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Principal-component estimates of the Kuroshio Current axis and path based on the mathematical verification between satellite altimeter and drifting buoy data 认领
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作者 Zhanpeng Zhuang Zhenli Hui +2 位作者 Guangbing Yang Xinhua Zhao Yeli Yuan 《海洋学报:英文版》 SCIE CAS CSCD 2020年第1期14-24,共11页
We used satellite altimetry data to investigate the Kuroshio Current because of the higher resolution and wider range of observations. In previous studies, satellite absolute geostrophic velocities were used to study ... We used satellite altimetry data to investigate the Kuroshio Current because of the higher resolution and wider range of observations. In previous studies, satellite absolute geostrophic velocities were used to study the spatiotemporal variability of the sea surface velocity field along the current, and extraction methods were employed to detect the Kuroshio axes and paths. However, sea surface absolute geostrophic velocity estimated from absolute dynamic topography should be regarded as the geostrophic component of the actual surface velocity, which cannot represent a sea surface current accurately. In this study, mathematical verification between the climatic absolute geostrophic and bin-averaged drifting buoy velocity was established and then adopted to correct the satellite absolute geostrophic velocities. There were some differences in the characteristics between satellite geostrophic and drifting buoy velocities. As a result, the corrected satellite absolute geostrophic velocities were used to detect the Kuroshio axis and path based on a principal-component detection scheme. The results showed that the detection of the Kuroshio axes and paths from corrected absolute geostrophic velocities performed better than those from satellite absolute geostrophic velocities and surface current estimations. The corrected satellite absolute geostrophic velocity may therefore contribute to more precise day-to-day detection of the Kuroshio Current axis and path. 展开更多
关键词 KUROSHIO AXIS DETECTION KUROSHIO PATH DETECTION MATHEMATICAL VERIFICATION satellite absolute geostrophic velocity principal-component DETECTION
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Cyclodextrin derivatives functionalized highly sensitive chiral sensor based on organic field-effect transistor 认领
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作者 Yifan Wu Xuepeng Wang +2 位作者 Xiaoxuan Li Yin Xiao Yong Wang 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第1期99-102,共4页
Novel highly sensitive chiral organic field-effect transistors(COFET)were developed by directly assembling imidazolium3,5-dimethylphenylcabamoylated-β-cyclodextrin(lm^+-Ph-β-CD)and 3,5-dimethylphenylcarbamoylated-β... Novel highly sensitive chiral organic field-effect transistors(COFET)were developed by directly assembling imidazolium3,5-dimethylphenylcabamoylated-β-cyclodextrin(lm^+-Ph-β-CD)and 3,5-dimethylphenylcarbamoylated-β-CD(Ph-β-CD)respectively onto the semiconductor layer as sensing units.The Im+-Ph-β-CD/COFET afforded better enantioselectivity and a lowest detection concentration of10^-18 L/mol as well as the potentiality in quantitative analysis of commercial medicines. 展开更多
关键词 CHIRAL DISCRIMINATION OFET SENSOR Β-CYCLODEXTRIN derivatives Real-time DETECTION Quantitative DETECTION
Express and sensitive detection of multiple miRNAs via DNA cascade reactors functionalized photonic crystal array 认领
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作者 Yingfei Wang Yuyi Li +3 位作者 Yue Zhang Kewei Ren Huangxian Ju Ying Liu 《中国科学:化学英文版》 SCIE EI CAS CSCD 2020年第5期731-740,共10页
Array based detection techniques with fluorescence signal reading is a powerful tool for multiple targets analysis. However,when applied fluorescence array for micro RNA detection, time-consuming multi-steps surface s... Array based detection techniques with fluorescence signal reading is a powerful tool for multiple targets analysis. However,when applied fluorescence array for micro RNA detection, time-consuming multi-steps surface signal amplification is usually required due to the low abundance of micro RNA in total RNA expressions, which impairs detection efficiency and limits its application in point of care test(POCT) manner. Herein, DNA cascade reactors(DCRs) functionalized photonic crystal(PC)array was fabricated for express and sensitive detections of mi RNA-21 and mi RNA-155. DCRs were assembled by interval conjugation of self-quenched hairpin DNA probes to single strand DNA nanowire synthesized by rolling circle amplification,which generated cascade DNA hybridization reactions in response to target mi RNAwith instant fluorescence recovery signal. PC array patterns with multi-structure colors further amplified fluorescence with their respective photonic bandgaps(PBGs)matching with the emission peaks of fluorescence molecules labelled on DCRs. The as-prepared DCRs functionalized PC array demonstrated express and sensitive simultaneous detections of mi RNA-21 and mi RNA-155 with hundreds f M detection limits only in 15 min, and was successfully applied in fast quantifications of low abundance mi RNAs from cell lysates and spiked mi RNAs from human serum, which would hold great potential for disease diagnosis and therapeutic effect monitoring with a POCT manner. 展开更多
关键词 micro RNA detection photonic crystal array DNA cascade reactors fluorescence amplification express detection
CGNet:cross-guidance network for semantic segmentation 认领
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作者 Zhijie ZHANG Yanwei PANG 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2020年第2期49-64,共16页
Semantic segmentation is a fundamental task in image analysis.The issue of semantic segmentation is to extract discriminative features for distinguishing different objects and recognizing hard examples.However,most ex... Semantic segmentation is a fundamental task in image analysis.The issue of semantic segmentation is to extract discriminative features for distinguishing different objects and recognizing hard examples.However,most existing methods have limitations on resolving this problem.To tackle this problem,we identify the contributions of the edge and saliency information for segmentation and present a novel end-to-end network,termed cross-guidance network(CGNet)to leverage them to benefit the semantic segmentation.The edge and saliency detection network are unified into the CGNet,and model the intrinsic information among them,guiding the process of extracting discriminative features.Specifically,the CGNet attempts to extract segmentation,edge,and salient features,simultaneously.Then it transfers them into the cross-guidance module(CGM)to generate the pre-knowledge features based on the modeled information,optimizing the context feature extraction process.The proposed approach is extensively evaluated on PASCAL VOC 2012,PASCAL-Person-Part,and Cityscapes,and achieves state-of-the-art performance,demonstrating the superiority of the proposed approach. 展开更多
关键词 SEMANTIC SEGMENTATION fully convolutional networks pyramid NETWORK edge DETECTION saliency DETECTION cross-guidance
Asymmetric polymerase chain reaction and loop-mediated isothermal amplification(AP-LAMP) for ultrasensitive detection of microRNAs 认领
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作者 Ruili Wang Ling Lan +1 位作者 Li Liu Liang Cheng 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第1期159-162,共4页
In this manuscript,we first report an ultrasensitive detection assay of microRNA by combing asymmetric polymerase chain reaction(A-PCR)and loop-mediated isothermal amplification(LAMP)technology.Using A-PCR obtained an... In this manuscript,we first report an ultrasensitive detection assay of microRNA by combing asymmetric polymerase chain reaction(A-PCR)and loop-mediated isothermal amplification(LAMP)technology.Using A-PCR obtained an extended single strand to form LAMP stem-loop structure under isothermal amplification conditions.We used miRNAs as a loop primer probe in LAMP reaction and completed its ultrasensitive and rapid detection.The established method furnished a fast,specific and efficient detection of target miRNA with a detection limit as low as 10 amol/L in 90 min. 展开更多
关键词 microRNA LAMP ASYMMETRIC PCR Ultrasensitive DETECTION RAPID DETECTION
MHSS ARAIM Algorithm Combined with Gross Error Detection 认领
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作者 Yabin ZHANG Li WANG +1 位作者 Lihong FAN Xuanyu QU 《测绘学报(英文版)》 2020年第1期36-44,共9页
Due to some shortcomings in the current multiple hypothesis solution separation advanced receiver autonomous integrity monitoring(MHSS ARAIM)algorithm,such as the weaker robustness,a number of computational subsets wi... Due to some shortcomings in the current multiple hypothesis solution separation advanced receiver autonomous integrity monitoring(MHSS ARAIM)algorithm,such as the weaker robustness,a number of computational subsets with the larger computational load,a method combining MHSS ARAIM with gross error detection is proposed in this paper.The gross error detection method is used to identify and eliminate the gross data in the original data first,then the MHSS ARAIM algorithm is used to deal with the data after the gross error detection.Therefore,this makes up for the weakness of the MHSS ARAIM algorithm.With the data processing and analysis from several international GNSS service(IGS)and international GNSS monitoring and assessment system(iGMAS)stations,the results show that this new algorithm is superior to MHSS ARAIM in the localizer performance with vertical guidance down to 200 feet service(LPV-200)when using GPS and BDS measure data.Under the assumption of a single-faulty satellite,the effective monitoring threshold(EMT)is improved about 22.47%and 9.63%,and the vertical protection level(VPL)is improved about 32.28%and 12.98%for GPS and BDS observations,respectively.Moreover,under the assumption of double-faulty satellites,the EMT is improved about 80.85%and 29.88%,and the VPL is improved about 49.66%and 18.24%for GPS and BDS observations,respectively. 展开更多
关键词 GROSS ERROR DETECTION ARAIM FAULT DETECTION and IDENTIFICATION MHSS ARAIM
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Molecular Detection of Sugarcane Ratoon Stunting Disease in Hainan Sugarcane-growing Areas 认领
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作者 Shen Linbo Xiong Guoru +6 位作者 Feng Xiaoyan Wang Wenzhi Feng Cuilian Zhao Tingting Wang Jungang Wu Nannan Zhang Shuzhen 《Plant Diseases and Pests(植物病虫害研究:英文版)》 CAS 2020年第1期6-9,共4页
[Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-grow... [Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-growing areas in Hainan Province,and RSD was detected by PCR assay with specific primers.[Result]RSD was detected out in 41 out of 270 sugarcane samples,with an average detection rate of15.19%.The detection rates of RSD were different in six sugarcane-growing areas;the detection rate of RSD in Danzhou sugarcane-growing area was the highest of 22.00%;the detection rate of RSD in Lingao sugarcane-growing area was the lowest of 9.26%.RSD was detected out in 8 out of10 main sugarcane cultivars,among which Xintaitang 22 suffered the heaviest damage,with the positive detection rate of 45.83%;RSD had not been detected out in Zhongtang 1 and Zhongtang 2,while the positive detection rates of RSD in the remaining seven sugarcane cultivars were10.00%-31.25%.[Conclusion]RSD commonly occurs in Hainan sugarcane-growing areas.The research results provide a basis for scientific prevention and control of RSD and promotion and application of healthy virus-free sugarcane seedlings. 展开更多
关键词 SUGARCANE Sugarcane ratoon stunting disease(RSD) Molecular detection Detection rate HAINAN
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氨基酸席夫碱类小分子探针衍生物电子光谱的检测研究 认领
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作者 赵小菁 徐敬敬 +1 位作者 赖国华 阮文娟 《广州化工》 CAS 2020年第4期75-77,共3页
研究了氨基酸席夫碱类小分子探针衍生物的电子光谱检测方法。以CHCl 3:C 2H5 OH=1:1的混合溶液为溶剂,配制溶液浓度为5.0×10^-4 mol/L,紫外可见光谱测试条件:室温,样品池为1 cm×1 cm×1 cm石英池,设置波长范围190~1100 nm... 研究了氨基酸席夫碱类小分子探针衍生物的电子光谱检测方法。以CHCl 3:C 2H5 OH=1:1的混合溶液为溶剂,配制溶液浓度为5.0×10^-4 mol/L,紫外可见光谱测试条件:室温,样品池为1 cm×1 cm×1 cm石英池,设置波长范围190~1100 nm,测试波长范围200~700 nm,波长分辨率为0.1 nm。荧光光谱测试条件:室温,激发波长λex为355 nm,样品池为1 cm×1 cm×1 cm石英池,狭缝宽度5.5 nm,记谱范围为350~600 nm。结果氨基酸席夫碱化合物的紫外可见光谱有4个主要吸收峰(E2带、K带、B带、R带),λmax值不同,是由于氨基酸席夫碱R基不同所致;而荧光光谱中,铜配合物的荧光强度与锌配合物相比很低,原因是金属配合物的荧光性质与过渡金属离子的d电子数直接相关。 展开更多
关键词 氨基酸席夫碱 探针 电子光谱 检测
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Defect detection method based on 2D entropy image segmentation 认领
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作者 迟大钊 刚铁 《中国焊接:英文版》 EI CAS 2020年第1期45-49,共5页
In order to improve the work efficiency of non-destructive testing(NDT)and the reliability of NDT results,an automatic method to detect defects in the ultrasonic image was researched.According to the characterization ... In order to improve the work efficiency of non-destructive testing(NDT)and the reliability of NDT results,an automatic method to detect defects in the ultrasonic image was researched.According to the characterization of ultrasonic D-scan image,clutter wave suppression and de-noising were presented firstly.Then,the image is processed by binaryzation using KSW 2 D entropy based on image segmentation method.The results showed that,the global threshold based segmentation method was somewhat ineffective for D-scan image because of under-segmentation.Especially,when the image is big in size,small targets which are composed by a small amount of pixels are often undetected.Whereas,local threshold based image segmentation method is effective in recognizing small defects because it takes local image character into account. 展开更多
关键词 ultrasonic testing defect detection 2D entropy image segmentation
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金银花中有机磷农药残留分析及其冲泡过程迁移模型研究 认领
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作者 李建勋 王玉珍 +3 位作者 卢嘉 徐迪 单吉浩 范蓓 《食品科学技术学报》 CAS CSCD 北大核心 2020年第3期119-126,共8页
为确保消费者饮茶安全,建立了QuEChERS-GC-MS/MS快速测定金银花和其茶汤中6种有机磷农药(对硫磷、倍硫磷、特丁硫磷、治螟磷、丙溴磷、灭线磷)残留的检测方法。金银花和茶汤分别经乙腈和乙酸乙酯提取、盐析离心、混合净化剂(10 mg MWCNT... 为确保消费者饮茶安全,建立了QuEChERS-GC-MS/MS快速测定金银花和其茶汤中6种有机磷农药(对硫磷、倍硫磷、特丁硫磷、治螟磷、丙溴磷、灭线磷)残留的检测方法。金银花和茶汤分别经乙腈和乙酸乙酯提取、盐析离心、混合净化剂(10 mg MWCNTs、15 mg PSA、150 mg无水硫酸镁)净化、0.22μm滤膜过滤后,供GC-MS/MS检测。结果表明:金银花和茶汤中,有机磷农药在1~1000μg/kg和1~1000μg/L呈现良好的线性关系,R2>0.991;在4个添加水平下,回收率在67.2%~110.3%,相对标准偏差小于19%(n=6);金银花和茶汤中,有机磷农药定量限分别为1μg/kg和1μg/L。在此基础上,深入研究了金银花在冲泡过程中6种有机磷农药的迁移预测模型,表明农药迁移率(TR)与农药的正辛醇-水分配系数(Kow)关联性较大,由此获得预测模型为lg TR=-0.5362 lg Kow+3.9152(lg Kow>3),R2=0.914,拟合度较好;而农药迁移率与水溶解度(Ws)并未表示出关联性。该检测方法和迁移模型的建立将有利于更深层次认知农药化学污染物在金银花浸泡过程中的迁移行为,以期为制定金银花中有机磷农药最大残留限量标准提供科学依据和技术支撑。 展开更多
关键词 金银花 茶汤 有机磷农药 检测 迁移模型
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A New Fire Detection Method Using a Multi-Expert System Based on Color Dispersion, Similarity and Centroid Motion in Indoor Environment 认领
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作者 Teng Wang Leping Bu +2 位作者 Zhikai Yang Peng Yuan Jineng Ouyang 《自动化学报:英文版》 EI CSCD 2020年第1期263-275,共13页
In this paper, a video fire detection method is proposed, which demonstrated good performance in indoor environment. Three main novel ideas have been introduced. Firstly, a flame color model in RGB and HIS color space... In this paper, a video fire detection method is proposed, which demonstrated good performance in indoor environment. Three main novel ideas have been introduced. Firstly, a flame color model in RGB and HIS color space is used to extract pre-detected regions instead of traditional motion differential method, as it’s more suitable for fire detection in indoor environment. Secondly, according to the flicker characteristic of the flame, similarity and two main values of centroid motion are proposed. At the same time, a simple but effective method for tracking the same regions in consecutive frames is established. Thirdly,a multi-expert system consisting of color component dispersion,similarity and centroid motion is established to identify flames.The proposed method has been tested on a very large dataset of fire videos acquired both in real indoor environment tests and from the Internet. The experimental results show that the proposed approach achieved a balance between the false positive rate and the false negative rate, and demonstrated a better performance in terms of overall accuracy and F standard with respect to other similar fire detection methods in indoor environment. 展开更多
关键词 Index Terms—Color DISPERSION CENTROID MOTION EXPERT system RGB-HIS COLOR model SIMILARITY video fire detection
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A simple chemical method for the synthesis of Cu^2+ engrafted MgAl2O4 nanoparticles: Efficient fluoride adsorbents, photocatalyst and latent fingerprint detection 认领
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作者 Arnab Mukherjee Mrinal KAdak +1 位作者 Prasanta Dhak Debasis Dhak 《环境科学学报:英文版》 SCIE EI CAS CSCD 2020年第2期301-315,共15页
An adaptable, energy efficient chemical process is employed to synthesize Cu^2+engrafted MgAl2O4 nanoparticles(Mg1-xCuxAl2O4, x = 0, 0.1, 0.3, 0.5 abbreviated as MCA0, MCA1, MCA3,and MCA5 respectively), using chelatin... An adaptable, energy efficient chemical process is employed to synthesize Cu^2+engrafted MgAl2O4 nanoparticles(Mg1-xCuxAl2O4, x = 0, 0.1, 0.3, 0.5 abbreviated as MCA0, MCA1, MCA3,and MCA5 respectively), using chelating ligand and the calcination temperature was determined by the thermogravimetric analysis of the precursor mass.They acted as good fluoride adsorbent in the presence of co-ions, different pH(2–11) via chemisorption revealed from Fourier-transform infrared spectroscopy(FTIR) and photodegraded Methylene Blue(MB).The satisfactory results were for MCA1(specific surface area 25.05 m^2/g) with 97%fluoride removal at pH 7.0 for the 10 mg/L initial fluoride concentration for 1.5 g/L adsorbent dose with 45 min contact time obeying the Langmuir isotherm model with negative thermodynamic parameters and 4 mmol of MCA3 with 98.51% photodegradation for 10-5 mol/L MB solution obeying pseudo-second-order and pseudo-first-order kinetics respectively.The proposed photodegradation mechanism of MB was established by the FTIR and high-performance liquid chromatography(HPLC) analysis.The nanoparticles are cubic, estimated through X-ray diffraction(XRD) and transmission electron microscopy(TEM) analysis.The band gap energies, grain size, and the effective working pH were estimated by diffuse reflectance spectra(DRS), scanning electron microscope(SEM), and zero-point potential analysis respectively.A soil candle with MCA1 also fabricated for the household purpose and tested with some fluorinated field samples.The MCA3 was able to enhance the latent fingerprint on smooth surfaces. 展开更多
关键词 FLUORIDE adsorbent Photocatalysis Mechanism FINGERPRINT DETECTION Kr?ger-Vink notation Soil CANDLE
基于方向加权多级门限DP-TBD的目标轨迹检测算法 认领
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作者 吴帅 谢春思 +2 位作者 李进军 刘志赢 桑雨 《兵器装备工程学报》 CAS 北大核心 2020年第3期149-153,共5页
在分析了双门限DP-TBD算法及多级门限DP-TBD算法的优缺点后,对多级门限DP-TBD算法进行了改进,提出了方向加权多级门限DP-TBD算法。这种算法在牺牲计算量的前提下,减少了伪轨迹的数量,提高了对目标轨迹检测和跟踪的准确率,对反舰导弹末... 在分析了双门限DP-TBD算法及多级门限DP-TBD算法的优缺点后,对多级门限DP-TBD算法进行了改进,提出了方向加权多级门限DP-TBD算法。这种算法在牺牲计算量的前提下,减少了伪轨迹的数量,提高了对目标轨迹检测和跟踪的准确率,对反舰导弹末制导雷达对岛岸附近弱小目标的检测和跟踪具有重要的借鉴意义。 展开更多
关键词 DP-TBD 多级门限 检测
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甲醛检测模组的校准及其在微信推送应用的实现 认领
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作者 刘卫玲 王昊冉 +1 位作者 陈祺 常晓明 《国外电子测量技术》 2020年第2期98-101,共4页
随着生活水平的提高,人们对住房环境质量要求越来越高,但房屋装修材料中难免含有诸如甲醛之类的有害物质。提出了一种LabVIEW环境下由甲醛检测模组,MCU和物联网模块构成的语音控制与微信推送的甲醛检测系统,利用LabVIEW图形化显示和存... 随着生活水平的提高,人们对住房环境质量要求越来越高,但房屋装修材料中难免含有诸如甲醛之类的有害物质。提出了一种LabVIEW环境下由甲醛检测模组,MCU和物联网模块构成的语音控制与微信推送的甲醛检测系统,利用LabVIEW图形化显示和存储的数据,实时显示和记录所处环境中的甲醛浓度值,及时反映环境中甲醛浓度的变化,分辨率可达0.0001mg/m~3,同时用物联网模块进行微信推送,从而实现用户及时掌握远程环境中的甲醛浓度变化情况。在智能家居的应用中具有实用价值。 展开更多
关键词 甲醛 检测 LABVIEW 微信 信息推送
浅谈泵送产品的公告试验检测 认领
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作者 谢艳群 钟琦 周佳 《中小企业管理与科技》 2020年第7期141-142,共2页
论文针对泵送产品公告试验检测的现状,详述了公告试验检测方案中的关键控制点,并就目前检测过程中存在的问题提出了建议。
关键词 公告 检测 控制点
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郑州地区1548例住院呼吸道感染儿童9项呼吸道常见病原体检测分析 认领
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作者 杨建丽 杨俊梅 《国际医药卫生导报》 2020年第3期303-306,共4页
目的调查郑州地区1548例住院呼吸道感染儿童9项呼吸道常见病原体的检测结果。方法选取郑州地区2016年1月至2018年12月收治的1548例住院呼吸道感染儿童为研究对象并开展回顾性分析,所有患儿均采用间接免疫荧光法检测9项支原体IgM抗体,比... 目的调查郑州地区1548例住院呼吸道感染儿童9项呼吸道常见病原体的检测结果。方法选取郑州地区2016年1月至2018年12月收治的1548例住院呼吸道感染儿童为研究对象并开展回顾性分析,所有患儿均采用间接免疫荧光法检测9项支原体IgM抗体,比较不同性别、不同年龄段、不同季节呼吸道感染儿童的不同病原体阳性结果。结果1548例住院呼吸道感染儿童中,311例患儿9项病原体检测结果为阳性,占比为20.09%;311例病原体阳性患儿中,以MP检出率最高,为41.16%,其次是Lp1,检出率为27.01%;235例单项病原体感染检出者中,以MP检出率最高,为34.89%,其次是Lp1,检出率为26.81%;76例混合病原体感染检出者中,以MP检出率最高,为60.53%,其次是RSV,检出率为31.58%;女童的MP、INFB阳性率明显高于男童(P<0.05);MP、INFB阳性率在各年龄段间差异有统计学意义(P<0.05),1个月~1岁组的MP、INFB阳性率明显低于其他各年龄段(P<0.05);春、冬季的INFB阳性率明显高于夏、秋季(P<0.05)。结论本调查研究中,MP为主要呼吸道感染的病原体,且呼吸道感染患儿病原体与年龄、季节、性别均具有一定关系,应及时准确检测病原体,以为临床诊疗提供可靠依据。 展开更多
关键词 呼吸道感染 病原体 检测
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硼氮共掺杂石墨烯量子点及对Hg^2+的选择性检测 认领
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作者 袁才登 杨盼星 +2 位作者 苏洁 郭睿威 姚芳莲 《天津大学学报:自然科学与工程技术版》 EI CSCD 北大核心 2020年第2期207-213,共7页
以柠檬酸、乙二胺和苯硼酸为原料,采用一步水热法制备了高荧光量子产率、长荧光寿命的硼氮共掺杂石墨烯量子点(B,N-GQDs).通过透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FT-IR)、X射线光电子能谱仪(XPS)、紫外-可见分光光度计(UV-Vis... 以柠檬酸、乙二胺和苯硼酸为原料,采用一步水热法制备了高荧光量子产率、长荧光寿命的硼氮共掺杂石墨烯量子点(B,N-GQDs).通过透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FT-IR)、X射线光电子能谱仪(XPS)、紫外-可见分光光度计(UV-Vis)及荧光光谱仪(PL)对量子点进行了表征.结果表明,B,N-GQDs粒径范围为1.46~3.54 nm,平均粒径为(2.34±0.50)nm,具有明显的晶格条纹结构;表面官能团(—OH,—NH和—BOH)的存在,有利于与金属离子结合从而实现对金属离子的检测;在pH=5.0~10.0和NaCl浓度0~1.0 mol/L的酸碱盐环境下,B,N-GQDs具有优异的荧光稳定性.由于B,N-GQD与金属离子具有结合作用,因此它被用作检测金属离子的荧光探针.考察了15种金属离子(K^+、Na^+、Ba^2+、Ni^2+、Zn^2+、Pb^2^+、Li^+、Cu^2+、Ag^+、Mn^2+、Fe^2+、Mg^2+、Fe^3+、Ca^2+和Hg^2+)对B,N-GQDs荧光强度的影响,发现仅Mg^2+、Fe^3+、Ca^2+和Hg^2+对其荧光有猝灭作用.考虑到Hg^2+是重要的有毒污染物,因此灵敏、选择性地检测Hg^2+对人体健康和环境保护至关重要.在单一汞离子体系中,其线性范围为2.0~20.0μmol/L,检测限为0.05μmol/L;在复杂体系(Mg^2+、Fe^3+、Ca^2+和Hg^2+)中,采用掩蔽剂NaF能够实现对Hg^2+浓度的准确测定,其检测误差范围为-4.432%~2.600%.B,N-GQDs有望在多金属离子响应体系中实现对Hg^2+的快速检测.此外,探究了Hg^2+对B,N-GQDs荧光的猝灭机理,当加入Hg^2+后,B,N-GQDs的荧光寿命从原来的12.86 ns缩短为11.34 ns,符合动态猝灭机理. 展开更多
关键词 石墨烯量子点 荧光 选择性 检测 污染物 汞离子
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"病原微生物监测、检测、溯源与疫苗研发关键前沿问题学术交流会"专家共识 认领
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作者 杨瑞馥 +2 位作者 阚飙 舒跃龙 徐建青 《中华预防医学杂志》 CAS CSCD 北大核心 2020年第1期42-46,共5页
来自疾病控制、高校科研院所、医疗机构的48位专家于2019年10月24—27日围绕我国传染病监测网络面临的挑战与机遇,病原微生物检测与溯源技术的探索和未来发展需求,以及疫苗研发面临的关键问题等内容展开了深入的讨论,并达成共识:(1)我... 来自疾病控制、高校科研院所、医疗机构的48位专家于2019年10月24—27日围绕我国传染病监测网络面临的挑战与机遇,病原微生物检测与溯源技术的探索和未来发展需求,以及疫苗研发面临的关键问题等内容展开了深入的讨论,并达成共识:(1)我国传染病监测网络亟须跨部门进行业务和数据整合,建设并完善以人为核心的全生命周期疾病监测与健康管理系统;(2)传统病原分离培养技术仍需进一步规范和加强,病原微生物检测技术亟须发展多靶标、超灵敏、高特异、便捷化和数字化的高中通量的新技术,并发展基于致病共栖菌谱新靶标的疾病诊断新技术;(3)亟须建立基因组学、生物信息学、微生物学等多学科交叉的溯源技术体系;(4)疫苗研发亟须相关基础研究支撑,并需加强疫苗接种策略和上市后评价与评估策略的研究。同时根据以上问题提出了专家建议。 展开更多
关键词 病原微生物 监测 检测 溯源 疫苗
高强度钢结构承压区域的检测方法 认领
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作者 刘春波 《兵器材料科学与工程》 CAS CSCD 北大核心 2020年第2期108-112,共5页
为提高传统钢结构承压区域的可靠性和精准度,提出基于超声波检测的高强度钢结构承压区域的检测方法。利用精确微分方程描述杆件的大挠度变形,根据测试点与布局方案,分析超声波检测原理,计算钢结构与混凝土间的缝隙宽度,利用瞬时应力波... 为提高传统钢结构承压区域的可靠性和精准度,提出基于超声波检测的高强度钢结构承压区域的检测方法。利用精确微分方程描述杆件的大挠度变形,根据测试点与布局方案,分析超声波检测原理,计算钢结构与混凝土间的缝隙宽度,利用瞬时应力波对高强度钢结构的承压形变量展开分析,进而对空隙进行灌溉与补修,并试验验证研究方法的有效性。结果表明:本研究提出的钢结构承压检测技术具有稳定性强、精准度高等优点,能够满足钢结构建筑工程的实际安全要求。 展开更多
关键词 高强度 钢结构 瞬时应力波 承压区域 检测
H9和H10亚型禽流感病毒三重RT-PCR检测方法的建立 认领
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作者 李丹 谢芝勋 +10 位作者 李孟 罗思思 谢丽基 张民秀 黄娇玲 范晴 王盛 谢志勤 邓显文 曾婷婷 张艳芳 《江西农业学报》 CAS 2020年第4期113-117,共5页
根据GenBank中H9和H10亚型禽流感病毒(AIV)的HA基因及所有亚型AIV M基因的保守序列,分别设计3对特异性引物,并优化退火温度和引物浓度及其配比等条件,建立了可同时鉴别检测H9和H10亚型AIV的三重RT-PCR检测方法。特异性实验结果表明,该... 根据GenBank中H9和H10亚型禽流感病毒(AIV)的HA基因及所有亚型AIV M基因的保守序列,分别设计3对特异性引物,并优化退火温度和引物浓度及其配比等条件,建立了可同时鉴别检测H9和H10亚型AIV的三重RT-PCR检测方法。特异性实验结果表明,该方法可以特异性地扩增出H9、H10亚型AIV及M基因对应大小的目的条带,而对其余亚型AIV仅M基因出现特异性条带,其它禽病病原体均未扩增出任何特异性条带。敏感性实验结果表明,该方法对H9、H10亚型HA基因及M基因质粒的扩增下限均为5×104拷贝/μL。此外,该方法对临床样品的检测结果与病毒分离及测序结果完全一致。 展开更多
关键词 禽流感病毒 H9亚型 H10亚型 M基因 三重RT-PCR 检测
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