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
High speed pseudorandom modulation and photon counting techniques are applied to a three-dimensional imaging lidar system.The specific structure and working principle of the lidar system is described.The actual detect...High speed pseudorandom modulation and photon counting techniques are applied to a three-dimensional imaging lidar system.The specific structure and working principle of the lidar system is described.The actual detector efficiency of a single-photon detector in an imaging system is discussed,and the result shows that a variety of reasons lead to the decrease in detection efficiency.A series of ranging and imaging experiments are conducted,and a series of high-resolution three-dimensional images and a distance value of 1200 m of noncooperative targets are acquired.展开更多
In order to suppressing the particle deposition on vortex finder,a series of gas cyclones with the secondary swirling clean gas were developed inspired by the gas purge effect.Effects of the width and extension length...In order to suppressing the particle deposition on vortex finder,a series of gas cyclones with the secondary swirling clean gas were developed inspired by the gas purge effect.Effects of the width and extension length of the flow channel as well as the secondary inlet velocity and running time on the particle deposition pattern,the deposited particle mass and the cyclones'performance were experimentally investigated,respectively.The results show that the ultrafine particles(Stokes number Stk<0.0358)are mainly loose deposited on the walls under the secondary gas.Compare to the conventional cyclone with single tangential inlet,the total deposited particle mass of the improved cyclone has a maximum reduction more than 60%,and the collecting efficiency is increased up to 97.5%under the basically same pressure drop.The corresponding no-deposition area is increased by about 13%,and remains constant in spite of extending the running time.Moreover,an interesting phenomenon named"self-cleaning effect"of the vortex finder was captured for the gas cyclones,and mechanism of the secondary clean gas on the particle deposition is preliminarily analyzed.The results can deepen the understanding of the particle deposition on the vortex finder and guide the design of the anti-coking gas cyclones.展开更多
We describe the algorithm to reconstruct the charged tracks for BESⅢ main drift chamber at BEPCⅡ, including the track finding and fitting. With a new method of the Track Segment Finder （TSF）, the results of presen...We describe the algorithm to reconstruct the charged tracks for BESⅢ main drift chamber at BEPCⅡ, including the track finding and fitting. With a new method of the Track Segment Finder （TSF）, the results of present study indicate that the algorithm can reconstruct the charged tracks over a wide range of momentum with high efficiency, while improving the robustness against the background noise in the drift chamber. The overall performances, including spatial resolution, momentum resolution and secondary vertices reconstruction efficiency, etc. satisfy the requirements of BESⅢ experiment.展开更多
Maize （Zea mays） is the most widely grown grain crop in the world, playing important roles in agriculture and industry. However, the functions of maize genes remain largely unknown. High-quality genome- wide transcr...Maize （Zea mays） is the most widely grown grain crop in the world, playing important roles in agriculture and industry. However, the functions of maize genes remain largely unknown. High-quality genome- wide transcriptome datasets provide important biological knowledge which has been widely and suc- cessfully used in plants not only by measuring gene expression levels but also by enabling co-expression analysis for predicting gene functions and modules related to agronomic traits. Recently, thousands of maize transcriptomic data are available across different inbred lines, development stages, tissues, and treatments, or even across different tissue sections and cell lines. Here, we integrated 701 transcriptomic and 108 epigenomic data and studied the different conditional networks with multi-dimensional omics levels. We constructed a searchable, integrative, one-stop online platform, the maize conditional co- expression network （MCENet） platform. MCENet provides 10 global/conditional co-expression net- works, 5 network accessional analysis toolkits （i.e., Network Search, Network Remodel, Module Finder, Network Comparison, and Dynamic Expression View） and multiple network functional support toolkits （e.g., motif and module enrichment analysis）. We hope that our database might help plant research communities to identify maize functional genes or modules that regulate important agronomic traits.展开更多
This note reports a new type of incoherent pulse laser Doppler lidar velocimeter with iodine molecular filter as a frequency discriminator. Its transmitter subsystem applies a Nd:YAG pulse laser which is injected with...This note reports a new type of incoherent pulse laser Doppler lidar velocimeter with iodine molecular filter as a frequency discriminator. Its transmitter subsystem applies a Nd:YAG pulse laser which is injected with a single longitudinal-mode diode pumped continuous seeder laser. The field experiment proved that this velocimeter measurement results are consistent with those measured by photoelectric velocimeter. Measurements of eight different velocities show that the standard deviation is 0.56m/s, the range resolution is 3.75m.展开更多
Due to the portability and anti-interference ability,vision-based shipborne aircraft automatic landing systems have attracted the attention of researchers.In this paper,a Monocular Camera and Laser Range Finder(MC-LRF...Due to the portability and anti-interference ability,vision-based shipborne aircraft automatic landing systems have attracted the attention of researchers.In this paper,a Monocular Camera and Laser Range Finder(MC-LRF)-based pose measurement system is designed for shipborne aircraft automatic landing.First,the system represents the target ship using a set of sparse landmarks,and a two-stage model is adopted to detect landmarks on the target ship.The rough 6D pose is measured by solving a Perspective-n-Point problem.Then,once the rough pose is measured,a region-based pose refinement is used to continuously track the 6D pose in the subsequent image sequences.To address the low accuracy of monocular pose measurement in the depth direction,the designed system adopts a laser range finder to obtain an accurate range value.The measured rough pose is iteratively optimized using the accurate range measurement.Experimental results on synthetic and real images show that the system achieves robust and precise pose measurement of the target ship during automatic landing.The measurement means error is within 0.4in rotation,and 0.2%in translation,meeting the requirements for automatic fixed-wing aircraft landing.展开更多
Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firs...Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firstly, 2D sequential laser range finder data were aligned using a Dead-Reckoning （DR） and GPS loeaHzation method based on extended Kalman filter. Secondly, curb points were extracted from multi.frame laser data based on spatial-temporal correlation analysis. Finally. the straight and curved curbs were detected by coordinate axis conversion least square linear fitting method and piecewise weighted least square fitting model respectively. The proposed method can detect both raised and sunken curbs robustly in campus environment. The proposed method has been verified in a real robot platform.展开更多
In this paper, we take the model of Laser range finder based on synchronized scanner as example, show how to use data fusion method in the process of sensor model designing to get more robust output. Also we provide o...In this paper, we take the model of Laser range finder based on synchronized scanner as example, show how to use data fusion method in the process of sensor model designing to get more robust output. Also we provide our idea on the relation of sensor model, data fusion and system structure, and in the paper, there is a solution that transform the parameter space to get linear model for Kalman filter.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supported by the Innovation Fund(No.CXJJ16M102)the National 973 Program of China (No.613192)
文摘High speed pseudorandom modulation and photon counting techniques are applied to a three-dimensional imaging lidar system.The specific structure and working principle of the lidar system is described.The actual detector efficiency of a single-photon detector in an imaging system is discussed,and the result shows that a variety of reasons lead to the decrease in detection efficiency.A series of ranging and imaging experiments are conducted,and a series of high-resolution three-dimensional images and a distance value of 1200 m of noncooperative targets are acquired.
基金the National Natural Science Foundation of China(grant No.51904088)Scientific Research Project of Colleges and Universities in Hebei Province(grant No.BJ2020042).
文摘In order to suppressing the particle deposition on vortex finder,a series of gas cyclones with the secondary swirling clean gas were developed inspired by the gas purge effect.Effects of the width and extension length of the flow channel as well as the secondary inlet velocity and running time on the particle deposition pattern,the deposited particle mass and the cyclones'performance were experimentally investigated,respectively.The results show that the ultrafine particles(Stokes number Stk<0.0358)are mainly loose deposited on the walls under the secondary gas.Compare to the conventional cyclone with single tangential inlet,the total deposited particle mass of the improved cyclone has a maximum reduction more than 60%,and the collecting efficiency is increased up to 97.5%under the basically same pressure drop.The corresponding no-deposition area is increased by about 13%,and remains constant in spite of extending the running time.Moreover,an interesting phenomenon named"self-cleaning effect"of the vortex finder was captured for the gas cyclones,and mechanism of the secondary clean gas on the particle deposition is preliminarily analyzed.The results can deepen the understanding of the particle deposition on the vortex finder and guide the design of the anti-coking gas cyclones.
基金Supported by CAS Knowledge Innovation Project(U-602,U-34)National Natural Science Foundation of China(10491300,10491303,10605030)100 Talents Program of CAS(U-25,U-54)
文摘We describe the algorithm to reconstruct the charged tracks for BESⅢ main drift chamber at BEPCⅡ, including the track finding and fitting. With a new method of the Track Segment Finder （TSF）, the results of present study indicate that the algorithm can reconstruct the charged tracks over a wide range of momentum with high efficiency, while improving the robustness against the background noise in the drift chamber. The overall performances, including spatial resolution, momentum resolution and secondary vertices reconstruction efficiency, etc. satisfy the requirements of BESⅢ experiment.
基金supported by the National Natural Science Foundation of China (Nos. 31771467, 31571360 and 31371291)
文摘Maize （Zea mays） is the most widely grown grain crop in the world, playing important roles in agriculture and industry. However, the functions of maize genes remain largely unknown. High-quality genome- wide transcriptome datasets provide important biological knowledge which has been widely and suc- cessfully used in plants not only by measuring gene expression levels but also by enabling co-expression analysis for predicting gene functions and modules related to agronomic traits. Recently, thousands of maize transcriptomic data are available across different inbred lines, development stages, tissues, and treatments, or even across different tissue sections and cell lines. Here, we integrated 701 transcriptomic and 108 epigenomic data and studied the different conditional networks with multi-dimensional omics levels. We constructed a searchable, integrative, one-stop online platform, the maize conditional co- expression network （MCENet） platform. MCENet provides 10 global/conditional co-expression net- works, 5 network accessional analysis toolkits （i.e., Network Search, Network Remodel, Module Finder, Network Comparison, and Dynamic Expression View） and multiple network functional support toolkits （e.g., motif and module enrichment analysis）. We hope that our database might help plant research communities to identify maize functional genes or modules that regulate important agronomic traits.
基金This work was supported by the National "863" Project (Grant No. 863-308-14-03(5))the National Natural Science Foundation of China (Grant No. 60178017).
文摘This note reports a new type of incoherent pulse laser Doppler lidar velocimeter with iodine molecular filter as a frequency discriminator. Its transmitter subsystem applies a Nd:YAG pulse laser which is injected with a single longitudinal-mode diode pumped continuous seeder laser. The field experiment proved that this velocimeter measurement results are consistent with those measured by photoelectric velocimeter. Measurements of eight different velocities show that the standard deviation is 0.56m/s, the range resolution is 3.75m.
基金co-supported by the National Natural Science Foundation of China,China(No.12272404)the Postgraduate Research Innovation Project of Hunan Province of China,China(No.CX20210016).
文摘Due to the portability and anti-interference ability,vision-based shipborne aircraft automatic landing systems have attracted the attention of researchers.In this paper,a Monocular Camera and Laser Range Finder(MC-LRF)-based pose measurement system is designed for shipborne aircraft automatic landing.First,the system represents the target ship using a set of sparse landmarks,and a two-stage model is adopted to detect landmarks on the target ship.The rough 6D pose is measured by solving a Perspective-n-Point problem.Then,once the rough pose is measured,a region-based pose refinement is used to continuously track the 6D pose in the subsequent image sequences.To address the low accuracy of monocular pose measurement in the depth direction,the designed system adopts a laser range finder to obtain an accurate range value.The measured rough pose is iteratively optimized using the accurate range measurement.Experimental results on synthetic and real images show that the system achieves robust and precise pose measurement of the target ship during automatic landing.The measurement means error is within 0.4in rotation,and 0.2%in translation,meeting the requirements for automatic fixed-wing aircraft landing.
基金National Natural Science Foundation of China(No.61603184)the Key Laboratory of Intelligent Perception and Systems for High-Dimensional Information(Nanjing University of Science and Technology),Ministry of Education,China(No.30920140122006)the Fundamental Research Funds for the Central Universities,China(No.30915011321)
文摘Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firstly, 2D sequential laser range finder data were aligned using a Dead-Reckoning （DR） and GPS loeaHzation method based on extended Kalman filter. Secondly, curb points were extracted from multi.frame laser data based on spatial-temporal correlation analysis. Finally. the straight and curved curbs were detected by coordinate axis conversion least square linear fitting method and piecewise weighted least square fitting model respectively. The proposed method can detect both raised and sunken curbs robustly in campus environment. The proposed method has been verified in a real robot platform.
文摘In this paper, we take the model of Laser range finder based on synchronized scanner as example, show how to use data fusion method in the process of sensor model designing to get more robust output. Also we provide our idea on the relation of sensor model, data fusion and system structure, and in the paper, there is a solution that transform the parameter space to get linear model for Kalman filter.
