PVC/PAN 共混超滤膜的研究 Ⅰ.PVC 与 PAN 相容性对共混超滤膜结构与性能的影响

在增混剂用量固定情况下,PVC 与PAN 的共混比直接影响其相容性。而相容性主要对PVC/PAN 共混超滤膜的表层孔径产生影响。相容性较好时,表层孔径极小,膜呈明显的不对称性,截留率高,但透水率较低,反之亦然。可见,通过对两种高聚物相容性的调整,有可能在一定范围内实现对超滤膜平均孔径的控制,尤其对制备技术难度较大的大孔径超滤膜可期有实用价值。     

Curing of low level melamine‐modified urea‐formaldehyde particleboard binder resins studied with dynamic mechanical analysis (DMA)

Effects of resin formulation, catalyst, and curing temperature were studied for particleboard binder‐type urea‐formaldehyde (UF) and 6 ～ 12% melamine‐modified urea‐melamine‐formaldehyde (UMF) resins using the dynamic mechanical analysis method at 125 ～ 160°C. In general, the UF and UMF resins gelled and, after a relatively long low modulus period, rapidly vitrified. The gel times shortened as the catalyst level and resin mix time increased. The cure slope of the vitrification stage decreased as the catalyst mix time increased, perhaps because of the deleterious effects of polymer advancements incurred before curing. For UMF resins, the higher extent of polymerization effected for UF base resin in resin synthesis increased the cure slope of vitrification. The cure times taken to reach the vitrification were longer for UMF resins than UF resins and increased with increased melamine levels. The thermal stability and rigidity of cured UMF resins were higher than those of UF resins and also higher for resins with higher melamine levels, to indicate the possibility of bonding particleboard with improved bond strength and lower formaldehyde emission. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 377–389, 2005     

乳化剂对自修复微胶囊合成的影响

以改性脲甲醛树脂为囊壁,以苯乙烯为高分子囊芯,原位聚合法合成了一种全新的自修复微胶囊——改性脲甲醛包覆苯乙烯微胶囊。实验中采用了不同种类的表面活性剂以及阿拉伯树胶与十二烷基苯磺酸钠(DBS)的复配,通过光学显微镜对实验结果进行了检测,分析了乳化剂对微胶囊合成的影响。并对合成的微胶囊采用光学显微镜(OM)观察其形貌并对粒径进行了统计分析。     

平板卧式超滤膜元件的微分方程模型

在平板卧式超滤膜元件结构模型的基础上,建立了膜元件运行的微分方程数学模型．由膜元件运行参数限定了微分方程的边界条件,推导出微分方程组具有唯一解．膜元件运行微分方程模型的建立,为分析膜元件系统的运行提供了数学理论基础．     

观测值延时的UF在SINS中的应用

建立观测信号随机一步延时模型,在此基础上给出Unscented滤波(UF)算法。建立捷联惯导系统(SINS)动基座大方位失准角下的对准模型,将扩展滤波(EF)算法和UF算法应用于SINS动基座初始对准中,分别进行不同延时概率条件下的实验仿真,结果表明,UF算法相对于EF算法具有更高的对准精度和更快的收敛速度。     

BAF/UF/RO联合工艺深度处理印染废水中试

采用中试规模（5m^3／d）的曝气生物滤池／超滤／反渗透联合工艺对棉印染废水二级生化处理出水进行了深度处理。试验结果表明：当进水COD、色度、浊度、电导率分别为308—509mg／L、128—220倍、56—158NTU、5360—6580DS／cm时，相应的出水指标分别为10～20mg／L、〈2倍、〈0．5NTU、48—59DS／cm，该水质可满足印染工艺的要求。     

GAC,UF,RO去除饮用水中氯仿,四氯化碳性能的试验研究

研究了粒状活性炭（ＧＡＣ）,超滤（ＵＦ）和反渗透（ＲＯ）对自来水中氯仿和四氯化碳的去除性能,探讨了ＧＡＣ对氯仿和四氯化碳去除的物理吸附和微生物降解机理。试验发现ＵＦ膜对氯仿和四氯化碳的快速吸附与脱附现象,并讨论了ＲＯ膜对不同浓度氯仿、四氯化碳的去除效果和作用机理。     

铝材电泳涂装中封闭清洗回收系统

介绍铝材电泳涂装后封闭清洗回收系统，在保证清洗质量的前提下，该系统的应用，提高了电泳涂料的回收率；减少了废水排放，节省了处理费用；节约了纯水的用量。并对该系统中主要设备（超滤和反渗透）的透过量的设计计算进行了介绍。     

脲醛树脂制造所用的尿素与甲醛的供应和计量

尿素及甲醛的计量、质量及价格对纤维板的质量及经济效益影响很大,建议购置名牌产品,从大型生产企业定点进货,有条件的单位可考虑使用散装尿素。     

Evaluation of commercial PTFE membranes in desalination by direct contact membrane distillation

In this study, nine flat-sheet commercially available hydrophobic PTFE membranes were used in desalination by direct contact membrane distillation and their characteristics were investigated under different operating conditions including feed temperature, feed flow rate, cold stream flow rate, and feed concentration. Membrane properties, i.e. pore size, thickness, support layer, and salt rejection were also studied. Moreover, membrane module designs including flow arrangements (co-current, counter-current and tangential) for process liquid and depth both on hot and cold sides were tested experimentally. Finally, the long-term performance of the selected membranes for direct contact membrane distillation as a stand-alone desalination process was investigated. The results indicated that increasing feed temperature, hot feed flow rate, and module depth on the cold side led to increase permeate flux. On the other hand, increasing membrane thickness and module depth on the hot side (at constant flow rate) had negative effects on the flux. The highest permeation flux and salt rejection was achieved when the membranes with a pore size of 0.22 μm were used in the cross-current follow arrangement of hot and cold streams. In addition, the requirements for support layer for a successful DCMD process has been extensively discussed.