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991.
采用溶剂热法制备氨基功能化Fe_3O_4磁性材料(NH_2@nFe_3O_4),通过浸渍法将磺化酞菁铝(AlPcS)负载于NH_2@nFe_3O_4。材料的傅立叶红外、漫反射、X射线衍射、扫描电镜、透射电镜、振动磁强计等表征表明:AlPcS主要通过静电作用与NH_2@nFe_3O_4结合,AlPcS-NH_2@nFe_3O_4平均粒径为127 nm,饱和磁化强度为75.3 emu·g-1。在可见光和空气作用下,该功能化磁性材料对降解弱碱性水溶液中环境内分泌干扰物双酚A(BPA)具有较高的光敏化活性。随着AlPcS负载量的增加活性呈先升高后下降的趋势,负载量为3.4%(质量分数)的复合材料性能最佳,反应60 min后,20.0 mg·L-1BPA降解率为96%;循环使用10次,BPA降解率仍保持93%以上。通过NaN3猝灭实验探讨了反应机理,证实1O2是光敏化过程中的主要活性物种。 相似文献
992.
研究了三(三甲基硅烷)亚磷酸酯(TMSP)添加剂对高镍三元正极材料Li Ni_(0.83)Mn_(0.05)Co_(0.12)O_2(LNMC811)高电压循环性能的影响。结合电化学表征、理论计算、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)等方法研究发现,在高电位(4.5 Vvs Li/Li~+)下,TMSP添加剂能够在LNMC811正极表面被氧化分解,生成一层富含导锂离子性能好的硅酸盐和电化学稳定的无机碳酸锂,且电解液主要分解产物(有机碳酸锂和氟化锂)含量较少的正极固体电解质界面(CEI)膜;分析表明覆盖在正极表面的薄而均匀的CEI膜,能够很好的降低充放电过程的极化电压,隔离电解液和正极的接触,减少电解液的分解,抑制金属离子的溶出,稳定正极晶体结构,使LNMC811材料能够在4.5 V(vs Li/Li~+)高电压循环时仍然保持良好的循环性能和倍率性能。 相似文献
993.
994.
Tlie rational designs of particle size, morphology and surface states of the Au nanoparticles(AuNPs) are crucial for Au nanocatalyst. We herein report a method to synthesize the silica microspheres supported AuNPs(ca.1 nm) and their application in controlling the reaction conversion and selectivity in styrene epoxidation. Surfactant-ftee AuNPs deposited on silica microspheres were in situ fabricated with aid of the Ag nanoparticles (AgNPs) as sacrificial template by galvanic replacement reaction, leading to AuNPs/SiO2 catalyst directly without any post-treatment to expose crystal facets.A high conversion of 46.7% and selectivity of 91.7% to styrene oxide was achieved with H2O2 as oxidant in ethanol. The solid catalyst could be reused at least 10 reaction cycles without significant decrease in activity and selectivity. This study not only supplies an active, recoverable catalyst for styrene oxidation with green oxidant and solvent, but also demonstrates that the silica microspheres functionalized with thiol groups have a superior ability in stabilizing noble metal nanoparticles even without any surfactant. 相似文献
995.
We demonstrate a new approach, i.e., a cw dual-frequency Brillouin fiber laser pumped by two independent single-frequency Er-doped fiber lasers, for the generation of tunable low-noise rf/microwave optical signals. Its inherent features of both linewidth narrowing effect in a Brillouin fiber cavity and common mode noise cancellation between two laser modes sharing a common cavity allow us to achieve high frequency stability without using a supercavity. Beat frequency of the dual-frequency Brillouin fiber laser can be tuned from tens of megahertz up to 100 GHz by thermally tuning the wavelengths of the two pump lasers with tuning sensitivity of approximately 1.4 GHz/ degrees C. Allan variance measurements show the beat signals have the hertz-level frequency stability. 相似文献
996.
997.
YU Shao-Ying LI Yan-Xia SHEN Cai-Wan 《理论物理通讯》2008,50(8):459-462
The two-dimensional total routhian surface calculations have been carried out to stud), the triaxial superdeformed structure of a neutron-rich nucleus ^173 Hf firstly. In particular the effects of the rotational frequency ω and pairing-energy gap parameter A are discussed in detail in the course of shaping its triaxial superdeformation; additionally the neutron-shell correction energy is analyzed with emphasis in the confirmed triaxial superdeformed nucleus ^173Hf. Finally, more systematical results have been investigated for some confirmed superdeformed nuclei experimentally and a few predicted triaxial superdeformed nuclei theoretically with quadropole deformation ε2 ≈0.4 and triaxial deformation γ≈20° or 30° in the Z = 72 region. 相似文献
998.
YIN Miao CHENG Ze SHEN Lei-Lei 《理论物理通讯》2008,50(9):661-663
We investigate the generation of entanglement of coherent excitonic states in coupled quantum dots placed in a cavity by meaning of the state preparation fidelity [Nature (London) 404 (2002) 256; Phys. Rev. A 65 (2002) 012107; J. Uffink, Phys. Rev. Lett. 88 (2002) 230406.] The effect of the number of excitons and the coherent intensity |α| of the cavity field on the entanglement is also studied. 相似文献
999.
Formation Mechanisms of Electrical Conductivity and Optical Properties of ZnO:N Film Produced by Annealing Treatment
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WANG Xiang-Hu YAO Bin WEI Zhi-Peng SHEN De-Zhen ZHANG Zhen-Zhong LU You-Ming ZHANG Ji-Ying FAN Xi-Wu 《中国物理快报》2008,25(8):2993-2996
The effects of annealing on the chemical states of N dopant, electrical, and optical properties of N-doped ZnO film grown by molecular beam epitaxy (MBE) are investigated. Both the as-grown ZnO:N film and the film annealed in N2 are of n-type conductivity, whereas the conductivity converts into p-type conductivity for the film annealed in O2. We suggest that the transformation of conductivity is ascribed to the change in ratio of the N molecular number on O site (N2)O to the N atom number on O site (NO) in ZnO:N films under the various annealed atmosphere. For the ZnO:N film annealed in N2, the percentage content of (N2)O is larger than that of NO, i.e.the ratio >1, resulting in the n-type conductivity. However, in the case of the ZnO:N film annealed in O2, the percentage content of (N2)O is fewer than that of NO, i.e., the ratio <1, giving rise to the p-type conductivity. There is an obvious difference between low-temperature (80K) PL spectra of ZnO:N film annealed in N2 and that of ZnO:N film annealed in O2. An emission band located at 3.358eV is observed in the spectra of the ZnO:N film after annealed in N2, this emission band is due to donor-bound exciton (D0X). After annealed in O2, the PL of the donor-bound exciton disappeared, an emission band located at 3.348eV is observed, this emission band is assigned to acceptor-bound exciton (A0X). 相似文献
1000.
The synchronization and pattern dynamics of coupled logistic maps on a certain type of complex network, constructed by adding random shortcuts to a regular ring, is investigated. For parameters where an isolated map is fully chaotic, the defect turbulence, which is dominant in the regular network, can be tamed into ordered periodic patterns or synchronized chaotic states when random shortcuts are added, and the patterns formed on the complex network can be grouped into two or three branches depending on the coupling strength. 相似文献