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141.
Tzong-Jer?Yang Yuan-Fong?ChauEmail author Han-Hsuan?Yeh Zheng-Hong?Jiang Yao-Wei?Huang Kuang-Yu?Yang Din?Ping?Tsai 《Applied Physics A: Materials Science & Processing》2011,104(3):857-861
Dispersion properties, birefringence and confinement loss between the circular air-hole photonic crystal fiber (CAHPCF) and
rotational elliptical air-hole photonic crystal fiber (REAHPCF) are investigated numerically by means of a plane-wave expansion
method and a finite element method. Results show that the performances of REAHPCF on flatter dispersion curve, single mode,
high birefringence and low confinement loss is better than that of CAHPCF. 相似文献
142.
New chemometric approaches based on the application of partial least squares (PLS) and principal component regression (PCR) algorithms with fractional wavelet transform (FWT) and continuous wavelet transform (CWT) are proposed for the spectrophotometric multicomponent determination of thiamine hydrochloride (B1), pyridoxine hydrochloride (B6), and lidocaine hydrochloride (LID) in ampules without any separation step. In this study PLS and PCR techniques were applied to the raw spectral data, FWT-coefficients, and FWT-CWT-coefficients. These calibration models were labeled as Raw-PLS and Raw-PCR, FWT-PLS and FWT-PCR, and FWT-CWT-PLS and FWT-CWT-PCR, respectively. A new ultra-performance liquid chromatographic (UPLC) method was developed for the comparison of the results obtained by applying the chemometric calibration methods. Chromatographic separation and determination of B1, B6, and LID in ampules were performed on an Acquity UPLC BEH C18 column (50x2.1 mm id, 1.7 pm particle size) using gradient elution with a mobile phase consisting of methanol and 0.01 M HCI at a constant flow rate of 0.6 mL/min. These combined chemometric calibrations and UPLC were validated by analyzing various ternary mixtures, B1, B6, and LID. The proposed chemometric approaches (signal processing-multivariate calibrations) and UPLC method were applied to the quantitative multicomponent analysis of marketed ampules containing the vitamins B1 and B6 with LID. 相似文献
143.
AC Cruickshank CJ Dotzler S Din S Heutz MF Toney MP Ryan 《Journal of the American Chemical Society》2012,134(35):14302-14305
The structure of copper phthalocyanine (CuPc) thin films (5-100 nm) deposited on single-crystal ZnO(11?00) substrates by organic molecular beam deposition was determined from grazing-incidence X-ray diffraction reciprocal space maps. The crystal structure was identified as the metastable polymorph α-CuPc, but the molecular stacking was found to vary depending on the film thickness: for thin films, a herringbone arrangement was observed, whereas for films thicker than 10 nm, coexistence of both the herringbone and brickstone arrangements was found. We propose a modified structure for the herringbone phase with a larger monoclinic β angle, which leads to intrastack Cu-Cu distances closer to those in the brickstone phase. This structural basis enables an understanding of the functional properties (e.g., light absorption and charge transport) of (opto)electronic devices fabricated from CuPc/ZnO hybrid systems. 相似文献
144.
Reduced surface reflectance and enhanced light trapping is required by any high efficiency solar cell. Anisotropic etching was done on silicon (1 0 0) by using tetramethyl ammonium hydroxide TMAH, (CH3)4NOH, solution at 85 °C. Process variables considered were solution concentration and time proposed by response surface methodology (RSM). An effective surface texture was resulted with reflectance less than 8% without antireflection coating. The antireflection mechanism was also co-related with the etch rate of Si. Optimized values predicted by RSM for time and TMAH concentration were 5 min and 3.50% respectively. The technique and optimization of parameters by using response surface methodology (RSM) could be valuable in the texturization process for high-efficiency Si solar cells. 相似文献
145.
146.
S. M. Idris F. Abdullah M. H. Al-Mansoori M. Z. Jamaludin N. M. Din 《Laser Physics》2010,20(4):855-858
In this paper, we report a fiber laser pressure sensor based on linear cavity erbium-doped fiber laser. The fiber laser structure
comprises of an erbium-doped fiber amplifier, a circulator, an optical coupler and a fiber Bragg grating (FBG) which acts
simultaneously as a lasing wavelength selecting components as well as a pressure sensor. The FBG is fitted to the shock tube
where the pressure is applied. The fiber laser pressure sensor has a low threshold power of 7 mW, an output power of 2.28
mW and an optical signal to noise ratio over 55 dB. The proposed fiber laser sensor is expected to be an attractive choice
for long-distance pressure monitoring. 相似文献
147.
Akmal Khan H.U. Din M. Idrees Fawad Khan Tahani A. Alrebdi Chuong V. Nguyen M. Shafiq B. Amin 《Physics letters. A》2019,383(30):125867
First principles calculations are performed to investigate the structural and electronic properties of MX2 (M = Nb, Pt; X = S, Se) monolayers and their van der Waals (vdW) heterostructures. The dynamical stability of monolayers and vdW heterostructures is confirmed by binding energy and phonon spectra. An indirect band gap nature is found for PtS2 and PtSe2 monolayers while NbS2, NbSe2 and all vdW heterostructures are metals. The intrinsic electronic properties of both NbX2 and PtX2 are well preserved due to weak vdW contact. It is demonstrated that a p-type Schottky contact with a small barrier height is formed at NbX2-PtX2 interface. The zero tunnel barrier and higher potential drop across the interface in these contacts imply large transfer of charge carriers across the interface, making them potential candidates in nanoelectronic device applications. 相似文献
148.
The plasmon and distribution effects of collective localized surface plasmons between incident light and active layer of PtOx-type super resolution near-field structure (super-RENS) have been studied using finite-difference time-domain method. Four types of distribution of Pt nanoparticles, i.e., type A, B, C, and D in active layer are investigated. We find that type C and D in active layer can provide higher field intensity in a wider range of particle size when the particle sizes are varied, and the out-going filed emerging from the active layer exhibit smaller spot size than those of type A and B. Type B, C and D also provide the additional path longer than that of type A, and excite more evanescent field which located in the far edge of the bubble from the optical axis of the incident beam. Results show that the type C structure is the best choice in the view point of designing the PtOx-type super-RENS. This study provides new information to design a super-RENS with superior resolution as well as other applications in nano photonic devices. 相似文献
149.
In this paper we are reporting the interaction of a non-steroidal anti-inflammatory drug ibuprofen (IBF) with various biocompatible polymers. Being amphiphilic, the drug interacts with the polymers similar to the interaction of surfactants and polymers. Therefore, we have considered the polymer-amphiphile interaction approach using conductimetry. The polymers of different charges (cationic, anionic, and nonionic) have been taken for the study. It was found that the critical aggregation concentration (cac) decreases on increasing the polymer concentrations of cationic as well as nonionic polymers whereas it increases for anionic polymers. The results imply that anionic IBF interacts with cationic and nonionic polymers more strongly as compared to the anionic polymers. A possible anionic-anionic repulsion is responsible for the weak interaction of IBF with anionic polymers. On the other side, the critical micelle concentration (cmc) increases for all polymers which is a usual indication of the interaction between amphiphiles and polymers. Free energies of aggregation (ΔGagg) and micellization (ΔGmic) were also computed with the help of degrees of micelle ionization obtained from the specific conductivity - [IBF] isotherms. 相似文献
150.
Roy Chaoming Hsu Din Yuen Chan Cheng-Ting Liu Wei-Chieh Lai 《Multidimensional Systems and Signal Processing》2012,23(4):469-498
In today??s health care, an imaging system plays an important role throughout the entire clinical process from diagnosis and treatment planning to surgical procedures and follow-up studies of disease. Boundary detection is a technique used to segment an object within a region of interest in the medical image for further clinical applications. Contour extraction is one of the most important boundary detection methods. In this paper, an object contour extraction for gray-level medical images using automatic initial boundary pixel selection and tracing of a segmental contour based on the boundary pixels obtained by the initial boundary pixel selection is proposed. Experimental results on artificial images of convex and deep concave objects, and real CT and MRI images show that, in comparing with other existing methods, a more detailed and accurate contour can be obtained using the proposed object contour extraction method. This has low computational complexity, which will benefit applications to clinical diagnosis, treatment, surgery, and follow up studies. 相似文献