The deep-processing utility of pure hydrogen sulfide (H_(2)S) is a significant direction in natural gas chemical industry.Herein,a brand-new strategy of H_(2)S conversion by a,β-unsaturated carboxylate esters into th...The deep-processing utility of pure hydrogen sulfide (H_(2)S) is a significant direction in natural gas chemical industry.Herein,a brand-new strategy of H_(2)S conversion by a,β-unsaturated carboxylate esters into thiols or thioethers using task-specific carboxylate ionic liquids (ILs) as catalyst has been developed,firstly accomplishing the phase separation of product and catalyst without introducing the third component.It can be considered as a cascade reaction in which the product selectivity can be controlled by adjusting the molar ratio of H_(2)S to a,β-unsaturated carboxylate esters.Also,the effects of ILs with different anions and cations,intermittent feeding operations,as well as pressure-time kinetic behaviors on cascade reaction were investigated.Furthermore,the proposed interaction mechanism of H_(2)S conversion using butyl acrylate catalyzed by[Emim][Ac]was revealed by DFT-based theoretical calculation.The approach enables the self-phase separation promotion of catalyst and product and achieves 99%quantitative conversion under mild conditions in the absence of solvent,making the entire process ecologically benign.High-efficiency reaction activity can still be maintained after ten cycles of the catalyst.Therefore,the good results,combined with its simplicity of operation and the high recyclability of the catalyst,make this green method environmentally friendly and cost-effective.It is anticipated that this self-separation method mediated by task-specific ILs will provide a feasible strategy for H_(2)S utilization,which will guide its application on an industrial scale.展开更多
The utilization of black soldier fly larvae(BSFL)in food waste treatment has garnered significant attention because of its alignment with the principles of a circular economy.However,in rural areas,inadequate manageme...The utilization of black soldier fly larvae(BSFL)in food waste treatment has garnered significant attention because of its alignment with the principles of a circular economy.However,in rural areas,inadequate management of waste segregation and a high proportion of difficult-to-decompose materials in food waste have reduced the treatment rate by BSFL.After a year-long investigation into rural food waste,we designed a BSFL continuous self-separation reactor,which incorporated microorganisms to enhance waste degradation.The reactor also maintained heat retention,facilitated leachate collection,and enabled the continuous feeding and automated separation of adult black soldier flies.Both single-batch and multi-batch continuous operation modes of the reactor consistently and effectively treated food waste.In the single-batch mode,operation for 10 d resulted in a 38.9%reduction in the wet weight of food waste,with a larval biomass yield of 80.9 g/kg.In the multi-batch continuous mode,operation for 32 d led to a 56.6%reduction in the wet weight of food waste,with a larval biomass yield of 64.7 g/kg.In addition,a 24-h sufficient consumption experiment revealed that the degradation of organic matter in rural food waste was significantly affected by the combined efforts of BSFL and microorganisms.The harvested larvae exhibited high levels of crude protein and crude fat,making them a valuable high-protein,high-fat animal feed.Overall,the reactor demonstrated notable space efficiency and effective waste reduction,providing key insights into the use of BSFL for food waste management.展开更多
The selective oxidation of para-xylene(PX)to terephthalic acid(TPA)has received increasing attention due to the industrial applications of TPA.However,the oxidation of the C(sp^(3))‒H bond of PX is still a main challe...The selective oxidation of para-xylene(PX)to terephthalic acid(TPA)has received increasing attention due to the industrial applications of TPA.However,the oxidation of the C(sp^(3))‒H bond of PX is still a main challenge because of the higher bond dissociation energy.Herein,an efficient photocatalytic system for the oxidation of PX to TPA was developed by using tetrabutylammonium decatungstate(TBADT)photocatalyst using atmospheric oxygen as oxidant and 365 nm LED light irradiation.The resulting TPA product was easily separated from the post-reaction solution through simple filtration treatment with a 93.4%yield in CH3CN(37.5%1 mol L^(‒1) HCl)solvent after 19-h photocatalysis.Given the easy separation of TPA and the excellent recycling stability of TBADT,a continuous-flow photoreactor was successfully designed with promising prospect for potential industrial application.Mechanistic studies elucidated that the presence of HCl additive benefits the structural integrity of[W10O32]4−anions and the transition from excited states[W_(10)O_(32)]^(4‒*)to wO active species,leading to enhanced photooxidation performance.展开更多
Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the ...Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete-continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational envi- ronment. A second-order system is established by combining the point mass model and the propor- tional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally set- ting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.展开更多
In this work,a series of novel proton-gradient-transfer acid complexes(PGTACs)were developed.Their physicochemical properties,including thermal stability,melting point,and Hammett acidity,were measured.The effects of ...In this work,a series of novel proton-gradient-transfer acid complexes(PGTACs)were developed.Their physicochemical properties,including thermal stability,melting point,and Hammett acidity,were measured.The effects of catalyst loading,reaction temperature,and substrate expansion on the catalytic performance were systematically studied.It is found that the combination of bidentate N-heterocycle and H;SO;(1:2 M ratio)could form simultaneously N–H covalent bond and N…H hydrogen bond,which makes the PGTACs excellent catalysts integrate the advantages of strong acids(high catalytic activity)and ionic liquids(phase separation)in the esterification reaction.Moreover,these PGTACs can be reused by convenient phase separation without obvious diminution of catalytic activity.It is concluded that these PGTACs are potential alternative candidates for esterification reaction in the process of industrial catalysis.展开更多
Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the prot...Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterifica- tion of terpenols. These PGTACs are ＂reaction-induced self-separation catalysts＂ and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.展开更多
In this work,a method to acquire freestanding GaN by using low temperature(LT)-GaN layer was put forward.To obtain porous structure and increase the crystallinity,LT-GaN layers were annealed at high temperature.The mo...In this work,a method to acquire freestanding GaN by using low temperature(LT)-GaN layer was put forward.To obtain porous structure and increase the crystallinity,LT-GaN layers were annealed at high temperature.The morphology of LTGaN layers with different thickness and annealing temperature before and after annealing was analyzed.Comparison of GaN films using different LT-GaN layers was made to acquire optimal LT-GaN process.According to HRXRD and Raman results,GaN grown on 800 nm LT-GaN layer which was annealed at 1090℃ has good crystal quality and small stress.The GaN film was successfully separated from the substrate after cooling down.The self-separation mechanism of this method was discussed.Cross-sectional EBSD mapping measurements were carried out to investigate the effect of LT-buffer layer on improvement of crystal quality and stress relief.The optical property of the obtained freestanding GaN film was also determined by PL measurement.展开更多
基金sponsored by the National Natural Science Foundation of China (Nos. 22208140 and 22078145)。
文摘The deep-processing utility of pure hydrogen sulfide (H_(2)S) is a significant direction in natural gas chemical industry.Herein,a brand-new strategy of H_(2)S conversion by a,β-unsaturated carboxylate esters into thiols or thioethers using task-specific carboxylate ionic liquids (ILs) as catalyst has been developed,firstly accomplishing the phase separation of product and catalyst without introducing the third component.It can be considered as a cascade reaction in which the product selectivity can be controlled by adjusting the molar ratio of H_(2)S to a,β-unsaturated carboxylate esters.Also,the effects of ILs with different anions and cations,intermittent feeding operations,as well as pressure-time kinetic behaviors on cascade reaction were investigated.Furthermore,the proposed interaction mechanism of H_(2)S conversion using butyl acrylate catalyzed by[Emim][Ac]was revealed by DFT-based theoretical calculation.The approach enables the self-phase separation promotion of catalyst and product and achieves 99%quantitative conversion under mild conditions in the absence of solvent,making the entire process ecologically benign.High-efficiency reaction activity can still be maintained after ten cycles of the catalyst.Therefore,the good results,combined with its simplicity of operation and the high recyclability of the catalyst,make this green method environmentally friendly and cost-effective.It is anticipated that this self-separation method mediated by task-specific ILs will provide a feasible strategy for H_(2)S utilization,which will guide its application on an industrial scale.
基金supported by the National Key Research and Development Project(No.2018YFD1100601-03).
文摘The utilization of black soldier fly larvae(BSFL)in food waste treatment has garnered significant attention because of its alignment with the principles of a circular economy.However,in rural areas,inadequate management of waste segregation and a high proportion of difficult-to-decompose materials in food waste have reduced the treatment rate by BSFL.After a year-long investigation into rural food waste,we designed a BSFL continuous self-separation reactor,which incorporated microorganisms to enhance waste degradation.The reactor also maintained heat retention,facilitated leachate collection,and enabled the continuous feeding and automated separation of adult black soldier flies.Both single-batch and multi-batch continuous operation modes of the reactor consistently and effectively treated food waste.In the single-batch mode,operation for 10 d resulted in a 38.9%reduction in the wet weight of food waste,with a larval biomass yield of 80.9 g/kg.In the multi-batch continuous mode,operation for 32 d led to a 56.6%reduction in the wet weight of food waste,with a larval biomass yield of 64.7 g/kg.In addition,a 24-h sufficient consumption experiment revealed that the degradation of organic matter in rural food waste was significantly affected by the combined efforts of BSFL and microorganisms.The harvested larvae exhibited high levels of crude protein and crude fat,making them a valuable high-protein,high-fat animal feed.Overall,the reactor demonstrated notable space efficiency and effective waste reduction,providing key insights into the use of BSFL for food waste management.
文摘The selective oxidation of para-xylene(PX)to terephthalic acid(TPA)has received increasing attention due to the industrial applications of TPA.However,the oxidation of the C(sp^(3))‒H bond of PX is still a main challenge because of the higher bond dissociation energy.Herein,an efficient photocatalytic system for the oxidation of PX to TPA was developed by using tetrabutylammonium decatungstate(TBADT)photocatalyst using atmospheric oxygen as oxidant and 365 nm LED light irradiation.The resulting TPA product was easily separated from the post-reaction solution through simple filtration treatment with a 93.4%yield in CH3CN(37.5%1 mol L^(‒1) HCl)solvent after 19-h photocatalysis.Given the easy separation of TPA and the excellent recycling stability of TBADT,a continuous-flow photoreactor was successfully designed with promising prospect for potential industrial application.Mechanistic studies elucidated that the presence of HCl additive benefits the structural integrity of[W10O32]4−anions and the transition from excited states[W_(10)O_(32)]^(4‒*)to wO active species,leading to enhanced photooxidation performance.
基金supported by the National Natural Science Foundation of China (No.61104159)National Science and Technology Support Project (2011BAH24B08)the National Hightech Research and Development Program of China(No.2011BAH24B08)
文摘Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete-continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational envi- ronment. A second-order system is established by combining the point mass model and the propor- tional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally set- ting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.
基金sponsored by the National Natural Science Foundation of China(Nos.21576129 and 21878141)the Natural Science Foundation of Jiangsu Province(BK20190310)for financial supports
文摘In this work,a series of novel proton-gradient-transfer acid complexes(PGTACs)were developed.Their physicochemical properties,including thermal stability,melting point,and Hammett acidity,were measured.The effects of catalyst loading,reaction temperature,and substrate expansion on the catalytic performance were systematically studied.It is found that the combination of bidentate N-heterocycle and H;SO;(1:2 M ratio)could form simultaneously N–H covalent bond and N…H hydrogen bond,which makes the PGTACs excellent catalysts integrate the advantages of strong acids(high catalytic activity)and ionic liquids(phase separation)in the esterification reaction.Moreover,these PGTACs can be reused by convenient phase separation without obvious diminution of catalytic activity.It is concluded that these PGTACs are potential alternative candidates for esterification reaction in the process of industrial catalysis.
基金supported by the National Natural Science Foundation of China (21376115, 21576129)~~
文摘Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterifica- tion of terpenols. These PGTACs are ＂reaction-induced self-separation catalysts＂ and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51702226,51572153 and 51602177)the Natural Science Foundation of Shanxi Province(Grant No.201701D221078).
文摘In this work,a method to acquire freestanding GaN by using low temperature(LT)-GaN layer was put forward.To obtain porous structure and increase the crystallinity,LT-GaN layers were annealed at high temperature.The morphology of LTGaN layers with different thickness and annealing temperature before and after annealing was analyzed.Comparison of GaN films using different LT-GaN layers was made to acquire optimal LT-GaN process.According to HRXRD and Raman results,GaN grown on 800 nm LT-GaN layer which was annealed at 1090℃ has good crystal quality and small stress.The GaN film was successfully separated from the substrate after cooling down.The self-separation mechanism of this method was discussed.Cross-sectional EBSD mapping measurements were carried out to investigate the effect of LT-buffer layer on improvement of crystal quality and stress relief.The optical property of the obtained freestanding GaN film was also determined by PL measurement.
