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951.
Xiaoli Li Guangmin Wu Jun Shen Fan Yang Jue Wang 《Journal of Sol-Gel Science and Technology》2002,25(3):235-242
When designing a cut-off interference filter, extra layers are needed to add on each side of periodic symmetrical multilayer to match the incident medium and the substrate. In this paper, we use sol-gel film with adjustable refractive index as the match layer. The influence of the refractive index and thickness of the match layer on the film system is discussed in detail. As an example, a special filter which is transparent (>80%) at the wavelength 3–5 m and high reflective (>90%) at the wavelength 1.3 m is designed. Finally a series of optimized film parameters are presented. The whole design process is a good reference to the other multilayer special filter made by sol-gel process. 相似文献
952.
Pasa-Tolić L Lipton MS Masselon CD Anderson GA Shen Y Tolić N Smith RD 《Journal of mass spectrometry : JMS》2002,37(12):1185-1198
In the era of systems biology, computational and high-throughput experimental biological approaches are increasingly being combined to provide global snapshots of entire genomes and proteomes under tissue- and disease-specific conditions. The aim is to identify proteins changing in concentration and/or post-translational state and/or location, and develop a better molecular level understanding of the operation of biological systems. Here we describe an approach for comparative proteomics that builds upon the combination of high-performance nano-scale separations with the high-mass measurement accuracy, mass-resolving power and sensitivity of Fourier transform ion cyclotron resonance mass spectrometry to provide broad dynamic range, comprehensive and quantitative proteome measurements. 相似文献
953.
The first synthesis of functionalized gem-difluoroallenes 4 served as platform for an unprecedented molybdenum-catalyzed intramolecular allene-alkyne [2 + 2]-cycloaddition that produced 6, a hitherto unknown class of bicyclo- and heterobicyclo-CF2-containing cyclobutenes. 相似文献
954.
Bogdanov PV Lanzara A Zhou XJ Yang WL Eisaki H Hussain Z Shen ZX 《Physical review letters》2002,89(16):167002
The question of the anisotropy of the electron scattering in high temperature superconductors is investigated using high resolution angle-resolved photoemission data from Pb-doped Bi2Sr2CaCu2O8 (Bi2212) with suppressed superstructure. The scattering rate of low energy electrons along two bilayer-split pieces of the Fermi surface is measured (via the quasiparticle peak width), and no increase of scattering towards the antinode (pi,0) region is observed, contradicting the expectation from Q=(pi,pi) scattering. The results put a limit on the effects of Q=(pi,pi) scattering on the electronic structure of this overdoped superconductor with still very high T(c). 相似文献
955.
Badro J Fiquet G Struzhkin VV Somayazulu M Mao HK Shen G Le Bihan T 《Physical review letters》2002,89(20):205504
We present a new method to separate the crystallographic and electronic phase transitions in hematite using x-ray emission spectroscopy and x-ray diffraction. Our observations, based on the behavior of a metastable high-pressure phase in the stability domain of the low-pressure phase, show that the electronic transition is preempted by the crystallographic transition. The former occurs only afterwards in the high-pressure phase, possibly as a result of a Mott transition. The idea that the electronic transition drives the transition in hematite is therefore invalidated. Such methods should help elucidate the mechanics and the driving forces behind a number of first-order high-pressure phase transitions. 相似文献
956.
Feng DL Damascelli A Shen KM Motoyama N Lu DH Eisaki H Shimizu K Shimoyama Ji JI Kishio K Kaneko N Greven M Gu GD Zhou XJ Kim C Ronning F Armitage NP Shen ZX 《Physical review letters》2002,88(10):107001
The low-energy electronic structure of the nearly optimally doped trilayer cuprate superconductor Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta) is investigated by angle-resolved photoemission spectroscopy. The normal state quasiparticle dispersion and Fermi surface and the superconducting d-wave gap and coherence peak are observed and compared with those of single- and bilayer systems. We find that both the superconducting gap magnitude and the relative coherence-peak intensity scale linearly with T(c) for various optimally doped materials. 相似文献
957.
We report for what is believed to be the first time planar waveguide formation and propagation mode reduction in Nd:YVO(4) crystal, which were achieved by 3.0-MeV silicon-ion implantation followed by annealing under specific conditions. After the implantation, an enhanced refractive-index region was formed with a width of ~2microm beneath the sample surface to act as a waveguide structure. We found that there were four propagation modes for the as-implanted Nd:YVO(4) waveguide, whereas after annealing at 240-360 degrees C for several hours the number of modes could be reduced to three, two, and one. After annealing at 400 degrees C for 1 h the monomode waveguide was destroyed completely, and no mode was observed in the sample. 相似文献
958.
A diffraction theory of continuous-wave photothermal deflection (PD) spectroscopy with fundamental and harmonic responses is presented. The displacement of the probe beam centroid is found to be a rigorous measurement of PD effect, which leads to a set of analytical solutions to the fundamental and the second-order harmonics. Harmonics are caused by the diffraction of the probe beam in the mirage region, which could not be handled by geometric-optics theory. This theory can be used to study bulk materials, thin films, and layered-structure samples. Experimental results are in good agreement with the theory. 相似文献
959.
Poly (3-alkylthiophenes) (P3ATs) have made up of a family of conductive polymerswhich are soluble, fusible and processable, since the introduction of flexible alkyl sidechains"'. It is generally accepted that P3ATs can form similar layered structures. inwhich the thiophene rings possess planarity and the side chains act as spacers'-'. Whenthe number. of 'carbon atoms of alkyl side chains is more than 10, some orderlyarrangements will occur for side chains betWeen the' layers'. It has been w… 相似文献
960.