Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and th...Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous paleo-uplifts around Central Sichuan, paleo erosion surfaces of the top boundary of Maokou Formation in eastern and southern Sichuan Basin, paleo erosion surfaces of the top boundary of the Leikoupo Formation in central and western Sichuan Basin.展开更多
Medium-and long-chain triacylglycerols(MLCT)rich in arachidonic acid(ARA)at sn-2 position were synthesized by a two-step enzymatic method.Firstly,sn-2 monoacylglycerols(MAG)were synthesized at a temperature of 25℃ by...Medium-and long-chain triacylglycerols(MLCT)rich in arachidonic acid(ARA)at sn-2 position were synthesized by a two-step enzymatic method.Firstly,sn-2 monoacylglycerols(MAG)were synthesized at a temperature of 25℃ by enzymatic alcoholysis.The MAG with 69.42%ARA at sn-2 position were obtained by solvent extraction and low temperature solvent crystallization.Secondly,the MLCT rich in ARA at sn-2 position and capric acid(CA)at sn-1,3 positions were produced by enzymatic esterification.Under the optimal conditions(MAG:CA=1:3(mol/mol),0.05 MPa vacuum,8% Lipozyme RM IM,5 h,25℃),the content of triacylglycerol was up to 93.60%.The triacylglycerol in the form of C10:0-C20:4-C10:0(including isomers)was about 40.43%.The ARA contents in the total and sn-2 fatty acid composition of the final product were 32.35%and 51.12%,respectively.MLCT rich in ARA at sn-2 position were successfully produced and the product has the potential application for functional food and infant formula.展开更多
More than a half of strong earthquakes in the world are located in shallow depth at the subducting plate boundary in squeezed zones. Owing to the difference in speed between the moving sea plates, the strain energy is...More than a half of strong earthquakes in the world are located in shallow depth at the subducting plate boundary in squeezed zones. Owing to the difference in speed between the moving sea plates, the strain energy is accumulated and released cyclically in squeezed zones. Several methods were developed to analyze the medium-and short-term potential of main shocks. These methods can be classified into (1) less data systems using the theory of grey model for earthquake prediction, (2) quasi-periodic systems using earthquake activity analysis, (3) systems of grouped activity using order analysis, and (4) nonlinear systems using back propagation (BP) of neural network for prediction analysis. Based upon these analytic methods, risk maps for the prediction of strong earthquakes can be drawn using the records of strong earthquakes in Taiwan for the past 100 years. These risk maps include (1) a seismic risk map, (2) a loss risk map, (3) a hazard degree map, and (4) a loss degree map. These risk maps make it possible to do a medium-term prediction of main shocks on the 10-year scale.展开更多
Medium-and long-chain triglycerides(MLCT)have been widely concerned.In this study,lauric acid(La)was incorporated into flaxseed(Linum usitatissimum L.)oil(FO,aLna-riched)by lipase-catalyzed acidolysis.The synthesis ef...Medium-and long-chain triglycerides(MLCT)have been widely concerned.In this study,lauric acid(La)was incorporated into flaxseed(Linum usitatissimum L.)oil(FO,aLna-riched)by lipase-catalyzed acidolysis.The synthesis efficiency of four immobilized lipases(Lipozyme RM IM,TL IM,AOAB8 and Novozym 435)was compared,while Lipozyme AOAB8 reaction for 2 h was the best scheme.Further,the optimal conditions for synthesizing structural lipids(aLSLs,rich in aLna and La)were obtained by response surface methodology:the reaction temperature was 44.6℃,substrate molar ratio was 12(La/FO),and enzyme loading was 9.11%.After purification by molecular distillation,the triglycerides(TAGs)of aLSLs contained 75.35% of TAGs withα-linolenic acid(aLna),40.82%of MLCTs with La,and 26.75%(65.53% of the total MLCTs)of TAGs with both aLna and La(ɑ-MLCT).Meanwhile,the content of La and aLna in aLSLs were 22.38%and 39.78%,respectively.The chemical structure and microstructure of aLSLs were similar to FO.In addition,the thermo-oxidative decomposition behavior of aLSLs was significantly improved compared with physical mixture oil.This improvement might be related to the insertion of La and the structure of TAG.In all,this study firstly developed a novel thermo-oxidatively stable MLCT with high levels of aLna and La.展开更多
基金Supported by the China National Science and Technology Major Project(2016ZX05007004,2016ZX05004005)
文摘Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous paleo-uplifts around Central Sichuan, paleo erosion surfaces of the top boundary of Maokou Formation in eastern and southern Sichuan Basin, paleo erosion surfaces of the top boundary of the Leikoupo Formation in central and western Sichuan Basin.
基金supported by the National Natural Science Foundation of China(31601433)Jiangsu Province Natural Science Foundation(BK20140149).
文摘Medium-and long-chain triacylglycerols(MLCT)rich in arachidonic acid(ARA)at sn-2 position were synthesized by a two-step enzymatic method.Firstly,sn-2 monoacylglycerols(MAG)were synthesized at a temperature of 25℃ by enzymatic alcoholysis.The MAG with 69.42%ARA at sn-2 position were obtained by solvent extraction and low temperature solvent crystallization.Secondly,the MLCT rich in ARA at sn-2 position and capric acid(CA)at sn-1,3 positions were produced by enzymatic esterification.Under the optimal conditions(MAG:CA=1:3(mol/mol),0.05 MPa vacuum,8% Lipozyme RM IM,5 h,25℃),the content of triacylglycerol was up to 93.60%.The triacylglycerol in the form of C10:0-C20:4-C10:0(including isomers)was about 40.43%.The ARA contents in the total and sn-2 fatty acid composition of the final product were 32.35%and 51.12%,respectively.MLCT rich in ARA at sn-2 position were successfully produced and the product has the potential application for functional food and infant formula.
文摘More than a half of strong earthquakes in the world are located in shallow depth at the subducting plate boundary in squeezed zones. Owing to the difference in speed between the moving sea plates, the strain energy is accumulated and released cyclically in squeezed zones. Several methods were developed to analyze the medium-and short-term potential of main shocks. These methods can be classified into (1) less data systems using the theory of grey model for earthquake prediction, (2) quasi-periodic systems using earthquake activity analysis, (3) systems of grouped activity using order analysis, and (4) nonlinear systems using back propagation (BP) of neural network for prediction analysis. Based upon these analytic methods, risk maps for the prediction of strong earthquakes can be drawn using the records of strong earthquakes in Taiwan for the past 100 years. These risk maps include (1) a seismic risk map, (2) a loss risk map, (3) a hazard degree map, and (4) a loss degree map. These risk maps make it possible to do a medium-term prediction of main shocks on the 10-year scale.
基金The authors gratefully acknowledge the funding support of Key Project of Science and Technology Innovation 2025 program(2019B10060)the National Natural Science Foundation of China(32072224).
文摘Medium-and long-chain triglycerides(MLCT)have been widely concerned.In this study,lauric acid(La)was incorporated into flaxseed(Linum usitatissimum L.)oil(FO,aLna-riched)by lipase-catalyzed acidolysis.The synthesis efficiency of four immobilized lipases(Lipozyme RM IM,TL IM,AOAB8 and Novozym 435)was compared,while Lipozyme AOAB8 reaction for 2 h was the best scheme.Further,the optimal conditions for synthesizing structural lipids(aLSLs,rich in aLna and La)were obtained by response surface methodology:the reaction temperature was 44.6℃,substrate molar ratio was 12(La/FO),and enzyme loading was 9.11%.After purification by molecular distillation,the triglycerides(TAGs)of aLSLs contained 75.35% of TAGs withα-linolenic acid(aLna),40.82%of MLCTs with La,and 26.75%(65.53% of the total MLCTs)of TAGs with both aLna and La(ɑ-MLCT).Meanwhile,the content of La and aLna in aLSLs were 22.38%and 39.78%,respectively.The chemical structure and microstructure of aLSLs were similar to FO.In addition,the thermo-oxidative decomposition behavior of aLSLs was significantly improved compared with physical mixture oil.This improvement might be related to the insertion of La and the structure of TAG.In all,this study firstly developed a novel thermo-oxidatively stable MLCT with high levels of aLna and La.
