声触诊组织成像定量技术与声触诊组织定量技术鉴别BI-RADS 4级乳腺病变良恶性的价值

目的 :比较声触诊组织成像定量(virtual touch tissue imaging quantification, VTIQ)技术和声触诊组织定量(virtual touch tissue quantification,VTQ)技术鉴别诊断BI-RADS 4级乳腺肿块良恶性的价值。方法 :选取常规超声诊断为BI-RADS 4级的乳腺肿块患者90例,共101个病灶。进行VTQ和VTIQ检查,记录病灶内部剪切波速度(SWV)。以病理结果为金标准,分别比较两种方法检测乳腺肿块良恶性SWV的差异,绘制受试者工作特征(ROC)曲线,确定最佳诊断界值,并评价两种方法的诊断效能。结果:101个乳腺病灶病理证实恶性结节42个,良性结节59个。VTIQ技术检测的良性、恶性病灶SWV分别为(2.92±1.06)m/s、(5.45±1.76)m/s。VTQ技术测得的良性、恶性病灶SWV分别为(2.85±1.06)m/s、(5.22±2.02)m/s。两种方法测得恶性病灶的SWV均高于良性病灶,差异均有统计学意义(P <0.05)。两种方法的ROC曲线下面积(AUC)分别为0.867、0.848,差异无统计学意义(P> 0.05)。当VTIQ界值取3.96m/s时、VTQ界值取3.71m/s时,诊断效能最佳,其灵敏度、特异度、准确率、阳性预测值和阴性预测值分别为85.71%、88.14%、87.13%、83.72%和89.66%;78.57%、72.88%、75.25%、67.35%和82.69%,VTIQ特异度和准确率高于VTQ,组间差异具有统计学意义(P <0.05)。结论 :VTIQ在BI-RADS 4级乳腺肿块良恶性的鉴别诊断中,具有较高的临床应用价值,其特异度和准确率高于VTQ。     

声发射技术在压力容器检验当中的应用价值分析

压力容器在制造过程中需要焊接的部位非常多,且由于工作环境的恶劣,容易出现腐蚀、裂纹,对压力容器的使用性能造成影响,导致引发安全事故。为了确保生产安全,需要采用有效的检验方法对使用中的压力容器进行定期检验,避免安全事故的发生,本文主要针对声发射技术在压力容器检验中的应用价值进行分析。     

微量润滑技术对切削Ti-6Al-4V组织性能的影响

通过温度采集、力学性能检测和组织形貌分析,系统研究了微量润滑切削TC4钛合金时不同润滑油用量对冷却效果、切削性能和组织性能的影响规律。试验结果表明:同一切削条件下,润滑油用量Q在一定范围内值越大,冷却效果、切削性能越佳,加工后材料显微组织尺寸越小,显微硬度越大;当Q取值35-40ml/h时,各性能趋于最优。然而,Q超过40ml/h后,冷却效果、切削性能和工件的组织性能反而降低。     

成型尺寸对电子束选区熔化成型TC4合金性能与组织的影响

采用电子束选区熔化制造技术制备不同成型尺寸的Ti-6Al-4V(TC4)钛合金试样,通过金相显微镜、扫描电镜、万能试验机和X射线衍射仪等研究设备,探究了不同成型尺寸对电子束选区熔化成型TC4钛合金试样的显微组织与力学性能的影响。结果表明：在R05、R06和R07这3种不同成型尺寸的试样中,成型尺寸越大,则拉伸强度和屈服强度越大,同时弹性模量和延伸率越小,即塑性越差;试样R05、R06和R07均发生韧窝断裂,但试样R05断口塑性较差,更接近脆性断裂;试样R07上下段分别形成双态组织和等轴组织,且距离打印基板位置越远,试样的层间结合率和粉末熔化率越低,即打印情况越差;对于成型尺寸最大的试样R05,由于其每层扫描时间长、热传递效果好,故其β柱状晶内形成了细针状马氏体和魏氏组织,而成型尺寸较小的R06试样则由于较高加工温度中的冷却,形成了网篮组织和片状α相组织。     

充氢对多孔TC4钛合金室温组织的影响

利用管式氢处理炉,采取固态气相渗氢法对多孔TC4钛合金进行充氢试验。采用光学显微镜、X射线衍射和扫描电镜等手段,研究相对密度、充氢温度和充氢时间对多孔TC4钛合金的相组成及微观组织的影响。研究结果表明,随氢质量分数的增加,多孔TC4钛合金的α相逐渐减少,β相逐渐增多,并形成δ氢化物;充氢温度达到某一临界温度时,一定量的氢可诱发多孔TC4钛合金的马氏体转变,生成α'马氏体;充氢后多孔TC4钛合金由原始等轴组织转变为针状和片层状的细小组织,当充氢温度较高氢质量分数较高时,出现片层状α'马氏体组织,当充氢温度较低氢质量分数较高时则出现网篮状α片层组织。充氢多孔TC4钛合金的微观组织与氢质量分数相当的TC4钛合金粉末相比整体要细小。     

置氢Ti-6Al-4V合金组织演变及其对切屑形成的影响

利用金相显微镜、X射线衍射仪和SEM对置氢Ti-6Al-4V合金材料微观组织及切屑形貌进行了观察分析,通过室温压缩实验测试置氢钛合金力学性能,探讨了置氢Ti-6Al-4V组织、力学性能与切屑形态之间的联系,研究了置氢Ti-6Al-4V合金组织演变及其对切屑形成的影响.结果表明:氢含量为0.6wt%时,钛合金置氢炉冷后组...     

固态渗碳化硼对Ti-6Al-4V显微组织和性能的影响

研究了Ti-6Al-4V在800℃和1000C下固态渗碳化硼20h后的渗层显微组织以及对硬度等的影响。结果表明：渗层在表面为致密分布的化合物层,其成分主要为TiC、TiB以及TiB2等硬质相,而在基体内部则形成沿晶界分布的板条状或等轴状的颗粒扩散层;表面碳化硼处理可以显著提高Ti-6Al-4V的表面硬度,由359HV提高到了664HV,并且可以得到良好的表面硬、芯部软的硬度梯度;断口形貌分析发现材料由韧性断裂转变成脆性断裂。     

时效温度对17-4PH钢微观组织及力学性能的影响

采用光学显微镜(OM)、扫描电镜(SEM)、电子万能试验机等方法研究了不同热处理工艺对17-4PH马氏体不锈钢组织和力学性能的影响规律。实验结果表明：热处理后基体中的析出相对时效温度变化比较敏感,尺寸随时效温度升高而增大。固溶+时效处理的试样与原始样相比其硬度和抗拉强度显著提升,而塑性无明显变化。此外,1040℃固溶+470℃时效后的试样综合力学性能最好。     

BI-RADS联合UE技术对小乳腺癌的诊断价值分析

目的 分析乳腺影像报告与数据系统(BI-RADS)联合超声弹性成像(UE)技术对小乳腺癌的诊断价值.方法 以我院乳腺科2018年1月～2020年2月收治的274例乳腺肿块患者为研究对象,所有患者均进行病理检查,根据病理检查结果分为乳腺增生患者(165例)和小乳腺癌(109例)患者,比较乳腺增生患者和小乳腺癌患者BI-R...     

Application of acoustic emission technique for the detection of defects in rolling element bearings

The usefulness of acoustic emission (AE) measurements for the detection of defects in roller bearings has been investigated in the present study. Defects were simulated in the roller and inner race of the bearings by the spark erosion method. AE of bearings without defect and with defects of different sizes has been measured. For small defect sizes, ringdown counts of AE signal has been found to be a very good parameter for the detection of defects both in the inner race and roller of the bearings tested. However, the counts stopped increasing after a certain defect size. Distributions of events by ringdown counts and peak amplitudes are also found to be good indicators of bearing defect detection. With a defect on a bearing element, the distributions of events tend to be over a wider range of peak amplitudes and counts.     

4×4电容式触摸键盘的设计与实现

随着电子技术的发展,触摸按键作为一种接口技术在电子产品中得到了广泛的应用,由于电容式触摸按键具有寿命长、无机械磨损、易清洁、防水防污等特点,深受用户欢迎。该文结合电容触摸按键的原理,利用STM32单片机通用定时器的输入捕获功能,设计实现了4×4电容式触摸键盘系统。经测试,电路具有较高的可靠性。     

管道泄漏检测方法研究综述

管道泄漏常常造成环境污染、财产损失和人员伤亡,由于其发生的隐蔽性,对管道泄漏的及时识别与准确定位具有重要的现实意义。按照结构损伤识别方法的分类标准,将管道泄漏检测方法分为基于模型的方法、基于信号处理的方法和基于人工智能的方法。围绕这3类方法,分别重点介绍了管道泄漏固体模型、流体模型、泄漏信号识别和定位处理方法、人工神经网络,以及支持向量机辨识管道泄漏方法的国内外研究现状,梳理了众多文献间的区别和联系。最后分析了各检测方法存在的不足,对未来管道泄漏检测研究方向进行了展望。     

几种气动发信元件的应用

文章针对气动程序控制系统,介绍几种常用的气动发信装置的应用与特点,并以相应的典型回路加以说明。     

Intelligent diagnostic technique of machining state for grinding

Successful grinding of a final product depends upon a large number of parameters that affect the grinding result and are strongly interlinked. It is, therefore, difficult to detect directly the generation of grinding faults such as chatter vibration and burning. In this paper, to achieve the development of an intelligent diagnostic technique for chatter vibration and burning phenomena on grinding process, acoustic emission signals were processed and signal parameters of the acoustic emission were also determined. In addition, a neural network was used as a diagnostic technique of the grinding state. A momentum coefficient, learning rate, and structure of the hidden layer were determined during the iterative learning process and the performance of the diagnostic technique was evaluated.     

Potentialities of acoustic emission technique for inspection of main pipelines

A technique has been suggested for calculating parameters of acoustic emission pulses propagating in a main pipeline as functions of parameters of developing cracks, pumped products, pipeline dimensions, and a distance to the detector position. Limiting distances for detection of acoustic emission pulses and minimal dimensions of detected cracks have been estimated.     

Development of the technique of clustering by acoustic emission signal parameters

The technique of clustering by a set of parameters of acoustic emission (AE) signals, which allows reducing the time of processing of the recorded data, is considered. A comparative analysis of the stability of three clustering techniques (by shape, leading edge rise rate, and a set of AE signal parameters) with respect to the effect of random noise distributed according to a normal law is performed. A possibility of using the considered clustering techniques for distinguishing different stages of duralumin specimen fractures and during welding of steel specimens is experimentally demonstrated.     

Applications of quantitative digital image analysis to breast cancer research

Our studies of radiogenic carcinogenesis in mouse and human models of breast cancer are based on the view that cell phenotype, microenvironment composition, communication between cells and within the microenvironment are important factors in the development of breast cancer. This is complicated in the mammary gland by its postnatal development, cyclic evolution via pregnancy and involution, and dynamic remodeling of epithelial-stromal interactions, all of which contribute to breast cancer susceptibility. Microscopy is the tool of choice to examine cells in context. Specific features can be defined using probes, antibodies, immunofluorescence, and image analysis to measure protein distribution, cell composition, and genomic instability in human and mouse models of breast cancer. We discuss the integration of image acquisition, analysis, and annotation to efficiently analyze large amounts of image data. In the future, cell and tissue image-based studies will be facilitated by a bioinformatics strategy that generates multidimensional databases of quantitative information derived from molecular, immunological, and morphological probes at multiple resolutions. This approach will facilitate the construction of an in vivo phenotype database necessary for understanding when, where, and how normal cells become cancer.