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1.
It is found that the scattering of the fragile nucleus 6Li from 12C
and 16O is unexpectedly transparent.
It is shown that the internal-wave
contribution is significantly large in the scattering,
which suggests that some transparency could persist in the scattering
involving the fragile nucleus 6He. 相似文献
2.
在二级轻气炮上,用高速电子相机扫描照相技术和改进的Mallory实验装置,对z切LiF,Al2O3(蓝宝石)和LiTaO3单晶材料的冲击透光性进行了对比测量,并用黑密度计提取出动态图像定量化的光强对比度变化曲线.结果表明,LiF单晶在102 GPa压强下能够保持长时间的初始透光性不变,与公认的LiF具有优良的高压下透明性的认识一致.LiTaO3单晶在实验压力(139GPa)下变成基本不透明.而Al关键词:
2O3')" href="#">Al2O3
LiF
3')" href="#">LiTaO3
光学透明性 相似文献
3.
Transparent and conductive oxide (TCO) thin films of Li-doped NiO were prepared by combinatorial pulsed laser deposition technique. Composition spread approach was applied to optimize the Li concentration for achieving high conductivity and transparency in the film. Conductivity of the composition spread film was found to increase almost linearly from nearly insulating to as high as 1.41 Ω−1 cm−1 with increasing Li content along a 9 mm long film. Optical transparency was found to decrease in an equal proportion across the 40 nm thick film with a slight shift in the absorption edge. 相似文献
4.
With 800-nm, 120-fs laser pulses, optical nonlinearity has been studied in a series of thin films containing poly(methyl methacrylate) (PMMA), filled with surfactant acetylacetone (Acac) capped TiO2 nanoparticles, which were synthesized by a simple in situ sol-gel/polymerization process, assisted by spin coating and multi-step baking. The resulting nanohybrid thin films have highly optical transparency and demonstrate a unique nonlinear optical (NLO) response. The highest nonlinear refractive index (n2) is observed up to 6.55 × 10−2 cm2 GW−1 in the nanohybrid thin film of 60 wt% Ti(OBu)4 in PMMA, with a negligible two-photon absorption (TPA), as confirmed by the Z-scan technique. The titanium precursor loading combined with the nature of the capping molecules are used to influence the ability of nanoparticles to nonlinear optical response. Indeed, the ligands at the nanoparticles’ surface can not only control the extent of the interaction between the organic molecules and the embedded nanoparticles but also influence the optical nonlinearities of nanoparticles. 相似文献
5.
T. N. Smirnova O. V. Sakhno V. I. Bezrodnyj J. Stumpe 《Applied physics. B, Lasers and optics》2005,80(8):947-951
In this letter we report a simple technique to produce volume holographic gratings based on photopolymerizable composites containing TiO2 nanoparticles. Diffraction gratings with high refractive index modulation amplitude (up to 1.25 × 10−2) have been formed due to the periodic distribution of high refractive index nanoparticles in a low refractive index polymer matrix. The diffraction efficiency increases strongly on increasing the nanoparticle concentration. Taking the mixture with 10 wt.% TiO2 nanoparticles, gratings with high diffraction efficiency, low level of scattering and high transparency in the visible-wavelength range have been obtained. This will ultimately lead to different applications of diffractive optical elements based on nanocomposites. The dependence of the gratings’ diffraction efficiency on the intensity of probe laser pulses at 1064 nm has been explored. It is shown that the nonlinear response of the gratings is attributed mainly to the nonlinear properties of the TiO2 nanoparticles embedded in the polymer matrix. The mechanism of the grating formation and the reasons for the nonlinear behavior of the diffraction efficiency are discussed. 相似文献
6.
7.
M.Y.H. Farag 《The European Physical Journal A - Hadrons and Nuclei》2001,12(4):405-411
Glauber's theory has been adopted to calculate the total heavy-ion reaction cross-sections at high energies. At relatively
low energies, Glauber's total reaction cross-section has been modified in order to take into account the Coulomb field effect
and is called modified Glauber model I. In addition to the Coulomb field effect, the nuclear effect has also been taken into
account in the Glauber model and is called modified Glauber model II. An analytical expression for the transparency function
for heavy-ion reactions, involving the nuclear densities of the colliding ions and the nucleon-nucleon cross- section, has
been obtained within the framework of the modified Glauber models I and II. The transparency and the total reaction cross-sections
of the 12C + 12C collisions are calculated at different bombarding energies. The obtained results are in good agreement with the experimental
data and with previous theoretical calculations.
Received: 26 January 2001 / Accepted: 15 October 2001 相似文献
8.
J. Ryckebusch W. Cosyn B. Van Overmeire C. Martınez 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):585-587
We present a selection of results obtained within the context of a relativistic eikonal model. First, results of relativistic
Glauber calculations for the nuclear transparency extracted from photon-induced pion production are presented. Second, computed
differential cross-sections for the 12
C(p, 2p) are compared to data. 相似文献
9.
S. Tomita J.S. Forster P. Hvelplund A.S. Jensen S.B. Nielsen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,16(1):119-122
We have measured attenuation cross sections and fragmentation cross sections for protonated water clusters H(H2O)n
+ (n = 1 to 100) colliding with noble gas atoms (He and Xe) at a laboratory energy of 50 keV. In collisions with He, a transparency
effect in the attenuation cross section was observed. For the case of fragmentation in collisions with Xe, a strong enhancement
of small clusters was observed which we attribute to multifragmentation.
Received 30 November 2000 相似文献
10.
Slow light supported by electromagnetically induced transparency effect in dispersive medium is extremely susceptible with respect to Doppler detuning.In this paper,the Doppler effect induced by rotating dispersive medium was considered and the effect of the velocity of rotating dispersive medium on the group velocity was studied.Based on a dispersive slow-light medium,a high sensitive optical rotation sensor for measuring absolute rotation is proposed and analysed.The sensitivity of the rotation sensor is the group delay between the counterpropagationed wave packets in the device,and scales directly with square of the group index which can reach 10 2-10 8 orders of magnitude by selecting a proper dispersive medium. 相似文献
11.
Yu. I. Heller 《Optics and Spectroscopy》2006,100(2):277-282
The influence of spectral interference of different nature on resonant Faraday rotation is studied using as examples the effect of electromagnetically induced transparency in pure discrete atomic transitions and the transparency windows of autoionization resonances of gaseous media. A common numerical criterion for a substantial effect of spectral interference and coherence of atomic transitions on magneto-optical phenomena is established. A direct relationship between the polarization ellipse rotation angle of cw monochromatic light and reduction of the light pulse group velocity resulting from a strong frequency dispersion of the resonant refractive index is found. The known experimental data on ultraslow light pulses indicate the possibility of interference enhancement of the Faraday effect by a factor of 106?107. 相似文献
12.
Evaluation of Transmutation of ^137Cs(γ, n) 136Cs Using Ultra-Intense Lasers in Solid Targets
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R. Sadighi-Bonabi O. Kokabee 《中国物理快报》2006,23(6):1434-1436
Relativistic electrons produced in ultra-intense laser-solid interaction generate highly collimated γ-ray beams through Bremsstrahlung that can be used to induce photonuclear reactions. Photonuclear transmutation (of (% n) type) of ^137 Cs, one of the hazardous nuclear wastes with half-life of 30.17 years which cannot be transmuted practically with neutron bombardment due to its very low neutron capture cross section, has been considered. Nuclear activity of produced 136Cs with half-life of 13.16 days has been evaluated analytically using available experimental data. With irradiating a ^137Cs sample by p-polarized laser light of 10^20 Wcm^-2 and the repetition rate of 10Hz for 30min, the activity of 0.24 Bq is obtained. It is found that intensity has a large effect in yield around 10^21 Wcm^-2. For similar laser with intensity of 5 ×10^21 Wcm^-2, the activity increases with a factor of 10^5. 相似文献
13.
Electromagnetically-induced transparency (EIT) in three-level Λ-systems is based on quantum interference effects involving
coherence between the two lower levels, which allow propagation of a resonant probe light beam in the presence of a strong
coupling field. We have observed transparency in ultra-narrow (<10 kHz) windows at the resonant 1.083 μm transition for purely
electronic spins in gaseous 4He* at room temperature. Slow light is an interesting outcome of the EIT phenomenon due to extreme dispersion within the narrow
transparency window. We have obtained group delays of about 4 μs in a 2.5 cm long He* cell. A complete theoretical analysis
explains our observations emphasizing the positive role of collisions. Slow light with 1-GHz Doppler broadening opens the
door to applications of controllable large-bandwidth delays in radars. 相似文献
14.
H.S. Jang 《Optics Communications》2007,278(1):99-103
Transparent conducting indium tin oxide (ITO) thin films were prepared on glass substrates by a magnetron sputter type negative ion source which requires cesium (Cs) vapor injection for surface negative ionization on the ITO target surface. Although the film was prepared at 70 °C, it attained high optical transmittance, 88% and low resistivity, 2.03 × 10−4 Ω cm, at an optimized Cs partial pressure of PCs = 1.7 × 10−3 Pa. The as-deposited ITO films have a poly-crystalline structure with (2 1 1), (2 2 2), (4 0 0), (4 1 1) and (4 4 0) reflections.Also, ITO films prepared at PCs = 1.7 × 10−3 Pa were post-deposition vacuum annealed at 300 °C for 30 min. The films had a resistivity of 1.8 × 10−4 Ω cm and a transparency of 89.2%. The post-deposition vacuum annealed ITO film was used as an anode for a transparent organic light emitting diode (TOLED). A maximum luminance of 19,000 cd/m2 was obtained. 相似文献
15.
N.N. Syrbu V. Dorogan A. Dorogan T. Vieru V.V. Ursaki V.V. Zalamai 《Superlattices and Microstructures》2012
The transparency, reflection and luminescence spectra of In0.3Ga0.7As structures with 8 nm thickness and quantum wells limited by the barrier layer GaAs of a 9 nm (upper layer) and 100 nm (bottom layer) thickness had been studied in the region of photon energy 0.5–1.6 eV. Lines associated with the transitions hh,lh1-e1(1s,2s,3s), hh2,lh2-e2(1s,2s,3s), hh1,lh1-e2(1s) and hh3,lh3-e3(1s) had been revealed in reflection spectra. The shapes of the reflection and transparency lines had been calculated using a single oscillator model of dispersion relations and the Kramers–Kronig integrals. The binding energy of hh,lh1-e1 excitons, the effective mass mhh∗ and mlh∗ and the damping factor for the optical transitions to QW and QD had been determined. The lifetime of charge carriers on quantum dots varies in the range of 0.04–0.1 ps, while the radiative lifetime of excitons in quantum wells in the considered structure is around 2 ps. 相似文献
16.
M. El-Nadi M.S. El-Nagdy A. Abdelsalam E.A. Shaat N. Ali-Mossa Z. Abou-Moussa Kh. Abdel-Waged A. M-Abdalla E. El-Falaky 《The European Physical Journal A - Hadrons and Nuclei》2001,10(2):177-181
Data on the multiplicity of secondaries in central events of 28Si (14.6 AGeV) and 32S (3.7 AGeV) interactions with AgBr emulsion nuclei have been compiled and studied. The dependence of the multiplicities of
the outgoing charged stripping particles on the number of interacting nucleons and therefore on the impact parameter, as indicated
by the target size, and consequently, on the degree of centrality is investigated. The resultant multiplicity distribution
of the produced pions for each studied case is fitted by both Negative Binomial (NB) and Poisson distributions. The NB distribution
is valid for most of the considered cases. The transparency of the target for a projectile was found to become more pronounced
as the incident energy increased.
Received: 20 June 2000 / Accepted: 17 January 2001 相似文献
17.
C. Angelini P. Bagnaia G. Baroni J.H. Bartley G. Bertrand-Coremans V. Bisi A. Breslin E.H.S. Burhop F. Carena R. Casali G. Ciapetti M. Conversi D.H. Davis S. Di Liberto M.L. Ferrer C. Franzinetti D. Gamba G. Wilquet 《Physics letters. [Part B]》1979,84(1):150-155
Two new examples of production by neutrinos and subsequent decay of charged charmed hadrons are reported. Together with two similar events reported previously they show that the lifetime of charged charmed particles is in the neighbourhood of 5 × 10?13 s, as expected from current theoretical models. One of the new events is identified as a baryon λc+ of mass 2.295 ± 0.015 GeV/c2 which undergoes the decay process λc+ → pπ+K? with a proper decay time (7.3 ± 0.1) × 10?13 s. 相似文献
18.
19.
Yu. I. Heller 《Optics and Spectroscopy》2006,101(5):777-790
The influence of spectral interference of various nature on the effects of radiation drag is studied using as examples electromagnetically induced transparency in pure discrete atomic transitions and the transparency windows of autoionization resonances of gaseous media. The analysis is performed using the Maxwell equations and taking into account the equivalence of the corresponding spatial dispersion of a substance and the optical effects caused by uniform motion. The realization conditions of the drag coefficients in the Lorentz and Laub forms are found from the exact dispersion equations obtained. A direct relation between the monochromatic radiation drag coefficient and the decrease in the pulsed radiation group velocity due to high frequency dispersion of the resonant refractive index is found. The known experimental data on ultraslow light pulses indicate the possibility of interference enhancement of the light drag effect by a factor of 106-107. 相似文献
20.
M. Kaskulov E. Hernandez E. Oset 《The European Physical Journal A - Hadrons and Nuclei》2007,31(2):245-254
With the aim of extracting information on the shift of the ω mass in the nuclear medium we analyze data obtained at ELSA from
where claims for evidence of a mass shift of the ω have been made. We develop a Monte Carlo simulation code which takes into
account the possible reactions in the experimental set-up of (γA → π0γX) in the vicinity of the ω production region with subsequent ω → π0γ decay. We compare our results with experiment for the distribution of π0γ invariant masses and conclude that the distribution is compatible with an enlarged ω width of about 90MeV at nuclear-matter
density and no shift in the mass. This change in the width would be compatible with the preliminary results obtained from
the transparency ratio in the A-dependence of ω production. The discrepancy of the present conclusions with former claims of an evidence for a shift of the
ω mass stems from a different choice of background which is discussed in the paper. 相似文献