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151.
Lee CP Lin JC Wang YC Chou CY Yeh MH Vittal R Ho KC 《Physical chemistry chemical physics : PCCP》2011,13(47):20999-21008
Novel sub-micro sized hexagonal clubs of ZnO (HC-ZnO), which are coated as a scattering layer (SL) for the photoanode of a DSSC, are synthesized. X-ray diffraction (XRD) patterns of the ZnO clubs show clear peaks corresponding to wurtzite crystal phase of ZnO. Scanning electron microscopic (SEM) images show that each club has two opposite hexagonal faces (parts) of unequal dimensions. High resolution transmission electron microscopic (HR-TEM) image of a single ZnO club reveals that the ZnO is single crystalline and has wurtzite crystal structure; the image indicates a lattice spacing (d) of 0.26 nm; this is ascribed to the (002) planar spacing of the hexagonal ZnO. A solar-to-electricity conversion efficiency (η) of 3.36% is achieved for the cell with the double layer (DL) film, which is 16% higher than that of the cell with only transparent layer (TL) of commercial ZnO (2.89%) and far higher than that of the cell with SL (0.05%). The η of the cell with the DL (3.36%) could further be improved to 4.28% through the modification of the DL surface with TiO(x). Incident photo-to-current conversion efficiency (IPCE) curves, UV-vis absorption spectra, energy dispersive X-ray (EDX) spectra, and electrochemical impedance spectra (EIS) are also used to substantiate the results. 相似文献
152.
On the Congruences of Some Combinatorial Numbers 总被引:1,自引:0,他引:1
In this paper, we apply Lucas' theorem to evaluate the congruences of several combinatorial numbers, including the central Delannoy numbers and a class of Apéry-like numbers, the numbers of noncrossing connected graphs, the numbers of total edges of all noncrossing connected graphs on n vertices, etc. One of these results verifies a conjecture given by Deutsch and Sagan recently. In the end, we use an automaton to explain the idea of our approach. 相似文献
153.
The title compound (Mr = 373) crystalizes in the othorhombic space group P bna with a = 10.410(2), b = 11.658(4), c = 23.108(3) Å, V = 2804.4 Å Z = 8. The single crystal intensity data were collected using MoK∞ radiation (λ = 0.7093Å) at room temperature. The crystal and molecular structure was solved with the final agreement index R = 0.039 for 1046 observed reflections. The bond lengths N(1)- C(7) and C(7)-C(8) of the title compound are slightly longer than those of 3-substituted sydnone derivatives. This may be attributed to the steric effect arising from the interaction of the phenyl ring and the 4-substituent with the neighboring atoms of sydnone ring. Both the title compound and 4-acetyl-3-(p-tolyl)sydnone have smaller dihedral angles between the sydnone ring and the plane of the sp2 orbital of the double bond of the 4-substituent and both have shorter C(7)-C(9) bond lengths than those of other similar sydnone derivatives. 相似文献
154.
A novel monitoring method for in-service fault indemnification in passive optical networks (PONs) is proposed and demonstrated experimentally. The proposed monitoring technique is based on fiber Bragg grating (FBG) sensors and fiber laser scheme, and a semiconductor optical amplifier (SOA) is used to serve as a gain medium. By detecting the number of the wavelength lasing, the fiber-fault can be monitored without affecting the in-service channels. Moreover, the strain behavior on the FBGs has also been discussed. 相似文献
155.
Ting-Chang Chang Wen-Kuan Yeh Yu-Jane Mei Wen-Chung Tsai Chun-Yen Chang Y. F. Chen 《Optical and Quantum Electronics》1996,28(10):1295-1303
Ordered (Ord-SL) and disordered (Dis-SL) Si-SiGe superlattices are grown using ultrahigh vacuum chemical vapour deposition (UHVCVD). The results of cross-sectional transmission electron microscopy (XTEM) and high-resolution double crystal x-ray diffraction (HRXRD) indicate that high quality Si-SiGe superlattices can be achieved. Well-defined band-edge excitonic luminescence is observed for the Si0.86Ge0.14-Si superlattice. Stronger phosoluminescence (PL) is observed for the Si-SiGe disordered superlattice compared with the corresponding Si-SiGe ordered superlattice. Furthermore, PL peak energy of the Dis-SL shifts to lower value with respect to the peak position of the corresponding Ord-SL. The stronger intensity of the no-phonon (NP) peak and the red shift of the PL peak are possibly a result of two probable mechanisms: (i) the tunnelling effect and (ii) the formation of localized states. 相似文献
156.
Digital shifting photoelasticity with optical enlarged unwrapping technology for local stress measurement 总被引:1,自引:0,他引:1
Xue-Feng Yao Long-Hui Jian Wei Xu Guan-Chang Jin Hsien-Yang Yeh 《Optics & Laser Technology》2005,37(7):582-589
In this paper, photoelasticity combined with phase shifting technology is used to obtain stress distribution within the stress concentration zone. Both the optical enlarged unwrapping technology and the combined path shear difference technology are provided for evaluating the local stress information. By means of a phase shifting photoelastic experiment of a diametric-compressed disc, the stress components surrounding the local loading zone are determined. The results show not only a good improvement compared with conventional photoelastic analysis but also a good agreement with theoretical data. 相似文献
157.
Siao‐Wei Yeh Tzung‐Luen Wu Kung‐Hwa Wei Ya‐Sen Sun Keng S. Liang 《Journal of Polymer Science.Polymer Physics》2005,43(10):1220-1229
Surface‐modified CdS nanoparticles selectively dispersed in hexagonally packed poly(ethylene oxide) (PEO) cylinders of poly(styrene‐b‐ethylene oxide) (PSEO) block copolymers were prepared. The photoluminescence and ultraviolet–visible characteristics of the presynthesized CdS nanoparticles in N,N‐dimethylformamide and in PEO domains of the PSEO block copolymers were determined. Because of strong interactions between the CdS nanoparticles and PEO chains, as shown by Fourier transform infrared spectroscopy, the incorporation of the CdS nanoparticles prevented the PEO cylinders from properly crystallizing; this was confirmed by differential scanning calorimetry and wide‐angle X‐ray diffraction measurements. The intercylinder distance between the swollen and reduced‐crystallinity CdS/PEO cylinders in turn increased, as confirmed by small‐angle X‐ray scattering and transmission electron microscopy. At a high CdS concentration (43 wt % or 8.3 vol % with respect to PEO), however, the hexagonally packed cylindrical nanostructure of the PSEO diblock copolymers was destroyed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1220–1229, 2005 相似文献
158.
159.
A frequency selective coupler which consists of two thin film waveguides imbedded in a periodic medium is studied using the Brillouin diagram. Detailed results for the relative bandwidth and the coupling factor are plotted as a function of normalized frequency for a representative case. 相似文献
160.
Magnetoelastic excitations with a fine structure in the 50kHz range have been observed in the study of the domain wall resonance (DWR) in magnetic garnet thin films. DWR excites standing transverse elastic waves which have a resonance frequency given by , where f is the frequency, n is an integer, v=3.5×105 cm/sec is the transversal velocity of the elastic wave, and d=0.05 cm is thickness of the film/substrate system. A fine structure associated with each of these modes has been identified as due to two dimensional bulk elastic waves by using a set of parallel microstrip lines. The dispersion relation of these elastic waves is ω2=v2(k21+k22), where ω is the radial frequency, k1 and k2 are the wave vectors in the orientation perpendicular and parallel to the sample surface respectively. In the case of k1?k2, , where f0 is the resonance when k2=0. The experimental results are in excellent agreement with this model. A linear dispersion, observed when using a shorted slot-line structure, is understood as the excitation of three dimensional modes due to the complex structure of the slot-line and the sample geometry. 相似文献