We develop a dual porous （DP） TiO2 film for the electron transporting layer （ETL） in carbon cathode based perovskite solar cells （C-PSCs）. The DP TiO2 film was synthesized via a facile PS-templated method with t...We develop a dual porous （DP） TiO2 film for the electron transporting layer （ETL） in carbon cathode based perovskite solar cells （C-PSCs）. The DP TiO2 film was synthesized via a facile PS-templated method with the thickness being controlled by the spin-coating speed. It was found that there is an optimum DP TiO2 film thickness for achieving an effective ETL, a suitable perovskite]TiO2 interface, an efficient light harvester and thus a high performance C-PSC. In particular, such a DP TiO2 film can act as a scaffold for complete-filling of the pores with perovskite and for forming high-quality perovskite crystals that are seamlessly interfaced with Ti02 to enhance interracial charge injection. Leveraging the unique advantages of DP TiO2 ETL, together with a dense-packed and pinhole-free TiO2 compact layer, PCE of the C-PSCs has reached 9.81% with good stability.展开更多
This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear imp...This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.展开更多
Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable dep...Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.展开更多
All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite sol...All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite solar cells(PSCs)was limited by severe nonradiative charge recombination due to high defect density at the grain boundary and surface of perovskitefilms.To address this issue,a pyrrolidinium iodide(PyI)molecule was introduced to modify the surface and grain boundary of CsPbI_(3) perovskitefilms to passivate defects,which improves the quality of CsPbI_(3) perovskitefilms as well as induces the generation of a quasi-2D Py_(2)CsPb_(2)I_(7) capping layer between per-ovskite layer and hole transport layer.Such quasi-2D Py_(2)CsPb_(2)I_(7) capping layer optimizes interface contact between CsPbI_(3) perovskite layer and hole transport layer and blocks the electron transfer from CsPbI_(3) perovskite photoactive layer to the hole transport layer.As a result,the performance of CsPbI_(3) PSCs is well improved to 17.87%for power conversion efficiency(PCE)with an ultra-high fill factor(FF)of 0.84.In addition,the PyI mole-cule modified CsPbI_(3) perovskite devices exhibit excellent stability,which remains its initial PCE almost unchanged after aging for 35 days under the dry air atmosphere(temperature:20℃–30℃,control relative humid-ity(RH):<10%).展开更多
[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was u...[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was used to study the effects of adding different concentrations of humic acid,DMPP and their compound on the growth of maize. [Results] Both humic acid and DMPP could increase plant height,stem diameter,SPAD and biomass of maize. The effect of adding 10 kg of humic acid per t was better than that adding 5 kg,and biomass increased by 5. 4% and 3. 3% compared with CK. The effect of adding 1 kg of DMPP was better than that adding 0. 5 kg,and biomass increased by 5. 7% and 2. 7% compared with CK. The compound application of the 2 improved the fertilizer efficiency. The best treatment was 5‰ humic acid ＋ 1 ‰ DMPP,which could increase plant height,stem diameter,SPAD,and dry weight by 8. 1%,12. 3%,10. 6%,and 10. 7%,respectively,and it also had lower economic costs compared with the compounding application of 10‰ humic acid ＋ 1‰ DMPP.[Conclusions]The 5‰ humic acid ＋ 1 ‰ DMPP compound fertilizer formula was more suitable for application in maize production.展开更多
Inorganic CsPbI_(3)perovskite has exhibited great application potential in perovskite solar cells(PSCs)due to its suitable optical bandgap and high chemical stability.However,the perovskite phases of CsPbI_(3)are not ...Inorganic CsPbI_(3)perovskite has exhibited great application potential in perovskite solar cells(PSCs)due to its suitable optical bandgap and high chemical stability.However,the perovskite phases of CsPbI_(3)are not stable at room temperature,where they transition to non-perovskite phases.Humidity or water has been thought to be the primary factor inducing this phase transition,which should be avoided throughout the procedure of film and device processing.Surprisingly,the present study indicates that preparing a precursor solution in humid air is beneficial to the growth of high-quality CsPbI_(3)perovskite to enhance device performance.It is demonstrated that the incorporation of H2O in the precursor solution from humid air or by intentional addition significantly changes the composition of coordination compounds and increases the amount of low iodine coordination complexes.As a result,the crystallization of dimethylammonium lead iodide(DMAPbI_(3))intermediate is suppressed well,which accelerates its subsequent conversion to CsPbI_(3)perovskite.Consequently,an oriented CsPbI_(3)perovskite film with improved crystallinity and lower defect density is obtained.Most importantly,carbon-based PSCs(C-PSCs)based on the CsPbI_(3)perovskite film achieve an efficiency of 16.05%,a new record for inorganic C-PSCs.展开更多
Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the pr...Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.展开更多
Epithelial–mesenchymal transition(EMT)is recognized as a driving force of cancer cell metastasis and drug resistance,two leading causes of cancer recurrence and cancer-related death.It is,therefore,logical in cancer ...Epithelial–mesenchymal transition(EMT)is recognized as a driving force of cancer cell metastasis and drug resistance,two leading causes of cancer recurrence and cancer-related death.It is,therefore,logical in cancer therapy to target the EMT switch to prevent such cancer metastasis and recurrence.Previous reports have indicated that growth factors(such as epidermal growth factor and fibroblast growth factor)and cytokines(such as the transforming growth factor beta(TGF-β)family)are major stimulators of EMT.However,the mechanisms underlying EMT initiation and progression remain unclear.Recently,emerging evidence has suggested that reactive oxygen species(ROS),important cellular secondary messengers involved in diverse biological events in cancer cells,play essential roles in the EMT process in cancer cells by regulating extracellular matrix(ECM)remodeling,cytoskeleton remodeling,cell–cell junctions,and cell mobility.Thus,targeting EMT by manipulating the intracellular redox status may hold promise for cancer therapy.Herein,we will address recent advances in redox biology involved in the EMT process in cancer cells,which will contribute to the development of novel therapeutic strategies by targeting redox-regulated EMT for cancer treatment.展开更多
Organic-inorganic perovskite solar cells （PSCs） have attracted intense attention in the last few years due to the phenomenal increase in power conversion efficiency （PCE）, but their low stability has greatly hinde...Organic-inorganic perovskite solar cells （PSCs） have attracted intense attention in the last few years due to the phenomenal increase in power conversion efficiency （PCE）, but their low stability has greatly hindered their practical application. By removing unstable hole transport materials （HTM）, the device stability of HTM-free PSCs has been greatly improved. However, the PCE has largely lagged behind those of HTM-based PSCs. We contend that deposition of high-quality perovskite into a thick scaffold is the key to achieving high-performance, HTM-free PSCs. Indeed, a few deposition methods have been used to successfully deposit a high-quality perovskite layer into a relatively thick TiO2 scaffold, hence producing PSCs with relatively high PCEs. In this review, we will introduce the basic working principle of HTM-free PSCs and analyze the important role of thick TiO2 scaffold. Most importantly, the problems of the conventional perovskite deposition methods in thick TiO2 scaffold will be examined and some recent successful deposition methods will be surveyed. Finally, we will draw conclusions and highlight some promising research directions for HTM-free PSCs.展开更多
This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneo...This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneously achieving high-performance, high stability and low-cost PSCs. Here the thin P3HT modifier acts as an electron blocker to inhibit electron transfer into CNTs and a hydrophobic polymer binder to tightly cross-link the CNTs together to compact the carbon electrode film and greatly stabilize the solar cell. On the other hand, the presence of CNTs greatly improve the conductivity of P3HT. By optimizing the concentration of the P3HT modifier （2 mg/mL）, we have improved the power conversion efficiencies （PCEs） of CNTs@P3HT based PSCs up to 13.43% with an average efficiency of 12.54%, which is much higher than the pure CNTs based PSCs （best PCE 10.59%） and the sandwich-type P3HT/CNTs based PSCs （best PCE 9.50%）. In addition, the hysteresis of the CNTs@P3HT based PSCs is remarkably reduced due to the intimate interface between the perovskite and CNTs@P3HT electrodes. Degradation of the CNTs@ P3HT based PSCs is also strongly retarded as compared to cells employing the pure CNTs electrode when exposed to the ambient condition of 20%- 40% humidity.展开更多
基金supported by the HK Innovation and Technology Fund (ITS/004/14)the HK-RGC General Research Funds (GRE No. HKUST 606511)
文摘We develop a dual porous （DP） TiO2 film for the electron transporting layer （ETL） in carbon cathode based perovskite solar cells （C-PSCs）. The DP TiO2 film was synthesized via a facile PS-templated method with the thickness being controlled by the spin-coating speed. It was found that there is an optimum DP TiO2 film thickness for achieving an effective ETL, a suitable perovskite]TiO2 interface, an efficient light harvester and thus a high performance C-PSC. In particular, such a DP TiO2 film can act as a scaffold for complete-filling of the pores with perovskite and for forming high-quality perovskite crystals that are seamlessly interfaced with Ti02 to enhance interracial charge injection. Leveraging the unique advantages of DP TiO2 ETL, together with a dense-packed and pinhole-free TiO2 compact layer, PCE of the C-PSCs has reached 9.81% with good stability.
文摘This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.
基金supported by the National Natural Science Foundation of China(U2001217,22261160370 and 21972006)Guangdong-Hong Kong-Macao Joint Innovation Foundation(2021A0505110003)+1 种基金Shenzhen Basic Research(JCYJ20220818101018038 and JCYJ20200109110628172)Guangdong Province Regional Joint Innovation Foundation(2020B1515120039)。
文摘Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.
基金National Natural Science Foundation of China,Grant No.21875013,H.N.ChenBeijing Natural Science Foundation,Grant No.2182031,H.N.Chen.
文摘All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite solar cells(PSCs)was limited by severe nonradiative charge recombination due to high defect density at the grain boundary and surface of perovskitefilms.To address this issue,a pyrrolidinium iodide(PyI)molecule was introduced to modify the surface and grain boundary of CsPbI_(3) perovskitefilms to passivate defects,which improves the quality of CsPbI_(3) perovskitefilms as well as induces the generation of a quasi-2D Py_(2)CsPb_(2)I_(7) capping layer between per-ovskite layer and hole transport layer.Such quasi-2D Py_(2)CsPb_(2)I_(7) capping layer optimizes interface contact between CsPbI_(3) perovskite layer and hole transport layer and blocks the electron transfer from CsPbI_(3) perovskite photoactive layer to the hole transport layer.As a result,the performance of CsPbI_(3) PSCs is well improved to 17.87%for power conversion efficiency(PCE)with an ultra-high fill factor(FF)of 0.84.In addition,the PyI mole-cule modified CsPbI_(3) perovskite devices exhibit excellent stability,which remains its initial PCE almost unchanged after aging for 35 days under the dry air atmosphere(temperature:20℃–30℃,control relative humid-ity(RH):<10%).
基金Supported by the Research and Demonstration of Key Technologies for Crop Cost-Effective and High-Yield Production of the Project for Industry Leading Talents of Taishan(Lukezi[2016]NO.16)
文摘[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was used to study the effects of adding different concentrations of humic acid,DMPP and their compound on the growth of maize. [Results] Both humic acid and DMPP could increase plant height,stem diameter,SPAD and biomass of maize. The effect of adding 10 kg of humic acid per t was better than that adding 5 kg,and biomass increased by 5. 4% and 3. 3% compared with CK. The effect of adding 1 kg of DMPP was better than that adding 0. 5 kg,and biomass increased by 5. 7% and 2. 7% compared with CK. The compound application of the 2 improved the fertilizer efficiency. The best treatment was 5‰ humic acid ＋ 1 ‰ DMPP,which could increase plant height,stem diameter,SPAD,and dry weight by 8. 1%,12. 3%,10. 6%,and 10. 7%,respectively,and it also had lower economic costs compared with the compounding application of 10‰ humic acid ＋ 1‰ DMPP.[Conclusions]The 5‰ humic acid ＋ 1 ‰ DMPP compound fertilizer formula was more suitable for application in maize production.
基金supported by the National Natural Science Foundation of China(21875013)the Beijing Natural Science Foundation(2182031).
文摘Inorganic CsPbI_(3)perovskite has exhibited great application potential in perovskite solar cells(PSCs)due to its suitable optical bandgap and high chemical stability.However,the perovskite phases of CsPbI_(3)are not stable at room temperature,where they transition to non-perovskite phases.Humidity or water has been thought to be the primary factor inducing this phase transition,which should be avoided throughout the procedure of film and device processing.Surprisingly,the present study indicates that preparing a precursor solution in humid air is beneficial to the growth of high-quality CsPbI_(3)perovskite to enhance device performance.It is demonstrated that the incorporation of H2O in the precursor solution from humid air or by intentional addition significantly changes the composition of coordination compounds and increases the amount of low iodine coordination complexes.As a result,the crystallization of dimethylammonium lead iodide(DMAPbI_(3))intermediate is suppressed well,which accelerates its subsequent conversion to CsPbI_(3)perovskite.Consequently,an oriented CsPbI_(3)perovskite film with improved crystallinity and lower defect density is obtained.Most importantly,carbon-based PSCs(C-PSCs)based on the CsPbI_(3)perovskite film achieve an efficiency of 16.05%,a new record for inorganic C-PSCs.
基金supported by the National Key Research and Development Program of China (2018YFA0209600)Shenzhen Peacock Plan (KQTD2016053015544057)Nanshan Pilot Plan (LHTD20170001)
文摘Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.
基金This work was supported by grants from the National 973 Basic Research Program of China(2013CB911300)the Chinese NSFC(81430071,81672381 and 81602194)the National Key Research and development program of China(2016YFC1200203).
文摘Epithelial–mesenchymal transition(EMT)is recognized as a driving force of cancer cell metastasis and drug resistance,two leading causes of cancer recurrence and cancer-related death.It is,therefore,logical in cancer therapy to target the EMT switch to prevent such cancer metastasis and recurrence.Previous reports have indicated that growth factors(such as epidermal growth factor and fibroblast growth factor)and cytokines(such as the transforming growth factor beta(TGF-β)family)are major stimulators of EMT.However,the mechanisms underlying EMT initiation and progression remain unclear.Recently,emerging evidence has suggested that reactive oxygen species(ROS),important cellular secondary messengers involved in diverse biological events in cancer cells,play essential roles in the EMT process in cancer cells by regulating extracellular matrix(ECM)remodeling,cytoskeleton remodeling,cell–cell junctions,and cell mobility.Thus,targeting EMT by manipulating the intracellular redox status may hold promise for cancer therapy.Herein,we will address recent advances in redox biology involved in the EMT process in cancer cells,which will contribute to the development of novel therapeutic strategies by targeting redox-regulated EMT for cancer treatment.
文摘Organic-inorganic perovskite solar cells （PSCs） have attracted intense attention in the last few years due to the phenomenal increase in power conversion efficiency （PCE）, but their low stability has greatly hindered their practical application. By removing unstable hole transport materials （HTM）, the device stability of HTM-free PSCs has been greatly improved. However, the PCE has largely lagged behind those of HTM-based PSCs. We contend that deposition of high-quality perovskite into a thick scaffold is the key to achieving high-performance, HTM-free PSCs. Indeed, a few deposition methods have been used to successfully deposit a high-quality perovskite layer into a relatively thick TiO2 scaffold, hence producing PSCs with relatively high PCEs. In this review, we will introduce the basic working principle of HTM-free PSCs and analyze the important role of thick TiO2 scaffold. Most importantly, the problems of the conventional perovskite deposition methods in thick TiO2 scaffold will be examined and some recent successful deposition methods will be surveyed. Finally, we will draw conclusions and highlight some promising research directions for HTM-free PSCs.
文摘This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneously achieving high-performance, high stability and low-cost PSCs. Here the thin P3HT modifier acts as an electron blocker to inhibit electron transfer into CNTs and a hydrophobic polymer binder to tightly cross-link the CNTs together to compact the carbon electrode film and greatly stabilize the solar cell. On the other hand, the presence of CNTs greatly improve the conductivity of P3HT. By optimizing the concentration of the P3HT modifier （2 mg/mL）, we have improved the power conversion efficiencies （PCEs） of CNTs@P3HT based PSCs up to 13.43% with an average efficiency of 12.54%, which is much higher than the pure CNTs based PSCs （best PCE 10.59%） and the sandwich-type P3HT/CNTs based PSCs （best PCE 9.50%）. In addition, the hysteresis of the CNTs@P3HT based PSCs is remarkably reduced due to the intimate interface between the perovskite and CNTs@P3HT electrodes. Degradation of the CNTs@ P3HT based PSCs is also strongly retarded as compared to cells employing the pure CNTs electrode when exposed to the ambient condition of 20%- 40% humidity.
