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1.
室温条件下 ,用离子束外延设备制备 ( Ga,Gd,As)样品 ,X射线衍射 ( XRD)结果表明除了 Ga As衬底峰 ,没有发现其他新相的衍射峰。俄歇电子能谱 ( AES)分析了样品中元素随深度的变化 ,不同样品中元素的分布有着不同的特点。并运用原子力显微镜 ( AFM)研究了样品表面的形貌特点 ,表明样品表面的粗糙度与 Gd注入过程中在样品表面沉积的多少有关。运用交变梯度磁强计 ( AGM)对薄膜进行磁性分析 ,结果表明有的样品在室温条件下出现铁磁性 ,但金属钆本身具有室温铁磁性 ,因而需要进一步分析。  相似文献   

2.
采用水热法在低温合成了铋层状钙钛矿结构Bi_(3.15)Nd_(0.85)Ti_3O_(12)(BNdT)纳米材料,利用X-射线衍射(XRD)、扫描电子显微镜(SEM)表征产物的晶相和形貌,研究了反应温度和聚乙烯醇(PVA)对水热合成BNdT纳米结构的影响,运用X-射线光电子能谱(XPS)对BNdT纳米结构的化学组分和元素价态进行了表征.结果表明,反应温度和PVA对水热合成BNdT纳米结构的形貌有较大影响;XPS研究显示BNdT纳米结构的表面存在氧空位和轻微的Bi过量.  相似文献   

3.
以金属锌( Zn)和铝( Al)为靶材采用射频( RF)反应共溅射技术在低温( 2 0 0℃)玻璃衬底上沉积了铝掺杂氧化锌( Zn O∶Al)薄膜.运用扫描电子显微镜( SEM)、能量色散X射线谱( EDX)、表面轮廓仪(α- Step)、X射线衍射( XRD)和双光束紫外-可见光谱仪( U V- VIS)等分别对沉积样品的表面和断面的形貌结构、组成成分和光学特性进行了分析表征.研究了反应气体氧与氩流量比( O2 / Ar)和RF溅射功率对沉积样品的生长速率、结构特征和光电学性质的影响.结果表明,薄膜的成长速率强烈依赖于RF溅射功率,而薄膜的结构形貌和成分的化学配比则主要由反应气体流量比O2 / Ar  相似文献   

4.
用电子束蒸镀和二极直流溅射方法分别制备了钴铬垂直磁化薄膜。1)用VSM及X射线薄膜磁化强度取向摆动曲线的Δθ50等方法做了磁性等测量,结果表明蒸镀和溅射两种方法都能制备出优质钴铬垂直磁化薄膜;2)对Co-Cr垂直磁化薄膜的成分分布及微观形貌用高分辨透射电镜作了晶粒形貌、选区衍射和纳米束斑的能谱分析等研究。其中成分分布结果表明晶界处钴的集聚偏多,而非国际上流行的铬偏多;3)用STM作了晶粒形貌及表面起伏曲线,用AFM、MFM(磁力显微镜)分别做了同一区域晶粒形貌和相应磁畴结构的比较,实验都获得了很好的结果。钴铬固溶体薄膜是典…  相似文献   

5.
大气悬浮颗粒物的电镜观察   总被引:12,自引:0,他引:12  
利用电镜观察城市大气中悬浮颗粒污染物的形貌特征及成分分析是近年来环保领域的一个重要研究手段 ,有效辨认污染源对目前开展空气质量预报有十分重要的意义[1] 。本文运用扫描电镜及X射线能谱仪对福州市大气颗粒物进行分析 ,对有代表性监测点的大气颗粒污染物进行形貌特征及成分分析比较 ,找出大气颗粒污染物的来源 ,从而为制定相应的防污染措施提供理论依据。样品取自市校园区和工业区的采样器 ,设在建筑物 3~ 4楼顶上 ,采样高度 9~ 12m之间 ,以空气自动泵抽出并定期采用纤维滤膜收集大气颗粒污染物 ,从中各剪下面积约为 5 0mm2 的…  相似文献   

6.
张继  郑晓华  寇云峰  宋仁国 《中国激光》2012,39(4):407002-144
采用脉冲激光沉积法(PLD)在单晶硅基底上制备了WSx固体润滑薄膜。利用X射线能谱仪(EDS)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)对薄膜的成分、形貌和微观结构进行了分析,采用球盘式磨损试验机在大气(相对湿度为50%~55%)环境下评价薄膜的摩擦学特性。结果表明:薄膜中S和W的原子数分数比(简称S/W比)在1.05~3.75之间可控,摩擦系数为0.1~0.2;S/W比高于2.0时薄膜成膜质量和摩擦系数显著恶化。正交试验法得出影响薄膜S/W比的因素主次顺序分别是气压、温度、靶基距和激光通量;最优工艺参数是温度150℃、靶基距45mm、激光通量5J/cm2、气压1Pa,可获得结构致密、成分接近化学计量比的WSx薄膜。  相似文献   

7.
我们利用透射X射线形貌技术观察了n—GaAs衬底及GaAs—Al_xGa_(1-x)As DH外延片中的晶体缺陷,采用高分辨率形貌技术与金相技术进行了分析,证实普通X射线形貌像中的衬度是由晶体缺陷形成的。根据获得的X射线形貌像,我们对n—GaAs衬底及GaAs—Al_xGa_(1-x)As DH外延片中缺陷水平作出了评价。采用常规的DH液相外延技术及质子轰击条形的器件工艺,将我们研究的衬底制成了激光器。测试结果表明:器件的成品率和质量与我们对衬底中缺陷水平的评价完全对应。  相似文献   

8.
针对激光熔覆再制造汽轮机转子轴颈,采用2 kW半导体激光器进行同轴送粉的激光熔覆Fe基合金试验,并在激光熔覆过程中对加工点附近的温度进行监控。利用扫描电镜(SEM)、X射线衍射仪(XRD)、X射线能量色散谱仪(EDS)研究了熔覆层的显微组织形貌、相结构与成分。结果表明,激光熔覆加热集中,检测部位的最高温度未超过70 ℃,整个修复过程平稳。Fe基合金熔覆层组织均匀、致密,与基体冶金结合,没有微观裂纹与气孔等缺陷。熔覆层组织主要为(Fe、Cr、C)合金与CrC两相。熔覆层的组织主要为典型的过饱和固溶体枝晶与枝晶间多元碳化物共晶组成,激光熔覆层与基体熔合过程中产生了元素互渗。  相似文献   

9.
研究了添加Mn、Mo、Ti合金元素对激光熔覆Fe Ni Cr+60%WC复合熔覆涂层微观组织和磁性能的影响。利用扫描电子显微镜(SEM),能谱仪(EDS),X射线衍射仪(XRD)对熔覆层进行微观组织、成分及物相分析。利用振动样品磁强计(VSM)对熔覆层的磁性能进行测试。研究结果表明激光熔覆WC-Fe Ni Cr复合涂层与基体具有良好冶金结合,表面无裂纹、气孔等缺陷。Mn、Mo、Ti合金元素的加入,使得复合涂层冶金反应及组织形貌更加复杂,Fe、Ni、Cr元素之间存在相互作用并与WC之间存在互熔扩散,并生成了新的无磁相Ti C,Mo C,Fe-Cr(σ相),Cr0.19Fe0.7Ni0.11,而且Mn、Mo、Ti合金元素的加入使复合涂层相对磁导率显著降低,复合涂层磁性能具有较强的稳定性。  相似文献   

10.
本文利用扫描电子显微镜(SEM)和X射线波长色散谱仪(WDS)、X射线能量色散谱仪(EDS)研究示波管屏黑表面形貌,并进行了微区成分分析。研究结果发现涂层发黑区有大量的碳沉积在荧光粉层表面,以至造成荧光屏发光不均匀的“黑暗”区。  相似文献   

11.
A review is given of the progress in electrophotographic science and technology in Western Europe during the years 1967 to early 1971. University research work is mainly directed towards two areas: 1) the electrical and physical properties of photoconductors, such as selenium, chalcogenides, oxides, and organic materials; and 2) the sensitization of these photoconductors. Industrial research teams report on the preparation of electrophotographic layers on development and on image evaluation. A bibliography including scientific papers and patents published on this subject during said period completes this review.  相似文献   

12.
13.
《现代电子技术》2015,(5):14-16
随着计算机技术、控制技术、通信技术及信息技术的飞速发展,人们对生活、办公环境安全性、舒适性的要求日渐增长,智能建筑应运而生。楼宇自动化控制系统是智能建筑的一个重要组成部分。通过结合具体的智能楼宇控制工程项目,在介绍系统概况的基础上,给出了系统的总体设计方案及子系统的监控方案,具有一定的实用价值。  相似文献   

14.
The authors describe the development trends and results of millimeter-wave systems in Japan in such fields as communication, radar, and measurement systems. The applications included are the W-40G waveguide transmission communication system, an automobile traffic control system using the 60-GHz band, a collision avoidance radar system for an automobile, a plasma electron density measuring system, and satellite communication. The authors describe the development of devices such as high-power FET amplifiers, traveling wave tube amplifiers (TWTAs), IMPATT amplifiers, low-noise amplifiers, and monolithic microwave integrated circuit (MMIC) devices used in constructing the millimeter-wave systems  相似文献   

15.
An experimental and theoretical study of the 1/f noise and the thermal noise in double-diffused MOS (DMOS) transistors in a BICMOS-technology has been carried out. By using an analytical model that consists of an enhancement MOS transistor in series with a depletion MOS transistor and a resistance, and by attributing noise sources to each device, the noise in DMOS devices is simulated accurately. Three distinct regions of operation are defined: enhancement transistor control, depletion transistor control and the linear region. In the first region, the noise is strictly determined by the enhancement transistor. It was found that the 1/f noise in this region is caused by mobility fluctuations and is very low. In the depletion transistor control region both transistors influence the total noise. Here the 1/f noise is dominated by the depletion transistor. The series resistance is only of importance in the linear region  相似文献   

16.
Zeroing in on ethical issues in nanotechnology   总被引:2,自引:0,他引:2  
Setting aside exaggerated notions of both the benefits and harms to be expected from nanotechnologies, we need to focus ethical investigation on specific initiatives at the nano scale that are already underway or planned. The aims are to anticipate ethical issues likely to arise in specific cases, to foster sensitivity to ethical issues and responsibility among nano specialists and policy makers, and to stimulate interchange between nano specialists and members of the public so that the public can become involved. After clarifying what the term "nanotechnology" embraces and looking at cautionary lessons from experience with the information technologies and biotechnology, the discussion turns to the importance of anticipating consequences, intended and unintended. Although specific nano options to consider are lacking, a brief survey indicates the issues to watch out for: preventable harms, conflicts about justice and fairness, respect for persons, and more specifically, safeguards for workers in new production processes, intellectual property concerns, preservation of university values in university/industry relationships, and conflicts of interest. Three main fronts of activity are needed to address ethical issues: 1) incorporating ethics research into nano research and development enterprises; 2) devising mechanisms to involve the public so that their perspectives and concerns feed back into research and development; and 3) initiating educational efforts at every level addressing both technical aspects and ethics and social implications aspects.  相似文献   

17.
This paper reviews recent progress in communication theory in Japan, mainly in the past three years. The topics to be discussed include 1) waveform transmission in band-limited channels and active transmission lines, 2) source-coding problems such as optimal quantizing characteristics, delta modulation, and linear transformation, 3) transmission codes, where mainly multilevel codes have been discussed, 4) new information transmission and modulation schemes, and 5) theories of traffic and switchingsystem design.  相似文献   

18.
A review of the basic research and industrial development of display devices in Western Europe during the years 1968 to early 1973 will be given. The display types considered are: 1) active displays such as cathode ray tubes, light-emitting diodes, electroluminescence cells, and gas discharge devices, and 2) passive displays such as laser displays, light valves, and ferroelectric and liquid-crystal devices.  相似文献   

19.
Systems are currently being designed for higher reliability and greater economy. Larger transmission capacity is required to meet a rapid increase in recent communication demands instigated by the introduction of video and information communications facilities. More flexibility, to deal with the variety of communication modes to come, and smaller hardware dimensions, to overcome situations caused by the high population density, seem to be particularly sought in the communication technology of Japan. Research and development concentrate on these objectives. The following is an explanation of the present state of the art and general trends in this country.  相似文献   

20.
Assessment of design implications due to degradation of CMOS devices is increasingly required in the latest technologies. This paper presents selected topics relevant to realize an efficient design-in reliability methodology in the latest generation CMOS technologies. NBTI is discussed in terms of characterization using On-The-Fly (OTF) methodology. Extension of OTF method is discussed using bias patterns to gain insights into NBTI under analog operation. A reliability simulation methodology is discussed against requirements for optimization and integration within an existing design flow. The features of this methodology are illustrated using some simple design examples.  相似文献   

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