目的比较荷兰Patho Finder公司多重荧光定量PCR技术(Respi Finder 2SMART试剂盒,简称Respi Finder检测)和加拿大Luminex公司液态芯片技术(呼吸道病毒检测试剂盒,简称x TAG RVP)对下呼吸道标本病毒检测的结果。方法收集2015年1至12月于...目的比较荷兰Patho Finder公司多重荧光定量PCR技术(Respi Finder 2SMART试剂盒,简称Respi Finder检测)和加拿大Luminex公司液态芯片技术(呼吸道病毒检测试剂盒,简称x TAG RVP)对下呼吸道标本病毒检测的结果。方法收集2015年1至12月于北京协和医院疑似病毒性肺炎住院患者100例下呼吸道标本,分别利用Respi Finder和x TAG RVP检测试剂进行常见呼吸道病毒核酸检测,并全部进行PCR及测序分析,比较两种方法的敏感性和特异性。结果 100份下呼吸道标本经Respi Finder和x TAG RVP方法检测,阳性率分别为60.0%和51.0%,混合感染率均为8.0%。两种方法结果一致率为80.0%。以PCR及测序结果为准,经Respi Finder和x TAG RVP方法检测的敏感性分别为97.9%和94.3%,特异性分别为74.5%和97.9%,阳性预测值分别为78.3%和98.0%,阴性预测值分别为95.0%和93.9%,两法检测特异性及阳性预测值差异有统计学意义(P<0.05)。结论与Respi Finder方法相比,x TAG RVP对常见呼吸道病毒检测的特异性较好,敏感性相当,对呼吸道病毒的检测性能优于Respi Finder检测。展开更多
The rapid development of image processing techniques has made it extremely easy to alter the content of images or create newimages.So photographs,which appear in magazines,social media,and political attacks,can no lon...The rapid development of image processing techniques has made it extremely easy to alter the content of images or create newimages.So photographs,which appear in magazines,social media,and political attacks,can no longer be trusted.A novel and effective technique is proposed in this paper to expose image forgery using inconsistent reflection vanishing point(RVP).More specifically,the definition of error distance is given,sin^2()-based function is proposed to normalize error distance,and a reasonable threshold value is set to detect image forgery.The experimental data and results are presented to demonstrate the accuracy and effectiveness of the technique.展开更多
As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly e...As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly efficient,stable,and compact,making them suitable for eroengine lubricating oil systems.However,they suffer from performance degradation under prolonged high-speed operation,owing to vane tip wear and clearance expansion.This study numerically investigates the effects of vane tip clearance on cavitation and gas-liquid twophase flow in a high-speed RVP.The RNG k-εturbulence model,Singhal full cavitation model,and volume-of-fluid(VOF)multiphase flow model are employed.The results indicate that under single-phase oil inlet conditions,increased vane tip clearance has a minimal influence on cavitation in the pump chamber,but reduces outlet flow pulsation amplitude and volumetric efficiency.Pressure fluctuations at the pump outlet remain relatively stable,with the dominant pulsation frequency being equal to the rotational frequency.Under two-phase oil-gas conditions,increased vane tip clearance leads to decreased instantaneous flow fluctuation,induces uneven oil-gas phase distribution in the pump chamber,lowers the maximum outlet pressure,and increases leakage.Spectral analysis reveals that the dominant frequency of pressure pulsations corresponds to the shaft rotation and that the secondary frequency is the vane frequency.To optimize performance and reduce leakage,it is recommended to maintain a vane tip clearance of 0.035 mm and avoid operating the pump under high-gas-content conditions.These results provide theoretical guidance for designing and selecting RVPs,with significant implications for the further development of eroengine lubricating oil systems.展开更多
文摘目的比较荷兰Patho Finder公司多重荧光定量PCR技术(Respi Finder 2SMART试剂盒,简称Respi Finder检测)和加拿大Luminex公司液态芯片技术(呼吸道病毒检测试剂盒,简称x TAG RVP)对下呼吸道标本病毒检测的结果。方法收集2015年1至12月于北京协和医院疑似病毒性肺炎住院患者100例下呼吸道标本,分别利用Respi Finder和x TAG RVP检测试剂进行常见呼吸道病毒核酸检测,并全部进行PCR及测序分析,比较两种方法的敏感性和特异性。结果 100份下呼吸道标本经Respi Finder和x TAG RVP方法检测,阳性率分别为60.0%和51.0%,混合感染率均为8.0%。两种方法结果一致率为80.0%。以PCR及测序结果为准,经Respi Finder和x TAG RVP方法检测的敏感性分别为97.9%和94.3%,特异性分别为74.5%和97.9%,阳性预测值分别为78.3%和98.0%,阴性预测值分别为95.0%和93.9%,两法检测特异性及阳性预测值差异有统计学意义(P<0.05)。结论与Respi Finder方法相比,x TAG RVP对常见呼吸道病毒检测的特异性较好,敏感性相当,对呼吸道病毒的检测性能优于Respi Finder检测。
基金Fundamental Research Funds for the Central Universities,China(No.2232015D3-25)
文摘The rapid development of image processing techniques has made it extremely easy to alter the content of images or create newimages.So photographs,which appear in magazines,social media,and political attacks,can no longer be trusted.A novel and effective technique is proposed in this paper to expose image forgery using inconsistent reflection vanishing point(RVP).More specifically,the definition of error distance is given,sin^2()-based function is proposed to normalize error distance,and a reasonable threshold value is set to detect image forgery.The experimental data and results are presented to demonstrate the accuracy and effectiveness of the technique.
基金supported by the National Natural Science Foundation of China(Grant No.52376031)the School-Enterprise Collaborative Innovation Fund for graduate students of Xi’an University of Technology(Grant No.252062402).
文摘As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly efficient,stable,and compact,making them suitable for eroengine lubricating oil systems.However,they suffer from performance degradation under prolonged high-speed operation,owing to vane tip wear and clearance expansion.This study numerically investigates the effects of vane tip clearance on cavitation and gas-liquid twophase flow in a high-speed RVP.The RNG k-εturbulence model,Singhal full cavitation model,and volume-of-fluid(VOF)multiphase flow model are employed.The results indicate that under single-phase oil inlet conditions,increased vane tip clearance has a minimal influence on cavitation in the pump chamber,but reduces outlet flow pulsation amplitude and volumetric efficiency.Pressure fluctuations at the pump outlet remain relatively stable,with the dominant pulsation frequency being equal to the rotational frequency.Under two-phase oil-gas conditions,increased vane tip clearance leads to decreased instantaneous flow fluctuation,induces uneven oil-gas phase distribution in the pump chamber,lowers the maximum outlet pressure,and increases leakage.Spectral analysis reveals that the dominant frequency of pressure pulsations corresponds to the shaft rotation and that the secondary frequency is the vane frequency.To optimize performance and reduce leakage,it is recommended to maintain a vane tip clearance of 0.035 mm and avoid operating the pump under high-gas-content conditions.These results provide theoretical guidance for designing and selecting RVPs,with significant implications for the further development of eroengine lubricating oil systems.
