As a hybrid imaging modality that combines optical excitation with acoustic detection,photoacoustic tomography(PAT)has become one of the fastest growing biomedical imaging modalities.Among various types of transducer ...As a hybrid imaging modality that combines optical excitation with acoustic detection,photoacoustic tomography(PAT)has become one of the fastest growing biomedical imaging modalities.Among various types of transducer arrays used in a PAT system conguration,the linear array is the most commonly utilized due to its convenience and low-cost.Although linear array-based PAT has been quickly developed within the recent decade,there are still two major challenges that impair the overall performance of the PAT imaging system.Therst challenge is that the three-dimensional(3D)imaging capability of a linear array is limited due to its poor elevational resolution.The other challenge is that the geometrical shape of the linear array constrains light illumination.To date,substantial e®orts have been made to address the aforementioned challenges.This review will present current technologies for improving the elevation resolution and light delivery of linear array-based PAT systems.展开更多
There are rich oil and gas resources in Alberta oil sand mining area in Canada.Since the 1960s,the Canadian government decided to increase the mining intensity.However,the exploitation will bring many adverse effects....There are rich oil and gas resources in Alberta oil sand mining area in Canada.Since the 1960s,the Canadian government decided to increase the mining intensity.However,the exploitation will bring many adverse effects.In recent years,more people pay attention to the environmental protection and ecological restoration of mining area,such as issues related with changes of vegetated lands.Thus,the authors used the Landsat-5 TM and Landsat-8 OLI remote sensing images as the basic data sources,and obtained the land cover classification maps from 1995 to 2020 by ENVI.Based on the NDVI,NDMI and RVI,three images in each period are processed and output to explore the long-term impact of exploitation.The results show that from 1995 to 2020,the proportion of vegetation around mining areas decreased sharply,the scale of construction land in the mining area increased,and the vegetated land was changed to land types such as tailings pond,oil sand mine and other land types.In addition,three vegetation indexes decreased from 1995 to 2020.Although the exploitation of oil sand mining area brings great economic benefits,the environmental protection(especially vegetation)in oil sand mining areas should be paid more attention.展开更多
基金supported in part by the Career Catalyst Research Grant from the Susan G.Komen Foundation(No.CCR17481211).
文摘As a hybrid imaging modality that combines optical excitation with acoustic detection,photoacoustic tomography(PAT)has become one of the fastest growing biomedical imaging modalities.Among various types of transducer arrays used in a PAT system conguration,the linear array is the most commonly utilized due to its convenience and low-cost.Although linear array-based PAT has been quickly developed within the recent decade,there are still two major challenges that impair the overall performance of the PAT imaging system.Therst challenge is that the three-dimensional(3D)imaging capability of a linear array is limited due to its poor elevational resolution.The other challenge is that the geometrical shape of the linear array constrains light illumination.To date,substantial e®orts have been made to address the aforementioned challenges.This review will present current technologies for improving the elevation resolution and light delivery of linear array-based PAT systems.
基金supported by the National Key Research and Development Program of China(No.2020YFA0714103)China Scholarship Council(No.CSC201906175002)the Young Teachers and Students’Cutting-edge Funding of Jilin University,China(No.2020-JCXK-04).
文摘There are rich oil and gas resources in Alberta oil sand mining area in Canada.Since the 1960s,the Canadian government decided to increase the mining intensity.However,the exploitation will bring many adverse effects.In recent years,more people pay attention to the environmental protection and ecological restoration of mining area,such as issues related with changes of vegetated lands.Thus,the authors used the Landsat-5 TM and Landsat-8 OLI remote sensing images as the basic data sources,and obtained the land cover classification maps from 1995 to 2020 by ENVI.Based on the NDVI,NDMI and RVI,three images in each period are processed and output to explore the long-term impact of exploitation.The results show that from 1995 to 2020,the proportion of vegetation around mining areas decreased sharply,the scale of construction land in the mining area increased,and the vegetated land was changed to land types such as tailings pond,oil sand mine and other land types.In addition,three vegetation indexes decreased from 1995 to 2020.Although the exploitation of oil sand mining area brings great economic benefits,the environmental protection(especially vegetation)in oil sand mining areas should be paid more attention.
