To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second ...To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.展开更多
Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Theref...Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Therefore, they can be effectively used to identify these grotmd objects which are difficult to discriminate by using wide-band data, and show much promise in geological survey. At the height of 1500 m, have 36 bands in visible to the CASI hyperspectral data near-infrared spectral range, with a spectral resolution of 19 nm and a space resolution of 0.9 m. The SASI data have 101 bands in the shortwave infrared spectral range, with a spectral resolution of 15 nm and a space resolution of 2.25 m. In 2010, China Geological Survey deployed an airborne CASI/SASI hyperspectral measurement project, and selected the Liuyuan and Fangshankou areas in the Beishan metallogenic belt of Gansu Province, and the Nachitai area of East Kunlun metallogenic belt in Qinghai Province to conduct geological survey. The work period of this project was three years.展开更多
Due to the extremely complex geological conditions in the Bohai Strait, active faults is very developed and earthquake activity occurs frequently. It is of great importance to evaluate the regional crustal stability f...Due to the extremely complex geological conditions in the Bohai Strait, active faults is very developed and earthquake activity occurs frequently. It is of great importance to evaluate the regional crustal stability for the planning and construction of the Trans-straits Passage. In this study, the authors carry out the evaluation by means of buffer analysis, topology analysis and overlay analysis based on ArcGIS software. The evaluation mainly analyzed six assessment factors of Bohai Strait including neotectonic activity, active faults distribution, seismicity, tectonic stress fields, Bouguer gravity anomaly and geological disasters. In brief, the crustal stability of the eastern North Yellow Sea Basin is best, while that of the Bohai Basin and southwest Bohai Strait is poor. Meanwhile, small and frequent earthquakes in the southern Strait and geological disasters developed in the northern and central Strait such as tidal ridge and shallow gas which may adversely impact on the Trans-straits Passage construction.展开更多
AIM To unravel relationships between gastrointestinal(GI)symptoms impairing quality of life(QOL)and clinical profiles of diabetes mellitus(DM)patients. METHODS We enrolled 134 outpatients with type 2 DM.Mean age was 6...AIM To unravel relationships between gastrointestinal(GI)symptoms impairing quality of life(QOL)and clinical profiles of diabetes mellitus(DM)patients. METHODS We enrolled 134 outpatients with type 2 DM.Mean age was 64.7 years,mean body mass index was 24.7 RESULTS Lower abdominal symptoms were found to be more frequent than those affecting the upper abdomen.Diabetic duration and medications showed associations with GI symptoms.We identified differences in peak prevalences of the five symptoms.Gastralgia(P=0.02vs 10-14 years)and total GI symptoms(P=0.01 and P=0.02 vs 5-9 years and 10-14 years,respectively)peaked at a diabetes duration of 15-19 years.Heartburn(P=0.004)and postprandial fullness(P=0.03)tended to increase with disease duration.Constipation and diarrhea showed bimodal peaks,with the first early and the second late(e.g.,P=0.03 at 15-19 years vs 10-14years for diarrhea)in the disease course.Finally,GI symptoms showed clustering that reflected the region of the GI tract affected,i.e.,constipation and diarrhea had similar frequencies(P<0.0001). CONCLUSION Our study highlights the importance of questioning patients about QOL impairment due to abdominal symptoms,especially in the early and the late periods of diabetes.展开更多
基金supported by China Geological Survey(DD20230554,DD20230089)the Strategic Priority Research Program of the Chinese Academy of Science(XDA28020302)the funding project of Northeast Geological S&T Innovation Center of China Geological Survey(QCJJ2022-40).
文摘To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.
基金funded by China Geological Survey (grant no.1212011120899)the Department of Geology & Mining, China National Nuclear Corporation (grant no.201498)
文摘Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Therefore, they can be effectively used to identify these grotmd objects which are difficult to discriminate by using wide-band data, and show much promise in geological survey. At the height of 1500 m, have 36 bands in visible to the CASI hyperspectral data near-infrared spectral range, with a spectral resolution of 19 nm and a space resolution of 0.9 m. The SASI data have 101 bands in the shortwave infrared spectral range, with a spectral resolution of 15 nm and a space resolution of 2.25 m. In 2010, China Geological Survey deployed an airborne CASI/SASI hyperspectral measurement project, and selected the Liuyuan and Fangshankou areas in the Beishan metallogenic belt of Gansu Province, and the Nachitai area of East Kunlun metallogenic belt in Qinghai Province to conduct geological survey. The work period of this project was three years.
基金This work was supported by the National Natural Science Foundation of China (41506119,41276060)the Geological Investigation Project of China Geological Survey (201200504,DD20191003). Thanks Prof. Xu Jie,Zhang Lifang and other anonymous reviewers for their comments and suggestions,which significantly improved the quality of the manuscript.
文摘Due to the extremely complex geological conditions in the Bohai Strait, active faults is very developed and earthquake activity occurs frequently. It is of great importance to evaluate the regional crustal stability for the planning and construction of the Trans-straits Passage. In this study, the authors carry out the evaluation by means of buffer analysis, topology analysis and overlay analysis based on ArcGIS software. The evaluation mainly analyzed six assessment factors of Bohai Strait including neotectonic activity, active faults distribution, seismicity, tectonic stress fields, Bouguer gravity anomaly and geological disasters. In brief, the crustal stability of the eastern North Yellow Sea Basin is best, while that of the Bohai Basin and southwest Bohai Strait is poor. Meanwhile, small and frequent earthquakes in the southern Strait and geological disasters developed in the northern and central Strait such as tidal ridge and shallow gas which may adversely impact on the Trans-straits Passage construction.
文摘AIM To unravel relationships between gastrointestinal(GI)symptoms impairing quality of life(QOL)and clinical profiles of diabetes mellitus(DM)patients. METHODS We enrolled 134 outpatients with type 2 DM.Mean age was 64.7 years,mean body mass index was 24.7 RESULTS Lower abdominal symptoms were found to be more frequent than those affecting the upper abdomen.Diabetic duration and medications showed associations with GI symptoms.We identified differences in peak prevalences of the five symptoms.Gastralgia(P=0.02vs 10-14 years)and total GI symptoms(P=0.01 and P=0.02 vs 5-9 years and 10-14 years,respectively)peaked at a diabetes duration of 15-19 years.Heartburn(P=0.004)and postprandial fullness(P=0.03)tended to increase with disease duration.Constipation and diarrhea showed bimodal peaks,with the first early and the second late(e.g.,P=0.03 at 15-19 years vs 10-14years for diarrhea)in the disease course.Finally,GI symptoms showed clustering that reflected the region of the GI tract affected,i.e.,constipation and diarrhea had similar frequencies(P<0.0001). CONCLUSION Our study highlights the importance of questioning patients about QOL impairment due to abdominal symptoms,especially in the early and the late periods of diabetes.
