Education on cultural confidence is the main way to strengthen one's cultural confidence while cultural consciousness constitutes a base for cultural confidence.The two would be unified in the process of strengthe...Education on cultural confidence is the main way to strengthen one's cultural confidence while cultural consciousness constitutes a base for cultural confidence.The two would be unified in the process of strengthening cultural confidence.Therefore,there is a logical relationship between them.In order to understand the relationship between education on cultural confidence and cultural consciousness,one needs to have a correct understanding of the scientific connotation of the two and a clear picture that education on cultural confidence would ensure that one would be kept steadfast in cultural consciousness because it does not only establish attitudes in cultural conscious cognition but also act as a guide for internal development.展开更多
High-light(HL)stress is a major environmental factor that limits crop productivity.Maize(Zea mays)and rice(Oryza sativa),two key global crops,can both grow under HL intensities but differ in photosynthetic metabolism;...High-light(HL)stress is a major environmental factor that limits crop productivity.Maize(Zea mays)and rice(Oryza sativa),two key global crops,can both grow under HL intensities but differ in photosynthetic metabolism;maize is a C4 species,whereas rice is a C3 species.However,the molecular mechanisms un-derlying their responses to HL stress remain poorly understood.To systematically dissect how HL affects maize and rice growth,we conducted time-resolved multi-omics analyses,examining the transcriptome,translatome,proteome,and metabolome in response to HL treatment.Integration of this multiomics approach with physiological analyses revealed that rice exhibits a more rapid response to HL stress than maize,with significant alterations in photosynthetic electron transport,energy dissipation,reactive oxygen species(ROS)accumulation,and primary metabolism.In contrast,the higher tolerance of maize to HL stress is primarily attributed to increased cyclic electron flow(CEF)and non-photochemical quench-ing(NPQ),elevated sugar and aromatic amino acid accumulation,and enhanced antioxidant activity during 4 h of HL exposure.Transgenic experiments further validated key regulators of HL tolerance;for instance,knockout of OsbZIP18 enhanced HL tolerance in rice,whereas overexpression of ZmPsbS in maize signif-icantly boosted photosynthesis and energy-dependent quenching(qE)after 4 h of HL treatment,underscoring its role in protecting C4 crops from HL-induced photodamage.Taken together,these findings provide new insights into the molecular mechanisms of HL stress tolerance in C4 versus C3 species and highlight a set of candidate genes for engineering improved HL tolerance in crops.展开更多
Impedance analysis is an effective method to analyze the oscillation issue associated with grid-connected photovoltaic systems.However,the existing impedance modeling of a gridconnected photovoltaic inverter usually o...Impedance analysis is an effective method to analyze the oscillation issue associated with grid-connected photovoltaic systems.However,the existing impedance modeling of a gridconnected photovoltaic inverter usually only considers the effect of a single perturbation frequency,ignoring the coupling frequency response between the internal control loops of a grid-connected inverter,which severely affects the accuracy of the stability analysis.Hence,a method of impedance modeling and stability analysis for grid-connected photovoltaic inverters considering cross-coupling frequency is proposed in this paper.First,the generation mechanism of frequency coupling in gridconnected photovoltaic inverters,and the relationship between the coupling frequency and perturbation frequency are analyzed.Secondly,a sequence impedance model of grid-connected photovoltaic systems considering the coupling frequency is established by using the harmonic linearization method.The impact of DC bus voltage control strategy on frequency coupling characteristics of a grid-connected photovoltaic system is evaluated,and the impact of a coupling frequency term on system stability is quantitatively analyzed.Finally,the advantages of the proposed method are verified by several simulations.The results show that the proposed impedance model can accurately predict the potential resonance points of the system,and the coupling frequency characteristics will become much stronger with smaller DC bus capacitance or larger bandwidth of the DC bus controller.展开更多
A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical pro...A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells(IT-SOFCs).The corresponding thermochemical stability,thermal expansion behavior,electrical conductivity and cathodic polarization resistance of the materials were systematically investigated.It was found that the A-site dual lanthanide doped Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5+σ)(PGBCO)exhibits improved electrical conductivity,reduced thermal expansion,and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite,PrBaCo_(2)O_(5+σ)(PBCO)and GdBaCo_(2)O_(5+σ)(GBCO)materials.Further investigation on the effect of B-site Fe-doping on Pr_(0.5)Gd_(0.5)BaCo_(2)-yFeyO_(5)+σ(PGBCF-y,0≤y≤1)reveals that all the PGBCF-y compositions exhibit excellent chemical stability with Gd-doped ceria(GDC)at operating temperatures not higher than 1100℃.Besides,doping of Fe in B-site can effectively reduce the thermal expansion coefficients(TECs)of the Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5)+σceramics at 30e1000℃.And the electrochemical impedance spectra(EIS)results show that the PGBCF-y|GDC|PGBCF-y symmetric cells have acceptable low area specific polarization resistances.Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution(DRT)method demonstrated that charge transfer is the dominating subprocess for the oxygen transport through the materials.展开更多
文摘Education on cultural confidence is the main way to strengthen one's cultural confidence while cultural consciousness constitutes a base for cultural confidence.The two would be unified in the process of strengthening cultural confidence.Therefore,there is a logical relationship between them.In order to understand the relationship between education on cultural confidence and cultural consciousness,one needs to have a correct understanding of the scientific connotation of the two and a clear picture that education on cultural confidence would ensure that one would be kept steadfast in cultural consciousness because it does not only establish attitudes in cultural conscious cognition but also act as a guide for internal development.
基金supported by grants from the Key Program of the National Natural Science Foundation of China(32330079)Nanfan Special Project,CAAS(YBXM2321)+3 种基金the General Program of the National Natural Science Foundation of China(32372027,32472040,and 32170409)the Innovation Program of the Chinese Academy of Agricultural Sciencesthe National Key Research and Development Program of China(2023YFE0109500)the Biological Breeding-National Science and Technology Major Project(2023ZD04072).
文摘High-light(HL)stress is a major environmental factor that limits crop productivity.Maize(Zea mays)and rice(Oryza sativa),two key global crops,can both grow under HL intensities but differ in photosynthetic metabolism;maize is a C4 species,whereas rice is a C3 species.However,the molecular mechanisms un-derlying their responses to HL stress remain poorly understood.To systematically dissect how HL affects maize and rice growth,we conducted time-resolved multi-omics analyses,examining the transcriptome,translatome,proteome,and metabolome in response to HL treatment.Integration of this multiomics approach with physiological analyses revealed that rice exhibits a more rapid response to HL stress than maize,with significant alterations in photosynthetic electron transport,energy dissipation,reactive oxygen species(ROS)accumulation,and primary metabolism.In contrast,the higher tolerance of maize to HL stress is primarily attributed to increased cyclic electron flow(CEF)and non-photochemical quench-ing(NPQ),elevated sugar and aromatic amino acid accumulation,and enhanced antioxidant activity during 4 h of HL exposure.Transgenic experiments further validated key regulators of HL tolerance;for instance,knockout of OsbZIP18 enhanced HL tolerance in rice,whereas overexpression of ZmPsbS in maize signif-icantly boosted photosynthesis and energy-dependent quenching(qE)after 4 h of HL treatment,underscoring its role in protecting C4 crops from HL-induced photodamage.Taken together,these findings provide new insights into the molecular mechanisms of HL stress tolerance in C4 versus C3 species and highlight a set of candidate genes for engineering improved HL tolerance in crops.
文摘Impedance analysis is an effective method to analyze the oscillation issue associated with grid-connected photovoltaic systems.However,the existing impedance modeling of a gridconnected photovoltaic inverter usually only considers the effect of a single perturbation frequency,ignoring the coupling frequency response between the internal control loops of a grid-connected inverter,which severely affects the accuracy of the stability analysis.Hence,a method of impedance modeling and stability analysis for grid-connected photovoltaic inverters considering cross-coupling frequency is proposed in this paper.First,the generation mechanism of frequency coupling in gridconnected photovoltaic inverters,and the relationship between the coupling frequency and perturbation frequency are analyzed.Secondly,a sequence impedance model of grid-connected photovoltaic systems considering the coupling frequency is established by using the harmonic linearization method.The impact of DC bus voltage control strategy on frequency coupling characteristics of a grid-connected photovoltaic system is evaluated,and the impact of a coupling frequency term on system stability is quantitatively analyzed.Finally,the advantages of the proposed method are verified by several simulations.The results show that the proposed impedance model can accurately predict the potential resonance points of the system,and the coupling frequency characteristics will become much stronger with smaller DC bus capacitance or larger bandwidth of the DC bus controller.
基金supported by the National Natural Science Foundation of China(Grant No.52062002 and 51961006)the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University,China(2021GXYSOF01).
文摘A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells(IT-SOFCs).The corresponding thermochemical stability,thermal expansion behavior,electrical conductivity and cathodic polarization resistance of the materials were systematically investigated.It was found that the A-site dual lanthanide doped Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5+σ)(PGBCO)exhibits improved electrical conductivity,reduced thermal expansion,and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite,PrBaCo_(2)O_(5+σ)(PBCO)and GdBaCo_(2)O_(5+σ)(GBCO)materials.Further investigation on the effect of B-site Fe-doping on Pr_(0.5)Gd_(0.5)BaCo_(2)-yFeyO_(5)+σ(PGBCF-y,0≤y≤1)reveals that all the PGBCF-y compositions exhibit excellent chemical stability with Gd-doped ceria(GDC)at operating temperatures not higher than 1100℃.Besides,doping of Fe in B-site can effectively reduce the thermal expansion coefficients(TECs)of the Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5)+σceramics at 30e1000℃.And the electrochemical impedance spectra(EIS)results show that the PGBCF-y|GDC|PGBCF-y symmetric cells have acceptable low area specific polarization resistances.Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution(DRT)method demonstrated that charge transfer is the dominating subprocess for the oxygen transport through the materials.
