Acoustic Non-Destructive Testing Technology in Concrete Bridge Inspection and Pile Foundation Detection

This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.

Discussion on the Status Quo of Non-Destructive Testing Technology in Highway Engineering and Strategies of Improving the Quality of Testing

Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.

A coin-tap method of composite materials non-destructive testing based on improved grey clustering

Aiming at the problems of low reliability and complex operation of traditional coin-tap test of composite material,this paper introduces the grey system theory and achieves better performance.The response signals of coin-tap are classified through the grey clustering based on relation analysis,and corresponding improvements are made to the calculation method of the relation degree of nearness.First,the time history of acceleration is taken as the system behavior sequence.The improved correlation calculation method is used to solve the relation degree of nearness between the sequences,and the matrix of degree of grey relation is constructed based on this.Then,the sequence groups are summarized through the matrix,and the response signals of coin-tap are qualitatively classified according to the location of the reference sequence.Finally,the defect detection of composite materials is completed without pre-testing.The test results show that the accuracy of the coin-tap test based on improved grey clustering reaches 100%,which simplifies the operation steps while ensuring the reliability of the coin-tap test results.

55 Years of Holographic Non-Destructive Testing and Experimental Stress Analysis:Is there still Progress to be expected?

Holographic methods for non-destructive testing,shape measurement,and experimental stress analysis have shown to be versatile tools for the solution of many inspection problems.Their main advantages are the non-contact nature,the non-destructive and areal working principle,the fast response,high sensitivity,resolution and precision.In contrast to conventional optical techniques such as classical interferometry,the holographic principle of wavefront storage and reconstruction makes it possible to investigate objects with rough surfaces.Consequently,the response of various classes of products on operational or artificial load can be examined very elegantly.The paper looks back to the history of holographic metrology,honors the inventors of the main principles,discusses criteria for the selection of a proper inspection method,and shows exemplary applications.However,the main focus is on modern developments that are inspired by the rapid technological process in sensing technology and digitization,on current applications and future challenges.

Performance of common imaging techniques vs serum biomarkers in assessing fibrosis in patients with chronic hepatitis B: A systematic review and meta-analysis

BACKGROUND Noninvasive biomarkers have been developed to predict hepatitis B virus(HBV)related fibrosis owing to the significant limitations of liver biopsy.Both serum biomarkers and imaging techniques have shown promising results and may improve the evaluation of liver fibrosis.However,most of the previous studies focused on the diagnostic effects of various imaging techniques on fibrosis in all chronic liver diseases.AIM To compare the performance of common imaging methods and serum biomarkers for prediction of significant fibrosis caused only by HBV infection.METHODS A systematic review was conducted on the records available in PubMed,EMBASE,and the Cochrane Library electronic databases until December 2018.We systematically assessed the effectiveness of two serum biomarkers and three imagine techniques in predicting significant fibrosis solely caused by HBV infection.The serum biomarkers included aspartate aminotransferase-to-platelet ratio index(APRI)and fibrosis index based on the 4 factors(FIB-4).The three imaging techniques included acoustic radiation force impulse(ARFI),FibroScan,and magnetic resonance elastography(MRE).Three parameters,the area under the summary receiver operating characteristic curve(AUSROC),the summary diagnostic odds ratio,and the summary sensitivity and specificity,were used to examine the accuracy of all tests for liver fibrosis.RESULTS Out of 2831 articles evaluated for eligibility,204 satisfied the predetermined inclusion criteria for this current meta-analysis.Eventually,our final data contained 81 studies.The AUSROCs of serum biomarkers of APRI and FIB-4 were both 0.75.For imaging techniques(ARFI,FibroScan,and MRE),the areas were 0.89,0.83,and 0.97,respectively.The heterogeneities of ARFI and FibroScan were statistically significant(I2>50%).The publication bias was not observed in any of the serum biomarkers or imaging methods.CONCLUSION These five methods have attained an acceptable level of diagnostic accuracy.Imaging techniques,MRE in particular,demonstrate significant advantages in accurately predicting HBV-related significant fibrosis,while serum biomarkers are admissible methods.

Technologic Tests of Turkey-Gordes Zeolite Minerals

Natural zeolites are found at many points of the world in the form of minerals. As for Turkey, quite large volumes of zeolites reserves are available in the following regions: Ankara (Nallihan, Beypazari, Polatli etc.), Kütahya-Sa- phane, Manisa-Gordes, Manisa-Demirci, Izmir-Urla, Balikesir-Bigadiçand Cappadocia. By means of the works carried out only at the field in Balikesir- Bigadiçregion, one of the detected reserves in Turkey, it was understood that an easily workable potential around 500 million ton is available. According to the very limited observations made until today, it is stated that the total reserve in our country may be around 500 billion ton. In these regions, the types of clinoptilolite, hoylandit, chabazite, analcime and erionite from the zeolite minerals exist. Zeolites are widely used in many sectors such as energy, environment, construction, detergent, chemistry, medicine, mining, agriculture and livestock. Zeolites also provide great benefits when they are used especially in agriculture and livestock for the purpose of preventing environmental pollution threatening human being. In this study, zeolite sample taken from Manisa-Gördes region was used. Following the processes of crushing and sieving, zeolite sample was subjected to chemical analyses according to their grain thickness, microscopic examination, the analyses of XRD and Technological Tests (ceramic pre-technological reviews, value of oil absorption, whiteness measurements, examination of the zeolite sample as cat litter, determination of bleaching capability, porosity values) and their ore characteristics were determined. After the analyses, ferrous oxide, biotite, quartz, muscovite, feldspar, chlorite, non-zeolite silicates and metamorphic rock fragments have been found. This zeolite mineral with high mineral purity has been suggested to clear off all impurities via ore preparation and enrichment methods.

电镜表征公共服务实验室的开放运行与实践

“材料测试分析中心”的电镜表征实验室是依托于“双一流”建设学科的校院两级共建具有公共服务性质的校级注册实验室。经过多年的实验室开放运行,逐渐形成了从测试分析服务、支撑实验教学到实验创新开发的高效化、标准化和规范化管理运作模式。一方面,实验室可提供优质的测试分析服务,保证高质量的实验数据,有力支撑高校科研团队实验研究并助力与校外单位的技术合作;另一方面,实验室承担高素质人才培养的工作,在实验技术与设备培训、实验教学建设与改革、实践技术指导与分析支持中发挥着举足轻重的作用。结合实验室开放服务的关键管理和技术问题,创新实验管理方法、标准化实验工艺流程以及仪器设备功能开发,提高了实验室运行的开放效率,提升了实验技术人员的服务能力。

重载铁路桥梁体外预应力筋加固性能研究

运营提载会导致重载铁路桥梁损伤累积和刚度退化加剧,对重载铁路预应力混凝土桥梁进行加固可以改善桥梁的受力状况,提高桥梁承载能力。为了研究重载铁路桥梁体外预应力筋加固的性能,分别制作重载铁路24 m超低高度预应力混凝土梁的未加固足尺试验模型与体外预应力筋加固足尺试验模型,并开展200万次疲劳试验与疲劳后静力试验。建立未加固预应力混凝土梁与体外预应力筋加固预应力混凝土梁的精细化有限元模型,通过试验与有限元分析,研究加固前后重载铁路预应力混凝土梁的静力与疲劳性能,揭示加固前后梁体挠度和应力变化规律,并分析不同轴重列车作用下加固预应力混凝土梁的力学性能。研究结果表明:重载铁路桥梁外加预应力筋的加固效果良好,疲劳试验中加固梁刚度退化幅度、跨中挠度、梁内预应力筋应力、梁底及下翼缘混凝土应力显著比未加固梁的小;在33 t轴重列车与1.2倍中等荷载(ZH)轴重作用下,外加预应力筋加固的24 m超低高度预应力混凝土梁的适应性良好,预应力混凝土梁挠度与应力响应均符合规范要求。研究结果可为重载铁路桥梁的设计、养护、维护与加固提供基础与参考。

食品检测中近红外光谱分析技术的应用研究

为了实现对食品成分、品质等方面的准确检测,为食品安全监管和质量控制提供有效的技术支持,引入近红外光谱分析技术,开展了该项技术在食品检测中的应用研究。通过样品制备、选择光谱采集设备、设置采集参数,采集食品近红外光谱,引入标准正态变量变换算法和自适应滤波算法,预处理采集的光谱数据,基于预处理后的数据,结合主成分分析法,构建食品成分特征与近红外光谱数据之间的数学模型,实现近红外光谱分析技术在食品检测的应用设计。实验结果表明,提出的研究应用后,食品成分检测结果与真实值更加接近,检测均方根误差较小,食品检测的准确性得到了显著提升。

研究生“现代分析测试技术”课程建设的改革探索与实践

依托广东工业大学“现代分析测试技术”研究生课程建设的改革与实践,从课程的教学内容、教学方法、教学条件和教学效果等方面,提出通过构建多层次、广范围的课程内容体系结构,灵活应用多种形式相结合的立体化教学模式,实施基于项目的综合性仪器分析设计教学环节,建立稳定的课程教学团队与完整的课程教学资源,构建完备的课程网络教学环境等课程建设改革方法与举措,探索在研究生课程中实现课程基础性与创新性双结合和理论学习与实践学习一体化的特色。

地下管廊抗震研究现状综述

针对地下管廊工程建设高速发展、抗震减灾需求愈发凸显的现状,综述地下管廊抗震研究现状.首先,通过国内外以往的震害实例,对地下管廊的震害形式、震害影响因素及震害机理进行了系统性总结.其次,从拟静力试验和振动台试验两个方面总结了地下管廊抗震性能的试验研究现状.再次,总结了地下管廊抗震分析的简化分析方法、动力时程方法、地震易损性评估及减隔震技术的研究现状.最后,基于文献综述提出了目前地下管廊抗震研究亟待解决的问题并做出展望,以期促进地下管廊抗震研究的发展.研究表明:地下管廊在地震作用下的破坏形式主要有混凝土剥落、裂缝贯通、接缝错位或张开、管廊受剪断裂等;地震作用下地下管廊穿越非均匀场地时动力响应的放大效应显著,地下管廊穿越软硬交互等非均匀场地时的抗震性能研究值得重视;交叉节点是地下管廊的薄弱环节,交叉管廊的抗震设计方法研究值得关注;预制管廊接头易受到地震破坏,不同类型预制管廊接头的抗震性能研究需深入探索;城市大型地下管廊系统抗震性能受到不同交叉节点和不同管廊之间的交互影响,高效的地下管廊系统建模方法和高效的简化分析方法亟待研究;城市大型地下管廊系统地震易损性分析是重要的发展方向;地下管廊的减隔震技术值得发展.

机载激光雷达测量技术在冰川科学观测中的应用研究

冰川作为“固态水库”其融水对我国西北干旱地区区域水资源利用和生态系统可持续发展都具有重要意义,开展冰川科学研究并努力探索冰川研究新技术、新方法至关重要。本文基于机载激光雷达测量技术在冰川科学观测中的应用研究,从航空测量经验、冰川试验区域气象条件及航飞设备三方面开展冰川航测可行性分析及技术方法论证。结果表明,冰川激光雷达数据平面及高程误差绝对值均以≤10 cm为主,占比分别为86.6%(X方向)、86.5%(Y方向)、66.6%(XY方向)、90.0%(Z方向),误差值满足冰川观测要求。此次冰川试验验证了机载激光雷达测量技术在冰川科学观测中的可行性,实现了高海拔、高落差、极端天气地区航空测量技术突破,为促进我国冰川科学研究发展增添新动力。

大型起重机数字化检测技术开发与研究

拟利用起重机振动检测、无损检测、金属结构在线应力检测、起重机电气控制系统检测、数据库技术、智能分析软件等技术手段,基于起重机基本信息数据、技术参数数据、检验数据、维保数据、物联网设备采集数据等多维度数据,研究出一套针对大型起重机的数字化检测技术,并通过对大数据的分析,制定出有针对性的起重机使用意见、维护保养意见和使用寿命监测意见,从而进一步提高大型起重机的工作效率、降低起重机安全事故的发生频率,为起重机带来更好的使用性能、为操作人员带来安全保障、为企业带来经济效益、为政府带来社会效益。

Relating estimates of wood properties of birch to stem form, age and species

Birch has long suffered from a lack of active forest management,leading many researchers to use mate-rial without a detailed management history.Data collected from three birch(Betula pendula Roth,B.pubescens Ehrh.)sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood proper-ties that could be explained by stand history,tree age and stem form.All sites were genetics trials established in the same way.Estimates of acoustic velocity(AV)from non-destructive testing(NDT)and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered.A subsample of stems had radial profiles of X-ray wood density and ring width by year created,and wood density was related to ring number from the pith and ring width.It seemed likely that wood density was negatively related to ring width for both birch species.Linear models had slight improvements if site and species were included,but only the youngest site with trees at age 15 had both birch species.This paper indicated that NDT values need to be considered separately,and any predictive models will likely be improved if they are specific to the site and birch species measured.

数字建设与高校科技创新效率协调发展分析

采用熵值赋权法、全局DEA-EBM模型、α收敛模型、β收敛模型和耦合协调模型测度评价2011—2021年中国31个省份数字建设水平和高校科技创新效率,并检验数字建设对高校科技创新效率的驱动耦合效应。研究发现,全国(未含港澳台地区)高校科技创新效率较低,总体呈波动下降趋势,并且东部地区下降幅度远超中西部地区;数字建设能有效驱动高校科技创新效率提升,加速各省份间高校科技创新效率差距的收敛速度,并且对东部地区的驱动作用力明显强于中西部地区;全国数字建设与高校科技创新效率间的耦合协调度总体呈稳定上升趋势,但东部地区耦合值明显高于中西部地区,东部地区早已进入初级协调阶段,并逐渐迈向中级协调状态,而中西部地区整体仍处于濒临失调阶段,近年来才逐渐转向勉强协调状态。由此从促进高校科技创新效率提升、推动数字建设发展和加强两者协同水平等方面提出相关建议。

电机无级调节的振动抑制自动平衡测控系统

针对旋转机械转子系统在实际运转中不停机的情况下振动值超标的问题,提出了一种机电式自动平衡综合测控系统,可对转子系统的振动进行主动精稳靶向抑制。首先,自主设计自动平衡执行器并开发了机电式自动平衡执行器无错调驱动控制算法,该算法通过可编程逻辑控制器(programmable logic controller,简称PLC)编程实现;其次,通过安装于转子轴端的自动平衡执行机构,结合上位机程序测控系统,能够在设备运行过程中实时监测转子不平衡振动并进行主动自动平衡,具备更大的配重占比和更优的电磁兼容性,可实现配重的无级调节;最后,对算法进行了仿真及现场不同转速下的自动平衡测试验证。结果表明,机电式自动平衡执行器降振仿真能达到很好的平衡效果,现场试验不同转速下均具备90%以上的降振能力,具有重要的应用价值。

基于微生物诱导碳酸钙沉淀技术加固珊瑚砂试验研究

微生物诱导碳酸钙沉淀技术(MICP)广泛应用于土木工程领域,为更好地了解微生物加固钙质砂场地的作用效果,本文通过采用低pH一相注浆加固的方法,开展对加固后的钙质砂场地的室内分析测试以及现场加载测试。通过钻孔取样开展了无侧限压缩试验、剪切波速试验以及扫描电镜试验。试验结果表明,在相同的加固条件下,碳酸钙沉淀作用形式不同将会导致较大的强度差异性;现场加载试验在微生物场地加固、养护结束后,且场地保持干燥时进行平板载荷试验,通过荷载板试验可以发现,当荷载逐渐增大时,承压板周边土开始出现裂缝延展,最终破坏时土体发生了较大的位移沉降和裂缝扩展,也证明了携带菌种现场扩培的方法在岛礁微生物加固中的可取性。

化学技术在食品安全检测中的应用分析

新形势下,与新时代人民群众对美好生活的需要相比,食品安全工作仍面临不少问题和困难。强化食品安全监管,化学技术被广泛应用于食品安全检测中。在技术原理上,化学技术在食品安全检测中常用到色谱法、光谱法、波谱法和比色分析法。在现实应用中,化学技术在农药残留、兽药残留和食品添加剂等安全检测中优势明显。

道路桥梁检测中的无损检测技术运用

为实现道路桥梁质量管理,分析道路桥梁检测中的无损检测技术运用效果,以某道路桥梁为例展开相关研究,结合实际情况,选择超声波检测方法进行检测,并按照检测流程实现道路桥梁混凝土路面结构和桩基结构的无损检测,获取两者的检测结果。依据分析结果可知:超声波无损检测方法在道路桥梁检测中,具备较好的应用效果,满足其无损检测需求。

探索VR技术在材料分析测试技术课程中的应用与潜力

材料分析测试技术是材料科学研究的必要表征手段,对于现代科学技术的推动起着重要的作用。传统的课堂教学方式已经无法满足学生对实践操作的需求,各种材料的分析测试方法是十分复杂且抽象的,而基于VR技术的新型课堂则为解决这一问题提供了新的思路。VR技术和材料分析测试技术的结合,能以一种十分生动的方式为学生讲解抽象的课程内容,从而降低课程难度,增加互动体验,更加易于学生理解课程的内容。基于此,文章主要针对VR技术在材料分析测试技术课程中的应用展开论述。