FTSR铁素体轧制过程的温度场模拟

以传热学的基本理论为基础,建立了热平衡方程,采用完全隐式差分法对FTSR(Flexible Thin Slab Rolling)薄板坯连铸连轧生产线上隧道炉,轧制及冷却过程中的板坯中心温度和表面温度变化进行了模拟。可以得到以下结论:(1)在加热炉内,表面温度优先达到设定的温度,板坯出炉时表面和心部温度相同,达到了均热的效果。(2)在轧制过程中,板坯上表面温度急剧下降,道次间歇期间又有回升的趋势。在冷却过程中,板坯上表面温度迅速下降。(3)计算的板坯表面温度与实测的表面温度吻合较好。表明该模型可以用来模拟该生产线的温度变化,对工艺的设定具有一定的指导意义。     

基于VxD的发动机瞬时转速测量装置

基于VxD的发动机瞬时转速测量系统由磁电式传感器、信号调理电路、高速数据采集卡、PC及数据处理模块构成。调理电路将磁电式传感器产生的齿轮旋转逐齿信号调为矩形脉冲。VxD控制采集卡采集矩形脉冲,并将数据成组向PC传送。经程序运算得到每个脉冲周期的采样点数,瞬时脉冲频率和周期。     

Flexible,self-cleaning,and high-performance ceramic nanofiber-based moist-electric generator enabled by interfacial engineering

Due to their long-term stability, even under extreme conditions, oxide ceramics have attracted significant attention in emerging fields like moist-electric generation However, the inherent brittleness and low voltage output of oxide ceramic-based moist-electric generators (MEGs) limit their applications in wearable electronics. Herein, a facile strategy involving the combination of sol-gel electrospinning and calcination is used to fabricate flexible and freestanding TiO₂/ZrO₂ (TZ) composite nanofiber-based MEGs. The excellent flexibility of the TZ nanofiber membranes can be attributed to the suppression of their crystal structure transformation, dispersion of stress concentration, and reduction of crack propagation via interfacial engineering The porous structure of the electrospun nanofiber membrane features an abundance of charged narrow channels for the diffusion of water molecules and generates a streaming potential: The optimal voltage output reached ～0.8 V, which is the highest value reported for an oxide ceramic-based MEG. Furthermore, the as-fabricated nanofiber-based MEG exhibits good self-cleaning capability to degrade organic pollutants under ultraviolet irradiation. By integrating mechanical flexibility, high performance, and a self-cleaning effect, this work presents a new idea for exploring diverse, efficient, and wearable oxide ceramic-based MEGs.

     

Controllable diameter of electrospun nanofibers based on the velocity of whipping jets for high-efficiency air filtration

Science China Technological Sciences - Electrospun nanofibers are regarded as a promising candidate for filtration because of their prominent size effect. The precise control of nanofiber diameter...