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991.
Pt0.5−x Mn0.5+x films were prepared by sputtering deposition of Pt foil and Mn target to study the order-disorder transition from a thermodynamic metastable fcc (A1) phase to L10 phase. Both Differential Scanning Calorimetry and High Temperature X-Ray Diffraction studies showed the phase transformation from fcc to the L10 structure for the Pt0.50Mn0.50 and Pt0.40Mn0.60 samples but along completely different kinetic paths. A composition dependent phase transformation was observed by comprehensive Differential Scanning Calorimetry studies on a series of Pt0.5−x Mn0.5+x samples. The changes of the lattice parameter and the cell volume of L10 Pt0.5−x Mn0.5+x as a function of composition suggest that the anti-site is not the dominant point defect for L10 Pt0.5−x Mn0.5+x .  相似文献   
992.
Multi-mode absorption spectroscopy, MUMAS, has been combined with the techniques of wavelength modulation spectroscopy, WMS, and cavity enhanced absorption spectroscopy, CEAS, to record multiple molecular transitions using a single laser and a single detector. MUMAS signals were recorded using a multi-mode diode laser of the A-band $b^{1}\varSigma _{g}^{+}\leftarrow X^{3}\varSigma _{g}^{-}Multi-mode absorption spectroscopy, MUMAS, has been combined with the techniques of wavelength modulation spectroscopy, WMS, and cavity enhanced absorption spectroscopy, CEAS, to record multiple molecular transitions using a single laser and a single detector. MUMAS signals were recorded using a multi-mode diode laser of the A-band b1\varSigma g+? X3\varSigma g-b^{1}\varSigma _{g}^{+}\leftarrow X^{3}\varSigma _{g}^{-} of molecular oxygen at 760 nm. Direct MUMAS and WMS-MUMAS signals were recorded using a White cell for air and pure oxygen for pressures in the range 0 to 1 bar. CEAS-MUMAS signals were recorded with and without WMS in an open enhancement cavity containing laboratory air. Enhancement of the signal-to-noise ratio has been obtained demonstrating the potential for increased detection sensitivity for gas-sensing applications of MUMAS.  相似文献   
993.
The lowest-energy geometries and electronic-structure properties have been obtained for AlnHn (n=1-10) clusters within the density-functional theory using the generalized gradient approximation for the exchange correlation potential. The resulting geometries show that the hydrogen atoms tend to occupy outside positions and no hollow positions are found. The subunit Aln of AlnHn (n=1-5) have little distortion, in comparison with corresponding pure Aln cluster, whereas the subunit Aln have large distortion from n=6. The stability has been investigated by analyzing the binding energy per atom and the second difference in energy, indicating that Al8H8 exhibit higher stability than others. The bonding property has been analyzed by calculating the Mulliken charges and Al–H distances. The calculated energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO), the vertical ionization potential, and the vertical electron affinity also confirm that Al8H8 is a stable cluster. The density of states (DOS) shows that AlnHn exhibit changes from molecular-like (Al1H1) to band-like structure (Al10H10) as n increases.  相似文献   
994.
93.7 W 1112 nm diode-side-pumped CW Nd:YAG laser   总被引:1,自引:0,他引:1  
We demonstrate a high power continuous wave (CW) infrared laser operated at 1112 nm from a diode side-pumped Nd:YAG crystal with a plano-plano symmetrical resonator. By inserting an etalon, an output power of as high as 93.7 W at 1112 nm was obtained at the pump power of 570 W with conversion efficiency of 16.4%. The beam quality factor of M2 was measured to be about 17. The wavelength tunable performance of the etalon was also analyzed. To the best of our knowledge, it is the highest output power at 1112 nm CW laser based on Nd:YAG crystal.  相似文献   
995.
In the present study, we have successfully set up a novel blue light source with the power density of 9 mW/cm2 and the wavelength of 435.8 nm and then the novel light source was used to investigate the effect of light radiation on curcumin-induced cell death. The cytotoxicity was investigated 24 h after the treatment of curcumin and blue light radiation together using MTT reduction assay. Nuclear chromatin was observed using a fluorescent microscopy with Hoechst33258 staining. The results showed blue light radiation could significantly enhance the cytotoxicity of curcumin on the MCF-7 cells and apoptosis induction. These findings demonstrated that blue light radiation could enhance curcumin-induced cell death of breast cancer cells, suggesting light radiation may be an efficient enhancer of curcumin in the management of breast cancer.  相似文献   
996.
This paper presents a brief historical overview of studies of cosmic rays in the Earth’s atmosphere, which were initiated and led by S.N. Vernov for over 50 years. The main results of these studies that were obtained in recent decades are given. They include the study of the processes of generation and propagation of solar cosmic rays, the modulation of galactic cosmic rays in the heliomagnetosphere, and the role of cosmic rays in atmospheric processes.  相似文献   
997.
The authors theoretically demonstrate the terahertz beam shaping with metallic subwavelength holes array surrounded by concentric periodic grooves. High transmission and directional radiation can be obtained simultaneously for the resonant excitation of the surface wave in the combined structure. Finite-difference time-domain simulation results shows that the transmission mainly depends on the lattice constant of hole array and the features of incident surface around it, while the far-field angle distribution is dominated by the details of the output surface. This compact beam shaping structure is hoped to serve as a basic device for future terahertz systems.  相似文献   
998.
We report soft X-ray total ion yield and angular-resolved ion yield spectra of CF3I in the C 1s, I 3d and F 1s ionisation regions, and tentatively assign the observed electronic states. Anisotropy in ion yield is observed only for the C transition, indicating that the dipole moment for this transition is parallel to the C3v. The effusive source of CF3I is heated to 800 K to produce a mixture of CF3 and I, and the resulting spectra are compared to those recorded at room temperature.  相似文献   
999.
Lin ST  Lin YY  Huang YC  Chiang AC  Shy JT 《Optics letters》2008,33(20):2338-2340
We report the observation of thermal-induced optical guiding and bistability in a mid-IR cw, singly resonant optical parametric oscillator (SRO) at approximately 3.2 microm. The SRO employs a MgO:PPLN crystal as the gain medium and a 1-nm-linewidth Yb-fiber laser at 1.064 microm as the pump source. As soon as the pump power reaches the thermal guiding threshold at 16.5 W, the SRO shows a step increase in the parametric efficiency by a factor of 2.5. At 25 W pump power, the SRO generated 5.3 and 1.2 W at 1.58 and 3.23 microm, respectively, with single-longitudinal-mode performance for the 3.23 microm radiation.  相似文献   
1000.
Cu-CeO2 catalysts deposited on a commercial ZrO2 support have been investigated. The catalyst composition has been optimized: the optimum copper content was found to be 5–10 wt % at a cerium oxide content of 23 wt %. The catalysts were investigated by X-ray diffraction analysis and X-ray photoelectron spectroscopy. According to the X-ray diffraction data, the support consists of the monoclinic ZrO2 phase and cubic CeO2 phase with an enlarged lattice parameter, while the catalysts contain CuO. The X-ray photoelectron data indicate the presence of a highly dispersed CuO2 phase interacting with cerium oxide and zirconia on the surface of the catalyst having the optimum copper content.  相似文献   
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