聚偏氟乙烯膜蒸馏技术在水处理中的应用研究进展

膜蒸馏是一种以膜为介质,利用传统蒸发工艺开发的新型膜分离技术。随着高分子材料行业的进步和制膜工艺的成熟,膜蒸馏技术取得了巨大的进展,在水处理领域拥有十分广阔的市场前景。膜蒸馏技术的核心是膜的通量和使用寿命,而性能优良的膜材料是膜蒸馏技术发展的关键。聚偏氟乙烯(PVDF)因具有成膜性能好、表面张力大、化学稳定性强等优点,在膜蒸馏技术应用研究中备受青睐。同时PVDF与其他聚合物具有良好的相容性,为膜的改性研究奠定了基础,极大地扩展了应用范围。本文介绍了膜蒸馏技术的工作原理及工艺特点以及PVDF膜材料的特点及改性方法,重点对PVDF膜蒸馏技术在水处理领域的应用进行了梳理和总结,讨论了该技术亟待研究和解决的问题,以期为该工艺技术的进一步发展提供科学支撑和理论依据。     

弥散补偿飞秒激光器

本文介绍一套CW锁模内腔倍频Nd:YAG激光器同步泵浦弥散补偿飞秒激光系统。该激光系统能够稳定地产生持续期38fs、重复频率200MHz、平均输出功率20mW的光脉冲。本文还讨论了泵浦源的结构。     

A SIMPLE PROOF OF THE INEQUALITY MFFD（L）≤（71／60）OPT（L）＋1，L FOR THE MFFD BIN－PACKING ALGORITHM

ＡＳＩＭＰＬＥＰＲＯＯＦＯＦＴＨＥＩＮＥＱＵＡＬＩＴＹＭＦＦＤ（Ｌ）≤（７１／６０）ＯＰＴＬ）＋１，ＬＦＯＲＴＨＥ　ＭＦＦＤＢＩＮ－ＰＡＣＫＩＮＧＡＬＧＯＲＩＴＨＭＹＵＥＭＩＮＹＩ（越民义）（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ...     

Postsynaptic Potentials and Morphological Features of Tectal Cells in Homing Pigeons

In this study postsynaptic potentials responding to the electrical stimulation of the optic nerve and the nucleus isthmipars parvocellularis (Ipc) were intracellularly recorded from 86 tectal cells in pigeons, 13 of which were marked with Lucifer yellow (LY). According to types of postsynaptic potentials and their succesion, the postsynaptic responses could be classified into four types: excitatory postsynaptic potential (EPSP)-inhibitory postsynaptic potential (IPSP) sequence (EI type), E, I and IE types.Among them, E or EI responses were mainly produced to the optic nerve stimulation, while the electrical stimulation of the lpc elicited I responses in more than half the recorded cells.LY-marked tectal cells included five ganglionic cells, four pyramidal cells, two bipolar cells and two stellate cells.The ganglionic cells were mainly located in tectal layers Ⅲ and Ⅳ, whereas the others were in layer Ⅱ.It appears from both intracellular recordings and fluorescent markings that there is some correlati     

基于一种新微细加工技术的亚波长光栅的研制

描述了一种新的亚波长光栅的微细加工技术，即电子束（EB）扫描曝光得到相应的亚微米级的线宽图形，再利用快速原子束刻蚀设备获得了高深宽比的立体结构。用此加工技术获得了100nm以下的刻蚀精度，并研制成功亚波长光栅。该亚微米线宽微细加工技术可用于布拉格光栅、半导体激光器、无反射表面等需要亚微米结构的器件中。     

LBER多用户检测算法性能的研究

在多径信道环境下,在下行链路对最低误比特率(MBER)多用户检测算法的性能进行了研究,并通过核密度函数估计方法将其推广到自适应的最小误比特率(LBER)多用户检测算法。仿真结果表明:LBER算法具有收敛速度快和计算复杂度低的特点;在一定的信噪比条件下,LBER算法有比MMSE多用户检测算法更低的误比特率(BER),其抗远近效应能力也优于传统的MMSE检测算法。