共查询到20条相似文献，搜索用时 703 毫秒
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为制备高质量的纳米晶硅薄膜,采用等离子体化学气相沉积方法,以硅烷、高纯氢为源气体,氢稀释率保持在98％,衬底温度200℃,反应气压100 Pa,沉积时间60 min,在射频频率分别为13.56、54.24 MHz下合成了纳米晶硅薄膜.利用Raman光谱和X射线衍射技术分析了样品,结果表明,高激发频率可促进薄膜从非晶硅到纳米晶硅的转化,有利于提高薄膜的晶化率,且晶粒具有各种晶体取向,没有出现择优生长.当激发频率从13.56 MHz升高到54.24 MHz时,晶化率相应从9％提高到72％. 相似文献
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通过脉冲激光沉积方法在1.3Pa氧氛围,100-500℃衬底温度,Si(111)衬底上成功地制备了ZnO薄膜,我们用X射线衍射(XRD)谱,原子力显微镜(AFM),透射电镜(TEM)对其表面形貌和结构进行了测试和分析。通过测试分析得知,这些ZnO薄膜在生长温度400℃时能够获得较好的晶体结构,薄膜表面平整,晶粒均匀。 相似文献
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用电子束蒸镀方法在250℃~450℃的衬底温度范围内在单晶Si衬底(111)晶面上成功生长了Zn0.85Co0.14Cu0.01O薄膜,并研究了衬底温度对薄膜质量的影响,结果表明:当衬底温度为400℃时,外延膜取向性最好,且其(002)衍射峰半高宽最窄,仅为0.408°。 相似文献
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采用射频磁控溅射法在不同衬底温度下沉积了一系列ZnO和ZnO∶ Mn薄膜.结合X射线衍射谱和扫描电子显微镜,分析了不同温度条件下的ZnO和ZnO∶ Mn薄膜的结构特性.结果显示:ZnO和ZnO∶Mn薄膜均呈现出显著的(002)定向生长特征,与ZnO的(002)衍射峰相比,相应条件下生长的ZnO∶ Mn(002)衍射峰均向小角度偏移,这主要是由于大离子半径的Mn2+替代了Zn2+的结果.同时随着衬底温度的升高,薄膜形貌得到明显改善,晶粒尺寸呈现减小趋势. 相似文献
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用电子束蒸镀方法在250℃～450℃的衬底温度范围内在单晶Si村底(111)晶面上成功生长了Zn0.85 Co0.14 Cu0.01O薄膜,并研究了衬底温度对薄膜质量的影响,结果表明:当衬底温度为400℃时,外延膜取向性最好,且其(002)衍射峰半高宽最窄,仅为0.408°. 相似文献
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用电化学阳极氧化法制备了一定孔隙率的多孔硅样品,然后用脉冲激光沉积法以PS为衬底生长一层ZnS薄膜.用X射线衍射仪、扫描电子显微镜和荧光分光光度计分别表征了ZnS薄膜的结构、形貌和ZnS/PS复合膜的光致发光性质.XRD结果表明,制备的ZnS薄膜沿β-ZnS(111)方向择优生长,结晶质量良好,但衍射峰的半峰全宽较大;SEM图像显示,ZnS薄膜表面出现一些凹坑,这是衬底PS的表面粗糙所致.室温下的光致发光谱表明,沉积ZnS薄膜后,PS的发光峰蓝移.把ZnS的蓝绿光与PS的橙红光叠加,在可见光区450~700 nm形成了一个较宽的光致发光谱带,ZnS/PS复合膜呈现较强的白光发射. 相似文献
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金刚石薄膜的制备与热丝温度、衬底温度、工作室压强及反应气体浓度有关,氢原子具有抑制石墨生长的作用,衬底的表面处理对金刚石薄膜的生长有很大影响。本文还试图用晶体生长和相变理论解释金刚石薄膜的生长过程。 相似文献
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《嘉应学院学报》2017,(8):31-36
在低温条件下利用Al诱导结晶在绝缘衬底上生长高晶体质量的多晶Ge薄膜.使用厚度为1~10 nm的Ge插入层可以改善多晶Ge薄膜的生长条件,Ge插入层放置在Al层的下方.使用Ge插入层的目的是提高Ge原子在Al层中的超饱和浓度.Ge插入层可以在275°C的低温下产生Al诱导结晶.Ge插入层可以导致较高的成核率,厚度大于3 nm的Ge插入层可以产生大量的Ge晶体小颗粒,厚度为1 nm的Ge插入层可以促使多晶Ge薄膜快速生长,并产生直径为100μm的Ge晶体大颗粒.从电子背散射衍射(EBSD)测量中可知,Al诱导结晶生长的多晶Ge薄膜具有良好的(111)晶向. 相似文献
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成桢 《西安文理学院学报》2015,(1):60-62,83
采用射频磁控溅射法在玻璃衬底上制备掺镁氧化锌薄膜,利用SEM(扫描电镜)、XRD(X射线衍射)和椭偏仪等设备研究薄膜的表面形貌、成分、结构和厚度.结果表明,溅射功率没有对薄膜的生长方向产生较大影响,当溅射功率在40 W到100 W之间变化时,随着溅射功率的增大薄膜的结晶状况变好,晶粒尺寸变大,薄膜的厚度增加. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献
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The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献