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991.
Shuo-Hsien Cheng Shu-Hua Chou Wen-Yi Hung Hong-Wei You You-Ming Chen Atul Chaskar Yi-Hung Liu Ken-Tsung Wong 《Organic Electronics》2013,14(4):1086-1093
A series of new bipolar hosts C1O1, C2O1, and C1O2 comprising hole-transporting carbazole as donor (D) and electron-transporting oxadiazole as acceptor (A) have been designed and synthesized to tune D/A ratio with a view for getting in-depth information about structure–property–performance relationship. The D/A ratio exerts subtle influences on absorption spectra and energy levels. Time-of-flight (TOF) measurements reveal that the increment of donor units effectively increase the hole mobility. The appropriate energy levels and triplet energies along with promising morphological and thermal stability of these molecules bring out them as suitable hosts to realize green PhOLEDs with (PBi)2Ir(acac) and (PPy)2Ir(acac) emitters. Green phosphorescent devices hosted by C1O1, C2O1, and C1O2 achieved maximum external quantum efficiencies of 20.7%, 20.4%, and 17.3%, respectively. These results indicate that carbazole/oxadiazole hybrid molecule with one carbazole and oxadiazole each is a better candidate for highly efficient green PhOLEDs. 相似文献
992.
Abstract Database management has become increasingly important in recent years. How to design an efficient database machine becomes an essential topic. This paper presents a database machine for supporting the primitive operations of a relational algebra. A hash‐sort‐merge strategy has been adopted to implement the join operation. A reconfigurable merger and bi‐directional zero‐time sorter have been employed in the database machine for flexibly sorting and merging various sizes of buckets. We compare the performance of our database machine with that of some other database machines. From our results, when the sizes of operand relations are large, our database machine is superior. 相似文献
993.
To provide the detection of hypoglycemic episodes in Type 1 diabetes mellitus, hypoglycemia detection system is developed by the use of variable translation wavelet neural network (VTWNN) in this paper. A wavelet neural network with variable translation parameter is selected as a suitable classifier because of its excellent characteristics in capturing nonstationary signal analysis and nonlinear function modeling. Due to the variable translation parameters, the network becomes an adaptive network and provides better classification performance. An improved hybrid particle swarm optimization is used to train the parameters of VTWNN. Using the proposed classifier, a sensitivity of 81.40 % and a specificity of 50.91 % were achieved. The comparison results also show that the proposed detection system performs well in terms of good sensitivity and acceptable specificity. 相似文献
994.
Kuang-Teng Hung Hsuan-Ta Wu Sheng-Wen Fu Hui-Ju Chen Chu-Yun Hsiao Chuan-Feng Shih 《Organic Electronics》2013,14(1):182-186
This paper reports on the improvement of the efficiency of organic solar cells (OSCs) by using ion beam-assisted sputtering (IBAS) to synthesize the alumina-doped zinc oxide (AZO) anodes that are used therein. The anode voltage of the ion source and the substrate temperature during IBAS were varied. When the substrate temperature was 460 °C, increasing the anode voltage from 0 to 40 V increased the efficiency of the OSCs by ~50%. The optical, electrical, morphological, and interfacial properties of the AZO and organic layers were investigated. The improvement of OSCs was associated with an increase in the conductivity, FOM, surface work function of the AZO films, and a decrease in the contact resistance in AZO/CuPc interface. 相似文献
995.
996.
Richard P. Gangloff Hung M. Ha James T. Burns John R. Scully 《Metallurgical and Materials Transactions A》2014,45(9):3814-3834
Hydrogen environment-assisted cracking (HEAC) of Monel K-500 is quantified using slow-rising stress intensity loading with electrical potential monitoring of small crack propagation and elastoplastic J-integral analysis. For this loading, with concurrent crack tip plastic strain and H accumulation, aged Monel K-500 is susceptible to intergranular HEAC in NaCl solution when cathodically polarized at ?800 mVSCE (E A, vs saturated calomel) and lower. Intergranular cracking is eliminated by reduced cathodic polarization more positive than ?750 mVSCE. Crack tip diffusible H concentration rises, from near 0 wppm at E A of ?765 mVSCE, with increasing cathodic polarization. This behavior is quantified by thermal desorption spectroscopy and barnacle cell measurements of hydrogen solubility vs overpotential for planar electrodes, plus measured-local crevice potential, and pH scaled to the crack tip. Using crack tip H concentration, excellent agreement is demonstrated between measurements and decohesion-based model predictions of the E A dependencies of threshold stress intensity and Stage II growth rate. A critical level of cathodic polarization must be exceeded for HEAC to occur in aged Monel K-500. The damaging-cathodic potential regime likely shifts more negative for quasi-static loading or increasing metallurgical resistance to HEAC. 相似文献
997.
Quang Hung Tran Morvan Ouisse Noureddine Bouhaddi 《Mechanical Systems and Signal Processing》2010,24(1):164-181
In order to reduce vibrations or sound levels in industrial vibroacoustic problems, the low-cost and efficient way consists in introducing visco- and poro-elastic materials either on the structure or on cavity walls. Depending on the frequency range of interest, several numerical approaches can be used to estimate the behavior of the coupled problem. In the context of low frequency applications related to acoustic cavities with surrounding vibrating structures, the finite elements method (FEM) is one of the most efficient techniques. Nevertheless, industrial problems lead to large FE models which are time-consuming in updating or optimization processes. A classical way to reduce calculation time is the component mode synthesis (CMS) method, whose classical formulation is not always efficient to predict dynamical behavior of structures including visco-elastic and/or poro-elastic patches. Then, to ensure an efficient prediction, the fluid and structural bases used for the model reduction need to be updated as a result of changes in a parametric optimization procedure. For complex models, this leads to prohibitive numerical costs in the optimization phase or for management and propagation of uncertainties in the stochastic vibroacoustic problem. In this paper, the formulation of an alternative CMS method is proposed and compared to classical (u,p) CMS method: the Ritz basis is completed with static residuals associated to visco-elastic and poro-elastic behaviors. This basis is also enriched by the static response of residual forces due to structural modifications, resulting in a so-called robust basis, also adapted to Monte Carlo simulations for uncertainties propagation using reduced models. 相似文献
998.
Yu‐Kang Lo Hung‐Chun Chien Huang‐Jen Chiu 《International Journal of Circuit Theory and Applications》2010,38(7):739-746
A simple current‐input Schmitt trigger is presented and implemented. It consists of one operational transresistance amplifier and a resistor. In addition, the circuit offers dual hysteresis mode operations within the same topology. The circuit operations are described. Experimental and simulation results are given to verify the theoretical analysis. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
999.
Abstract The conjugate gradient method of minimization with adjoint equation is used successfully to solve the inverse problem in estimating an appropriate boundary control function such that the phase front moves at a desired velocity in the Stefan problem. It is assumed that no prior information is available on the functional form of the unknown control function, therefore, it is classified as the function estimation in inverse calculation. The stability and accuracy of the inverse analysis using present algorithm are examined by comparing the results of the previous work by Voller [12]. Results show that the estimated control function by using conjugate gradient method did not exhibit oscillatory behavior in the inverse calculations for a broad range of front velocity while in [12] the inverse solutions are very sensitive to phase front velocity, therefore the application of future time stepping [2] is necessary in [12]. The advantage of applying this algorithm in inverse analysis lies in its stability as compared to the conventional minimization process [12]. Artificial future time stepping is unnecessary during the inverse calculation, since it is still an uncertainty in the inverse analysis. Furthermore, the inverse solutions obtained by the present method are found to be more accurate than the solutions obtained by the conventional minimization process. 相似文献
1000.