共查询到20条相似文献，搜索用时 171 毫秒
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作为研究物质微观结构的有力工具,扫描隧道显微镜（Scanning Tunneling Microscopy）与其它种类的显微镜相比,它的分辨本领却可以达到10—10米．以量子力学为基础的扫描隧道显微镜,可以在大气、液体、真空状态下工作,可以在4．2K到1000K之间的温度下工作;并且对样品也无特殊要求,可以测量单晶、多晶、非晶等样品表面;特别是扫描隧道显微镜可以与其他实验设备结合,应用更加有效、灵活．因此,扫描隧道显微镜在物理学、化学、生物学、纳米材料等领域中都得到了深入而广泛的应用,并取得了一系列重要的研究成果． 相似文献
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细胞生物学的建立和发展都离不开显微技术,本文对几种主要光学显微镜、电子显微镜以及扫描隧道显微镜和原子力显微镜的工作原理及其在细胞生物学中的应用作简要阐述。 相似文献
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探针对扫描隧道显微镜成像起至关重要的作用。本文分别对电化学腐蚀法自制的钨丝探针和剪切法制得的铂铱探针进行扫描光栅图像比较分析。结果表明,相比铂铱探针,钨丝探针虽然制备繁琐,反应条件不易控制,但是尖锐轴对称形的钨丝探针扫描样品形貌更加细微,用作扫描隧道显微镜探针时扫描成像质量高。该研究为扫描隧道显微镜探针的选用提供了依据。 相似文献
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扫描隧道显微镜(MicroNanoAFM -III型原子力显微镜),简称原子力显微镜,它集STM、AFM接触/非接触/侧向力/轻敲模式于一体,使人们能够通过实验论证,清晰地观察到物质表面的原子排列状态。在实验教学中,让学生通过实际操作,观察和验证量子力学中的隧道效应,真正深入到原子世界,了解原子结构排列的真实图像,对培养学生科研兴趣和创造性思维,使学生对纳米尺度的进一步了解和深入研究具有极其重要的作用。 相似文献
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本文简述了在量子力学的发展过程中所带动的激光、半导体、扫描隧道显微镜、量子信息等技术的形成及影响，并借此强调了基础理论对于技术发明的重要性。 相似文献
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论述了在常温下和在大气状态下,扫描隧道显微镜（STM）在石墨薄膜表面上的电场加工实验,并对作用机理进行了分析,认为表面结构现象生成是场蒸发效应作用的结果,其导电性受外电场力的大小和薄膜层数之间的束缚力的影响。 相似文献
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娄金亮 《石家庄铁路职业技术学院学报》2021,(1):73-77
结合张吉怀高速铁路项目工程,阐述了三维全断面自动扫描技术在隧道施工中的应用。该技术能够有效地控制隧道超、欠挖,隧道初支、二衬混凝土方量,确保隧道开挖、初支及二衬断面均满足设计要求。该技术为今后类似工程施工提供一些可借鉴的经验。 相似文献
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在科学前沿的纳米科学与技术研究领域中,扫描隧道显微镜是关键的设备,相当于纳米科学研究中的眼睛和手。扫描隧道显微镜的发明是纳米科技中的一个里程碑式的进步,使得人类实现了对单个原子、分子的观察和操纵。 相似文献
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Marja Laasonen Veijo Virsu Suvi Oinonen Mirja Sandbacka Anita Salakari Elisabet Service 《Reading and writing》2012,25(9):2247-2273
We investigated whether poor short-term memory (STM) in developmental dyslexia affects the processing of sensory stimulus sequences in addition to phonological material. STM for brief binary non-verbal stimuli (light flashes, tone bursts, finger touches, and their crossmodal combinations) was studied in 20 Finnish adults with dyslexia and 24 healthy controls. To determine sensory Item STM, participants were asked to match pairs of sequences of increasing length. In Time STM, participants matched pairs of five-stimulus-sequences of increasing stimulus onset asynchrony between the stimuli. Phonological STM was studied with digit span forwards and backwards, pseudoword span, pseudoword matching span, and pseudoword repetition. Earlier results associating phonological STM impairment with dyslexia were replicated. Dyslexic participants also performed more poorly than controls in sensory STM, suggesting that they have general difficulties in representing temporal sequences in STM. Further, sensory STM, phonological STM, temporal acuity, and reading ability were correlated, pointing to shared processes. 相似文献
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介绍扫描探针显微镜教学演示软件。该软件将CAI技术和SPM技术结合在一起，主要运用文字说明，静态图像，三维动画，模拟仿真等方法，对SPM的初学者进行了SPM的原理介绍和使用培训，可以大大缩短他们的学习时间，并能使其在较短的时间内对SPM有个较为深入和全面的了解。 相似文献
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The influence of external low frequency (0-100 Hz) vibration on the tip-sample interaction in SPM is the main concern of this paper. A concept, vibration rejection ratio (VRR) proposed by Thompson et al, was investigated theoretically and experimentally. A concise theoretical background was introduced, a vibration stimulating and measuring system for SPM was built up, and an experimental research of the influence on SPM VRR was carried out with different SPM probes, samples, tip pre-loads and open/close loops of tip-sample interaction. It was proved both in theory and experiment that SPM VRR had correlations with the spring constant, the air damping constant, the effective mass of the cantilever, the contact spring constant and the contact damping constant between tip and sample. SPM's vibration rejecting ability can be improved by longer cantilever probe, softer sample surface, greater tip pre-load, and close-loop control for tip-sample interaction. More attention should be paid to a proper combination of the above parameters. 相似文献
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本文讨论了调制信噪比是如何影响正弦位相调制(SPM)干涉仪精度的。为了改善调制信噪比,本文提出一种新的SPM干涉仪,其中参考波和检测波由—加了正弦电压的LiNbO_3电光晶体所调制,这种方法的调制信噪比较振镜调制法高,因此能用电光调制器提高SPM干涉仪的测量精度。 相似文献
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This study longitudinally investigated the relationships between verbaland visual short-term memory (STM) and the acquisition of decoding from thepre-reading through the early acquisition stages in 63 Hebrew-speakingchildren Test waves occurred in kindergarten, first grade and second grade.IQ, visual and verbal STM and decoding ability were assessed. The dataindicated that while both verbal and visual STM in kindergarten were significantlycorrelated to later decoding skill, pre-reading visual STM was a stronger predictor.The results further showed that pre-reading performance on the WISC-R BlockDesign test predicted later decoding ability, while performance on theWISC-R Vocabulary test did not. Lastly decoding skill in grade 1 was foundto predict only visual in grade 2. These results indicate that visualparameters may make a crucial contribution to the acquisition of decodingskills. The size of pre-reading visual STM capacity appears to play a rolein this process. The relationship between visual STM and decoding may bebidirectional, as learning to decode appears to develop visual STM. It issuggested that either language-related or task-related factors may accountfor these counter-to-mainstream results. 相似文献
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西江流域有机氯农药含量组成特征及年通量 总被引：1，自引：0，他引：1
刘艳霖 《深圳信息职业技术学院学报》2008,6(4):76-80
用固相萃取和气相色谱法对西江（珠江的主干）进行了为期1a的水相和颗粒相中17种有机氯农药（OCPs）测定。结果表明,水相OCPs的含量范围在2．28～10．21ng／L之间,颗粒物是OCPs的含量变化在20．29-58．74ng／g之间,经过分析得出西江水体中,有机氯农药主要以水相为主,颗粒物中农药所占比例远小于水相中。就OCPs来讲,研究区水质符合国家I类水标准。其来源方面地表径流对此有很大的贡献。西江中六六六类、DDT类和总OCPs的年通量为272．3,164．6,1245．3kg。 相似文献
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色散和自相位效应是制约1550 nm有线电视(CATV)系统无中继传输距离的主要因素。针对传统补偿方法在模拟CATV系统应用上的缺点,提出了双波长波出复用(WDM)技术,通过合理的频道划分,实现对色散和自相位的有效补偿。 相似文献
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This study determined the degree to which the phonological and executive components of memory reflect language-specific capacities in Spanish and English vocabulary. We tested whether the memory processes in a sample of English language learners found in Grade 1 also emerged in Grade 2. For the total sample (N = 90), Grade 1 English STM measures shared a common construct with Spanish STM, whereas Grade 2 STM measures were language dependent. In contrast, WM measures were language independent across grades 1 and 2. When vocabulary subgroups were analyzed, a subgroup × type of memory task emerged. The results showed that performance on Spanish and English STM tasks were a function of high and low Spanish and English vocabulary knowledge, whereas WM was not. The relationship between language-specific processes in memory was discussed. 相似文献
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李济生 《中国现代教育装备》2014,(9):39-41
针对单片机原理课程内容陈旧的问题,提出了以新型单片机STM32代替MCS51。通过课程内容改革,引进新型的STM32实验平台,采用理论与实践合一的教学模式,加大对学生的综合训练力度,显著提升了课程教学水平。 相似文献