响应面法优化脉冲电氧化处理茜素红废水

采用响应面法,评估了脉冲电氧化处理茜素红染料废水的实验变量影响和预测最优操作条件。选用TOC去除率和能耗为模型响应值,脉冲占空比、电流密度、溶液流速和电源频率为实验变量。实验分析及模型优化结果显示:电流密度和占空比对响应目标的影响是显著的,溶液流速和电源频率是非显著的。当脉冲占空比为0.49、电流密度为10.00 mA/cm^2、流量为2.40 m/h、电源频率为1.81 kHz时,响应面模型优化的TOC去除率为49.20%,去除单位质量TOC能耗为94.14 kWh/kg。相同条件下非脉冲直流电氧化对TOC去除率为51.31%,去除单位质量TOC能耗为157.20 kWh/kg。两者相比,脉冲电氧化工艺节能40.11%,优势明显。     

宇宙光点明灭间的灿然与超然 ——《朝闻道》中人类殉道始末与宇宙终极哲学

刘慈欣的作品常常以表现技术的宏大美感为宗旨,呈现出硬科幻的典型范式。在《朝闻道》中, 技术之美虽也层出不穷,不断地冲击着人们的思维界限然而,一种更为形而上的概念凌驾于科技之上,成就 了整部作品的基调。《朝闻道》中,无论是人物的塑造还是故事的架构,甚至其中更深层的寓意和思考全部 基于对人类求知精神的礼赞,正如这部作品的题目一样展现了一种崇高和超脱之美。     

Pressure-controlled terahertz filter based on 1D photonic crystal with a defective semiconductor

The tunable terahertz (THz) filter has been designed and studied,which is composed of 1D photonic crystal (PC) containing a defect layer of semiconductor GaAs.The analytical solution of 1D defective PC (1DDPC) is deduced based on the transfer matrix method,and the electromagnetic plane wave numerical simulation of this 1DDPC is performed by using the finiteelement method.The calculated and simulated results have confirmed that the filtering transmittance of this 1DDPC in symmetric structure of air/(Si/SiO2)N/GaAs/(SiO2/Si)N/air isfar higher than in asymmetric structure of air/(Si/SiO2)N/GaAs/(Si/SiO2)N/air,where the filtering frequency can be tuned by the external pressure.It can provide a feasible route to design the external pressure-controlled THz filter based on 1DPC with a defective semiconductor.