China’s Fengyun-3D meteorological satellite launched in December 2016 carries the high-resolution greenhouse-gases absorption spectrometer(GAS)aimed at providing global observations of carbon dioxide(CO_(2)).To date,...China’s Fengyun-3D meteorological satellite launched in December 2016 carries the high-resolution greenhouse-gases absorption spectrometer(GAS)aimed at providing global observations of carbon dioxide(CO_(2)).To date,GAS is one of the few instruments measuring CO_(2) from the near-infrared spectrum.On orbit,the oxygen(O_(2))A band suffers a disturbance,and the signal-to-noise ratio(SNR)is significantly lower than the nominal specification.This leads to difficulties in the retrieval of surface pressure and hence a degradation of the retrieval of the column-averaged CO_(2) dry air mole fraction(XCO_(2))if a full physics retrieval algorithm is used.Thus,a fast CO_(2) inverse method,named semi-physical statistical algorithm,was developed to overcome this deficiency.The instrument characteristics,the semi-physical statistical algorithm,and the results of comparison with ground-based measurements over land were introduced in this paper.XCO_(2) can be obtained from three bands,namely,the O_(2) A,weak CO_(2),and strong CO_(2) bands,with compensation from the Medium Resolution Spectral Imager-2(MERSI-2)products,ECMWF Reanaly-sis v5(ERA-5)data,and Total Carbon Column Observing Network(TCCON)data.The eigenvectors of covariance matrices and the least square fits were used to derive retrieval coefficients and yield cloud-free solutions.In addition to the GAS radiance,some key factors necessary for the accurate estimations of XCO_(2) were also taken as input information(e.g.,air mass,surface pressure,and a priori XCO_(2)).The global GAS XCO_(2) restricted over land was compared against the simultaneously collocated observations from TCCON.The retrieval algorithm can mitigate the issue caused by the low SNR of the O_(2) A band to a certain extent.Overall,through site-by-site comparisons,GAS XCO_(2) agreed well with the average precision(1σ)of 1.52 ppm and bias of−0.007 ppm.The seasonal variation trends of GAS XCO_(2) can be clearly seen at TCCON sites on the 1-yr timescale.展开更多
Background:Type 2 diabetes(T2D)has already become a global pandemic.As its simple,rapid,economical,and relatively non-invasive,metabolic markers have become a method for T2D diagnosis.However,region,race,and diet all ...Background:Type 2 diabetes(T2D)has already become a global pandemic.As its simple,rapid,economical,and relatively non-invasive,metabolic markers have become a method for T2D diagnosis.However,region,race,and diet all affect the metabolism of the body.The purpose of current study is to explore the differences of metabolites in T2D patients from regions.Methods:We recruited 103 T2D patients in two clinical centers,including 52 T2D patients from Beijing(T2D_(B))and 51 T2D patients from Kaifeng(T2D_(K)).The serum samples from T2D patients were analyzed using high-resolution mass spectrometer.After screened using univariate and multivariate analysis,the differential metabolites were identified.Moreover,to reveal biological information,we performed pathway analysis with the differential metabolites.Results:Thirty-six differential metabolites were identified,including 16 metabolites were higher concentrations while 20 metabolites were lower concentrations in the serum of T2D_(B) patients than T2D_(K) patients.There were higher serum concentrations of L-phenylalanine,4-methyl-2-oxovaleric acid,L-carnitine,decanoylcarnitine,9-decenoylcarnitine and sphinganine in T2D_(B) patients,in which decanoylcarnitine in T2D_(B) patients was up to 35-fold higher than T2D_(K) patients.While there were lower concentrations of L-valine,L-isoleucine,arachidonic acid,oleic acid,16-hydroxyhexadecanoic acid,lysophosphatidylcholine(18:0)and 1-Phenylethylamine in T2D_(B) patients,in which 1-phenylethylamine in T2D_(B) patients was decreased to 0.45-fold lower than T2D_(K) patients.The reason for the differences might be that phosphatidylethanolamine biosynthesis,phosphatidylcholine biosynthesis,valine,leucine and isoleucine degradation,and beta-oxidation of very long chain fatty acids were different in T2D_(B) patients and in T2D_(K) patients.Conclusion:Metabolites from different pathways are independently related to regions,providing valuable insight and potential for the diagnosis and treatment of T2D.展开更多
基于有机胺吸收剂的化学吸收法能够有效捕集船舶烟气中的CO_(2),但吸收剂降解失效、挥发泄漏会造成严重的环境问题。虽然傅里叶红外光谱仪能够实时监测挥发的有机胺体积分数,但受限于高饱和蒸气压有机胺类蒸气难标定问题,对胺类体积分...基于有机胺吸收剂的化学吸收法能够有效捕集船舶烟气中的CO_(2),但吸收剂降解失效、挥发泄漏会造成严重的环境问题。虽然傅里叶红外光谱仪能够实时监测挥发的有机胺体积分数,但受限于高饱和蒸气压有机胺类蒸气难标定问题,对胺类体积分数的实际监测精度较低。对此,设计两种傅里叶红外光谱仪中高饱和蒸气压有机胺蒸气体积分数标定方法,分别为固定比例校准算法和基于循环神经网络的序列映射法。结果表明,相较于固定比例法,基于循环神经网络的非线性序列映射法能够实现更好的校准性能,平均绝对误差下降了81.57%,均方误差下降了70.05%,可有效反映船舶碳捕集与封存(carbon capture and storage,CCS)系统对大气环境的影响。展开更多
基金Supported by the Civil Aerospace Technology Pre Research Project(D040301)。
文摘China’s Fengyun-3D meteorological satellite launched in December 2016 carries the high-resolution greenhouse-gases absorption spectrometer(GAS)aimed at providing global observations of carbon dioxide(CO_(2)).To date,GAS is one of the few instruments measuring CO_(2) from the near-infrared spectrum.On orbit,the oxygen(O_(2))A band suffers a disturbance,and the signal-to-noise ratio(SNR)is significantly lower than the nominal specification.This leads to difficulties in the retrieval of surface pressure and hence a degradation of the retrieval of the column-averaged CO_(2) dry air mole fraction(XCO_(2))if a full physics retrieval algorithm is used.Thus,a fast CO_(2) inverse method,named semi-physical statistical algorithm,was developed to overcome this deficiency.The instrument characteristics,the semi-physical statistical algorithm,and the results of comparison with ground-based measurements over land were introduced in this paper.XCO_(2) can be obtained from three bands,namely,the O_(2) A,weak CO_(2),and strong CO_(2) bands,with compensation from the Medium Resolution Spectral Imager-2(MERSI-2)products,ECMWF Reanaly-sis v5(ERA-5)data,and Total Carbon Column Observing Network(TCCON)data.The eigenvectors of covariance matrices and the least square fits were used to derive retrieval coefficients and yield cloud-free solutions.In addition to the GAS radiance,some key factors necessary for the accurate estimations of XCO_(2) were also taken as input information(e.g.,air mass,surface pressure,and a priori XCO_(2)).The global GAS XCO_(2) restricted over land was compared against the simultaneously collocated observations from TCCON.The retrieval algorithm can mitigate the issue caused by the low SNR of the O_(2) A band to a certain extent.Overall,through site-by-site comparisons,GAS XCO_(2) agreed well with the average precision(1σ)of 1.52 ppm and bias of−0.007 ppm.The seasonal variation trends of GAS XCO_(2) can be clearly seen at TCCON sites on the 1-yr timescale.
基金supported by the National Natural Science Foundation of China(82130112)Capital’s Funds for Health Improvement and Research(CFH2024-2-1193)the Youth Beijing Scholar(2022-051).
文摘Background:Type 2 diabetes(T2D)has already become a global pandemic.As its simple,rapid,economical,and relatively non-invasive,metabolic markers have become a method for T2D diagnosis.However,region,race,and diet all affect the metabolism of the body.The purpose of current study is to explore the differences of metabolites in T2D patients from regions.Methods:We recruited 103 T2D patients in two clinical centers,including 52 T2D patients from Beijing(T2D_(B))and 51 T2D patients from Kaifeng(T2D_(K)).The serum samples from T2D patients were analyzed using high-resolution mass spectrometer.After screened using univariate and multivariate analysis,the differential metabolites were identified.Moreover,to reveal biological information,we performed pathway analysis with the differential metabolites.Results:Thirty-six differential metabolites were identified,including 16 metabolites were higher concentrations while 20 metabolites were lower concentrations in the serum of T2D_(B) patients than T2D_(K) patients.There were higher serum concentrations of L-phenylalanine,4-methyl-2-oxovaleric acid,L-carnitine,decanoylcarnitine,9-decenoylcarnitine and sphinganine in T2D_(B) patients,in which decanoylcarnitine in T2D_(B) patients was up to 35-fold higher than T2D_(K) patients.While there were lower concentrations of L-valine,L-isoleucine,arachidonic acid,oleic acid,16-hydroxyhexadecanoic acid,lysophosphatidylcholine(18:0)and 1-Phenylethylamine in T2D_(B) patients,in which 1-phenylethylamine in T2D_(B) patients was decreased to 0.45-fold lower than T2D_(K) patients.The reason for the differences might be that phosphatidylethanolamine biosynthesis,phosphatidylcholine biosynthesis,valine,leucine and isoleucine degradation,and beta-oxidation of very long chain fatty acids were different in T2D_(B) patients and in T2D_(K) patients.Conclusion:Metabolites from different pathways are independently related to regions,providing valuable insight and potential for the diagnosis and treatment of T2D.
文摘基于有机胺吸收剂的化学吸收法能够有效捕集船舶烟气中的CO_(2),但吸收剂降解失效、挥发泄漏会造成严重的环境问题。虽然傅里叶红外光谱仪能够实时监测挥发的有机胺体积分数,但受限于高饱和蒸气压有机胺类蒸气难标定问题,对胺类体积分数的实际监测精度较低。对此,设计两种傅里叶红外光谱仪中高饱和蒸气压有机胺蒸气体积分数标定方法,分别为固定比例校准算法和基于循环神经网络的序列映射法。结果表明,相较于固定比例法,基于循环神经网络的非线性序列映射法能够实现更好的校准性能,平均绝对误差下降了81.57%,均方误差下降了70.05%,可有效反映船舶碳捕集与封存(carbon capture and storage,CCS)系统对大气环境的影响。
