After the fabrication of magnetic resonance superconducting magnets,the magnetic field inhomogeneity needs to be accurately measured for subsequent shimming.However,conventional measurement methods are susceptible to ...After the fabrication of magnetic resonance superconducting magnets,the magnetic field inhomogeneity needs to be accurately measured for subsequent shimming.However,conventional measurement methods are susceptible to magnetic fields,have poor compatibility,and are difficult to adapt to various types of magnets.This paper proposes a new field measuring system based on a three-axis movable platform.The system utilizes non-magnetic materials and an innovative hand-wheel lifting design that can be adapted to various aperture magnets,thus obviating the necessity for electrically driven equipment and addressing safety concerns in strong magnetic fields.In addition,the measurement system offers high accuracy up to 1 mm and a wide measurable range.The fields of 3 T and 7 T magnets were mapped using the designed system with diameter of spherical volume(DSV)of 160 mm and 130 mm,respectively.Experimental results demonstrate that the magnetic field measurement system has strong compatibility and can accurately map the magnetic field at arbitrary positions,which is critical for shimming studies.展开更多
The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambr...The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambra Basin between latitudes 6˚43'N and 6˚47'N and longitudes 7˚28'E and 7˚32'E, it is stratigraphycally underlain by, from bottom to top, the Enugu/Nkporo, Mamu and Ajali Formation respectively, a complex geology that make citing of productive borehole in the area problematic leading to borehole failure and dry holes due to inadequate sampling. The study adopted a field and analytic sampling approach, integrating field geological, electrical resistivity and self-potential methods. The software, SedLog v3.1, InterpexIx1Dv.3, and Surfer v10 were employed for the data integration and interpretation. The result of the geological field and borehole data shows 11 sedimentary facies consisting of sandstone, shales and heterolith of sandstone/shale, with the aquifer zone mostly prevalent in the more porous sand-dominated horizons. Mostly the AK and HK were the dominant curve types. An average of 6 geo-electric layers were delineated across all transects with resistivity values ranging from 25.42 - 105.85 Ωm, 186.38 - 3383.3 Ωm, and 2992 - 6286.4 Ωm in the Enugu, Mamu and Ajali Formations respectively. The resistivity of the main aquifer layer ranges from 1 to 500 Ωm. The aquifer thickness within the study area varies between 95 and 140 m. The western and northwestern part of the study area which is underlain mainly by the Ajali Formation showed the highest groundwater potential in the area and suitable for citing productive boreholes.展开更多
Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the correspond...Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the corresponding software for effective image processing, and also equipped with a variety of sensor equipment to quickly obtain relevant measurement and mapping information, so as to provide the corresponding accurate measurement results. Short cycle, flexible, fast, reliable information, high efficiency, strong adaptability and reliable quality are the advantages of UAV.展开更多
研学旅行是中小学不可或缺的综合实践课程,是培养学生核心素养的重要途径。地理信息技术是中学地理教学的重要教学内容与手段。移动GIS集成GIS、GNSS、互联网技术等,在为研学旅行提供技术支撑的同时,有助于学生学习地理信息技术。文章...研学旅行是中小学不可或缺的综合实践课程,是培养学生核心素养的重要途径。地理信息技术是中学地理教学的重要教学内容与手段。移动GIS集成GIS、GNSS、互联网技术等,在为研学旅行提供技术支撑的同时,有助于学生学习地理信息技术。文章基于地理核心素养的培养要求,以“认识河南大学校园植被”为例,探究ArcGIS Field Maps在地理研学旅行中的应用。展开更多
This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarc...This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,etc.This improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas.展开更多
Willian Cavazza obtained a BSc in Geo-logical Sciences in 1983,summa cum lanude,from the AIma Mater Studiorum,Universityof Bologna.His thesis involved field mappingin a controversial late Palaeozoic portion ofthe Carn...Willian Cavazza obtained a BSc in Geo-logical Sciences in 1983,summa cum lanude,from the AIma Mater Studiorum,Universityof Bologna.His thesis involved field mappingin a controversial late Palaeozoic portion ofthe Carnic Alps,and resulted in the Bolognarecognition of the significant effects of the Hercynian orogeny in this area.Supported bygrants from the Italian Ministry of Education,Los Alamos National Laboratories,and theindustrial sector,William then moved to theUnited States where he obtained an MSc ingeology(1985)and a PhD in geology(1989)from the University of California,LosAngeles(UCLA).His MSc research focusedon sediment provenance and dispersal in theMiocene Española rift basin of New Mexico.His PhD dissertation dealt with the sedi-mentary basin analysis of the Ionian forearcbasin of southern Italy.Both projects weresupervised by Prof.Raymond V.Ingersoll.During his PhD years at UCLA he wasinvolved in other research projects,resultingin several papers on Laramide syntectonicsedimentation in Montana,supradetachmentsedimentation in the Mojave Desert,and thepalaeogeography of the Rio Grande rift.展开更多
Distribution of groundwater outflows(springs)is determined by a number of natural factors–the most important factor being geological structure.However,the relationship between spring location and environmental charac...Distribution of groundwater outflows(springs)is determined by a number of natural factors–the most important factor being geological structure.However,the relationship between spring location and environmental characteristics in flysch areas has not been studied extensively.The purpose of the paper is to analyze the determinants of springs location in a flysch massif based on a database of springs created in the course of detailed field mapping.展开更多
For an SOI-FPGA （silicon-on-insulator field programmable gate arrays） （VS1000） fabricated with 0.5 ttm SOI-CMOS （silicon-on-insulator complementary-metal-oxide-semiconductor） process, a complete integrated platf...For an SOI-FPGA （silicon-on-insulator field programmable gate arrays） （VS1000） fabricated with 0.5 ttm SOI-CMOS （silicon-on-insulator complementary-metal-oxide-semiconductor） process, a complete integrated platform of FPGA computer-aided design （CAD） toolset （VDK） is developed, which can convert the Verilog HDL （hardware description language） description into a bitstream and finally download it into an FPGA. Experiments and testing verify that this FPGA CAD works well and efficiently.展开更多
At present, the improvement of China's scientific and technological development level has a positive impact on the rich technical connotation of surveying and mapping field. In practice, in order to make scientifi...At present, the improvement of China's scientific and technological development level has a positive impact on the rich technical connotation of surveying and mapping field. In practice, in order to make scientific use of the multi-survey and one-in-one model that combines topographic mapping, real estate mapping and cadastral mapping, problems need to be analyzed, effective implementation suggestions should be found and solved to improve the implementation efficiency of the model. On this basis, this paper introduces the implementation problems and suggestions of multi-test integration.展开更多
Historic maps showing the temporal distribution of rice fields are important for precision agriculture,irrigation optimisation,forecasting crop yields,land use management and formulating policies.However,mapping rice ...Historic maps showing the temporal distribution of rice fields are important for precision agriculture,irrigation optimisation,forecasting crop yields,land use management and formulating policies.However,mapping rice felds using traditional ground surveys is impractical when high cost,time and labour requirements are considered,and the availability of such detailed records is limited.Although satellite remote sensing appears to be a viable solution,conventional segmentation and classification methods with spectral bands are often unable to contrast the distinct characteristics between rice fields and other vegetation classes.To this end,we explored a novel,Google Earth Engine(GEE)based multiindex random forest(RF)classification approach to map rice fields over two decades.Landsat images from 2000 to 2020 of two Sri Lankan rice cultivation districts were extracted from GEE and a multi-index RF classification algorithm was applied to distinguish the rice fields.The results showed above 80%accuracy for both training and validation,when compared against high spatial resolution Google Earth imagery.In essence,multi-index sampling and RF together synergised the compelling classifcation accuracy by effectively capturing vegetation,water(ponding)and soil characteristics unique to the rice felds using a single-click approach.The maps developed in this study were further compared against the MODIS land cover type product(MCD12Q1)and the corresponding superior statistics on rice fields demonstrated the robustness of the proposed approach.Future work seeking effective index combinations is recommended,and this approach can potentially be extended to other crop analyses elsewhere.展开更多
The InjectorⅡ, one of the two parallel injectors of the high-current superconducting proton driver linac for the China Accelerator-Driven System （C-ADS） project, is being designed and constructed by the Institute o...The InjectorⅡ, one of the two parallel injectors of the high-current superconducting proton driver linac for the China Accelerator-Driven System （C-ADS） project, is being designed and constructed by the Institute of Modern Physics. At present, the design work for the injector is almost finished. End-to-end simulation has been carried out using the TRACK multiparticle simulation code to check the match between each acceleration section and the performance of the injector as a whole. Moreover, multiparticle simulations with all kinds of errors and misalignments have been performed to define the requirements of each device. The simulation results indicate that the lattice design is robust. In this paper, the results of end-to-end simulation and error simulation with a 3-D field map are presented.展开更多
Background In-stent restenosis （ISR） has become one of the most challenging problems in patients with coronary heart disease. At present, using non-invasive methods to assess ISR is a hot topic. In this investigatio...Background In-stent restenosis （ISR） has become one of the most challenging problems in patients with coronary heart disease. At present, using non-invasive methods to assess ISR is a hot topic. In this investigation we attempted to explore the potential of magnetocardiography （MCG） in diagnosis of in-stent restenosis. Methods MCG was analyzed in 52 patients with coronary artery disease for three times： before stenting, one month and 7 months after successful intracoronary stenting. Results The average classification of total maps （ACTM） and the ratio of abnormal maps （RAM） were lower in 1 month after intracoronary stenting compared with that obtained before stent planting （2.91 vs 2.52, 65.74% vs 42.80%, P〈0.01）, while complex ventricular excitation index （CVEI） increased from -42.63 to -20.05 （P〈0.01）. In ISR subgroup （n=16）, RAM decreased in 1 month after intracoronary stenting compared to it before stenting （68.99% vs 45.26%, P〈0.05）. ACTM increased in 7 months compared to that obtained in 1 month after stenting （3.15 vs 2.51, P〈0.05）. According to the ROC curve, ACTM showed its unique diagnostic value in restenosis patients. The sensitivity and specificity of ACTM were 80.0%, 69.40%, respectively. Its positive predictive value and negative predictive value were 54.6% and 88.5%, respectively. Conclusions After successful intracoronary stenting, most parameters of MCG were improved. ACTM was of prognostic value in diagnosing ISR.展开更多
基金supported by the National Science Foundation of China(Grant No.52293423 and Grant No.52277031).
文摘After the fabrication of magnetic resonance superconducting magnets,the magnetic field inhomogeneity needs to be accurately measured for subsequent shimming.However,conventional measurement methods are susceptible to magnetic fields,have poor compatibility,and are difficult to adapt to various types of magnets.This paper proposes a new field measuring system based on a three-axis movable platform.The system utilizes non-magnetic materials and an innovative hand-wheel lifting design that can be adapted to various aperture magnets,thus obviating the necessity for electrically driven equipment and addressing safety concerns in strong magnetic fields.In addition,the measurement system offers high accuracy up to 1 mm and a wide measurable range.The fields of 3 T and 7 T magnets were mapped using the designed system with diameter of spherical volume(DSV)of 160 mm and 130 mm,respectively.Experimental results demonstrate that the magnetic field measurement system has strong compatibility and can accurately map the magnetic field at arbitrary positions,which is critical for shimming studies.
文摘The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambra Basin between latitudes 6˚43'N and 6˚47'N and longitudes 7˚28'E and 7˚32'E, it is stratigraphycally underlain by, from bottom to top, the Enugu/Nkporo, Mamu and Ajali Formation respectively, a complex geology that make citing of productive borehole in the area problematic leading to borehole failure and dry holes due to inadequate sampling. The study adopted a field and analytic sampling approach, integrating field geological, electrical resistivity and self-potential methods. The software, SedLog v3.1, InterpexIx1Dv.3, and Surfer v10 were employed for the data integration and interpretation. The result of the geological field and borehole data shows 11 sedimentary facies consisting of sandstone, shales and heterolith of sandstone/shale, with the aquifer zone mostly prevalent in the more porous sand-dominated horizons. Mostly the AK and HK were the dominant curve types. An average of 6 geo-electric layers were delineated across all transects with resistivity values ranging from 25.42 - 105.85 Ωm, 186.38 - 3383.3 Ωm, and 2992 - 6286.4 Ωm in the Enugu, Mamu and Ajali Formations respectively. The resistivity of the main aquifer layer ranges from 1 to 500 Ωm. The aquifer thickness within the study area varies between 95 and 140 m. The western and northwestern part of the study area which is underlain mainly by the Ajali Formation showed the highest groundwater potential in the area and suitable for citing productive boreholes.
文摘Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the corresponding software for effective image processing, and also equipped with a variety of sensor equipment to quickly obtain relevant measurement and mapping information, so as to provide the corresponding accurate measurement results. Short cycle, flexible, fast, reliable information, high efficiency, strong adaptability and reliable quality are the advantages of UAV.
文摘研学旅行是中小学不可或缺的综合实践课程,是培养学生核心素养的重要途径。地理信息技术是中学地理教学的重要教学内容与手段。移动GIS集成GIS、GNSS、互联网技术等,在为研学旅行提供技术支撑的同时,有助于学生学习地理信息技术。文章基于地理核心素养的培养要求,以“认识河南大学校园植被”为例,探究ArcGIS Field Maps在地理研学旅行中的应用。
基金partially supported by the National Key R&D Program of China(Nos.2019YFE03030002 and 2022YFE03030001)National Natural Science Foundation of China(Nos.12175186 and 12175055)the Natural Science Foundation of Sichuan Province(Nos.2022NSFSC1820 and 2023NSFSC1289)。
文摘This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,etc.This improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas.
文摘Willian Cavazza obtained a BSc in Geo-logical Sciences in 1983,summa cum lanude,from the AIma Mater Studiorum,Universityof Bologna.His thesis involved field mappingin a controversial late Palaeozoic portion ofthe Carnic Alps,and resulted in the Bolognarecognition of the significant effects of the Hercynian orogeny in this area.Supported bygrants from the Italian Ministry of Education,Los Alamos National Laboratories,and theindustrial sector,William then moved to theUnited States where he obtained an MSc ingeology(1985)and a PhD in geology(1989)from the University of California,LosAngeles(UCLA).His MSc research focusedon sediment provenance and dispersal in theMiocene Española rift basin of New Mexico.His PhD dissertation dealt with the sedi-mentary basin analysis of the Ionian forearcbasin of southern Italy.Both projects weresupervised by Prof.Raymond V.Ingersoll.During his PhD years at UCLA he wasinvolved in other research projects,resultingin several papers on Laramide syntectonicsedimentation in Montana,supradetachmentsedimentation in the Mojave Desert,and thepalaeogeography of the Rio Grande rift.
文摘Distribution of groundwater outflows(springs)is determined by a number of natural factors–the most important factor being geological structure.However,the relationship between spring location and environmental characteristics in flysch areas has not been studied extensively.The purpose of the paper is to analyze the determinants of springs location in a flysch massif based on a database of springs created in the course of detailed field mapping.
文摘For an SOI-FPGA （silicon-on-insulator field programmable gate arrays） （VS1000） fabricated with 0.5 ttm SOI-CMOS （silicon-on-insulator complementary-metal-oxide-semiconductor） process, a complete integrated platform of FPGA computer-aided design （CAD） toolset （VDK） is developed, which can convert the Verilog HDL （hardware description language） description into a bitstream and finally download it into an FPGA. Experiments and testing verify that this FPGA CAD works well and efficiently.
文摘At present, the improvement of China's scientific and technological development level has a positive impact on the rich technical connotation of surveying and mapping field. In practice, in order to make scientific use of the multi-survey and one-in-one model that combines topographic mapping, real estate mapping and cadastral mapping, problems need to be analyzed, effective implementation suggestions should be found and solved to improve the implementation efficiency of the model. On this basis, this paper introduces the implementation problems and suggestions of multi-test integration.
文摘Historic maps showing the temporal distribution of rice fields are important for precision agriculture,irrigation optimisation,forecasting crop yields,land use management and formulating policies.However,mapping rice felds using traditional ground surveys is impractical when high cost,time and labour requirements are considered,and the availability of such detailed records is limited.Although satellite remote sensing appears to be a viable solution,conventional segmentation and classification methods with spectral bands are often unable to contrast the distinct characteristics between rice fields and other vegetation classes.To this end,we explored a novel,Google Earth Engine(GEE)based multiindex random forest(RF)classification approach to map rice fields over two decades.Landsat images from 2000 to 2020 of two Sri Lankan rice cultivation districts were extracted from GEE and a multi-index RF classification algorithm was applied to distinguish the rice fields.The results showed above 80%accuracy for both training and validation,when compared against high spatial resolution Google Earth imagery.In essence,multi-index sampling and RF together synergised the compelling classifcation accuracy by effectively capturing vegetation,water(ponding)and soil characteristics unique to the rice felds using a single-click approach.The maps developed in this study were further compared against the MODIS land cover type product(MCD12Q1)and the corresponding superior statistics on rice fields demonstrated the robustness of the proposed approach.Future work seeking effective index combinations is recommended,and this approach can potentially be extended to other crop analyses elsewhere.
基金Supported by National Natural Science Foundation of China (91026001)
文摘The InjectorⅡ, one of the two parallel injectors of the high-current superconducting proton driver linac for the China Accelerator-Driven System （C-ADS） project, is being designed and constructed by the Institute of Modern Physics. At present, the design work for the injector is almost finished. End-to-end simulation has been carried out using the TRACK multiparticle simulation code to check the match between each acceleration section and the performance of the injector as a whole. Moreover, multiparticle simulations with all kinds of errors and misalignments have been performed to define the requirements of each device. The simulation results indicate that the lattice design is robust. In this paper, the results of end-to-end simulation and error simulation with a 3-D field map are presented.
文摘Background In-stent restenosis （ISR） has become one of the most challenging problems in patients with coronary heart disease. At present, using non-invasive methods to assess ISR is a hot topic. In this investigation we attempted to explore the potential of magnetocardiography （MCG） in diagnosis of in-stent restenosis. Methods MCG was analyzed in 52 patients with coronary artery disease for three times： before stenting, one month and 7 months after successful intracoronary stenting. Results The average classification of total maps （ACTM） and the ratio of abnormal maps （RAM） were lower in 1 month after intracoronary stenting compared with that obtained before stent planting （2.91 vs 2.52, 65.74% vs 42.80%, P〈0.01）, while complex ventricular excitation index （CVEI） increased from -42.63 to -20.05 （P〈0.01）. In ISR subgroup （n=16）, RAM decreased in 1 month after intracoronary stenting compared to it before stenting （68.99% vs 45.26%, P〈0.05）. ACTM increased in 7 months compared to that obtained in 1 month after stenting （3.15 vs 2.51, P〈0.05）. According to the ROC curve, ACTM showed its unique diagnostic value in restenosis patients. The sensitivity and specificity of ACTM were 80.0%, 69.40%, respectively. Its positive predictive value and negative predictive value were 54.6% and 88.5%, respectively. Conclusions After successful intracoronary stenting, most parameters of MCG were improved. ACTM was of prognostic value in diagnosing ISR.
