共查询到20条相似文献，搜索用时 140 毫秒
1.
采用等离子体增强化学气相沉积技术制备了硼掺杂氢化非晶硅薄膜,然后经过不同温度的热退火处理,获得硼掺杂纳米硅薄膜．结果表明,退火温度为700℃时,样品中开始有纳米晶形成,随着退火温度的增加,在1000℃时,薄膜的晶化率达到77％,晶粒大小为3．9nm．退火温度低于600℃时,光学带隙随着退火温度的升高而变窄,高于600℃... 相似文献
2.
lintroductionThedetectionofinfl.aredandvisiblelightradiationbysuperconductingfilmsisawell-knownphenomenon.Ithas4beenknownthatinconventionalsuperconductors,incidentlightisreflectedfi.omthesuperconductorsurfaceasaresultoftheplasmaoscillationoffi.eeelectrons… 相似文献
3.
介绍了以熔盐法制备珠光颜料用片状氧化铁的最佳制备条件的探讨过程,通过在不同条件如熔盐种类、熔盐用量、煅烧温度和煅烧时间下进行合成,并使用光学显微镜对产品形貌和尺寸进行观察,从而推断出助熔剂法合成片状氧化铁的最佳条件.通过研究发现,在采用Na2SO4＋K2SO4作为复合熔盐,并且熔盐用量与三氯化铁的摩尔比为5的条件下制备前驱体,在1 100℃下煅烧4 h,可得到平均粒径约为20μm,表面平整,形貌良好的六角形片状氧化铁晶体.并对制备的片状氧化铁进行了包覆二氧化钛应用尝试,表明该法制备的片状氧化铁满足珠光颜料的要求. 相似文献
4.
在半导体大功率激光器的各种关键技术中,散热问题的解决是一个极其关键的技术。在管芯焊接的地方产生的热流量大约为1KW/cm2。这种热负载是限制激光器正常工作的关键因素。文章分析了半导体激光器的发热因素,并对了几种常见的热沉类型进行了分析研究。 相似文献
5.
R. Srinivasan 《Resonance》1997,2(6):6-14
In part 2 of this series we dealt with the3He cryostat. By pumping on liquid3He bath a temperature down to 0.3 K can be attained. To reach still lower temperatures in the milli-Kelvin region one uses
a dilution refrigerator. In this part the principles of operation of a dilution refrigerator will be described. 相似文献
6.
郝正同 《绵阳师范学院学报》2010,29(5):18-21
采用基于第一性原理的密度泛函理论赝势平面波方法,对NaSi和KSi的电子结构进行了理论计算,能带结构计算表明NaSi是一种间接带隙半导体,禁带宽度为1.32eV;KSi是一种准直接带隙半导体,禁带宽度为1.42eV;并详细讨论了NaSi和KSi在费米面附近的价带与导带的电子态密度。 相似文献
7.
氧化锌是一种宽禁带的半导体材料,它在太阳能电池、气体传感器等各种光电子器件中有广泛的应用前景.本文用溶胶-凝胶法制备ZnO溶胶,再甩膜在石英基片上,最后经微波加热而获得ZnO薄膜.分别用原子力显微镜、分光光度计和荧光谱仪研究不同厚度薄膜的表面形貌和光学性质.实验结果表明:制备薄膜随着薄膜厚度的增加,薄膜的生长模式由层状生长向岛状生长转变;所有薄膜在可见光范国内的透射率都超过65%;样品发光特性良好. 相似文献
8.
We have developed an experimental setup that has been proven suitable for the study of photoresponse of high T
c superconductors. The distinguish feature of this experimental setup lies mainly in the data acquisition system which is equipped
with computer as well as the IEEE-488 interface bus, which ensures the accuracy to experimental results. Using the experimental
setup, the optical response to laser radiation in high-T
c superconductors has been examined, both of bolometric effect and nonequilibrium optical response are revealed.
The project was supported by the National Natural Science Foundation of China 相似文献
9.
构建了CdS插层层状BiOCl晶胞（CdS-BiOCl）。基于第一性原理对CdS-BiOCl的结构进行了优化计算,在此基础上,计算并分析了 CdS-BiOCl 的电子结构以及光学性质。结果表明,在 CdS-BiOCl 中,Cd同时与两个Cl、两个S原子形成共价键而致a、b轴缩短,c轴拉长;与BiOCl相比,CdS-BiOCl为直接带隙半导体,价带顶因S3p电子参与杂化而提升并致带隙变窄,所有光学性质均发生红移,其峰值均有所降低。 相似文献
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11.
Bruno Giordani Michael J. Boivin Bikayi Opel Diawaku “Noah” Dia Nseyila Roger E. Lauer 《International Journal of Disability, Development & Education》1996,43(1):5-24
There is a continuing need for formalised assessment procedures that can be adapted for group comparisons across diverse cultures to facilitate school and occupational placement, as well as to evaluate the effectiveness of nutritional, education, and medical intervention programs. This study used a direct translation of the Kaufman Assessment Battery for Children (K‐ABC) to evaluate 130 Zairian primary school children. The distinction between Sequential Processing and Simultaneous Processing abilities on the K‐ABC was generally found to be valid in this sample. The K‐ABC also discriminated effectively among grade levels, differences in health and family environment indicators, and tribal membership. Reasonable test‐retest correlations for the K‐ABC global scales were also found with a subsample of the children. The Zairian children's K‐ABC scores, particularly for the Simultaneous subtests, were markedly lower than the American normative sample. Education and experiential factors inherent in the sub‐Sahara environment may put these children at a significant cultural disadvantage in terms of the skills required for successful completion of K‐ABC items. 相似文献
12.
The structural characteristics and optical and electrical properties of molecular-beam-epitaxy (MBE) grown ZnS0.8Se0.2 thin films on indium-tin-oxide (ITO) glass substrates were investigated in this work. The X-ray diffraction (XRD)results indicated that high quality polycrystalline ZnS0.8Se0.2 thin film grown at the optimized temperature had a preferred orientation along the (111) planes. The transmission electron microscopy (TEM) cross-sectional micrograph of the sample showed a well defined columnar structure with lateral crystal dimension in the order ofa few hundred angstroms. Ultraviolet (UV) photoresponsivity as high as 0.01 A/W had been demonstrated and for wavelengths longer than 450 nm, the response was down from the peak response by more than 3 orders of magnitude. The thin ZnS0.8Se0.2 photosensor layer, with a wide energy gap and anisotropic electrical property, makes a transmission UV liquid crystal light valve ( LCLV) with high resolution feasible. 相似文献
13.
针对半导体激光器所发激光束偏振性差、发散角大的特点，提出了一种用中间拖孔的平面镜代替通常所用分束片的方法，来达到分离光束的目的，并且与分束片相比，光学效率可得到明显提高． 相似文献
14.
INTRODUCTION Liquid crystal light valves (LCLV) are devices whose function is to convert an input image pos-sessing specific wavelength, intensity and coher-ence to an output image in which some or all of these parameters are varied (Efron et al., 1985). Therefore, they can be used as image amplifiers for large screen projection display, image wavelength converters and incoherent-to-coherent image converters for optical data processing and correlation. The appli-cation potentialities ar… 相似文献
15.
卢卯旺 《湖南科技学院学报》2006,27(11):156-159
研究了一般的磁调制半导体纳米体系中电子自旋输运性质,其可以通过在半导体异质结表面沉积具有任意磁化方向的铁磁条带形成。通过对真实InAs材料系统的计算,发现这种系统具有很强的电子自旋极化效应,其自旋极化度在共振时超过80％。因此,我们的系统可以用于电子自旋过滤器。 相似文献
16.
文章提出了一种新的研究外光反馈半导体激光器动力学行为的方法,利用Simulink仿真软件建立可视化模型模拟了弱反馈至中等反馈下外光反馈半导体激光器的动态特性,结果表明弱反馈下系统处于周期态,增加反馈量系统的输出由周期态进入混沌态.并对用高频电流注入(HFI)技术控制外光反馈半导体激光器的混沌进行了模拟研究.与基于常规高级程序设计语言的计算机模拟技术相比,该方法避免了传统意义上的复杂算法编程和调试过程,可以方便的改变模型参数并观察到相应的模拟结果. 相似文献
17.
岳喜成 《南阳师范学院学报》2004,3(12):28-31
离子注入聚合物(在一定的能量和一定的剂量)，可引起聚合物电导率增加几个到十几个数量级。利用这个特性，可制作导电图样，制作连线，制作P型半导体材料和N型半导体材料，制作P-N结，制作二维和三维集成电路互连接。离子注入聚合物还使聚合物的颜色加深，光吸收增加，可制作有机太阳能电池。 相似文献
18.
This study extends previous environmental education research on gender differences by investigating the gender gap between boys' and girls' sustainability consciousness. The issue of whether the gender gap in environmental education can be identified also in sustainability education is addressed. It has been suggested that Education for Sustainable Development (ESD) is a teaching approach that could play a key role in diminishing the gender gap. However, the possible gender-specific effect of an ESD-oriented teaching approach is empirically untested. A survey instrument was used to detect the hypothesized gender gap in students' sustainability consciousness on a sample of 2,413 Swedish students aged 12–19. Findings reveal a gender gap in students' sustainability consciousness. The gender gap increases throughout the age span and is amplified in ESD-oriented schools. 相似文献
19.
Research progress of transparent conducting ZnO:Al(ZAO)films 总被引：1，自引：0，他引：1
Owing to both of its high carrier concentration and large band gap,ZnO:Al(ZAO)films which is an n-type degenerate semiconductor,exhibits low resistance and high transmittance in the visible range.This work studies the crystal structure,optical and electrical properties and preparation methods of ZAO films,and discusses the existing problems and application prospective of ZAO films. 相似文献
20.
掺镍镁铝尖晶石电子和光学性质的理论计算 总被引：1，自引：0，他引：1
采用密度泛函理论的平面波赝势方法（PW—USP）和广义梯度近似（GGA）,对替代式0．086％摩尔浓度掺杂的镁铝尖晶石（Ni：MgAl2O4）的电子和光学性质进行了计算．研究结果表明掺镍镁铝尖晶石是具有2．94eV的窄带隙半导体材料．镍掺杂具有使镁铝尖晶石在费米面附近产生杂质能级,导致光学带隙明显减小的特殊作用．通过分析掺杂晶体的光学性质发现,由于杂质镍的引入,使得可见光及近红外光谱区的吸收明显增强,而这归因于镍3d电子t2g和eg轨道间的d-d跃迁,结果与实验符合较好． 相似文献