全文获取类型
收费全文 | 10759篇 |
免费 | 2035篇 |
国内免费 | 2748篇 |
专业分类
化学 | 8093篇 |
晶体学 | 385篇 |
力学 | 720篇 |
综合类 | 249篇 |
数学 | 1312篇 |
物理学 | 4783篇 |
出版年
2024年 | 30篇 |
2023年 | 210篇 |
2022年 | 428篇 |
2021年 | 470篇 |
2020年 | 532篇 |
2019年 | 509篇 |
2018年 | 439篇 |
2017年 | 521篇 |
2016年 | 539篇 |
2015年 | 610篇 |
2014年 | 755篇 |
2013年 | 926篇 |
2012年 | 988篇 |
2011年 | 989篇 |
2010年 | 857篇 |
2009年 | 890篇 |
2008年 | 877篇 |
2007年 | 814篇 |
2006年 | 710篇 |
2005年 | 578篇 |
2004年 | 459篇 |
2003年 | 337篇 |
2002年 | 354篇 |
2001年 | 341篇 |
2000年 | 343篇 |
1999年 | 227篇 |
1998年 | 117篇 |
1997年 | 73篇 |
1996年 | 89篇 |
1995年 | 57篇 |
1994年 | 72篇 |
1993年 | 51篇 |
1992年 | 43篇 |
1991年 | 44篇 |
1990年 | 46篇 |
1989年 | 35篇 |
1988年 | 25篇 |
1987年 | 32篇 |
1986年 | 19篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1974年 | 5篇 |
1959年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Entanglement Purification for Mixed Entangled Quantum Dot States via Superconducing Transmission Line Resonators
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)
An entanglement purification protocol for mixed entangled states is presented via double quantum dot molecules inside a superconducing transmission line resonator (TLR). In the current scenario, coupling for arbitrary double quantum dot molecules can be tuned via the TLR in the large detuning region by controlling the qubit level splitting. The TLR is always empty and only virtually excited, so the interaction is insensitive to both the TLR decay and thermal field. Discussion about the feasibility of our scheme shows that the entanglement purification can be implemented with high fidelity and successful probability. 相似文献
982.
This paper intends to provide an overview for using corannulene derivatives in organic electronics such as organic field-effect transistors (OFETs), organic solar cells (OSCs), and organic light-emitting diodes (OLEDs). We highlight the rational design strategies, tuning molecular orbital energy levels and arrangement in single crystals of corannulenes. The topological structure and properties of corannulene make it a unique candidate for organic electronics. 相似文献
983.
984.
Zhou Yan Yang Zhao-hui Huang Jing Xu Rui Song Pei-pei Zhang Yi-jie Li Juan Aloun Manosane 《Research on Chemical Intermediates》2017,43(7):3939-3959
Research on Chemical Intermediates - Generally, most biomaterials present high biosorption capacity for heavy-metal ions. In this study, alkaline reagents and microbial flocculant GA1 (MBFGA1) were... 相似文献
985.
Performance of gain-switched all-solid-state quasi-continuous-wave tunable Ti:sapphire laser system
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We have made a gain-switched all-solid-state quasi-continuous-wave (QCW) tunable Ti:sapphire laser system, which is pumped by a 532 nm intracavity frequency-doubled Nd:YAG laser. Based on the theory of gain-switching and the study on the influencing factors of the output pulse width, an effective method for obtaining high power and narrow pulse width output is proposed. Through deliberately designing the pump source and the resonator of the Ti:sapphire laser, when the repetition rate is 6 kHz and the length of the cavity is 220 mm, at an incident pump power of 22 W, the tunable Ti:sapphire laser from 700 to 950nm can be achieved. It has a maximum average output power of 5.6W at 800nm and the pulse width of 13.2 ns, giving an optical conversion efficiency of 25.5% from the 532 mn pump laser to the Ti:sapphire laser. 相似文献
986.
Kulbaba K Cheng A Bartole A Greenberg S Resendes R Coombs N Safa-Sefat A Greedan JE Stöver HD Ozin GA Manners I 《Journal of the American Chemical Society》2002,124(42):12522-12534
Pt(0)-catalyzed ring-opening precipitation copolymerization of [1]silaferrocenophanes fcSiMe(2) (3) and the spirocyclic cross-linker fcSi(CH(2))(3) (4) (fc = Fe(eta(5)-C(5)H(4))(2)) was used to prepare polyferrocenylsilane microspheres (PFSMSs) under mild conditions. By varying the reaction conditions, a wide variety of other morphologies was obtained. The effects of temperature, monomer ratio, solvent composition, catalyst concentration, and time on the observed morphology were investigated and interpreted in terms of a mechanism for microsphere formation. The most well-defined particles were formed using equimolar amounts of 3 and 4, in a 50:50 mixture of xylenes and decane at 60 degrees C with gentle agitation. Chemical oxidation of the polymeric microspheres led to positively charged particles (OPFSMSs) which underwent electrostatically driven self-assembly with negatively charged silica microspheres to form core-corona composite particles. Redox titration with controlled amounts of the one-electron oxidant [N(C(6)H(4)Br-p)(3)][PF(6)] in acetonitrile led to the oxidation of the outer 0.15 microm (ca. 32%) of the PFSMSs. The resulting OPFSMSs were reduced back to their neutral form by reaction with hydrazine in methanol. Pyrolysis of the PFSMSs led to spherical magnetic ceramic replicas with tunable magnetic properties that organize into ordered 2-D arrays at the air-water interface under the influence of a magnetic field. 相似文献
987.
988.
989.
REN Ping-Da PAN Shi-Feng DONG Ting-Wei WU Shi-HuiDepartment of Chemistry Pudan University Shanghai China 《中国化学》1996,14(5):462-466
In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresponding homoallylic alcohols were obtained in excellent yields with high chemo-and stereoselectivity. 相似文献
990.
XIANG Shiqing LOU Qihong DONG Jingxing MANG Yanping WEI Yunrong 《Chinese Journal of Lasers》1996,5(5):385-390
Generationof2-10nsExcimerLaserPulsebyOpticalSynchronizingWave-clippingXIANGShiqing;LOUQihong;DONGJingxing;MANGYanping;WEIYunr... 相似文献