全文获取类型
收费全文 | 1837篇 |
免费 | 406篇 |
国内免费 | 699篇 |
专业分类
化学 | 1396篇 |
晶体学 | 37篇 |
力学 | 167篇 |
综合类 | 102篇 |
数学 | 261篇 |
物理学 | 979篇 |
出版年
2024年 | 5篇 |
2023年 | 22篇 |
2022年 | 78篇 |
2021年 | 73篇 |
2020年 | 71篇 |
2019年 | 58篇 |
2018年 | 61篇 |
2017年 | 109篇 |
2016年 | 48篇 |
2015年 | 85篇 |
2014年 | 94篇 |
2013年 | 134篇 |
2012年 | 111篇 |
2011年 | 137篇 |
2010年 | 151篇 |
2009年 | 156篇 |
2008年 | 177篇 |
2007年 | 164篇 |
2006年 | 144篇 |
2005年 | 133篇 |
2004年 | 109篇 |
2003年 | 89篇 |
2002年 | 84篇 |
2001年 | 94篇 |
2000年 | 97篇 |
1999年 | 46篇 |
1998年 | 30篇 |
1997年 | 34篇 |
1996年 | 29篇 |
1995年 | 18篇 |
1994年 | 29篇 |
1993年 | 31篇 |
1992年 | 29篇 |
1991年 | 21篇 |
1990年 | 29篇 |
1989年 | 24篇 |
1988年 | 26篇 |
1987年 | 21篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 6篇 |
1983年 | 19篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1959年 | 2篇 |
排序方式: 共有2942条查询结果,搜索用时 15 毫秒
991.
本文通过液相化学还原和热还原联合作用制备了柔性透明导电石墨烯膜.阳极氧化铝(AAO)模板在制备过程中既作为抽滤的滤网,又作为热还原处理时支撑石墨烯膜的衬底,制成的柔性透明石墨烯膜对波长为540—840 nm的可见光透光率为80%,面电阻为850 Ω/平方,这与化学气相沉积法制备的石墨烯膜(280—770 Ω/平方)相近,而低于溶液法制备的石墨烯膜(通常是103—104 Ω/平方). 相似文献
992.
993.
When a population structure is modelled as a square lattice,the cooperation may be improved for an evolutionary prisoner dilemma game or be inhibited for an evolutionary snowdrift game.In this work,we investigate cooperation in a population on a square lattice where the interaction among players contains both prisoner dilemma game and snowdrift game.The heterogeneity in interaction is introduced to the population in two different ways:the heterogenous character of interaction assigned to every player(HCP) or the heterogenous character of interaction assigned to every link between any two players(HCL).The resonant enhancement of cooperation in the case of HCP is observed while the resonant inhibition of cooperation in the case of HCL is prominent.The explanations on the enhancement or inhibition of cooperation are presented for these two cases. 相似文献
994.
GU Zhi-Yu QIAN Shang-Wu 《理论物理通讯》2009,51(6):967-972
This paper obtains the knotted pictures of Hadamard gate and CNOT gate in terms of surgical operations described in knot theory. 相似文献
995.
The effect of DziaJoshinski-Moriya (DM) interaction on thermal entanglement of a two-qubit XXZ spin chain in a homogenous magnetic field is investigated. It is found that the DM interaction can enhance thermal entanglement. When D is large enough, the entanglement can exist for larger temperatures and strong magnetic field. 相似文献
996.
In this paper the J/ψ→μ^+μ^- reconstruction performance in the CMS experiment at the LHC is studied in detail by using B8→J/ψφ→μμKK events. The reconstruction efficiencies of J/ψ mesons and their decay muons are obtained as a function of the transverse momentum PT and the pseudo-rapidity η. We also study the muon trigger efficiency for this channel with the planned Level-1 trigger and High Level Trigger selection criteria. It was observed that the muon reconstruction efficiency decreases when the two decay muons have a small or large 3D angular separation, which further affects the overall J/ψ reconstruction efficiency. 相似文献
997.
The BESⅢ ·RPC with Gd coating as thermal neutron detector was designed and constructed. Three prototypes were built with different techniques of producing the gadolinium converter. The performance of the cosmic ray test, the signal and the radiation spectrum were discussed in this paper. Lastly, the efficiency of one prototype with the best performance for detecting the thermal neutron was tested as 8.7%. 相似文献
998.
Tunable All-Optical Filtering and Buffering in a Coupled Quantum Dot-Planar Photonic Crystal Structure
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We theoretically investigate controlled tunable all-optical filtering and buffering of optical pulses in a hybrid nano-photonic structure, where a single quantum dot (QD) embedded in a photonic crystal nanocavity is sidecoupled between a bare nanocavity and a photonic crystal waveguide. We demonstrate that there is a sharp low-loss transmission peak in the transmission spectrum under even low QD-nanocavity coupling strength and the input optical pulses can be delayed up to several hundred picoseconds within the dephasing time of the QD. The filtering regime can be shifted readily by manipulating the detuning between the QD excitonic transition frequency and resonant frequency of the nanocavity mode, which can be explored in future for on-chip all-optical logic and signal processing. 相似文献
999.
1000.
一锅法合成甲基丙烯酰基封端的PLA-PEG-PLA大分子单体 总被引:2,自引:0,他引:2
以辛酸亚锡[Sn(Oct)2]为催化剂、聚乙二醇为引发剂引发丙交酯开环聚合,用水终止反应后再加入甲基丙烯酸酐反应即可得到甲基丙烯酰基封端的PLA-PEG-PLA大分子单体。上述两步反应可一锅进行,操作简便、收率高。采用GPC、FTIR、^1H-NMR、TG、XRD等分析手段表征了大分子单体的结构和性质。所得大分子单体的水溶液在光引发剂存在下,能被UV引发光聚合形成水凝胶。该水凝胶作为可降解生物材料可用于药物控释栽体和组织工程支架。 相似文献