As an independent navigation method,inertial navigation system(INS)has played a huge advantage in a lot of special conditions.But its positioning error will accumulate with time,so it is difficult to work independentl...As an independent navigation method,inertial navigation system(INS)has played a huge advantage in a lot of special conditions.But its positioning error will accumulate with time,so it is difficult to work independently for a long time.The vehicle loaded with the inertial navigation system usually drives on the road,so the high precision road data based on geographic information system(GIS)can be used as a bind of auxiliary information,which could correct INS errors by the correlation matching algorithm.The existing road matching methods rely on mathematical models,mostly for global positioning system(GPS)trajectory data,and are limited to model parameters.Therefore,based on the features of inertial navigation trajectory and road,this paper proposes a road data aided vehicle inertial navigation method based on the learning to rank and iterative closest contour point(ICCP)algorithm.Firstly,according to the geometric and directional features of inertial navigation trajectory and road,the combined feature vector is constructed as the input value;Furthermore,the scoring function and RankNet neural network based on the features of vehicle trajectory data and road data are constructed,which can learn and extract the features;Then,the nearest point of each track point and its corresponding road data set to be matched is calculated.The average translation between the two data sets is calculated by using the position relationship between each group of track points to be matched and road points;Finally,the trajectory data set is iteratively translated according to the translation amount,and the matching track point set is obtained when the trajectory error converges to complete the matching.During experiments,it is compared with other algorithms including the hidden Markov model(HMM)matching method.The experimental results show that the algorithm can effectively suppress the divergence of trajectory error.The matching accuracy is close to HMM algorithm,and the computational efficiency can meet the requirements of the traditional matching algorithm.展开更多
Land public transport is an important link within and between cities,and how to control the transmission of COVID-19 in land public transport is a critical issue in our daily lives.However,there are still many inconsi...Land public transport is an important link within and between cities,and how to control the transmission of COVID-19 in land public transport is a critical issue in our daily lives.However,there are still many inconsistent opinions and views about the spread of SARS-CoV-2 in land public transport,which limits our ability to implement effective interventions.The purpose of this review is to overview the literature on transmission characteristics and routes of the epidemic in land public transport,as well as to investigate factors affecting its spread and provide feasible measures to mitigate the infection risk of passengers.We obtained 898 papers by searching the Web of Science,Pubmed,and WHO global COVID database by keywords,and finally selected 45 papers that can address the purpose of this review.Land public transport is a high outbreak area for COVID-19 due to characteristics like crowding,inadequate ventilation,long exposure time,and environmental closure.Different from surface touch transmission and drop spray transmission,aerosol inhalation transmission can occur not only in short distances but also in long distances.Insufficient ventilation is the most important factor influencing long-distance aerosol transmission.Other transmission factors(e.g.,interpersonal distance,relative orientation,and ambient conditions)should be noticed as well,which have been summarized in this paper.To address various influencing factors,it is essential to suggest practical and efficient preventive measures.Among these,increased ventilation,particularly the fresh air(i.e.,natural ventilation),has proven to effectively reduce indoor infection risk.Many preventive measures are also effective,such as enlarging social distance,avoiding face-to-face orientation,setting up physical partitions,disinfection,avoiding talking,and so on.As research on the epidemic has intensified,people have broken down many perceived barriers,but more comprehensive studies on monitoring systems and prevention measures in land public transport are still needed.展开更多
Ultrasound-assisted synthesis of Mn/Co-MOF nanomaterial was used to capture uranium from aqueous solutions. Tests of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infr...Ultrasound-assisted synthesis of Mn/Co-MOF nanomaterial was used to capture uranium from aqueous solutions. Tests of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared spectra (FT-IR), Zeta potential analysis, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) suggest that cobalt ions were replaced partially by manganese ions to generate MOF during the synthesis process and form manganous oxide particles loaded on the surface of Mn/Co-MOF. The optimal immobilization conditions of U(VI) were systematically studied by solution pH, kinetic, contact time and preparatory uranium concentration. XPS spectroscopy analysis indicated that the chelation of imidazole ring to uranium and Mn3O4 possibly played a certain role in the adsorption process. The results indicate that the adsorption isotherms of the Mn/Co-MOF for uranium suit Langmuir isotherm model (maximum adsorption capacity were 763.36 mg/g). Furthermore, the adsorption kinetics of Mn/Co-MOF match comfortably with the pseudo-second-order kinetic model.展开更多
基金National Key Research and Development Plan(2016YFB0502300)。
文摘As an independent navigation method,inertial navigation system(INS)has played a huge advantage in a lot of special conditions.But its positioning error will accumulate with time,so it is difficult to work independently for a long time.The vehicle loaded with the inertial navigation system usually drives on the road,so the high precision road data based on geographic information system(GIS)can be used as a bind of auxiliary information,which could correct INS errors by the correlation matching algorithm.The existing road matching methods rely on mathematical models,mostly for global positioning system(GPS)trajectory data,and are limited to model parameters.Therefore,based on the features of inertial navigation trajectory and road,this paper proposes a road data aided vehicle inertial navigation method based on the learning to rank and iterative closest contour point(ICCP)algorithm.Firstly,according to the geometric and directional features of inertial navigation trajectory and road,the combined feature vector is constructed as the input value;Furthermore,the scoring function and RankNet neural network based on the features of vehicle trajectory data and road data are constructed,which can learn and extract the features;Then,the nearest point of each track point and its corresponding road data set to be matched is calculated.The average translation between the two data sets is calculated by using the position relationship between each group of track points to be matched and road points;Finally,the trajectory data set is iteratively translated according to the translation amount,and the matching track point set is obtained when the trajectory error converges to complete the matching.During experiments,it is compared with other algorithms including the hidden Markov model(HMM)matching method.The experimental results show that the algorithm can effectively suppress the divergence of trajectory error.The matching accuracy is close to HMM algorithm,and the computational efficiency can meet the requirements of the traditional matching algorithm.
基金supported by the National Natural Science Foundation of China(42175095,41875015,42005069 and 42175180)support from Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004,2021B0301030007)+1 种基金the UK GCRF Rapid Resp0nse Grant on‘Transmission of SARS-CoV-2 virus in crowded indoor environment'the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311020001)。
文摘Land public transport is an important link within and between cities,and how to control the transmission of COVID-19 in land public transport is a critical issue in our daily lives.However,there are still many inconsistent opinions and views about the spread of SARS-CoV-2 in land public transport,which limits our ability to implement effective interventions.The purpose of this review is to overview the literature on transmission characteristics and routes of the epidemic in land public transport,as well as to investigate factors affecting its spread and provide feasible measures to mitigate the infection risk of passengers.We obtained 898 papers by searching the Web of Science,Pubmed,and WHO global COVID database by keywords,and finally selected 45 papers that can address the purpose of this review.Land public transport is a high outbreak area for COVID-19 due to characteristics like crowding,inadequate ventilation,long exposure time,and environmental closure.Different from surface touch transmission and drop spray transmission,aerosol inhalation transmission can occur not only in short distances but also in long distances.Insufficient ventilation is the most important factor influencing long-distance aerosol transmission.Other transmission factors(e.g.,interpersonal distance,relative orientation,and ambient conditions)should be noticed as well,which have been summarized in this paper.To address various influencing factors,it is essential to suggest practical and efficient preventive measures.Among these,increased ventilation,particularly the fresh air(i.e.,natural ventilation),has proven to effectively reduce indoor infection risk.Many preventive measures are also effective,such as enlarging social distance,avoiding face-to-face orientation,setting up physical partitions,disinfection,avoiding talking,and so on.As research on the epidemic has intensified,people have broken down many perceived barriers,but more comprehensive studies on monitoring systems and prevention measures in land public transport are still needed.
基金supported by the National Natural Science Foundation of China(grant No.21866005)Jiangxi Key Plan of Research and Development(grant No.20192BBH80011).
文摘Ultrasound-assisted synthesis of Mn/Co-MOF nanomaterial was used to capture uranium from aqueous solutions. Tests of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared spectra (FT-IR), Zeta potential analysis, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) suggest that cobalt ions were replaced partially by manganese ions to generate MOF during the synthesis process and form manganous oxide particles loaded on the surface of Mn/Co-MOF. The optimal immobilization conditions of U(VI) were systematically studied by solution pH, kinetic, contact time and preparatory uranium concentration. XPS spectroscopy analysis indicated that the chelation of imidazole ring to uranium and Mn3O4 possibly played a certain role in the adsorption process. The results indicate that the adsorption isotherms of the Mn/Co-MOF for uranium suit Langmuir isotherm model (maximum adsorption capacity were 763.36 mg/g). Furthermore, the adsorption kinetics of Mn/Co-MOF match comfortably with the pseudo-second-order kinetic model.
