Exact evaluation of laser linewidth requirements for optical PSKhomodyne communication systems with balanced PLL receivers

The power penalty induced by imperfect phase recovery in PSK homodyne communication systems with balanced phase-locked loop receivers are exactly evaluated. Optimum phase deviations between the mark-state and the space-state bits are used in this study. This study for the first time shows the imperfect-phase-recovery-induced power penalty as a function of laser linewidth with optimum phase deviations considered. It can be estimated from the theoretical result that an optimal balanced PLL receiver requires the laser linewidth as Δν⩽1.15×10^-6× (bit rate) in contrast to the previous reported one Δν⩽5.88×10^-6× (bit rate). We also point out here that the previously reported laser linewidth requirement was wrongly estimated     

Towards a generalized TLM algorithm for solving arbitraryreciprocal and nonreciprocal planar structures

A generalized transmission line matrix (TLM) algorithm is developed in the frequency domain to tackle arbitrary both reciprocal and nonreciprocal anisotropic waveguiding problems. In particular, the modeling issue for arbitrary planar structures is stressed in this work. A new three-dimensional (3-D) condensed node is used to consider the effect of both electric and magnetic constitutive tensors. Various results indicate how the modal dispersive behavior can be manipulated by changing not only the anisotropic characteristics of the substrate, but also the strip/slot geometry as well as the magnitude and orientation of the applied static magnetic field. The present algorithm is useful for CAD and simulation of a large class of gyrotropic waveguide-based microwave and millimeter-wave circuits     

Transdermal Iontophoretic Delivery of Thyrotropin-Releasing Hormone Across Excised Rabbit Pinna Skin

Enhanced transport of a model peptide drug thyrotropin-releasing hormone (TRH), a tripeptide of molar mass 362 g and a pK_a 6.2, through excised rabbit pinna skin was achieved by means of iontophoresis with continuous current or monophase periodically pulsed current. The resulting flux in the steady state was proportional to the applied current density. In the transdermal iontophoretic delivery of TRH, the pulsed iontophoretic flux exceeded that obtained with a continuous current. At a low ionic strength, an increased degree of protonation in TRH increased the rate of permeation. The flux of TRH in a buffer at pH 4 is greater than that at pH 8 when the ionic strength is 0.1 M. At a greater ionic strength, the trend is reversed. The enhanced flux of unprotonated TRH during transdermal iontophoresis is attributed largely to electro-osmotic volume flow. An increased rate of permeation of TRH crossing the skin is achieved at low ionic strength, moderate pH, and a large duly cycle of current; the frequency of pulsed current had no significant influence on the rate of transdermal iontophoretic delivery of TRH.     

新取代苯基荧光酮试剂的合成及其性质的研究Ⅱ．新型取代苯基荧光酮与金属离子显色反应的研究

研究了３，５－二溴－４－氨基苯基荧光酮、３，５－二溴－４－偶氮变色酸等８种苯基荧光酮在酸性介质中与高价金属离子Ｚｒ（Ⅳ）、Ｍｏ（Ⅵ）、Ｗ（Ⅵ）、Ａｌ（Ⅲ）、Ｇａ（Ⅲ）等的显色反应。３，５－位二溴取代的试剂的灵敏度高于未取代的灵敏度，摩尔吸光系数绝大多数在１０５Ｌ·ｍｏｌ－１·ｃｍ－１以上。     

Enhancement of power system data debugging using GSA-based data-mining technique

In this paper, a gap-statistic-algorithm (GSA)-based data-mining technique is applied to enhance the data debugging in power system operations. In the proposed approach, the GSA technique is embedded into a neural network frame in anticipation of improving the detection capability of bad data. Thanks to the clustering capability exhibited by GSA in which the number of clusters can be optimally determined, the proposed approach becomes highly effective to localize the group of abnormal data. This proposed approach has been tested through the data collected from different scenarios made on an IEEE 30-bus system and 118-bus systems. Test results reveal the feasibility of the method for the data diagnosis applications.     

Characterization of ultrashort optical pulses with third-harmonic-generation based triple autocorrelation

We present a method to obtain complete information of femtosecond pulses. By measuring triple-optical autocorrelation directly with third-harmonic generation, without spectral information, a temporal pulse shape can be obtained by analytical calculation without direction-of-time ambiguity. Combining the resulting optical pulse shape with its corresponding optical spectrum, the exact phase and color variations in time can all be recovered with a Gerchberg-Saxton algorithm through an iterative calculation with an O(n) complexity.     

Integrated magnetic full wave converter with flexible output inductor

A new integrated magnetic full wave DC/DC power converter that provides flexible transformer design by incorporating an independent output inductor winding is introduced. The transformer is implemented on a traditional three-leg magnetic core. The inductor winding can be separately designed to control the output current ripple. The cross-sectional area of the inductor core leg can be reduced dramatically. The operation and performance of the proposed circuit are verified on a 100 W prototype converter.     

Programmable group-delay module using binary polarization switching

We demonstrate the first programmable group-delay module based on polarization switching. With a unique binary tuning mechanism, the device can generate any differential group delay value from -45 to +45 ps with a resolution of 1.40 ps, or any true-time-delay value from 0 to 45 ps with a resolution of 0.7 ps. The delay varying speeds for both applications are under 1 ms and can be as fast as 0.1 ms. We evaluate both the dynamic and static performances of the device while paying special attention to its dynamic figures of merit for polarization-mode dispersion emulation and compensation applications. Our experiment shows that the device exhibits a negligible transient-effect induced power penalty (<0.2 dB) in a 10-Gb/s nonreturn-to-zero system.     

89-GHz fT room-temperature silicon MOSFETs

The authors report the implementation of deep-submicrometer Si MOSFETs that at room temperature have a unity-current-gain cutoff frequency (f_T) of 89 GHz, for a drain-to-source bias of 1.5 V, a gate-to-source bias of 1 V, a gate oxide thickness of 40 Å, and a channel length of 0.15 μm. The fabrication procedure is mostly conventional, except for the e-beam defined gates. The speed performance is achieved through an intrinsic transit time of only 1.8 ps across the active device region