Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport...Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.展开更多
A crosshead slipper-guide system,which bears a significant thrust force,is an essential friction pair in low-speed marine diesel engines.Owing to the low moving speed of the crosshead slipper during engine startup,it ...A crosshead slipper-guide system,which bears a significant thrust force,is an essential friction pair in low-speed marine diesel engines.Owing to the low moving speed of the crosshead slipper during engine startup,it is difficult to form good hydrodynamic lubrication between the crosshead slipper and guide.Therefore,a detailed analysis of the crosshead slipper during engine startup is needed.In this study,a new transient tribo-dynamic model for a crosshead slipper during the engine startup process is presented.The model consists of a mixed lubrication model of the crosshead slipper-guide and dynamic models of the piston assembly,crosshead assembly,connecting rod,and crankshaft.The tribo-dynamic performances of the crosshead slipper during startup and under the rated conditions were simulated and compared.The results show that the tribo-dynamics of the crosshead slipper during the startup process are significantly different from those under the rated conditions.Some measures beneficial for the low friction of a crosshead slipper-guide under the rated conditions may significantly increase the friction loss of the crosshead slipper-guide system during the startup process.展开更多
Flexible perovskite solar cells(PSCs)have drawn increasing attention due to their promising applications for wearable electronics and aerospace applications.However,the efficiency and stability of flexible PSCs still ...Flexible perovskite solar cells(PSCs)have drawn increasing attention due to their promising applications for wearable electronics and aerospace applications.However,the efficiency and stability of flexible PSCs still lag behind their rigid counterparts.Here,we use N,N-dimethyl acrylamide(DMAA)to in situ synthesize cross-linking polymer for flexible Sn–Pb mixed PSCs.DMAA can gather at grain boundary as a scaffold to regulate the crystallization of perovskite and reduce defects.The rigid and flexible Sn–Pb mixed PSCs showed efficiencies of 16.44%and 15.44%,respectively.In addition,the flexible Sn–Pb mixed PSCs demonstrated excellent bending durability,which retained over 80%of the original efficiency after 5000 bending cycles at a radius of 5 mm.展开更多
基金the Zernike Institute for Advanced Materials for the startup fundsChina Scholarship Council(201606340158)。
文摘Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.
基金This study was supported by the Research Project of High Technological Vessels:Development of Low Speed Marine Engines(Grant No.MC-201501-D01-03)the National Natural Science Foundation of China(Grant No.51875344).
文摘A crosshead slipper-guide system,which bears a significant thrust force,is an essential friction pair in low-speed marine diesel engines.Owing to the low moving speed of the crosshead slipper during engine startup,it is difficult to form good hydrodynamic lubrication between the crosshead slipper and guide.Therefore,a detailed analysis of the crosshead slipper during engine startup is needed.In this study,a new transient tribo-dynamic model for a crosshead slipper during the engine startup process is presented.The model consists of a mixed lubrication model of the crosshead slipper-guide and dynamic models of the piston assembly,crosshead assembly,connecting rod,and crankshaft.The tribo-dynamic performances of the crosshead slipper during startup and under the rated conditions were simulated and compared.The results show that the tribo-dynamics of the crosshead slipper during the startup process are significantly different from those under the rated conditions.Some measures beneficial for the low friction of a crosshead slipper-guide under the rated conditions may significantly increase the friction loss of the crosshead slipper-guide system during the startup process.
基金funded financially by the National Natural Science Foundation of China(62204114,62075094,62205143)Natural Science Foundation of Jiangsu Province(BK20211537).
文摘Flexible perovskite solar cells(PSCs)have drawn increasing attention due to their promising applications for wearable electronics and aerospace applications.However,the efficiency and stability of flexible PSCs still lag behind their rigid counterparts.Here,we use N,N-dimethyl acrylamide(DMAA)to in situ synthesize cross-linking polymer for flexible Sn–Pb mixed PSCs.DMAA can gather at grain boundary as a scaffold to regulate the crystallization of perovskite and reduce defects.The rigid and flexible Sn–Pb mixed PSCs showed efficiencies of 16.44%and 15.44%,respectively.In addition,the flexible Sn–Pb mixed PSCs demonstrated excellent bending durability,which retained over 80%of the original efficiency after 5000 bending cycles at a radius of 5 mm.
