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1.
R. A. Ganeev A. I. Ryasnyanskii M. K. Kodirov Sh. R. Kamalov V. A. Li R. I. Tugushev T. Usmanov 《Technical Physics》2002,47(8):991-995
Nonlinear optical parameters (nonlinear refractive indices and nonlinear absorption coefficients) of solutions of polyvinylpyrrolidone doped by cobalt to various concentrations are measured at the lasing and second-harmonic wavelengths of a picosecond Nd:YAG laser (λ=1064 and 532 nm, respectively, and τ=35 ps). Data on optical limitation in these solutions are presented. The absence of nonlinear absorption in the IR spectral range and its significant effect in the visible range are demonstrated. Optical limitation at a wavelength of 1064 nm is related to defocusing, whereas at 532 nm, this effect is caused by two-photon absorption and partially by inverse saturated absorption and defocusing. Nonlinear optical parameters of metal-polymer complexes are reported. 相似文献
2.
I. A. Begishev R. A. Ganeev V. V. Gorbushin A. A. Gulamov Sh. R. Kamalov T. Usmanov 《Journal of Applied Spectroscopy》1989,51(5):1218-1221
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 5, pp. 867–870, November, 1989. 相似文献
3.
From a fraction of the bases ofColchicium kesselringii Rgl., growing in the Tashkent Province, a new compound which has been called isoregelinone has been isolated. On the basis of spectral characteristics, especially the INDOR spectrum, and chemical transformations, a structure epimeric with that of regelinone has been proposed for it.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 195–199, March–April, 1981. 相似文献
4.
In addition to known ecdysteroids (2-deoxy--ecdysone and 2-deoxyecdysterone) fromSilene praemixta (Caryophyllaceae) we have isolated new ones — premixisterone and selenosterone (I), C27H42O7, mp 115–117°C (from MeOH), []
D
28
+86.9 ± 2° (c 0.92, MeOH), yield 0.003%. The acetylation of (I) with (CH3CO)2O in Py gave 22-acetyl-selenosterone (II), C29H44O6, mp 210–212°C (MeOH-C6H14), []
D
27
+45.5 ± 3° (c 0.16; MeOH). On the basis of physiocochemical and spectral characteristics it has been established that (I) has the structure of 14,22R,25-trihydroxy-5-cholest-7-ene-3,6-dione. The IR, PMR, and mass spectra of (I) and (II) are presented.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 793–797, November–December, 1979. 相似文献
5.
6.
R. Kh. Amirov N. A. Vorona A. V. Gavrikov G. D. Liziakin V. P. Polistchook I. S. Samoylov V. P. Smirnov R. A. Usmanov I. M. Yartsev 《Physics of Atomic Nuclei》2015,78(14):1631-1634
One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics. 相似文献
7.
8.
R.A. Ganeev A.I. Ryasnyansky A.L. Stepanov T Usmanov 《Optical and Quantum Electronics》2004,36(10):949-960
The nonlinear optical characteristics of silicate glasses doped with silver nanoparticles are investigated by Z-scan technique using second harmonic radiation of picosecond Nd:YAG laser (=532 nm, =55 ps). The real and imaginary parts of third-order nonlinear susceptibility of silver-contained glasses were measured. It was found that the sign of Im
(3)was negative due to saturated absorption and the sign of Re
(3) was changed from negative (self-defocusing) to positive (self-focusing) with growth of laser radiation intensity. The mechanisms responsible for saturated absorption and nonlinear refraction are discussed. 相似文献
9.
We report for the first time to our knowledge on the preparation of colloidal solution of chalcogenide semiconductor As2S3 by laser ablation and the measurements of its nonlinear-optical characteristics using Z-scan method at the wavelength of Nd:YAG laser radiation ( = 1064 nm, = 25 ns). The nonlinear refractive index was measured to be –7.5 × 10–18 m2 W–1. Nonlinear absorption coefficient of chalcogenide solution was measured to be 1 cm GW–1. 相似文献
10.
R. A. Ganeev A. I. Ryasnyanskii A. L. Stepanov T. Usmanov 《Physics of the Solid State》2003,45(7):1355-1359
The nonlinear absorption in copper nanoparticles contained in glass matrices is investigated using the Z-scan technique at the wavelength of a picosecond Nd: YAG laser (λ=1064 nm). The experimental data obtained for copper nanoparticle-containing composites synthesized through ion implantation are analyzed. It is demonstrated for the first time that, upon exposure to laser radiation at frequencies outside the range of surface plasma resonance, the nonlinear absorption in metallic particles can be caused by the two-photon effect. The optical limiting due to two-photon absorption is discussed for composites containing copper particles. 相似文献