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1.
导电聚苯胺/聚苯乙烯核/壳结构复合微球的制备   总被引:2,自引:0,他引:2  
通过化学改性对聚苯乙烯微球进行磺化处理,引入亲水性的磺酸基,采用原住聚合的方式,在磺酸根的掺杂下制备了具有核/壳结构的导电聚苯胺/聚苯乙烯复合微球。复合微球中聚苯胺含量为19.3%时导电率约为0.10S/cm,与用聚苯乙烯磺酸本体掺杂的导电率相当。  相似文献   

2.
在以拟薄水铝石胶溶法制备的AlOOH溶胶中加入CeO2粉末,制备物质的量组成为nCeO2:nAl2O3 =1:3的涂覆浆液,并对堇青石蜂窝陶瓷载体进行表面涂覆.利用X射线衍射(XRD)、比表面积(BET)等方法研究了CeO2掺杂对氧化铝涂层的晶相结构、负载量以及比表面积和孔径分布的影响.结果表明,CeO2掺杂抑制了介稳态γ-Al2O3向稳定态α-Al2O3的转变,增加了氧化铝涂层的负载量和比表面积,提高了氧化铝涂层的高温热稳定性.  相似文献   

3.
用掺杂稀土的方法制成了抗热冲击的氧化铝载体。研究了稀土在氧化铝中掺入深度对阻滞氧化铝相变、延缓烧结和生成低表面积化合物的效应。对十种稀土的效应进行了比较。提出一种分两步掺杂的技术,可获得甚为满意的结果,所制得的含镧氧化铝在1000℃热冲击2小时后仍为γ-相,1200℃热冲击2小时后仍为δ—相,而未掺杂的氧化铝在相应温度下分别为γ+δ-相和α-相。这类含镧氧化铝试样在800,1000,1200℃热冲击2小时后比表面积仍可达230,126,28米~2/克,而相应的未掺杂氧化铝分别为150,77,8米~2/克。对掺杂稀土的氧化铝的孔径分布、表面酸度、表面化学活性等作了综合考察,证明它和纯氧化铝没有明显的差异,故认为这类载体可能在催化剂制造工业中有广泛的适应性。  相似文献   

4.
以二价SnCl2无机盐为原料,基于配合物前躯体方法制备了氧化锡及铜离子掺杂氧化锡纳米晶.根据DSC和TG分析结果在550℃对前驱体进行煅烧.运用FTIR、UV-VIS、XRD和TEM/HRTEM等测试手段对两纳米晶材料进行了分析表征.掺杂后掺杂相氧化物分散驻留在SnO2晶粒表面,阻止了SnO2晶粒表面的扩散,从而抑制其晶粒生长.此外,铜离子掺杂使得表面缺陷附近的自由电子能有效的定域化,从而使SnO2纳米晶体系的直接和间接带隙能均向高能方向移动.试验证明以无机盐代替金属醇盐为原料是切实可行的,且配合物前躯体法简单易操作,将有利于产业化.  相似文献   

5.
从阻抑氧化铝的相变、表面化合物的生成和延缓氧化铝的烧结三个方面探讨了氧化铝掺杂镧后改善热稳定性的机理。  相似文献   

6.
用原子力显微镜研究聚苯乙烯胶体颗粒的特性   总被引:2,自引:1,他引:1  
以聚苯乙烯胶体颗粒为研究对象,主要讨论均分散聚苯乙烯胶体颗粒的制备、用原子力显微镜研究样品的各种物性.首先寻找合适的方法合成均分散聚苯乙烯微球,制备较均匀的胶体颗粒:然后用原子力显微镜分别从样品表面微观形貌的直观的三维结构信息,及表面在纳米尺度上表现出来的物理、化学性质进行测试;最后对获得的数据进行分析,并对其性质进行表征.结果表明:无皂乳液法,为制备单分散聚苯乙烯微球的有效方法;通过分析聚苯乙烯颗粒样品表面孔径大小和分布,显示了原子力显微镜在分析样品表面形貌结构方面有其特有的优势,它非常适合用于研究纳米尺度上样品。  相似文献   

7.
制备了Ni^2+离子掺杂的聚苯乙烯阳离子交换树脂,并对其进行碳化处理, 树脂碳化产物的组成和结构,同时还考察了树脂碳化产物作为二次锂离子电池碳电极材料时的电化学性能。实验结果表明:Ni^2+离子掺杂的聚苯乙烯阳离子交换树脂碳化产物与相同条件下处理的未掺杂离子的树脂碳化产物相比,氢、氧含量有所提高,而硫含量则有所降低;N^2+离子掺杂提高了聚苯乙烯阳离子交换树脂脂碳化产物的石墨化程度,并且促进了碳化  相似文献   

8.
改性氧化铝为载体的钯催化剂对甲烷催化氧化作用的研究   总被引:8,自引:1,他引:7  
采用Mg、Mn、Ni、Zr、La、Ce等掺杂离子对氧化铝载体进行表面修饰,发现在改性载体表现形成的物相对添组分PdO的分散状态产生很大的影响,该效应并未通过改变可供分散表面的途径,而是采取了金属-载体相互作用的方式来实现的。变价金属杂质修饰的氧化铝载体表面形成的中间键型对甲烷燃烧反应没有助催作用,而在非变价金属Mg、Zr修饰的样品中的高温稳定的PdO物种,对反应产生了明显的助催效果,这种高温稳定的活性中间体是一种与PdO晶体具有相同的键合类型,具有特殊结构的PdO聚集体。  相似文献   

9.
制备了Ni~(2+)离子掺杂的聚苯乙烯阳离子交换树脂,并对其进行碳化处理,分析了树脂 碳化产物的组成和结构,同时还考察了树脂碳化产物作为二次锂离子电池碳电极材料时的电 化学性能.实验结果表明:Ni~(2+)离子掺杂的聚苯乙烯阳离子交换树脂碳化产物与相同条件下处 理的未掺杂离子的树脂碳化产物相比,氢、氧含量有所提高,而硫含量则有所降低;Ni~(2+)离子掺 杂提高了聚苯乙烯阳离子交换树脂碳化产物的石墨化程度,并且促进了碳化产物中层片石墨 微晶结构的增长和有序排列;Ni~(2+)离子掺杂有效的提高了树脂碳化产物作为锂离子电池碳负极 材料的电化学性能.与未掺杂离子的树脂碳化产物相比,Ni~(2+)离子掺杂的树脂碳化产物组装的 锂离子电池充放电容量平均提高了约20(mA·h)/g,同时还显著降低了电池第一次充放电时的 不可逆性.  相似文献   

10.
以氯甲基化聚苯乙烯为原料,合成了在聚苯乙烯基体和杂环功能基2-巯基苯并噻唑(MBZ)之间引入聚氧乙烯亲水性悬臂的新型螯合树脂,对所合成的树脂进行了元素分析、红外光谱和扫描电镜表征,对比研究了引入悬臂前后树脂对Hg^2+等5种金属离子的静态吸附性能.实验结果表明:经过多步反应,引入亲水性悬臂之后,树脂的表面形貌没有变化,仍保留大孔结构,吸附选择性和功能基的利用率显著提高.  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.
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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

16.
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   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
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   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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