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In-Plane Thermal Diffusivity Measurement of Thin Films Based on the Alternating-Current Calorimetric Method Using an Optical Reflectivity Technique 下载免费PDF全文
An advanced ac calorimetric method to measure thermal diffusivity of a thin sample is developed by using an optical reflectivity technique. A modulated infrared laser is used to heat the front surface of a foil specimen. The reflectivity of a continuous-wave He-Ne laser at the rear surface of the specimen is detected by a photoreceiver. 相似文献
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针对校验矩阵不具备准循环结构的1类低密度奇偶校验(low density parity check,LDPC)码,采用改进的LU分解法,设计了1种低复杂度的LDPC码编码器。通过运用流水线技术与乒乓缓存技术,显著降低了存储资源的消耗,提升了吞吐率。同时,该编码器适用于所有校验矩阵能进行LU分解的LDPC码,具有良好的应用价值。 相似文献
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Thermal Conductivity Measurement of Submicron-Thick Aluminium Oxide Thin Films by a Transient Thermo-Reflectance Technique 下载免费PDF全文
Thermal conductivity of submicron-thick aluminium oxide thin films prepared by middle frequency magnetron sputtering is measured using a transient thermo-reflectance technique. A three-layer model based on transmission line theory and the genetic algorithm optimization method are employed to obtain the thermal conductivity of thin films and the interracial thermal resistance. The results show that the average thermal conductivity of 330- 1000nm aluminium oxide thin films is 3.3 Wm^-1K^-1 at room temperature. No significant thickness dependence is found. The uncertainty of the measurement is less than 10%. 相似文献
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针对目前20kHz/10kW感应加热电源开关功耗大的缺点,提出了一种基于DSP的容性移相PWM和PFM控制的设计方案。确定以全桥IGBT逆变为主拓扑电路,采用PID和DPLL相结合的双闭环控制策略,对系统进行SIMULINK平台仿真建模。在开环和闭环条件下对仿真结果进行对比分析,实现了负载频率自动跟踪和功率闭环控制。仿真系统到达恒定功率输出的时间为0.2ms,功率因数近似为1,且无周期跳变的现象。改善系统动态特性和稳定控制的同时,验证了该方案的可行性和有效性。 相似文献
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This paper introduces a low-cost infrared absorbing structure for an uncooled infrared detector in a standard 0.5 m CMOS technology and post-CMOS process. The infrared absorbing structure can be created by etching the surface sacrificial layer after the CMOS fabrication, without any additional lithography and deposition procedures. An uncooled infrared microbolometer is fabricated with the proposed infrared absorbing structure.The microbolometer has a size of 6565 m2and a fill factor of 37.8%. The thermal conductance of the microbolometer is calculated as 1.3310 5W/K from the measured response to different heating currents. The fabricated microbolometer is irradiated by an infrared laser, which is modulated by a mechanical chopper in a frequency range of 10–800 Hz. Measurements show that the thermal time constant is 0.995 ms and the thermal mass is 1.3210 8J/K. The responsivity of the microbolometer is about 3.03104V/W at 10 Hz and the calculated detectivity is 1.4108cm Hz1=2/W. 相似文献