There is a pressing demand for the development of novel birefringent crystals tailored for compact optical components,especially for crystals exhibiting large birefringence across a range of temperatures.This has comm...There is a pressing demand for the development of novel birefringent crystals tailored for compact optical components,especially for crystals exhibiting large birefringence across a range of temperatures.This has commonly been achieved by introducing various deformable groups with high polarizability anisotropy.In this study,we combined both rigid and deformable groups to synthesise a new birefringent crystal,Al_(2)Te_(2)MoO_(10),which demonstrates an exceptional birefringence value of 0.29@550 nm at room temperature.Not only is this higher birefringence than that of commercial crystals,but Al_(2)Te_(2)MoO_(10)exhibits excellent birefringence stability over a wide temperature range,from 123 to 503 K.In addition,the first-principles theory calculations and structural analyses suggest that although the rigid AlO_(6)groups do not make much contribution to the prominent birefringence,they nonetheless played a role in maintaining the structural anisotropy at elevated temperatures.Based on these findings,this paper proposes a novel structural design strategy to complement conventional approaches for developing optimal birefringent crystals under various environmental conditions.展开更多
Efficiently using petroleum coke as fuel and reducing carbon emission meanwhile have become attractive in oil processing industry.The paper is focused on the application of Chemical Looping Combustion(CLC)with petrole...Efficiently using petroleum coke as fuel and reducing carbon emission meanwhile have become attractive in oil processing industry.The paper is focused on the application of Chemical Looping Combustion(CLC)with petroleum coke,with the purpose of investigating its combustion performance and effects of potassium.Some experiments were performed in a laboratory scale fluidized bed facility with a natural manganese-based oxygen carrier.Experimental results indicated that the coke conversion is very sensitive to reaction temperature.The pre sent natural manganese-based oxygen carrier decorated by K has little effect on the improvement of coke conversion.XRD,SEM-EDX,and H2-TPR were adopted to characterize the reacted oxygen carrier samples.After being decorated by K,the oxygen carrier's capacity of transferring oxygen was decrea sed.A calcination temperature above the melting point of K2 CO3(891℃)shows better oxygen transfer reactivity in comparison to the one calcined at a lower temperature.The natural oxygen carrier used in the work has a high content of Si,which can easily react with K to form K(FeSi2 O6).Further,irrespective of reaction temperature,the coke conversion can be significantly enhanced by decorating the coke with K,with a demonstration of remarkably shorter reaction time,faster average coke gasification rate and higher average carbon conversion rate.展开更多
A series of newπ-conjugated macrocycles(AzoM-n-E,n 1–3)incorporating=azobenzene units have been synthesized by a facile strategy in one-pot reaction.The resultant azobenzene-embedded macrocycles feature intrinsic ph...A series of newπ-conjugated macrocycles(AzoM-n-E,n 1–3)incorporating=azobenzene units have been synthesized by a facile strategy in one-pot reaction.The resultant azobenzene-embedded macrocycles feature intrinsic photoresponsive behaviors and intriguing supramolecular assembling properties.The smallest macro-cycle AzoM-1-E with a rigid planar conjugated backbone structure is used to prepare the single crystal transistors,showing reversible optical tunability.The moderate size macrocycle AzoM-2-E assembles into a dimer in the form of interpenetration throughπ-πstacking between azobenzene units.The largest macrocycle AzoM-3-E with enhancedflexibility can adaptively assemble with various types of electron-deficient guests accompanied by distortion of azobenzene.Typically,AzoM-3-E assembles with the planar F4-TCNQ to form a tetragonal geometry by C-F⋅⋅⋅π and π-π interactions,while the assembly with ellipsoidal C70 viaπ-πinteractions induces AzoM-3-E to form a boat-shaped geometry.This work will shed new light on the development of functional conjugated macrocycles in organic electronics.展开更多
基金supported by the National Natural Science Foundation of China(22122507,61975207,22193042,21833010,and 21921001)the Natural Science Foundation of Fujian Province(2022J02012)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202069)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LYSLH024)the China Postdoctoral Science Foundation(2023M743498)。
文摘There is a pressing demand for the development of novel birefringent crystals tailored for compact optical components,especially for crystals exhibiting large birefringence across a range of temperatures.This has commonly been achieved by introducing various deformable groups with high polarizability anisotropy.In this study,we combined both rigid and deformable groups to synthesise a new birefringent crystal,Al_(2)Te_(2)MoO_(10),which demonstrates an exceptional birefringence value of 0.29@550 nm at room temperature.Not only is this higher birefringence than that of commercial crystals,but Al_(2)Te_(2)MoO_(10)exhibits excellent birefringence stability over a wide temperature range,from 123 to 503 K.In addition,the first-principles theory calculations and structural analyses suggest that although the rigid AlO_(6)groups do not make much contribution to the prominent birefringence,they nonetheless played a role in maintaining the structural anisotropy at elevated temperatures.Based on these findings,this paper proposes a novel structural design strategy to complement conventional approaches for developing optimal birefringent crystals under various environmental conditions.
基金supported by the National Natural Foundation of China(51906113)Natural Science Foundation of Jiangsu province(BK20190707)+1 种基金Key Research and Development(R&D)Projects of Shanxi Province(201903D121031)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2020-KF-05)。
文摘Efficiently using petroleum coke as fuel and reducing carbon emission meanwhile have become attractive in oil processing industry.The paper is focused on the application of Chemical Looping Combustion(CLC)with petroleum coke,with the purpose of investigating its combustion performance and effects of potassium.Some experiments were performed in a laboratory scale fluidized bed facility with a natural manganese-based oxygen carrier.Experimental results indicated that the coke conversion is very sensitive to reaction temperature.The pre sent natural manganese-based oxygen carrier decorated by K has little effect on the improvement of coke conversion.XRD,SEM-EDX,and H2-TPR were adopted to characterize the reacted oxygen carrier samples.After being decorated by K,the oxygen carrier's capacity of transferring oxygen was decrea sed.A calcination temperature above the melting point of K2 CO3(891℃)shows better oxygen transfer reactivity in comparison to the one calcined at a lower temperature.The natural oxygen carrier used in the work has a high content of Si,which can easily react with K to form K(FeSi2 O6).Further,irrespective of reaction temperature,the coke conversion can be significantly enhanced by decorating the coke with K,with a demonstration of remarkably shorter reaction time,faster average coke gasification rate and higher average carbon conversion rate.
基金National Key R&D Program of China,Grant/Award Number:2018YFA0703200National Natural Science Foundation of China,Grant/Award Numbers:61890940,52073063+1 种基金Program for Professor of Special Appointment(Eastern Scholar)at the Shanghai Institutions of Higher LearningNatural Science Foundation of Shanghai,Grant/Award Numbers:22ZR1405800,23ZR1405100。
文摘A series of newπ-conjugated macrocycles(AzoM-n-E,n 1–3)incorporating=azobenzene units have been synthesized by a facile strategy in one-pot reaction.The resultant azobenzene-embedded macrocycles feature intrinsic photoresponsive behaviors and intriguing supramolecular assembling properties.The smallest macro-cycle AzoM-1-E with a rigid planar conjugated backbone structure is used to prepare the single crystal transistors,showing reversible optical tunability.The moderate size macrocycle AzoM-2-E assembles into a dimer in the form of interpenetration throughπ-πstacking between azobenzene units.The largest macrocycle AzoM-3-E with enhancedflexibility can adaptively assemble with various types of electron-deficient guests accompanied by distortion of azobenzene.Typically,AzoM-3-E assembles with the planar F4-TCNQ to form a tetragonal geometry by C-F⋅⋅⋅π and π-π interactions,while the assembly with ellipsoidal C70 viaπ-πinteractions induces AzoM-3-E to form a boat-shaped geometry.This work will shed new light on the development of functional conjugated macrocycles in organic electronics.
