全文获取类型
收费全文 | 44292篇 |
免费 | 1914篇 |
国内免费 | 1584篇 |
专业分类
化学 | 23929篇 |
晶体学 | 750篇 |
力学 | 2147篇 |
综合类 | 104篇 |
数学 | 4337篇 |
物理学 | 16523篇 |
出版年
2022年 | 477篇 |
2021年 | 637篇 |
2020年 | 683篇 |
2019年 | 632篇 |
2018年 | 827篇 |
2017年 | 753篇 |
2016年 | 1108篇 |
2015年 | 859篇 |
2014年 | 1301篇 |
2013年 | 2272篇 |
2012年 | 2183篇 |
2011年 | 2609篇 |
2010年 | 1963篇 |
2009年 | 1910篇 |
2008年 | 2187篇 |
2007年 | 2128篇 |
2006年 | 1933篇 |
2005年 | 1630篇 |
2004年 | 1467篇 |
2003年 | 1250篇 |
2002年 | 1197篇 |
2001年 | 1592篇 |
2000年 | 1133篇 |
1999年 | 930篇 |
1998年 | 689篇 |
1997年 | 661篇 |
1996年 | 587篇 |
1995年 | 525篇 |
1994年 | 474篇 |
1993年 | 429篇 |
1992年 | 484篇 |
1991年 | 483篇 |
1990年 | 467篇 |
1989年 | 424篇 |
1988年 | 442篇 |
1987年 | 432篇 |
1986年 | 376篇 |
1985年 | 441篇 |
1984年 | 464篇 |
1983年 | 340篇 |
1982年 | 384篇 |
1981年 | 371篇 |
1980年 | 311篇 |
1979年 | 395篇 |
1978年 | 375篇 |
1977年 | 392篇 |
1976年 | 390篇 |
1975年 | 339篇 |
1974年 | 317篇 |
1973年 | 333篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
1.
Chuprin A. S. Belova S. A. Bugaenko M. G. Vologzhanina A. V. Loktev A. S. Voloshin Ya. Z. Buznik V. M. Dedov A. G. 《Kinetics and Catalysis》2022,63(1):108-116
Kinetics and Catalysis - A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the... 相似文献
2.
Zhang Bing Yang Jie-qin Liu Ying Hu Bin Yang Yang Zhao Li Lu Qiang 《Cellulose (London, England)》2022,29(12):6565-6578
Cellulose - Heating is essential in various biomass pre-treatments and thermal conversion processes. It is of practical significance to study the characteristics of cellulose-lignin and... 相似文献
3.
High Energy Chemistry - Modification of Polyvinylidene fluoride (PVDF) by radiation grafting is a research hotspot in recent years. In this study, the monomer 2-Hydroxyethyl methacrylate (HEMA) was... 相似文献
4.
Alawainati F. A. Manaa H. Henari F. Z. Biyiklioglu Z. Arslan T. Jaafar A. 《Journal of Applied Spectroscopy》2021,88(5):951-957
Journal of Applied Spectroscopy - Detailed measurements of nonlinear optical properties and optical limiting for four phthalocyanine (Pc) derivatives (PcCo, PcCu, PcMn, and PcSi) are reported. The... 相似文献
5.
Siberian Mathematical Journal - A lattice homomorphism between quasi-Banach lattices is known to be compact if and only if it is a sum of a series of rank one lattice... 相似文献
6.
International Journal of Theoretical Physics - We consider the stationary state of a spin-orbit coupled (SOC) binary Bose-Einstein condensates with dipole-dipole interaction (DDI). Our results are... 相似文献
7.
Design of diamond-shape photonic crystal fiber polarization filter based on surface plasma resonance effect 下载免费PDF全文
A novel plasmonic polarization filter based on the diamond-shape photonic crystal fiber(PCF) is proposed. The resonant coupling characteristics of the PCF polarization filter are investigated by the full-vector finite-element method. By optimizing the geometric parameters of the PCF, when the fiber length is 5 mm, the polarization filter has a bandwidth of 990 nm and an extinction ratio(ER) of lower than -20 dB. Moreover, a single wavelength polarization filter can also be achieved, along with an ER of -279.78 dB at wavelength 1.55 μm. It is believed that the proposed PCF polarization filter will be very useful in laser and optical communication systems. 相似文献
8.
Dr. Yong-Sheng Wei Dr. Liming Sun Miao Wang Dr. Jinhua Hong Dr. Lianli Zou Hongwen Liu Dr. Yu Wang Dr. Mei Zhang Dr. Zheng Liu Prof. Yinwei Li Prof. Satoshi Horike Prof. Kazu Suenaga Prof. Qiang Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16147-16156
Understanding the thermal aggregation behavior of metal atoms is important for the synthesis of supported metal clusters. Here, derived from a metal–organic framework encapsulating a trinuclear FeIII2FeII complex (denoted as Fe3) within the channels, a well-defined nitrogen-doped carbon layer is fabricated as an ideal support for stabilizing the generated iron nanoclusters. Atomic replacement of FeII by other metal(II) ions (e.g., ZnII/CoII) via synthesizing isostructural trinuclear-complex precursors (Fe2Zn/Fe2Co), namely the “heteroatom modulator approach”, is inhibiting the aggregation of Fe atoms toward nanoclusters with formation of a stable iron dimer in an optimal metal–nitrogen moiety, clearly identified by direct transmission electron microscopy and X-ray absorption fine structure analysis. The supported iron dimer, serving as cooperative metal–metal site, acts as efficient oxygen evolution catalyst. Our findings offer an atomic insight to guide the future design of ultrasmall metal clusters bearing outstanding catalytic capabilities. 相似文献
9.
10.
We study the full counting statistics of transport electrons through a semiconductor two-level quantum dot with Rashba spin–orbit (SO) coupling, which acts as a nonabelian gauge field and thus induces the electron transition between two levels along with the spin flip. By means of the quantum master equation approach, shot noise and skewness are obtained at finite temperature with two-body Coulomb interaction. We particularly demonstrate the crucial effect of SO coupling on the super-Poissonian fluctuation of transport electrons, in terms of which the SO coupling can be probed by the zero-frequency cumulants. While the charge currents are not sensitive to the SO coupling. 相似文献