用亚椭圆形毛料提高盒形件成形的研究

在盒形件拉伸成形过程中,毛料展开是冲压工作的重要课题。此文根据数学理论,用亚椭圆方法建立数学模型来摸拟盒形件毛料尺寸展开外形,是提高一次成形、减少压延次数的有效方法。     

径向辗环变形的数学模型与尺寸控制方式

辗环是生产无接缝环圈的先进技术之一,此文分析了辗环过程及变形,建立了径向辗环变形过程的数学模型,以此为据制定的程序。使φ500型齿轮毛坯辗扩机实现了在线预测智能型尺寸控制。此控制系统投资少、结构简单、性能稳定可靠,在实际生产中使坯件尺寸精度达到:△φ±1mm,保证了稳定生产。     

不同材质采样器采样对降水离子组分的影响研究

采用了四种材质即聚乙烯、聚氯乙烯、硬质玻璃和金属加特氟龙涂层采样器，在同一地点、同一时间采集同一场降雨，所获得的样品经过中速定量滤纸过滤，在相同实验条件下进行离子色谱分析。结果表明：聚氯乙烯材质采样器采集的降水样品pH值降低，电导率升高，且使其中的氯离子浓度产生显著性差异，其余材质采样器所采集的降水样品中的各阴离子浓度无显著性差异；四种材质采样器所采样的降水样品中的各阳离子浓度也无显著性差异。     

Bibliometric analysis of the research landscape on rice husks gasification (1995–2019)

Environmental Science and Pollution Research - The processing of rice (Oryza sativa L.) generates large quantities of lignocellulosic wastes termed rice husks (RH). Numerous researchers have...     

Iron-doped copper 1,4-benzenedicarboxylate as photo-Fenton catalyst for degradation of methylene blue

Abstract

A metal-organic framework of iron-doped copper 1,4-benzenedicarboxylate was synthesized and, for the first time, utilized as a heterogeneous photo-Fenton catalyst for degradation of methylene blue dye in aqueous solution under visible light irradiation. The synthesized materials were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. The influence factors, kinetics, and stability of the synthesized catalysts were investigated in detail. Iron-doped copper 1,4-benzenedicarboxylate showed higher degradation efficiency than pure copper 1,4-benzenedicarboxylate. An almost complete degradation was achieved within 70?min under visible light irradiation at a solution pH of 6, a catalyst loading of 1?g?L^?1, a H₂O₂ dosage of 0.05?mol L^?1 and methylene blue concentration of 50?mg?L^?1. Recycling studies demonstrated that the iron-doped copper 1,4-benzenedicarboxylate is a promising heterogeneous photo-Fenton catalyst for long-term removal of methylene blue dye from industrial wastewater.