Based on the ABAQUS/Explicit code,A 3D elastic-plastic and coupled thermo-mechanical FE model of radial ring rolling of AZ31 Magnesium alloy has been proposed to analyze the influence of rotational speed of driver rol...Based on the ABAQUS/Explicit code,A 3D elastic-plastic and coupled thermo-mechanical FE model of radial ring rolling of AZ31 Magnesium alloy has been proposed to analyze the influence of rotational speed of driver roll to study the inhomogeneity distribution of strain and temperature,fishtail coefficient,rolling force parameters.The results show that:(1)when the rotational speed of driver roll n increases,the strain distribution of the rolled ring becomes less homogeneous,and the temperature distribution more homogeneous yet,and leading to an optimal n value;(2)the fishtail coefficient firstly decreases,then increases with the increase of n;(3)the rolling force,contact area and rolling moment gradually descend with the increase of n.展开更多
Two new conjugated copolymers,PBDT-T6-TTF and PBDT-T12-TTF,were derived from a novel 4-fluorobenzoyl thienothiophene(TTF).In addition,two types of benzodithiophene(BDT)units with 2,3-dihexylthienyl(T6)and 2,3-didodecy...Two new conjugated copolymers,PBDT-T6-TTF and PBDT-T12-TTF,were derived from a novel 4-fluorobenzoyl thienothiophene(TTF).In addition,two types of benzodithiophene(BDT)units with 2,3-dihexylthienyl(T6)and 2,3-didodecylthienyl(T12)substituents,respectively,were successfully synthesized.The effect of the dual two-dimensional(2D)substitutions of the building blocks upon the optoelectronic properties of the polymers was investigated.Generally,the two polymers exhibited good solubility and broad absorption,showing similar optical band gaps of^1.53 e V.However,PBDT-T6-TTF with its shorter alkyl chain length possessed a larger extinction coefficient in thin solid film.The highest occupied molecular orbital(HOMO)level of PBDT-T6-TTF was located at–5.38 e V while that of PBDT-T12-TTF was at–5.51 e V.In space charge-limitedcurrent(SCLC)measurement,PBDT-T6-TTF and PBDT-T12-TTF displayed respective hole mobilities of 3.0×10–4 and1.6×10–5 cm2 V1 s1.In polymer solar cells,PBDT-T6-TTF and PBDT-T12-TTF showed respective power conversion efficiencies(PCEs)of 2.86%and 1.67%.When 1,8-diiodooctane(DIO)was used as the solvent additive,the PCE of PBDT-T6-TTF was remarkably elevated to 4.85%,but the use of DIO for the PBDT-T12-TTF-blend film resulted in a lower PCE of 0.91%.Atomic force microscopy(AFM)indicated that the superior efficiency of PBDT-T6-TTF with 3%DIO(v/v)should be related to the better continuous phase separation of the blend film.Nevertheless,the morphology of the PBDT-T12-TTF deteriorated when the 3%DIO(v/v)was added.Our results suggest that the alkyl-chain length on the 2D BDT units play an important role in determining the optoelectronic properties of dual 2D BDT-TT-based polymers.展开更多
A series of novel acceptor-pended conjugated polymers featuring a newly developed carbazole-derived unit are designed and synthesized. The relationships between chemical structure and optoelectronic properties of the ...A series of novel acceptor-pended conjugated polymers featuring a newly developed carbazole-derived unit are designed and synthesized. The relationships between chemical structure and optoelectronic properties of the polymers are systematically investigated.The control of UV-Vis absorption spectra and energy levels in resulting polymers are achieved by introducing suitable pended acceptor units. The photovoltaic properties of the resulting polymers are evaluated by blending the polymers with(6,6)-phenyl-C71-butyric acid methyl ester. The resulting solar cells exhibit moderate performances with high open-circuit voltage. Charge transport properties and morphology were investigated to understand the performance of corresponding solar cells.展开更多
基金The authors are grateful for the financial support of Project Supported by:Chongqing Municipal Engineering Research Center of Institutions of Higher Education(cstc2011ptgc70007)Project Supported by Program for Innovation Team Building at Institutions of Higher Education in Chongqing(201028)Achievement Transfer Program of Institutions of Higher Education in Chongqing(kjzh11221).
文摘Based on the ABAQUS/Explicit code,A 3D elastic-plastic and coupled thermo-mechanical FE model of radial ring rolling of AZ31 Magnesium alloy has been proposed to analyze the influence of rotational speed of driver roll to study the inhomogeneity distribution of strain and temperature,fishtail coefficient,rolling force parameters.The results show that:(1)when the rotational speed of driver roll n increases,the strain distribution of the rolled ring becomes less homogeneous,and the temperature distribution more homogeneous yet,and leading to an optimal n value;(2)the fishtail coefficient firstly decreases,then increases with the increase of n;(3)the rolling force,contact area and rolling moment gradually descend with the increase of n.
基金financially supported by the National Natural Science Foundation of China(21225418 and 51173048)the National Basic Research Program of China(2013CB834705 and 2014CB643505)GDUPS(2013)
文摘Two new conjugated copolymers,PBDT-T6-TTF and PBDT-T12-TTF,were derived from a novel 4-fluorobenzoyl thienothiophene(TTF).In addition,two types of benzodithiophene(BDT)units with 2,3-dihexylthienyl(T6)and 2,3-didodecylthienyl(T12)substituents,respectively,were successfully synthesized.The effect of the dual two-dimensional(2D)substitutions of the building blocks upon the optoelectronic properties of the polymers was investigated.Generally,the two polymers exhibited good solubility and broad absorption,showing similar optical band gaps of^1.53 e V.However,PBDT-T6-TTF with its shorter alkyl chain length possessed a larger extinction coefficient in thin solid film.The highest occupied molecular orbital(HOMO)level of PBDT-T6-TTF was located at–5.38 e V while that of PBDT-T12-TTF was at–5.51 e V.In space charge-limitedcurrent(SCLC)measurement,PBDT-T6-TTF and PBDT-T12-TTF displayed respective hole mobilities of 3.0×10–4 and1.6×10–5 cm2 V1 s1.In polymer solar cells,PBDT-T6-TTF and PBDT-T12-TTF showed respective power conversion efficiencies(PCEs)of 2.86%and 1.67%.When 1,8-diiodooctane(DIO)was used as the solvent additive,the PCE of PBDT-T6-TTF was remarkably elevated to 4.85%,but the use of DIO for the PBDT-T12-TTF-blend film resulted in a lower PCE of 0.91%.Atomic force microscopy(AFM)indicated that the superior efficiency of PBDT-T6-TTF with 3%DIO(v/v)should be related to the better continuous phase separation of the blend film.Nevertheless,the morphology of the PBDT-T12-TTF deteriorated when the 3%DIO(v/v)was added.Our results suggest that the alkyl-chain length on the 2D BDT units play an important role in determining the optoelectronic properties of dual 2D BDT-TT-based polymers.
基金supported by the Ministry of Science and Technology(2014CB643501)the National Natural Science Foundation of China(21520102006,21490573,51361165301)the Guangdong Natural Science Foundation(S2012030006232)
文摘A series of novel acceptor-pended conjugated polymers featuring a newly developed carbazole-derived unit are designed and synthesized. The relationships between chemical structure and optoelectronic properties of the polymers are systematically investigated.The control of UV-Vis absorption spectra and energy levels in resulting polymers are achieved by introducing suitable pended acceptor units. The photovoltaic properties of the resulting polymers are evaluated by blending the polymers with(6,6)-phenyl-C71-butyric acid methyl ester. The resulting solar cells exhibit moderate performances with high open-circuit voltage. Charge transport properties and morphology were investigated to understand the performance of corresponding solar cells.
