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张道中 《光谱学与光谱分析》2003,23(6):1238-1238,1202,1220
张志三,光谱学家。《光谱学与光谱分析》的副主编、顾问。早期致力于原子发射光谱应用的研究。建立较完善的分子光谱实验室,为我国光谱学的发展做出了贡献。热心进行激光光谱的应用研究,促进了我国激光物理,原子、分子物理的发展。张志三先生因病于2003年9月20日在北京逝世,享年83岁。张先生严以律己,宽厚待人,治学严谨的科学态度,深得科技界同行的爱戴和赞誉。得知张先生过世的消息,大家深为悲痛。张志三先生的生前好友于9月25日到医院向张先生作最后告别。 相似文献
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引 言 科学的光谱学真正开始在瑞典的Uppsala,1853年A.Angstrom在那里获得了一个放电火花隙的某些谱线,它们分别来源于金属电极及电极之间的气体.J.Fraunhofer在此之前就记录了太阳光谱的暗线并测量了它们的波长.但是,Angstrom首先证认了其中一些谱线相应于火花隙中特殊物质所辐射的亮线.更重要的是,他得到了氢的红线,即Hα线.在以后的几年里,Angstrom在氢里又发现了几条可见区域的谱线并精确地测量了它们的波长.W.Huggins和H.W.Vogel在1880年成功地拍摄了恒星的光谱.他们发现这些可见区的谱线是一个扩展到紫外区域的更长的系列的一部… 相似文献
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张志三先生是光谱学家，早期致力于原子发射光谱应用的研究，建立了较完善的分子光谱实验室，为我国光谱学的发展做出了贡献，他热心进行激光光谱的应用研究，促进了我国激光物理、原子、分子物理的发展，张志三先生因病于2003年9月20日在北京逝世，为表达我们的哀思和怀念，特转载张道中研究员撰写的《张志三先生的生平和科学贡献(1920—2003年)》一文。 相似文献
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In the calibration of the optical trap stiffness, it is found that there appears an attenuating oscillation as an oscillatory disturbance added to the trapped bead movement, when the scanner is driven by a triangular wave input.An equivalent oscillator model is put forward to explain the mechanism of the oscillatory disturbance. Both the measurements and calculations show that the attenuating oscillation comes from the oscillation of the scanner and the triangular wave drive causes this additional oscillation of the scanner. Furthermore, the analysis indicates that the oscillatory disturbance will become stronger, when the stiffness of the trap increases or the natural frequency of the scanner decreases. We adopt another driving way, i.e. a sinusoidal wave input is used instead of the triangular wave input. Our experiment has verified that in this case the oscillatory disturbance is eliminated completely. 相似文献
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Negative Refraction and Near-Field Imaging of an Elliptical-Rod Photonic Crystal Slab in the Second Band 
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下载免费PDF全文 Negative refraction and imaging properties of the electromagnetic wave through a two-dimensional photonic crystal （PC） slab, which consists of a square lattice of elliptical dielectric rods immersed in the air background, is studied by the plane-wave expansion method and the finite-difference time-domain method. A point source placed in the vicinity of the PC slab can form a good-quality image spot through the PC slab for the incident frequencies within the second photonic band. The calculated result also shows that negative refraction occurs in this kind of PC slab. 相似文献
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A highly efficient W3 Y-branch filter in a two-dimensional photonic crystal slab with triangular lattice of air holes is designed and fabricated, and its transmission properties are measured. By accurately adjusting the size of the resonant cavities, the minimum wavelength spacing of 7 nm between two channels is realized. The corresponding resonant wavelengths of the two cavities agree well with the calculated ones. This implies that this kind of fiIter may be promising in integrated wavelength division multiplexing system. 相似文献
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Effect of the defect on the focusing in a two-dimensional photonic-crystal-based flat lens 下载免费PDF全文
下载免费PDF全文 We have investigated in detail the influence of defect on the focusing of electromagnetic waves in a two-dimensional photonic-crystal flat lens by using the finite-difference time-domain method. The result shows that many focusings can be observed at the symmetrical positions when a defect is introduced into the lens. Furthermore, the wave-guides in the lens can confine the transmission wave effectively and improve the quality of the focusing. 相似文献
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Trapping force was calculated with a homogeneous dielectric sphere model. Results indicate that the transverse trapping force of optical tweezers can be increased effectively through modifying laser beam profile while the axial stability of the system is still assured. This is quite important when optical tweezers are applied to the precise measurements for single biological molecule. 相似文献
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