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51.
Diode laser extended cavity for broad-range fast ramping 总被引:1,自引:0,他引:1
A novel design for an extended-cavity diode laser is presented. The cavity contains an electro-optic prism for synchronous tuning of the cavity length and the grating's incident angle. A simple analysis of the cavity is presented. Experimental results are reported that show mode-hop-free tuning over more than 10 GHz with high linearity and reproducibility. To the authors' knowledge, this is the first demonstration of mode-hop-free tuning of an extended cavity over several free spectral intervals with an electro-optic crystal. 相似文献
52.
Shuzheng Yang Qingquan Jiang Huiling Li 《International Journal of Theoretical Physics》2007,46(3):625-636
The strictly thermal spectrum in dragging coordinate system and the tunneling radiation characteristics of stationary axisymmetry
Kerr-Newman de Sitter black hole is studied. The result shows that the tunneling rates at the event and cosmological horizon
are related to the change of Bekenstein-Hawking entropy and that the factual radiation spectrum is not strictly pure thermal.
Thus an exact correction to the Hawking thermal spectrum is present. 相似文献
53.
Classic molecular dynamics (MD) calculations were performed to investigate the deposition of thin hydrocarbon film. SiC (1 0 0) surfaces were bombarded with energetic CH3 molecules at impact energies ranging from 50 to 150 eV. The simulated results show that the deposition yield of H atoms decreases with increasing incident energy, which is in good agreement with experiments. During the initial stages, with breaking Si-C bonds in SiC by CH3 impacting, H atoms preferentially reacts with resulting Si to form Si-H bond. The C/H ratio in the grown films increases with increasing incident energy. In the grown films, CH species are dominant. For 50 eV, H-Csp3 bond is dominant. With increasing energy to 200 eV, the atomic density of H-Csp2 bond increases. 相似文献
54.
Molecular dynamics simulations of the CH3 interaction with Si(1 0 0) were performed using the Tersoff-Brenner potential. The H/C ratio obtained from the simulations is in agreement with available experimental data. The results show that H atoms preferentially react with Si. SiH is the dominant form of SiHx generated. The amount of hydrogen that reacts with silicon is essentially energy-independent. H atoms do not react with adsorbed carbon atoms. The presence of C-H bonds on the surface is due to molecular adsorption. 相似文献
55.
金属氢的高压合成机理 总被引:4,自引:1,他引:3
从氢原子间及氢分子间的相互作用入手,提出了固体氢中氢分子在高压作用下解离为氢原子,并以氢原子相互结合成金属氢的微观转化过程的机理。用这样的转化机理,可以解释毛河光等关于固体氢的拉曼光谱频率随高压变化规律的实验结果。 相似文献
56.
为了更进一步了解CFB气化能力和碳利用率,本文报道了两种煤焦(西山焦煤飞灰,神木煤)以二氧化碳及氧气混合物为气化介质,在小型鼓泡流化床上进行气化反应的研究,并与相同气化条件下的循环流化床气化数据进行了比较。研究结果表明:在相同直径气化反应装置上,相同的气化条件下,循环流化床(CFB)的气化碳转化率、气化强度远远高于鼓泡流化床(BFB)的气化结果,但BFB的煤气中可燃气组成高于CFB的。CFB气化反应装置更适合于生产中、低热值煤气。 相似文献
57.
Peng‐Fei Gou Wei‐Pu Zhu Ning Zhu Zhi‐Quan Shen 《Journal of polymer science. Part A, Polymer chemistry》2009,47(11):2905-2916
Novel amphiphilic eight‐arm star triblock copolymers, star poly(ε‐caprolactone)‐block‐poly(acrylic acid)‐block‐poly(ε‐caprolactone)s (SPCL‐PAA‐PCL) with resorcinarene as core moiety were prepared by combination of ROP, ATRP, and “click” reaction strategy. First, the hydroxyl end groups of the predefined eight‐arm SPCLs synthesized by ROP were converted to 2‐bromoesters which permitted ATRP of tert‐butyl acrylate (tBA) to form star diblock copolymers: SPCL‐PtBA. Next, the bromide end groups of SPCL‐PtBA were quantitatively converted to terminal azides by NaN3, which were combined with presynthesized alkyne‐terminated poly(ε‐caprolactone) (A‐PCL) in the presence of Cu(I)/N,N,N′,N″,N″‐pentamethyldiethylenetriamine in DMF to give the star triblock copolymers: SPCL‐PtBA‐PCL. 1H NMR, FTIR, and SEC analyses confirmed the expected star triblock architecture. The hydrolysis of tert‐butyl ester groups of the poly(tert‐butyl acrylate) blocks gave the amphiphilic star triblock copolymers: SPCL‐PAA‐PCL. These amphiphilic star triblock copolymers could self‐assemble into spherical micelles in aqueous solution with the particle size ranging from 20 to 60 nm. Their micellization behaviors were characterized by dynamic light scattering and transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2905–2916, 2009 相似文献
58.
59.
Dy3+-doped SrB4O7 phosphors were synthesized by solid-state reaction. The luminescence properties of white-light SrB4O7:Dy3+ under vacuum ultraviolet (VUV) excitation were firstly investigated. According to strong absorption around 147 nm in excitation spectra, energy can easily be transferred to the energy levels of Dy3+ from host absorption, and hence luminescence of SrB4O7:Dy3+ under VUV excitation was effective, and it has the potential of being applied to a white lamp-house for mercury-free lamp. 相似文献
60.