Improvement of the axial trapping effect using azimuthally polarised trapping beam

A dual optical tweezers system,which consists of a doughnut mode optical tweezer (DMOT) with the azimuthally polarised trapping beam and a solid mode optical tweezer (SMOT) with the Gauss trapping beam was constructed to compare the axial trapping effect of DMOT and SMOT.The long-distance axial trapping of ST68 microbubbles (MBs) achieved by DMOT was more stable than that of SMOT.Moreover the axial trapping force measured using the viscous drag method,was depended on the diameter of the particle,the laser power,and the numerical aperture (NA) of the objective lens.The measurement of the axial trapping force and the acquisition of CCD images of trapping effect confirmed that the DMOT showed excellent axial trapping ability than SMOT.A simple and effective method is developed to improve axial trapping effect using the azimuthally polarized beam as trapping beam.This is helpful for the long-distance manipulating of particles especially polarised biological objects in axial direction.     

Finite element computations for unsteady fluid and elastic membrane interaction problems

The interaction between the hydrodynamic forces of a flow field and the elastic forces of adjacent deformable boundaries is described by elastohydrodynamics, a coupled fluid–elastic membrane problem. Direct numerical solution of the unsteady, highly non-linear equations requires that the dynamic evolution of both the flow field and the domain shape be determined as part of the solution, since neither is known a priori. This paper describes a numerical algorithm based on the deformable spatial domain space–time (DSD/ST) finite element method for the unsteady motion of an incompressible, viscous fluid with elastic membrane interaction. The unsteady Navier–Stoke and elastic membrane equations are solved separately using an iterative procedure by the GMRES technique with an incomplete lower-upper (ILU) decomposition at every time instant. One-dimensional, two-dimensional and deformable domain model problems are used to demonstrate the capabilities and accuracy of the present algorithm. Both steady state and transient problems are studied. © 1997 John Wiley & Sons, Ltd.     

嵌入式实时操作系统μC／OS—Ⅱ串口通信的设计与实现

为解决实时操作系统μC／OS-Ⅱ串口通信设计中信号量、消息邮箱使用方法的问题．提出了一种以STM32V评估板为硬件平台和μC／OS-Ⅱ的串口通信程序设计方案。该方案采用Cortex—M3架构的ARM处理器STM32F103VB作为主控制芯片,ST3232作为串口通信电平转换器。软件设计部分描述了信号量、消息邮箱的应用场合和基本操作方法,通过信号量和消息邮箱的配合使用保证任务间的数据传输的同步性。给出了整个程序中的设计思路,程序开发使用STM32F103VB处理器自带的固件库,减少了繁琐的寄存器配置,降低了程序开发强度。实验验证了在2种不用通信速率下数据传输具有误码率低、传输稳定可靠的特点．并且若能够配合相应的数据校验算法就可将其应用于工业现场的数据通信。     

中文图形12864点阵液晶显示模块与51单片机的并行接口电路及C51程序设计

讨论如何利用软件控制LM3033B-0BR3液晶显示模块时序,采用C51语言编程,驱动液晶模块实现并行传输方式的字符、汉字以及图形显示。具体阐述了LM3033B-0BR3液晶显示模块与单片机AT89S52的并行接口电路和软件编程方法。     

拓扑分子格的ST*分离性公理

由半开元、半拓扑概念出发在拓扑分子格中引入 ST* 分离性公理 ,给出它们的刻画 ,推广文 [2 ]中 T* 分离性公理 ,并得到 ST* 分离性与 T* 分离性之间的关系。     

基于Corvis ST医学影像的角膜轮廓提取算法

目前已有的轮廓提取算法在提取可视化角膜生物力学分析仪(corneal visualization scheimpflug technology, Corvis ST)影像的角膜轮廓中,由于角膜边缘的局部图像灰度分布相近这一特点,提取出的角膜轮廓普遍不完整或者提取的角膜轮廓边缘出现细小突出。这会使得角膜轮廓的完整性遭到破坏,提取到的角膜轮廓与实际的角膜原始图像严重不符。本文针对Corvis ST采集的角膜图像的轮廓提取问题,基于最大类间方差法(OTSU)算法设计一种高效的图像处理方法。首先,将角膜图像进行除杂、灰度化以及图像降噪等处理,达到减少图像计算量和降低数字图像噪声干扰的目的;其次,基于OTSU算法对图像进行分割,并在此基础上加入数学形态学运算,达到平滑图像边界和填充细小“孔洞”的目的;最后,采用Canny边缘检测算法提取图像中的角膜轮廓,达成提取出高完整性角膜轮廓的目的。在相同的图像数据集上,与最新的纽扣轮廓瑕疵检测系统中设计的轮廓提取算法(B-OTSU algorithm)进行了对比实验。实验结果表明,从轮廓完整性以及准确性的角度,应用本文方法提取的角膜轮廓明显优于最新的纽扣轮...     

上市公司“多次摘帽”的盈余管理行为研究

我国普遍存在大量ST企业出于“摘帽”动机采取各种盈余管理手段达到短期内的业绩提升,更有部分企业盈利情况常年在亏损边缘徘徊,在多次被ST和摘帽间长期游走,每次摘帽都并未从根本上增强企业自身的盈利能力。这种钻政策漏洞的行为不利于企业长期健康的发展,同时损害了投资者的利益,也极大地扰乱了资本市场的秩序。文章以WL公司为例,对其上市27年来“三次摘帽”过程中的盈余管理动机和手段加以剖析和揭露,并提出治理建议。     

基于PD64012 DIMM条的以太网远程供电

以太网供电（PoE）是当今一种非常流行的技术，它运用目前主流的网络传输介质——五类双绞线，实现了网络通信与电能同步传输的完美结合。基于该技术设计和实现了基于PD64012 DIMM条的以太网远程供电方案，已经取得较好的经济效益，并有着良好的社会应用前景。     

Development of sandwich enzyme-linked immunosorbent assay systems for plasma β-galactoside α2,6-sialyltransferase, a possible hepatic disease biomarker

Previous reports, including our work, have shown that plasma β-galactoside α2,6-sialyltransferase (ST6Gal I) activity is significantly increased in particular hepatopathological situations, suggesting that it may represent a sensitive biomarker for diagnosing hepatic diseases. So far, activity of ST6Gal I have been measured by using radioactive tracer method in place of measuring amount of ST6Gal I. However, this method is tangled and cannot exclude other sialyltransferase activities. Thus, simple and specific methods for measuring plasma ST6Gal I had been unavailable. Here, we developed two kinds of sandwich enzyme-linked immunosorbent assay (ELISA) systems that specifically detect the soluble cleaved form of ST6Gal I in plasma. In one sandwich ELISA, we detected rat specific sequence, EFQMPK, which is N-terminus of soluble ST6Gal I. In the other sandwich ELISA, we detected internal common sequence among rat, mouse and human ST6Gal I in plasma (M2 ELISA). Using the M2 ELISA, we observed that elevation of plasma ST6Gal I was much faster than elevation of plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in a carbon tetrachloride (CCl₄)-induced mouse liver injury model. Our data suggest that these ELISA systems are very useful tools for measuring plasma ST6Gal I, which represents a potential biomarker for diagnosing hepatic diseases.     

基于TMS320F2812的液晶显示模块SO12864设计

提出了一种基于DSP高速信号处理器控制实现LCD液晶显示的方案,介绍了DSP芯片TMS320F2812和液晶模块SO12864的功能特点,给出了TMS320F2812与液晶模块之间的接口设计。通过分析液晶模块的时序,阐述了在DSP中用软件编程模拟时序的方法,也即通过软件编程的方法解决了高速DSP处理器与慢速液晶模块之间时序不兼容的问题。通过在液晶上显示汉字,表明该系统显示效果良好,实现了对液晶模块SO12864的控制,完全达到了设计要求。