共查询到20条相似文献,搜索用时 390 毫秒
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用KTP晶体对激光二极管端面泵浦的Nd∶YAG晶体,Cr∶YAG被动调Q产生的1064 nm脉冲激光器进行腔外倍频,用BBO晶体四倍频产生266 nm紫外激光.用15 W的LD阵列,当LD泵浦功率为12 W的情况下,红外(1064μm)调Q平均输出功率为2.2 W,脉冲序列周期为40μs,脉宽为18 ns,峰值功率高达4.9 kW.采用KTP腔外二倍频,532 nm的绿光输出平均功率为850 mW;用BBO腔外四倍频,266 nm的紫外光输出平均功率高达215 mW,绿光-紫外光光转换效率为25.2%,红外到紫外总的转换效率为9.8%. 相似文献
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LD泵浦Nd:YAG/LBO结构660 nm红光激光器 总被引:3,自引:3,他引:0
采用国产LD泵浦Nd:YAG晶体,通过谐振腔镜的膜系选择获得了Nd3+离子中波长为1319 nm的受激辐射振荡,首次用I类临界位相匹配LBO进行腔内倍频,实现了660 nm红色激光的高效倍频输出.当泵浦注入功率为800 mW时,660 nm激光基横模(TEM00)输出功率为46 mW,光光转换效率高达5.75%. 相似文献
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LD脉冲侧面泵浦Nd∶YAG电光调Q低重频窄脉宽紫外激光器 总被引:1,自引:0,他引:1
介绍了在1~20 Hz电光调Q情况下,半导体脉冲激光侧面泵浦Nd∶YAG晶体腔外四倍频266 nm紫外激光器的输出特性.实验采用直腔结构,在腔外分别利用KTP和BBO晶体产生532 nm倍频绿光、266 nm四倍频紫外激光.当泵浦电流为120 A、重复率为1 Hz时,266 nm紫外激光最大单脉冲能量为15.4 mJ、脉宽8 ns,峰值功率高达1.93 mW;重复率20 Hz时,获得了最大平均功率为156.2 mW的266 nm紫外激光输出,四倍频的转换效率为10.63%.同时利用一组分光镜,获得了352 mW的532 nm脉冲绿光和423 mW的1 064 nm脉冲红外光输出. 相似文献
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Benjamin Grinstein 《Nuclear Physics B》1992,380(3):369-376
The decay constants for D and Ds mesons, denoted fD and fDS respectively, are equal in the SU(3)V limit, as are the hadronic amplitudes for
and
mixing. The leading SU(3)V violating contribution to (FDS/FD) and to the ration of hadronic matrix elements relevant for
and
mixing amplitudes are calculated in chiral perturbatiion theory. We discuss the formalism needed to include both meson and anti-meson fields in the heavy quark effective theory. 相似文献
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N.A. Narasimham K.V.S.R. Apparao T.K. Balasubramanian 《Journal of Molecular Spectroscopy》1976,59(2):244-254
Vibrational and rotational analyses of the near-infrared bands of S2 lying in the region 7440–8085 Å are reported. They form a new band system involving a transition and arise from the same initial 3Πgi state of the 3Πgi-3Δui band system reported earlier. The analyses of the bands of this system due to the isotopic molecules 32S34S and 34S2 are also reported. 相似文献
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Most studies on Co-doped TiO2 system were focused on thin films grown by MBE-based methods. In this work we report the ferromagnetism of nanometer-thick-layered TiO2/Co/TiO2/TiN film grown on Si substrate by conventional magnetron sputtering. For the growth of TiO2 on silicon, a non-oxide thermally stable material, TiN, was introduced to prevent Ti penetration into the Si substrate. Structural, magnetic, and transport measurements respectively by Raman, SQUID and Hall effect show that our samples are n-type semiconductors and exchange bias effect due to exchange coupling between Co and interfacial CoO. For the rapid vacuum annealed specimen, we found an enhanced loss and a Perminvar-type constricted hysteresis loop, which attributed to pinning of domain walls due to an induced anisotropy by the pair ordering in the metallic alloy of Co-Ti-Si. 相似文献
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The branching ratio is calculated for Λ8Li decay to the (2+) 8Be1 states near 17 MeV, using intermediate coupling wave functions for Λ8Li and for the relevant 8Be1 states. It is pointed out that this ratio is sensitive primarily to a mixing angle ? in the Λ8Li wave function. Within one standard deviation, the data allow two ranges (+0.05 to +0.25 rad and +1.10 to +1.25 rad) for the value of ?. The further requirement that there also be acceptable agreement between the angular distribution expected for the subsequent decay and the data, shifts these allowed ranges for ?, to (+0.13 to 0.40) rad and (+0.9 to +1.2) rad. It is predicted that the dominant transition should be to 8Be1 (16.6 MeV), as is observed to be the case, rather than to 8Be1 (16.9 MeV). The interpretation of these values for ? is discussed in some detail and their implications for intermediate coupling shell-model calculations of Λ-hypernuclear wave functions are considered. 相似文献
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The effects of HfOxNy on the electrical property of HfOxNy-HfO2-HfOxNy sandwich-stack (signed as SS) films were investigated. Excellent electrical performances were achieved in SS films, with a high dielectric constant of 16 and a low leakage current of ∼2 × 10−8 A/cm2 at 1 MV/cm. Schottky (SK) emission and Frenkel-Poole (PF) emission are found to be the dominant mechanisms for the current conduction behavior. After a long time stress, the flat-band voltage shift in the SS film is much smaller than that in a pure HfOxNy film indicating fewer charge traps existed in the SS film. Based on the experiments, the new SS structure is more favorable for the improvement of electrical performances than a pure HfOxNy or HfO2 structure. 相似文献
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D. Ziemińska 《Nuclear Physics A》1975,242(3):461-466
The branching ratios are calculated for 11ΛB decay to the 11C ground and excited states below 8 MeV for two possible spin values of 11ΛB. It is found that the decay rate to the 11C★ state at E★ = 6.48 MeV is comparable in magnitude to that leading to the 11C ground state if is assumed. This result, unlike the branching ratios calculated for the case, is in accord with experiment and lends support to the assumption that holds for 11ΛB. The necessity of the reinterpretation of some of the so-called 13ΛC events in terms of is indicated. 相似文献
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N.B. Manson J.T. Gourley E.R. Vance D. Sengupta G. Smith 《Journal of Physics and Chemistry of Solids》1976,37(12):1145-1148
At helium temperatures two sharp lines at 9350 and 9510 cm?1 have been observed for the first tune on the low-energy side of the broad double-peaked absorption corresponding to the transition in Fe2+ at the octahedral site in MgO. The lower energy line has a half width of 4 cm?1; Zeeman measurements show that it is of magnetic dipole origin. The Zeeman spectra are consistent with those expected for a pure electronic transition from the (5T2g)T2g ground state to the 5Eg excited state. The second line, with a halfwidth of ~ 35 cm?1, a vibrational sideband. 相似文献
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We present techniques which enable one to calculate quickly the amplitudes for many scattering processes in the high-energy limit. As an illustration of the method, these are applied to the diagrams for , where V = W± or Z0. The form of the results lends itself to immediate numerical evaluation. 相似文献
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J.L. Soubeyroux J.M. Reau S. Matar G. Villeneuve P. Hagenmuller 《Solid State Ionics》1982,6(1):103-111
Bragg neutron diffraction studies have been carried out on the fluorite type solid solutions K1?xBixF1+2x (0.50 ? × ? 0.70) and Rb1?xBixF1+2x (0.50 ? × ? 0.60). The distribution of the fluorine atoms between normal and interstitial sites is given as a function of substitution rate. A substition mechanism is proposed. Electrical and NMR results on one side and structural data on the other side are correlated. A study of the background as a function of temperature has allowed to determine the static origin of its modulation. By inelastic neutron diffusion, it has been shown that the number of carriers is weak, which involves a high mobility. 相似文献
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N. Mamouni M. Belaiche A. Benyoussef A. El Kenz H. Ez-Zahraouy M. Loulidi E. H. Saidi E. K. Hlil 《中国物理 B》2011,20(8):87504-087504
Electronic and magnetic structures of zinc blende ZnO doped with V impurities are studied by first-principles calculations based on the Korringa-Kohn-Rostoker (KKR) method combined with the coherent potential approximation (CPA).Calculations for the substitution of O by N or P are performed and the magnetic moment is found to be sensitive to the N or P content.Furthermore,the system exhibits a half-metallic band structure accompanied by the broadening of vanadium bands.The mechanism responsible for ferromagnetism is also discussed and the stability of the ferromagnetic state compared with that of the paramagnetic state is systematically investigated by calculating the total energy difference between them by using supercell method. 相似文献