全文获取类型
收费全文 | 60360篇 |
免费 | 12476篇 |
国内免费 | 4664篇 |
专业分类
化学 | 57237篇 |
晶体学 | 632篇 |
力学 | 1822篇 |
综合类 | 219篇 |
数学 | 4702篇 |
物理学 | 12888篇 |
出版年
2024年 | 99篇 |
2023年 | 541篇 |
2022年 | 968篇 |
2021年 | 1196篇 |
2020年 | 2248篇 |
2019年 | 3482篇 |
2018年 | 1927篇 |
2017年 | 1512篇 |
2016年 | 4489篇 |
2015年 | 4655篇 |
2014年 | 4770篇 |
2013年 | 5776篇 |
2012年 | 5111篇 |
2011年 | 4432篇 |
2010年 | 4352篇 |
2009年 | 4224篇 |
2008年 | 3953篇 |
2007年 | 3214篇 |
2006年 | 2757篇 |
2005年 | 2705篇 |
2004年 | 2308篇 |
2003年 | 2104篇 |
2002年 | 2904篇 |
2001年 | 2036篇 |
2000年 | 1751篇 |
1999年 | 913篇 |
1998年 | 483篇 |
1997年 | 416篇 |
1996年 | 380篇 |
1995年 | 307篇 |
1994年 | 243篇 |
1993年 | 197篇 |
1992年 | 188篇 |
1991年 | 192篇 |
1990年 | 138篇 |
1989年 | 105篇 |
1988年 | 73篇 |
1987年 | 55篇 |
1986年 | 62篇 |
1985年 | 65篇 |
1984年 | 32篇 |
1983年 | 27篇 |
1982年 | 21篇 |
1981年 | 26篇 |
1980年 | 10篇 |
1978年 | 6篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1936年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Zhang Hengkai Zhang Yaokang Yang Guang Ren Zhiwei Yu Wei Shen Dong Lee Chun-Shing Zheng Zijian Li Gang 《中国科学:化学(英文版)》2019,62(7):875-882
From a base material of conductive polymer(poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate),PEDOT:PSS),a flexible and high-conductivity(as low as 45Ω/sq)transparent electrode was fabricated on polydimethylsiloxane elastomer by an acid treatment and transfer process.Combined with the D-sorbitol-doped PEDOT:PSS electric glue,we successfully demonstrated a vacuum-free and ambient lamination fabrication process for semi-transparent perovskite solar cells using triple cation Cs_(0.05)(MA_(0.17)FA_(0.83))_(0.95)Pb(I_(0.83)Br_(0.17))_3perovskite.By this manufacturing-friendly lamination process,we fabricated semitransparent perovskite solar cell devices with power conversion efficiencies up to 16.4%and variable transparencies. 相似文献
922.
Two stable heterometal‐organic frameworks, {Na[LnCo(DATP)2(Ac)(H2O)](NO3)?DMA?11 H2O}n (Ln=Er( 1 ) and Yb( 2 )), have been prepared with H2DATP (4′‐(3,5‐dicarboxyphenyl)‐2,2′:6′,2′′′‐terpyridine) as organic building block. These two isostructural compounds featuring two‐dimensional layer architectures possess outstanding thermal stabilities and excellent chemical stabilities in common organic solvents and different acid/base solutions with pH range changing from 1 to 13. Moreover, compounds 1 and 2 serving as heterogeneous catalysts can efficiently catalyse the CO2 fixation reaction with various aziridines to result in corresponding oxazolidinones at 70 °C. Importantly, a good recyclable performance of 1 for at least 10 cycles is observed based on the experimental results, which are further confirmed by PXRD, TGA and ICP analyses. 相似文献
923.
924.
Nathamgari S. S. P. Dong S. Hosseinian E. Lauhon L. J. Espinosa H. D. 《Experimental Mechanics》2019,59(3):349-359
Experimental Mechanics - Nanoelectromechanical (NEMS) systems fabricated using atomically thin materials have low mass and high stiffness and are thus ideal candidates for force and mass sensing... 相似文献
925.
Zhang Min-Min Hou Jiao-Jiao Wu Chun Yang Xiong 《International Journal of Theoretical Physics》2019,58(6):1711-1720
We propose a single-photon router that is made of three coupled-resonator forming a Π-type waveguide. The two atoms embedded in the two junctions, which have the distance of 2d, are used as quantum switch to control single photons routing. We find that the scattered rate depend on the incident single photons come from either infinite CRWs or semi-infinite CRWs, and the boundary can enhance the transfer rate.
相似文献926.
Flexible control of building blocks of photonic crystals enables achieving desirable band structures. Exploration of photonic band extrema has brought many fantastic features to design artificial optical materials, such as Brillouin‐zone‐corner extrema for valley photonic materials and zone‐center extremum for zero‐index metamaterials. However, two such kinds of extrema are always found independently in different photonic crystals. In this work, a kind of valley photonic crystals possessing both zone‐center and zone‐corner band extrema almost at the same frequency is proposed. Inspired by antennas theory, a three‐antenna array (TAA) source is devoted to individually manipulate each extremum. The correlation coefficient is given to determine the coupling efficiency between the TAA source and extrema eigenmodes. By using a source with a high correlation coefficient, these extrema bulk states are selectively excited consistent with their eigenfields. Furthermore, three control cases are shown that multiple extrema points are simultaneously excited, in order to confirm the validity of the correlation coefficient. Finally, a potential application of a beam‐steering device is proposed through selective excitation of ternary extrema. This work develops binary valley states into ternary mix states, rendering more degrees of freedom for on‐chip optical information transport, particularly for beam steering and mode division multiplexing. 相似文献
927.
928.
929.
930.
A method to generate NOON states with three photons by injecting photons in an array of three waveguides is presented. Conditional measurements project the wave function in a given (desired) state. In passing, it is shown how the array of three waveguides, that effectively reproduces the interaction of three fields, may be reduced to the interaction of two fields. 相似文献