全文获取类型
收费全文 | 54篇 |
免费 | 5篇 |
专业分类
化学 | 39篇 |
数学 | 5篇 |
物理学 | 15篇 |
出版年
2017年 | 1篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有59条查询结果,搜索用时 15 毫秒
11.
光学特异材料的设计 总被引:2,自引:0,他引:2
Christian Helgert Thomas Pertsch Carsten Rockstuhl Ekaterina PshenaySeverin Christoph Menzel ErnstBernhard Kleyet.al 《中国光学》2010,3(1):1-10
In this contribution we review our latest achievements of combined experimental and theoretical studies to tailor the properties of optical metamaterials(MMs) at will. We give three examples of metamaterial designs that have been realized by means of electron-beam lithography and whose spectroscopic characteristics have been comprehensively investigated. In every case, our experiments are complemented by rigorous numer ical simulations. Particular emphasis is put on the significance of such tailored effective properties of optical MMs 相似文献
12.
J. K. Brooks Kazuyuki Saitô JD Maitland Wright 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):5-14
LetA be aC*-algebra with second dualA″. Let (φ
n)(n=1,...) be a sequence in the dual ofA such that limφ
n(a) exists for eacha εA. In general, this does not imply that limφ
n(x) exists for eachx εA″. But if limφ
n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ
n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for
positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem. 相似文献
13.
14.
The exploitation of microdroplets produced within microfluidic environments has recently emerged as a new and exciting technological platform for applications within the chemical and biological sciences. Interest in microfluidic systems has been stimulated by a range of fundamental features that accompany system miniaturization. Such features include the ability to process and handle small volumes of fluid, improved analytical performance when compared to macroscale analogues, reduced instrumental footprints, low unit cost, facile integration of functional components and the exploitation of atypical fluid dynamics to control molecules in both time and space. Moreover, microfluidic systems that generate and utilize a stream of sub-nanolitre droplets dispersed within an immiscible continuous phase have the added advantage of allowing ultra-high throughput experimentation and being able to mimic conditions similar to that of a single cell (in terms of volume, pH, and salt concentration) thereby compartmentalizing biological and chemical reactions. This review provides an overview of methods for generating, controlling and manipulating droplets. Furthermore, we discuss key fields of use in which such systems may make a significant impact, with particular emphasis on novel applications in the biological and physical sciences. 相似文献
15.
Weisser F Huebner R Schweinfurth D Sarkar B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(20):5727-5736
Reactions of [{Ru(tmpa)}2(μ‐Cl)2][ClO4]2, ( 2 [ClO4]2, tmpa=tris(2‐pyridylmethyl)amine) with 2,5‐dihydroxy‐1,4‐benzoquinone ( L1 ), 2,5‐di‐[2,6‐(dimethyl)‐anilino]‐1,4‐benzoquinone ( L2 ), or 2,5‐di‐[2,4,6‐(trimethyl)‐anilino)]‐1,4‐benzoquinone ( L3 ) in the presence of a base led to the formation of the dinuclear complexes [{Ru(tmpa)}2(μ‐ L1 ?2 H)][ClO4]2 ( 3 [ClO4]2), [{Ru(tmpa)}2(μ‐ L2 ?2 H)][ClO4]2 ( 4 [ClO4]2), and [{Ru(tmpa)}2(μ‐ L3 ?2 H)][ClO4]2 ( 5 [ClO4]2). Structural characterization of 5 [ClO4]2 showed the localization of the double bonds within the quinonoid ring and a twisting of the mesityl substituents with respect to the quinonoid plane. Cyclic voltammetry of the complexes show two reversible oxidation and quinonoid‐based reduction processes. Results obtained from UV/Vis/NIR and EPR spectroelectrochemistry are invoked to discuss ruthenium‐ versus quinonoid‐ligand‐centered redox activity. The complex 3 [ClO4]2 is compared to the reported complex [{Ru(bpy)}2(μ‐ L1 ?2 H)]2+ ( 12+ , bpy=2,2′‐bipyridine). The effects of substituting the bidentate and better π‐accepting bpy co‐ligands with tetradentate tmpa ligands [pure σ‐donating (amine) as well as σ‐donating and π‐accepting (pyridines)] on the redox and electronic properties of the complexes are discussed. Comparisons are also made between complexes containing the dianionic forms of the all‐oxygen‐donating L1 ligand with the L2 and L3 ligands containing an [O,N,O,N] donor set. The one‐electron oxidized forms of the complexes show absorption in the NIR region. The position as well as the intensity of this band can be tuned by the substituents on the quinonoid bridge. In addition, this band can be switched on and off by using tunable redox potentials, making such systems attractive candidates for NIR electrochromism. 相似文献
16.
17.
M. Huebner 《Statistical Inference for Stochastic Processes》1999,2(1):57-68
Consider a parabolic stochastic partial differential equation perturbed by small noise observed on a time interval [0,T]. We construct the maximum likelihood estimators of the coefficients of the operators involved in these equations based on partial observations in the form of diffusion processes and show the asymptotic efficiency for loss functions with polynomial majorant as the variance goes to zero. 相似文献
18.
19.
W.F. Huebner M.F. Argo L.D. Ohlsen 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,19(1):93-97
Removal of outer electrons from an atom does not significantly change the potential and wave functions over the region where the wave function of the remaining bound electrons is large. This explains why the partial cross sections of an ion are similar to those of its neutral atom but truncated at the ion's threshold. Scaling by the wave-function-effective-Z can significantly improve the accuracy of the ion partial cross sections. 相似文献
20.