Microdischarge arrays: a new family of photonic devices

The optical and electrical characteristics of microdischarge devices and arrays fabricated in semiconductors and metal/polymer structures are described. Devices as small as (10 μm)² in emitting area (nanoliters in volume) and arrays as large as 30 × 30 have been demonstrated and operated at gas pressures up to and exceeding one atmosphere. This new generation of microoptical sources is capable of producing photons from the infrared to the vacuum ultraviolet and beyond and is well suited for integration with microoptoelectronic, fluidic, and mechanical systems     

Two-dimensional photonic crystal semiconductor lasers: computational design, fabrication, and characterization

We have designed, fabricated, and tested two-dimensional (2-D) slab photonic crystal semiconductor lasers at communication wavelengths. Wavelength-size microresonators defined on the 2-D slab photonic crystal have been effective in photon confinement and functioned well as ultra-small lasers by optical pumping. The photonic crystal laser structures that we have tested have shown large quality factors and low thresholds.     

HVDC用电容器装置现场臂间调平方法研究

本文介绍了一种交流滤波电容器装置现场测试及调平的工作原理以及具体调平方法。主要阐述了交流滤波电容器装置在现场投运时,初始不平衡电流过大,超过了保护所要求的初始不平衡电流值,现场对装置内单台电容器进行调换,并经过现场测试验证,达到了初始不平衡电流的要求。     

Optimal Tuning for Linear and Nonlinear Parameters of Power System Stabilizers in Hybrid System Modeling

This paper focuses on the systematic optimal tuning of the power system stabilizer (PSS), which can improve the system damping performance immediately following a large disturbance. As the PSS consists of both linear parameters (such as the gain and time constant) and nonsmooth nonlinear parameters (such as saturation limits of the PSS), two methods are applied for the optimal tuning of all parameters. One is to use the optimization technique based on the Hessian matrix estimated by the feedforward neural network, which identifies the first-order derivatives obtained by the trajectory sensitivities, for the nonlinear parameters. Moreover, the other is to use the eigenvalue analysis for the linear parameters. The performances of parameters optimized by the proposed method are evaluated by the case studies based on time-domain simulation and real-time hardware implementation.     

Optical and electrical properties of ZnO thin film containing nano-sized Ag particles

Low-temperature crystallized ZnO thin film was achieved by sol–gel process using zinc acetate dihydrate and 2-methoxyethanol as starting precursor and solvent, respectively. Ag nanoparticles were prepared with uniform size at 4.4 nm by spontaneous reduction method of Ag 2-ethylhexanoate in dimethyl sulfoxide (DMSO). The optical and electrical properties of ZnO thin films containing various contents of Ag-nanoparticles were monitored. Light scattering and charge emission and scattering behaviors of Ag nanoparticles in ZnO film were found. The incorporation of Ag nanoparticles into Al-doped ZnO film was also investigated. The optical transmittance was not degraded but the increase of electrical sheet resistance was found. The effect of Al-dopant on the transmittance and electrical sheet resistance of ZnO film was found too great to distinguish the positive effect of the incorporation of Ag nanoparticles into Al-doped ZnO thin films.     

风电场升压站设计的探讨

通过对风电场接入电网的新规定、新反措的分析,探讨了风电场升压站设计中的若干问题,提出了一些建议和方案。     

Thick Film Planar CO<Subscript>2</Subscript> Sensors Based on Na β-Alumina Solid Electrolyte

Practical small-sized thick film CO₂ sensor with self-heater was fabricated with Na β -Alumina (NBA), Na₂Ti₆O₁₃-TiO₂, and Na₂CO₃ as a solid electrolyte, reference electrode, and a sensing electrode, respectively. The measured EMF from the sensor followed the Nernstian behavior with CO₂ concentration change in the range of 400 to 600^∘C (350–580 mW power consumption). However, in the aspect of stability, densification of the NBA thick film and prevention of Na₂CO₃ evaporation were needed. In this study, an Al₂O₃ porous layer deposited on Na₂CO₃ was effective in improving the durability during operation of the sensor. It is thought that Al₂O₃ suppresses evaporation of Na₂CO₃.     

Operation of 1550-nm electroabsorption-Modulated laser at 40/spl deg/C for 10-gb/s, 40-km transmission

Semicooled operation at 40/spl deg/C of electroabsorptive modulator integrated laser (EML) for intermediate reach communication has been demonstrated. Reproducible operation at the elevated temperature was achieved through a device parameter optimized based on the temperature dependence of the dc characteristics of EML and a design of multi-quantum-well structure providing both relevant output power and high-frequency bandwidth at 40/spl deg/C. Good eye pattern and near zero chirp with the average power over 0 dBm are obtained at 40/spl deg/C, with an estimated lifetime over 20 years.     

Development of small robot using piezoelectric benders

Abstract

In this paper, a piezoelectric small robot was proposed and experimented. The piezoelectric bender of the actuator was composed of trapezoid ceramics which were attached on both surfaces of the elastic body. And an X-shaped structure was composed of four piezoelectric ceramic benders. When AC voltages which have different duty ratio were applied to the four benders, the motion of straight line according to a stick slip of the bender tips was obtained. A FEA simulation was used to analyze the motion of straight line. The output characteristics of the prototype actuator which was fabricated based on the analysis data were measured.     

Continuous-wave low-threshold performance of 1.3-μm InGaAs-GaAsquantum-dot lasers

The understanding of material quality and luminescence characteristics of InGaAs-GaAs quantum dots (QD's) is advancing rapidly. Intense work in this area has been stimulated by the recent demonstration of lasing from a QD active region at the technologically important 1.3-μm wavelength from a GaAs-based heterostructure laser. Already, several groups have achieved low-threshold currents and current densities at room temperature from In(Ga)As QD active regions that emit at or close to 1.3 μm. In this paper, we discuss crystal growth, QD emission efficiency, and low-threshold lasing characteristics for 1.3-μm InGaAs-GaAs QD active regions grown using submonolayer depositions of In, Ga, and As. Oxide-confinement is effective in obtaining a low-threshold current of 1.2 mA and threshold-current density of 19 A/cm² under continuous-wave (CW) room temperature (RT) operation. At 4 K, a remarkably low threshold-current density of 6 A/cm² is obtained