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1.
微波酸化K2Ti4O9,正十二胺微波胺基化改性H2Ti4O9,获得正十二胺柱撑的层状钛酸材料.研究了其作为吸附剂,pH、初始染料质量浓度、吸附剂用量等因素对直接湖蓝5B偶氮染料吸附的影响,确定最佳条件.研究结果表明:微波法改性钛酸钾材料,具有良好的吸附性能;pH为2~4,脱色时间为40min,吸附剂用量为1g/L,温度为40℃时饱和吸附量最大,达到1333mg/g,吸附等温式能较好地符合Langmuir和Freundlich方程模型参数.  相似文献   

2.
采用固相法合成层状化合物K0.81Li0.27Ti1.73O4,考察不同原料配比、反应时间及反应温度等条件对其氢离子交换反应和有机胺插层剥层反应的影响.结果表明:在0.1~14mol/L的HNO3溶液中K0.81Li0.27Ti1.73O4均可以通过氢离子交换生成H1.08Ti1.73O4·H2O固体钛酸,若反应温度高,则产物容易转变成TiO2.合适的氢离子交换条件是:室温下浸泡4~7d,n(HNO3)∶n(KLiTiO)=10~20,c(HNO3)=1~10mol/L.在正丙胺(n-PA)和正丁胺溶液中H1.08Ti1.73O4·H2O均可以进行插层剥层反应.反应温度高和有机胺与H1.08Ti1.73O4·H2O的物质的量比过小都容易使生成物转变成TiO2相.理想的插层剥层反应条件为:120℃,反应1d,n(n-PA)∶n(HTiO)=20~100.  相似文献   

3.
离子交换法可控合成四钛酸钾衍生物   总被引:4,自引:1,他引:4  
利用四钛酸钾(K2Ti4O9)离子交换平衡热力学模型预测了获得K2Ti4O9纯相衍生物的最优条件,并以K2Ti4O9晶须为前驱体,以目标产物的固相Ti与K摩尔比为控制目标,通过调节离子交换过程中溶液平衡pH值和用K+选择性电极控制液相K+浓度,成功合成出纯相的水合四钛酸H2Ti4O9*1.2 H2O、TiO2 晶须、K2Ti8O17晶须、K2Ti6O13晶须,用实验验证了预测的准确性.同时实验结果表明,只要控制了离子交换中间产物的固相化学组成,就可以控制最后产物的形式,初步探索了反应过程中组成和结构的关系.  相似文献   

4.
采用纳米级TiO2为原料,通过固相反应法成功制备了超细层状钛酸钾(K2Ti4O9),并与微米级TiO2为原料制备所得产物相比较,以XRD、TEM、TG等表征手段考察了超细层状钛酸钾的酸交换、烷基胺嵌入特性.发现超细层状钛酸钾有利于酸交换和嵌入反应的进行,同时发现了超细层状钛酸钾的剥离特性,剥离所得纳米级片层可以制备静电组装纳米TiO2多层膜.  相似文献   

5.
通过正硅酸乙酯(TEOS)与钛酸正丁酯(Ti(OC4H9)4)间的醇解反应和溶胶-凝胶法制备了一系列无机-有机杂化材料,并观察了Cu^2+的浓度、体系的pH值等参数对Cu^2+吸附性能的影响.结果表明:随着杂化材料中钛含量的增加,它们的比表面积随之增大.Cu^2+吸附实验表明:该类杂化材料确实能够吸附Cu^2+,而且不同比例的Si/Ti杂化材料对Cu^2+的吸附能力不同.因此该类杂化材料能够用于废水中Cu^2+的分离和回收,所以在废水处理等环境保护方面具有潜在的应用价值.  相似文献   

6.
以醋酸钾(CH3COOK)、钛酸四丁酯(Ti(OC4H9)4)、无水乙醇和柠檬酸等为原料,采用柠檬酸配位燃烧法合成钛酸钾系列碳黑氧化催化剂(DOC)K2Ti2O5。利用X线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)表征K2Ti2O5的晶相及表面形貌;利用程序升温反应(TPR)考察老化时间、K2Ti2O5与碳黑颗粒的接触方式、焙烧温度、尾气中SO2和水蒸气含量、重复使用等因素对K2Ti2O5催化活性的影响。结果表明:K2Ti2O5催化活性较高,起燃温度低至280℃,峰值温度为322℃,催化活性在同类活性金属钛氧化物中最好,并且具有良好的重复使用稳定性及抗SO2和水蒸气稳定性。  相似文献   

7.
采用真空熔融缓冷方法合成了单相β-Zn4Sb3化合物,并通过水解钛酸四丁酯(TBOT)制备了Ti O2/β-Zn4Sb3复合材料。采用放电等离子(SPS)烧结获得了致密的块材样品。研究了Ti O2质量分数对复合材料热电性能的影响规律。结果发现,随着Ti O2质量分数的增加,材料的Seebeck系数升高,电导率和热导率均...  相似文献   

8.
四钛酸钾(K2Ti4O9)拥有层状结构,具有优良的化学性质和较大的实用价值.选择Ti2 AlN为原料,将其分散在一缩二乙二醇溶液中,借助在氩气气氛中加热混合物,通过溶剂热法制备了K2 Ti4 O9粉体;探讨了反应温度、通气速率和反应时间对反应产物结构的影响;利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(...  相似文献   

9.
以层状钛酸盐K2Ti4O9/K2Ti6O13/K4TiO4复合物为钛源,通过质子交换、插层和剥离等化学反应,得到了含H2Ti4O9/H2Ti6O13/H4TiO4纳米片的胶态溶液.向上述胶态溶液分别加入NH4F、HCl、H2O2、NH3·H2O等形貌控制剂,通过水热反应,制备了不同晶型、不同形貌的TiO2纳米晶.研究表...  相似文献   

10.
以十二胺(DDA)为模板剂,正硅酸四乙酯(TEOS)为硅源,以硝酸铬(Cr(NO3)3·9H2O)为铬源,钛酸四丁酯(TBOT)为钛源,偏铝酸钠(NaAlO2)为铝源,在一定条件下反应,分别制备了含杂原子Cr,Ti和Al的介孔HMS分子筛.采用粉末X-射线衍射(XRD)、紫外可见漫反射光谱(UV-Vis)、N2吸附—脱附及透射电镜(TEM)等手段对杂原子HMS分子筛进行了表征.XRD结果表明,Cr,Ti和Al杂原子分别嵌入到HMS分子筛骨架;N2吸附—脱附的孔径分布及TEM结果表明杂原子介孔分子筛孔径集中在4nm左右并具有蚯蚓状的孔道结构.  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.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<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   

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