36 resultados para 1056
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
The close form solutions of deflections and curvatures for a film–substrate composite structure with the presence of gradient stress are derived. With the definition of more precise kinematic assumption, the effect of axial loading due to residual gradient stress is incorporated in the governing equation. The curvature of film–substrate with the presence of gradient stress is shown to be nonuniform when the axial loading is nonzero. When the axial loading is zero, the curvature expressions of some structures derived in this paper recover the previous ones which assume the uniform curvature. Because residual gradient stress results in both moment and axial loading inside the film–substrate composite structure, measuring both the deflection and curvature is proposed as a safe way to uniquely determine the residual stress state inside a film–substrate composite structure with the presence of gradient stress.
Resumo:
本文通过模拟计算和对比分析了一个气动激光器的多种腔体内三维辐射场的分布、饱和增益分布、输出功率和效率,具体地显示出沿流动方向折叠腔的优越性.其基本规律也可供其他高速流动气动激光器作参考.
Resumo:
The fluorescence emission from indole resulting from two-color two-photon (2C2P) excitation with 400 and 800 nm wavelengths is observed, using the second harmonic and fundamental wavelength of a 800 nm 40 fs pulsed Ti:Sapphire femtosecond (fs) regenerative amplifier operating at a repetition rate of 1 kHz. By delaying one fs laser pulse relative to the other, the cross correlation of fluorescence is observed, which indicates the generation of 2C2P fluorescence signal in the experiment. The strongest 2C2P fluorescence emission characterized by the peak of cross correlation curve suggests optimal temporal overlap of the two fs laser pulses. The 2C2P fluorescence signal is linearly dependent on the total excitation intensity. The fluorescence signals with 400 nm and 800 nm irradiation alone are also demonstrated and discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
We present a simple route for ZnSe nanowire growth in the ablation crater on a ZnSe crystal surface. The crystal wafer, which was horizontally dipped in pure water, was irradiated by femtosecond laser pulses. No furnace, vacuum chamber or any metal catalyst were used in this experiment. The size of the nanowires is about 1-3 mu m long and 50-150 nm in diameter. The growth rate is 1-3 mu m/s, which is much higher than that achieved with molecular-beam epitaxy and chemical vapor deposition methods. Our discovery reveals a rapid and simple way to grow nanowires on designed micro-patterns, which may have potential applications in microscopic optoelectronics. (C) 2007 Elsevier Ltd. All rights reserved.
Resumo:
采用AgNO3、KNO3混和熔盐作为离子交换源,在K9玻璃上制备了跑道形谐振腔滤波器。测试得到该滤波器的自由光谱范围为0.178nm,两个输出端口的衬比度分别为1.47dB和6.5dB,分析得到耦合器的分束比和谐振腔的传输损耗分别为κ=0.16和α=8.1dB/cm。利用热光效应在16℃的温度变化范围内,滤波器实现了2π的相位调制,同时分析得到波导材料的热光系数约为1.28×10^-5/℃。
Resumo:
It is shown that stochastic electromagnetic beams may have different degrees of polarization on propagation, even though they have the same coherence properties in the source plane. This fact is due to a possible difference in the anisotropy of the field in the source plane. The result is illustrated by some examples.
Resumo:
先天性小眼球是一种先天发育异常性眼科疾病.通过基因扫描和连锁分析对一个6代常染色体显性遗传先天性小眼球中国家系的疾病相关基因进行研究.根据已报道的与小眼球相关的5个基因座位(MITF,SOX2,PAX6,MCOP和NNO2),在3,11,14和15号染色体上选取了14个微卫星标记,以荧光标记引物的聚合酶链反应(PCR)扩增目的片段,用ABI 377 DNA遗传分析仪对该家系成员进行基因扫描和基因分型,并采用Linkage软件包对基因分型结果进行连锁分析.结果显示,该家系致病基因与这些已报道的座位均不连锁,即该家系致病基因不是已报道的座位,可能是一个尚未报道的对眼球发育至关重要的新基因座位.
Resumo:
Investigation of an organic extract of Schisandra rubriflora led to the isolation of three new highly oxygenated nortriterpenoids, named rubriflorins A-C (1-3), together with six related known compounds (4-9). Their structures were elucidated by spectrosc
Resumo:
研究了烧结厂烟道烟尘和静电除尘器灰尘中二噁英的浓度和分布特征.结果显示,烧结台车机头烟道烟尘和机尾烟道烟尘中二噁英的总含量分别为867.49±215.41和170.35±51.12pg.Nm-3,毒性当量分别36.53±4.47和9.13±2.40pgWHO-TEQ.Nm-3;机头静电除尘器灰尘和机尾静电除尘器灰尘的总含量分别为2423.59±100.01和157.29±36.83pg.g-1dw,毒性当量分别71.67±0.62和7.50±1.08pgWHO-TEQ.g-1dw.烧结中二噁英的分布以PC
Resumo:
A broadband external cavity tunable laser is realized by using a broad-emitting spectral InAs/GaAs quantum dot (QD) gain device. A tuning range of 69 nm with a central wavelength of 1056 nm, is achieved at a bias of 1.25 kA/cm(2) only by utilizing the light emission from the ground state of QDs. This large tunable range only covers the QD ground-state emission and is related to the inhomogeneous size distribution of QDs. No excited state contributes to the tuning bandwidth. The application of the QD gain device to the external cavity tunable laser shows its immense potential in broadening the tuning bandwidth. By the external cavity feedback, the threshold current density can be reduced remarkably compared with the free-running QD gain device.