We installed two sets of Astronomical Site Monitoring Systems(ASMSs)at Lijiang Observatory(GMG),for the running of the 2.4-meter Lijiang optical telescope(LJT)and the 1.6-meter Multi-channel Photometric Survey Telesco...We installed two sets of Astronomical Site Monitoring Systems(ASMSs)at Lijiang Observatory(GMG),for the running of the 2.4-meter Lijiang optical telescope(LJT)and the 1.6-meter Multi-channel Photometric Survey Telescope(Mephisto).The Mephisto is under construction.The ASMS has been running on robotic mode since 2017.The core instruments:Cloud Sensor,All-Sky Camera and AutonomousDIMM that are developed by our group,together with the commercial Meteorological Station and Sky Quality Meter,are combined into the astronomical optical site monitoring system.The new Cloud Sensor's Cloud-Clear Relationship is presented for the first time,which is used to calculate the All-Sky cloud cover.We designed the Autonomous-DIMM located on a tower,with the same height as LJT.The seeing data have been observed for a full year.ASMS's data for the year 2019 are also analysed in detail,which are valuable to observers.展开更多
The water quality grades of phosphate（PO4-P） and dissolved inorganic nitrogen（DIN） are integrated by spatial partitioning to fit the global and local semi-variograms of these nutrients. Leave-one-out cross validat...The water quality grades of phosphate（PO4-P） and dissolved inorganic nitrogen（DIN） are integrated by spatial partitioning to fit the global and local semi-variograms of these nutrients. Leave-one-out cross validation is used to determine the statistical inference method. To minimize absolute average errors and error mean squares,stratified Kriging（SK） interpolation is applied to DIN and ordinary Kriging（OK） interpolation is applied to PO4-P.Ten percent of the sites is adjusted by considering their impact on the change in deviations in DIN and PO4-P interpolation and the resultant effect on areas with different water quality grades. Thus, seven redundant historical sites are removed. Seven historical sites are distributed in areas with water quality poorer than Grade IV at the north and south branches of the Changjiang（Yangtze River） Estuary and at the coastal region north of the Hangzhou Bay. Numerous sites are installed in these regions. The contents of various elements in the waters are not remarkably changed, and the waters are mixed well. Seven sites that have been optimized and removed are set to water with quality Grades III and IV. Optimization and adjustment of unrestricted areas show that the optimized and adjusted sites are mainly distributed in regions where the water quality grade undergoes transition.Therefore, key sites for adjustment and optimization are located at the boundaries of areas with different water quality grades and seawater.展开更多
In this paper, we analyze the time series of site coordinates of 27 continuously monitoring GPS sites covered by the Crustal Movement Observation Network of China over the whole country. The data are obtained in the p...In this paper, we analyze the time series of site coordinates of 27 continuously monitoring GPS sites covered by the Crustal Movement Observation Network of China over the whole country. The data are obtained in the period from the beginning of the observation to the November of 2005. On the basis of data processing, we analyze the power spectrum density of coordinate component noise at each site and calculate the spectral indexes manifesting the noise property of each component. The spectral indexes indicate that for most sites, the noise of time series of each coordinate component can be addressed by the model of white noise ＋ flicker noise; and for a small amount of sites, it can be described by the model of white noise ＋ flicker noise ＋ random walk noise. We also quantitatively estimate each noise component in the model by using the criterion of maximum likelihood estimation. The result shows that the white noise in the time series of GPS site coordinates does not constitute the main part of noise. Therefore, the error estimation of site movement parameters is usually too small, or too optimistic if we consider the white noise only. Correspondingly, if this factor is not fully considered in explaining these movement parameters, it might mislead the readers.展开更多
In the current rapid development of China's environmental protection cause, the construction and control work of environmental protection projects in various parts of the country are becoming more and stricter. Th...In the current rapid development of China's environmental protection cause, the construction and control work of environmental protection projects in various parts of the country are becoming more and stricter. Through the air monitoring of environmental protection projects, the actual operation value of environmental protection project construction can be well improved. However, there are still many external influencing factors in the field work of air monitoring, which have a negative impact on the quality of the overall monitoring work. Therefore, it is necessary to actively do a good job in the air monitoring of environmental protection projects. So as to ensure that the results of air monitoring can reflect the actual conditions of the atmosphere in the region, actively carry out the air monitoring and control work of environmental protection projects, enable the air monitoring work to be carried out to the maximum extent, and provide more help for the value of environmental projects. However, in the current air monitoring work of environmental protection projects, there are various problems, which have brought serious adverse effects to the overall air monitoring work of the project. Therefore, it is necessary to pay attention to the attention of relevant quality control staff, and to improve the quality of the air monitoring site of environmental protection projects.展开更多
Aiming to get the strata behavior and stability rules of surrounding rock of the main return airway of Yushujing Coal Mine, convergence deformation of two sides and force of U-shaped steel yieldable support and bolt w...Aiming to get the strata behavior and stability rules of surrounding rock of the main return airway of Yushujing Coal Mine, convergence deformation of two sides and force of U-shaped steel yieldable support and bolt were monitored, and deformation of surrounding rock and mechanical characteristics of support structure were timely obtained to guide the informa- tion construction and optimize supporting parameters in water-rich soft rock roadway. The field monitoring results indicate the following. （1） Convergence displacement of rock surface increases with time continuity and shows surrounding rock＇s intense theological behavior. The original support scheme cannot control the large deformation and strongly theological behavior; （2） Without backfilling, the U-shaped steel support begins to bear load after erecting for 4-7 days and increases rapidly in the first 30 days. The U-shaped steel support at the right shoulder and top of roadway bears a larger force and the left side and shoulder bears a smaller force; （3） The stress of bolt increasing over time and at the right shoulder of roadway has larger growth and value. The mechanism of rock deformation and the failure and strata behavior in water-rich soft rock roadway are revealed based on the results of the measured relaxation zone of surrounding rock, measured stresses, and the rock mechanics tests.展开更多
Optical and Synthetic Aperture Radar(SAR)remote sensing has a long history of use and reached a good level of maturity in archaeological and cultural heritage applications,yet further advances are viable through the e...Optical and Synthetic Aperture Radar(SAR)remote sensing has a long history of use and reached a good level of maturity in archaeological and cultural heritage applications,yet further advances are viable through the exploitation of novel sensor data and imaging modes,big data and high-performance computing,advanced and automated analysis methods.This paper showcases the main research avenues in this field,with a focus on archaeological prospection and heritage site protection.Six demonstration use-cases with a wealth of heritage asset types(e.g.excavated and still buried archaeological features,standing monuments,natural reserves,burial mounds,paleo-channels)and respective scientific research objectives are presented:the Ostia-Portus area and the wider Province of Rome(Italy),the city of Wuhan and the Jiuzhaigou National Park(China),and the Siberian“Valley of the Kings”(Russia).Input data encompass both archive and newly tasked medium to very high-resolution imagery acquired over the last decade from satellite(e.g.Copernicus Sentinels and ESA Third Party Missions)and aerial(e.g.Unmanned Aerial Vehicles,UAV)platforms,as well as field-based evidence and ground truth,auxiliary topographic data,Digital Elevation Models(DEM),and monitoring data from geodetic campaigns and networks.The novel results achieved for the use-cases contribute to the discussion on the advantages and limitations of optical and SAR-based archaeological and heritage applications aimed to detect buried and sub-surface archaeological assets across rural and semi-vegetated landscapes,identify threats to cultural heritage assets due to ground instability and urban development in large metropolises,and monitor post-disaster impacts in natural reserves.展开更多
With the ecological environment problem becoming more and more serious, it poses a great threat to human existence. The environmental monitoring work should be further strengthened to scientifically evaluate the envir...With the ecological environment problem becoming more and more serious, it poses a great threat to human existence. The environmental monitoring work should be further strengthened to scientifically evaluate the environmental pollution problems, so as to provide a basis for formulating more scientific and effective environmental governance and maintenance strategies. Field sampling is one of the important links in environmental monitoring and is an important basis for environmental monitoring and evaluation. Through the comprehensive analysis of the quality influencing factors of environmental monitoring field sampling, strengthening the quality control of field sampling can provide a more realistic and effective reference basis for environmental monitoring and strengthen the effect of environmental monitoring.展开更多
Underground mining activities and rainfall have potential important influence on the initiation and reactivation of the slope deformations,especially on the steep rock slope. In this paper,using the discrete element m...Underground mining activities and rainfall have potential important influence on the initiation and reactivation of the slope deformations,especially on the steep rock slope. In this paper,using the discrete element method(UDEC),numerical simulation was carried out to investigate deformation features and the failure mechanism of the steep rock slope under mining activities and rainfall. A steep rock slope numerical model was created based on a case study at the Wulong area in Chongqing city,China. Mechanical parameters of the rock mass have been determined by situ measurements and laboratory measurements. A preliminary site monitoring system has been realized,aiming at getting structure movements and stresses of unstablerock masses at the most significant discontinuities. According to the numerical model calibrated based on the monitoring data,four types of operation conditions are designed to reveal the effect of mining excavation and extreme rainfall on the deformation of the steep rock slope.展开更多
In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtain...In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtains the deformation characteristics and change rules of the occluded pile by measuring the strain and displacement of the pile body. The research conclusion can provide a certain reference value for the pile body design of bite pile in similar projects.展开更多
Earthwork productivity analysis is essential for successful construction projects.If productivity analysis results can be accessed anytime and anywhere,then project management can be performed more efficiently.To this...Earthwork productivity analysis is essential for successful construction projects.If productivity analysis results can be accessed anytime and anywhere,then project management can be performed more efficiently.To this end,this paper proposes an earthwork productivity monitoring framework via a real-time scene updating multi-vision platform.The framework consists of four main processes:1)site-optimized database development;2)real-time monitoring model updating;3)multi-vision productivity monitoring;and 4)web-based monitoring platform for Internetconnected devices.The experimental results demonstrated satisfactory performance,with an average macro F1-score of 87.3%for continuous site-specific monitoring,an average accuracy of 86.2%for activity recognition,and the successful operation of multi-vision productivity monitoring through a web-based platform in real time.The findings can contribute to supporting site managers to understand real-time earthmoving operations while achieving better construction project and information management.展开更多
The data of cultivated land quality monitoring sites,and the current situations and evolution trend of soil organic matter in cultivated land in Northeast China were analyzed.Then,the causes for low organic matter con...The data of cultivated land quality monitoring sites,and the current situations and evolution trend of soil organic matter in cultivated land in Northeast China were analyzed.Then,the causes for low organic matter content were discussed.Finally,it came up with pertinent soil improvement recommendations,including actively promoting the quality protection technology model of cultivated land such as straw returning in accordance with local conditions,expanding organic fertilizer sources and increasing application of organic fertilizers,implementing reasonable crop rotation,planting green manure crops such as legumes,and realizing the combination of land use and land cultivation,establishing a reasonable fertilization system,combining organic and inorganic fertilizers with scientific fertilization,increasing fertilizer efficiency and reducing the application of chemical fertilizers,increasing financial investment and promoting the integration of funds related to cultivated land protection.展开更多
An imported energy spectrum analyzer is powerful, but English operation interface is not easy to use. According to actual work needs, preliminary design of the Chinese energy spectrum analysis system is introduced in ...An imported energy spectrum analyzer is powerful, but English operation interface is not easy to use. According to actual work needs, preliminary design of the Chinese energy spectrum analysis system is introduced in the paper.展开更多
A new form of producing and sharing knowledge has emerged as an international(United States of America,Asia,and Europe) research collaboration,known as the Long-Term Ecological Research(LTER) Network.Although Africa b...A new form of producing and sharing knowledge has emerged as an international(United States of America,Asia,and Europe) research collaboration,known as the Long-Term Ecological Research(LTER) Network.Although Africa boasts rich biodiversity,including endemic species,it lacks the long-term initiatives to underpin sustainable biodiversity managements.At present,climate change may exacerbate hunger and poverty concerns in addition to resulting in ecosystem degradation,land use change,and other threats in Africa.Therefore,ecosystem monitoring was suggested to understanding the effects of climate change and setting strategies to mitigate these changes.This paper aimed to investigate ecosystem monitoring ground sites and address their coverage gaps in Africa to provide a foundation for optimizing the African Ecosystem Research Network(AERN) ground sites.The geographic coordinates and characteristics of ground sites-based ecosystem monitoring were collected from various networks aligned with the LTER implementation in Africa.Additionally,climatic data and biodiversity distribution maps were retrieved from various sources.These data were used to assess the size of existing ground sites and the gaps in description,ecosystems and biomes.The results reveal that there were 1089 sites established by various networks.Among these sites,30.5%,27.5%,and 28.8% had no information of area,year of establishment,current status,respectively.However,68.0% of them had an area equal to or greater than 1 km2.Sites were created progressively over the course of the years,with 68.9% being created from 2000 to 2005.To date,only 41.5% of the sites were operational.The sites were scattered across Africa,but they were concentrated in Eastern and Southern Africa.The unbalanced distribution pattern of the sites left Central and Northern Africa hardly covered,and many unique ecosystems in Central Africa were not included.To sustain these sites,the AERN should be based on operational sites,seeking secure funding by establishing multiple partnerships.展开更多
A circular shaft is often used to access a working well for deep underground space utilization.As the depth of underground space increases,the excavation depth of the shaft increases.In this study,the deformation char...A circular shaft is often used to access a working well for deep underground space utilization.As the depth of underground space increases,the excavation depth of the shaft increases.In this study,the deformation characteristics of a circular shaft with a depth of 56.3 m were presented and analysed.The main monitoring contents included:(1)wall deflection;(2)vertical wall movement;(3)horizontal soil movement;(4)vertical surface movement;and(5)basal heave.Horizontally,the maximum wall deflection was only 7.7 mm.Compared with the wall deflection data collected for another 29 circular excavations,the ratio of maximum wall deflection to excavation depth of this shaft was smaller due to a smaller ratio of diameter to excavation depth.The wall deflection underwent two stages of deformation:the first stage was mainly circumferential compression caused by the mutual extrusion of joints between walls,and the second stage was typical vertical deflection deformation.The horizontal soil movement outside the shaft was greater than the wall deflection and the deep soil caused great horizontal movement because of dewatering at confined water layers.Vertically,a basal heave of 203.8 mm occurred in the pit centre near the bottom.Meanwhile,the shaft was uplifted over time and showed 3 stages of vertical movement.The surface outside the shaft exhibited settlement and uplift deformation at different locations due to different effects.The basal heave caused by excavation was the dominant factor,driving the vertical movement of the shaft as well as the surrounding surface.The correlation between the wall deflection and the surface settlement outside the shaft was weak.展开更多
基金the National Natural Science Foundation of China(NSFC,Grant Nos.11991051,11203073,11573067,11873092 and 11803087)the CAS“Light of West China”Program(No.Y8XB018001)。
文摘We installed two sets of Astronomical Site Monitoring Systems(ASMSs)at Lijiang Observatory(GMG),for the running of the 2.4-meter Lijiang optical telescope(LJT)and the 1.6-meter Multi-channel Photometric Survey Telescope(Mephisto).The Mephisto is under construction.The ASMS has been running on robotic mode since 2017.The core instruments:Cloud Sensor,All-Sky Camera and AutonomousDIMM that are developed by our group,together with the commercial Meteorological Station and Sky Quality Meter,are combined into the astronomical optical site monitoring system.The new Cloud Sensor's Cloud-Clear Relationship is presented for the first time,which is used to calculate the All-Sky cloud cover.We designed the Autonomous-DIMM located on a tower,with the same height as LJT.The seeing data have been observed for a full year.ASMS's data for the year 2019 are also analysed in detail,which are valuable to observers.
基金The National Natural Science Fundation of China under contract Nos 41376190,41271404,41531179,41421001 and41601425the Open Funds of the Key Laboratory of Integrated Monitoring and Applied Technologies for Marin Harmful Algal Blooms,SOA under contract No.MATHA201120204+1 种基金the Scientific Research Project of Shanghai Marine Bureau under contract No.Hu Hai Ke2016-05the Ocean Public Welfare Scientific Research Project,State Oceanic Administration of the People's Republic of China under contract Nos 201305027 and 201505008
文摘The water quality grades of phosphate（PO4-P） and dissolved inorganic nitrogen（DIN） are integrated by spatial partitioning to fit the global and local semi-variograms of these nutrients. Leave-one-out cross validation is used to determine the statistical inference method. To minimize absolute average errors and error mean squares,stratified Kriging（SK） interpolation is applied to DIN and ordinary Kriging（OK） interpolation is applied to PO4-P.Ten percent of the sites is adjusted by considering their impact on the change in deviations in DIN and PO4-P interpolation and the resultant effect on areas with different water quality grades. Thus, seven redundant historical sites are removed. Seven historical sites are distributed in areas with water quality poorer than Grade IV at the north and south branches of the Changjiang（Yangtze River） Estuary and at the coastal region north of the Hangzhou Bay. Numerous sites are installed in these regions. The contents of various elements in the waters are not remarkably changed, and the waters are mixed well. Seven sites that have been optimized and removed are set to water with quality Grades III and IV. Optimization and adjustment of unrestricted areas show that the optimized and adjusted sites are mainly distributed in regions where the water quality grade undergoes transition.Therefore, key sites for adjustment and optimization are located at the boundaries of areas with different water quality grades and seawater.
基金Special project of China Earthquake Administration"Study on the Integrated Observation of Vertical Crustal Move-ment and Deformation of South-North Seismic Zone on the Chinese Mainland".
文摘In this paper, we analyze the time series of site coordinates of 27 continuously monitoring GPS sites covered by the Crustal Movement Observation Network of China over the whole country. The data are obtained in the period from the beginning of the observation to the November of 2005. On the basis of data processing, we analyze the power spectrum density of coordinate component noise at each site and calculate the spectral indexes manifesting the noise property of each component. The spectral indexes indicate that for most sites, the noise of time series of each coordinate component can be addressed by the model of white noise ＋ flicker noise; and for a small amount of sites, it can be described by the model of white noise ＋ flicker noise ＋ random walk noise. We also quantitatively estimate each noise component in the model by using the criterion of maximum likelihood estimation. The result shows that the white noise in the time series of GPS site coordinates does not constitute the main part of noise. Therefore, the error estimation of site movement parameters is usually too small, or too optimistic if we consider the white noise only. Correspondingly, if this factor is not fully considered in explaining these movement parameters, it might mislead the readers.
文摘In the current rapid development of China's environmental protection cause, the construction and control work of environmental protection projects in various parts of the country are becoming more and stricter. Through the air monitoring of environmental protection projects, the actual operation value of environmental protection project construction can be well improved. However, there are still many external influencing factors in the field work of air monitoring, which have a negative impact on the quality of the overall monitoring work. Therefore, it is necessary to actively do a good job in the air monitoring of environmental protection projects. So as to ensure that the results of air monitoring can reflect the actual conditions of the atmosphere in the region, actively carry out the air monitoring and control work of environmental protection projects, enable the air monitoring work to be carried out to the maximum extent, and provide more help for the value of environmental projects. However, in the current air monitoring work of environmental protection projects, there are various problems, which have brought serious adverse effects to the overall air monitoring work of the project. Therefore, it is necessary to pay attention to the attention of relevant quality control staff, and to improve the quality of the air monitoring site of environmental protection projects.
基金Supported by the Projects of National Natural Science Foundation （51174196） the Program for New Century Excellent Talents in University （NCET-07-0519）
文摘Aiming to get the strata behavior and stability rules of surrounding rock of the main return airway of Yushujing Coal Mine, convergence deformation of two sides and force of U-shaped steel yieldable support and bolt were monitored, and deformation of surrounding rock and mechanical characteristics of support structure were timely obtained to guide the informa- tion construction and optimize supporting parameters in water-rich soft rock roadway. The field monitoring results indicate the following. （1） Convergence displacement of rock surface increases with time continuity and shows surrounding rock＇s intense theological behavior. The original support scheme cannot control the large deformation and strongly theological behavior; （2） Without backfilling, the U-shaped steel support begins to bear load after erecting for 4-7 days and increases rapidly in the first 30 days. The U-shaped steel support at the right shoulder and top of roadway bears a larger force and the left side and shoulder bears a smaller force; （3） The stress of bolt increasing over time and at the right shoulder of roadway has larger growth and value. The mechanism of rock deformation and the failure and strata behavior in water-rich soft rock roadway are revealed based on the results of the measured relaxation zone of surrounding rock, measured stresses, and the rock mechanics tests.
基金supported by the European Space Agency(ESA)and the National Remote Sensing Center(NRSCC)-Ministry of Science and Technology(MOST)of the P.R.China under[grant number 58113]ESA[contract number 4000135360/21/I-NB,grant numbers 190791 and PP0085498]+3 种基金the German Aerospace Center(DLR)[grant number MTH3764]the Italian Space Agency(ASI)[COSMO-SkyMed license WUHAN-CSK]Planet Labs PBC under the Education and Research Program[grant number 412519]the National Natural Science Foundation of China[grant number 42250610212].
文摘Optical and Synthetic Aperture Radar(SAR)remote sensing has a long history of use and reached a good level of maturity in archaeological and cultural heritage applications,yet further advances are viable through the exploitation of novel sensor data and imaging modes,big data and high-performance computing,advanced and automated analysis methods.This paper showcases the main research avenues in this field,with a focus on archaeological prospection and heritage site protection.Six demonstration use-cases with a wealth of heritage asset types(e.g.excavated and still buried archaeological features,standing monuments,natural reserves,burial mounds,paleo-channels)and respective scientific research objectives are presented:the Ostia-Portus area and the wider Province of Rome(Italy),the city of Wuhan and the Jiuzhaigou National Park(China),and the Siberian“Valley of the Kings”(Russia).Input data encompass both archive and newly tasked medium to very high-resolution imagery acquired over the last decade from satellite(e.g.Copernicus Sentinels and ESA Third Party Missions)and aerial(e.g.Unmanned Aerial Vehicles,UAV)platforms,as well as field-based evidence and ground truth,auxiliary topographic data,Digital Elevation Models(DEM),and monitoring data from geodetic campaigns and networks.The novel results achieved for the use-cases contribute to the discussion on the advantages and limitations of optical and SAR-based archaeological and heritage applications aimed to detect buried and sub-surface archaeological assets across rural and semi-vegetated landscapes,identify threats to cultural heritage assets due to ground instability and urban development in large metropolises,and monitor post-disaster impacts in natural reserves.
文摘With the ecological environment problem becoming more and more serious, it poses a great threat to human existence. The environmental monitoring work should be further strengthened to scientifically evaluate the environmental pollution problems, so as to provide a basis for formulating more scientific and effective environmental governance and maintenance strategies. Field sampling is one of the important links in environmental monitoring and is an important basis for environmental monitoring and evaluation. Through the comprehensive analysis of the quality influencing factors of environmental monitoring field sampling, strengthening the quality control of field sampling can provide a more realistic and effective reference basis for environmental monitoring and strengthen the effect of environmental monitoring.
基金financially supported by a grant from China Natural Science foundation (51379112,51422904)the National Program on Key Basic Research Project of China (973 Program)(2013CB036002)the National Natural Science Foundation of China (51309144)
文摘Underground mining activities and rainfall have potential important influence on the initiation and reactivation of the slope deformations,especially on the steep rock slope. In this paper,using the discrete element method(UDEC),numerical simulation was carried out to investigate deformation features and the failure mechanism of the steep rock slope under mining activities and rainfall. A steep rock slope numerical model was created based on a case study at the Wulong area in Chongqing city,China. Mechanical parameters of the rock mass have been determined by situ measurements and laboratory measurements. A preliminary site monitoring system has been realized,aiming at getting structure movements and stresses of unstablerock masses at the most significant discontinuities. According to the numerical model calibrated based on the monitoring data,four types of operation conditions are designed to reveal the effect of mining excavation and extreme rainfall on the deformation of the steep rock slope.
文摘In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtains the deformation characteristics and change rules of the occluded pile by measuring the strain and displacement of the pile body. The research conclusion can provide a certain reference value for the pile body design of bite pile in similar projects.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Nos.RS-2023-00241758,2021R1A2C2003696,and RS-2024-00334513).
文摘Earthwork productivity analysis is essential for successful construction projects.If productivity analysis results can be accessed anytime and anywhere,then project management can be performed more efficiently.To this end,this paper proposes an earthwork productivity monitoring framework via a real-time scene updating multi-vision platform.The framework consists of four main processes:1)site-optimized database development;2)real-time monitoring model updating;3)multi-vision productivity monitoring;and 4)web-based monitoring platform for Internetconnected devices.The experimental results demonstrated satisfactory performance,with an average macro F1-score of 87.3%for continuous site-specific monitoring,an average accuracy of 86.2%for activity recognition,and the successful operation of multi-vision productivity monitoring through a web-based platform in real time.The findings can contribute to supporting site managers to understand real-time earthmoving operations while achieving better construction project and information management.
文摘The data of cultivated land quality monitoring sites,and the current situations and evolution trend of soil organic matter in cultivated land in Northeast China were analyzed.Then,the causes for low organic matter content were discussed.Finally,it came up with pertinent soil improvement recommendations,including actively promoting the quality protection technology model of cultivated land such as straw returning in accordance with local conditions,expanding organic fertilizer sources and increasing application of organic fertilizers,implementing reasonable crop rotation,planting green manure crops such as legumes,and realizing the combination of land use and land cultivation,establishing a reasonable fertilization system,combining organic and inorganic fertilizers with scientific fertilization,increasing fertilizer efficiency and reducing the application of chemical fertilizers,increasing financial investment and promoting the integration of funds related to cultivated land protection.
文摘An imported energy spectrum analyzer is powerful, but English operation interface is not easy to use. According to actual work needs, preliminary design of the Chinese energy spectrum analysis system is introduced in the paper.
基金Under the auspices of National Natural Science Foundation of China(No.31161140355)
文摘A new form of producing and sharing knowledge has emerged as an international(United States of America,Asia,and Europe) research collaboration,known as the Long-Term Ecological Research(LTER) Network.Although Africa boasts rich biodiversity,including endemic species,it lacks the long-term initiatives to underpin sustainable biodiversity managements.At present,climate change may exacerbate hunger and poverty concerns in addition to resulting in ecosystem degradation,land use change,and other threats in Africa.Therefore,ecosystem monitoring was suggested to understanding the effects of climate change and setting strategies to mitigate these changes.This paper aimed to investigate ecosystem monitoring ground sites and address their coverage gaps in Africa to provide a foundation for optimizing the African Ecosystem Research Network(AERN) ground sites.The geographic coordinates and characteristics of ground sites-based ecosystem monitoring were collected from various networks aligned with the LTER implementation in Africa.Additionally,climatic data and biodiversity distribution maps were retrieved from various sources.These data were used to assess the size of existing ground sites and the gaps in description,ecosystems and biomes.The results reveal that there were 1089 sites established by various networks.Among these sites,30.5%,27.5%,and 28.8% had no information of area,year of establishment,current status,respectively.However,68.0% of them had an area equal to or greater than 1 km2.Sites were created progressively over the course of the years,with 68.9% being created from 2000 to 2005.To date,only 41.5% of the sites were operational.The sites were scattered across Africa,but they were concentrated in Eastern and Southern Africa.The unbalanced distribution pattern of the sites left Central and Northern Africa hardly covered,and many unique ecosystems in Central Africa were not included.To sustain these sites,the AERN should be based on operational sites,seeking secure funding by establishing multiple partnerships.
基金the National Natural Science Foundation of China(Grant No.52090083)Shanghai Chenguang Program(Grant No.20CG26)Consulting project on Shanghai deep tunnel project.
文摘A circular shaft is often used to access a working well for deep underground space utilization.As the depth of underground space increases,the excavation depth of the shaft increases.In this study,the deformation characteristics of a circular shaft with a depth of 56.3 m were presented and analysed.The main monitoring contents included:(1)wall deflection;(2)vertical wall movement;(3)horizontal soil movement;(4)vertical surface movement;and(5)basal heave.Horizontally,the maximum wall deflection was only 7.7 mm.Compared with the wall deflection data collected for another 29 circular excavations,the ratio of maximum wall deflection to excavation depth of this shaft was smaller due to a smaller ratio of diameter to excavation depth.The wall deflection underwent two stages of deformation:the first stage was mainly circumferential compression caused by the mutual extrusion of joints between walls,and the second stage was typical vertical deflection deformation.The horizontal soil movement outside the shaft was greater than the wall deflection and the deep soil caused great horizontal movement because of dewatering at confined water layers.Vertically,a basal heave of 203.8 mm occurred in the pit centre near the bottom.Meanwhile,the shaft was uplifted over time and showed 3 stages of vertical movement.The surface outside the shaft exhibited settlement and uplift deformation at different locations due to different effects.The basal heave caused by excavation was the dominant factor,driving the vertical movement of the shaft as well as the surrounding surface.The correlation between the wall deflection and the surface settlement outside the shaft was weak.
