LDA侧泵Nd玻璃的高光束质量激光放大器研制

研制了一台高光束质量、高稳定的基于激光二极管阵列(LDA)侧泵Nd玻璃的纳秒方形激光脉冲放大器。为了获得较高的输出能量,采用LDA泵浦的"串联式双程放大"高增益组件进行能量放大。同时,为了获得高光束质量的光斑,利用液晶空间光调制器(LCSLM)对光束近场分布进行空间整形,以便得到超高斯平顶分布的光束,并对后级放大器增益不均性进行预补偿,最终得到了光束口径为Φ13mm、光束近场调制度小于1.22∶1的激光输出。放大器工作波长为1 053nm,当注入500nJ的3ns方形激光脉冲时,得到无脉冲畸变激光脉冲能量为100mJ、能量不稳定度为2.14%(均方根)和远场角漂移小于11μrad的高光束质量激光输出。     

激光扫描共聚焦显微镜在石油地质学中应用改进

激光扫描共聚焦显微镜(CSLM)被应用于石油地质学各方面的研究目前仍处于探索之中,为了更有效开发该仪器的功能应用于石油地质学领域,本文以东海盆地西湖凹陷秋月一井致密砂岩储层岩石薄片为例,应用CSLM观察和计算了孔喉直径、结构、形态和油气赋存状况,同时改进了孔隙度计算方法,提高了精度;以塔里木盆地顺904井志留系储层流体包裹体薄片为例,改进了测量油包裹体的气液比的方法,减少了油包裹体的荧光遮盖效应,提高了精度,并结合热动力模拟软件恢复了古压力值.     

In vivo determination of fibril orientation in plant cell walls with polarization CSLM

Congo Red fluorescence is used to detect cellulose in the wall of plant cells. The orientation of the cellulose fibrils is determined by using polarized light for excitation. The absorption characteristics of Congo Red make this approach a method of choice for applications with any standard confocal scanning laser microscope (CSLM). The semiquantitative character of CSLM observations combined with the non-toxicity of the stain allow a very fast and reliable assessment of cellulose orientation in the wall of living plant cells.     

Interactions between sodium caseinate and LBG in acidified systems: Rheology and phase behavior

The behavior of model systems formed by different concentration of sodium caseinate and locust bean gum (LBG) was investigated using confocal microscopy (CSLM) and rheological measurements in order to determine the interaction between these two ingredients in acidified dairy products. A visual phase diagram was constructed at different biopolymer concentrations and four different types of systems were observed for the mixtures in the isoelectric point of protein: one-phase gels (G1P), two-phase gels (G2P), one-phase liquid mixtures (L1P) and two-phase liquid mixtures (L2P). These different systems resulted from the different kinetics of phase separation and gel formation. The one-phase systems (gels and liquid mixtures) showed a micro-phase separation when visualized by CSLM, although they were homogeneous at macroscopic level. In a general way, the micro or macro phase separation led to a biopolymer concentration on separated phases, resulting in an increase of the stress at fracture for the gels or the viscosity for the liquid mixtures. However, the behavior of the whole system did not correspond to the sum of the mechanical properties of separated phases.     

研究蛋白质凝聚凝胶的技术进展

由于蛋白质形成的凝胶会影响食品的质构和品质,所以研究蛋白质凝胶对于食品科学有极其重要的意义.然而,蛋白质形成凝胶的机理过于复杂,需要更先进的技术来研究.介绍了用于蛋白质凝胶研究的最新技术进展,如原子力显微镜(AFM),共聚焦激光显微镜(CSLM)和漫射波光谱(DWS).与传统研究凝胶的方法如动态流变仪和扫描电子显微镜(SEM)相比,这些新方法简化了样品的预处理,有实现在线测定的可能.由于样品处于天然状态,所以反映的信息更具有真实性,加上高分辨率,可以实现蛋白形成凝胶过程分子水平的可视化.因此,采用以上的新技术可以为研究蛋白凝胶的形成提供更多的信息.     

Measurements of fibre direction in reinforced polymer composites

High-quality data on the three-dimensional (3-D) spatial distributions of glass and carbon fibres in fibre-reinforced polymer composites are important for both process control and the modelling of the mechanical and thermal properties of these composites. The advent of economical, high-speed, image analyser systems has enabled numerous research groups to measure directional distributions of fibre samples. Specimens are microtomed and polished and, using optical reflection microscopy, thousands of elliptical fibre images may be analysed within a short period of time. From the eccentricity of the fibre images, estimation of the angles (θ, φ) of each fibre relative to the vertical axis and within the measurement plane is deduced. However, this measurement is subject to considerable error. The confocal scanning laser microscope (CSLM), operating in fluorescence mode or reflection mode, is capable of improving the angular resolution (δθ, δφ) for all fibre directions. The ability of the CSLM to optically section glass and carbon fibre-reinforced polymer composites down to depths of 20 or 30 μm allows the user to determine accurate fibre directions from the apparent movement of fibre profiles. The CSLM has the potential for standardizing measurements of 3-D fibre directions in polymer composites and providing the quality directional data which are required for the theoretical modelling of composite processing and composite strength.     

Contrast enhancement and depth perception in three-dimensional representations of differential interference contrast and confocal scanning laser microscope images

A commonly used three-dimensional reconstruction method in confocal scanning laser microscopy (CSLM) involves the generation of stereo views by stacking optical sections. Under certain conditions the resulting stereo pairs exhibit inferior quality with respect to contrast and depth perception. A method based on digital image processing is described in which the individual images are enhanced prior to reconstruction, thereby increasing the number of usable optical sections by a factor of up to five. Furthermore, we introduce a new contrast enhancement transformation based upon local statistics and a grey-level probability density function that provides improved depth perception. Digital image processing methods map a discrete grey scale onto a continuous, unbounded interval. Inasmuch as a closed, discrete grey scale is required for computer display purposes, we present an appropriate mapping function derived from an entropy criterion.     

��иּ�������Ϊ��ԭλ�۲�

The behaviors of inclusions in liquid bearing steel were in- situ observed with confocal laser scanning microscopy (CLSM). Samples from 4heats were reheated to steel making temperature, and after a period of holding the samples were rapidly cooled. Then the samples were observed under SEM with EDS to analyze inclusions. The results show that inclusions in original bearing steel samples are mostly MgO??Al2O3 with out- layer of CaS, while inclusions in liquid bearing steel after CLSM treatment are xAl2O3??yCaO. The inclusions with high liquid ratio spread on the interface between liquid steel and argon gas, as well as there are collision and combination of xAl2O3??yCaO and MgO??Al2O3. It can be concluded that the main formation cause of Ds inclusions is collision and combination between xAl2O3??yCaO inclusions with high liquid ratio or between these inclusions and MgO??Al2O3 inclusions. Reducing Ca content in liquid steel to decrease CaO content in inclusions and the liquidation of inclusions can decrease the formation of Ds inclusions.     

Three-dimensional imaging in fluorescence by confocal scanning microscopy

The improved resolution and sectioning capability of a confocal microscope make it an ideal instrument for extracting three-dimensional information especially from extended biological specimens. The imaging properties, also with finite detection pinholes are considered and a number of biological applications demonstrated.