Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the ...Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the increase of biological organic fertilizer would significantly improve soil nutrient supplying capacity.Compared with conventional fertilization,the contents of reducing sugar,total sugar and starch in different parts of tobaccos which were applied with biological organic fertilizer were closer to standards of excellent tobacco.In the treatment,the ratio of reducing sugar and nicotine in tobacco was more suitable in middle and lower parts of the plant and the contents of total N,nicotine and chlorine in tobacco were lowered,improving tobacco quality.展开更多
A greater part of water-solnble organic substances, accounting for 6070To of the total, could be adsorbedby soils, which included strongly and weekly reducing substances, positively and negatively charged substancesan...A greater part of water-solnble organic substances, accounting for 6070To of the total, could be adsorbedby soils, which included strongly and weekly reducing substances, positively and negatively charged substancesand substances containing amido. There existed a tendency of decrease in adsorption of the negativelycharged organic substances by the soil from South China to North China, with expression as Coulombianadsorption. A simultaneous reduction of iron and manganese appeared with clear voltammetric behavioursupon oxidation of water-soluble organic substances. Complexation of organic ligands with ferrons iron andmanganous manganese was proved by differential pulse voltammetric method, with disappearance of oxidationpeaks of ferrous iron and manganous manganese at 0.00 V and 0.35 V and occurrence of Fe`+-complex andMn￣2+ -complex at 0.75 V and 1.2 V respectively, whose peak potentials shifted backward.展开更多
Changes in acidity of Udic Ferrosols, caused by growth of Choerospondias axillaris (Roxb.) Burtt et Hill, in comparison to wild grass, were investigated for pH distribution in the soil profile, exchangeable acidity, a...Changes in acidity of Udic Ferrosols, caused by growth of Choerospondias axillaris (Roxb.) Burtt et Hill, in comparison to wild grass, were investigated for pH distribution in the soil profile, exchangeable acidity, and cation status in the soil leachate of a simulated leaching experiment. Soils were sampled in profiles at 5 cm intervals to a depth of 100 cm. In the 15-60 cm layer the soils with 10-year old C. axillaris had significantly lower pH (P < 0.05), with the largest difference being 0.41; and in…展开更多
The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and han...The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and hand-plucking. Chemical composition and in vitro organic matter digestibility （IVOMD） of hand-plucked material was determined. From July to October, woody plants are a major component of the sheep diet. Sheep selected 40 woody plants and 21 species of herbaceous. During the dry season, grazing occurred more frequently in the fallows. The most frequent woody species belonged to Elaeis guineensis and Fagara zanthoxyloides. At the rainy season, a high proportion of Panicum maximum and Eleucine indica were sampled. Crude protein was high in woody leaves at the dry season. Crude fibre were more variable in herbaceous than in woody and herbaceous were generally higher in the levels of fibre. Chromolaena odorata, Citrus sinensis, Vitex doniana were very high in IVOMD. Spondias mombin, Moringa oleifera, Persea americana, Psidium guajava, Dialium guineense presented lowest values in IVOMD. Among herbaceous, Andropogon gayanus and Panicum maximum still presented a high value of IVOMD at the dry season. High proteins suggest woody with potential as nitrogen supplements to ruminants fed low quality forage during the dry season.展开更多
The crystal of the title compound with formula C36H44Cl2F3Mo2NO8S2 (Mr = 10002.62) crystallized in monoclinic, space group P21/n, with a = 9.6184(1), b = 22.3476(2), c = 20.7758(2) ?, ( = 90.172(1)(, V = 4465.70(7) ?3...The crystal of the title compound with formula C36H44Cl2F3Mo2NO8S2 (Mr = 10002.62) crystallized in monoclinic, space group P21/n, with a = 9.6184(1), b = 22.3476(2), c = 20.7758(2) ?, ( = 90.172(1)(, V = 4465.70(7) ?3, Z = 4, Dc = 1.491 g/cm3, F(000) = 2032, ( = 0.833 mm－1, Final R = 0.0665 and wR = 0.1650 for 5044 reflections with I >2.0( (I). The crystal structure revealed that the Mo2S2 core is planar, and the trifluoroacetic group acts as a bidentate bridging ligand and coordinates to two Mo atoms forming a five-membered ring plane, in which the Mo-Mo bond distance is 2.9222(9) ? and the O-C-O angle is 131.8(7)展开更多
This study aimed to characterize constituents of phosphorus （P） fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 s...This study aimed to characterize constituents of phosphorus （P） fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 sites through Van Veen grabs. Based on a modified sequential extraction scheme, P fractionation was determined as Fe/Al bound P （Fe/Al-P）, Ca bound P （Ca-P）, solute and re-ductive P （S/R-P） and organic P （OP）. Curve estimation and Pearson product-mo-ment correlation were employed for statistical analysis. [Result] Total P （TP） content ranged from 443 to 774 mg/kg. Inorganic P （IP） was the major component of TP, of which Ca-P was dominated with an average of 51%±9.7%. Average contents of P fractionation were in the fol owing order： Ca-P（51%） 〉 OP（29%） 〉 S/R-P（8%） 〉Fe/Al-P（7%）. The molar ratio of Fe to P was 11 - 20, close to the threshold value of P leaching. [Conclusion] In freshwater shal ow lakes, IP and Ca-P were prone to be relatively high, whereas Fe/Al-P was low compared with deep lakes. Occurrence of spatial y monotonic gradient indicated the primary causation of anthropogenic sources. Imminent sediment P liberation was also expected. Close associations a-mong TP, Fe/Al-P and Ca-P, implying that anthropogenic P was mainly bound to metals in particulates. Significant correlations of TOC and P fractionation highlighted endogenous mechanism and authigenic origin in sediments.展开更多
A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period...A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components （14：0, 16：0, 16：1, 18：1 and 20：5）, and n-alkanes （C16-C23） were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017-0.024 d^-1, 0.049-0.103 d^-1 and 0.011 to 0.069 d-l, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments.展开更多
文摘Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the increase of biological organic fertilizer would significantly improve soil nutrient supplying capacity.Compared with conventional fertilization,the contents of reducing sugar,total sugar and starch in different parts of tobaccos which were applied with biological organic fertilizer were closer to standards of excellent tobacco.In the treatment,the ratio of reducing sugar and nicotine in tobacco was more suitable in middle and lower parts of the plant and the contents of total N,nicotine and chlorine in tobacco were lowered,improving tobacco quality.
文摘A greater part of water-solnble organic substances, accounting for 6070To of the total, could be adsorbedby soils, which included strongly and weekly reducing substances, positively and negatively charged substancesand substances containing amido. There existed a tendency of decrease in adsorption of the negativelycharged organic substances by the soil from South China to North China, with expression as Coulombianadsorption. A simultaneous reduction of iron and manganese appeared with clear voltammetric behavioursupon oxidation of water-soluble organic substances. Complexation of organic ligands with ferrons iron andmanganous manganese was proved by differential pulse voltammetric method, with disappearance of oxidationpeaks of ferrous iron and manganous manganese at 0.00 V and 0.35 V and occurrence of Fe`+-complex andMn￣2+ -complex at 0.75 V and 1.2 V respectively, whose peak potentials shifted backward.
文摘Changes in acidity of Udic Ferrosols, caused by growth of Choerospondias axillaris (Roxb.) Burtt et Hill, in comparison to wild grass, were investigated for pH distribution in the soil profile, exchangeable acidity, and cation status in the soil leachate of a simulated leaching experiment. Soils were sampled in profiles at 5 cm intervals to a depth of 100 cm. In the 15-60 cm layer the soils with 10-year old C. axillaris had significantly lower pH (P < 0.05), with the largest difference being 0.41; and in…
文摘The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and hand-plucking. Chemical composition and in vitro organic matter digestibility （IVOMD） of hand-plucked material was determined. From July to October, woody plants are a major component of the sheep diet. Sheep selected 40 woody plants and 21 species of herbaceous. During the dry season, grazing occurred more frequently in the fallows. The most frequent woody species belonged to Elaeis guineensis and Fagara zanthoxyloides. At the rainy season, a high proportion of Panicum maximum and Eleucine indica were sampled. Crude protein was high in woody leaves at the dry season. Crude fibre were more variable in herbaceous than in woody and herbaceous were generally higher in the levels of fibre. Chromolaena odorata, Citrus sinensis, Vitex doniana were very high in IVOMD. Spondias mombin, Moringa oleifera, Persea americana, Psidium guajava, Dialium guineense presented lowest values in IVOMD. Among herbaceous, Andropogon gayanus and Panicum maximum still presented a high value of IVOMD at the dry season. High proteins suggest woody with potential as nitrogen supplements to ruminants fed low quality forage during the dry season.
文摘The crystal of the title compound with formula C36H44Cl2F3Mo2NO8S2 (Mr = 10002.62) crystallized in monoclinic, space group P21/n, with a = 9.6184(1), b = 22.3476(2), c = 20.7758(2) ?, ( = 90.172(1)(, V = 4465.70(7) ?3, Z = 4, Dc = 1.491 g/cm3, F(000) = 2032, ( = 0.833 mm－1, Final R = 0.0665 and wR = 0.1650 for 5044 reflections with I >2.0( (I). The crystal structure revealed that the Mo2S2 core is planar, and the trifluoroacetic group acts as a bidentate bridging ligand and coordinates to two Mo atoms forming a five-membered ring plane, in which the Mo-Mo bond distance is 2.9222(9) ? and the O-C-O angle is 131.8(7)
基金Supported by the National Natural Science Foundation of China(grant No.41171384,41271414 and 41301529)
文摘This study aimed to characterize constituents of phosphorus （P） fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 sites through Van Veen grabs. Based on a modified sequential extraction scheme, P fractionation was determined as Fe/Al bound P （Fe/Al-P）, Ca bound P （Ca-P）, solute and re-ductive P （S/R-P） and organic P （OP）. Curve estimation and Pearson product-mo-ment correlation were employed for statistical analysis. [Result] Total P （TP） content ranged from 443 to 774 mg/kg. Inorganic P （IP） was the major component of TP, of which Ca-P was dominated with an average of 51%±9.7%. Average contents of P fractionation were in the fol owing order： Ca-P（51%） 〉 OP（29%） 〉 S/R-P（8%） 〉Fe/Al-P（7%）. The molar ratio of Fe to P was 11 - 20, close to the threshold value of P leaching. [Conclusion] In freshwater shal ow lakes, IP and Ca-P were prone to be relatively high, whereas Fe/Al-P was low compared with deep lakes. Occurrence of spatial y monotonic gradient indicated the primary causation of anthropogenic sources. Imminent sediment P liberation was also expected. Close associations a-mong TP, Fe/Al-P and Ca-P, implying that anthropogenic P was mainly bound to metals in particulates. Significant correlations of TOC and P fractionation highlighted endogenous mechanism and authigenic origin in sediments.
基金Supported by the National Natural Science Foundation of China (Nos. 40476038 and 40576039)
文摘A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components （14：0, 16：0, 16：1, 18：1 and 20：5）, and n-alkanes （C16-C23） were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017-0.024 d^-1, 0.049-0.103 d^-1 and 0.011 to 0.069 d-l, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments.
