Ancient outwash accumulations, deposited in Pleistocene with complicated sedimentary characteristics, are discovered in the midstream valley of Dadu River, Southwestern China. Their sedimentation characteristics are i...Ancient outwash accumulations, deposited in Pleistocene with complicated sedimentary characteristics, are discovered in the midstream valley of Dadu River, Southwestern China. Their sedimentation characteristics are investigated for gaining a deep insight into the dependency of Paleoclimate changes in this area. This is achieved by means of detailed site investigation, sampling and laboratory tests （grain size distribution and Electron Spin Resonance dating tests） for two representative outwash accumulations. Based on the present study, several main conclusions are drown out as follows： 1） The accumulations are composed mainly of coarse soils （coarse fraction is over 50%） and very coarse soils （coarse fraction is about 20%-35%, and very coarse fraction is over 55%）; 2） The coarse soils are sub-rounded well-sorted and sub-stratified to well-stratified, while the very coarse soils exhibit sub-rounded to sub-angular and poorly-sorted; 3） The accumulations are postulated to have been intermittently deposited in three time periods. This is evidenced by two layers of weathered/ residual clay, purple to brick red in color; and 4） It is inferred that the temperature in the study area increased over three time periods, i.e., 280 ka B.P. to 120 ka B.P., 110 ka B.P. to 80 ka B.P. and 70 ka B. P. to 25 ka B.P., and declined twice at 120 ka B.P. and 77 ka B.P. respectively.展开更多
Marine microalga Isochrysis galbana is an important feed species with a high nutritional value.Different from other uni-cellular algae,its cell contains two chloroplasts which are the major sites for lipid synthesis.H...Marine microalga Isochrysis galbana is an important feed species with a high nutritional value.Different from other uni-cellular algae,its cell contains two chloroplasts which are the major sites for lipid synthesis.Here,we optimized a chloroplast isola-tion approach suitable for the isolation of I.galbana chloroplasts and determined the purity and integrity of the isolated chloroplasts through microscopic observations and enzyme activity assay.The chloroplast lipids were analyzed with a ultrahigh-performance li-quid chromatography-Q Exactive Orbitrap-mass spectrometry.This newly developed isolation approach is simple and reliable to isolate chloroplasts with high integrity and purity.The average yield of intact chloroplasts was 15.3%±0.1%.Glycolipids and acyl-glycerols were the main chloroplast lipids.Glycolipids accounted for 56.6%of chloroplast lipid.Digalactosyldiacylglycerol(DGDG),monogalactosyldiacylglycerol(MGDG)and sulfoquinovosyldiacylglycerol(SQDG)were the main glyceroglycolipids.The fatty acyl R1/R2 were mostly 18:4/16:1,18:3/16:1 and 18:4/18:5 in DGDGs,14:0/18:4,18:4/18:5,18:4/18:4 and 18:3/18:4 in MGDGs and 16:0/14:0,16:0/18:3,and 18:4/18:3 in SQDGs.In addition,diacylglycerol(DAG)was the most abundant acylglycerols;the content of 22:6/18:4-DAG was the highest.There was a little amount of glycosphingolipid(GSL)in chloroplast.Digalactosylmonoglyceride(DGMG),monogalactosylmonoglyceride(MGMG),sulfoquinovosylmonoacylglycerol(SQMG),monoglyceride(MAG),phospholi-pids(PLs),ceramide(Cer)and betaine lipids were nearly undetectable in chloroplast.The fatty acid proportions of DGDGs,MGDGs,SQDGs,DAGs,triglycerides(TAGs)and GSLs were either higher or lower than or similar to those of whole-cell.Collectively,our isolation approach is applicable to many aspects of chloroplast biology,and may offer a reference for the isolation of chloroplasts from other marine microalgae.展开更多
Landslide susceptibility evaluation at regional scale is commonly performed based dominantly on the analysis of geological and geomorphological conditions of historical landslide cases. The main content of this type o...Landslide susceptibility evaluation at regional scale is commonly performed based dominantly on the analysis of geological and geomorphological conditions of historical landslide cases. The main content of this type of evaluation covers identifying key casual factors, their critical groupings and relative importance. The present study demonstrates an application of the above concept to a 90 km long segment of Jinsbajiang River valley in China. Correlations of landslide occurrence with potential causative factors are derived according to interpretation of field investigation. Lithology, orientation of bedding planes, slope angle, stream action, rainfall and earthquake intensity are selectively recognized as identifiable/measurable causative factors to establish a factor domain. The membership grades, for field values of quantitative factors, to the susceptibility classes are determined based on the construction of fuzzy sets, while those for descriptive factors are assigned from a fuzzy score table. The analytic hierarchy process （AHP） is adopted for assigning weights to each individual factor. Subsequently, the evaluation is implemented in a GIS program IDRISI, where four classes of landslide susceptibility are identified and delineated in the subject area. The approach described in the present paper showed consistence with the nature and availability of data for evaluating landslide susceptibility at regional scale. The methodology presented can be effectively employed by relevant authorities to identify risky areas for dislocating major infrastructural project, and develop management strategies for land use.展开更多
基金financially supported by the Young People's Foundation of State Key Laboratory of Geo-hazard Prevention and Geo-environment Protection (SKLGP2010Z007)
文摘Ancient outwash accumulations, deposited in Pleistocene with complicated sedimentary characteristics, are discovered in the midstream valley of Dadu River, Southwestern China. Their sedimentation characteristics are investigated for gaining a deep insight into the dependency of Paleoclimate changes in this area. This is achieved by means of detailed site investigation, sampling and laboratory tests （grain size distribution and Electron Spin Resonance dating tests） for two representative outwash accumulations. Based on the present study, several main conclusions are drown out as follows： 1） The accumulations are composed mainly of coarse soils （coarse fraction is over 50%） and very coarse soils （coarse fraction is about 20%-35%, and very coarse fraction is over 55%）; 2） The coarse soils are sub-rounded well-sorted and sub-stratified to well-stratified, while the very coarse soils exhibit sub-rounded to sub-angular and poorly-sorted; 3） The accumulations are postulated to have been intermittently deposited in three time periods. This is evidenced by two layers of weathered/ residual clay, purple to brick red in color; and 4） It is inferred that the temperature in the study area increased over three time periods, i.e., 280 ka B.P. to 120 ka B.P., 110 ka B.P. to 80 ka B.P. and 70 ka B. P. to 25 ka B.P., and declined twice at 120 ka B.P. and 77 ka B.P. respectively.
基金supported by the Ningbo Science and Technology Research Projects(No.2019B10006)the Na-tional Key Research and Development Program of China(No.2019YFD0900400)+3 种基金the Zhejiang Major Science Pro-ject(No.2019C02057)the China Agriculture Research System of MOF and MARA,the Natural Science Founda-tion of Ningbo(No.2019A610416)the Ningbo Science and Technology Research Projects(No.2019C10023)the National Natural Science Foundation of China(No.31801724).
文摘Marine microalga Isochrysis galbana is an important feed species with a high nutritional value.Different from other uni-cellular algae,its cell contains two chloroplasts which are the major sites for lipid synthesis.Here,we optimized a chloroplast isola-tion approach suitable for the isolation of I.galbana chloroplasts and determined the purity and integrity of the isolated chloroplasts through microscopic observations and enzyme activity assay.The chloroplast lipids were analyzed with a ultrahigh-performance li-quid chromatography-Q Exactive Orbitrap-mass spectrometry.This newly developed isolation approach is simple and reliable to isolate chloroplasts with high integrity and purity.The average yield of intact chloroplasts was 15.3%±0.1%.Glycolipids and acyl-glycerols were the main chloroplast lipids.Glycolipids accounted for 56.6%of chloroplast lipid.Digalactosyldiacylglycerol(DGDG),monogalactosyldiacylglycerol(MGDG)and sulfoquinovosyldiacylglycerol(SQDG)were the main glyceroglycolipids.The fatty acyl R1/R2 were mostly 18:4/16:1,18:3/16:1 and 18:4/18:5 in DGDGs,14:0/18:4,18:4/18:5,18:4/18:4 and 18:3/18:4 in MGDGs and 16:0/14:0,16:0/18:3,and 18:4/18:3 in SQDGs.In addition,diacylglycerol(DAG)was the most abundant acylglycerols;the content of 22:6/18:4-DAG was the highest.There was a little amount of glycosphingolipid(GSL)in chloroplast.Digalactosylmonoglyceride(DGMG),monogalactosylmonoglyceride(MGMG),sulfoquinovosylmonoacylglycerol(SQMG),monoglyceride(MAG),phospholi-pids(PLs),ceramide(Cer)and betaine lipids were nearly undetectable in chloroplast.The fatty acid proportions of DGDGs,MGDGs,SQDGs,DAGs,triglycerides(TAGs)and GSLs were either higher or lower than or similar to those of whole-cell.Collectively,our isolation approach is applicable to many aspects of chloroplast biology,and may offer a reference for the isolation of chloroplasts from other marine microalgae.
基金partially supported by Major State Basic Research Development Program(Grant No. 2011BAK12B03)Key Project of Chinese Ministry of Education(Project No.211156)+1 种基金Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology)(Grant No.SKLGP2012K034)Opening Fund of Key Laboratory of Karst Environment and Geohazard Prevention,Ministry of Education(Guizhou University)(Grant No.2011-K01)
文摘Landslide susceptibility evaluation at regional scale is commonly performed based dominantly on the analysis of geological and geomorphological conditions of historical landslide cases. The main content of this type of evaluation covers identifying key casual factors, their critical groupings and relative importance. The present study demonstrates an application of the above concept to a 90 km long segment of Jinsbajiang River valley in China. Correlations of landslide occurrence with potential causative factors are derived according to interpretation of field investigation. Lithology, orientation of bedding planes, slope angle, stream action, rainfall and earthquake intensity are selectively recognized as identifiable/measurable causative factors to establish a factor domain. The membership grades, for field values of quantitative factors, to the susceptibility classes are determined based on the construction of fuzzy sets, while those for descriptive factors are assigned from a fuzzy score table. The analytic hierarchy process （AHP） is adopted for assigning weights to each individual factor. Subsequently, the evaluation is implemented in a GIS program IDRISI, where four classes of landslide susceptibility are identified and delineated in the subject area. The approach described in the present paper showed consistence with the nature and availability of data for evaluating landslide susceptibility at regional scale. The methodology presented can be effectively employed by relevant authorities to identify risky areas for dislocating major infrastructural project, and develop management strategies for land use.
