Three-dimensional atomic force microscopy based on tailored cantilever probe with flared tip

In order to meet the requirements of nondestructive testing of true 3D topography of micro-nano structures,a novel three-dimensional atomic force microscope(3D-AFM)based on flared tip is developed.A high-precision scanning platform is designed to achieve fast servo through moving probe and sample simultaneously,and several combined nanopositioning stages are used to guarantee linearity and orthogonality of displacement.To eliminate the signal deviation caused by AFM-head movement,a traceable optical lever system is designed for cantilever deformation detection.In addition,a method of tailoring the cantilever of commercial probe with flared tip is proposed to reduce the lateral force applied on the tip in measurement.The tailored probe is mounted on the 3D-AFM,and 3D imaging experiments are conducted on different samples by use of adaptive-angle scanning strategy.The results show the roob-mean-square value of the vertical displacement noise(RMS)of the prototype is less than 0.1 nm and the high/width measurement repeatability(peak-to-peak)is less than 2.5 nm.

Recording the direct surgeon’s view with an operating microscopic view improves microscopic ophthalmic surgery training

AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to facilitate the reproduction of a skilled surgeon’s technique by a surgeon in training.METHODS:A small camera was attached to the operating microscope with a custom adapter.Microscopic surgeon’s view and direct surgeon’s view through this new camera were recorded in the surgical recording system.Both movies were synchronized and analyzed how do surgeons handle the instruments.RESULTS:A small camera attached to the operating microscope allowed the surgeon’s hands motion to be recorded without interfering with the surgeon’s movements.Different surgeons used different methods to manipulate the ultrasound handpiece and the irrigation/aspiration device.Even in the simple paracentesis procedure,different surgeons used different methods.Surgeons-in-training were able to identify and improve their weaknesses by watching synchronized movies of their hand motions and microscopic view.CONCLUSION:Simultaneous recording the surgical field out of the operating microscopic view by a small camera set on the microscope is comprehensive and improves surgeons-in-training understanding and learning surgeries.

An experimental study on horizontal well waterflooding in the Cretaceous porous carbonate reservoir of Oman

Porous carbonate reservoirs,prevalent in the Middle East,are lithologically dominated by bioclastic limestones,exhibiting high porosity,low permeability,intricate pore structure,and strong heterogeneity.Waterflooding through horizontal wells is commonly used for exploiting these reservoirs.However,challenges persist,such as significant uncertainty and complex operational procedures regarding adjustment effects during the exploitation.The USH reservoir of the Cretaceous D oilfield,Oman exemplifies typical porous carbonate reservoirs.It initially underwent depletion drive using vertical wells,followed by horizontal well waterflooding in the late stage.Currently,the oilfield is confronted with substantial developmental challenges,involving the understanding of residual oil distribution,effective water cut control,and sustaining oil production since it has entered the late development stage.Employing a microscopic visualization displacement system equipped with electrodes,this study elucidated the waterflooding mechanisms and residual oil distribution in the late-stage development of the USH reservoir.The results reveal that the reservoir's vertical stacking patterns act as the main factor affecting the horizontal well waterflooding efficacy.Distinct water flow channels emerge under varying reservoir stacking patterns,with post-waterflooding residual oil predominantly distributed at the reservoir's top and bottom.The oil recovery can be enhanced by adjusting the waterflooding's flow line and intensity.The findings of this study will provide theoretical insights of waterflooding mechanisms and injection-production adjustments for exploiting other porous carbonate reservoirs in the Middle East through horizontal wells.

Quantitative determination of PFC3D microscopic parameters

It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the microscopic parameters of parallel-bonded particle model for three-dimensional discrete element particle flow code(PFC3D).Variation ranges of microscopic of the microscopic parameters are created by analyzing the effects of microscopic parameters on macroscopic parameters(elastic modulus E,Poisson ratio v,uniaxial compressive strengthσc,and ratio of crack initial stress to uniaxial compressive strengthσci/σc)in order to obtain the actual uniform design talbe.The calculation equations of the microscopic and macroscopic parameters of rock materials can be established by the actual uniform design table and the regression analysis and thus the PFC3D microscopic parameters can be quantitatively determined.The PFC3D simulated results of the intact and pre-cracked rock specimens under uniaxial and triaxial compressions(including the macroscopic mechanical parameters,stress−strain curves and failure process)are in good agreement with experimental results,which can prove the validity of the calculation equations of microscopic and macroscopic parameters.

Temporally Consistent Depth Map Estimation for 3D Video Generation and Coding

In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting function, which is obtained by block-based moving object detection and motion estimation with variable block sizes. Experimental results show that the proposed algorithm improves the temporal consistency of the depth video and reduces by about 38% both the flickering artefact in the synthesized view and the number of coding bits for depth video coding.

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

Scanning electron microscopic observation:three-dimensional architecture of the collagen in hepatic fibrosis rats

Background In the process of hepatic fibrosis, the accumulation of collagen fibers is strongly related to the hepatic function. The aim of this study was to investigate the three-dimensional architecture of the collagen network in the liver of rats with hepatic fibrosis. Methods Healthy adult male Wistar rats （n=32） were randomly divided into a control group （n=16） and a hepatic fibrosis group （n=16）. In the control group, the rats were treated with peanut oil while the rats in hepatic fibrosis group were treated for 10 weeks with 60% CCI4 diluted in peanut oil. The quantity of collagen fibers was detected by Western blotting; distribution of the collagen was detected by sirius red staining and polarized microscope; the three-dimensional architecture of collagen in the liver was observed under the scanning electron microscope after fixed tissues were treated with cell-maceration using NaOH. Statistical analysis was performed using the u test. Results The quantity of collagen fibers increased significantly in the hepatic fibrosis group. With the aggravation of hepatic fibrosis, collagen fibers gradually accumulated. They interlaced the reticulation compartment and formed a round or ellipse liver tissue conglomeration like a grape framework that was disparate and wrapped up the normal liver Iobule. The deposition of collagen fibers was obvious in adjacent hepatic parenchyma, especially around the portal tracts. Conclusion Our experiment showed the collagen proliferation and displays clearly the three-dimensional architecture of collagen fibers in rat liver with hepatic fibrosis by scanning electron microscope. It can provide a morphological foundation for the mechanisms of changed haemodynamics and portal hypertension in hepatic fibrosis.

弹力竹节纱捻度循环规律及测量方法

弹力竹节纱作为花式纱中品种繁多的一类,视觉效应独树一帜。中国没有弹力竹节纱捻度测量的相关标准,这给弹力竹节纱力学性能的评定和织物成型带来诸多技术难题。提出一种弹力竹节纱的捻度测量方法:在(0.75±0.10)cN/tex张力条件下,将自然伸直的纱线均匀缠绕于标准黑板上,再置于视频显微镜下采集图像,测得捻角和纱线直径后通过公式换算得出捻度。结果显示:该方法可以测量不同张力下弹力竹节纱的捻度;与直接计数法、退捻加捻法相结合,还可以分析捻度循环的总长度、弹力竹节纱捻度的分布规律以及捻度分布对纱线强力的影响。

便携式视频显微镜光源的改造

目的:改造便携式视频显微镜的光源,以获得充足的照明。方法:改造LED手电筒灯头为vibao-v36 USB便携式显微镜照明;自主设计、定制LED灯头或同轴光纤接头为Tetracam ZTC-305便携式数字显微镜照明。结果:vibao-v36 USB便携式显微镜可采用改造的LED手电筒灯头照明;Tetracam ZTC-305可采用自主设计、定制的LED灯头或同轴光纤接头照明。结论:便携式视频显微镜的光源经过改造,能够为远距离手术操作提供充足的照明。

稻米垩白三维切面的遗传分析

以典型的籼 /粳交 (窄叶青 8号 /京系 17) DH群体为材料 ,采用视频显微扫描技术和计算机图形分析相结合的技术手段 ,从横切面、侧面和腹面 3个层面对 12 7个 DH株系的垩白大小进行了立体分析 ;并结合该群体业已构建的染色体图谱检测控制垩白的数量性状位点 (QTL)。对横切面的分析检测到 3个 QTL s,分别位于第 8、11和 12染色体上的 RZ6 17～G2 132、ATT42 B～ RG98和 CT46 2～ RG5 74标记区间内。对侧面的分析也检测到 3个 QTL s,其 L OD值的最高峰位点与横切面分析完全一致。对腹面的分析检测到 3个 QTL s,分别位于第 8、11和 12染色体上的 GA376～ CT195、RZ6 38～ RG30 4和CT46 2～ RG5 74标记区间内 ,其加性效应来源与横切面和腹面分析的一致。 3个切面的有关 QTL的 LOD值的分布峰区和最高峰位点的一致或相互覆盖也表明 ,应用视频显微扫描技术分析稻米垩白任一切面的数据均可定位控制垩白大小的 QTL。

基于PVM的可视化水合物生成实验

借助粒子视频显微镜(Particle Video Microscope,PVM)对水合物高压实验环路中的油包水乳状液混合以及水合物的生成、聚结过程进行了实验研究。结果表明:PVM设备可以清晰、定量、视觉化地检测到水合物的生成结晶过程以及实时颗粒/液滴的粒径分布,并发现随着水合物的不断生成,其水合物颗粒会发生聚结,形成较大的水合物颗粒,随着反应的进一步进行,水合物颗粒粒径会表现为先增大后减小的趋势,这主要是由于水合物生成过程中的颗粒、液滴间的碰撞、聚集使得粒径增大,同时体系中增强的剪切作用和水合物颗粒表面润湿性的减小致使聚集的水合物颗粒又发生破碎所致;再则,实验过程中阻聚剂的加入对油水乳状液具有较好的乳化作用,使其水相较为均匀的分散到连续油相中,形成稳定、均一的乳状液体系,并且其分散相水滴的粒径要较不加剂情况下少;在水合物的形成过程中水合物颗粒间的聚并是导致水合物堵塞管道的主要原因。

便携式视频显微镜经大脑纵裂胼胝体上段、经胼体入路的解剖研究

目的研究便携式视频显微镜经大脑纵裂胼胝体上段、经胼胝体入路的显露范围和观察效果。方法将新鲜和灌注固定的成人尸头标本各5例,在便携式视频显微镜下,经大脑纵裂胼胝体上段、经胼胝体入路暴露并观察侧脑室和第三脑室。结果经大脑纵裂胼胝体上段、经胼胝体入路,在便携式视频显微镜下解剖观察,侧脑室和第三脑室的结构显示清楚,图像逼真。结论便携式视频显微镜经大脑纵裂胼胝体上段、经胼胝体入路能够完成侧脑室和第三脑室的显微解剖。

基于 FIFO 存储器的高速显微图像处理系统

论述了在显微成像系统中采用普通视频采集卡所存在的问题，并介绍了一种基于ＦＩＦＯ存储器结构的高速显微图像处理系统的原理和设计，进而从硬件和软件两个方面详细地说明了系统的体系结构。

视频显示的小尺寸工件精密测量方法

传统的显微测量视场小,操作繁琐,读数与定位存在人员的主观误差。针对这些缺点,设计了一种机器视觉与显微测量相结合的测量系统。该系统利用显微镜和视频显示的放大作用,光栅测微仪测量的精准性,实时检测被测工件的倒角位置,在人工干预下实现了高精度测量。对一般的测量显微镜进行改装,采用双屏幕显示。既有效的利用了摄像机的分辨率,使测量视场可以满屏显示,又使得计算机进行倒角测量的同时可以采集并显示其它参数测量模块的数据,实现一机多用,因此具有较高的性价比。对特殊工件尺寸的精密测量具有实用价值。

合金钢焊接区扩散氢的动态分布

对４种低合金钢采用显微镜下录像测氢法研究焊接区扩散氢的逸出动态过程及其分布规律。结果表明，扩散氢在焊接区呈变形正弦曲线分布；在组织状态发生变化的结合部位存在氢的局部聚集。其聚集程度与焊接区的应力集中状况及显微组织的不均匀性有关。

合金钢焊接区显微组织与扩散氢的动态分布关系

运用显微镜下录像测氢法研究了４种不同预处理状态下的国产低合金高强钠焊接区扩散氢动态分布的规律。结合焊接接头不同组织区的硬度及金相分析，发现扩散氢在熔合区及粗晶区与细晶区交界处存在局部聚集，扩散氢呈变形正弦曲线分布。研究纺果表明：焊接区氢陷井的不均匀分布是造成扩散氢局部聚集的主要原因。这对于工程实践中防止焊接冷裂纹产生以及进一步分析焊接冷裂纹的形成机理提供了理论依据。

便携式视频显微镜经耳后(乙状窦后)入路的解剖研究

目的研究便携式视频显微镜经耳后(枕下乙状窦后)入路的显露范围和观察效果。方法新鲜和灌注固定的成人尸头标本各3例(6侧),耳后皮肤弧形切口,游离骨瓣开颅;经枕下乙状窦后入路,在便携式视频显微镜下暴露并观察桥小脑角。结果便携式视频显微镜经耳后(枕下乙状窦后)入路能够清楚、逼真地暴露桥小脑角。结论在便携式视频显微镜的视屏图像引导下,经耳后(枕下乙状窦后)入路能够完成桥小脑角的显微解剖。

精子泳动速度和尾鞭打频率测定

本文报告用显微摄像监视系统测定107例(生育组30例、不育组77例)精液的精子泳运速度,生育组25.09±4.36μm/s;不育组18.02±4.62μm/s,两组 t 检验具显著差异(t=6.71,P<0.01)。用相差显微镜测定精子尾部摆动(鞭打)频率,生育组7.85±1.29Hz;不育组6.09±11.36Hz,两组 t 检验具显著差异(t=5.88,P<0.01)。精子泳动速度和尾鞭打频率呈密切相关(r=0.83)。

视频内窥镜技术在火箭管路上的应用

为检测火箭增压输送管路内表面缺陷,提高管路质量,开展了内窥镜技术在火箭管路内表面应用技术研究。介绍了内窥镜设备技术特点,内窥镜管路检测存在问题,设备探头选择和尺寸测量校准的工艺方法,对检测出的内表面缺陷类型进行归类总结,对难以定性的缺陷利用电镜和金相等技术进行微观分析。结果显示:采用视频内窥镜检测技术对火箭管路内表面进行检测时,应根据增压输送管路的内径尺寸优先选择直径较大的探头;采用标定缺陷对比法进行测量校准,其测量准确,现场检测适用性强;检测缺陷图像清晰,效果稳定,内表面缺陷类型定性准确,检测效果满足工艺要求。

立体影像技术在耳显微外科教学中的应用

由于颞骨解剖结构的复杂性及平面媒介教学模式的限制,优秀耳外科医师培养困难且周期漫长。耳显微外科立体图谱的开发及立体手术视频系统的应用,可明显提高耳科教学及研究效果,有效用于指导年轻医师手术训练,具有广泛应用前景及推广价值。