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991.
M. Teresa Barros M. Adilia Januário Charmier Christopher D. Maycock Thierry Michaud 《Tetrahedron》2005,61(33):7960-7966
Several optically active mono and diaminopolyols have been synthesized starting from the octadienedioate 1, by regio- and stereo selective azidation of the corresponding alcohol by Mitsunobu/SN2 substitution. 相似文献
992.
D. Shafer 《Optics & Laser Technology》1982,14(1):37-38
A simple laser beam expander is described which possesses several attractive features: there are only two optical elements; it is unobscured; it covers a wide spectral range with excellent performance; it can be made for any particular expansion ratio; and one of the two elements can usually be bought as an ‘off-the-shelf’ item. 相似文献
993.
Careful design of mounting structures and drive-circuit parameters is essential to obtain very short pulse-lengths with high peak powers from semiconductor diode lasers. We have developed a diode laser model using a coupled rate equation approach to predict operating regimes producing ultrashort output pulses. The model has been refined through comparison with experiment, and a 10 ps source, designed on the basis of this model, has been implemented. 相似文献
994.
C. Gastaud M. Redon P. Belland M. Fourrier 《International Journal of Infrared and Millimeter Waves》1984,5(6):875-885
This paper reports the first use of a N2O laser for optically pumping vinyl halides, to obtain new cw submillimeter laser lines. Eighteen far-infrared (FIR) emissions have been observed in vinyl chloride, twenty five in vinyl bromide and thirty eight in vinyl flouride. 相似文献
995.
Excitation and decay rates of the 4880 Å-ArII-laser transition pumped in a low-pressure arc yield a power limit for ArII high power lasers (arc diameter >1 cm), caused mainly by radiation trapping. Maximum power of the 4880 Å laser is Φ/L=70W/m±25%. 相似文献
996.
M. Feny 《Optics & Laser Technology》1984,16(4):209-215
A physical model is described to explain the biostimulating effect of a laser beam. It is proposed that polarization is responsible, with the unidirectional electromagnetic field reorienting the lipid bilayer in the cell membrane. A light source which emits linearly polarized light has been made and used in clinical trials. 相似文献
997.
Luo Xizhang Zou Joujia Qiu Bingshen Lin Yikun 《International Journal of Infrared and Millimeter Waves》1989,10(2):237-249
A very short OPFIR superradiant laser was studied theoretically and experimentally. The density matrix equations of a three-level quantum system for NH3 gas was solved for the gains of the FIR signal and the IR signal in the very short OPFIRL system. The output characteristics of the OPFIR superradiant laser were calculated numercally. A curve showing the relation between the length of the sampe tube of the OFFIRL and the corresponding optimum pressure was obtained. In our experiment, a 10cm OPFIRL and a 5cm OPFIRL were constructed and operated successfully. The output characteristics were meassured and the calculated results were verified. 相似文献
998.
F. Francini 《Optics & Laser Technology》1983,15(6):307-310
A new method for measuring the magnitude and direction of the velocity of a diffuse object is proposed. The method is based on the Doppler effect using the virtual shift of a pair of photodetectors placed on a plane in the far-field of the speckle pattern. 相似文献
999.
J. H. Bellina 《Optics & Laser Technology》1982,14(2):105-106
Laser tubal microsurgery was carried out on a sample of 82 patients. Employing current laser surgical systems, 21 conceptions occured in 20 patients, after limited exposure to conception risk during the 13-month study. This represents 48% of the 42 patients at risk. Tubal patency was demonstrated in 94% of the 82 cases. Based upon experience to date, more conceptions are expected as more patients become at risk and as exposure increases. 相似文献
1000.
Xiao Huang Yanxiang Bao Jiaying Qin Xingshi Zheng Xizhang Luo 《International Journal of Infrared and Millimeter Waves》1998,19(12):1711-1720
Using the CH3OH molecular energy levels data base management program, we deduced that when a CH3OH laser pumped by CO2-9P(16) line, there should be a FIR laser line of 918m wavelength, which corresponding to a transition in ground-state reversed three-level energy system. For the first time, the spectra of ground-state reversed three-level system transitions were calculated by solving the density matrix equations, and the spectrum characteristics of 918m line were studied. Experimentally, the CH3OH FIR laser line of 918m wavelength was obtained by pumping with a TEA-CO2 laser. The experimental results were in good agreement with the theoretical calculations. 相似文献