Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity s...Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly.展开更多
The influence of various water soluble cations(K^+,Na^+,Ca^2+,Mg^2+)on the hydration of calcined flue gas desulphurization gypsum was investigated.The results show that all cations but Ca^2+can accelerate the hydratio...The influence of various water soluble cations(K^+,Na^+,Ca^2+,Mg^2+)on the hydration of calcined flue gas desulphurization gypsum was investigated.The results show that all cations but Ca^2+can accelerate the hydration of bassanite.The final crystal size is not largely influenced by different salts,except for Na^+,where the giant crystal with length of>130μm is observed.Current study clarifies the influence of different ions on the hydration of bassanite,which could provide sufficient guide for the pre-treatment of original flue gas desulphurization gypsum before actual application.展开更多
The application of ionic liquids as alternatives to conventional organic solvents in the extraction process has been investigated. In the present study, fourteen species of imidazolium-based ionic liquids were added i...The application of ionic liquids as alternatives to conventional organic solvents in the extraction process has been investigated. In the present study, fourteen species of imidazolium-based ionic liquids were added into the NaOH （aq） to remove the mercaptans. The influences of anion species and cation alkyl chain length of the imidazolium-based ionic liquids on the performance of mercaptan removal from light oils have been discussed. The efficiency of extraction for mercaptans exhibited the order of [Ac]- 〉 [OH]- [Br]- 〉 [BF4]-. The longer alkyl chain imidazolium-based ionic liquids contributed to enhance desulfurization rate of l-butyl mercaptan. 100% desulfurization rate of l-butyl mercaptan was achieved by the anion of Ac- ionic liquids and NaOH （aq） at a volume ratio of 40：1 （V（oil]：Vfionic liouid）） and a short eouilibrium time within 10 min.展开更多
An attempt was made to preserve mango slices by treating with 2% calcium chloride solution followed by dipping into sugar syrup of different concentrations i.e. 50°, 60° and 70 °Brix respectively. The t...An attempt was made to preserve mango slices by treating with 2% calcium chloride solution followed by dipping into sugar syrup of different concentrations i.e. 50°, 60° and 70 °Brix respectively. The treated slices were subjected for drying in different modes of drying （oven, microwave oven and cabinet tray drying） and analyzed for various physico-chemical and organoleptic quality characteristics. The study revealed that the osmo-air dried slices of mango produced with partial dehydration facilitated by osmotic agent （sugar syrup of 60 °Brix. A fruit： sugar syrup ratio of 1：4 （w/v） for 18 h at 40 ℃ temperature） followed by mechanical drying showed superiority in sensorial quality attributes over other concentrations of ingredients and the rest of the modes of drying. The good quality osmotically dehydrated mango slices could be preserved with maximum retentions of vitamins with better dehydration, rehydration and sensorial quality characteristics.展开更多
NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value i...NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value in the feed of isopropanol （IPA） solution on NaA zeolite membranes was investigated. It was found that both factors exhibited strong influence on the stability of NaA zeolite membranes. A set of pretreatment steps such as pH adjustment and distillation of the IPA solution were proposed to improve stability for pervaporation dehydration. An industrial-scale pervaporation facility with 52 m2 membrane area was built to dehydrate IPA solution from industrial cephalosporin production. The facility was continuously operated at 368-378 K to dehydrate IPA solution from water mass content of 15%-20% to less than 2% with a feed flow rate of 400-500 L·h^-1 and an average water flux of 1-1.5 kg·m^-2·h-1. The successful application of this facility suggested a promising application of NaA zeolite mem-brane for IPA recovery from pharmaceutical production.展开更多
Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficien...Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.展开更多
The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively...The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.展开更多
Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier w...Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions：salt concentration 20%-30%,operation tempera-ture 95-100 °C,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.展开更多
Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medla...Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medlars in sucrose solution. The independent variables of osmotic dehydration were temperature （25-65 ℃）, processing time （20-240 min）, sugar concentration （45%-65% w/w） and blanching time （0-180 s）. The optimum conditions were found to be： temperature = 55 ℃, time = 180 min, concentration = 60° Brix and blanching time = 30 s. At this optimum point, water loss, weight reduction and solid gain were found to be 74.12% and 7.136%, respectively.展开更多
We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of t...We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of the naturally occurring2′-deoxyguanosine(dG).Unlike the native dG,the UVabsorption ofSedG is significantly influenced by the pH of the aqueous solution.Moreover,SedG is fluorescent at the physiological pH and exhibits pH-dependent fluorescence in aqueous solutions.Furthermore,SedG has noticeable fluorescence in non-aqueous solutions,indicating its sensitivity to environmental changes.This is the first time a fluorescent nucleoside by single-atom alteration has been observed.Fluorescent nucleosides modified by a single atom have great potential as molecular probes with minimal perturbations to investigate nucleoside interactions with proteins,such as membrane-transporter proteins.展开更多
文摘Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly.
基金supported by the National Natural Science Foundation of China(No.51473152)Scientific research foundation for Young Talents from Fujian Provincial Department of Education(No.JT180494)+2 种基金Start-up Foundation for Advanced Talents in Sanming University(No.18YG07)Industry-University-Research Cooperation Fund from Sanming Institute of Fluorine Chemical Industry Technology(FCIT20180105)Scientific research Platform Construction Pproject from Fujian Provincial Department of Science and Technology(No.2018H2002).
文摘The influence of various water soluble cations(K^+,Na^+,Ca^2+,Mg^2+)on the hydration of calcined flue gas desulphurization gypsum was investigated.The results show that all cations but Ca^2+can accelerate the hydration of bassanite.The final crystal size is not largely influenced by different salts,except for Na^+,where the giant crystal with length of>130μm is observed.Current study clarifies the influence of different ions on the hydration of bassanite,which could provide sufficient guide for the pre-treatment of original flue gas desulphurization gypsum before actual application.
文摘The application of ionic liquids as alternatives to conventional organic solvents in the extraction process has been investigated. In the present study, fourteen species of imidazolium-based ionic liquids were added into the NaOH （aq） to remove the mercaptans. The influences of anion species and cation alkyl chain length of the imidazolium-based ionic liquids on the performance of mercaptan removal from light oils have been discussed. The efficiency of extraction for mercaptans exhibited the order of [Ac]- 〉 [OH]- [Br]- 〉 [BF4]-. The longer alkyl chain imidazolium-based ionic liquids contributed to enhance desulfurization rate of l-butyl mercaptan. 100% desulfurization rate of l-butyl mercaptan was achieved by the anion of Ac- ionic liquids and NaOH （aq） at a volume ratio of 40：1 （V（oil]：Vfionic liouid）） and a short eouilibrium time within 10 min.
文摘An attempt was made to preserve mango slices by treating with 2% calcium chloride solution followed by dipping into sugar syrup of different concentrations i.e. 50°, 60° and 70 °Brix respectively. The treated slices were subjected for drying in different modes of drying （oven, microwave oven and cabinet tray drying） and analyzed for various physico-chemical and organoleptic quality characteristics. The study revealed that the osmo-air dried slices of mango produced with partial dehydration facilitated by osmotic agent （sugar syrup of 60 °Brix. A fruit： sugar syrup ratio of 1：4 （w/v） for 18 h at 40 ℃ temperature） followed by mechanical drying showed superiority in sensorial quality attributes over other concentrations of ingredients and the rest of the modes of drying. The good quality osmotically dehydrated mango slices could be preserved with maximum retentions of vitamins with better dehydration, rehydration and sensorial quality characteristics.
基金Supported by the National t）asic Research Program of China （2009CB623403）, the National High Technology Research and De velopment Program of China （2009AA034802）, the National Natural Science Foundation of China （20706030, U0834004）, the Science ＆ Technology Support Program （Industry） of Jiangsu Province of China （BE2008141）, the Natural Science Foundation of the Jiangsu Higher Education Institutions （09KJA530002） and 333 High-Level Personnel Training Project in Jiangsu Province. ＊＊ To whom correspondence should be addressed. E-mail： Xuehonggu@yahoo.com
文摘NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value in the feed of isopropanol （IPA） solution on NaA zeolite membranes was investigated. It was found that both factors exhibited strong influence on the stability of NaA zeolite membranes. A set of pretreatment steps such as pH adjustment and distillation of the IPA solution were proposed to improve stability for pervaporation dehydration. An industrial-scale pervaporation facility with 52 m2 membrane area was built to dehydrate IPA solution from industrial cephalosporin production. The facility was continuously operated at 368-378 K to dehydrate IPA solution from water mass content of 15%-20% to less than 2% with a feed flow rate of 400-500 L·h^-1 and an average water flux of 1-1.5 kg·m^-2·h-1. The successful application of this facility suggested a promising application of NaA zeolite mem-brane for IPA recovery from pharmaceutical production.
文摘Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.
文摘The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage ＂blah＂ and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.
基金Supported by the National High Technology Research and Development Program of China（2006AA06Z385） the Science Foundation of Wuhan University of Science and Technology（2008RC06）
文摘Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions：salt concentration 20%-30%,operation tempera-ture 95-100 °C,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.
文摘Response surface methodology, according to CCD （central composite design）, was used to determine the optimum processing conditions giving maximum water loss and minimum solid gain during osmotic dehydration of medlars in sucrose solution. The independent variables of osmotic dehydration were temperature （25-65 ℃）, processing time （20-240 min）, sugar concentration （45%-65% w/w） and blanching time （0-180 s）. The optimum conditions were found to be： temperature = 55 ℃, time = 180 min, concentration = 60° Brix and blanching time = 30 s. At this optimum point, water loss, weight reduction and solid gain were found to be 74.12% and 7.136%, respectively.
基金financially supported by the US National Science Foundation(NSF,MCB-0824837)the Georgia Cancer Coalition(GCC)Distinguished Cancer Clinicians and Scientists Awards
文摘We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of the naturally occurring2′-deoxyguanosine(dG).Unlike the native dG,the UVabsorption ofSedG is significantly influenced by the pH of the aqueous solution.Moreover,SedG is fluorescent at the physiological pH and exhibits pH-dependent fluorescence in aqueous solutions.Furthermore,SedG has noticeable fluorescence in non-aqueous solutions,indicating its sensitivity to environmental changes.This is the first time a fluorescent nucleoside by single-atom alteration has been observed.Fluorescent nucleosides modified by a single atom have great potential as molecular probes with minimal perturbations to investigate nucleoside interactions with proteins,such as membrane-transporter proteins.
