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991.
More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T(7) and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider. 相似文献
992.
Zhanwei Xu Huijuan Luo Huihui Sun Qinglin Zhang Gaoxiang Cao Kezhi Li 《Solid State Communications》2011,151(8):643-646
Graphite nanosheets (GNs) doped with N, Fe, or Ni were synthesized by pyrolysis of metal tetrapyridinoporphyrazine (MPTpz, M=Fe2+, and Ni2+) and a mixture of MPTpzs in a chemical vapor deposition furnace. The products obtained were characterized by scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. The magnetic properties of the GNs obtained were investigated at room temperature using a vibrating sample magnetometer with an applied field of −10 000-10 000 Gs. The results show the GNs obtained are terrace-like and ultra-thin, with very high aspect ratio. Fe, Ni and N atoms have been doped to the GNs successfully. There are two types of N atom that are introduced into pure carbon systems: pyrinidic and graphitic N atoms. The GNs obtained exhibit ferromagnetic behavior at room temperature. Sample S1, obtained by pyrolysis of a mixture of MPTpzs (M=Fe2+ and Ni2+), have the highest coercivity force. The saturation magnetization (Ms), remanent magnetization (Mr), and coercivity (Hc) values of sample S1 are 24.51 emu g−1, 3.95 emu g−1, and 207.34 Gs, respectively. 相似文献
993.
Limited-projection fluorescence molecular tomography (FMT) can greatly reduce the acquisition time, which is suitable for resolving fast biology processes in vivo but suffers from severe ill-posedness because of the reconstruction using only limited projections. To overcome the severe ill-posedness, we report a reconstruction method based on the projected restarted conjugate gradient normal residual. The reconstruction results of two phantom experiments demonstrate that the proposed method is feasible for limited-projection FMT. 相似文献
994.
We present what we believe to be the first results that obtained with the recursive least square zonal slope predictor working on an open-loop liquid-crystal adaptive optics system operating on astronomical implementation at visible and near infrared wavelength on a 1.23 m telescope. The system produces substantially better results than a direct open-loop correction based on previous measurement. A 27% relative gain in full-width at half-maximum and 30% relative gain in Strehl ratio are obtained. 相似文献
995.
Zemin WangYu Cao Xiangyou LiMing Gao Xiaoyan Zeng 《Optics and Lasers in Engineering》2011,49(7):880-884
A novel and cheap direct writing method based on the micropen has been developed to fabricate fluorinated polyimide stripe optical waveguides on Si/SiO2 wafers. The overall design, starting material, micropen direct writing system and fabrication processes of the stripe optical waveguides are presented. The effects of the key direct writing parameters, such as the tip-to-substrate distance, extrusive gas pressure, writing speed and viscosity of the polyamic acid, on the dimension and morphology of the stripe optical waveguides are discussed in detail. After deposition by the micropen system and baking process, the fluorinated polyimide stripe optical waveguides with good morphology and surface quality can be fabricated using the optimal parameters. The propagation losses at the wavelength of 1.55 μm are in the range of 1.4-3.5 dB cm−1 as characterized by different length combinations of the strip optical waveguides. 相似文献
996.
We present a extended-cavity diode laser (ECDL) with kilohertz linewidth by optical feedback from a monolithic folded Fabry-Perot cavity (MFC). In our experiments, an MFC replaces the retroreflecting mirror in the traditional ECDL configuration. Beat-note measurements between this MFC-ECDL and a narrow-linewidth reference laser are performed and demonstrate that the linewidth of this MFC-ECDL is about 6.8 kHz. Phase locking of this MFC-ECDL to the reference laser is achieved with a unity gain as small as 10.2 kHz. 相似文献
997.
Investigation on a new electrospun gel polymer electrolyte consisting of thermoplastic polyurethane (TPU) and poly(vinylidene fluoride) (PVdF) has been made. Its characteristics were investigated by scanning electron microscopy, FT-IR, Differential Scanning Calorimeter (DSC) analysis. This kind of gel polymer electrolyte had a high ionic conductivity about 3.2 × 10− 3 S cm− 1 at room temperature, and exhibited a high electrochemical stability up to 5.0 V versus Li+/Li, good mechanical strength and stability to allow safe operation in rechargeable lithium-ion polymer batteries. A Li/GPE/LiFePO4 cell delivered a high discharge capacity when it was evaluated at 0.1 °C—rate at 25 °C (167.8 mAh g− 1). And a very stable cycle performance also existed under this low current density. 相似文献
998.
A novel room temperature solid-state chemical synthesis was introduced to successfully fabricate CeO2 samples, coupled by a polyethylene glycol 400 (PEG 400)/cetyl trimethylammonium bromide (CTAB)/sodium dodecyl sulfate (SDS). The as-prepared products were characterized by XRD, TEM, SEM, BET and UV. A study of photocatalytic degradation of the methylene blue MB under UV illumination has been carried out. It is indicated that the samples exhibit excellent photocatalytic activity. Besides, the samples assisted with surfactants possess higher photocatalytic activity than the sample without any surfactants, wherein the sample with SDS as an additive shows the highest photocatalytic activity, which is able to reach 89.6% MB degradation ratio within 60 min illumination. Moreover, the effects of important operational parameters such as initial MB concentration, catalyst loading and pH were also investigated. The above sample under the optimum conditions obtained the maximum MB degradation ratio up to 96.5%, which is higher than that of the commercial TiO2 P25 under the same conditions. It can be concluded that CeO2 will be a potential photocatalyst in the application of organic pollutant. 相似文献
999.
Xia Liu Hang Song Guoqing MiaoHong Jiang Lianzhen Cao Dabing LiXiaojuan Sun Yiren Chen 《Applied Surface Science》2011,257(6):1996-1999
In0.82Ga0.18As epilayers were grown on InP substrates using a two-step growth technique by LP-MOCVD. A homogeneous low-temperature (450 °C) In0.82Ga0.18As buffer layer was introduced to improve the crystalline quality of epilayers. The influence of low-temperature buffer layer deposition condition, such as thermal annealing duration, on the crystalline quality of the In0.82Ga0.18As epilayer was investigated. Double-crystal X-ray diffraction measurement, Hall measurement, and Raman scattering spectrum were used to evaluate the In0.82Ga0.18As epilayers. Atomic force microscope was used to study the surface morphology. It is found that the In0.82Ga0.18As epilayer, with buffer layer thermal annealing for 5 min, exhibits the best crystalline quality. The change of the surface morphology of the buffer layer after thermal annealing treatment was suggested to explain the phenomenon. 相似文献
1000.
Lihui SunHongwei Qin Feng GaoEnsi Cao Kai FanJifan Hu 《Applied Surface Science》2011,257(7):2633-2636
The adsorption of CO, NH3 and O2 gas molecules on Fe site of La0.875Sr0.125FeO3 (0 1 0) surface has been investigated based on the density functional theory (DFT) with the spin polarized generalized gradient approximation (GGA). The optimal adsorption orientations as well as the adsorption energies for these molecules adsorption on Fe site of La0.875Sr0.125FeO3 (0 1 0) surface are derived. Results show that adsorption configurations with C-down for CO, N-down for NH3 are stable. For the O2 molecule adsorption, the mode with an angle about 120° between the oxygen molecule and La0.875Sr0.125FeO3 (0 1 0) surface is stable. 相似文献