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排序方式: 共有246条查询结果,搜索用时 15 毫秒
81.
《Ceramics International》2023,49(20):32727-32738
Insufficient permeability and membrane fouling significantly influence the efficiency of ceramic microfiltration (MF) membranes in oil/water emulsion treatment. In this study, a high-flux whisker layer ceramic MF membrane with super-hydrophilicity was successfully fabricated through gel-spin coating method and a low-temperature oxidation method, which was used to separate oil/water emulsion. The effects of the whisker layer and surface wettability were systematically investigated, and the mechanism of in-situ gelling and pore size distribution was proposed. The super-hydrophilic ceramic MF membrane with an average pore size of 250 nm exhibited a high gas flux of 934 m3/(m2·h·bar) and excellent pure water flux of 9754 L/(m2 h bar). Even after a long-term circulating filtration process, the super-hydrophilic ceramic MF membrane still maintained a high water flux of over 50 L/(m2·h) at a transmembrane pressure of 5 KPa during the treatment of oil-in-water emulsion with a concentration of 1000 mg/L. Overall, the developed ceramic MF membrane demonstrated high permeability and excellent anti-fouling performance, making it a promising candidate for oil/water emulsion wastewater treatment. 相似文献
82.
针对协作非正交多址(NOMA)系统中信息安全传输问题,该文提出一种基于修改转发(MF)中继的物理层安全(PLS)传输方案。该方案利用MF中继将解码信息修改后再转发,避免了合法信息泄露到窃听节点。首先对NOMA-MF系统进行建模,然后推导了系统安全中断概率(SOP)、严格正保密容量(SPSC)和窃听概率(IP)来衡量系统的保密性和安全性,以及中断概率(OP)以衡量其可靠性。此外,推导了系统的渐近性能,对比分析了解码转发(DF)协议下NOMA-DF系统与NOMA-MF系统的性能。推导及仿真结果表明:NOMA-MF系统的保密性能和安全性能比NOMA-DF系统更具有优势;NOMA-MF系统的OP和IP之间存在最优信噪比(SNR)以实现系统安全及可靠性的平衡;存在最佳功率分配参数以实现最低的SOP和OP。 相似文献
83.
染色大小样色差是困扰染色生产的最主要问题。染色大小样不符的一个重要原因就是大小样染色工艺差异太大。从染色工艺方面着手,通过正交试验设计方法,找出影响羊绒织物绞纱染色大小样色差的最主要因素,调整出合理的工艺参数,制定出符合企业生产的优化的工艺曲线,最终达到减少绞纱染色色差的目的。 相似文献
84.
基于检测的目标跟踪方法目前在计算机视觉领域受到了广泛的关注,这类方法通过训练判别分类器将目标对象从背景中分离出来;分类器的训练是根据当前的跟踪状态从当前帧中提取正负样本来进行,但训练样本的不准确将导致分类器退化产生漂移。该文提出一种能够有效克服目标漂移的跟踪算法,采用检测器和跟踪器相结合的框架,利用中值流算法作为跟踪器,提高跟踪点的可靠性;级联若干个随机蕨弱分类器构成强分类器作为检测器;用在线多示例学习方法更新检测器,提高检测精度;最后将检测器、跟踪器的结果相融合得到最终的目标位置。实验结果表明,与其它方法相比,该方法对目标漂移有更强的鲁棒性。 相似文献
85.
86.
Preparation and characterization of PAA/PVDF membrane-immobilized Pd/Fe nanoparticles for dechlorination of trichloroacetic acid 总被引:2,自引:0,他引:2
Poly(vinylidene fluoride) (PVDF) microfiltration (MF) membrane was successfully hydrophilized by coating with a novel hydrophilic layer, which was mainly composed of polyvinyl alcohol (PVA), glutaraldehyde, and polyethylene glycol (PEG). Pd/Fe nanoparticles (NPs) were prepared and immobilized in hydrophilized polyacrylic acid (PAA)/PVDF MF membrane. The unmodified and modified PVDF MF membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The membrane-supported Pd/Fe NPs exhibited high reactivity in the dechlorination of trichloroacetic acid (TCAA). The effects of several important parameters, including Pd content, Pd/Fe NP loading, the preservation time of Pd/Fe NP membrane system on the dechlorination of TCAA were investigated. The stability of Pd/Fe NP membrane system was tested, and the kinetics and product distribution of dechlorination of TCAA by Pd/Fe NP membrane system were discussed. 相似文献
87.
88.
Fluid dynamic gauging (FDG) was used to track the thickness of the cake layer formed during the microfiltration of a 45° Brix molasses solution using a 1.5 μm polysulphone membrane. A simultaneous measure of flux and deposit thickness throughout the full membrane operating cycle is reported. Asymptotic fouling thicknesses of ca. 100 μm are developed after 30 min of filtration. Accordingly, flux declines are severe at ca. 93%. Permeate line closed (PLC) operation leads to the complete removal of the deposit layer, and the recovery of 60% of the flux. However, permeate line open (PLO) operation leads to only a 50% flux recovery and an asymptotic deposit thickness of 10 μm. An initial increase and subsequent reduction in flux during chemical cleaning has also been recorded for both acid and alkali cleaning regimes. Effective cleaning regimes for membranes fouled by molasses require an alkali stage followed by an acid stage. 相似文献
89.
A new method called joint Matched Filter (MF) combining and turbo equalization is proposed for wireless communications over
Inter-Symbol Interference (ISI) channels with diversity reception. This method takes diversity combining and equalization
as integrity and need just one turbo equalizer for all diversity branches. Computer simulations prove that our method can
take advantage of turbo equalization and diversity reception to combat fading of wireless channels. 相似文献
90.
Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination 总被引:1,自引:0,他引:1
Byung Soo Oh Youn Young Hwang Joon-Wun Kang 《The Science of the total environment》2010,408(23):5958-5965
From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate. 相似文献