A simple chamber for observing microscopic specimens in both top and side views

A method is described which permits the observation of microscopic specimens in both top and side views, a rapid change between the two views being possible without disturbing the specimen. The system requires the introduction of simple optical components into a culture chamber, does not restrict the types of microscopy that may be used, and does not necessitate modification of the microscope itself. The technique is discussed in relation to the study of tissue cells in culture, but may find applications in other areas.     

A preparation method for observing intracellular structures by scanning electron microscopy

In order to observe intracellular structures by scanning electron microscopy, excess cytoplasmic matrix must be removed from the fractured surface of cells. Previously we reported an Osmium-DMSO-Osmium method devised for this purpose. This method is very effective in revealing intracellular structures, but requires osmium tetroxide for initial fixation with some consequent disadvantages. In the present study, a revised Osmium-DMSO-Osmium method is reported, in which an aldehyde mixture is used as the initial fixative instead of osmium tetroxide. As fixation is carried out by perfusion in this revised method, better preservation of fine structures is achieved than by the original method, especially in the central nervous tissue which tends to suffer from post-mortem degeneration. Moreover this method can be applied to cytochemical studies of intracellular structures with a scanning electron microscope (SEM). In this study, acid phosphatase of lysosomes is demonstrated in a coloured SEM micrograph.     

A method for observing intracellular structures of free cells by scanning electron microscopy

A new method is described for scanning electron microscopic observation of cultured free cells using chitosan embedding. Intracellular structures of free cells can be clearly observed using a combination of the chitosan embedding and the Osmium–DMSO–Osmium (O–D–O) method. Chitosan, a polysaccharide, is not affected by the osmium maceration procedure central to the O–D–O method, which destroys other possible embedding media such as gelatin, agar, egg albumin and fibrin. Chitosan cracks to yield a fracture face which is featureless at low magnifications, and causes no recognizable artefacts.     

基于地标观测的导弹发射车定位定向算法

针对导弹发射车的特点,提出了一种高精度的定位定向算法。事先在发射场周围布设地标,用差分全球卫星定位系统测量出这些地标的位置;当发射导弹时,用发射车顶上的光电探测器测出其中3个地标的方位角和俯仰角;然后将参数分为垂直与水平两个通道交替估计,解算出发射车的位置和姿态。仿真结果表明,特别是在平原地形中不可避免的发射车与地标接近共面的情况下,与类似算法相比,本算法能够更加稳定地收敛到正确解。作为一个系统,外场实验证明本系统的位置精度为厘米级,方位精度为13角秒,横滚与俯仰精度均为25角秒。     

Improved method for the preparation of TiN-coated WC-Co-based samples for cross-sectional AEM investigation.

An improved method for the preparation of cross-sectional thin foils of coated WC-Co samples for studies by analytical electron microscopy is described. A braze alloy is used to join the sections of the sample together and the resulting sample is stable during subsequent grinding, dimpling, and milling operations. Cross-sectional micrographs provide examples of the efficacy of this method. No microstructural alteration associated with the brazing operation was observed.     

A simple phase-contrast scheme for observing transparent objects

A simple phase-contrast scheme, based on a photothermal cell, for observing transparent objects is described. A good visualization quality is shown for some objects, including those in a scattering medium.     

对激光扫描共聚焦显微镜观察血小板钙波动方法的改进

对激光扫描共聚焦显微镜观察血小板钙波动的方法进行了改进。解决了血小板贴壁不牢,加入的诱导剂混和不够充分等问题。大大提高了实验的成功率     

A method of observing the area of contact and the mechanical breakdown of a surface film

A new method of observing the contact area was applied to the investigation of the effect of surface roughness on the mechanical breakdown of a surface film. This method uses the difference in secondary electron emission yields from the carbon surface film and from the base metal. Contact spots between the gold surfaces are visible as bright spots on the secondary electron image.

The contact resistance decreases with increasing surface roughness in the region of low surface roughness. However, the greater the tangential displacement and contact load, the less the surface roughness effect becomes. The results of contact resistance are supported by analyses of the area of film removal.     

A simple technique for observing periodic nonlinearities in Michelson interferometers

We describe a simple, convenient method for measuring nonlinearities in displacement-measuring Michelson interferometers. Nonlinearities with a spatial periodicity of one optical fringe are a well-known source of error in precision interferometry. Our experimental technique for observing these errors is most immediately applicable to commercial interferometer systems for which the cube-corner retroreflectors can be attached directly to the faces of a beamsplitter cube, creating a monolithic interferometer optic with excellent noise immunity. The optical path difference in this bolted-together interferometer can be changed slightly by rotating the interferometer relative to an external laser. It should be noted that the basic principle described here—generating small path differences through a rotation of the optics relative to the laser—may itself be a source of significant errors in certain length measurements. The validity of our method has been demonstrated by measuring optical mixing errors of calculable magnitude. We describe a matrix method suitable for modeling optical mixing errors in both single-pass and double-pass (plane mirror) interferometers. Also, we report experimental measurements of periodic nonlinearities for two representative interferometers and conclude that, in the majority of engineering metrology applications, these errors are of only minor importance.     

A simple method for overcoming some problems when observing thick reflective biological samples with a confocal scanning laser microscope

A simple device is described, which allows the range of depth of scanning to be reduced when observing thick reflecting biological samples with a confocal scanning laser microscope (CSLM). Thick histological sections of human skin and rat brain stem were mounted between two coverslips (‘sandwich’ style) and the optical tomography was performed from both sides by turning the ‘sandwich’ upside-down. The samples were impregnated using standard Golgi–Cox, ‘rapid Golgi’ or other silver methods. The ability to turn the ‘sandwich’ upside-down is particularly useful when the reflective structure inspected is deep inside the section, i.e. near the lower surface of the specimen, or when it is opaque to the laser beam or excessively reflective.     

A new method of observing weak extended x-ray sources with the Reuven Ramaty high-energy solar spectroscopic imager

We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and gamma-ray telescope has much greater sensitivity than previous experiments in the 3-25 keV range, but is normally not well suited to detecting extended sources since their signal is not modulated by RHESSI's rotating grids. When the spacecraft is offpointed from the target source, however, the fan-beam modulation time-modulates the transmission by shadowing resulting from exploiting the finite thickness of the grids. In this article we detail how the technique is implemented and verify its consistency with sources with clear known signals that have occurred during RHESSI offpointing: microflares and the Crab Nebula. In both cases the results are consistent with previous and complementary measurements. Preliminary work indicates that this new technique allows RHESSI to observe the integrated hard x-ray spectrum of weak extended sources on the quiet Sun.     

Protein casting: A new replication technique for observing fluid surface structures

Certain insoluble copolymers form characteristic liquid crystalline structures at water/copolymer interfaces. The formation of these structures, discernable with phase contrast microscopy, correlates with biological activities as immunological adjuvants. In order to study such structures at the electron microscopic level, it was necessary to develop a preparation technique which preserved the water/polymer interface. A technique was devised, here called “protein casting,” which uses highly concentrated bovine serum albumin (BSA) in water, subsequently fixed with glutaraldehyde, to form a replica of the water/polymer interface. These casts appeared highly accurate at low magnifications, and resolved to less than 1ønm. This technique seems ideal for accurate replication of surfaces formed by nonmiscible liquids and should prove helpful in studies of other materials in aqueous suspension.     

Scanning tunneling microscopy of planar biomembranes

We combined planar membrane monolayer techniques with scanning tunneling microscopy (STM) to measure the thickness of metal-coated purple membrane (PM) isolated from Halobacterium halobium. Although the metal coating precluded obtaining high-resolution lateral information, it facilitated obtaining high-resolution vertical information. For example, the apparent mean thickness of planar PM and variations in thickness of enzyme-treated PM could be detected and quantified at sub-nanometer resolution.     

A procedure to prepare cross-sectional samples for TEM

Cross-sectional transmission electron microscopy (XTEM) is an imaging technique particularly suited to the study of layered structures. For integrated electronic devices it has become a common practice to use XTEM to assess the shape and crystallinity of component layers as well as defect structures introduced by processing. A procedure for preparing samples to be viewed by XTEM is described.     

天气现象自动化观测仪器评估方法

根据气象业务需求,结合天气现象人工观测现状和天气现象自动化观测仪器的技术发展现状,通过前期天气现象组网观测试验数据分析,以《天气现象仪功能规格需求书》为依据,总结了针对降水现象、地面凝结现象以及视程障碍现象的评估方法,主要对仪器的采集性能和识别性能进行评估和分析,并根据功能规格需求书提出指标要求,为天气现象自动观测考核试验以及业务化应用提供依据。     

A rapid method for estimating volume ratios.

A rapid stereological method is proposed for estimating the volume ratio V(K2)/V(K1) of two bodies K1, K2 such that K2 is embedded in K1. If K1, K2 fit approximately into a 'star specimen' model, then a single section, taken at a certain level through K1, provides a rather accurate estimate of V(K2,/V(K1). For a population of moderately similar star specimens, a constant sectioning level can be estimated from a sample using a least squares criterion. A pilot experiment involving mouse lymph nodes, aimed at estimating the mean and the variance of the individual fractions V (paracortex)/V(node), indicates a fair robustness against deviations from the model.     

形体分析法在组合体视图中的应用研究

组合体是工程制图中具有特殊性和重要地位的立体。形体分析法在组合体视图中发挥了重要作用,应用此方法可将复杂的立体分解成基本几何体和简单体,使工程立体化繁为简、化难为易。笔者研究了组合体的概念、投影规律、形体分析法及其在组合体绘图、尺寸标注、读图中的应用。     

Contrast enhancement of negatively stained macromolecules and biomembranes by single sideband phase contrast interference.

A straightforward procedure is described for the production of contrast enhancement of negatively stained macromolecules and biological membranes by single sideband phase contrast interference (electron optical shadowing). The instrumental adjustment required to produce this type of phase contrast illumination is readily achieved by beam deflection from the strioscopic (dark field) mode. Part of the hollow cone of electrons from the annular condenser aperture that are unscattered by the specimen are permitted to pass through the objective aperture and interfere with the scattered beam. The electron optical shadowing effect is produced because only one side of the unscattered beam is used. Careful adjustment of the beam tilt control, with the ability to tilt in any azimuth, allows optimal illumination conditions to be achieved. The results presented show the increased image contrast obtained using as specimens the purified cylindrical macromolecule from human erythrocyte membranes, purified nuclear envelopes and collagen fibres.     

A method for testing lubricants under conditions of scuffing. Part I. Presentation of the method

A method for the tribological assessment of lubricants under conditions of scuffing is presented. The method uses a four‐ball tester, and allows one to assess the effect of lubricant on scuffing intensity through an analysis of changes in the friction torque and wear of the stationary balls, at continuously increasing load. The behaviour of a lubricant under scuffing conditions can be characterised using the so‐called limiting pressure of seizure p_oz, which depends on the load at which the balls seize and the average value of the wear area calculated from the wear‐scar diameters measured on the stationary balls. A comparison is made ‐ from the point of view of the resolution, time consumption, and cost ‐ of the new method with the existing, standard tests, using a four‐ball tester and a gear test rig (FZG). It is concluded that the proposed method, unlike standard FZG and certain four‐ball tests, enables one to differentiate between gear oils, in agreement with their API GL performance level. The very short run‐time of the new method enables one to perform more tests and obtain a low standard deviation. The new method is much cheaper than the standard four‐ball and FZG methods.