An optimum LC content of 35 % is verified on the basis of morphology and reaction kinetics. 相似文献
210.
Xianfeng?You Feng?Chen Jinlong?ZhangEmail author 《Journal of Sol-Gel Science and Technology》2005,34(2):181-187
TiO2 powders were prepared by sol–gel template method and calcined under different conditions. XRD, BET and TEM were used to characterize the TiO2 powders obtained. The photocatalytic activity of TiO2 was investigated by the degradation of methyl orange. It was found that TiO2 powder has the highest photocatalytic activity at a calcination temperature of 673 K. The effects of physical properties such as surface area, crystallinity and crystal phase on the photocatalytic activity of TiO2 were discussed. 相似文献