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1.
为了克服传统有机膜与陶瓷膜的一些不足之处,以TiAl金属间化合物为支撑体,用悬浮粒子烧结法在孔径为10.6um的片状支撑体上制备多孔金属Ni膜。考察了浸浆时间、烧结温度等工艺参数对膜表面形貌和孔径大小、分布等膜性能的影响。结果表明,合适的制膜条件是:浸浆时间为60s,烧结温度为500℃。得到了孔径分布比较窄而且表面比较平整的微滤膜,其平均孔径为0.83μm,膜厚约为30μm。  相似文献   

2.
一种新型的萃取过程--膜分散萃取   总被引:7,自引:1,他引:6  
为研究膜分散萃取的行为和效果 ,采用 30 % TBP-煤油作为分散相 ,去离子水作为连续相 ,SDS作为表面活性剂 ,硝酸为溶质 ,传质方向为从水相到有机相 ,以孔径为0 .2μm的 Al2 O3陶瓷膜为介质进行了研究。研究发现 ,膜分散萃取可以形成均一的液滴 ,萃取效果十分显著 ,级效率在95 %左右。  相似文献   

3.
以氧化石墨烯(GO)掺杂聚偏氟乙烯(PVDF)制备的GO/PVDF平板膜为研究对象,研究膜的过滤特性和过滤阻力分布,并考察不同孔径的膜对造纸废水的处理效果。结果表明:随着GO掺量的增大,膜的亲水性以及抗污染性增强,膜的热稳定性增强。添加2%GO的膜的接触角为63.1°,纯水通量和牛血清蛋白(BSA)通量分别达到595和121 L/(m2·h),对BSA的截留率为74%;BSA溶液过滤过程中表面沉积阻力占主导,物理清洗后,膜的纯水通量恢复率低于55%;化学清洗后,膜的纯水通量恢复率大于96%。大孔径(1和2μm)膜处理造纸废水,因膜孔堵塞,通量迅速衰减,小孔径(0.15、0.3和0.55μm)膜的稳定通量随孔径的增大而增大。  相似文献   

4.
盐泥除盐的膜清洗技术研究   总被引:1,自引:0,他引:1  
针对盐泥悬浮颗粒体系,采用国产无机陶瓷膜,对盐泥除盐膜清洗工艺的可行性进行重点考察,对膜孔径、过程参数对处理效果的影响进行系统研究.结果表明,在ΔP=0.24MPa,v=0.576 m/s,质量浓度为1%,T=35±3℃下,采用孔径为0.2μm的α-Al2O3陶瓷膜清洗盐泥,具有较好的除盐效果.污染膜在0.10 mol/LHNO3溶液中浸泡煮沸约30 min,然后水冲洗,膜通量基本恢复.  相似文献   

5.
该研究采用溶液共混法以硼酸作为交联剂制备PVA-SA水凝胶生物载体,并结合比表面积/孔径分布仪、扫描电镜及傅里叶红外光谱等分析手段对载体进行分析;通过快速排泥法对载体挂膜,考察其在废水处理中的生物活性和处理效果.结果表明,当PVA浓度为7%、SA浓度为1%时,制得PVA-SA水凝胶生物载体具有较好的热稳定性,比表面积为24.233 m2·g-1,平均孔径为60.895 nm,孔隙分布以大孔和中孔分布为主,微孔所占比例比较小.扫描电镜观察显示挂膜前的凝胶球空间网络稳定,有丰富的孔隙结构.挂膜后的凝胶球表面及内部有效富集了大量的微生物,生物活性较好,耗氧速率为8.95μg O2·(min·颗)-1,COD去除率能达到89%,能够作为一种理想的生物载体.  相似文献   

6.
以质量分数为12%的聚间苯二甲酰间苯二胺(PMIA)溶液为纺丝液,采用溶液喷射纺丝技术制备了直径范围为146~532nm的PMIA纳米纤维膜,探讨了面密度对纤维膜孔径结构、透气性、水通量及过滤效率的影响.结果表明,随着面密度的增加,纤维膜的平均孔径、透气量和水通量逐渐降低,过滤效率明显增加,当面密度为22.8g/m2时,纤维膜对2.5μm聚苯乙烯(PS)微球的过滤效率高达99%以上.过滤机理研究结果表明,PS微球很大程度上被拦截在纤维膜表层,膜污染程度较小.  相似文献   

7.
通过比表面积 (BET)、孔径分布 (PD)、DTA- TGA、IR、XRD、TEM等测试手段对Si O2 纳米干凝胶在煅烧过程中的性能变化进行了研究 .结果表明 ,样品的最大比表面积为998m2 / g,最可几孔径为 7nm,在 6 0 0℃以下煅烧时样品具有多孔网络结构 ,结构稳定 ,同时能够将杂质和表面活性剂除掉  相似文献   

8.
乳液模板法是一种制备高度有序多孔材料的重要方法,而膜乳化法则是一种新型的通过膜结构制备乳液的方法.文中提出了一种采用二次膜射流乳化制备单分散乳液模板的方法,平均孔径为0.16 μm和1.5 μm的陶瓷膜分别被作为两次乳化的乳化介质.采用异辛烷/甲酰胺体系为研究对象,嵌段高分子聚(乙二醇)聚(丙二醇)聚(乙二醇)作为乳化剂.实验表明一级膜乳化过程的通量为75.4 L/(m2·h) ,二级膜乳化过程的通量可达到169.9 L/(m2·h).所得单分散乳液模板的平均粒径为1.8 μm,且在10 h内能保持较好的稳定性.  相似文献   

9.
采用悬浮粒子烧结法制备氧化钛-氧化铝复合微滤膜,研究了膜厚度、烧结时间和烧结温度对膜的孔径及其分布的影响.  相似文献   

10.
采用孔径分别为50、200和500 nm的陶瓷膜处理碱性酪蛋白水溶液,考察操作条件及pH对过滤通量和截留率的影响,并研究酪蛋白胶束在不同pH下的聚集行为.结果表明:采用孔径为200 nm的陶瓷膜过滤1 g/L的酪蛋白溶液,在pH=13,操作压差0.10 MPa,膜面流速3.0 m/s条件下,可获得膜通量266 L/(m2·h)和酪蛋白截留率71.8%,综合效果好.酪蛋白的胶束尺寸和黏度随pH的增大而增大.膜过滤通量随pH增大而减小 ;截留率随pH增大而增大.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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