Paleosalinity records of the Tianluoshan site are derived from measurations data of clay mineral, boron, strontium, barium, after field sampling in three profiles of the Tianluoshan site. The relative sea level change...Paleosalinity records of the Tianluoshan site are derived from measurations data of clay mineral, boron, strontium, barium, after field sampling in three profiles of the Tianluoshan site. The relative sea level changes are discussed according to the lab results. The record indicates that the region where the Tianluoshan site located has witnessed at least three times of relative sea level high-stand before, during and after the Hemudu period. Based on previous researches, this paper also focuses on discussing several environmental elements, the inter-relationships between environmental condition, human activities and development of the Hemudu culture comprehensively.展开更多
With the development of economy,the impact of human activities on ecological environment is increasing,and environmental protection work is important.Trace elements(Co,Ni,Cu,Pb,Zn,Cd,Cr,and Sc)in surface fi ne-grained...With the development of economy,the impact of human activities on ecological environment is increasing,and environmental protection work is important.Trace elements(Co,Ni,Cu,Pb,Zn,Cd,Cr,and Sc)in surface fi ne-grained sediment samples from the Jiaozhou Bay catchment were selected to evaluate their 2015 environmental background values and the environmental quality.Using statistical analysis,the environmental background values(ranges)of Sc,Co,Ni,Cu,Pb,Zn,Cd,and Cr were calculated,being 13.1(10.8-15.4),12.4(8.6-16.2),32.0(22.9-41.2),29.6(13.5-64.9),24.1(13.0-44.6),77.6(38.5-156.5),0.07(0.02-0.20),and 82.5(66.5-104.0)mg/kg,respectively.The enrichment factor,contamination factor,and pollution load index were used to evaluate the pollution status of the Jiaozhou Bay catchment.The environmental background values of most elements are higher than those of the upper continental crust and lower than those of global shale.At present,the pollution in the eastern Jiaozhou Bay is much higher than that in the western part.The results shall be helpful for future management for trace element pollution monitoring in the Jiaozhou Bay catchment.展开更多
High spatial and spectral resolution sensors such as Landsat Thematic mapper wereusually used to estimate the suspended sediment concentrstions in the coastal zones. But few peoplehave used SPOT image in estimating s...High spatial and spectral resolution sensors such as Landsat Thematic mapper wereusually used to estimate the suspended sediment concentrstions in the coastal zones. But few peoplehave used SPOT image in estimating suspended sedanment concentlations. When studying thesuspended sediment concentlation in Danshui hiver in Taiwan. SPOT adage was used because of itshigher spatial resolution and Danshui hiver being not as wide enough as the coastal area. The riversuspended sediment concentlation was divided into four levels by MLC classifer. Composite ofband1 and band2 was found the best combination to express the suspended sediment. And therelationship of river suspended sediment and its environmental background was analyzed byoverlaying the map of suspended sediment, vegetation type and pollution resouxces.展开更多
Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectr...Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.展开更多
The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the...The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.展开更多
[Objective]The research aimed to study HCH persistence in Jiaozhou Bay.[Method]Based on the investigation data in Jiaozhou Bay in April,August,September and October of 1989,we analyzed the source,distribution and migr...[Objective]The research aimed to study HCH persistence in Jiaozhou Bay.[Method]Based on the investigation data in Jiaozhou Bay in April,August,September and October of 1989,we analyzed the source,distribution and migration status of HCH in sea area of Jiaozhou Bay.By using structural model of HCH environmental background value in Jiaozhou Bay,basic background value,input amount of terrestrial runoff and environmental background value of HCH in Jiaozhou Bay were calculated.[Result]Basic background value of HCH in water area of Jiaozhou Bay was 0.012 7μg/L,HCH input amount of terrestrial runoff was during 0-0.057 1μg/L,HCH content input by ocean current was 0μg/L.Then,environmental background value of HCH in water area of Jiaozhou Bay was during 0.012 7-0.069 8μg/L.[Conclusion]HCH needed long time migrating from land to sea bottom,and experienced terrestrial migration process,water migration process,settlement process and biological migration cycle process.In these migration processes,HCH was persistent,and always caused threats and harms on organism.展开更多
During CHINARE-22 in austral summer of 2005-2006, a lake sediment core named DG4, which is impacted by penguin droppings, was retrieved from a lake catchment in Gardner Island of Vestfold Hills, East Antarctica. In th...During CHINARE-22 in austral summer of 2005-2006, a lake sediment core named DG4, which is impacted by penguin droppings, was retrieved from a lake catchment in Gardner Island of Vestfold Hills, East Antarctica. In this study, the concentrations of characteristic elements in the core, local bedrocks and fresh penguin guanos were determined. P, Se, F, S, As, Sr and Cu in DG4 were identified as the bio-element assemblage by R-clustering analysis and compared with those in the local bedrocks and fresh guanos, the results are similar to Y2 in Ardley Island, Antarctic Peninsula. On this basis, P and Se were identified as the optimum bio-elements in DG4 and F, P and S were identified in Y2, respectively. This work will provides the foundation for reconstructing the past penguin populations in Gardner Island of Vest- fold Hills, East Antarctica and comparing the penguin population dynamics between East Antarctica and Antarctic Peninsula.展开更多
This study analyzes landfall locations of tropical cyclones(TCs)over the western North Pacific during 1979–2018.Results demonstrate that the landfall locations of TCs over this region have shifted northward during th...This study analyzes landfall locations of tropical cyclones(TCs)over the western North Pacific during 1979–2018.Results demonstrate that the landfall locations of TCs over this region have shifted northward during the last four decades,primarily due to the shift of landfalling TC tracks,with the decreasing/increasing proportion of westward/northward TC tracks.In particular,the northward shift of the landfalling TCs was not related to their formation locations,which have not markedly changed,whereas"no-landed"TCs have significantly shifted northward.TC movement was significantly and positively correlated to the zonal component of the steering flow,while the correlation between TC movement and the meridional component of the steering flow was relatively unobvious.The westward steering flow in the tropical central Pacific that occurred around the formation and early development of the westward TCs was significantly weakened,which was unfavorable for their westward movement,thereby,causing the higher proportions of northward moving tracks.This weakened westward flow was related to the northward shift of the subtropical high ridge,which was caused by significant weakening of the southern part of the subtropical high.The vertical wind shear,sea surface temperature,and convective available potential energy also showed that the northern region of the western North Pacific became more favorable for TC development,whereas the upper divergence,low-layer relative vorticity,and accumulated water vapor content were not obviously related to the northward shift of TCs.展开更多
The effect of background light on the imaging quality of three typical ghost imaging(GI) lidar systems(namely narrow pulsed GI lidar, heterodyne GI lidar, and pulse-compression GI lidar via coherent detection) is inve...The effect of background light on the imaging quality of three typical ghost imaging(GI) lidar systems(namely narrow pulsed GI lidar, heterodyne GI lidar, and pulse-compression GI lidar via coherent detection) is investigated. By computing the signal-to-noise ratio(SNR) of fluctuation-correlation GI, our analytical results, which are backed up by numerical simulations, demonstrate that pulse-compression GI lidar via coherent detection has the strongest capacity against background light, whereas the reconstruction quality of narrow pulsed GI lidar is the most vulnerable to background light. The relationship between the peak SNR of the reconstruction image andσ(namely, the signal power to background power ratio) for the three GI lidar systems is also presented, and theresults accord with the curve of SNR-σ.展开更多
The variation in environmental scattering background is a major source of systematic errors in X- ray inspection and measurement systems. As the energy of these photons consisting of environmental scattering backgroun...The variation in environmental scattering background is a major source of systematic errors in X- ray inspection and measurement systems. As the energy of these photons consisting of environmental scattering background is much lower generally, the Cerenkov detectors having the detection threshold are likely insensitive to them and able to exclude their influence. A thickness measurement experiment is designed to verify the idea by employing a Cerenkov detector and an ionizing chamber for comparison. Furthermore, it is also found that the application of the Cerenkov detectors is helpful to exclude another systematic error from the variation of low energy components in the spectrum incident on the detector volume.展开更多
Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms res...Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin （Diptera： Drosophilidae） pop- ulations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead （Pb）. To determine whether flies from different natural populations exposed to the Pb-contaminated media in the laboratory show population spe- cific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations （F2, Fs, and Fs） for fecundity, de- velopmental time, and egg-to-adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution,展开更多
基金National Science and Technology Supporting Project, No.2006BAK21B02 National Natural Science Foundation of China, No.40671016+4 种基金 National Key and Basic Development Research Project of China, No.2003CB415201 Program of Archeological Research Center of Peking University Youth Science Foundation of NSFC, No： 40901012 ^14C ages were tested by Scientific and Technological Archaeology and Heritage Conservation Laboratory in School of Archeology and Museology, Peking University the percentage content of clay minerals was determined by Dr. Wang Hejin in School of Earth and Space Sciences, Peking University, who was helpful in extracting the clay minerals trace elements were determined by the Hebei Provincial Institute of Geological Survey.
文摘Paleosalinity records of the Tianluoshan site are derived from measurations data of clay mineral, boron, strontium, barium, after field sampling in three profiles of the Tianluoshan site. The relative sea level changes are discussed according to the lab results. The record indicates that the region where the Tianluoshan site located has witnessed at least three times of relative sea level high-stand before, during and after the Hemudu period. Based on previous researches, this paper also focuses on discussing several environmental elements, the inter-relationships between environmental condition, human activities and development of the Hemudu culture comprehensively.
基金Supported by the Shandong Provincial Natural Science Foundation of China(No.ZR2020MD061)the Construction of Public Scientifi c Research Platform for Hydrobiology and Biotechnology,a Central-Government-Led Local Science and Technology Development Foundation(No.ZY2021HN04)the Independent Project of Hainan Provincial Key Laboratory of Marine Geological Resources and Environment(Nos.ZZ[2020]2019256-01,2019256[2020]HNHSKC-01)。
文摘With the development of economy,the impact of human activities on ecological environment is increasing,and environmental protection work is important.Trace elements(Co,Ni,Cu,Pb,Zn,Cd,Cr,and Sc)in surface fi ne-grained sediment samples from the Jiaozhou Bay catchment were selected to evaluate their 2015 environmental background values and the environmental quality.Using statistical analysis,the environmental background values(ranges)of Sc,Co,Ni,Cu,Pb,Zn,Cd,and Cr were calculated,being 13.1(10.8-15.4),12.4(8.6-16.2),32.0(22.9-41.2),29.6(13.5-64.9),24.1(13.0-44.6),77.6(38.5-156.5),0.07(0.02-0.20),and 82.5(66.5-104.0)mg/kg,respectively.The enrichment factor,contamination factor,and pollution load index were used to evaluate the pollution status of the Jiaozhou Bay catchment.The environmental background values of most elements are higher than those of the upper continental crust and lower than those of global shale.At present,the pollution in the eastern Jiaozhou Bay is much higher than that in the western part.The results shall be helpful for future management for trace element pollution monitoring in the Jiaozhou Bay catchment.
文摘High spatial and spectral resolution sensors such as Landsat Thematic mapper wereusually used to estimate the suspended sediment concentrstions in the coastal zones. But few peoplehave used SPOT image in estimating suspended sedanment concentlations. When studying thesuspended sediment concentlation in Danshui hiver in Taiwan. SPOT adage was used because of itshigher spatial resolution and Danshui hiver being not as wide enough as the coastal area. The riversuspended sediment concentlation was divided into four levels by MLC classifer. Composite ofband1 and band2 was found the best combination to express the suspended sediment. And therelationship of river suspended sediment and its environmental background was analyzed byoverlaying the map of suspended sediment, vegetation type and pollution resouxces.
基金supported by key task project in Sicence for earthquake resilience No.XH17053the National Key Scientific Instrument and Equipment Development Projects of China(Grant No.2012YQ10022506)
文摘Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.
文摘The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.
基金Supported by Key Laboratory Item of Colleges and Universities,Guizhou Department of Education,China([2012]003)Research Conditions Help Project of Guizhou High-level Talent,China(TZJF-2011-44)+3 种基金Support Plan Program for Excellent Talents in New Century,Ministry of Education,China(NCET-12-0659)Governor Capital Fund for Excellent Education Talent in Guizhou,China([2012]71)Guiyang Low-carbon Science and Technology Plan Project,China(2012205)Research Fund of Director in North China Sea Environmental Monitoring Center of State Oceanic Administration,China(05EMC16)
文摘[Objective]The research aimed to study HCH persistence in Jiaozhou Bay.[Method]Based on the investigation data in Jiaozhou Bay in April,August,September and October of 1989,we analyzed the source,distribution and migration status of HCH in sea area of Jiaozhou Bay.By using structural model of HCH environmental background value in Jiaozhou Bay,basic background value,input amount of terrestrial runoff and environmental background value of HCH in Jiaozhou Bay were calculated.[Result]Basic background value of HCH in water area of Jiaozhou Bay was 0.012 7μg/L,HCH input amount of terrestrial runoff was during 0-0.057 1μg/L,HCH content input by ocean current was 0μg/L.Then,environmental background value of HCH in water area of Jiaozhou Bay was during 0.012 7-0.069 8μg/L.[Conclusion]HCH needed long time migrating from land to sea bottom,and experienced terrestrial migration process,water migration process,settlement process and biological migration cycle process.In these migration processes,HCH was persistent,and always caused threats and harms on organism.
基金supported by the National Natural Science Foundation (No.40730107 and No.40676004)Australia Antarctic Division Science Project (AAD2873)the opening foundation of CAS key laboratory of Isotope Geochronology and Geochemistry.
文摘During CHINARE-22 in austral summer of 2005-2006, a lake sediment core named DG4, which is impacted by penguin droppings, was retrieved from a lake catchment in Gardner Island of Vestfold Hills, East Antarctica. In this study, the concentrations of characteristic elements in the core, local bedrocks and fresh penguin guanos were determined. P, Se, F, S, As, Sr and Cu in DG4 were identified as the bio-element assemblage by R-clustering analysis and compared with those in the local bedrocks and fresh guanos, the results are similar to Y2 in Ardley Island, Antarctic Peninsula. On this basis, P and Se were identified as the optimum bio-elements in DG4 and F, P and S were identified in Y2, respectively. This work will provides the foundation for reconstructing the past penguin populations in Gardner Island of Vest- fold Hills, East Antarctica and comparing the penguin population dynamics between East Antarctica and Antarctic Peninsula.
基金supported by the Fundamental Research Funds of the Special Program for Key Research and Development of Guangdong Province(Grant No.2019B111101002)Guangzhou Science and Technology Planning Project(Grant No.201903010036)+2 种基金China Postdoctoral Science Foundation(Grant No.2020M683021)National Natural Science Foundation of China(Grant Nos.42075004,41875021,and 41830533)Key Laboratory of Tropical Atmosphere-Ocean System(Sun Yat-sen University),Ministry of Education。
文摘This study analyzes landfall locations of tropical cyclones(TCs)over the western North Pacific during 1979–2018.Results demonstrate that the landfall locations of TCs over this region have shifted northward during the last four decades,primarily due to the shift of landfalling TC tracks,with the decreasing/increasing proportion of westward/northward TC tracks.In particular,the northward shift of the landfalling TCs was not related to their formation locations,which have not markedly changed,whereas"no-landed"TCs have significantly shifted northward.TC movement was significantly and positively correlated to the zonal component of the steering flow,while the correlation between TC movement and the meridional component of the steering flow was relatively unobvious.The westward steering flow in the tropical central Pacific that occurred around the formation and early development of the westward TCs was significantly weakened,which was unfavorable for their westward movement,thereby,causing the higher proportions of northward moving tracks.This weakened westward flow was related to the northward shift of the subtropical high ridge,which was caused by significant weakening of the southern part of the subtropical high.The vertical wind shear,sea surface temperature,and convective available potential energy also showed that the northern region of the western North Pacific became more favorable for TC development,whereas the upper divergence,low-layer relative vorticity,and accumulated water vapor content were not obviously related to the northward shift of TCs.
基金National Natural Science Foundation of China(NSFC)(61571427)Ministry of Science and Technology of the People’s Republic of China(MOST)(2013AA122901)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2013162)
文摘The effect of background light on the imaging quality of three typical ghost imaging(GI) lidar systems(namely narrow pulsed GI lidar, heterodyne GI lidar, and pulse-compression GI lidar via coherent detection) is investigated. By computing the signal-to-noise ratio(SNR) of fluctuation-correlation GI, our analytical results, which are backed up by numerical simulations, demonstrate that pulse-compression GI lidar via coherent detection has the strongest capacity against background light, whereas the reconstruction quality of narrow pulsed GI lidar is the most vulnerable to background light. The relationship between the peak SNR of the reconstruction image andσ(namely, the signal power to background power ratio) for the three GI lidar systems is also presented, and theresults accord with the curve of SNR-σ.
基金Supported by National Natural Science Foundation of China (10775082)
文摘The variation in environmental scattering background is a major source of systematic errors in X- ray inspection and measurement systems. As the energy of these photons consisting of environmental scattering background is much lower generally, the Cerenkov detectors having the detection threshold are likely insensitive to them and able to exclude their influence. A thickness measurement experiment is designed to verify the idea by employing a Cerenkov detector and an ionizing chamber for comparison. Furthermore, it is also found that the application of the Cerenkov detectors is helpful to exclude another systematic error from the variation of low energy components in the spectrum incident on the detector volume.
文摘Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin （Diptera： Drosophilidae） pop- ulations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead （Pb）. To determine whether flies from different natural populations exposed to the Pb-contaminated media in the laboratory show population spe- cific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations （F2, Fs, and Fs） for fecundity, de- velopmental time, and egg-to-adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution,
