The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumul...The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.展开更多
Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol.This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volu...Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol.This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volume.Herein,the effects of stirring rate,catalyst dosage,reaction temperature,and reaction time on the dehydration reaction of sorbitol were investigated.The yield of isosorbide up to 77.13%was obtained after 1.5 h of reaction time under conditions of 2 kPa,1.0%(mass)catalyst dosage,and 413.15 K.Based on the sorbitol dehydration reaction mechanism and a simplified reaction network,a kinetic model was developed in this work.A good agreement was accomplished between kinetic modeling and experiments between 393.15 and 423.15 K.The fitting results indicate that side reactions with higher activation energies are more affected by reaction temperatures,and the main side reaction that influences the selectivity of isosorbide is the oligomerization reaction among the primary dehydration products of sorbitol.The model fitting of the catalyst amounts effect shows that the effective concentration of sulfuric acid would be reduced with the increase of dosage due to the molecular agglomeration effect.Hopefully,the kinetic experiments and modeling results obtained in this work will be helpful to the design and optimization of the industrial sorbitol dehydration process.展开更多
Drought events have become more severe under climate change,and this can pose a major threat to the survival of various organisms.The molecular mechanisms involved in dehydration resistance are not well known.Here,adu...Drought events have become more severe under climate change,and this can pose a major threat to the survival of various organisms.The molecular mechanisms involved in dehydration resistance are not well known.Here,adults of the migratory locust,Locusta migratoria,were subjected to food-mediated dehydration,and adipokinetic hormone(AKH)signaling was found to play a key role in regulating dehydration resistance.Specifically,dehydration shortened the lifespan,increased the body weight loss,and reduced the water loss rate in adult locusts.Global transcriptome profiles revealed variations in tissue-specific gene expression between dehydration-resistant locusts and normal locusts.Importantly,dehydration selection and exposure induced prominent expression of AKH genes in the retrocerebral complex of adult locusts.Furthermore,individual knockdown of AKH1,AKH2,or AKH receptor(AKHR)accelerated water loss and shortened the lifespan of adult locusts under dehydration conditions,and trehalose supplementation ameliorated the negative effects caused by interference with AKH or AKHR.These findings demonstrated that AKH/AKHR signaling-dependent trehalose metabolism plays a crucial role in regulating locust dehydration resistance and thus provide novel insights into the regulatory mechanism underlying drought resistance.展开更多
It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The ...It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The safety mass concentrations of four raw materials were screened by detecting cell viability,and the secretion of hyaluronic acid(HA)was determined using the ELISA method.The expression of HaCaT barrier function related genes(OVOL1,EREG,TGM1,TGM2,IVL,IRF6,THBS1,CASP14)was detected at the mRNA level to explore the regulatory effect of four raw materials on these genes.The results demonstrate that pretreatment with the four kinds of raw materials could increase the cell viability after hyperosmotic dehydration,promote the secretion of HA,and improve the expression of barrier function related genes after hyperosmotic dehydration,among which panthenol and Calendula officinalis L.are better.The results show that the four raw materials have a certain protective effect on the hyperosmotic dehydration cell model,which provides data support for its application in cosmetics.展开更多
The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate (DMC) via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from...The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate (DMC) via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl2.2H2O and the commercial NH4-form of the Y type zeolite, The catalyst was characterized by X-ray fluorescence (XRF), N2 adsorption (BET method), X-ray diffraction (XRD), and temperature-programmed de- sorption of ammonia (NH3-TPD) to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave (batch reactor) for 18 h at 403 K and 5.5 MPa (2CH3OH + 1/2O2 + CO (CH3O)2CO + H2O). The influence of various dehydrating agents (ZnO, MgO, and CaO) was examined with the aim of increasing the methanol conversion (XMeOH, MeOH conversion). The MeOH conversion increased upon addition of metal oxides in the order CaO 〉〉 MgO 〉 ZnO, with the DMC selectivity (SDMC) following the order MgO 〉 CaO 〉 ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric (TG/DTG), and XRD to con- firm that the dehydration reaction occurred via the metal oxide (MO + H2O →M(OH)2). The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating azent CaO.展开更多
Sb-doped SnO2 (ATO) nanometer powders were synthesized by hydrolysis of alkoxides, using SnCl4·5H2O and SbCl3 as raw materials. Some dehydrating processes, such as n-butanol/xylene mixed solvent heterogeneous a...Sb-doped SnO2 (ATO) nanometer powders were synthesized by hydrolysis of alkoxides, using SnCl4·5H2O and SbCl3 as raw materials. Some dehydrating processes, such as n-butanol/xylene mixed solvent heterogeneous azeotropic distillation, organic dehydrating agent and other dehydrating processes, were used to treat the wet colloids for preparing nonagglomerated ATO nanoparticles. The influences of dehydrating processes on the particle size, agglomeration and resistance were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET). It is indicated that the dehydrating methods have great influences on the products properties, and that n-butanol/xylene mixed solvent heterogeneous azeotropic distillation processing and organic dehydrating agent can effectively remove the residual H2O molecules in wet colloids, and be used to prepare powders with high surface areas, about 85.32 m2/g, low agglomeration and good conductivity.展开更多
The non-isothermal deformation of soft mudrocks or clay soils is one of the most critical issues in energy and environmental related geotechnics.Clay-related geomaterials hold complex microstructure and mineral compos...The non-isothermal deformation of soft mudrocks or clay soils is one of the most critical issues in energy and environmental related geotechnics.Clay-related geomaterials hold complex microstructure and mineral composition,which brings difficulty in investigating their thermo-mechanical behaviors.Previous studies pay little attention to the difference between a thermal plastic strain and the strain from clay dehydration.In this study,a new constitutive model is proposed for describing the thermoelastoplastic behaviors of clayey soils under water-saturated condition.The effect of temperature variation and mechanical loading on elastoplastic strains and dehydration are investigated.The thermodynamics laws and the unconventional plasticity are applied to quantify the thermo-mechanical behavior.The irreversible strain is captured by using Cam-Clay plasticity and subloading yield surface concept.The dehydration strain is described by utilizing a novel method based on generalized thermodynamics approach and Helmholtz free energy function.The internal variables,and the first and second laws of thermodynamics are applied in the model.The hardening rule is established by implementing the laws of physical conservation,energy dissipation,and plastic flow.The proposed model is validated using specially designed thermal consolidation tests on laboratory prepared heavily consolidated clayey soils and some published data of clayey soils with different geological origins.展开更多
Isosorbide is a multi-purpose chemical that can be produced from renewable resources.Specifically,it has been investigated as a replacement for toxic bisphenol A(BPA)in the production of polycarbonate(PC).In this stud...Isosorbide is a multi-purpose chemical that can be produced from renewable resources.Specifically,it has been investigated as a replacement for toxic bisphenol A(BPA)in the production of polycarbonate(PC).In this study,the synthesis of isosorbide by sorbitol dehydration using a cerium-based catalyst derived from calcined cerium(IV)sulfate(300°C,400°C,450°C,500°C,and 650°C)was investigated.The reaction occurred in a high-pressure reactor containing nitrogen gas.Advanced instrumental techniques were applied to analyze the characteristics of the calcined catalyst.The results showed that the calcined catalysts demonstrated different crystalline structures and sulfate species at different temperatures.However,the acidic properties(strength and amount)of the catalyst did not change with the calcination temperature.The cerium(IV)sulfate calcined at 400°C exhibited the best catalytic performance,achieving the highest isosorbide yield(55.7%)and complete conversion of sorbitol at 180°C,20 bar of N2,and 6 h using CeSO-400.The presence of a sulfate group on the catalyst was the most important factor in determining the catalytic performance of sorbitol dehydration to isosorbide.This work suggests that CeSO-400 catalysts may play an important role in reducing reaction conditions.展开更多
The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendlin...The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendliness.The heat storage process of the Ca(OH)_(2)/CaO TCES system in a mixed heating reactor was evaluated in this study,by employing a combination of direct and indirect heating modes.The dehydration process was studied experimentally,and a numerical model was established and verified based on the experimental results.The dehydration behavior of 500 g of Ca(OH)_(2) powder was investigated in a fixed-bed reactor with mixed heating.The experimental and simulation results indicated that mixed heating causes combined centripetal and horizontal propulsion.Heat input is the main limiting factor in the heat storage process,because the radial advance of the reaction is hindered by the low thermal conductivity of the solid reactant particles.Heat transmission partitions were added to enhance the performance of the reactor.The performance of the modified reactor was compared with that of a conventional reactor.The radial heat transmission partitions in the modified reactor effectively enhance the energy storage rate and reduce the reaction time by 59.5%compared with the reactor without partitions.展开更多
基金Supported by the Research and Development Plan of Applied Technology in Heilongjiang Province(GA19B104)。
文摘The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.
文摘Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol.This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volume.Herein,the effects of stirring rate,catalyst dosage,reaction temperature,and reaction time on the dehydration reaction of sorbitol were investigated.The yield of isosorbide up to 77.13%was obtained after 1.5 h of reaction time under conditions of 2 kPa,1.0%(mass)catalyst dosage,and 413.15 K.Based on the sorbitol dehydration reaction mechanism and a simplified reaction network,a kinetic model was developed in this work.A good agreement was accomplished between kinetic modeling and experiments between 393.15 and 423.15 K.The fitting results indicate that side reactions with higher activation energies are more affected by reaction temperatures,and the main side reaction that influences the selectivity of isosorbide is the oligomerization reaction among the primary dehydration products of sorbitol.The model fitting of the catalyst amounts effect shows that the effective concentration of sulfuric acid would be reduced with the increase of dosage due to the molecular agglomeration effect.Hopefully,the kinetic experiments and modeling results obtained in this work will be helpful to the design and optimization of the industrial sorbitol dehydration process.
基金supported by the National Key Research and Development Program of China(2022YFD1400503)the National Natural Science Foundation of China(32102208)the Hebei Natural Science Foundation,China(C2022201042,C2021201052 and C2023201075).
文摘Drought events have become more severe under climate change,and this can pose a major threat to the survival of various organisms.The molecular mechanisms involved in dehydration resistance are not well known.Here,adults of the migratory locust,Locusta migratoria,were subjected to food-mediated dehydration,and adipokinetic hormone(AKH)signaling was found to play a key role in regulating dehydration resistance.Specifically,dehydration shortened the lifespan,increased the body weight loss,and reduced the water loss rate in adult locusts.Global transcriptome profiles revealed variations in tissue-specific gene expression between dehydration-resistant locusts and normal locusts.Importantly,dehydration selection and exposure induced prominent expression of AKH genes in the retrocerebral complex of adult locusts.Furthermore,individual knockdown of AKH1,AKH2,or AKH receptor(AKHR)accelerated water loss and shortened the lifespan of adult locusts under dehydration conditions,and trehalose supplementation ameliorated the negative effects caused by interference with AKH or AKHR.These findings demonstrated that AKH/AKHR signaling-dependent trehalose metabolism plays a crucial role in regulating locust dehydration resistance and thus provide novel insights into the regulatory mechanism underlying drought resistance.
文摘It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The safety mass concentrations of four raw materials were screened by detecting cell viability,and the secretion of hyaluronic acid(HA)was determined using the ELISA method.The expression of HaCaT barrier function related genes(OVOL1,EREG,TGM1,TGM2,IVL,IRF6,THBS1,CASP14)was detected at the mRNA level to explore the regulatory effect of four raw materials on these genes.The results demonstrate that pretreatment with the four kinds of raw materials could increase the cell viability after hyperosmotic dehydration,promote the secretion of HA,and improve the expression of barrier function related genes after hyperosmotic dehydration,among which panthenol and Calendula officinalis L.are better.The results show that the four raw materials have a certain protective effect on the hyperosmotic dehydration cell model,which provides data support for its application in cosmetics.
文摘The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate (DMC) via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl2.2H2O and the commercial NH4-form of the Y type zeolite, The catalyst was characterized by X-ray fluorescence (XRF), N2 adsorption (BET method), X-ray diffraction (XRD), and temperature-programmed de- sorption of ammonia (NH3-TPD) to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave (batch reactor) for 18 h at 403 K and 5.5 MPa (2CH3OH + 1/2O2 + CO (CH3O)2CO + H2O). The influence of various dehydrating agents (ZnO, MgO, and CaO) was examined with the aim of increasing the methanol conversion (XMeOH, MeOH conversion). The MeOH conversion increased upon addition of metal oxides in the order CaO 〉〉 MgO 〉 ZnO, with the DMC selectivity (SDMC) following the order MgO 〉 CaO 〉 ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric (TG/DTG), and XRD to con- firm that the dehydration reaction occurred via the metal oxide (MO + H2O →M(OH)2). The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating azent CaO.
文摘Sb-doped SnO2 (ATO) nanometer powders were synthesized by hydrolysis of alkoxides, using SnCl4·5H2O and SbCl3 as raw materials. Some dehydrating processes, such as n-butanol/xylene mixed solvent heterogeneous azeotropic distillation, organic dehydrating agent and other dehydrating processes, were used to treat the wet colloids for preparing nonagglomerated ATO nanoparticles. The influences of dehydrating processes on the particle size, agglomeration and resistance were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET). It is indicated that the dehydrating methods have great influences on the products properties, and that n-butanol/xylene mixed solvent heterogeneous azeotropic distillation processing and organic dehydrating agent can effectively remove the residual H2O molecules in wet colloids, and be used to prepare powders with high surface areas, about 85.32 m2/g, low agglomeration and good conductivity.
基金funded by Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant Canada(Grant No.RGPIN-2017-05169).
文摘The non-isothermal deformation of soft mudrocks or clay soils is one of the most critical issues in energy and environmental related geotechnics.Clay-related geomaterials hold complex microstructure and mineral composition,which brings difficulty in investigating their thermo-mechanical behaviors.Previous studies pay little attention to the difference between a thermal plastic strain and the strain from clay dehydration.In this study,a new constitutive model is proposed for describing the thermoelastoplastic behaviors of clayey soils under water-saturated condition.The effect of temperature variation and mechanical loading on elastoplastic strains and dehydration are investigated.The thermodynamics laws and the unconventional plasticity are applied to quantify the thermo-mechanical behavior.The irreversible strain is captured by using Cam-Clay plasticity and subloading yield surface concept.The dehydration strain is described by utilizing a novel method based on generalized thermodynamics approach and Helmholtz free energy function.The internal variables,and the first and second laws of thermodynamics are applied in the model.The hardening rule is established by implementing the laws of physical conservation,energy dissipation,and plastic flow.The proposed model is validated using specially designed thermal consolidation tests on laboratory prepared heavily consolidated clayey soils and some published data of clayey soils with different geological origins.
基金The authors appreciative and acknowledge the Faculty of Engineering,Khon Kaen University,Thailand,and the Graduate School,Khon Kaen University,Thailand,for supporting the Lecturer in Admitting High Potential Students to Study and Research in His Expert Program Year 2018(Grant No.611JT212)。
文摘Isosorbide is a multi-purpose chemical that can be produced from renewable resources.Specifically,it has been investigated as a replacement for toxic bisphenol A(BPA)in the production of polycarbonate(PC).In this study,the synthesis of isosorbide by sorbitol dehydration using a cerium-based catalyst derived from calcined cerium(IV)sulfate(300°C,400°C,450°C,500°C,and 650°C)was investigated.The reaction occurred in a high-pressure reactor containing nitrogen gas.Advanced instrumental techniques were applied to analyze the characteristics of the calcined catalyst.The results showed that the calcined catalysts demonstrated different crystalline structures and sulfate species at different temperatures.However,the acidic properties(strength and amount)of the catalyst did not change with the calcination temperature.The cerium(IV)sulfate calcined at 400°C exhibited the best catalytic performance,achieving the highest isosorbide yield(55.7%)and complete conversion of sorbitol at 180°C,20 bar of N2,and 6 h using CeSO-400.The presence of a sulfate group on the catalyst was the most important factor in determining the catalytic performance of sorbitol dehydration to isosorbide.This work suggests that CeSO-400 catalysts may play an important role in reducing reaction conditions.
文摘The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendliness.The heat storage process of the Ca(OH)_(2)/CaO TCES system in a mixed heating reactor was evaluated in this study,by employing a combination of direct and indirect heating modes.The dehydration process was studied experimentally,and a numerical model was established and verified based on the experimental results.The dehydration behavior of 500 g of Ca(OH)_(2) powder was investigated in a fixed-bed reactor with mixed heating.The experimental and simulation results indicated that mixed heating causes combined centripetal and horizontal propulsion.Heat input is the main limiting factor in the heat storage process,because the radial advance of the reaction is hindered by the low thermal conductivity of the solid reactant particles.Heat transmission partitions were added to enhance the performance of the reactor.The performance of the modified reactor was compared with that of a conventional reactor.The radial heat transmission partitions in the modified reactor effectively enhance the energy storage rate and reduce the reaction time by 59.5%compared with the reactor without partitions.