In an effort to utilize NMR technique for the analysis of the structural components of wood and biomasses such as lignin, we made a comparative study of lignin contents of several types of lignocellulosie materials bo...In an effort to utilize NMR technique for the analysis of the structural components of wood and biomasses such as lignin, we made a comparative study of lignin contents of several types of lignocellulosie materials both before and after enzymatic hydrolyses. To this end, Eucalyptus Globulus, Norway spruce thermomeehanieal pulp（TMP） corn stover and Eucalyptus kraft pulp were ball-milled and treated with cellulase to prepare materials with high lignin contents. These materials were analyzed via ^31p NMR in ionic liquids. The results show that the contents of various functional groups for the lignocellulosic materials after enzymatic hydrolyses are generally in agreement with those from their corresponding enzymatic mild acidolysis liginins（EMALs）, indicating that ^31p NMR analysis of lignocellulosic materials in ionic liquids is a promising method for quantitative characterization of lignocellulosic materials.展开更多
Organothiophosphoryl polyoxotungstate derivatives α-C_6H_(11)P(S)]_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were obtained by the reactions of the monovacant α-_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were...Organothiophosphoryl polyoxotungstate derivatives α-C_6H_(11)P(S)]_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were obtained by the reactions of the monovacant α-_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were obtained by the reactions of the monovacant α-[X^(n+)W_(11)O_(39)]^((12-n)-)(X=P, Si, Ge, Ga) anions with electrophilic C_6H_(11)P(S)Cl_2 in acetonitrile. These new organic-inorganic hybrid anions were characterized by elemental analyses, IR, (()^(31)P) and (()^(183)W) NMR spectrometries. The six-line ()^(183)W NMR spectrum indicates that [C_6H_(11)P(S)]_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) anions possess true C_s symmetry in acetonitrile. According to the spectroscopic observation and the chemical analyses, it is known that each of the hybrid anions consists of an α-[XW_(11)O_(39)] framework on which two equivalent C_6H_(11)P(S) groups are grafted through P-O-W bridges.展开更多
Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus （P） composition and phosphatase activities. However, these effects are poody understood. This study used...Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus （P） composition and phosphatase activities. However, these effects are poody understood. This study used NaOH-EDTA extraction and solution ^31P nuclear magnetic resonance （NMR） spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase （AcP）, phosphodiesterase （PD） and inorganic pyrophosphatase （IPP）, in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients （i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m）. The results show that total P （TP）, organic P （OP）, OP/TP, NaOH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500-2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP （73%0-83%） with a large proportion of monoesters （65%0-72%）, whereas inorganic P is present in lower proportions （17%-27%）. The activity of AcP is significantly positively correlated with the contents of soil OP, total carbon （TC）, total nitrogen （TN）, and TP （P 〈 0.05）, indicating that the AcP is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil pH. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and AcP may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.展开更多
The extractive separation properties and the extractive regularity of the lanthanide elements by five di(2-ethylhexyl)alkyl phosphonates with various alkyl structure:di(2-ethylhexyl)chloromethyl phosphonate CH_2ClP(O)...The extractive separation properties and the extractive regularity of the lanthanide elements by five di(2-ethylhexyl)alkyl phosphonates with various alkyl structure:di(2-ethylhexyl)chloromethyl phosphonate CH_2ClP(O) (OC_8H_(17)-i)_2(1),di(2-ethylhexyl)β-chloroethyl phosphonate ClCH_2CH_2P(O) (OC_8H_(17)-i)_2 (2),di(2-ethylhexyl)α-chloroethyl phosphonate CH_3CHClP(O)(OC_8H_(17)-i)_2 (3),and corresponding di(2-ethylhexyl)methyl phosphonate CH_3P(O)(OC_8H_(17)-i)_2 (4),di(2-ethylhexyl)ethyl phosphonate C_2H_5P(O) (OC_8H_(17)-i)_2 (5),in nitrate system have been studied.The coordination compounds were prepared. The structure of these extractants and their coordination compounds were further explored by IR and ^(31)P NMR spectra.展开更多
The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino)(methylthio)phosphenium cation 1.has been prepared by treatument of the (dimethylamino)(methylthio) chlorophosphines 2 wih the stoichiometri q...The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino)(methylthio)phosphenium cation 1.has been prepared by treatument of the (dimethylamino)(methylthio) chlorophosphines 2 wih the stoichiometri quantity of AlCl3 in CH2Cl2 solution, and charcterized by 1H 13C 27Al and 31P NMR spectroseopy展开更多
The linear relationship between the chemical shift of the resenant nucleus and the localvan der Waals steric energy calculated by molecular mechanics with MM2 force field wasextended to various organophosphorus compou...The linear relationship between the chemical shift of the resenant nucleus and the localvan der Waals steric energy calculated by molecular mechanics with MM2 force field wasextended to various organophosphorus compounds including alkyl-phosphates, -phosphonates,-phosphinates as well as -phosphine oxides. The conformational equilibria of a series of alkylO,O-1,3--propylene-and O, O-1,4-butylenephosphonates were studied by the molecular mechanicscalculations and the dynamic ^(31)P NMR spectroscopic method. As shown by these experimentaldata, the former existed in a chair form, and the latter in a twist boat form with an equatorialalkyl group in both configurations, either in gaseous state or in non-polar solvent.展开更多
In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The...In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The results showed synchronous temporal changes in the sediment OP and OC contents with the development of ABs.In addition,there was a significant positive correlation between the sediment OP and OC(p<0.01),suggesting simultaneous deposition and consumption during the ABs outbreak.The sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs decline.These temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak,even though algae are an important source of organic matter in sediments.The depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs outbreak.The obtained results revealed significant differences in the sediment OC and OP contents between the months(p<0.05).In addition,OP in the sediments was dominated by orthophosphate diester(phospholipids and DNA-P)and orthophosphate monoester during the ABs outbreak and decline,respectively.The active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period,demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.展开更多
基金Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education, China and the Scientific and Technological Development Programs of of Beijing Municipal Education Commission (No.KM201010011004)
文摘In an effort to utilize NMR technique for the analysis of the structural components of wood and biomasses such as lignin, we made a comparative study of lignin contents of several types of lignocellulosie materials both before and after enzymatic hydrolyses. To this end, Eucalyptus Globulus, Norway spruce thermomeehanieal pulp（TMP） corn stover and Eucalyptus kraft pulp were ball-milled and treated with cellulase to prepare materials with high lignin contents. These materials were analyzed via ^31p NMR in ionic liquids. The results show that the contents of various functional groups for the lignocellulosic materials after enzymatic hydrolyses are generally in agreement with those from their corresponding enzymatic mild acidolysis liginins（EMALs）, indicating that ^31p NMR analysis of lignocellulosic materials in ionic liquids is a promising method for quantitative characterization of lignocellulosic materials.
基金Supported by the Natural Science Foundation of L iaoning Province of China(No.2 0 0 32 10 4 )
文摘Organothiophosphoryl polyoxotungstate derivatives α-C_6H_(11)P(S)]_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were obtained by the reactions of the monovacant α-_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) were obtained by the reactions of the monovacant α-[X^(n+)W_(11)O_(39)]^((12-n)-)(X=P, Si, Ge, Ga) anions with electrophilic C_6H_(11)P(S)Cl_2 in acetonitrile. These new organic-inorganic hybrid anions were characterized by elemental analyses, IR, (()^(31)P) and (()^(183)W) NMR spectrometries. The six-line ()^(183)W NMR spectrum indicates that [C_6H_(11)P(S)]_2X^(n+)W_(11)O_(39)^((8-n)-)(X=P, Si, Ge, Ga) anions possess true C_s symmetry in acetonitrile. According to the spectroscopic observation and the chemical analyses, it is known that each of the hybrid anions consists of an α-[XW_(11)O_(39)] framework on which two equivalent C_6H_(11)P(S) groups are grafted through P-O-W bridges.
基金National Natural Science Foundation of China(No.41171241)
文摘Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus （P） composition and phosphatase activities. However, these effects are poody understood. This study used NaOH-EDTA extraction and solution ^31P nuclear magnetic resonance （NMR） spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase （AcP）, phosphodiesterase （PD） and inorganic pyrophosphatase （IPP）, in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients （i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m）. The results show that total P （TP）, organic P （OP）, OP/TP, NaOH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500-2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP （73%0-83%） with a large proportion of monoesters （65%0-72%）, whereas inorganic P is present in lower proportions （17%-27%）. The activity of AcP is significantly positively correlated with the contents of soil OP, total carbon （TC）, total nitrogen （TN）, and TP （P 〈 0.05）, indicating that the AcP is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil pH. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and AcP may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.
文摘The extractive separation properties and the extractive regularity of the lanthanide elements by five di(2-ethylhexyl)alkyl phosphonates with various alkyl structure:di(2-ethylhexyl)chloromethyl phosphonate CH_2ClP(O) (OC_8H_(17)-i)_2(1),di(2-ethylhexyl)β-chloroethyl phosphonate ClCH_2CH_2P(O) (OC_8H_(17)-i)_2 (2),di(2-ethylhexyl)α-chloroethyl phosphonate CH_3CHClP(O)(OC_8H_(17)-i)_2 (3),and corresponding di(2-ethylhexyl)methyl phosphonate CH_3P(O)(OC_8H_(17)-i)_2 (4),di(2-ethylhexyl)ethyl phosphonate C_2H_5P(O) (OC_8H_(17)-i)_2 (5),in nitrate system have been studied.The coordination compounds were prepared. The structure of these extractants and their coordination compounds were further explored by IR and ^(31)P NMR spectra.
文摘The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino)(methylthio)phosphenium cation 1.has been prepared by treatument of the (dimethylamino)(methylthio) chlorophosphines 2 wih the stoichiometri quantity of AlCl3 in CH2Cl2 solution, and charcterized by 1H 13C 27Al and 31P NMR spectroseopy
文摘The linear relationship between the chemical shift of the resenant nucleus and the localvan der Waals steric energy calculated by molecular mechanics with MM2 force field wasextended to various organophosphorus compounds including alkyl-phosphates, -phosphonates,-phosphinates as well as -phosphine oxides. The conformational equilibria of a series of alkylO,O-1,3--propylene-and O, O-1,4-butylenephosphonates were studied by the molecular mechanicscalculations and the dynamic ^(31)P NMR spectroscopic method. As shown by these experimentaldata, the former existed in a chair form, and the latter in a twist boat form with an equatorialalkyl group in both configurations, either in gaseous state or in non-polar solvent.
基金jointly sponsored by the National Natural Science Foundation of China(No.41371450)the Natural Science Foundation of Henan(No.222300420418)the Postgraduate Cultivating Innovation and Quality Improvement Action Plan of Henan University(No.SYLYC2022015)。
文摘In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The results showed synchronous temporal changes in the sediment OP and OC contents with the development of ABs.In addition,there was a significant positive correlation between the sediment OP and OC(p<0.01),suggesting simultaneous deposition and consumption during the ABs outbreak.The sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs decline.These temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak,even though algae are an important source of organic matter in sediments.The depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs outbreak.The obtained results revealed significant differences in the sediment OC and OP contents between the months(p<0.05).In addition,OP in the sediments was dominated by orthophosphate diester(phospholipids and DNA-P)and orthophosphate monoester during the ABs outbreak and decline,respectively.The active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period,demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.
