低压长袋脉冲袋式除尘器设计与应用

以工业原料尤里卡沥青(EP)为对象，详细论述了低压长袋脉冲袋式除尘器的主要设计环节，着重分析了新型脉冲阀技术。指出了该技术在化肥行业原料干燥、风扫制备等方面的推广应用和发展趋势。     

LFP-941D线路保护重合闸问题浅析

通过对一次线路保护传动时保护装置不发重合闸脉冲的问题进行分析,论述了保护装置启动展宽及重合闸脉冲在延时上的配合问题。     

降低妈湾电厂空预器漏风率的措施

为降低空预器漏风率，从结构设计分折得出空、烟气压差大和密封间隙大是其漏风的主要原因，通过采取高压水冲洗，气脉冲燃气吹灰，双密封改造，空预器重新选型等一系列措施来降低漏风率。     

拓宽调速范围的微机PWM变频传动系统

本文对单CPU结构的PWM变频调速系统做了一些探讨。为解决系统中存在的微机计算速度偏低和硬件复杂性问题,较好地处理软件和硬件的配合问题,本文提出了在较少的硬件结构基础上,通过在线设置辅助数据表,实现计算和存贮相结合的PWM方式:在设计中,利用了微机键盘和显示器实现系统管理。为解决电动机低速运行时机械特性变软这一问题,本文提据电动机定子电压和频率的协调控制原则,实现以电动机基波电流和功率因数为反馈信号的协调控制。实验结果表明,所设计的变频调速系统具有较宽的调频范围、较高的电压及频率分辨率,低速带负载能力大为改善,操作灵活方便。     

基于PRONY模型的谐波检测

信号的去噪问题一直是信号检测的一大难题,而要检测的信号往往却存在不同的随机噪声。在分析周期信号的基础上,提出了一种基于PRONY模型的周期信号分析法。经过对周期短(窄)脉冲信号的实验,这种直接构造的PRONY算法在周期信号中能达到有效、准确的分析结果。     

Study on characteristics of Ni-W-B composites containing CeO2 nano-particles prepared by pulse electrodeposition

Ni-W-B composites containing CeO2 nano-particles on the surface of 45 steel were prepared by pulse electrodeposition,and the in-fluence of pulse frequency,pulse duty circle and heat treatment temperature on the structures and properties were investigated.The results in-dicated that the pulse co-deposition of Ni,W,B and CeO2 nano-particles led to Ni-W-B/CeO2 composites possessing higher microhardness and better wear resistance when heat-treated at 400 oC for 1 h.The microhardness of 636 HV and the deposition rate of 0.0281 mm/h of the as-deposited alloy were the highest at pulse frequency of 1000 Hz,pulse duty circle of 10% and pulse average current density of 10 A/dm2.The composites were mainly in the amorphous state and were partially crystallized as-deposited,and the crystallization trend was strength-ened when heat-treated at 400 oC.Decreasing pulse duty cycle from 75% to 10% was favorable to the refinement in grain structures and im-provement of microstructures.The crystal sizes of the composites were smaller by means of pulse electrodeposition.     

热释光探测器在脉冲硬X射线能谱测量中的应用

介绍了TLD－3500热释光读出器和GR－100M型热释光剂量片构成的探测器在脉冲硬X射线辐射参数测量中的应用。详细论述了采用滤波荧光法与热释光探测器相结合测量10－10keV的硬X射线能谱的物理思想，在综合考虑了测量环境的具体情况下，设计研制了硬X射线测量系统，建立了热释光探测器对硬X射线绝对能量响应的标定方法。该方法已成功用于脉冲辐射装置“强光1号”的测量，并得到了实测数据。     

基于提升静态小波包变换的自适应消噪方法

基于离散小波变换(DWT)的自适应消噪方法为雷达信号的滤波提供了一种可行的方法.但DWT不具有平移不变性,若不用相同的小波对滤波后的信号进行重构,则会带来较大的重构误差.针对这一现象,提出了一种基于提升静态小波包变换的自适应消噪方法,它推导了静态小波包的提升实现方法,并设计出适合该系统的确定最优小波包分解树的相应步骤,利用引入更多动量因子的权系数迭代公式对各子带进行自适应匹配,并将匹配结果二次自适应,得到拟合的原信号.仿真结果表明,该方法可在计算量增加不大的前提下,进一步改善系统的滤波性能.     

Liquid Letters

Using the interfacial jamming of cellulose nanocrystal (CNC) surfactants, a new concept, termed all‐liquid molding, is introduced to produce all‐liquid objects that retain the shape and details of the mold with high fidelity, yet remain all liquid and are responsive to external stimuli. This simple process, where the viscosity of the CNC dispersion can range from that of water to a crosslinked gel, opens tremendous opportunities for encapsulation, delivery systems, and unique microfluidic devices. The process described is generally applicable to any functionalized nanoparticles dispersed in one liquid and polymer ligands having complementary functionality dissolved in a second immiscible liquid. Such sculpted liquids retain all the characteristics of the liquids but retain shape indefinitely, very much like a solid, and provide a new platform for next‐generation soft materials.