Rare earth picrate complexes with the ligand PhenNO, RE(PhenNO)2(pic)3(RE = La, Pr, Nd, Sm to approximately Tb, Er, Y), have been prepared in non-aqueous medium. The complexes were characterized by elementary analysis...Rare earth picrate complexes with the ligand PhenNO, RE(PhenNO)2(pic)3(RE = La, Pr, Nd, Sm to approximately Tb, Er, Y), have been prepared in non-aqueous medium. The complexes were characterized by elementary analysis, molar conductance, IR, Raman, electronic, fluorescence and 1H NMR spectra and TG-DTA techniques.展开更多
New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-p...New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-propylenediimine] （PMBCPR）, poly[4,4＇-methylenebis（cinnamaldehyde） 1,2-phenylenediimine] （PMBCPh）, poly[4,4＇-methylenebis（cinnamaldehyde）meso-stilbenediimine] （PMBCS）, poly[4,4＇-methylenebis（cinnamaldehyde）urea] （PMBCUR）, poly[4,4＇- methylenebis（cinnamaldehyde）semicarbazone] （PMBCSc）, poly[4,4＇-methylenebis（cinnamaldehyde）thiosemicarbazone] （PMBCTSc） and poly[4,4＇-methylenebis（cinnamaldehyde）hydrazone] （PMBCH） were formed by polycondensation of 4,4＇- methylenebis（cinnamaldehyde） with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.展开更多
Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR...Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR spectra, UV spectra, TG-DTA, 1H NMR and 13C NMR spectra. Various analyses indicate that the complexes are of nine-coordinated binuclear structure. The carboxylates are bidentate ligands and the ether oxygen atoms also coordinate to rare earth ions. Three water molecules are crystalline water. In addition, the influence of concentration on the chemical shift has been studied through the 1H NMR spectra of the complex Lu2(EDODA)3·3H2O in different concentrations.展开更多
秸秆深还（Deep application of straw, DAS）是指将玉米秸秆施入土壤亚表层（20～40cm），可以解决秸秆焚烧的问题，同时提高土壤肥力、蓄水能力和作物产量。本文采集了吉林农业大学试验站玉米连作耕地试验田中的秸秆深还土壤和未秸秆...秸秆深还（Deep application of straw, DAS）是指将玉米秸秆施入土壤亚表层（20～40cm），可以解决秸秆焚烧的问题，同时提高土壤肥力、蓄水能力和作物产量。本文采集了吉林农业大学试验站玉米连作耕地试验田中的秸秆深还土壤和未秸秆深还土壤，采用湿筛法将其分为〉2mm、2～0．25mm、0．25～0．053mm和〈0．053mm 4个粒级，定性分析提取胡敏酸（HA），通过元素组成、红外光谱和差热分析研究了秸秆深还对黑土各粒级团聚体中HA结构特征的影响。结果表明：黑土团聚体中的优势粒级为2—0．25mm粒级，优势粒级的团聚体含量和有机碳含量均是表层较亚表层低，DAS有利于优势粒级团聚体的形成，促使优势粒级团聚体中有机碳增多；与亚表层相比，表层各粒级团聚体HA的缩合度、氧化度和热稳定性普遍较低，脂族碳／羧基碳和脂族碳／芳香碳较高；DAS促使土壤表层和亚表层各粒级团聚体中HA的缩合度、氧化度和热稳定性下降，其中表层HA的缩合度降低更明显；而亚表层氧化度和热稳定性的降低幅度较大。表层中HA的分子结构较亚表层的简单、年轻，秸秆深还促使土壤中有机碳含量增加，HA的结构简单化、年轻化。展开更多
秸秆还田主要是覆盖和表层浅施,存在着影响种子发芽生长、土壤升温慢和病虫害增加等问题。秸秆深还（corn stover deep incorporation,CSDI）是指将玉米秸秆施入土壤亚表层（20~40 cm）,不仅能解决秸秆焚烧的问题,还能达到保碳、蓄水、...秸秆还田主要是覆盖和表层浅施,存在着影响种子发芽生长、土壤升温慢和病虫害增加等问题。秸秆深还（corn stover deep incorporation,CSDI）是指将玉米秸秆施入土壤亚表层（20~40 cm）,不仅能解决秸秆焚烧的问题,还能达到保碳、蓄水、培肥、稳产的目的,使秸秆还田得到改善。虽对秸秆深还后胡敏素（Hu）的结构性质有一些研究,但是对秸秆深还后土壤团聚体中Hu的变化还未见报道。探究秸秆深还对土壤腐殖质的影响,可以为如何提高土地肥力、如何利用秸秆深还创建合理耕层提供理论依据。本试验采集于吉林农业大学试验站玉米连作耕地试验田,采用湿筛法将其分为〉2 mm、2~0.25 mm、0.25~0.053 mm和〈0.053 mm 4个粒级并提取Hu,通过元素组成、红外光谱和差热分析研究秸秆深还对团聚体中Hu结构特征的影响。结果表明：用此方法制备的黑土Hu的平均含碳量为721 g kg-1;H/C的平均值为0.776;Hu的缩合度高于相应的HA;秸秆深还促使土壤表层和亚表层团聚体中Hu的氧化度降低,脂族链烃减少,活性结构增多,稳定性降低,Hu的结构趋于简单化、年轻化。展开更多
文摘Rare earth picrate complexes with the ligand PhenNO, RE(PhenNO)2(pic)3(RE = La, Pr, Nd, Sm to approximately Tb, Er, Y), have been prepared in non-aqueous medium. The complexes were characterized by elementary analysis, molar conductance, IR, Raman, electronic, fluorescence and 1H NMR spectra and TG-DTA techniques.
文摘New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-propylenediimine] （PMBCPR）, poly[4,4＇-methylenebis（cinnamaldehyde） 1,2-phenylenediimine] （PMBCPh）, poly[4,4＇-methylenebis（cinnamaldehyde）meso-stilbenediimine] （PMBCS）, poly[4,4＇-methylenebis（cinnamaldehyde）urea] （PMBCUR）, poly[4,4＇- methylenebis（cinnamaldehyde）semicarbazone] （PMBCSc）, poly[4,4＇-methylenebis（cinnamaldehyde）thiosemicarbazone] （PMBCTSc） and poly[4,4＇-methylenebis（cinnamaldehyde）hydrazone] （PMBCH） were formed by polycondensation of 4,4＇- methylenebis（cinnamaldehyde） with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.
文摘Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR spectra, UV spectra, TG-DTA, 1H NMR and 13C NMR spectra. Various analyses indicate that the complexes are of nine-coordinated binuclear structure. The carboxylates are bidentate ligands and the ether oxygen atoms also coordinate to rare earth ions. Three water molecules are crystalline water. In addition, the influence of concentration on the chemical shift has been studied through the 1H NMR spectra of the complex Lu2(EDODA)3·3H2O in different concentrations.
文摘秸秆还田主要是覆盖和表层浅施,存在着影响种子发芽生长、土壤升温慢和病虫害增加等问题。秸秆深还（corn stover deep incorporation,CSDI）是指将玉米秸秆施入土壤亚表层（20~40 cm）,不仅能解决秸秆焚烧的问题,还能达到保碳、蓄水、培肥、稳产的目的,使秸秆还田得到改善。虽对秸秆深还后胡敏素（Hu）的结构性质有一些研究,但是对秸秆深还后土壤团聚体中Hu的变化还未见报道。探究秸秆深还对土壤腐殖质的影响,可以为如何提高土地肥力、如何利用秸秆深还创建合理耕层提供理论依据。本试验采集于吉林农业大学试验站玉米连作耕地试验田,采用湿筛法将其分为〉2 mm、2~0.25 mm、0.25~0.053 mm和〈0.053 mm 4个粒级并提取Hu,通过元素组成、红外光谱和差热分析研究秸秆深还对团聚体中Hu结构特征的影响。结果表明：用此方法制备的黑土Hu的平均含碳量为721 g kg-1;H/C的平均值为0.776;Hu的缩合度高于相应的HA;秸秆深还促使土壤表层和亚表层团聚体中Hu的氧化度降低,脂族链烃减少,活性结构增多,稳定性降低,Hu的结构趋于简单化、年轻化。
