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1.
采用浸浆成型法制备气固分离用SiO_2短纤维陶瓷膜,研究涂膜前后样品的过滤阻力、滤后气体含尘量(VFPM_(2.5))和循环再生性能。对涂膜液的固含量和纤维添加量进行考察,确定适宜的涂膜液制备参数,进而研究浸浆时间和烧成温度对膜过滤性能的影响,通过扫描电子显微镜(SEM)观察样品表面形貌。结果表明:适宜的涂膜液固含量为10%~12.5%,纤维添加量为30%;涂膜过程中,适宜的浸浆时间为60 s,样品的最佳烧成温度为950℃,保温时间为2.5 h;由以上实验条件制备的纤维陶瓷膜过滤效率高且循环再生性能良好。涂膜后样品的孔径明显减小,短纤维完全地覆盖在支撑体表面形成具有3D纤维网络状结构的膜层,膜层厚度为25~30μm。  相似文献   

2.
氧化铝微滤膜的制备及表征   总被引:3,自引:0,他引:3  
该文介绍采用固态粒子烧结法制备管状氧化铝微滤膜的方法 ,研究分散剂用量和悬浮液的稳定性、涂膜时间和膜厚的关系以及烧结温度对孔径分布的影响 ,利用扫描电镜研究膜的微观形貌 ,采用泡压法测定膜的孔径分布。实验结果表明 ,所得的膜具有孔径分布窄的特点 ,平均孔径为 0 .76 μm ,孔隙率为 35 .6 % ,纯水通量为 2 .0 2m3 / (m2 ·h)。  相似文献   

3.
以杏壳为原料,通过碳化法制备了碳膜支撑体,利用泡压法表征了支撑体的孔径分布。对杏壳原料进行预碳化、粉碎、筛分得到碳粉,将碳粉和添加剂混匀挤出成型得到支撑体原膜,经干燥、碳化得到无缺陷碳膜支撑体。实验结果表明,粘结剂用量增加会导致支撑体平均孔径变小,纯水能量减小。随着原料颗粒的减小支撑体平均孔径减小,纯水能量下降。  相似文献   

4.
本研究利用α-Al_2O_3为原料,添加粘结剂、成型助剂、成孔剂,采用注浆成型,通过固态烧结技术制备了不同规格的多孔性微孔膜管。制备的基质管孔隙率在40~50%,平均孔径0.8~2.0μm,微滤层的孔隙率在30~45%,平均孔径0.1~0.5μm,并具有一定的机械强度。文中分析了影响膜管成型的因素及成孔烧结的机制,探讨了成孔剂和烧成温度对膜的结构、孔径、渗透系数、孔隙率的影响,实验发现加入成孔剂可大大提高了膜的渗透性能,是制取大通量膜材的方法之一,同时发现温度是影响膜性能的重要因素,合理的烧成温度与粘结剂、骨科有很大的关系。  相似文献   

5.
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   

6.
渗透汽化性能及结构稳定性是复合膜的重要评价指标。采用纳米划痕技术原位表征分离层与支撑体的界面结合强度。以聚二甲基硅氧烷(PDMS)化合物作为膜材料,详细考察管式多孔陶瓷支撑体粗糙度及孔径对PDMS复合膜界面结合强度及渗透汽化性能的影响。结果表明:陶瓷支撑体粗糙度为1μm,平均孔径为200nm,制备的复合膜结构稳定性及渗透汽化性能最佳,临界载荷为27mN,当进料温度为40℃时,膜对1%丁醇水溶液的通量可达1139g/(m~2·h),分离因子为22。  相似文献   

7.
以杏壳为原料,通过碳化法制备了碳膜支撑体,利用泡压法表征了支撑体的孔径分布。对杏壳原料进行预碳化、粉碎、筛分得到碳粉,将碳粉和添加剂混匀挤出成型得到支撑体原膜,经干燥、碳化得到无缺陷碳膜支撑体。实验结果表明,粘结剂用量增加会导致支撑体平均孔径变小,纯水能量减小。随着原料颗粒的减小支撑体平均孔径减小,纯水能量下降。  相似文献   

8.
多孔阳极氧化铝膜的制备工艺研究   总被引:5,自引:0,他引:5  
王伟  梁淑敏  周淑清 《应用科技》2006,33(4):60-61,64
以草酸为电解液研究了多孔阳极氧化铝膜的制备工艺,采用扫描电子显微镜对多孔氧化铝膜的形貌进行表征.分别讨论了阳极氧化电压和电解液温度对多孔阳极氧化铝膜的形貌及孔径的影响.实验结果表明,当氧化时间为8h时,氧化膜厚度达到最大值85μm.  相似文献   

9.
采用凝胶注模工艺,在陶瓷浆料发泡的基础上,通过有机单体的原位聚合固化制备莫来石泡沫陶瓷.研究了工艺条件对纯单体溶液、发泡和未发泡悬浮浆料等不同体系聚合反应的影响.聚合反应过程的温度变化曲线分析表明,单体溶液或浆料的pH值、初始温度和组成对其聚合反应有显著影响.制备的泡沫陶瓷为开孔贯通泡沫体,体积密度为理论密度的8%-40%,气孔率可达到90%以上,平均孔径范围和孔径分布范围分别为50-300μm和30-800μm显微结构分析表明,泡沫陶瓷平均孔径和孔径分布取决于聚合反应引发时间和泡沫陶瓷体积密度.  相似文献   

10.
以工业级陶瓷片为支撑体,氧化铝溶胶为电泳液,采用电泳沉积的方法制备了氧化铝陶瓷膜。当在30 V的电压条件下电泳3 min,经沉积-干燥-烧结工艺,反复进行3次后,即可得到氧化铝纳滤膜。采用SEM和液-液排除法等手段对纳滤膜进行表征,结果表明,膜厚在50 μm左右,孔隙率为31.51%,平均孔径为3.1 nm,孔径分布为2.88~5.76 nm。性能测试表明,氧化铝纳滤膜对无机污染物和有机污染物均有强的截留作用,且性能较稳定。  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.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

16.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

17.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

18.
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   

19.
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   

20.
The non-orthogonal localized molecular orbital(NOLMO)is the most localized representation of electronic degrees of freedom.As such,NOLMOs are thus potentially the most efficient for linear scaling calculations of electronic structures for large systems.However,direct ab initio calculations with NOLMO have not been fully implemented and widely used,partly because of the slow convergence issue in the optimization of NOLMO.We devel-  相似文献   

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