全文获取类型
收费全文 | 618篇 |
免费 | 6篇 |
专业分类
化学 | 233篇 |
晶体学 | 17篇 |
力学 | 20篇 |
数学 | 62篇 |
物理学 | 292篇 |
出版年
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 18篇 |
2019年 | 10篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 25篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 37篇 |
2011年 | 35篇 |
2010年 | 20篇 |
2009年 | 30篇 |
2008年 | 19篇 |
2007年 | 20篇 |
2006年 | 28篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1970年 | 12篇 |
1969年 | 11篇 |
1968年 | 9篇 |
1967年 | 8篇 |
排序方式: 共有624条查询结果,搜索用时 15 毫秒
11.
V. A. Petrova L. A. Nud’ga A. M. Bochek V. E. Yudin I. V. Gofman V. Yu. Elokhovskii I. P. Dobrovol’skaya 《Polymer Science Series A》2012,54(3):224-230
The rheological properties of chitosan solutions in a 2% aqueous solution of acetic acid with added montmorillonite nanoparticles
and the mechanical properties and structural organization of chitosan-based composite films are studied. The interaction between
the polymer functional groups and surface charges of nanoplatelets is confirmed by conductometric and potentiometric measurements.
With the use of a X-ray diffraction analysis, it is shown that the nanoparticles in films are in the exfoliated and intercalated
states. The incorporation of up to 10 wt % modified montmorillonite nanoparticles into the chitosan matrix results in a successive
increase in rigidity and a decrease in the elongation at break. 相似文献
12.
13.
14.
V. E. Smirnova E. N. Popova V. M. Svetlichnyi L. A. Myagkova A. N. Orekhov V. E. Yudin A. M. Muzafarov E. A. Tatarinova 《Russian Journal of Applied Chemistry》2011,84(10):1800-1804
The effect exerted by thermal aging in air at 350°C on the thermal and mechanical properties of composite films prepared on
the basis of heat-resistant polyimide PM and non-film-forming polymethylphenylsiloxane (PMPS) was examined. The phase segregation
of polymeric composites of various compositions and the thermal aging rate were evaluated. 相似文献
15.
A. M. Bochek N. M. Zabivalova I. I. Gavrilova I. V. Gofman I. V. Abalov E. N. Popova V. E. Yudin V. K. Lavrent’ev E. F. Panarin 《Polymer Science Series A》2014,56(2):158-168
The rheological properties of dilute and moderately concentrated solutions of methyl cellulose blends with poly(N-methyl-N-vinylacetamide) in water and dimethylacetamide are studied, and the stressstrain characteristics of the composite films based on these blends are estimated. DSC, X-ray diffraction, and thermomechanical analysis are used to investigate the structural organization of composite films, to estimate the temperatures of relaxation transitions, and to determine the composition ranges in which the polymers are compatible and form mixed structures. 相似文献
16.
17.
Yu. N. Sazanov S. M. Krutov A. V. Gribanov T. N. Spirina E. M. Kulikova G. N. Fedorova E. N. Popova I. V. Sumerskii V. Yu. Elokhovskii V. E. Yudin 《Russian Journal of Applied Chemistry》2011,84(7):1238-1245
Interaction of hydrolysis lignin with polyacrylonitrile in water-dimethyl sulfoxide solution in the presence of an activator
was studied, and the properties of the products were examined. 相似文献
18.
An electroded heterostructure consisting of a dye layer sandwiched between two polymer ferroelectric layers is discussed.
The dye layer plays a role of the probe of the electric field measured by an electroabsorption technique. Using this new method
the electric field in ferroelectric and dielectric layers can be measured separately. When an a.c. voltage is applied to the
heterostructure, the electric field in the dye layer increases 2.2 times (up to 0.55 GV/m), whereas the field in the ferroelectric
decreases 2 times with respect to the average field in the entire structure. Moreover, the dye layer sandwiched between the
ferroelectric layers may stand without breakdown the fields 5–7 times higher than a neat reference dye layer confined between
metal electrodes. Therefore, the performance of electro-optical, electromechanical and other field controlled devices may
be improved considerably when their functional materials are placed between ferroelectrics layers. 相似文献
19.
The conditions under which the influence of the discharge circuitry inductance on the efficiency of pulsed-periodic copper-vapor lasers is weak are determined. It is shown that for efficient pumping of the lasing transitions of Cu atom in these lasers it is advisable to form an excitation pulse having steep edges of the voltage applied to the discharge tube with the duration spanning the pumping period and termination of the lasing process providing, at the same time, the conditions for aperiodic behavior of the discharge during the excitation pulse. Such a pumping pulse can be formed due to a partial discharge of the storage capacitor in the laser discharge circuit. It is also shown that under such conditions of excitation the efficiency of copper-vapor laser (CVL) with respect to the energy pumped into the active element can reach 10%. 相似文献
20.