Ni-Fe-based oxides are among the most promising catalysts developed to date for the bottleneck oxygen evolution reaction(OER)in water electrolysis.However,understanding and mastering the synergy of Ni and Fe remain ch...Ni-Fe-based oxides are among the most promising catalysts developed to date for the bottleneck oxygen evolution reaction(OER)in water electrolysis.However,understanding and mastering the synergy of Ni and Fe remain challenging.Herein,we report that the synergy between Ni and Fe can be tailored by crystal dimensionality of Ni,Fe-contained Ruddlesden-Popper(RP)-type perovskites(La_(0.125)Sr_(0.875))n+1(Ni_(0.25)Fe_(0.75))nO3n+1(n=1,2,3),where the material with n=3 shows the best OER performance in alkaline media.Soft X-ray absorption spectroscopy spectra before and after OER reveal that the material with n=3 shows enhanced Ni/Fe-O covalency to boost the electron transfer as compared to those with n=1 and n=2.Further experimental investigations demonstrate that the Fe ion is the active site and the Ni ion is the stable site in this system,where such unique synergy reaches the optimum at n=3.Besides,as n increases,the proportion of unstable rock-salt layers accordingly decreases and the leaching of ions(especially Sr^(2+))into the electrolyte is suppressed,which induces a decrease in the leaching of active Fe ions,ultimately leading to enhanced stability.This work provides a new avenue for rational catalyst design through the dimensional strategy.展开更多
[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were...[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.展开更多
Molybdenum carbide(MoxC)with variable phase structure possesses flexible hydrogen-binding energy(HBE),which is a promising hydrogen evolution reaction(HER)catalyst.Herein,a hybrid multiphase MoxC freestanding film cou...Molybdenum carbide(MoxC)with variable phase structure possesses flexible hydrogen-binding energy(HBE),which is a promising hydrogen evolution reaction(HER)catalyst.Herein,a hybrid multiphase MoxC freestanding film coupled with Co3Mo(CM/MoxC@NC)is synthesized through the electrospinning method supplemented by the heteroatom incorporation.CM/MoxC@NC surpasses its pure phase counterparts and exhibits remarkable catalytic activity at 114mV to deliver a current density of 10mA cm^(−2) in acid,which is among the first-rate level performance reported for MoxC-based catalysts.The subsequent ex situ and in situ characterizations reveal a phase transition mechanism based on self-catalysis that CoOx depletes the coordinated C ofα-MoC via the interaction,which realizes the assembly of weak HBEα-MoC and strong HBEβ-Mo2C,and the enhanced utilization of active materials as well.The multiple structures with optimal HBE are in favor of the stepwise reactions of HER,as the study of the correlation between HBE and phase structure revealed.This study discloses the underlying phase transition mechanism and highlights the HBE–structure relationship that should be considered for catalyst design.展开更多
In this paper, transverse vibration of an axially moving beam supported by a viscoelastic foundation is analyzed by a complex modal analysis method. The equation of motion is developed based on the generalized Hamilto...In this paper, transverse vibration of an axially moving beam supported by a viscoelastic foundation is analyzed by a complex modal analysis method. The equation of motion is developed based on the generalized Hamilton＇s principle. Eigenvalues and eigenfunctions are semi-analytically obtained. The governing equation is represented in a canonical state space form, which is defined by two matrix differential operators. The orthogonality of the eigenfunctions and the adjoint eigenfunctions is used to decouple the system in the state space. The responses of the system to arbitrary external excitation and initial conditions are expressed in the modal expansion. Numerical examples are presented to illustrate the proposed approach. The effects of the foundation parameters on free and forced vibration are examined.展开更多
In this work, we successfully synthesized bicrystalline anatase/TiO2（B） nanofibre and used it as active substrate for surface-enhanced Raman scattering （SERS） applications. The bicrystalline structured TiO2 substr...In this work, we successfully synthesized bicrystalline anatase/TiO2（B） nanofibre and used it as active substrate for surface-enhanced Raman scattering （SERS） applications. The bicrystalline structured TiO2 substrates provide additional charge transfer across the anatase-TiO2（B） interface and thus enhanced activity compared to the pure single crystalline phase. With an effort to further increase the sensitivity of SERS, nitrogen element was doped into bicrystalline anatase/TiO2（B） nanofibres （N-TiO2） and higher SERS enhancement was achieved. The nitrogen content was controlled by tuning the calcination temperature of titanate precursor at 500, 600 and 700℃, respectively. The sample calcined at 600℃ （NT600） acquires the highest percentage of nitrogen element due to its open pore structure that facilitates the diffusion of nitrogen during calcination. Raman intensity depends on the amount of nitrogen doping, thus NT600 exhibited the best SERS activity. The doped nitrogen in TiO2 facilitates the charge transfer between TiO2 and probing molecules and thus suppresses the electron-hole recombination. This work provides a new perspective on the design of efficient TiO2 SERS active substrate and is expected to be valuable for adsorbate detection on semiconductor surface.展开更多
At present,Zibo is in the critical stage of rural revitalization.In order to accelerate the development of modern vegetable industry and promote rural revitalization,Zibo City Vegetable Office organized special person...At present,Zibo is in the critical stage of rural revitalization.In order to accelerate the development of modern vegetable industry and promote rural revitalization,Zibo City Vegetable Office organized special personnel to carry out this survey.This survey report comprehensively analyzed the current development situation of vegetable industry in Zibo City:the industrial structure has been constantly optimized,the standardization has made new breakthroughs,the project implementation has achieved remarkable results,and the technological level has realized constant improvement.It found out the problems that restrict the development of modern vegetables in Zibo City:small-scale scattered planting accounts for a large proportion,vegetable output rate is not high,product quality supervision is difficult,and some vegetable farmers are low in technological quality.In view of the current situation and existing problems of vegetable development in Zibo City,it came up with recommendations for accelerating the development of modern vegetable industry,including driving through project leading,to achieving innovative development,accelerating scientific and technological training and strengthening talent support,developing new organizations to promote industrial upgrading,strengthening quality supervision and improving vegetable quality,and industrial integration and development to expand and strengthen the vegetable industry.展开更多
[Objectives]This study was conducted for the purpose of widely using molecular biology techniques in the detection of seafood species.[Methods]In this study,such four kinds of seafood as fish,shrimps,crabs and shellfi...[Objectives]This study was conducted for the purpose of widely using molecular biology techniques in the detection of seafood species.[Methods]In this study,such four kinds of seafood as fish,shrimps,crabs and shellfish were used as samples to compare three DNA extraction methods,including Tiangen marine animal tissue genome extraction kit method(DP324)(a),SN/T 3589.6-2013/8.3(b)method and modified SN/T 3730.8-2013/8.1(c)method.The purity and concentrations of DNA and the amplification effects of real-time fluorescene PCR were compared.[Results]The three methods had different extraction effects while satisfying the real-time fluorescent PCR detection.The DNA templates extracted by the SN/T 3730.8-2013/8.1 standard method had higher purity and concentrations,and showed clearer bands in gel electrophoresis,indicating that the method has less effect on real-time fluorescent PCR and less inhibition,and can meet the detection needs of the four types of seafood,including fish,shrimps,crabs and shellfish.[Conclusions]This study provides a theoretical basis for the detection of seafood animal-derived components.展开更多
In view of the occurrence and aggravation of diseases and pests of horticultural crops,the management process should follow the basic policy of"prevention first,comprehensive control".Starting from the ecolo...In view of the occurrence and aggravation of diseases and pests of horticultural crops,the management process should follow the basic policy of"prevention first,comprehensive control".Starting from the ecological system,agricultural,biological,physical and chemical means should be comprehensively applied to control diseases and pests below the economic injury level.展开更多
With the rapid development of modern information technology, digital technology has gradually penetrated into all fields and links of the agricultural industry. Digital orchard reflects the comprehensive application o...With the rapid development of modern information technology, digital technology has gradually penetrated into all fields and links of the agricultural industry. Digital orchard reflects the comprehensive application of digital technology in orchard management. This study surveys and analyzes the current development of digital orchard, clarifies the development status and existing problems, and comes up with reasonable recommendations, to provide a certain reference and guidance for the construction of digital orchard in Zibo City of Shandong Province.展开更多
[Objectives]The study aims to verify the application effect of silicon-containing water-soluble fertilizer on fast vegetables.[Methods]Two vegetable crops,rape and lettuce,were studied,and three treatments were set up...[Objectives]The study aims to verify the application effect of silicon-containing water-soluble fertilizer on fast vegetables.[Methods]Two vegetable crops,rape and lettuce,were studied,and three treatments were set up,including treatment 1(conventional fertilization+foliar spraying of silicon-containing water-soluble fertilizer,treatment 2(conventional fertilization+foliar spraying of the same amount of clear water),and treatment 3(conventional fertilization).[Results]The yield of lettuce and rape in treatment 1 increased by 15.1%and 8.6%,respectively;compared with treatment 3,the yield of lettuce and rape rose by 18.6%and 10.9%,respectively.Variance analysis shows that the F values of lettuce and rape were 20.938 and 35.372,respectively,and the differences among various treatments were extremely significant.[Conclusions]The application of silicon-containing water-soluble fertilizer on lettuce and rape significantly increased their yield.展开更多
Here we firstly report a series of new deep eutectic solvents(DESs) induced by small amounts of crown ether complex and mainly formed by polyethylene glycol. These DESs not only presented the ultra-deep extraction of ...Here we firstly report a series of new deep eutectic solvents(DESs) induced by small amounts of crown ether complex and mainly formed by polyethylene glycol. These DESs not only presented the ultra-deep extraction of non-basic N-compounds from fuel oils, but also opened up the possibility of other new applications in chemistry and materials science.展开更多
Cysteine(Cys)plays a pivotal role in many physiological and pathological processes,including detoxification and protein synthesis.The abnormal levels of Cys are linked to many diseases.In this study,a novel red-emitti...Cysteine(Cys)plays a pivotal role in many physiological and pathological processes,including detoxification and protein synthesis.The abnormal levels of Cys are linked to many diseases.In this study,a novel red-emitting off-on fluorescent probe Cys-TCF was masterly constructed for discriminative detection of Cys.After a series of experimental assessment,Cys-TCF displayed higher selectivity and sensitivity for Cys over other biothilols with a low detection limit(0.04μmol/L).More notably,the probe was also successfully applied to image Cys in live cells and live zebrafishes with low cytotoxicity.展开更多
Porous graphene(PG) has potential applications in numerous fields because of the existence of nanopores in the plane. In this study, porous graphene decorated silica microspheres(Sil-PG) were successfully fabricated b...Porous graphene(PG) has potential applications in numerous fields because of the existence of nanopores in the plane. In this study, porous graphene decorated silica microspheres(Sil-PG) were successfully fabricated by assembling PG onto the silica particles surface in deep eutectic solvents(DESs).Experimental results demonstrate that this new stationary phase can facilitate the separation of six sulfonamides compounds in hydrophilic chromatographic conditions. The successful synthesis of the SilPG stationary phase provides a basis for the application of porous graphene-modified materials as the stationary phase for liquid chromatography, and offers the possibility to broaden the application of PG in the field of chromatography.展开更多
The transverse vibration of an axially moving string supported by a viscoelastic foundation is analysed using the complex modal method. The equation of motion is developed using the generalized Hamilton principle. The...The transverse vibration of an axially moving string supported by a viscoelastic foundation is analysed using the complex modal method. The equation of motion is developed using the generalized Hamilton principle. The exact closed-form solution of eigenvalues and eigen- functions are obtained. The governing equation is represented in a canonical state space form defined by two matrix differential operators, and the eigenfunctions and adjoint eigenfunctions are proved to be orthogonal with respect to each operator. This orthogonality is applied so that the response to arbitrary external excitations and initial conditions can be expressed in modal expansion. Numerical examples are presented to validate the proposed approach.展开更多
The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D struct...The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D structure,which can cause the ion migration and the related defects.Here,we found that the in situ-grown perovskitoid TEAPbI_(3)layer on 3D MAPbI_(3)can inhibit the MA^(+)migration in a polar solvent,thus enhancing the thermal and moisture stability of perovskite films.The crystal structure and orientation of TEAPbI_(3)are reported for the first time by single crystal and synchrotron radiation analysis.The ultra-thin perovskitoid layer can reduce the trap states and accelerate photo-carrier diffusion in perovskite solar cells,as confirmed by ultra-fast spectroscopy.The power conversion efficiency of TEAPbI_(3)-MAPbI_(3)based solar cells increases from 18.87%to 21.79%with enhanced stability.This work suggests that passivation and stabilization by in situ-grown perovskitoid can be a promising strategy for efficient and stable perovskite solar cells.展开更多
基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2023A1515012878Natural Science Foundation of Anhui Province,Grant/Award Number:2008085ME134+2 种基金Australian Research Council Discovery Projects,Grant/Award Numbers:ARC DP200103315,ARC DP200103332Major Special Science and Technology Project of Anhui Province,Grant/Award Number:202103a07020007Key Research and Development Program of Anhui Province,Grant/Award Number:202104a05020057。
文摘Ni-Fe-based oxides are among the most promising catalysts developed to date for the bottleneck oxygen evolution reaction(OER)in water electrolysis.However,understanding and mastering the synergy of Ni and Fe remain challenging.Herein,we report that the synergy between Ni and Fe can be tailored by crystal dimensionality of Ni,Fe-contained Ruddlesden-Popper(RP)-type perovskites(La_(0.125)Sr_(0.875))n+1(Ni_(0.25)Fe_(0.75))nO3n+1(n=1,2,3),where the material with n=3 shows the best OER performance in alkaline media.Soft X-ray absorption spectroscopy spectra before and after OER reveal that the material with n=3 shows enhanced Ni/Fe-O covalency to boost the electron transfer as compared to those with n=1 and n=2.Further experimental investigations demonstrate that the Fe ion is the active site and the Ni ion is the stable site in this system,where such unique synergy reaches the optimum at n=3.Besides,as n increases,the proportion of unstable rock-salt layers accordingly decreases and the leaching of ions(especially Sr^(2+))into the electrolyte is suppressed,which induces a decrease in the leaching of active Fe ions,ultimately leading to enhanced stability.This work provides a new avenue for rational catalyst design through the dimensional strategy.
文摘[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.
基金This study was supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Molybdenum carbide(MoxC)with variable phase structure possesses flexible hydrogen-binding energy(HBE),which is a promising hydrogen evolution reaction(HER)catalyst.Herein,a hybrid multiphase MoxC freestanding film coupled with Co3Mo(CM/MoxC@NC)is synthesized through the electrospinning method supplemented by the heteroatom incorporation.CM/MoxC@NC surpasses its pure phase counterparts and exhibits remarkable catalytic activity at 114mV to deliver a current density of 10mA cm^(−2) in acid,which is among the first-rate level performance reported for MoxC-based catalysts.The subsequent ex situ and in situ characterizations reveal a phase transition mechanism based on self-catalysis that CoOx depletes the coordinated C ofα-MoC via the interaction,which realizes the assembly of weak HBEα-MoC and strong HBEβ-Mo2C,and the enhanced utilization of active materials as well.The multiple structures with optimal HBE are in favor of the stepwise reactions of HER,as the study of the correlation between HBE and phase structure revealed.This study discloses the underlying phase transition mechanism and highlights the HBE–structure relationship that should be considered for catalyst design.
基金Project supported by the State Key Program of the National Natural Science Foundation of China(No.11232009)the National Natural Science Foundation of China(Nos.11372171 and 11422214)
文摘In this paper, transverse vibration of an axially moving beam supported by a viscoelastic foundation is analyzed by a complex modal analysis method. The equation of motion is developed based on the generalized Hamilton＇s principle. Eigenvalues and eigenfunctions are semi-analytically obtained. The governing equation is represented in a canonical state space form, which is defined by two matrix differential operators. The orthogonality of the eigenfunctions and the adjoint eigenfunctions is used to decouple the system in the state space. The responses of the system to arbitrary external excitation and initial conditions are expressed in the modal expansion. Numerical examples are presented to illustrate the proposed approach. The effects of the foundation parameters on free and forced vibration are examined.
基金Supported by Chinese MOST 973 project(2013CB733501)the National Natural Science Foundation of China1(21136004,21476106,21606131)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Fundamental Research Funds for the Central Universities(30916011351)at Nanjing University of Science&Technology
文摘In this work, we successfully synthesized bicrystalline anatase/TiO2（B） nanofibre and used it as active substrate for surface-enhanced Raman scattering （SERS） applications. The bicrystalline structured TiO2 substrates provide additional charge transfer across the anatase-TiO2（B） interface and thus enhanced activity compared to the pure single crystalline phase. With an effort to further increase the sensitivity of SERS, nitrogen element was doped into bicrystalline anatase/TiO2（B） nanofibres （N-TiO2） and higher SERS enhancement was achieved. The nitrogen content was controlled by tuning the calcination temperature of titanate precursor at 500, 600 and 700℃, respectively. The sample calcined at 600℃ （NT600） acquires the highest percentage of nitrogen element due to its open pore structure that facilitates the diffusion of nitrogen during calcination. Raman intensity depends on the amount of nitrogen doping, thus NT600 exhibited the best SERS activity. The doped nitrogen in TiO2 facilitates the charge transfer between TiO2 and probing molecules and thus suppresses the electron-hole recombination. This work provides a new perspective on the design of efficient TiO2 SERS active substrate and is expected to be valuable for adsorbate detection on semiconductor surface.
文摘At present,Zibo is in the critical stage of rural revitalization.In order to accelerate the development of modern vegetable industry and promote rural revitalization,Zibo City Vegetable Office organized special personnel to carry out this survey.This survey report comprehensively analyzed the current development situation of vegetable industry in Zibo City:the industrial structure has been constantly optimized,the standardization has made new breakthroughs,the project implementation has achieved remarkable results,and the technological level has realized constant improvement.It found out the problems that restrict the development of modern vegetables in Zibo City:small-scale scattered planting accounts for a large proportion,vegetable output rate is not high,product quality supervision is difficult,and some vegetable farmers are low in technological quality.In view of the current situation and existing problems of vegetable development in Zibo City,it came up with recommendations for accelerating the development of modern vegetable industry,including driving through project leading,to achieving innovative development,accelerating scientific and technological training and strengthening talent support,developing new organizations to promote industrial upgrading,strengthening quality supervision and improving vegetable quality,and industrial integration and development to expand and strengthen the vegetable industry.
文摘[Objectives]This study was conducted for the purpose of widely using molecular biology techniques in the detection of seafood species.[Methods]In this study,such four kinds of seafood as fish,shrimps,crabs and shellfish were used as samples to compare three DNA extraction methods,including Tiangen marine animal tissue genome extraction kit method(DP324)(a),SN/T 3589.6-2013/8.3(b)method and modified SN/T 3730.8-2013/8.1(c)method.The purity and concentrations of DNA and the amplification effects of real-time fluorescene PCR were compared.[Results]The three methods had different extraction effects while satisfying the real-time fluorescent PCR detection.The DNA templates extracted by the SN/T 3730.8-2013/8.1 standard method had higher purity and concentrations,and showed clearer bands in gel electrophoresis,indicating that the method has less effect on real-time fluorescent PCR and less inhibition,and can meet the detection needs of the four types of seafood,including fish,shrimps,crabs and shellfish.[Conclusions]This study provides a theoretical basis for the detection of seafood animal-derived components.
文摘In view of the occurrence and aggravation of diseases and pests of horticultural crops,the management process should follow the basic policy of"prevention first,comprehensive control".Starting from the ecological system,agricultural,biological,physical and chemical means should be comprehensively applied to control diseases and pests below the economic injury level.
文摘With the rapid development of modern information technology, digital technology has gradually penetrated into all fields and links of the agricultural industry. Digital orchard reflects the comprehensive application of digital technology in orchard management. This study surveys and analyzes the current development of digital orchard, clarifies the development status and existing problems, and comes up with reasonable recommendations, to provide a certain reference and guidance for the construction of digital orchard in Zibo City of Shandong Province.
文摘[Objectives]The study aims to verify the application effect of silicon-containing water-soluble fertilizer on fast vegetables.[Methods]Two vegetable crops,rape and lettuce,were studied,and three treatments were set up,including treatment 1(conventional fertilization+foliar spraying of silicon-containing water-soluble fertilizer,treatment 2(conventional fertilization+foliar spraying of the same amount of clear water),and treatment 3(conventional fertilization).[Results]The yield of lettuce and rape in treatment 1 increased by 15.1%and 8.6%,respectively;compared with treatment 3,the yield of lettuce and rape rose by 18.6%and 10.9%,respectively.Variance analysis shows that the F values of lettuce and rape were 20.938 and 35.372,respectively,and the differences among various treatments were extremely significant.[Conclusions]The application of silicon-containing water-soluble fertilizer on lettuce and rape significantly increased their yield.
基金supported by the National Natrual Sciece Foundation of China (Nos. 21650110454, 21675164, 2 822407)the CAS-President International Fellowship Initiative (No. 2017PC0014)the Funds for Distinguished Young Scientists of Gansu (No. 1506RJDA281)
文摘Here we firstly report a series of new deep eutectic solvents(DESs) induced by small amounts of crown ether complex and mainly formed by polyethylene glycol. These DESs not only presented the ultra-deep extraction of non-basic N-compounds from fuel oils, but also opened up the possibility of other new applications in chemistry and materials science.
基金financial supports from the National Natural Science Foundation of China (Nos.21708017,21572093,21778028)Lanzhou University (the Fundamental Research Funds for the Central Universities,No.lzujbky-2018-64)Natural Science Foundation of Gansu Province (No.17JR5RA193)
文摘Cysteine(Cys)plays a pivotal role in many physiological and pathological processes,including detoxification and protein synthesis.The abnormal levels of Cys are linked to many diseases.In this study,a novel red-emitting off-on fluorescent probe Cys-TCF was masterly constructed for discriminative detection of Cys.After a series of experimental assessment,Cys-TCF displayed higher selectivity and sensitivity for Cys over other biothilols with a low detection limit(0.04μmol/L).More notably,the probe was also successfully applied to image Cys in live cells and live zebrafishes with low cytotoxicity.
基金Financial supports from the National Natural Science Foundation of China (Nos. 21822407 and 21675164)the funds for Distinguished Young Scientists of Gansu (No. 1506RJDA281) are gratefully acknowledged
文摘Porous graphene(PG) has potential applications in numerous fields because of the existence of nanopores in the plane. In this study, porous graphene decorated silica microspheres(Sil-PG) were successfully fabricated by assembling PG onto the silica particles surface in deep eutectic solvents(DESs).Experimental results demonstrate that this new stationary phase can facilitate the separation of six sulfonamides compounds in hydrophilic chromatographic conditions. The successful synthesis of the SilPG stationary phase provides a basis for the application of porous graphene-modified materials as the stationary phase for liquid chromatography, and offers the possibility to broaden the application of PG in the field of chromatography.
基金Project supported by the State Key Program of National Natural Science of China(No.11232009)the National Natural Science Foundation of China(Nos.11372171 and 11422214)
文摘The transverse vibration of an axially moving string supported by a viscoelastic foundation is analysed using the complex modal method. The equation of motion is developed using the generalized Hamilton principle. The exact closed-form solution of eigenvalues and eigen- functions are obtained. The governing equation is represented in a canonical state space form defined by two matrix differential operators, and the eigenfunctions and adjoint eigenfunctions are proved to be orthogonal with respect to each operator. This orthogonality is applied so that the response to arbitrary external excitations and initial conditions can be expressed in modal expansion. Numerical examples are presented to validate the proposed approach.
基金This work was supported by the NSFC(Grant 51861145101,21777096,22025505)Program of Shanghai Academic Technology Research Leader(Grant 20XD1422200)+1 种基金Cultivating fund of Frontiers Science Center for Transformative Molecules(2019PT02)China Postdoctoral Science Foundation(2020M671110).
文摘The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D structure,which can cause the ion migration and the related defects.Here,we found that the in situ-grown perovskitoid TEAPbI_(3)layer on 3D MAPbI_(3)can inhibit the MA^(+)migration in a polar solvent,thus enhancing the thermal and moisture stability of perovskite films.The crystal structure and orientation of TEAPbI_(3)are reported for the first time by single crystal and synchrotron radiation analysis.The ultra-thin perovskitoid layer can reduce the trap states and accelerate photo-carrier diffusion in perovskite solar cells,as confirmed by ultra-fast spectroscopy.The power conversion efficiency of TEAPbI_(3)-MAPbI_(3)based solar cells increases from 18.87%to 21.79%with enhanced stability.This work suggests that passivation and stabilization by in situ-grown perovskitoid can be a promising strategy for efficient and stable perovskite solar cells.
