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1.
利用企业的电子陶瓷工艺制备了ZnO掺杂Bi0.5(Na1-x-yLixKy)0.5Ti O3无铅压电陶瓷,研究了ZnO掺杂对该体系陶瓷的介电压电性能与微观结构的影响.X射线衍射结果表明,当ZnO含量小于0.5wt%时,掺杂的ZnO扩散进入了Bi0.5(Na1-x-yLixKy)0.5Ti O3钙钛矿结构的晶格;SEM观察结果表明,少量的ZnO掺杂可以改善该陶瓷的微结构;介电压电性能研究结果表明,当掺杂量较少时,ZnO对该体系陶瓷的介电压电性能有一定的改善,但不明显.  相似文献   

2.
光催化氧化处理垃圾渗滤液研究   总被引:4,自引:0,他引:4  
通过实验,研究分析了不同催化剂(TiO2、ZnO)、pH值、光照时间对垃圾渗滤液光催化氧化的影响,得出:TiO2光催化氧化效果明显优于ZnO的效果,TiO2光催化氧化对COD的去除率为72%;pH值对光催化影响不大,pH=5—9均可;光照时间60min效果最好.  相似文献   

3.
不同衬底材料的ZnO/Si异质结I-V及光电特性   总被引:1,自引:0,他引:1  
采用脉冲激光沉积(PLD)技术和微电子平面工艺,用不同表面掺杂的Si作为衬底制备了ZnO/Si异质结,并且以p-Si(p-)为衬底制备了ZnO(含Mn0.2%)/Si异质结、包含SiC缓冲层的ZnO/SiC/Si和ZnO(含Mn0.2%)/SiC/Si结构,测试了样品的XRD曲线、I-V特性曲线和P-E(光电响应)特性曲线.结果发现ZnO/n-Si结有很低的反向暗电流,SiC缓冲层能提高反向击穿电压,ZnO/p-Si(p )异质结能有较强的光电响应,ZnO/n-Si(n-)更适合作为大波段区间的光探测器.还发现波长470,480,490nm处类似于声子伴线的光谱结构.  相似文献   

4.
采用脉冲激光沉积(PLD)技术和微电子平面工艺,用不同表面掺杂的Si作为衬底制备了ZnO/Si异质结,并且以p-Si(p-)为衬底制备了ZnO(含Mn 0.2%)/Si异质结、包含SiC缓冲层的ZnO/SiC/Si和ZnO(含Mn 0.2%)/SiC/Si结构,测试了样品的XRD曲线、I-V特性曲线和P-E(光电响应)特性曲线.结果发现ZnO/n-Si结有很低的反向暗电流,SiC缓冲层能提高反向击穿电压,ZnO/p-Si(p+)异质结能有较强的光电响应,ZnO/ n-Si(n-)更适合作为大波段区间的光探测器.还发现波长470,480,490 nm处类似于声子伴线的光谱结构.  相似文献   

5.
在经典衍射理论中,不产生Si(200)反射。对此,作者通过理论和实验进行了证实。由于Si晶体中电子云分布的非对称性,会出现Si(200)衍射峰。论述了Si(200)衍射在实际工作中的应用。  相似文献   

6.
氧离子束辅助激光淀积生长ZnO/Si纯ZnO相的研究   总被引:1,自引:1,他引:0  
通过X射线光电子能谱(XPS)深度剖析方法对ZnO/Si异质结构进行了分析。结果表明:用该法可生长出正化学比的纯ZnO相,脉冲激光淀积(PLD)法生长ZnO/Si样品时氧离子束辅助(O^ -assisted)是必要的。  相似文献   

7.
用sol-gel工艺直接在Pt/Ti/Si O2/Si衬底上制备出了a轴择优取向(α(100)=62%)和高c轴取向(α(100)=96%)的Bi3.15Nd0.85Ti3O12(BNdT)薄膜.发现BNdT薄膜的铁电介电性能强烈依赖于晶粒取向.a轴择优取向BNdT薄膜的2Pr和εr值最高,分别为65μC/cm2和343(100kHz处);随机取向薄膜的2Pr和εr值为34μC/cm2和331;而高c轴取向薄膜的2Pr和εr值最低,分别为23μC/cm2和218.上述结果表明,BNdT的自发极化矢量靠近a轴.纯a轴取向BNdT薄膜的2Pr值可估算为84μC/cm2.  相似文献   

8.
采用溶胶-凝胶(Sol-Gel)旋涂法在Si(100)和熔石英衬底上制备ZnO薄膜,利用X射线衍射(XRD)、光致发光谱(PL)等手段分析得到ZnO薄膜的晶体结构和发光特性.结果表明,在Si(100)衬底上制备的ZnO薄膜呈现沿各个晶面自由生长的特性,而熔石英衬底上制备的样品呈现沿c轴择优取向生长的特性.  相似文献   

9.
磁控溅射法生长ZnO薄膜的结构和表面形貌特性   总被引:1,自引:0,他引:1  
采用射频磁控溅射方法,在Si(111)和玻璃基片上制备ZnO薄膜.研究衬底温度和基片类型对薄膜结构、表面形貌的影响.结果显示,所有ZnO薄膜沿c轴择优生长,同种基片类型上生长的薄膜,随着衬底温度升高,(002)衍射峰强度和表面粗糙度增高;相同衬底温度下生长的ZnO薄膜,Si基片上制备的薄膜(002)衍射峰强度和表面粗糙度小于玻璃片上的.基片类型影响薄膜应力状态,玻璃片上制备的ZnO薄膜处于张应变状态,Si基片上的薄膜处于压应变状态;对于同种基片类型上生长的ZnO薄膜,衬底温度升高,应力减小.Si衬底上、300℃下沉积的薄膜颗粒尺寸分布呈正态.  相似文献   

10.
Si60团簇与Si(111)面碰撞的紧束缚分子动力学模拟   总被引:1,自引:0,他引:1  
利用普适的紧束缚分子动力学模拟研究在不同入射条件下Si60团簇与Si(111)面的碰撞机理,结果表明Si60分子是“非弹性分子”,入射角度对碰撞结果有重要影响,Si60分子易和Si(111)面发生化学反应,其保持结构特性吸附于Si(111)表面的能量域值在50~80eV之间.  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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