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1.
研究了用水热法制备纳米ZrO2-TiO2复合氧化物微粉。制备了ZrO2(C)-TiO2(A)。ZrO2(C)-TiO2(R),ZrO2(T)-TiO2(A),ZrO2(T)-TiO2(R)四组纳米复合氧化物及无定形的复合Zr-Ti水合氧化物。研究了它们的相变和可烧结性。经1400℃烧结10h得到了具有95%理论密度的ZrTiO4陶瓷。  相似文献   

2.
以H2TiO3为原料,经过TiO(NO3)2水解的放大实验,制备了金红石型TiO2纳米粒子,通过X射线衍射(XRD)、透射电镜(TEM)和比表面吸附(BET),对纳米粒子的结构、形貌、粒径进行了分析和表征,结果表明,粒子的平均粒径在11nm左右,晶型为金红石型,粒子分布较松散,部分颗粒呈纤维状排列。  相似文献   

3.
铝热法合成TiB_2-Al_2O_3系陶瓷原料反应机理   总被引:1,自引:0,他引:1  
通过Al,B2O3和TiO2体系的热力学分析指出了铝热法合成TiB2的可能性.通过各种不同条件下反应过程的差热实验、X射线衍射等实验分析,对该体系的反应机理有了较系统深入的认识,得出:利用Al,B2O3和TiO2(锐钛砂)在氩气中以较低的温度可合成出较纯的TiB2及Al2O3陶瓷原料.  相似文献   

4.
TiO2纳米薄膜和TiO2/ZnFe2O4纳米复合薄膜的光学性能研究   总被引:6,自引:0,他引:6  
用磁控溅射方法制备了TiO2 纳米薄膜和TiO2/ZnFe2O4 纳米复合薄膜,研究了不同温度热处理和不同含量纳米铁酸锌对纳米TiO2 薄膜光学性能的影响。研究结果表明:用磁控溅射方法制备的纳米薄膜的厚度和晶粒尺寸均匀,并且随着热处理温度的升高而增大,掺杂纳米ZnFe2 O4后TiO2 纳米薄膜的晶粒尺寸略有减小。XRD 研究发现TiO2/ZnFe2O4 纳米复合薄膜由非晶相向锐态矿相转变的温度高于纳米TiO2 薄膜。TiO2 纳米薄膜和TiO2/ZnFe2 O4 纳米复合薄膜的光吸收边都随着晶粒尺寸的降低而发生蓝移,在相同热处理条件下,掺杂纳米ZnFe2 O4 后,纳米TiO2薄膜的光吸收边发生了较大范围的红移,红移量随着掺杂量的增加而增大。通过热处理和掺杂纳米ZnFe2O4 可以实现对纳米TiO2 薄膜光吸收边大范围的调制。  相似文献   

5.
TiO2/BMI树脂固化反应及热性能研究   总被引:3,自引:0,他引:3  
利用热分析技术测定了纳米TiO2共混改性双马来酰亚按(BMI)树脂体系的固体反应参数,考察了固化条件与玻璃化温度之间的关系及纳米TiO2对固化树脂高温热分解性能的影响。研究结果表明,树脂中引入纳米TiO2,降低了固化反应活化能和树脂固化后处理温度,改善了BMI树脂的加工性能;树脂在N2中的超始热分解温度降低,但不改变热氧分解温度;TiO2/BMI固化树脂玻璃化温度高达302℃,热分解温度达420℃  相似文献   

6.
液相沉淀法制备TiO_2超微粉末的影响因素分析   总被引:8,自引:0,他引:8  
利用TiCl4溶液和(NH4)2CO3饱和液反应生成Ti(OH)4沉淀,经洗涤、过滤、干燥、煅烧后制得TiO2超微粉末。根据成核生长的热力学和动力学原理,深入研究分析了共沉淀时温度、pH值、滴定速度和陈化时间对Ti(OH)4粒度的影响。研究结果表明,温度、pH值、滴定速度的影响较为突出,陈化时间的影响较小,煅烧温度对最终产品粒度和性能的影响是十分重要的,实验得出最优制备条件  相似文献   

7.
报道了TiCl4.2「C6H8O」(1);TiCl4.2「C8H11N」(2);TiCl4.2「O(CH2)4CH2」(3).TiCl4.2「C6H7N」(4)TiCl4.2「C5H5N」(5);TiCl4.2「C4H89O2」(6)催化双环戊二烯开环移位聚合反应并对6个影响因素进行了讨论,由此得到优化的反应条件。  相似文献   

8.
本实验在醇盐水解法制备纳米材料的基础上,重点研究了液相一步成形金红石纳米 TiO2有合成方法及条件,制备出的超细粉经电镜检测,粒径在 20~100nm之间。并且证明 PH值对改变 TiO2粉末粒米粒径有直接的影响。  相似文献   

9.
报道了TiCl4·2[C6H8O](1);TiCl4·2[C8H11N](2);TiCl4·2[O(CH2)4CH2](3);TiCl4·2[C6H7N](4);TiCl4·2[C5H5N](5);TiCl4·2[C4H8O2](6)催化双环戊二烯开环移位聚合反应并对6个影响因素进行了讨论,由此得到了优化的反应条件。  相似文献   

10.
以自制高纯TiO2和高纯H2为原料,采用H2还原法制备高纯Ti2O3(纯度>99.99%).研究了还原温度、H2流量、TiCl4浴温、TiO2在恒温区中的位置对还原过程和Ti2O3产品质量的影响,摸索出了制备高纯Ti2O3的工艺条件.采用本工艺制备的Ti2O3,其纯度及批量均达到目前国内领先水平.  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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