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991.
采用时域法中的时间相关单光子计数方法记录荧光寿命,时间相关单光子计数采用多波长通道同时记录荧光光子数,可以提高计数效率和信息量,还可以在稳态图像中分离不同荧光团,形成4维图像。并采用多光子激发技术,利用长波长光源发出的两个或多个光子可以激发出一个短波长的光子。多个光子必须几乎同时到达激发点,才能提供被激发分子足够的能量以产生荧光。多光子激发波长较长,生物组织对其散射减小,因而可以穿透到更深层的组织,从而提高荧光成像深度和空间分辨力,并减少对活体样品的损伤。 相似文献
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994.
The interaction of in-band and in-gap lattice soliton trains in optically induced two-dimensional photonic lattices 下载免费PDF全文
We demonstrate the coherent interactions of lattice soliton trains,including in-band solitons (IBSs) and gap soliton trains (GSTs),in optically induced two-dimensional photonic lattices with self-defocusing nonlinearity.It is revealed that the π-staggered phase structures of the lattice soliton trains will lead to anomalous interactions.Solely by changing their initial separations,the transition between attractive and repulsive interaction forces or reversion of the energy transfer can be obtained.The 'negative refraction' effect of the soliton trains on the interaction is also discussed.Moreover,two interacting IBSs can merge into one GST when attraction or energy transfer happens. 相似文献
995.
LI ZhiHong SU Jun GUO Bing LI ZhiChang BAI XiXiang LIU JianCheng LI YunJu YAN ShengQuan WANG BaoXiang WANG YouBao LIAN Gang ZENG Sheng LI ErTao CHEN YongShou SHU NengChuan FAN QiWen & LIU WeiPing China Institute of Atomic Energy Beijing China 《中国科学:物理学 力学 天文学(英文版)》2010,(4)
The angular distribution of the 12C(7Li,6He)13N reaction at E(7Li) = 44.0 MeV was measured at the HI-13 tandem accelerator of Beijing, China. The asymptotic normalization coefficient (ANC) of 13N → 12C + p was derived to be (1.64 ± 0.11) fm-1/2 through the distorted wave Born approximation (DWBA) analysis. The ANC was then used to deduce the astrophysical S (E) factors and reaction rates for the 12C(p,γ)13N direct capture reaction at energies of astrophysical relevance. 相似文献
996.
Ya-Lun Tsai Hsiao-Chin Lan Sheng Fu Lin Chia-Chi Chang Hsu-Liang Hsiao Yun-Chih Lee Jenq-Yang Chang Mount-Learn Wu 《Optical Review》2010,17(6):536-540
In this paper, the design of low-loss tapered waveguides by applying photonic-crystal-based microlenses is presented. The
microlenses are realized by using two-dimensional photonic crystal (PhC) structures with a hexagonal periodic lattice of air-holes.
In order to make the PhC structures behave as homogeneous and isotropic microlenses, the PhC structures are designed to operate
in the low-frequency domain with light wavelength sufficiently larger than the PhC lattice constant. The effective indices
of the PhC are calculated and the structures are properly arranged in microlenslike shapes. By monolithically integrating
the effective microlenses in the tapered area between the two optical waveguides with different core dimensions, the wavefront
of the eigenmode can be coupled from the larger core to the smaller core effectively and also the radiation loss in the tapered
area between the two connected optical waveguides can be effectively suppressed. The results show that the PhC-based microlens
in the telescopic structure can serve as an optical element in the tapered waveguide with the advantages of low loss, high
efficiency and compactness. 相似文献
997.
In this paper, ultrasonic irradiation was utilized for improving the corrosion resistance of phosphate coatings on aluminum alloys. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The effect of ultrasonic irradiation on the corrosion resistance of phosphate coatings was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). Various effects of the addition of Nd2O3 in phosphating bath on the performance of the coatings were also investigated. Results show that the composition of phosphate coating were Zn3(PO4)2 · 4H2O(hopeite) and Zn crystals. The phosphate coatings became denser with fewer microscopic holes by utilizing ultrasonic irradiation treatment. The addition of Nd2O3 reduced the crystallinity of the coatings, with the additional result that the crystallites were increasingly nubby and spherical. The corrosion resistance of the coatings was also significantly improved by ultrasonic irradiation treatment; both the anodic and cathodic processes of corrosion taking place on the aluminum alloy substrate were suppressed consequently. In addition, the electrochemical impedance of the coatings was also increased by utilizing ultrasonic irradiation treatment compared with traditional treatment. 相似文献
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999.
The possible geometrical and the electronic structures of small MgnNi(n = 1-7) clusters are optimised by the density functional theory with a LANL2DZ basis set.The binding energy,the energy gap,the electron affinity,the dissociation energy and the second difference in energy are calculated and discussed.The properties of Mg n Ni clusters are also discussed when the number of Mg atom increases. 相似文献
1000.
Baohuai Sheng 《分析论及其应用》2006,22(4):319-328
In the present paper,we provide a way of constructing translation network operators by Bernstein-Durrmeyer operators. 相似文献