基于面阵CCD的光电测量设备光学系统像面照度不均匀度测量系统

一直以来光电测量设备光学系统像面照度不均匀度检测都没有精确的测量设备和检测系统.介绍了光电测量设备光学系统像面照度不均匀度测量系统.该测量系统采用积分球作为均匀面光源,面阵CCD作为光电接受器.通过对CCD进行均匀性校正的方法实现了对光学系统像面照度不均匀度的定量评价,检测结果准确、可靠.     

定向干扰激光的红外成像建模与仿真

为有效应对红外成像制导武器,激光定向干扰技术在近年得到重点发展,并有望成为未来红外对抗的主要方式。着眼于对激光干扰条件下红外系统成像特性的研究需求,对机载激光定向干扰从发射、大气传输、光学系统传输以及探测器响应的全链路过程进行了分析建模,构建了激光干扰条件下红外系统成像特性的仿真模型,最后通过试验验证了文中方法和模型在对激光的红外成像灰度等级、成像光斑及灰度分布特性、成像饱和与致盲毁伤效果方面能够有效反映红外成像系统对激光的实际响应特性,并取得与实测试验相近的仿真结果,从而为后续深入研究激光定向干扰效能奠定基础。     

虚拟现实技术在电子显微镜操作模拟中的应用

基于虚拟现实技术对电子显微镜外观结构及其操作流程进行虚拟动态仿真。首先运用三维建模软件对电子显微镜进行精细建模,并对其中涉及到的关键问题,如模型优化、材质制作等进行了阐述。在此基础上,研究运用虚拟现实引擎对电子显微镜的操作流程模拟进行了设计与实现。采用这种的模拟系统,用户可以在虚拟环境下直观、交互地了解电子显微镜的复杂结构,并体验电子显微镜的操作流程。该项工作对电子显微镜的三维动态展示、使用流程演示、用户体验式培训都具有很好的应用意义。文章给出了实例和可视化结果。     

几种热带水果花粉的环境扫描电镜观察

环境扫描电镜可以对很多含水的、导电性差的生物样品进行直接观察，从而避免用常规扫描电镜观察时，由于生物样品经脱水、临界点干燥和导电处理而可能引起的人为变化。本文利用环境扫描电镜，对几种热带水果荔枝、龙眼、芒果、木瓜、杨桃的花粉及其相应的器官进行了直接观察，获得了较满意的结果。     

电子显微镜的现状与展望

本文扼要介绍了电子显微镜的现状与展望，透射电子显微镜方面主要有：高分辨电子显微学及原子像的观察，像差校正电子显微镜，原子尺度电子全息学，表面的高分辨电子显微正面成像，超高压电子显微镜，中等电压电镜，１２０ｋＶ，１００ｋＶ分析电镜，场发射枪扫描透射电镜及能量选择电镜等，透射电镜将又一次面临新的重大突破，扫描电子显微镜方面主要有：分析扫描电镜和Ｘ射线能谱仪，Ｘ射线波谱仪和电子探针仪，场发射枪扫描电镜和     

Electron microscopy characterization of airborne micro- and nanoparticulate matter

The aim of this work was to offer a state-of-the-art critical survey for characterizing airborne nano- and microparticles by means of electron microscopy (EM) techniques and to highlight advantages and limits of different possible operation modes. Procedures of collection and sample preparation are revisited and improved to analyse airborne particles deposited on filtering membranes by using various sampling methods. Three kinds of electron microscopes are used to this end: scanning electron microscope (SEM), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Following and extending previous studies, we optimized procedures by varying both the sample collection/preparation and the operational parameters of the microscopes. In particular, we diversified the sampling methods applied, using ad hoc filters as well as common filters for standard gravimetric measures. This approach enabled us to achieve a simple and clean procedure allowing direct SEM or TEM observation of the collected particulate matter.     

细胞核凋亡过程中核基质的变化

在非细胞体系中以细胞色素C作为诱导剂，诱导小鼠有细胞核发生凋亡，在透射电子显微镜及扫描电子显微镜下观察到凋亡的一现典型的凋亡形态学特征，整装电镜的结果显示，在凋亡过程中核基质结构被破坏，但核基质结构仍然存在，并最终形成凋亡小体的结构基础。     

盾叶薯蓣类原球茎的细胞结构及薯蓣皂苷的组织化学定位

为揭示盾叶薯蓣类原球茎发育的细胞学基础和薯蓣皂苷在各离体培养繁殖体中的分布,应用石蜡切片技术、扫描电镜和透射电镜制片技术及组织化学方法进行了研究。制片观察结果显示：盾叶薯蓣类原球茎是由多层鳞片叶包裹的致密小球体,从外至内由周皮、基本组织和分散在基本组织中的维管束组成,初生增厚分生组织和原形成层是其增大的主要原因之一;组织化学结果显示：愈伤组织和类原球茎中均有薯蓣皂苷的分布,而表皮栓质化的愈伤组织和生根类原球茎中薯蓣皂苷的含量相对较多。     

Development of a 1 MV field-emission transmission electron microscope

We developed a 1 MV field-emission transmission electron microscope. This paper reports details and specifications of the instrument. The microscope was designed to obtain a bright and coherent electron beam by using the field emission gun equipped with a pre-accelerating magnetic lens and the high-voltage power supply with high stability (0.5 ppm min(-1)). Using this microscope, the brightness of 1.8 x 10(10) A cm(-2) sr(-1) and the lattice resolution of 49.8 pm were attained.     

离子束沉积PdC_x纳米结构及其输运性能

采用离子束沉积方法制备了PdCx纳米结构,并对材料的电子输运性能进行了研究。利用扫描电子显微镜(SEM)和X射线能谱仪(EDX)分析了材料的微观结构和组成,利用原子力显微镜(AFM)分析了纳米结构的尺寸大小,利用高分辨率透射电子显微镜(HRTEM)分析了材料的原子结构。采用电阻桥测试了PdCx纳米结构的电阻,在低温保持器(OXFORD2)中对其电子传输性能进行了测试。X射线能谱仪(EDX)检测结果表明,该纳米结构金属含量低,表现出非金属性。高分辨率透射电子显微镜(HRTEM)检测结果表明,其为PdCx多晶纳米结构,与所观测到的电子输运性能结果一致。     

草甘膦对大豆超微结构及光合指标影响的研究

利用透射电镜和扫描电镜,研究转基因抗草甘膦大豆和非抗草甘膦大豆东农42喷施草甘膦后大豆光合器官叶片的超微结构变化,并结合叶绿素含量、光合速率的测定,对比分析了抗草甘膦大豆和东农42在结构及生理功能上对草甘膦的表现及结构与功能变化的关系.研究结果表明抗草甘膦大豆对草甘膦的胁迫可以看作是一种适应.它首先经过一个损伤期,然后进入修复期,最终到基本恢复,表现出对草甘膦的抗性.而东农42的光合系统及光合功能则被草甘膦所彻底破坏.本文对其原因进行探究,以期为转基因作物育种尤其是超微结构方面的研究及草甘膦作用机理的研究有一定帮助.     

姬松茸新菌株J3的细胞生物学鉴定与菌盖不同部位微量元素含量分析

利用扫描电镜和X射线能谱仪对姬松茸菌株J3与原菌株J1子实体的菌盖皮、菌盖内和菌褶中常见的微量元素S、P、Ca、K、Fe、Cu和Zn进行了测定,计算了它们的相对重量百分比。利用扫描及透射电境观察姬松茸菌株J3与原菌株J1菌丝体、子实体的表面和内部结构。结果表明菌盖皮、菌盖内和菌褶均含上述各种微量元素,但含量各不相同;姬松茸J3菌丝表面有明显竹节状,在菌丝的外部形态特征上不同于原菌株J1。此外,姬松茸J3细胞壁厚,而出现重度质壁分离;姬松茸菌株J3子实体中淀粉粒、线粒体均比原菌株J1多。由此,说明姬松茸J3与原菌株J1在细胞学特性存在一定差异。     

电荷耦合器件的像质评价技术

运用图像积分抽样理论，并利用刀口响应方法对电荷耦合器件的像质进行了完整评价，用真频传递能力。混淆效应，信息密度等示性参数准确表述了电荷耦合器件的成像特性。     

用侧向外延生长法降低立方相GaN中的层错密度

尝试用侧向外延(ELOG)方法来降低立方相GaN中的层错密度.侧向外延是在SiO2/GaN/GaAs图形衬底上进行的,对生长所得的立方相GaN外延层用扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行了观察和分析,TEM的平面像表明经过ELOG方法生长后,立方相GaN外延层中的层错密度由侧向外延生长前的5×109cm-2降低至生长后的6×108cm-2.双晶X射线衍射(DCXRD)测量给出侧向外延前后外延层ω扫描(002)衍射摇摆曲线的半高宽(FWHM)分别为33′和17.8′,表明晶体质量有了较大改善.对立方相GaN侧向外延过程中层错减少的机制进行了讨论.     

Plan-view imaging of oxygen-induced reconstruction on Ag(110) surface. II. Effect of high-energy electron thinning

The feasibility and the limitation of the 'high-energy electron thinning' method for the production of surface-science-grade samples in situ in the electron microscope are studied. Exploiting the electron beam supplied by high-voltage electron gun in electron microscope, this method can be readily realized. An obvious advantage of this method is that we can monitor the sample surface concurrently. However, this sample preparation method depends strongly on the sample material and the local environment within the electron microscope. Factors relating to the electron thinning speed are briefly discussed.     

Electron microscopy at a sub-50 pm resolution

An aberration-corrected electron microscope developed in CREST project has been applied for imaging atoms and clusters buried inside crystals. The resolution of the microscope in scanning transmission electron microscopy (STEM) has experimentally proved to be better than 47 pm by use of a cold-field emission gun at 300 kV. The high resolution has given an advantage for imaging light elements such as lithium atoms discriminating one by one. Moreover, a three-dimensional structure imaging has been demonstrated for dopant clusters by a sub-50 pm STEM, using its high depth resolution.     

A study of atypical grain growth properties for SnO2 thin films

SnO₂ thin films were grown on Si substrate using the chemical vapor deposition(CVD) method. The surface of the thin film was examined using a transmission electron microscope (TEM) and a scanning electron microscope (SEM). Atypical shaped grains and atypical columnar structures were observed on the SnO₂ thin films that were exposed to air after first deposition and during re-deposition in anaerobic conditions in the CVD. The electrical properties of SnO₂ thin films feature a lower range of resistance in single mode, but after the atypical particles appear, the electrical resistance decreased.     

In situ TEM/SEM electronic/mechanical characterization of nano material with MEMS chip

Our investigation of in situ observations on electronic and mechanical properties of nano materials using a scanning electron microscope （SEM） and a transmission electron microscope （TEM） with the help of tradi- tional micro-electro-mechanical system （MEMS） technology has been reviewed. Thanks to the stability, continuity and controllability of the loading force from the electrostatic actuator and the sensitivity of the sensor beam, a MEMS tensile testing chip for accurate tensile testing in the nano scale is obtained. Based on the MEMS chips, the scale effect of Young＇s modulus in silicon has been studied and confirmed directly in a tensile experiment using a transmission electron microscope. Employing the nanomanipulation technology and FIB technology, Cu and SiC nanowires have been integrated into the tensile testing device and their mechanical, electronic properties under different stress have been achieved, simultaneously. All these will aid in better understanding the nano effects and contribute to the designation and application in nano devices.     

Fabrication and Electrical and Mechanical Properties of Carbon Nanotube Interconnections

Individual carbon nanotubes (CNTs) have been cut, manipulated, and soldered via electron‐beam‐induced deposition of amorphous carbon (a‐C) and using a scanning tunneling microscope inside a transmission electron microscope. All CNT structures, including simple tube–tube connections, crossed junctions, T‐junctions, zigzag structures, and even nanotube networks, have been successfully constructed with a high degree of control, and their electrical and mechanical properties have been measured in situ inside the transmission electron microscope. It is found that multiple CNTs may be readily soldered together with moderate junction resistance and excellent mechanical resilience and strength, and the junction resistance may be further reduced by current‐induced graphitization of the deposited a‐C on the junction.     

Scanning electron mirror microscopy and scanning electron microscopy of integrated circuits

The recently developed scanning electron mirror microscope (SEMM) is compared with other types of electron microscopes, such as the electron mirror microscope (EMM) and the scanning electron microscope (SEM), for examining integrated circuits. Potential advantages of the SEMM include high resolution, elimination of electron bombardment damage, and high sensitivity of voltage gradients, magnetic fields, and topography. Preliminary observations of integrated, circuits obtained with the feasibility SEMM at various specimen potentials are discussed.