Cloud top pressure(CTP)is one of the critical cloud properties that significantly affects the radiative effect of clouds.Multi-angle polarized sensors can employ polarized bands(490 nm)or O_(2)A-bands(763 and 765 nm)t...Cloud top pressure(CTP)is one of the critical cloud properties that significantly affects the radiative effect of clouds.Multi-angle polarized sensors can employ polarized bands(490 nm)or O_(2)A-bands(763 and 765 nm)to retrieve the CTP.However,the CTP retrieved by the two methods shows inconsistent results in certain cases,and large uncertainties in low and thin cloud retrievals,which may lead to challenges in subsequent applications.This study proposes a synergistic algorithm that considers both O_(2)A-bands and polarized bands using a random forest(RF)model.LiDAR CTP data are used as the true values and the polarized and non-polarized measurements are concatenated to train the RF model to determine CTP.Additionally,through analysis,we proposed that the polarized signal becomes saturated as the cloud optical thickness(COT)increases,necessitating a particular treatment for cases where COT<10 to improve the algorithm's stability.The synergistic method was then applied to the directional polarized camera(DPC)and Polarized and Directionality of the Earth’s Reflectance(POLDER)measurements for evaluation,and the resulting retrieval accuracy of the POLDER-based measurements(RMSEPOLDER=205.176 hPa,RMSEDPC=171.141 hPa,R^(2)POLDER=0.636,R^(2)DPC=0.663,respectively)were higher than that of the MODIS and POLDER Rayleigh pressure measurements.The synergistic algorithm also showed good performance with the application of DPC data.This algorithm is expected to provide data support for atmosphere-related fields as an atmospheric remote sensing algorithm within the Cloud Application for Remote Sensing,Atmospheric Radiation,and Updating Energy(CARE)platform.展开更多
Cloud radiative kernels(CRK)built with radiative transfer models have been widely used to analyze the cloud radiative effect on top of atmosphere(TOA)fluxes,and it is expected that the CRKs would also be useful in the...Cloud radiative kernels(CRK)built with radiative transfer models have been widely used to analyze the cloud radiative effect on top of atmosphere(TOA)fluxes,and it is expected that the CRKs would also be useful in the analyses of surface radiative fluxes,which determines the regional surface temperature change and variability.In this study,CRKs at the surface and TOA were built using the Rapid Radiative Transfer Model(RRTM).Longwave cloud radiative effect(CRE)at the surface is primarily driven by cloud base properties,while TOA CRE is primarily decided by cloud top properties.For this reason,the standard version of surface CRK is a function of latitude,longitude,month,cloud optical thickness(τ)and cloud base pressure(CBP),and the TOA CRK is a function of latitude,longitude,month,τand cloud top pressure(CTP).Considering that the cloud property histograms provided by climate models are functions of CTP instead of CBP at present,the surface CRKs on CBP-τhistograms were converted to CTP-τfields using the statistical relationship between CTP,CBP andτobtained from collocated CloudSat and MODIS observations.For both climate model outputs and satellites observations,the climatology of surface CRE and cloud-induced surface radiative anomalies calculated with the surface CRKs and cloud property histograms are well correlated with those calculated from surface radiative fluxes.The cloud-induced surface radiative anomalies reproduced by surface CRKs and MODIS cloud property histograms are not affected by spurious trends that appear in Clouds and the Earth's Radiant Energy System(CERES)surface irradiances products.展开更多
The high-efficient development of shale oil is one of the urgent problems in the petroleum industry. The technology of CO_(2) enhanced oil recovery(EOR) has shown significant effects in developing shale oil. The effec...The high-efficient development of shale oil is one of the urgent problems in the petroleum industry. The technology of CO_(2) enhanced oil recovery(EOR) has shown significant effects in developing shale oil. The effects of several glycol ether additives with low molecular weight on the interactions between CO_(2) and oil were investigated here. The solubility of glycol ether additive in CO_(2) was firstly characterized. Then,the effects of glycol ether additives on the interfacial tension(IFT) between CO_(2) and hexadecane and the volume expansion and extraction performance between CO_(2) and hexadecane under different pressures was investigated. The experimental results show that diethylene glycol dimethyl ether(DEG), triethylene glycol dimethyl ether(TEG), and tetraethylene glycol dimethyl ether(TTEG) all have low cloud point pressure and high affinity with CO_(2). Under the same mass fraction, DGE has the best effect to reduce the IFT between hexadecane and CO_(2) by more than 30.0%, while an overall reduction of 20.0%-30.0% for TEG and 10.0%-20.0% for TTEG. A new method to measure the extraction and expansion rates has been established and can calculate the swelling factor accurately. After adding 1.0% DEG, the expansion and extraction amounts of CO_(2) for hexadecane are respectively increased to 1.75 times and 2.25 times. The results show that glycol ether additives assisted CO_(2) have potential application for EOR. This study can provide theoretical guidance for the optimization of CO_(2) composite systems for oil displacement.展开更多
Three poly(vinyl acetate)(PVAc)oligomers with controlled molecular weight and narrow molecular distribution are synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization.The effects of the re...Three poly(vinyl acetate)(PVAc)oligomers with controlled molecular weight and narrow molecular distribution are synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization.The effects of the reaction temperature and the added amount of initiator of the PVAc polymerization are discussed.In addition,the phase behavior of the prepared PVAc in pressured CO2 is determined via the cloud point method.The results indicate that the cloud point of PVAc increases with the increase in the molecular weight,the PVAc concentration,and the temperature.The cloud point pressures for the PVAc mass concentration of 0.12%with the molecular weight of 1 550,2 120,and 2 960 g/mol are 13.48,13.83 and 15.43 MPa,respectively,at the temperature of 35℃.It reveals that the solubility of PVAc in ScCO2 at relatively low pressure is remarkably limited.展开更多
This research investigates the role of dispersion of nanoparticles in gas during gas recycling process to improve the gas condensate recovery via altering the carbonate reservoirs wettability.The nanoparticles were sy...This research investigates the role of dispersion of nanoparticles in gas during gas recycling process to improve the gas condensate recovery via altering the carbonate reservoirs wettability.The nanoparticles were synthesized and analyzed using dynamic light scattering(DLS),energy-dispersive X-ray(EDX),and transmission electron microscopy(TEM).After that,the dispersion of nanoparticles in methane was investigated by cloud point pressures measurement.Also,the effectiveness of methane/nanoparticles solutions was assessed through the contact angle experiments and gas recycling process.Based on the cloud point pressures results,the nanoparticles can be dispersed in methane at pressures commensurate with hydrocarbon reservoirs.Gas/nanoparticles single-phase solutions increased the contact angles of gas condensate and n-decane from 12°to 121°and 135.5°,respectively,for fluorinated silica,and to 100.5°and 108°for fluorinated titania.The shift from oil-wet to gas-wet conditions enhanced the recovery factor from 55%to 76%,marking a 21%improvement in gas condensate recovery during gas recycling.Furthermore,the pressure drop ratio decreased by 60%,due to better surface wettability and reduced condensate blockage.Comparative results indicated that the dispersion of fluorinated silica nanoparticles in gas outperformed fluorinated titania in altering wettability.These results emphasize the potential of current new approach,through dispersion of fluorinated nanoparticles in gas;to improve gas condensate recovery during gas recycling,especially in low-permeability carbonate reservoirs.展开更多
基金the National Natural Science Foundation of China(Grant Nos.42025504,No.41905023)National Natural Science Youth Science Foundation(Grant No.41701406)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.:2021122).
文摘Cloud top pressure(CTP)is one of the critical cloud properties that significantly affects the radiative effect of clouds.Multi-angle polarized sensors can employ polarized bands(490 nm)or O_(2)A-bands(763 and 765 nm)to retrieve the CTP.However,the CTP retrieved by the two methods shows inconsistent results in certain cases,and large uncertainties in low and thin cloud retrievals,which may lead to challenges in subsequent applications.This study proposes a synergistic algorithm that considers both O_(2)A-bands and polarized bands using a random forest(RF)model.LiDAR CTP data are used as the true values and the polarized and non-polarized measurements are concatenated to train the RF model to determine CTP.Additionally,through analysis,we proposed that the polarized signal becomes saturated as the cloud optical thickness(COT)increases,necessitating a particular treatment for cases where COT<10 to improve the algorithm's stability.The synergistic method was then applied to the directional polarized camera(DPC)and Polarized and Directionality of the Earth’s Reflectance(POLDER)measurements for evaluation,and the resulting retrieval accuracy of the POLDER-based measurements(RMSEPOLDER=205.176 hPa,RMSEDPC=171.141 hPa,R^(2)POLDER=0.636,R^(2)DPC=0.663,respectively)were higher than that of the MODIS and POLDER Rayleigh pressure measurements.The synergistic algorithm also showed good performance with the application of DPC data.This algorithm is expected to provide data support for atmosphere-related fields as an atmospheric remote sensing algorithm within the Cloud Application for Remote Sensing,Atmospheric Radiation,and Updating Energy(CARE)platform.
基金supported by the National Natural Science Foundation of China(Grant No.NSFC 41875095,42075127).
文摘Cloud radiative kernels(CRK)built with radiative transfer models have been widely used to analyze the cloud radiative effect on top of atmosphere(TOA)fluxes,and it is expected that the CRKs would also be useful in the analyses of surface radiative fluxes,which determines the regional surface temperature change and variability.In this study,CRKs at the surface and TOA were built using the Rapid Radiative Transfer Model(RRTM).Longwave cloud radiative effect(CRE)at the surface is primarily driven by cloud base properties,while TOA CRE is primarily decided by cloud top properties.For this reason,the standard version of surface CRK is a function of latitude,longitude,month,cloud optical thickness(τ)and cloud base pressure(CBP),and the TOA CRK is a function of latitude,longitude,month,τand cloud top pressure(CTP).Considering that the cloud property histograms provided by climate models are functions of CTP instead of CBP at present,the surface CRKs on CBP-τhistograms were converted to CTP-τfields using the statistical relationship between CTP,CBP andτobtained from collocated CloudSat and MODIS observations.For both climate model outputs and satellites observations,the climatology of surface CRE and cloud-induced surface radiative anomalies calculated with the surface CRKs and cloud property histograms are well correlated with those calculated from surface radiative fluxes.The cloud-induced surface radiative anomalies reproduced by surface CRKs and MODIS cloud property histograms are not affected by spurious trends that appear in Clouds and the Earth's Radiant Energy System(CERES)surface irradiances products.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 42090024, 52174049)the Natural Science Foundation of Shandong Province of China (No. ZR2019MEE058)。
文摘The high-efficient development of shale oil is one of the urgent problems in the petroleum industry. The technology of CO_(2) enhanced oil recovery(EOR) has shown significant effects in developing shale oil. The effects of several glycol ether additives with low molecular weight on the interactions between CO_(2) and oil were investigated here. The solubility of glycol ether additive in CO_(2) was firstly characterized. Then,the effects of glycol ether additives on the interfacial tension(IFT) between CO_(2) and hexadecane and the volume expansion and extraction performance between CO_(2) and hexadecane under different pressures was investigated. The experimental results show that diethylene glycol dimethyl ether(DEG), triethylene glycol dimethyl ether(TEG), and tetraethylene glycol dimethyl ether(TTEG) all have low cloud point pressure and high affinity with CO_(2). Under the same mass fraction, DGE has the best effect to reduce the IFT between hexadecane and CO_(2) by more than 30.0%, while an overall reduction of 20.0%-30.0% for TEG and 10.0%-20.0% for TTEG. A new method to measure the extraction and expansion rates has been established and can calculate the swelling factor accurately. After adding 1.0% DEG, the expansion and extraction amounts of CO_(2) for hexadecane are respectively increased to 1.75 times and 2.25 times. The results show that glycol ether additives assisted CO_(2) have potential application for EOR. This study can provide theoretical guidance for the optimization of CO_(2) composite systems for oil displacement.
基金The Natural Science Foundation of Jiangsu Province(No.BK20130602)the Applied Basic Research Program of Suzhou(No.SYG201836)the Project of the Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘Three poly(vinyl acetate)(PVAc)oligomers with controlled molecular weight and narrow molecular distribution are synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization.The effects of the reaction temperature and the added amount of initiator of the PVAc polymerization are discussed.In addition,the phase behavior of the prepared PVAc in pressured CO2 is determined via the cloud point method.The results indicate that the cloud point of PVAc increases with the increase in the molecular weight,the PVAc concentration,and the temperature.The cloud point pressures for the PVAc mass concentration of 0.12%with the molecular weight of 1 550,2 120,and 2 960 g/mol are 13.48,13.83 and 15.43 MPa,respectively,at the temperature of 35℃.It reveals that the solubility of PVAc in ScCO2 at relatively low pressure is remarkably limited.
文摘This research investigates the role of dispersion of nanoparticles in gas during gas recycling process to improve the gas condensate recovery via altering the carbonate reservoirs wettability.The nanoparticles were synthesized and analyzed using dynamic light scattering(DLS),energy-dispersive X-ray(EDX),and transmission electron microscopy(TEM).After that,the dispersion of nanoparticles in methane was investigated by cloud point pressures measurement.Also,the effectiveness of methane/nanoparticles solutions was assessed through the contact angle experiments and gas recycling process.Based on the cloud point pressures results,the nanoparticles can be dispersed in methane at pressures commensurate with hydrocarbon reservoirs.Gas/nanoparticles single-phase solutions increased the contact angles of gas condensate and n-decane from 12°to 121°and 135.5°,respectively,for fluorinated silica,and to 100.5°and 108°for fluorinated titania.The shift from oil-wet to gas-wet conditions enhanced the recovery factor from 55%to 76%,marking a 21%improvement in gas condensate recovery during gas recycling.Furthermore,the pressure drop ratio decreased by 60%,due to better surface wettability and reduced condensate blockage.Comparative results indicated that the dispersion of fluorinated silica nanoparticles in gas outperformed fluorinated titania in altering wettability.These results emphasize the potential of current new approach,through dispersion of fluorinated nanoparticles in gas;to improve gas condensate recovery during gas recycling,especially in low-permeability carbonate reservoirs.
