近年来,生物质碳(biochar)作为新型吸附剂被广泛研究。但由于制备biochar的生物质原料和热解温度的不同,使biochar的结构和组成存在差异,从而影响其对污染物的吸附。目前关于biochar的结构和组成的研究还不够全面。因此,结合了能谱与光...近年来,生物质碳(biochar)作为新型吸附剂被广泛研究。但由于制备biochar的生物质原料和热解温度的不同,使biochar的结构和组成存在差异,从而影响其对污染物的吸附。目前关于biochar的结构和组成的研究还不够全面。因此,结合了能谱与光谱分析的手段,对biochar的结构和组成进行了深入的分析。选取木质类(柳树枝条)和草类(水稻秸秆)作为原料,分别在不同热解温度(300,450和600℃)下制得biochars,并对biochars样品进行元素分析、X射线光电子能谱分析(XPS)和固态13 C核磁共振(13 C NMR)研究,以阐明不同热解温度和生物质来源的biochars的结构和组成。结果显示:biochar的H/C,O/C和(O+N)/C的比值随着热解温度的升高而降低;草类biochar比木质类biochar具有更高的灰分含量和表面极性;木质类biochar的矿物主要分布在样品颗粒内部,其表面被有机质覆盖,而草类biochar部分矿物暴露在样品颗粒表面;13 C NMR显示低温制得的biochar主要由芳香碳、脂肪碳、羧基和羰基碳组成,高温制得的biochar主要由芳香碳组成,且低温制得biochars中,木质类biochars比草类biochars含有更高的木质素的残留碳结构,这是由于木质类biochars原材料中含有更高的木质素。展开更多
为明确颗粒有机碳在土壤固碳中的作用机制,对比研究了不同有机培肥土壤颗粒有机碳的结构差异。以单施化肥处理为对照,选择了四种有机物料进行定位培肥试验,利用^(13) C NMR和红外光谱技术对比分析不同有机培肥对土壤颗粒有机碳结构的影...为明确颗粒有机碳在土壤固碳中的作用机制,对比研究了不同有机培肥土壤颗粒有机碳的结构差异。以单施化肥处理为对照,选择了四种有机物料进行定位培肥试验,利用^(13) C NMR和红外光谱技术对比分析不同有机培肥对土壤颗粒有机碳结构的影响。结果表明:颗粒有机碳以脂肪碳和含氧基团为主,脂化度高于75%,含氧官能团含量高于50%;不同有机培肥对土壤颗粒有机碳结构的影响差异性显著,树叶培肥在提高颗粒有机碳芳香度的同时,亲水性也大幅度提高,比单施化肥处理(对照)提高了0.78%;短期内,牛粪、秸秆和树叶培肥均可提高土壤颗粒有机碳的芳香度,但从长远角度分析,牛粪和秸秆培肥更利于土壤颗粒有机碳的稳定,尤其是秸秆培肥,其颗粒有机碳的芳香度分别比对照和牛粪培肥高0.35%和0.11%,而亲水性远低于二者;红外光谱与核磁分析的结果基本一致,红外光谱可用于大量样品的颗粒有机碳结构初步筛选。展开更多
A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear reg...A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.展开更多
Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPM...Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPMAS-^(13)C-NMR)and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)to characterize the chemical components of humic acids.Tomato seed germination index(GI)was determined with the goal of screening the key active components of humic acids.Humic acids had a significantly higher nutrient content,except for the total nitrogen(TN)and the total phosphorus(TP)contents.Humic acids had a higher content of O-CH_(3)/NCH,aromatic C-O and carbonyl C compared to weathered coal,with significantly lower anomeric C,aromatic C and O-alkyl C/alkyl C.There were 611 different compounds identified among the test materials using UHPLC-MS.Humic acids also had a significantly higher GI(158.0%and 153.1%)than weathered coal(85.5%).The organic matter(OM),TP and available potassium(AK)contents in humic acids were significantly positively correlated with GI,and available phosphorus(AP)was significantly negatively correlated.Among the carbon components,O-CH3/NCH,aromatic C-O and O-alkyl C/alkyl C were significantly positively correlated with GI,while anomeric C was significantly negatively correlated.Furthermore,among the top 10 positive and five negative correlation compounds,lipids and lipid-like molecules[armexifolin,boviquinone 4,3-methyladipic acid,lxocarpalactone A,monic acid,DG(20:1(11Z)/18:4(6Z,9Z,12Z,15Z)/0:0),and brassinolide]and organic acids and derivatives(N-acetylglutamic acid,8-hydroxy-5,6-octadienoic acid,acetyl-L-tyrosine,and hydroxyprolyl-methionine)in humic acids might be crucial active components for improving tomato seed germination.The results provided direct evidence for the identification of bioactive molecules of humic acids,and a scientific basis for the precise utilization of bioactive molecular components of humic acids in sustainable agricultural development.展开更多
actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to...actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to produce of 17-α-hydroxyl compound stereoselectively by addition 17-keto steroid with hydrogen cyanide, at the same time, the conditions of this asymmertric reaction were optimized. The titled compound and the intermediate were fully characterized by 1H, one dimension and two dimension 13C-nuclear magnetic resonance, and infrared spectrum. The results show that the rate of 17-α-hydroxyl compound isomeride is sensitively affected by the solution system and the best volume ratio of CH3OH to H2O is 36%. After the carbonyl and hydroxyl groups were protected by ethylenediol and vinyl butyl ether respectively, organometallic addition to CN group with CH3Li, androstance compound was converted to pregnane compound. After removing the protective groups by a mild hydrolytic procedure with high yield, the titled compound was obtained by esterified the above intermidiate. The new pathway gives a good purity of 98% as determined by high performance liquid chromatography.展开更多
从北京通州地区3个河流沉积物和天津渤海湾地区4个土壤样品中提取胡敏酸(HA)和非水解碳(NHC),并进行了元素分析、X射线光电子能谱分析(XPS)、傅里叶变换红外光谱(FTIR)和固态13 C核磁共振(13 C NMR)等一系列定性定量的研究。结果显示:...从北京通州地区3个河流沉积物和天津渤海湾地区4个土壤样品中提取胡敏酸(HA)和非水解碳(NHC),并进行了元素分析、X射线光电子能谱分析(XPS)、傅里叶变换红外光谱(FTIR)和固态13 C核磁共振(13 C NMR)等一系列定性定量的研究。结果显示:同一来源的NHC中H/C和O/C比值低于HA的H/C和O/C比值;NHC和HA表面含氧官能团的含量分别为7.6%～10.7%,40.9%～46.7%;13 C NMR和FTIR显示NHC主要由脂肪碳和芳香碳组成;从土壤中比从沉积物中提取的NHC的芳香度高。研究结果表明,与HA相比,NHC的热成熟度高,疏水性强。展开更多
文摘近年来,生物质碳(biochar)作为新型吸附剂被广泛研究。但由于制备biochar的生物质原料和热解温度的不同,使biochar的结构和组成存在差异,从而影响其对污染物的吸附。目前关于biochar的结构和组成的研究还不够全面。因此,结合了能谱与光谱分析的手段,对biochar的结构和组成进行了深入的分析。选取木质类(柳树枝条)和草类(水稻秸秆)作为原料,分别在不同热解温度(300,450和600℃)下制得biochars,并对biochars样品进行元素分析、X射线光电子能谱分析(XPS)和固态13 C核磁共振(13 C NMR)研究,以阐明不同热解温度和生物质来源的biochars的结构和组成。结果显示:biochar的H/C,O/C和(O+N)/C的比值随着热解温度的升高而降低;草类biochar比木质类biochar具有更高的灰分含量和表面极性;木质类biochar的矿物主要分布在样品颗粒内部,其表面被有机质覆盖,而草类biochar部分矿物暴露在样品颗粒表面;13 C NMR显示低温制得的biochar主要由芳香碳、脂肪碳、羧基和羰基碳组成,高温制得的biochar主要由芳香碳组成,且低温制得biochars中,木质类biochars比草类biochars含有更高的木质素的残留碳结构,这是由于木质类biochars原材料中含有更高的木质素。
基金Jilin Province Science and Technology Department Major Technical Special Bidding Projects(20150203004NY)National Key R&D Projects(2017YFD0201801)
文摘为明确颗粒有机碳在土壤固碳中的作用机制,对比研究了不同有机培肥土壤颗粒有机碳的结构差异。以单施化肥处理为对照,选择了四种有机物料进行定位培肥试验,利用^(13) C NMR和红外光谱技术对比分析不同有机培肥对土壤颗粒有机碳结构的影响。结果表明:颗粒有机碳以脂肪碳和含氧基团为主,脂化度高于75%,含氧官能团含量高于50%;不同有机培肥对土壤颗粒有机碳结构的影响差异性显著,树叶培肥在提高颗粒有机碳芳香度的同时,亲水性也大幅度提高,比单施化肥处理(对照)提高了0.78%;短期内,牛粪、秸秆和树叶培肥均可提高土壤颗粒有机碳的芳香度,但从长远角度分析,牛粪和秸秆培肥更利于土壤颗粒有机碳的稳定,尤其是秸秆培肥,其颗粒有机碳的芳香度分别比对照和牛粪培肥高0.35%和0.11%,而亲水性远低于二者;红外光谱与核磁分析的结果基本一致,红外光谱可用于大量样品的颗粒有机碳结构初步筛选。
基金Projects(20775010, 21075011) supported by the National Natural Science Foundation of ChinaProject(2008AA05Z405) supported by the National High-tech Research and Development Program of China+2 种基金Project(09JJ3016) supported by the Natural Science Foundation of Hunan Province, ChinaProject(09C066) supported by the Scientific Research Fund of Hunan Provincial Education Department, ChinaProject(2010CL01) supported by the Foundation of Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, China
文摘A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.
基金Supported by the National Natural Science Foundation of China(42207371)the Technological Project of Jiangsu Vocational College of Agriculture and Forestry(2021kj17)+1 种基金Yafu Technology Innovation and Service Major Project of Jiangsu Vocational College of Agriculture and Forestry(2024kj01)Key Research Projects of Jiangsu Vocational College of Agriculture and Forestry(2023kj14)。
文摘Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPMAS-^(13)C-NMR)and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)to characterize the chemical components of humic acids.Tomato seed germination index(GI)was determined with the goal of screening the key active components of humic acids.Humic acids had a significantly higher nutrient content,except for the total nitrogen(TN)and the total phosphorus(TP)contents.Humic acids had a higher content of O-CH_(3)/NCH,aromatic C-O and carbonyl C compared to weathered coal,with significantly lower anomeric C,aromatic C and O-alkyl C/alkyl C.There were 611 different compounds identified among the test materials using UHPLC-MS.Humic acids also had a significantly higher GI(158.0%and 153.1%)than weathered coal(85.5%).The organic matter(OM),TP and available potassium(AK)contents in humic acids were significantly positively correlated with GI,and available phosphorus(AP)was significantly negatively correlated.Among the carbon components,O-CH3/NCH,aromatic C-O and O-alkyl C/alkyl C were significantly positively correlated with GI,while anomeric C was significantly negatively correlated.Furthermore,among the top 10 positive and five negative correlation compounds,lipids and lipid-like molecules[armexifolin,boviquinone 4,3-methyladipic acid,lxocarpalactone A,monic acid,DG(20:1(11Z)/18:4(6Z,9Z,12Z,15Z)/0:0),and brassinolide]and organic acids and derivatives(N-acetylglutamic acid,8-hydroxy-5,6-octadienoic acid,acetyl-L-tyrosine,and hydroxyprolyl-methionine)in humic acids might be crucial active components for improving tomato seed germination.The results provided direct evidence for the identification of bioactive molecules of humic acids,and a scientific basis for the precise utilization of bioactive molecular components of humic acids in sustainable agricultural development.
文摘actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to produce of 17-α-hydroxyl compound stereoselectively by addition 17-keto steroid with hydrogen cyanide, at the same time, the conditions of this asymmertric reaction were optimized. The titled compound and the intermediate were fully characterized by 1H, one dimension and two dimension 13C-nuclear magnetic resonance, and infrared spectrum. The results show that the rate of 17-α-hydroxyl compound isomeride is sensitively affected by the solution system and the best volume ratio of CH3OH to H2O is 36%. After the carbonyl and hydroxyl groups were protected by ethylenediol and vinyl butyl ether respectively, organometallic addition to CN group with CH3Li, androstance compound was converted to pregnane compound. After removing the protective groups by a mild hydrolytic procedure with high yield, the titled compound was obtained by esterified the above intermidiate. The new pathway gives a good purity of 98% as determined by high performance liquid chromatography.
文摘从北京通州地区3个河流沉积物和天津渤海湾地区4个土壤样品中提取胡敏酸(HA)和非水解碳(NHC),并进行了元素分析、X射线光电子能谱分析(XPS)、傅里叶变换红外光谱(FTIR)和固态13 C核磁共振(13 C NMR)等一系列定性定量的研究。结果显示:同一来源的NHC中H/C和O/C比值低于HA的H/C和O/C比值;NHC和HA表面含氧官能团的含量分别为7.6%～10.7%,40.9%～46.7%;13 C NMR和FTIR显示NHC主要由脂肪碳和芳香碳组成;从土壤中比从沉积物中提取的NHC的芳香度高。研究结果表明,与HA相比,NHC的热成熟度高,疏水性强。
