Thermoacoustic imaging:From single-element scanning to portable and array-based imaging

The microwave-induced thermoacoustic imaging(TAI)technology has both the advantages of high contrast of microwave imaging and high resolution of ultrasound imaging(UI),so it has carried out exploratory application research in various areas,such as the early detection of breast tumors and cerebrovascular diseases.However,the microwave generator used in the traditional TAI technology is huge and expensive,and the temporal resolution is also too low due to the single-element scanning mechanism.Thus,it is difficult to meet the needs of clinical applications.In this paper,the iterative process and the analysis of related application scenarios from single-element scanning to portable and array-based TAI,such as the miniaturized microwave generator,handheld antenna,multi-channel data acquisition,and UI/TAIdual-modality imaging,are reviewed,and the future trends of this technology are discussed.This review helps researchers in the field of TAI learn the technological development process and future trends.It also deepens clinicians’understanding of TAI so as to put forward more application requirements.

ARM-Based Embedded System Platform and Its Portability Research

Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the schematic diagram as well as PCB, complete the hardware debugging, and ensure the system hardware platform function;in the software design, optimize the three-stage pipeline structure of ARM instruction system, design the instruction set, install the embedded system on the virtual machine, build the cross-toolchain, and set up the correct NFS network file system. Finish the design of the ARM-based embedded system platform, combined with the hardware requirements of the experimental platform, transplant the powerful Uboot as the Bootloader of the system, and further transplant the Linux-2.6. 32 kernel to the system start the operation normally, and finally, build the root file to finish the study of its portability.

In Search of Portable Water Supplies within a Brine and Mine Water-Invaded Region for Serving Some Communities around Ishiagu, Afikpo and Environs in Abakaliki Basin, Southeast Nigeria

The study investigates the hydrogeochemical characteristics of some towns in the Abakaliki Basin, comprising, Ishiagu, Aka Eze, Amaseri, Afikpo and Okposi communities, with the aim of sourcing for portable water in the area. The basin is underlain by Albian sediments, essentially shales, in the lowlands, which were affected by low-grade metamorphism that had produced slates. The highlands comprise basic intrusives from episodes of magmatism and metallic ore mineralisation. Injection of brines into the aquifer system and low, seasonal aquifer recharge from rainfall results in poor water quality in the area. The study analyzes the geochemical distribution in water sources in the area and identifies sources of pollutants to guide the better choice of portable water. Results of hydrogeochemical analysis of both surface and groundwater from the communities were compared with World Health Organization to identify portable water locations in the area. While the salt lake at Okposi is the main source of brine intrusion in the study area, the Pb/Zn mine at Ishiagu is the main source of mine-water pollution in the study area. Most chemical parameters, (especially Cl-, Na+, Ca2+, Mg2+, SO42-, HCO3-) maintain high concentrations within the salt lake area, with the values declining away from the salt lake. The main anthropogenic source of pollution in the area, especially at Ishiagu, is the indiscriminate surface mining of lead-zinc without proposer waste management practices. Possible sourcing for portable water in the study area includes a deep borehole at Ishiagu, away from lead-zinc intrusives. At the Okposi axis, searching for portable water in boreholes should target shallower aquifers that do not communicate with the deeper-seated brine zones, likewise targeting zones farther away from these brine-invaded areas. A controlled pumping rate could potentially ensure that the cone of depression was not low enough to reach the brine zone at depth. In addition, desalination could also potentially render the salt water drinkable if properly handled to eliminate the high concentration of salts in the water to the level of acceptable limit by the WHO. Based on the study, the best area to target for portable water in the study area is Afikpo, with most geochemical elements naturally occurring within WHO’s standard concentration while portable water could be harnessed in areas further away from mining sites, especially at deep groundwater.

Development of a portable reflectance confocal microscope and its application in the noninvasive in vivo evaluation of mesenchymal stem cell-promoted cutaneous wound healing

The process of wound healing is routinely evaluated by histological evaluation in the clinic,which may cause scarring and secondary injury.Reflectance confocal microscopy(RCM)represents a noninvasive,real-time imaging technique that allows in vivo evaluation of the skin.Traditional RCM was wide-probe-based,which limited its application on uneven and covered skin.In this study,we report the development of a portable reflectance confocal microscope(PRCM)in which all components were assembled in a handheld shell.Although the size and weight of the PRCM were reduced based on the use of a microelectromechanical system,the resolution was kept at 0.91μm,and the field of view of the system was 343μm×532μm.When used in vivo,the PRCM was able to visualize cellular and nuclear morphology for both mouse and human skin.PRCM evaluations were then performed on wounds after topically applied mesenchymal stem cells(MSCs)or saline treatment.The PRCM allowed visualization of the formation of collagen bundles,re-epithelization from the wound edge to the wound bed,and hair follicle regeneration,which were consistent with histological evaluations.Therefore,we offer new insights into monitoring the effects of topically applied MSCs on the process of wound healing by using PRCM.This study illustrates that the newly developed PRCM represents a promising device for real-time,noninvasive monitoring of the dynamic process of wound healing,which demonstrates its potential to diagnose,monitor,or predict disease in clinical wound therapy.

Portable FBAR based E-nose for cold chain real-time bananas shelf time detection

Being cheap,nondestructive,and easy to use,gas sensors play important roles in the food industry.However,most gas sensors are suitable more for laboratory-quality fast testing rather than for cold-chain continuous and cumulative testing.Also,an ideal electronic nose(E-nose)in a cold chain should be stable to its surroundings and remain highly accurate and portable.In this work,a portable film bulk acoustic resonator(FBAR)-based E-nose was built for real-time measurement of banana shelf time.The sensor chamber to contain the portable circuit of the E-nose is as small as a smartphone,and by introducing an air-tight FBAR as a reference,the E-nose can avoid most of the drift caused by surroundings.With the help of porous layer by layer(LBL)coating of the FBAR,the sensitivity of the E-nose is 5 ppm to ethylene and 0.5 ppm to isoamyl acetate and isoamyl butyrate,while the detection range is large enough to cover a relative humidity of 0.8.In this regard,the E-nose can easily discriminate between yellow bananas with green necks and entirely yellow bananas while allowing the bananas to maintain their biological activities in their normal storage state,thereby showing the possibility of real-time shelf time detection.This portable FBAR-based E-nose has a large testing scale,high sensitivity,good humidity tolerance,and low frequency drift to its surroundings,thereby meeting the needs of cold-chain usage.

Impact of Portable Executable Header Features on Malware Detection Accuracy

One aspect of cybersecurity,incorporates the study of Portable Executables(PE)files maleficence.Artificial Intelligence(AI)can be employed in such studies,since AI has the ability to discriminate benign from malicious files.In this study,an exclusive set of 29 features was collected from trusted implementations,this set was used as a baseline to analyze the presented work in this research.A Decision Tree(DT)and Neural Network Multi-Layer Perceptron(NN-MLPC)algorithms were utilized during this work.Both algorithms were chosen after testing a few diverse procedures.This work implements a method of subgrouping features to answer questions such as,which feature has a positive impact on accuracy when added?Is it possible to determine a reliable feature set to distinguish a malicious PE file from a benign one?when combining features,would it have any effect on malware detection accuracy in a PE file?Results obtained using the proposed method were improved and carried few observations.Generally,the obtained results had practical and numerical parts,for the practical part,the number of features and which features included are the main factors impacting the calculated accuracy,also,the combination of features is as crucial in these calculations.Numerical results included,finding accuracies with enhanced values,for example,NN_MLPC attained 0.979 and 0.98;for DT an accuracy of 0.9825 and 0.986 was attained.

便携式激光诱导击穿光谱仪测定土壤中重金属

土壤重金属污染对农作物生长和人体健康都有严重危害,现场快速检测对土壤重金属污染调查、应急监测具有重要意义。采用自主研发的土壤重金属激光诱导击穿光谱现场快速检测仪对矿区周边土壤进行现场检测分析,以835个不同基质土壤的光谱数据建立定标数据库,通过支持向量机建立回归模型对土壤重金属元素含量进行定量反演。现场检测获取的全波段光谱波动在15%以内,Cd、Cr、Cu、Ni、Pb和Zn等6种元素光谱强度相对标准偏差平均值为6.31%。将检测结果与实验室电感耦合等离子体质谱法分析对比,6种元素的皮尔逊相关系数r在0.8501~0.9829,检测结果80%以上处于±30%相对误差区间分布。对比结果表明自主研发的土壤重金属激光诱导击穿光谱现场检测仪可以满足现场快速检测需求。

基于便携式骨龄检测仪对杭嘉湖地区儿童及青少年骨龄调查研究

目的基于便携式骨龄检测仪对杭嘉湖地区儿童及青少年骨龄情况进行调查研究,为该地区的骨龄评估方法提供参考。方法回顾性收集1054名杭嘉湖地区3~18岁儿童及青少年的X线骨龄图像,并对骨龄图像进行骨龄判读,分析男性、女性的骨龄发育与生活年龄的差异及Greulich-Pyle图谱法(GP)、Tanner Whitehouse Ⅲ(TW3)计分法R系列(TW3-R)和C系列(TW3-C)两种以及《中国人手腕骨发育标准——中华05》法(中华05法)中的中华05-R系列、中华05-C系列5种骨龄评估方法的变化趋势,并对身高、BMI百分位数进行亚组分析。结果男性组≥3~<9岁年龄段及≥13~<18岁年龄段5种评估方法的骨龄结果差异均有统计学意义(均P<0.05)。≥9~<13岁年龄段间不同评估方法结果差异均无统计学意义(均P>0.05)。女性组从≥3~<5岁到≥13~<15岁的年龄段5种测评方法的结果差异均有统计学意义(均P<0.05)。5种骨龄评估方法所测骨龄与生活年龄的差值随年龄变化的趋势并无明显的性别差异。TW3-R系列在所有年龄段骨龄测量结果均比较接近实际生活年龄,中华05-C系列和TW3-C系列在中间层年龄段的骨龄测量结果更为准确。结论基于便携式骨龄检测仪的5种骨龄评价方法具有一定的准确度,但无法精确反映杭嘉湖地区儿童及青少年的骨骼发育实际情况,放射科医师需结合多种评估方式综合分析。

猕猴桃便携式无损检测仪影响因素及其精度校准分析

为探究产地、成熟度对便携式可溶性固形物无损检测精度的影响,以同一品种3个产地的猕猴桃为试材,分别采用便携式无损检测仪和常规有损检测仪对其可溶性固形物含量进行测定和比较,并运用人工神经网络对其进行分析。结果表明,在使用便携式无损检测仪对猕猴桃可溶性固形物检测时,3个产地的无损检测R2分别为0.26、0.52、0.61,成熟度会对其检测精度造成一定影响,但在不同产地间没有稳定、统一的规律;基于人工神经网络学习、建模产生的随机预测值可将R2提高5%~49%。因此,可利用预测值来作为中间校准程序,以辅助提高便携式无损检测精度。

一种可移动防止内瘘渗血监测装置的设计

针对透析患者在治疗过程中发生内瘘渗血问题,设计一种可移动的内瘘渗血监测装置,应用蓝牙技术设计电路图,建立内瘘渗血智能化报警模式,可实时提醒内瘘渗血。该装置应用吸湿棉贴及实时提醒装置等技术,对现有血透机的设计缺陷及相关处理方案予以补充,能够有效实现内瘘渗血的安全管理,避免因处理不及时所致的不良事件发生。

基于ETPP模式的单片机原理与接口技术课程实践教学改革探索

针对单片机原理与接口技术课程在传统实践教学过程中,学生受规定时间、固定地点、指定实验设备的限制,实践与创新热情不能充分发挥的问题,该文以学生发展为中心,以提高学生实践能力为核心,构建ETPP渐进式从理论到实践、从仿真到实操的新型实践教学模式,打造完整的实践教学生态和全过程综合考核评价体系。学生使用51系列、STC15系列、Arduino UNO R3和STM32四种单片机便携式实验装置和多种传感器及外设模块,随时随地学习并实践,激发主动学习和探索实践的热情。实践教学表明,ETPP模式能够更好地培养实践能力强、创新能力强、符合社会需求的复合型创新型新工科人才,具有良好的教学效果。

基于新型改进矩阵束的便携式电网同步相量测量装置

针对传统同步相量算法受电网间谐波影响较大的问题,本文提出了一种基于新型改进矩阵束的电网同步相量测量算法.将电网信号构建成Hankel矩阵,对其进行奇异值分解并使用自适应定阶方法滤除其中的噪声干扰分量,通过矩阵运算得到准确的电压幅值、频率及相角.经过仿真验证,本算法对含有间谐波分量的电网信号测量结果优于流行的傅里叶变换测量算法.并根据此算法设计了一款便携式电网同步相量测量装置,可解决传统同步相量测量设备体积庞大、成本较高的问题,利用高精度卫星同步信号监测晶振实际频率,动态调整采样控制参数降低采样时间误差,将同步采样的电网波形参数与时间标签等无线传输至移动终端,完成电网信号幅值、频率及相角计算.实际测试表明,本装置具有较高的测量精度,其中电压幅值、频率和相角测量误差分别为0.038 5%、0.000 51 Hz和0.053 7°,满足《电力系统同步相量测量装置检测规范》(GB/T 26862—2011),具有较强的实际应用价值.

一种便携式机械设计工具箱的设计

随着社会的发展和智能制造技术的进步,无论是企业还是生产工人,对机械设计工具箱的要求越来越高。机械设计工具箱广泛地应用于机电类、机械类、汽车类、建筑类等专业中。针对目前机械设计工具箱结构简单、功能单一、工具难以找寻、容易发生碰撞导致损伤等缺点,本文将箱体、箱盖、滑轮、折叠支撑柱、拉杆、阻隔板、防水工具袋、电源、固定块、显示屏、缠绕柱、手提把等连接在一起,设计出一种新型的便携式机械设计工具箱,保证了机械设计工具的方便拿取,便于携带,提高了工作效率,极大地满足了企业和员工的需求,适合大批量生产、推广和应用。

便携式锂钾分析仪现场测定热泉水中的锂

锂是绿色能源和轻质合金的理想原料,作为一种重要的战略性资源而备受各国重视。热泉水中富含锂,储量可观,然而热泉水主要分布在西藏、云南等偏远地区,样品运输与实验室测试成本高、效率低,锂资源勘查急需现场分析技术的支持。热泉水一般含有较高浓度的钠、钾等元素,基体效应显著。本文利用自主研发的便携式锂钾分析仪,搭配负性滤光片,选择锂的分析谱线波长670.78nm,通过优化测量条件,建立了标准曲线法与标准加入法现场测定热泉水中锂元素的分析方法。实验结果表明,当电解质是体积分数为1.5%的盐酸,工作电流为70mA,进样流速为3.0mL/min时,锂检出限为4.07μg/L,相对标准偏差(RSD)为1.03%。对热泉水样品进行加标测试,加标回收率为81.6%~115.9%。当热泉水样品基体组成较简单时,直接采用标准曲线法即可获得较准确的分析结果;当样品基体组成较复杂或者基体浓度高时,采用标准加入法可有效地减小基体效应,获得的分析结果相对更准确。本方法适用于不同类型基体的热泉水中锂含量的分析测试。

基于虚拟现实全视野刺激下便携式眼震视图仪所测视动性眼震参数的可信度研究

目的探究便携式眼震视图仪基于虚拟现实全视野刺激下测得的视动性眼震(optokinetic nystagmus,OKN)参数的可信度。方法单纯随机选取2022年7月—2023年6月兰州大学第二医院纳入的60例健康受试者为研究对象,按照随机数表法分为两组,每组30例,对照组采用传统全视野刺激眼震视图仪,观察组采用便携式虚拟现实全视野刺激眼震视图仪,对比两组设备的OKN参数数值。结果观察组左眼眼震次数、慢相速度、快相速度、慢相时间、快相时间、增益、慢相速度/快相速度、慢相时间/快相时间为(21.26±4.26)次、(51.23±4.45)°/s、(304.52±12.26)°/s、(280.52±24.26)ms、(50.52±12.26)ms、0.74±0.26、0.18±0.04、6.05±1.26,与对照组对比,差异无统计学意义(t=0.332、0.196、0.545、0.479、0.019、0.310、0.968、0.186,P均>0.05)。两组自发性眼动试验结果对比,差异无统计学意义(P>0.05)。结论虚拟现实全视野刺激下便携式眼震视图仪用于测定OKN参数的可信度较高,与传统全视野刺激眼震视图仪所测得的OKN参数比值差异较小,并且二者所测得的自发性眼震试验结果亦无明显差异,表明便携式眼震视图仪在眼震检查方面具有较高的准确性。

平台工人数据可携带权:法理证成与制度构建

平台企业在用工过程中强化了对平台工人的数据收集与算法管理,平台工人的数据权利保护亟待提上日程。数据可携带权已经得到欧盟立法的确认,在我国,进一步明确平台工人的数据可携带权存在必要性,该权利的设立不仅有利于维护平台工人的人格利益、财产利益,还有利于保障其择业自由。然而,该制度的设立存在诸多难点,平台工人数据可携带权的适用对象的模糊可能导致数据权属争议,数据存储转移格式不统一将引发监管困难,还存在限制平台用工市场竞争的风险。宜从平台用工中不同主体义务的立法设置、平台工人数据可携带权的适用对象和数据存储转移标准三条进路,构建平台工人数据可携带权的制度,以充分保障平台工人的数据权利。

异地就医直接结算、待遇可携带性与人口流动适应性研究

在人口大规模流动常态化的社会背景下,异地就医直接结算作为提升医保公共服务效能的政策创新,满足流动人口就医需求的同时也充当着适应人口流动的重要保障机制。本文选取中国健康与养老追踪调查数据,采用Logit模型、PSM模型及中介效应模型对我国异地就医直接结算的人口流动适应性及作用机制进行实证评估。研究发现,随着医保异地就医直接结算开展范围的扩大,一定程度上打破了传统医保的“枷锁”效应,更加适应人口流动。机制分析表明,异地就医直接结算政策通过增强医保待遇可携带性适应人口流动,具体表现为减轻异地就医人员的间接医疗成本、缩短其异地往返的通勤距离和减少垫资成本。医保异地就医直接结算对健康状况好、45岁以下及60岁以上、工作类型为个体或私营、收入较高者等群体的流动具有更好的适应效果。

基于动态阈值分割法的接触轨图像关键特征点提取方法研究

在地铁系统中,接触轨的状态对于牵引供电系统的安全性至关重要,一旦接触轨几何参数超出正常范围,不仅会导致集电靴无法正常取流,进而影响运营车辆的顺畅运行,而且在极端情况下,还可能引发严重的安全事故。传统的接触轨几何参数测量方法在采集图像时通常面临背景复杂、干扰图像多等问题,以致检测数据量少、检测密度低,从而难以精确提取接触轨的关键特征信息。针对这一问题,文章提出一种新的方法,即结合动态阈值分割法、直线拟合以及投影计算的方式,有效解决接触轨特征点提取的难点,实现几何参数的精确测量。该方法不仅能够准确捕捉到接触轨的细微变化,还能够确保测量结果的可靠性和准确性。为进一步提高测量的便捷性和实用性,研究过程中同步研制出一套接触轨几何参数的便携式测量装置,并在地铁线路上进行现场应用示范,为实际运营中的接触轨状态监测提供有力的技术支持。

手持式近红外光谱仪测定梨三种品质指标通用模型建模方法研究

梨是生活中非常常见的水果,梨的糖度、酸度(pH)、硬度是评价梨品质的重要指标。近红外光谱技术因快速、无损和高效等优点,广泛应用于检测水果品质指标。手持式近红外光谱仪可以应用于现场无损检测梨品质,梨的大小不同会对梨的光谱和建模产生一定影响。因此,采集大小不同的5个品种梨果(雪梨、红香酥、蜜梨、红肖梨、酸梨)的近红外光谱,最大的雪梨平均赤道周长27.64 cm,重量为362.84 g,最小的蜜梨平均赤道周长18.35 cm,重量为112.67 g,共197个样品。光谱范围为900~1700 cm^(-1),并在梨的赤道上选取三个点测量梨果的可溶性固形物、酸度(pH)与硬度三个化学指标。采集光谱发现,小梨吸光度较大,而大梨吸光度较小。采用三点平均光谱代表样品光谱和一阶导预处理,改善了光谱的一致性,解决了样品不均匀性、不同梨大小不同等因素的影响。线性回归模型PLS可溶性固形物、酸度(pH)和硬度的校正集决定系数依次为0.7394、0.9335、0.8866,预测集决定系数依次为0.7559、0.8734、0.7874,校正集RMSEC依次为0.5504、0.1941、0.5181。预测集RMSEP依次为0.6564、0.2420、0.6692。非线性回归LSSVM模型可溶性固形物、酸度(pH)和硬度的校正集决定系数依次为0.9763、0.9999、0.9960,预测集决定系数依次为0.9234、0.9777、0.9394,校正集RMSEC依次为0.1949、0.0033、0.0894。预测集RMSEP依次为0.3169、0.1089、0.3613。对比线性算法和非线性算法,LS-SVM建模效果明显优于PLS,LS-SVM算法适用于更多的品种、更宽的品质指标范围的样品预测,模型的准确度和稳定性有了显著提高,可以建立不同品种大小的梨的通用模型。手持式近红外光谱仪可用于梨果的糖度、硬度和pH值的快速无损高效检测,并摆脱了实验室的限制,可以实现现场快速检测。

便携式土壤土霉素提取-检测装置设计与试验

土壤中土霉素(Oxytetracycline,OTC)高性能的现场分析方法对于保护生态环境安全和维护人类健康具有重要意义。针对土壤中痕量OTC的现场检测难题,设计功能集成的便携式提取-检测装置,用于土壤中OTC的现场提取与精准分析。首先,基于集成电路技术与3D建模,研制具有称量、搅拌与离心功能的便携式装置,并通过与实验室用提取装置的性能对比,验证装置的提取精度;分别以LED和便携式电化学工作站为光电化学检测的光源驱动和信号采集装置,研制便携式检测装置;进行土壤中OTC的现场分析试验。结果表明,研制的便携式装置对土壤OTC的提取精度较高,检测的线性范围为1×10^(-8)~1×10^(-6) mol/L,检出限为5.33×10^(-9) mol/L;在现场分析试验中,对土壤中OTC检测的加标回收率为92%~97%,相对标准偏差为1.8%~5.2%,且准确度得到了国标法的验证。