PDLC膜制备及响应特性研究

本文从ＰＩＰＳ法制备ＰＤＬＣ膜出发，探讨了工艺条件对响应特性，尤其是响应时间的影响。并对制备工艺提出一些改进措施。     

铁电液晶红外探测研究

某些碟状近晶相液晶具有铁电和热电性质。本文综述了铁电液晶的性质和介电、热电及脉冲响应特性;报道了我们对复合固体铁电液晶薄膜探测器的最新研究成果。     

Space charge limitation on the response time of organic photodiodes

The dynamic response of an organic bulk heterojunction photodiode to small changes in applied bias or light intensity is investigated as function of the intensity of a constant background illumination by means of photoimpedance and transient photocurrent measurements. For bias voltages close to the open circuit voltage we find that the response timescale with the square root of the light intensity. The results can be quantitatively explained in terms of a space charge limitation on the photocurrent as predicted by Goodman and Rose (J. Appl. Phys. 42, 2823 (1971)). The relaxation time of the diode at open circuit corresponds to the lifetime of the slowest charge carrier in the diode. This relaxation time is determined by the dielectric constant and the smallest of the two carrier mobilities in the bulk heterojunction. This illustrates the importance of balanced carrier mobilities for obtaining diodes with fast response time at low bias for e.g. imaging arrays.     

Cascading of liquid crystal elastomer photomechanical optical devices

Photomechanical actuation is demonstrated in two coupled liquid crystal elastomer photomechanical optical devices (PODs) acting in series. The response function of an individual POD is characterized and used to predict the temporal response of the coupled system. The predicted coupled-system response agrees with the experiment for several waveforms and frequencies, suggesting that large-scale integration of photomechanical devices is possible.     

Approximate and Exact Small Signal Analysis for Single-Mode Fiber Near Zero Dispersion Wavelength with Higher Order Dispersion

This article presents the comparison of approximate and exact small-signal theories for analyzing the influence of the higher-order dispersion terms on dispersive optical communication systems operating near zero dispersion wavelength for linear single-mode fiber. For the approximate theory, the generalized conversion matrix has been reported and gives the transfer function of intensity and phase from the fiber input to fiber output for a laser source including the influence of any higher-order dispersion term. In addition, expressions for the small-signal frequency response and the relative intensity noise (RIN) response of an ultrafast laser diode including noises are derived. However, it is observed that the approximation assumed for the second-order dispersion term for the approximate analysis is not valid. From the approximate theory, the exact generalized conversion matrix and exact expressions for small-signal frequency response and relative intensity noise (RIN) are obtained. We show that for the exact theory, the second-order dispersion term has no effect on intensity and frequency response even at large modulating frequencies and large propagation distances contrary to the approximate theory as reported by other authors. But we show that third-order dispersion term certainly has some minute impact on the frequency and RIN response for long distance links at high modulating frequencies.     

宽带LAN平均响应时间限值与流量最大容限--四层协议模型近似解析

以均匀宽带ＬＡＮ四层协议通信模型为对象,对系统流量的最大容限在给定系统平均响应时间限值的条件下进行了数学解析。对平均响应时间限值与流量最大容限的关系以及系统流量的不平衡性对平均响应时间的影响进行了数值分析,并得出了有价值的结论。     

基于纳什均衡的需求响应多用户策略研究

随着能源互联网的出现和智能电网的发展,使得电能供给与电能需求能够更紧密的联系,也促进了电力交易市场条件下需求响应的信息化和智能化,用户根据自身情况在需求响应市场上进行出价与竞争,也更好的反映了电能的市场价值.本文结合智能电网下的需求响应市场,描述了多用户对电能竞争的一般场景与模型,从理论和算法上分析用户出价与市场调节的...     

Effect of Polyethylene glycol methyl ether blend Humic acid on poly (vinylidene fluoride-co-hexafluropropylene) PVDF-HFP membranes: pH responsiveness and antifouling behavior with optimization approach

Flat sheet asymmetric membranes were fabricated with homogeneous solution of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) using N-methyl-2-pyrrolidone (NMP) as solvent via phase inversion method. PEGME (Poly ethylene glycol methyl ether) (M_n 5000) blend Humic Acid (HA), of different mole ratio was used as additive. Characterization of the membranes was done by Field emission scanning electron microscope (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, Atomic force microscopy (AFM) and Differential scanning calorimetry (DSC) studies. Liquid-liquid displacement porosimetry (LLDP) study evaluated the morphological parameters, average pore size and pore size distribution. Bovine serum albumin (BSA) (M_W - 68,000 Da) was used to study the antifouling effect and pore blocking mechanism of the membranes. The pure water flux (PWF), solute rejection and flux recovery ratio drastically increases for the PEGME blended HA membranes whereas the water contact angle decreases significantly. The pH responsiveness character of the prepared membranes altered the hydraulic permeability and rejection % at different pH. Finally, optimization of the variables contributing towards the PWF and BSA rejection of the desired membrane was performed using Design expert software 9.0 TRIAL through ANOVA (analysis of variance) using the combination of response surface methodology (RSM) and central composite design (CCD).     

Multivariate optimization of hydrodistillation-headspace solvent microextraction of thymol and carvacrol from Thymus transcaspicus

In this paper multivariate response surface methodology (RSM) has been used for the optimization of hydrodistillation-headspace solvent microextraction (HD-HSME) of thymol and carvacrol in Thymus transcaspicus. Quantitative determination of compounds of interest was performed simultaneously using gas chromatography coupled with flame ionization detector (GC-FID). Parameters affecting the extraction efficiency were assessed and the optimized values were 5 min, 2 μL and 3 min for the extraction time, micro-drop volume and cooling time after extraction, respectively. The amounts of analyte extracted increased with plant weight. The calibration curves were linear in the ranges of 6.25-81.25 and 1.25-87.50 mg L⁻¹ for thymol and carvacrol, respectively. Limit of detection (LOD) for thymol and carvacrol was 1.87 and 0.23 mg L⁻¹, respectively. Within-day and between-day precisions for both analytes were calculated in three different concentrations and recoveries obtained were in the range of 89-101% and 95-116% for thymol and carvacrol, respectively.