Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials,phenolic hydroxyl groups were introduced in lignosulfonate(LS)via the alkyl chain bridging method to p...Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials,phenolic hydroxyl groups were introduced in lignosulfonate(LS)via the alkyl chain bridging method to prepare phenolated-lignosulfonate(PLS).The results showed that the phenolic group was boosted from 0.81 mmol∙g^(–1) of LS to 1.19 mmol∙g^(–1) of PLS.The electrochemical property results showed two oxidation peaks in the cyclic voltammogram(CV)curve of PLS,and the oxidation potential of the PLS-modified electrode decreased by 0.5 eV compared with that of LS.This result indicates that PLS is more easily oxidized than LS.Based on the excellent electron transporting property of PLS,PLS was applied as a dopant in poly(3,4-ethylenedioxythiophene)(PEDOT,called PEDOT:PLSs).PLS showed excellent dispersion properties for PEDOT.Moreover,the transmittance measurement results showed that the transmittance of PEDOT:PLSs exceeded 85%in the range of 300–800 nm.The CV results showed that the energy levels of PEDOT:PLSs could be flexibly adjusted by PLS amounts.The results indicate that the phenolic hydroxyl group of lignin can be easily boosted by the alkyl chain bridging method,and phenolated lignin-based polymers may have promising potential as dopants of PEDOT to produce hole transporting materials for different organic photovoltaic devices.展开更多
The group-hole nozzle concept is proposed to meet the requirement of nozzle hole minimization and reduce the negative impact of poor spatial spray distributions.However,there are limited researches on the effects of i...The group-hole nozzle concept is proposed to meet the requirement of nozzle hole minimization and reduce the negative impact of poor spatial spray distributions.However,there are limited researches on the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle.Therefore,in this study,an accurate spray model coupled with the internal cavitating flow was established and computational fluid dynamics(CFD)simulations were done to study the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle.Experimental data obtained using high-speed digital camera on the high-pressure common rail injection system was used to validate the numerical model.Effects of intake conditions(injection pressure and temperature)and nozzle geometry(orifice entrance curvature radius and nozzle length)on the flow and spray characteristics of the group-hole nozzle were studied numerically.The differences in Sauter mean diameter(SMD),penetration length and fuel evaporation mass between single-hole nozzle and group-hole nozzle under different nozzle geometry were also discussed.It was found that the atomization performance of the group-hole nozzle was better than that of the single-hole nozzle under same intake conditions,and the atomization effect of the short nozzle was better than that of the long nozzle.With increase in the orifice entrance curvature radius,the average velocity and turbulent kinetic energy of the fuel increased,which was conducive to improving the injection rate and flow coefficient of the nozzle.Meanwhile,the penetration length and SMD value rose,while evaporation mass dropped.When the ratio of the orifice entrance curvature radius(R)to the diameter of injection hole(D)was 0.12,the spray characteristics reached a constant state due to elimination of cavitation.Conclusions were made based on these.This study is expected to be a guide for the design of the group-hole nozzle.展开更多
Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butyl...Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine])have been widely adopted as hole-transport materials due to their perovskite passivation effects and suitable energy levels.However,the passivation mechanism(i.e.,the functional group responsible for perovskite passivation)of triphenylamine derivative polymers remains unclear,hindering the development and application of this polymer type.Here,we develop a novel Poly-TPD derivative,S-Poly-TPD,by replacing the n-butyl functional group of Poly-TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top-deposited perovskite properties.Compared with Poly-TPD,the increased CH_(3)-terminal unit density and the decreased spatial distance between the-CH-CH_(3) and-CH_(2)-CH_(3) units and the benzene ring in S-Poly-TPD not only enhanced the hole-transport ability but also improved the perovskite passivation effect,revealing for the first time the role of the alkyl groups in perovskite passivation.As a result,the S-Poly-TPD-based IPVSCs demonstrated high power-conversion efficiencies of 15.1% and 21.3% in wide-bandgap[MAPbI_(2)Br(SCN)0.12]and normal-bandgap[(FAPbI_(3))0.92(MAPbBr_(3))0.08]devices,respectively.展开更多
借助高速摄影观察发现,水稻气力式精量穴播排种器吸种盘上吸孔所吸附的种子会由于吸力不足,在离心力作用下,在到达投种区前从吸孔附近落下,从而产生＂飞种＂现象,进而对排种器排出的每穴种子数量以及成穴性产生影响,降低排种精度。为此...借助高速摄影观察发现,水稻气力式精量穴播排种器吸种盘上吸孔所吸附的种子会由于吸力不足,在离心力作用下,在到达投种区前从吸孔附近落下,从而产生＂飞种＂现象,进而对排种器排出的每穴种子数量以及成穴性产生影响,降低排种精度。为此,设计了一种挡种装置,以含水率为21.1%的培杂泰丰种子为对象,采用多因素试验的方法,研究了不同吸室负压和不同排种盘转速下,安装挡种装置前后对＂飞种＂现象的影响;采用单因素试验的方法,研究了安装挡种装置后不同吸室负压下,不同排种盘转速对排种器吸种精度的影响。结果表明,安装挡种装置后,＂飞种＂出现范围减小,＂飞种＂出现的数量减少,排种器排种精度与成穴性能提高;当转速在25～40 r/min,吸室负压1.6 k Pa时,（1-3）粒/穴概率在93%～97%之间变化。试验结果显示安装挡种装置后能控制＂飞种＂的跌落范围,并使部分＂飞种＂落回充种室内,从而提高排种器排种精度。展开更多
The complex method of the plane elasticity in 2D quasicrystal with point group 10 mm tenfold rotational symmetry is established. First displacement potential function in the quasicrystal is represented by four analyti...The complex method of the plane elasticity in 2D quasicrystal with point group 10 mm tenfold rotational symmetry is established. First displacement potential function in the quasicrystal is represented by four analytic functions. Then by utilizing the properties of analytic function and through a great deal of derivation, the complex representations of stresses and displacementscomponents of phonon fields and phason fields in the quasicrystal are given, which are the theo-retical foundation for this method. From this theory, and by the help of conformal transformations in the theory of complex function, the problems of elliptic hole in the quasicrystal are solved. Its spe-cial cases are the solutions of well-known crack problem. Meanwhile, the results show that even if under the self-counterbalance force in the quasicrystal plane with elliptic hole, the stress compo-nents of phonon fields are also related to material constants of the quasicrystal when the phonon fields and phason fields are coupled, which is another distinctive difference from the properties of classical elastic theory. Besides, the present work is generalization and application of the complex method in the classical elastic theory established by Muskhelishvili to 2D quasicrystal. As in the classical elastic theory, if only conformal transformation from the quasicrystal plane to unit circle isfound, any holey and crack problem in the quasicrystal plane could be solved.展开更多
基金The authors would like to acknowledge the financial support of Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515111167)Doctoral Research Initiation Foundation of Dongguan University of Technology(GC300501-075)+1 种基金Rural Science and Technology Commissioner Project of Guangdong Provincial Science and Technology Department(Grant No.KTP20200245)Innovation and Entrepreneurship Projects for College Students(Grant Nos.202211819092 and 202211819225).
文摘Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials,phenolic hydroxyl groups were introduced in lignosulfonate(LS)via the alkyl chain bridging method to prepare phenolated-lignosulfonate(PLS).The results showed that the phenolic group was boosted from 0.81 mmol∙g^(–1) of LS to 1.19 mmol∙g^(–1) of PLS.The electrochemical property results showed two oxidation peaks in the cyclic voltammogram(CV)curve of PLS,and the oxidation potential of the PLS-modified electrode decreased by 0.5 eV compared with that of LS.This result indicates that PLS is more easily oxidized than LS.Based on the excellent electron transporting property of PLS,PLS was applied as a dopant in poly(3,4-ethylenedioxythiophene)(PEDOT,called PEDOT:PLSs).PLS showed excellent dispersion properties for PEDOT.Moreover,the transmittance measurement results showed that the transmittance of PEDOT:PLSs exceeded 85%in the range of 300–800 nm.The CV results showed that the energy levels of PEDOT:PLSs could be flexibly adjusted by PLS amounts.The results indicate that the phenolic hydroxyl group of lignin can be easily boosted by the alkyl chain bridging method,and phenolated lignin-based polymers may have promising potential as dopants of PEDOT to produce hole transporting materials for different organic photovoltaic devices.
基金supported by the National Natural Science Foundation of China(Grant No.52276117)and Qing Lan Project。
文摘The group-hole nozzle concept is proposed to meet the requirement of nozzle hole minimization and reduce the negative impact of poor spatial spray distributions.However,there are limited researches on the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle.Therefore,in this study,an accurate spray model coupled with the internal cavitating flow was established and computational fluid dynamics(CFD)simulations were done to study the effects of intake conditions and nozzle geometry on spray characteristics of the group-hole nozzle.Experimental data obtained using high-speed digital camera on the high-pressure common rail injection system was used to validate the numerical model.Effects of intake conditions(injection pressure and temperature)and nozzle geometry(orifice entrance curvature radius and nozzle length)on the flow and spray characteristics of the group-hole nozzle were studied numerically.The differences in Sauter mean diameter(SMD),penetration length and fuel evaporation mass between single-hole nozzle and group-hole nozzle under different nozzle geometry were also discussed.It was found that the atomization performance of the group-hole nozzle was better than that of the single-hole nozzle under same intake conditions,and the atomization effect of the short nozzle was better than that of the long nozzle.With increase in the orifice entrance curvature radius,the average velocity and turbulent kinetic energy of the fuel increased,which was conducive to improving the injection rate and flow coefficient of the nozzle.Meanwhile,the penetration length and SMD value rose,while evaporation mass dropped.When the ratio of the orifice entrance curvature radius(R)to the diameter of injection hole(D)was 0.12,the spray characteristics reached a constant state due to elimination of cavitation.Conclusions were made based on these.This study is expected to be a guide for the design of the group-hole nozzle.
基金The work was financially supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302007)the Ministry of Science and Technology(Nos.2017YFA0206600,2019YFA 0705900)+3 种基金the Natural Science Foundation of China(Nos.51973063,91733302 and 51803060)the Science and Technology Program of Guangdong Province,China(No.2018A030313045)the Science and Technology Program of Guangzhou,China(No.201904010147).Yue‐Min Xie acknowledged the funding by State Key Lab of Luminescent Materials and Devices,South China Uni-versity of Technology,the Fellowship of China Post-doctoral Science Foundation(No.2020M682703)the National Natural Science Foundation of China(No.52003090).
文摘Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine])have been widely adopted as hole-transport materials due to their perovskite passivation effects and suitable energy levels.However,the passivation mechanism(i.e.,the functional group responsible for perovskite passivation)of triphenylamine derivative polymers remains unclear,hindering the development and application of this polymer type.Here,we develop a novel Poly-TPD derivative,S-Poly-TPD,by replacing the n-butyl functional group of Poly-TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top-deposited perovskite properties.Compared with Poly-TPD,the increased CH_(3)-terminal unit density and the decreased spatial distance between the-CH-CH_(3) and-CH_(2)-CH_(3) units and the benzene ring in S-Poly-TPD not only enhanced the hole-transport ability but also improved the perovskite passivation effect,revealing for the first time the role of the alkyl groups in perovskite passivation.As a result,the S-Poly-TPD-based IPVSCs demonstrated high power-conversion efficiencies of 15.1% and 21.3% in wide-bandgap[MAPbI_(2)Br(SCN)0.12]and normal-bandgap[(FAPbI_(3))0.92(MAPbBr_(3))0.08]devices,respectively.
文摘借助高速摄影观察发现,水稻气力式精量穴播排种器吸种盘上吸孔所吸附的种子会由于吸力不足,在离心力作用下,在到达投种区前从吸孔附近落下,从而产生＂飞种＂现象,进而对排种器排出的每穴种子数量以及成穴性产生影响,降低排种精度。为此,设计了一种挡种装置,以含水率为21.1%的培杂泰丰种子为对象,采用多因素试验的方法,研究了不同吸室负压和不同排种盘转速下,安装挡种装置前后对＂飞种＂现象的影响;采用单因素试验的方法,研究了安装挡种装置后不同吸室负压下,不同排种盘转速对排种器吸种精度的影响。结果表明,安装挡种装置后,＂飞种＂出现范围减小,＂飞种＂出现的数量减少,排种器排种精度与成穴性能提高;当转速在25～40 r/min,吸室负压1.6 k Pa时,（1-3）粒/穴概率在93%～97%之间变化。试验结果显示安装挡种装置后能控制＂飞种＂的跌落范围,并使部分＂飞种＂落回充种室内,从而提高排种器排种精度。
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. K19972011 and 10171058) and the Natural Science Foundation of Inner Mongolia (Grant No. 2001-0901-06).
文摘The complex method of the plane elasticity in 2D quasicrystal with point group 10 mm tenfold rotational symmetry is established. First displacement potential function in the quasicrystal is represented by four analytic functions. Then by utilizing the properties of analytic function and through a great deal of derivation, the complex representations of stresses and displacementscomponents of phonon fields and phason fields in the quasicrystal are given, which are the theo-retical foundation for this method. From this theory, and by the help of conformal transformations in the theory of complex function, the problems of elliptic hole in the quasicrystal are solved. Its spe-cial cases are the solutions of well-known crack problem. Meanwhile, the results show that even if under the self-counterbalance force in the quasicrystal plane with elliptic hole, the stress compo-nents of phonon fields are also related to material constants of the quasicrystal when the phonon fields and phason fields are coupled, which is another distinctive difference from the properties of classical elastic theory. Besides, the present work is generalization and application of the complex method in the classical elastic theory established by Muskhelishvili to 2D quasicrystal. As in the classical elastic theory, if only conformal transformation from the quasicrystal plane to unit circle isfound, any holey and crack problem in the quasicrystal plane could be solved.
