期刊文献+
共找到408,860篇文章
< 1 2 250 >
每页显示 20 50 100
基于改进RT-DETR的有遮挡交通标志检测算法
1
作者 于天河 杨壮壮 +2 位作者 胡金帅 常梦瑶 王文龙 《工程科学学报》 北大核心 2026年第2期393-408,共16页
针对交通标志检测中目标尺寸小、检测精度低等问题,尤其是在远距离拍摄、遮挡严重的情况下,传统检测算法往往难以准确识别交通标志.本文提出了一种基于改进RT-DETR的交通标志检测算法.首先,考虑到当前交通标志被遮挡情况下数据集的匮乏... 针对交通标志检测中目标尺寸小、检测精度低等问题,尤其是在远距离拍摄、遮挡严重的情况下,传统检测算法往往难以准确识别交通标志.本文提出了一种基于改进RT-DETR的交通标志检测算法.首先,考虑到当前交通标志被遮挡情况下数据集的匮乏,自建一个遮挡条件下的交通标志数据集.然后,在反向残差移动块中引入膨胀重参数块,构建了一个轻量级的复合膨胀残差块来替换原始主干提取网络中的BasicBlock,增强了模型的特征提取能力.最后,对RT-DETR模型的损失函数进行了优化,提出了DS-IoU联合损失函数加快收模型敛速度.实验结果表明,改进后的算法在自制数据集上的m AP为94.2%,相比于原始算法增加量为4.7%,在公开数据集TT100K和CCTSDB2021的m AP分别为92.8%和91.7%,相比于原始算法增加量分别为3.1%和2.4%,Params和GFLOPs相比于原始的算法分别降低了26.0%和12.5%.本文提出的改进方法极大地减少了计算量和参数数量,有效提升了遮挡情况下的交通标志的检测精度. 展开更多
关键词 交通标志检测 rt-DETR 遮挡数据集 轻量化 联合损失函数
在线阅读 下载PDF
基于RT-GLV的变电站电力人员绝缘手套穿戴检测方法
2
作者 袁杰 万忠原 +3 位作者 加尔肯别克 杨怡程 祁鹏程 陈治润 《郑州大学学报(工学版)》 北大核心 2026年第1期25-32,共8页
变电站电力人员作业穿戴的绝缘手套有目标小、易遮挡的特点,而一般的特征融合网络往往会丢失小目标信息。针对此问题,构建一种多尺度小目标特征融合网络STPFM,对RT-DETR-R18模型进行改进,设计了电力人员绝缘手套穿戴模型RT-GLV。首先,用... 变电站电力人员作业穿戴的绝缘手套有目标小、易遮挡的特点,而一般的特征融合网络往往会丢失小目标信息。针对此问题,构建一种多尺度小目标特征融合网络STPFM,对RT-DETR-R18模型进行改进,设计了电力人员绝缘手套穿戴模型RT-GLV。首先,用STPFM网络代替CCFM网络,利用STPFM网络的SSFF模块、TFE模块融合多尺度特征信息,此外,增加一个以SSFF模块为核心的小目标检测层,增强模型对小目标信息的学习能力;其次,为解决替换的STPFM网络模型参数量过大的问题,构建一种轻量化PB_Block模块,只替换主干网络中包含小目标信息较少的P4、P5层的模块,在轻量化模型的同时,又降低小目标信息的损失;最后,采用PIoUv2损失函数增强模型对难易样本的学习能力。实验结果表明:RT-GLV模型在电力人员绝缘手套穿戴检测中表现优异,与RT-DETR-R18相比,mAP@0.5提高2.1百分点,F 1分数提高1.6百分点,参数量减少21.5%;在小目标检测方面,穿戴绝缘手套的AP@0.5提高1.4百分点,未穿戴绝缘手套的AP@0.5提高6.4百分点,且模型检测速度达到91.3帧/s,满足电力人员绝缘手套穿戴检测的准确性、实时性要求。 展开更多
关键词 绝缘手套 rt-DETR 多尺度融合 轻量化 Powerful-IoU
在线阅读 下载PDF
Field Testing Methodology for Wave Energy Converters Using the MIKE 21 Model 被引量:1
3
作者 Ning Jia Xiangnan Wang +1 位作者 Linsheng Han Hainan Xia 《Energy Engineering》 2025年第6期2389-2400,共12页
With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist i... With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter. 展开更多
关键词 Wave energy converter site testing MIKE21 SW model
在线阅读 下载PDF
Kali Pi—A Miniature Ultra-Portable Penetration Testing Device
4
作者 Ahmed Bin Ali 《Journal of Information Security》 2025年第1期101-113,共13页
Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant... Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant on traditional laptops and computers, which, while portable, lack true ultra-portability. This paper explores the potential impact of developing a dedicated, ultra-portable, low-cost device for on-the-go penetration testing. Such a device could replicate the core functionalities of advanced penetration testing tools, including those found in Kali Linux, within a compact form factor that fits easily into a pocket. By offering the convenience and portability akin to a smartphone, this innovative device could redefine the way penetration testers operate, enabling them to carry essential tools wherever they go and ensuring they are always prepared to conduct security assessments efficiently. This approach aims to revolutionize penetration testing by merging high functionality with unparalleled portability. 展开更多
关键词 Penetration testing Portable Device CYBERSECURITY Raspberry Pi
在线阅读 下载PDF
On uncertainty of elastic modulus measurements via nanoindentation mechanical testing and conventional triaxial testing
5
作者 Zhidi Wu Eric Edelman +2 位作者 Kathleen Ritterbush Yanbo Wang Brian McPherson 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4700-4714,共15页
Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are ... Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are attractive at different scales.Each method requires minimal sample volume,is low cost,and includes a relatively rapid measurement turnaround time.However,recent micro-scale test results–including scratch test results and nanoindentation results–exhibit tangible variance and uncertainty,suggesting a need to correlate mineral composition mapping to elastic modulus mapping to isolate the relative impact of specific minerals.Different research labs often utilize different interpretation methods,and it is clear that future micro-mechanical tests may benefit from standardized testing and interpretation procedures.The objectives of this study are to seek options for standardized testing and interpretation procedures,through two specific objectives:(1)Quantify chemical and physical controls on micro-mechanical properties and(2)Quantify the source of uncertainties associated with nanoindentation measurements.To reach these goals,we conducted mechanical tests on three different scales:triaxial compression tests,scratch tests,and nanoindentation tests.We found that mineral phase weight percentage is highly correlated with nanoindentation elastic modulus distribution.Finally,we conclude that nanoindentation testing is a mineralogy and microstructure-based method and generally yields significant uncertainty and overestimation.The uncertainty of the testing method is largely associated with not mapping pore space a priori.Lastly,the uncertainty can be reduced by combining phase mapping and modulus mapping with substantial and random data sampling. 展开更多
关键词 Elastic modulus Nanoindentation test Triaxial test Scratch test Uncertainty source Uncertainty quantification Pore space
在线阅读 下载PDF
Human immunodeficiency virus recency testing coverage and partner-notification-services among people-living with human immunodeficiency virus in low- and middle-income countries
6
作者 Ibrahim Ahmed El-Imam Timothy Antipas Peter +7 位作者 Hassan Fredrick Fussi Zuhura Mbwana Ally Hafidha Mhando Bakari Mariam Salim Mbwana Upendo Kayeke Chenya Beatrice Kelvin Mpimo Haji Mbwana Ally Habib Omari Ramadhani 《World Journal of Virology》 2025年第4期112-125,共14页
BACKGROUND Human immunodeficiency virus(HIV)recency testing provides data that can be used to monitor the trend of new HIV infections.The effectiveness of using people identified with recent infection to identify part... BACKGROUND Human immunodeficiency virus(HIV)recency testing provides data that can be used to monitor the trend of new HIV infections.The effectiveness of using people identified with recent infection to identify partners with new HIV infection through partner notification services(PNS)is not well documented.AIM To determine the pooled prevalence of recency testing coverage,recent infection,reclassification(recent to longterm infection)and PNS cascade among newly diagnosed people living with HIV.METHODS PubMed,Cochrane Library and Embase were searched for articles published between January 2018 and November 2024.Studies were included if they reported recency coverage and/or PNS among people newly diagnosed with HIV and used recent infection testing algorithm(RITA).Recency coverage was defined as proportion of people tested using rapid testing for recent infection(RTRI)among those newly diagnosed with HIV.RITA further classifies RTRI results using viral load results(≥1000 copies/mL vs<1000 copies/mL)to confirm recency status.For studies with PNS,we evaluated the cascade:Number of partners elicited,successfully contacted,eligible for HIV testing,tested and HIV diagnosis.PNS effectiveness was measured by proportion of new HIV diagnoses from tested partners.Using random effects models,we computed the pooled estimate of recency outcomes and 95%confidence intervals(CIs).RESULTS Twenty-five studies from 17-low-and middle-income countries were included.Of 276315 newly diagnosed people living with HIV,79864 underwent RTRI with an overall pooled recency coverage of 87%(95%CI:67-96).The pooled prevalence of RTRI and RITA recency were 12%(95%CI:9-16)and 7%(95%CI:4-10),respectively.Pooled prevalence of RTRI reclassification was 34%(95%CI:22-49).Of the recent cases who agreed to PNS,253 partners were elicited with an estimated elicitation ratio of 1:1.6.Among partners elicited,99%were successfully contacted,75%were eligible for testing,68%tested for HIV,and 15%were diagnosed with HIV.CONCLUSION High recency testing coverage among newly diagnosed individuals demonstrates the feasibility of monitoring new HIV infections in LMIC.While PNS yielded moderate HIV diagnoses,its targeted approach remains a critical strategy for identifying undiagnosed cases. 展开更多
关键词 Human immunodeficiency virus recency testing coverage Rapid test for recent infection Recent infection testing algorithm Partner notification services MISCLASSIFICATION Recent infection surveillance Low-and mid-income countries
暂未订购
Development of a smartphone-integrated handheld automated biochemical analyzer for point-of-care testing of urinary albumin
7
作者 Ze Wu Peng Zhang +7 位作者 Wei Xiao Qian Chen Wangrun Lin Peipei Chen Kangwei Chen Qiangqiang Fu Zhijian Wang Lei Zheng 《Journal of Pharmaceutical Analysis》 2025年第3期577-584,共8页
The level of urinary albumin is a critical indicator for the early diagnosis and management of chronic kidney disease(CKD).However,existing methods for detecting albumin are not conducive to point-of-care testing due ... The level of urinary albumin is a critical indicator for the early diagnosis and management of chronic kidney disease(CKD).However,existing methods for detecting albumin are not conducive to point-of-care testing due to the complexity of reagent addition and incubation processes.This study presents a smartphone-integrated handheld automated biochemical analyzer(sHABA)designed for point-of-care testing of urinary albumin.The sHABA features a pre-loaded,disposable reagent cassette with reagents for the albumin assay arranged in the order of their addition within a hose.The smartphone-integrated analyzer can drive the reagents following a preset program,to enable automatic sequential addition.The sHABA has a detection limit for albumin of 5.9 mg/L and a linear detection range from 7 to 450 mg/L.The consistency of albumin level detection in 931 urine samples using sHABA with clinical tests indicates good sensitivity(95.78%)and specificity(90.16%).This research advances the field by providing an automated detection method for albumin in a portable device,allowing even untrained individuals to monitor CKD in real time at the patient's bedside.In the context of promoting tiered diagnosis and treatment,the sHABA has the potential to become an essential tool for the early diagnosis and comprehensive management of CKD and other chronic conditions. 展开更多
关键词 Chronic kidney disease ALBUMIN SMArtPHONE Biochemical analyzer Point-of-care testing
暂未订购
Exercise-Induced Syncope During Treadmill Testing in a Sedentary Woman:A Case Report
8
作者 Yu Zhang¹ Jian Huang 《Journal of Clinical and Nursing Research》 2025年第9期42-46,共5页
Vasovagal syncope(VVS),which is triggered by physical exertion,is typically observed in athletes or patients with structural heart disease.There have been few reported cases among sedentary individuals.This case repor... Vasovagal syncope(VVS),which is triggered by physical exertion,is typically observed in athletes or patients with structural heart disease.There have been few reported cases among sedentary individuals.This case report details the experience of a 42-year-old sedentary woman who fainted during a treadmill stress test.Despite the absence of abnormalities in baseline cardiac and neurological evaluations,the patient exhibited sinus arrest(lasting 5–12 seconds)with significant ST-segment depression during haemodynamic collapse.Comprehensive assessments,incorporating coronary angiography,echocardiography,cranial computed tomography(CT),and biochemical testing,excluded the presence of structural or ischemic heart disease,arrhythmogenic syndromes,and cerebrovascular disorders.A Calgary Syncope Symptom Score of 3 confirmed the diagnosis of VVS,a diagnosis that was further substantiated by the patient’s symptoms resolving spontaneously when she was positioned supine.This case demonstrates that exercise-induced syncope can occur in individuals who are physically unfit and have no cardiac abnormalities.Transient ST-segment changes in such cases reflect autonomic nervous system dysfunction rather than myocardial ischaemia.It is incumbent upon clinicians to consider a neurocardiogenic mechanism in sedentary patients presenting with exertional syncope despite a negative standard cardiac evaluation. 展开更多
关键词 Vasovagal syncope Exercise test Sedentary behavior ST segment depression Sinus arrest
暂未订购
Construction of a Virtual Twin Testing Framework for Safety of the Intended Functionality in Intelligent Connected Vehicles
9
作者 Quanyou Fu Daxu Sun 《Journal of Electronic Research and Application》 2025年第5期12-17,共6页
This study aims to construct a virtual twin testing framework for the safety of the intended functionality of intelligent connected vehicles to address the safety requirements of intelligent driving and transportation... This study aims to construct a virtual twin testing framework for the safety of the intended functionality of intelligent connected vehicles to address the safety requirements of intelligent driving and transportation systems.The research methods include the construction of a theoretical model of safety for intelligent connected vehicles based on the concept of virtual twins,the correlation study between key concepts and functional safety,and the application research of virtual twin technology in the safety testing of intelligent connected vehicles.The results reveal that the virtual twin testing framework can effectively enhance the functional safety of intelligent connected vehicles,reduce development costs,and shorten the product launch cycle.The conclusion suggests that this framework provides strong support for the healthy development of the intelligent connected vehicle industry and has a positive impact on the safety and efficiency of intelligent transportation systems. 展开更多
关键词 Intelligent connected vehicles Safety of the intended functionality Virtual twin testing framework Safety theory model
在线阅读 下载PDF
Preventing transmission of dyschromatosis universalis hereditaria through preimplantation genetic testing:A case report
10
作者 Xue-Lian Wang Tong Zou +3 位作者 Yi-Cheng Wu You-Yi Weng Qiang Yao Wei-Wei Sun 《World Journal of Clinical Cases》 2025年第31期88-92,共5页
BACKGROUND Dyschromatosis universalis hereditaria(DUH)is a rare type of autosomal dominant inheritance disease.It has varying gene mutation sites among different ethnicities.SASH1 and ABCB6 have been identified as the... BACKGROUND Dyschromatosis universalis hereditaria(DUH)is a rare type of autosomal dominant inheritance disease.It has varying gene mutation sites among different ethnicities.SASH1 and ABCB6 have been identified as the causative genes of this disorder.CASE SUMMARY A 30-year-old woman presented with irregular black pigmentation spots to our department.Upon examination,the pigmentations were found to be especially dense on the extremities and the face.She had no family history of inbreeding,nor any previous chemical exposure.Genetic testing confirmed that the disease occu-rred because the patient has a SASH1 gene mutation.Following the use of assisted reproductive technology and preimplantation genetic testing for monogenic disorders,the patient give birth to a health baby.CONCLUSION Using assisted reproductive technology/preimplantation genetic testing for monogenic disorders is an option for DUH patients to reduce the risk of trans-mitting the pathogenic variant to their offspring. 展开更多
关键词 Dyschromatosis universalis hereditaria SASH1 PIGMENTATION Assisted reproductive technology Preimplantation genetic testing Monogenic gene diseases Case report
暂未订购
Thirteen serum biochemical indexes and five whole blood coagulation indices in a point-of-care testing analyzer:ideal protocol for evaluating pulmonary and critical care medicine
11
作者 Mingtao LIU Li LIU +7 位作者 Jiaxi CHEN Zhifeng HUANG Huiqing ZHU Shengxuan LIN Weitian QI Zhangkai J.CHENG Ning LI Baoqing SUN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 2025年第2期158-171,共14页
The accurate and timely detection of biochemical coagulation indicators is pivotal in pulmonary and critical care medicine.Despite their reliability,traditional laboratories often lag in terms of rapid diagnosis.Point... The accurate and timely detection of biochemical coagulation indicators is pivotal in pulmonary and critical care medicine.Despite their reliability,traditional laboratories often lag in terms of rapid diagnosis.Point-of-care testing(POCT)has emerged as a promising alternative,which is awaiting rigorous validation.We assessed 226 samples from patients at the First Affiliated Hospital of Guangzhou Medical University using a Beckman Coulter AU5821 and a PUSHKANG POCT Biochemistry Analyzer MS100.Furthermore,350 samples were evaluated with a Stago coagulation analyzer STAR MAX and a PUSHKANG POCT Coagulation Analyzer MC100.Metrics included thirteen biochemical indexes,such as albumin,and five coagulation indices,such as prothrombin time.Comparisons were drawn against the PUSHKANG POCT analyzer.Bland-Altman plots(MS100:0.8206-0.9995;MC100:0.8318-0.9911)evinced significant consistency between methodologies.Spearman correlation pinpointed a potent linear association between conventional devices and the PUSHKANG POCT analyzer,further underscored by a robust correlation coefficient(MS100:0.713-0.949;MC100:0.593-0.950).The PUSHKANG POCT was validated as a dependable tool for serum and whole blood biochemical and coagulation diagnostics.This emphasizes its prospective clinical efficacy,offering clinicians a swift diagnostic tool and heralding a new era of enhanced patient care outcomes. 展开更多
关键词 Thirteen serum biochemical indexes Five whole blood coagulation indices Point-of-care testing(POCT) Pulmonary and critical care medicine Diagnostic protocol
原文传递
Key role of Levitt’s carbon monoxide breath test in revealing coexistent Gilbert syndrome and erythropoietic protoporphyria:A case report
12
作者 Ling-Ling Kang Hou-De Zhang 《World Journal of Clinical Cases》 2026年第1期28-33,共6页
It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and er... It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and erythropoietic protoporphyria(EPP),which has not been previously documented.CASE SUMMARY We present a rare case of coexisting GS and EPP in a 23-year-old Chinese male with a long history of jaundice and recently found splenomegaly.Serial nonspecific hemolysis screening tests yielded inconsistent results,and investigations for common hemolytic etiologies were negative.However,Levitt’s carbon monoxide breath test,which measures erythrocyte lifespan(the gold-standard marker of hemolysis),demonstrated significant hemolysis,revealing a markedly shortened erythrocyte lifespan of 11 days(normal average 120 days).Genetic testing subsequently confirmed EPP with a homozygous ferrochelatase gene mutation and GS with a heterozygous uridine diphosphate glucuronosyl trans-ferase 1A1 gene mutation.CONCLUSION The rapid,non-invasive Levitt’s carbon monoxide breath test resolved the diagnostic challenge posed by a rare and complex cause of hyperbilirubinemia. 展开更多
关键词 Isolated hyperbilirubinemia Erythropoietic protoporphyria Gilbert syndrome HEMOLYSIS Levitt’s carbon monoxide breath test Erythrocyte lifespan Case report
暂未订购
低渗透介质热示踪传热过程的ERT动态监测方法研究
13
作者 赵永胜 王锦国 +2 位作者 乔斐 刘芮彤 陈舟 《地学前缘》 北大核心 2026年第1期523-533,共11页
热示踪技术作为获取多孔介质渗透特性与热力学参数的重要手段,在水文地质领域应用十分广泛。然而,传统热示踪方法严重依赖监测井内的点尺度温度探头数据,难以重构多孔介质传热过程的空间结构。针对传统热示踪试验点尺度温度探头数据在... 热示踪技术作为获取多孔介质渗透特性与热力学参数的重要手段,在水文地质领域应用十分广泛。然而,传统热示踪方法严重依赖监测井内的点尺度温度探头数据,难以重构多孔介质传热过程的空间结构。针对传统热示踪试验点尺度温度探头数据在传热过程刻画时的空间分辨率不足问题,本文在低渗透介质热示踪试验中引入高密度电阻率法(electrical resistivity tomography,ERT)。通过开展热示踪与高密度电阻率法联合监测,探究ERT在低渗透介质热示踪试验过程中提高传热过程监测空间分辨率方面的效果。此外,本文建立了黏土地层电阻率温度的定量反演方法。通过数值模拟正演验证了该方法的可靠性,并对影响可靠性的因素进行了分析。研究结果表明:由ERT监测得到的电阻率反演温度数据在以传热过程为主导的区域(监测井位置),与地下水温度变化趋势与幅度具有一致性;在以局部热对流为主导的区域(注水井位置),与地下水温度变化趋势一致,证实了ERT在弱透水层传热过程监测的可靠性。同时,通过ERT成功识别出优势通道或热敏感区,证实其对地下非均质性具有高度敏感性,能够显著提升热示踪试验传热过程的空间分辨率。本文构建的电阻率温度反演方法为低渗透介质热示踪提供了新方法,证实了ERT技术能够弥补传统热示踪试验传热过程空间分辨率不足的问题。 展开更多
关键词 高密度电阻率法 低渗透介质 热示踪试验 黏土电阻率温度关系 空间分辨率
在线阅读 下载PDF
Optimization and Testing for PCR System of Rice by Orthogonal Design 被引量:8
14
作者 程芳艳 李春光 +5 位作者 刘永巍 孟巧霞 张景龙 宋冬明 刘华招 孟昭河 《Agricultural Science & Technology》 CAS 2010年第2期61-64,共4页
[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves ... [Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves by CTAB method as the template,PCR system was optimized by L16(45)orthogonal design.[Result] Clear bands were amplified from 16 different combinations,but the amplification effects and yields had difference.The most economic and applicable system was as follows:20 ng DNA template,150 μmol/L dNT... 展开更多
关键词 RICE PCR system optimization Orthogonal design Dominant molecular markers testing
在线阅读 下载PDF
Seismic performance of double- skin steel- concrete composite box piers: Part Ⅰ——Bidirectional quasi-static testing 被引量:7
15
作者 夏坚 宗周红 +1 位作者 徐焯然 李明鸿 《Journal of Southeast University(English Edition)》 EI CAS 2016年第1期58-66,共9页
To study the seismic performance of double-skin steelconcrete composite box( DSCB) piers, a total of 11 DSCB pier specimens were tested under bidirectional cyclic loading. The effects of the loading pattern, the ste... To study the seismic performance of double-skin steelconcrete composite box( DSCB) piers, a total of 11 DSCB pier specimens were tested under bidirectional cyclic loading. The effects of the loading pattern, the steel plate thickness, the axial load ratio, the slenderness ratio and the aspect ratio were taken into consideration. The damage evolution process and failure modes of the tested specimens are presented in detail. Test results are also discussed in terms of the hysteretic curve, skeleton curve, ductility and energy dissipation capacity of DSCB pier specimens. It can be concluded that the hysteretic performance of DSCB piers in one direction is affected and weakened by the cyclic loading in the other direction. DSCB piers under bidirectional cyclic loading exhibit good performance in terms of load carrying capacity, ductility, and energy dissipation capacity. Overall, DSCB piers can meet the basic aseismic requirements. The research results can be taken as a reference for using DSCB piers as high piers in bridges in strong earthquakeprone areas. 展开更多
关键词 double-skin steel-concrete composite box(DSCB) pier bidirectional quasi-static testing hysteretic curve skeleton curve ductility energy dissipation capacity
在线阅读 下载PDF
Importance of Proficiency Testing in Water Quality Monitoring 被引量:2
16
作者 郭正 向哲涛 宋华力 《Agricultural Science & Technology》 CAS 2014年第12期2201-2203,共3页
The monitoring data is undoubtedly important to the water quality monitor- ing department. The proficiency testing is an important way to improve the monitor- ing capacity and enhance the quality management of laborat... The monitoring data is undoubtedly important to the water quality monitor- ing department. The proficiency testing is an important way to improve the monitor- ing capacity and enhance the quality management of laboratories. It plays an impor- tant role in ensuring the accuracy, integrity and comparability of monitoring data. In this paper, the positive role of proficiency testing in the water quality monitoring was analyzed. In addition, how to improve the water quality monitoring capacity and the quality management level of laboratories through the proficiency testing was also discussed. 展开更多
关键词 Proficiency testing Water quality monitoring Management level
在线阅读 下载PDF
鹅星状病毒通用型TaqMan探针实时荧光定量RT-PCR检测方法的建立与应用 被引量:1
17
作者 陈立功 穆英丽 +5 位作者 张诚 潘保革 范乐乐 魏忠华 王学静 刘聚祥 《中国家禽》 北大核心 2025年第2期53-59,共7页
为建立用于鹅星状病毒1(GAstV 1)和鹅星状病毒2(GAstV 2)感染快速检测的实时荧光定量RT-PCR方法,试验根据部分GAstV ORF2基因和部分3′非编码区序列设计合成特异性引物和探针,采用矩阵法获得引物和探针的最优浓度,在优化退火温度的基础... 为建立用于鹅星状病毒1(GAstV 1)和鹅星状病毒2(GAstV 2)感染快速检测的实时荧光定量RT-PCR方法,试验根据部分GAstV ORF2基因和部分3′非编码区序列设计合成特异性引物和探针,采用矩阵法获得引物和探针的最优浓度,在优化退火温度的基础上,分别建立扩增GAstV 1和GAstV 2的标准曲线,进一步验证该方法的特异性、敏感性和重复性,建立的方法用于临床样品的检测,并与文献报道的常规RT-PCR方法进行比较。结果显示:优化后的反应体系中最优上、下游引物浓度均为0.40(或0.50)μmol/L,探针浓度均为0.50μmol/L,扩增线性范围分别为3.26×10^(3)~3.26×10^(8)拷贝/μL和7.09×10^(3)~7.09×10^(8)拷贝/μL,相关系数均为0.998;该方法可特异性检出两种GAstV,但对新城疫病毒、H9亚型禽流感病毒、鸭坦布苏病毒、新型鸭呼肠孤病毒、鹅细小病毒和血清4型禽腺病毒6种鹅病相关病毒的核酸均无扩增信号;其检测限分别为3.26×10^(2)拷贝/μL和7.09×10^(1)拷贝/μL;组内变异系数和组间变异系数均低于3%。建立的实时荧光定量RT-PCR方法对临床样品的检测结果显示,GAstV阳性率为90.57%(96/106);而文献报道的常规RT-PCR方法对GAstV 1和GAstV 2的混合阳性率为62.26%。研究表明,建立的TaqMan荧光定量RT-PCR检测方法为同时检测GAstV 1和GAstV 2提供了快速、敏感、特异且能满足临床样本需求的检测方法。 展开更多
关键词 鹅星状病毒 荧光定量rt-PCR TAQMAN探针
原文传递
基于轻量级改进RT-DETR边缘部署算法的绝缘子缺陷检测 被引量:9
18
作者 姜香菊 王瑞彤 马彦鸿 《电工技术学报》 北大核心 2025年第3期842-854,共13页
随着新型电力系统的不断发展建设,输电线路绝缘子状态智能化巡检成为必然趋势。为方便“云-边-端协同架构”进行边缘部署,该文提出一种轻量级RT-DETR目标检测算法。首先,采用RT-DETR作为基线算法降低优化难度,提高鲁棒性;其次,选择轻量... 随着新型电力系统的不断发展建设,输电线路绝缘子状态智能化巡检成为必然趋势。为方便“云-边-端协同架构”进行边缘部署,该文提出一种轻量级RT-DETR目标检测算法。首先,采用RT-DETR作为基线算法降低优化难度,提高鲁棒性;其次,选择轻量级EMO作为算法特征提取主干,充分学习绝缘子目标的长距离特征交互及缺陷小目标的局部特征交互,并提出基于轻量级注意力的尺度内特征交互模块和轻量级跨尺度特征融合模块设计轻量级高效混合编码器;再次,在轻量级高效混合编码器中引入定位信息补充分支、使用DIoU损失函数结合迁移学习训练技巧,缓解轻量化造成的算法精度下降问题;最后,构建多天气条件绝缘子数据集进行训练验证。实验结果表明,相较于基线算法,所提算法检测精度达到97.2%,只损失0.7个百分点,而参数量和计算量分别下降67.8%和71.2%,检测速度提升2.5倍,满足多天气条件下的输电线路绝缘子状态巡检准确率及边缘部署轻量化要求。 展开更多
关键词 绝缘子缺陷检测 rt-DETR算法 轻量化 边缘部署 目标检测算法
在线阅读 下载PDF
改进RT-DETR的煤矿刮板输送机链条故障智能识别方法 被引量:1
19
作者 毛清华 郭文瑾 +2 位作者 苏毅楠 司马俊雷 薛旭升 《煤炭科学技术》 北大核心 2025年第9期469-479,共11页
针对目前煤矿刮板输送机链条多故障识别中的主要问题,提出一种基于改进RT-DETR(Real-Time DEtection TRansformer)的煤矿刮板输送机链条故障智能识别方法。该方法在数据集构建时,运用基于HSV三通道的图像预处理方法对煤矿刮板输送机链... 针对目前煤矿刮板输送机链条多故障识别中的主要问题,提出一种基于改进RT-DETR(Real-Time DEtection TRansformer)的煤矿刮板输送机链条故障智能识别方法。该方法在数据集构建时,运用基于HSV三通道的图像预处理方法对煤矿刮板输送机链条图像进行数据降噪与增强处理,提升图像质量。在改进的RT-DETR算法中,通过采用MobileNetV4作为主干特征网络,提升主干网络特征提取效率;通过将混合编码器中的普通卷积替换为效果更佳的Ghost卷积,降低算法参数量,提升识别速度;通过运用CSPStage特征融合模块和Inner-GIoU损失函数,增强特征利用和融合的能力,提高识别准确率。为了验证算法改进模块的效果,通过消融实验结果表明:改进RT-DETR算法与原RT-DETR算法相比,识别准确度提升1.6%,每秒处理的帧数提升15.5 frames/s,模型大小降低36%,参数量减少35.9%。运用改进RT-DETR算法与YOLOv8m-ghost、YOLOv8m-RT-DETR和YOLOv10s算法进行多故障识别对比实验,对比实验结果表明:改进RT-DETR识别算法在各指标上均效果最优,能够实现刮板输送机链条断链故障和磨损故障的高效准确识别,识别准确率达到97.6%,每秒处理的FPS值达到67.2 frames/s,能够在空载和未满载状态下,满足煤矿刮板输送机链条故障在线高效准确识别的需求。 展开更多
关键词 煤矿刮板输送机 链条故障 rt-DETR 智能识别 MobileNetV4 HSV三通道
在线阅读 下载PDF
A Survey of Testing for 5G:Solutions,Opportunities,and Challenges 被引量:22
20
作者 Ping Zhang Xiaoli Yang +1 位作者 Jianqiao Chen Yuzhen Huang 《China Communications》 SCIE CSCD 2019年第1期69-85,共17页
With the development of wireless communication technology,the fifth generation mobile communications system(5 G) emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in o... With the development of wireless communication technology,the fifth generation mobile communications system(5 G) emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in order to satisfy the requirement of different applications,various advanced 5 G technologies have been developed in full swing.However,before applying these 5 G related technologies in practical systems,effective testing methods are needed to evaluate these technologies in a real,comprehensive,rapid and flexible manner.However,the testing methods are faced with new challenges along with the continuous development of the new 5 G technologies.In this paper,we present a survey of 5 G testing,including solutions and opportunities.In particular,two cases are considered,i.e.,channel modelling and overthe-air(OTA) testing of antenna systems.Specifically,a non-stationary channel model is proposed to characterize and test massive multiple-input multiple-output(MIMO) channel.In addition,we propose two probe subset selection algorithms for three-dimensional(3 D) OTA testing,which minimizes the number of probe antennas while ensuring the accuracy of the target channel emulation.Finally,future research directions and challenges on 5 G testing are given. 展开更多
关键词 5G testing CHANNEL modelling over-the-air testing
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部