CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide （FTO） substrate using the hydrothermal and successive ionic layer adsorption and reaction （SILAR） process. The structural and morphological properties of the samples were characterized by X-ray diffraction （XRD）, field-emission scanning electron microscopy （FESEM）, and transmission electron microscopy （TEM）. The results indicate that CdSe/CdS QDs are uniformly coated on the surface of the TiO2 nanorods. The shift of light absorption edge was monitored by taking UV-visible absorption spectra. Compared with the absorption spectra of the TiO2 nanorod array, deposition of CdSe/CdS QDs shifts the absorption edge to the higher wavelength. The enhanced light absorption in the visible-light region of CdSe/CdS/TiO2 nanorod array indicates that CdSe/CdS layers can act as co-sensitizers in quantum dots sensitized solar cells （QDSSCs）. By optimizing the CdSe layer deposition cycles, a photocurrent of 5.78 mA/cm2, an open circuit photovoltage of 0.469 V and a conversion efficiency of 1.34 % were obtained under an illumination of 100 mw/cm2.
Ba0.65Sr0.35TiO3（BST） nanocrystals doped with different concentrations of Er^3＋ ion were fabricated using sol-gel method. The structure and morphology of these BST nanocrystals were studied using X-ray diffraction（XRD）, field emission scanning electron microscopy（FESEM） and transmission electron microscopy（TEM）. The X-ray diffraction patterns of all the nanocrystals prepared in the study correspond to polycrystalline perovskite BST structure. The blue and green upconversion luminescence properties of Er^3＋ doped BST nanocrystals were investigated under excitation by a 785-nm laser. The upconversion emission bands centered at 407, 523, and 547 nm can be attributed to ^2H9/2, ^4I15/2, ^2H11/2, ^4I15/2, and ^4S3/2, 4I15/2 transitions of Er^3＋ ion, respectively. The upconversion mechanism was studied in detail, based on the laser power dependence of the upconverted emissions. In addition, we examined the dependence of the intensity of green upconverted luminescence on the doping concentration of Er^3＋ ions, and discussed the mechanism underlying the process.
研究TD-LTE频段微波介质腔体滤波器的快速设计与调试.为了验证此方法在工程应用领域具有普适性与实用性,利用高频结构仿真软件(HFSS)仿真调试一款8阶准椭圆函数带通滤波器,实现中心频率f0=2 600 MHz,带宽(BW)为40 MHz,插入损耗≤0.5 d B,驻波比≤1.35,带外30 MHz处的抑制≥60 d B.仿真结果达到滤波器商用化的要求,该方法在滤波器设计中具有很大的工程应用价值,可为其他设计者提供参考.
采用传统固相反应法制备x Ca Ti O3-（1-x）La Al O3（0.55≤x≤0.69）（CTLA）陶瓷,研究CTLA陶瓷的物相,微观结构及微波介电性能.结果表明,烧结温度在1 400℃时,陶瓷的微波性能最佳,介电常数在35~47之间,Q×f≥35 000 GHz.随着Ca Ti O3含量的增大,频率温度系数趋零,当x=0.67时,陶瓷具有最佳的微波性能：εr=45,Q×f=36 684 GHz,τf=6.02×10-6/℃.
