全文获取类型
收费全文 | 65篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 14篇 |
数学 | 5篇 |
物理学 | 47篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 12篇 |
2012年 | 1篇 |
2011年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有66条查询结果,搜索用时 0 毫秒
41.
In this work we present a numerical code for evaluating the system performances of wavelength division multiplexed (WDM) point-to-point optically amplified links, taking into account the behavior of the erbium amplifier with WDM signals. The code uses a conventional split-step method to evaluate the signal propagation in the optical fiber while the signal at the amplifier output is obtained after having evaluated the gain and amplified spontaneous emission noise contribution by finding the evolution of the excited ion fraction along the doped fiber. As an example, we study a 16 x 2.5 Gbit/s system operating in a link 1000 km long with an amplifier spacing of 100 km. 相似文献
42.
Francesco Matera Francesca Matteotti Paolo Pasquali Luca Rea Giorgio Tosi-Beleffi Alessandro Tarantino Vittorio Baroncini Giuseppe Del Prete Giancarlo Gaudino 《Fiber and Integrated Optics》2006,25(3):245-255
The introduction of intelligence for management and control of optical networks based on internet protocol and the quality of service (QoS) are key issues for the evolution of the next generation network. In this paper the authors report experimental results on QoS measurements related to different real time multimedia services in an optical network based on a ring configuration obtained by means of the fibers contained in an installed cable between Rome and Pomezia, core routers with optical Gigabit Ethernet interfaces and configured with differentiated service over multi-protocol label switching architecture. 相似文献
43.
44.
Bank Bernd Giusti Marc Heintz Joos Lecerf Grégoire Matera Guillermo Solernó Pablo 《Foundations of Computational Mathematics》2015,15(1):159-184
Foundations of Computational Mathematics - Let $$V$$ be a smooth, equidimensional, quasi-affine variety of dimension $$r$$ over $$mathbb {C}$$ , and let $$F$$ be a $$(ptimes s)$$ matrix of... 相似文献
45.
46.
Efficient frequency conversion of the XeF excimer (351.2 nm) by nonlinear effects in a highly multimode silica fiber is reported. Besides a substantial Raman amplification of the weaker XeF line at 353.3 nm, stimulated four-photon mixing has also been observed, generating a Stokes peak at 355.5 nm with 1 kW peak power. 相似文献
47.
Bazzicalupi C Biagini S Bencini A Faggi E Giorgi C Matera I Valtancoli B 《Chemical communications (Cambridge, England)》2006,(39):4087-4089
A new polyammonium receptor is able to selectively recognise and sense ATP among triphosphate nucleotides, thanks to ATP-induced quantitative quenching of its fluorescence emission. 相似文献
48.
Hakim Meskine Sebastian Matera Matthias Scheffler Karsten Reuter Horia Metiu 《Surface science》2009,603(10-12):1724-1730
The conceptual idea of degree of rate control (DRC) approaches is to identify the “rate limiting step” in a complex reaction network by evaluating how the overall rate of product formation changes when a small change is made in one of the kinetic parameters. We examine two definitions of this concept by applying it to first-principles kinetic Monte Carlo simulations of the CO oxidation at RuO2(1 1 0). Instead of studying experimental data we examine simulations, because in them we know the surface structure, reaction mechanism, the rate constants, the coverage of the surface and the turn-over frequency at steady-state. We can test whether the insights provided by the DRC are in agreement with the results of the simulations thus avoiding the uncertainties inherent in a comparison with experiment. We find that the information provided by using the DRC is non-trivial: It could not have been obtained from the knowledge of the reaction mechanism and of the magnitude of the rate constants alone. For the simulations the DRC provides furthermore guidance as to which aspects of the reaction mechanism should be treated accurately and which can be studied by less accurate and more efficient methods. We therefore conclude that a sensitivity analysis based on the DRC is a useful tool for understanding the propagation of errors from the electronic structure calculations to the statistical simulations in first-principles kinetic Monte Carlo simulations. 相似文献
49.
50.
Clelia Dallanoce Giovanni Grazioso Diego Yuri Pomè Miriam Sciaccaluga Carlo Matera Cecilia Gotti Sergio Fucile Marco De Amici 《Journal of computer-aided molecular design》2013,27(11):975-987
The binding mode of nicotinic agonists has been thoroughly investigated in the last decades. It is now accepted that the charged amino group is bound by a cation-π interaction to a conserved tryptophan residue, and that the aromatic moiety is projected into a hydrophobic pocket deeply located inside the binding cleft. A hydrogen bond donor/acceptor, maybe a water molecule solvating this receptor subsite, contributes to further stabilize the nicotinic ligands. The position of this water molecule has been established by several X-ray structures of the acetylcholine-binding protein. In this study, we computationally analyzed the role of this water molecule as a putative hydrogen bond donor/acceptor moiety in the agonist binding site of the three most relevant heteromeric (α4β2, α3β4) and homomeric (α7) neuronal nicotinic acetylcholine receptor (nAChR) subtypes. Our theoretical investigation made use of epibatidine 1 and deschloroepibatidine 2 as molecular probes, and was then extended to their analogues 3 and 4, which were subsequently synthesized and tested at the three target receptor subtypes. Although the pharmacological data for the new ligands 3 and 4 indicated a reduction of the affinity at the studied nAChRs with respect to reference agonists, a variation of the selectivity profile was clearly evidenced. 相似文献