Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted...Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted widespread attention.Herein,Co-based metal-organic framework(Co(bpdc)(H_(2)O)_(4)(CoMOF)nanosheets as passivation layers were in-situ constructed on the surface of Bi VO_(4)films through an uncomplicated hydrothermal method(Co-MOF/Bi VO_(4)).Under AM 1.5G illumination,synthesized CoMOF/BiVO_(4)electrode exhibited a 4-fold higher photocurrent than bare Bi VO_(4),measuring 6.0 m A/cm^(2)at 1.23 V vs.RHE in 1 mol/L potassium borate electrolyte(pH 9.5)solution.Moreover,the Co-MOF/BiVO_(4)film demonstrated a 96%charge separation efficiency,a result caused by an inhibited recombination rate of photogenerated electrons and holes by the addition of Co-MOF nanosheets.This work provides an idea for depositing inexpensive 2D Co-MOF nanosheets on the photoanode as an excellent passivation layer for solar fuel production.展开更多
Low earth orbit satellites,with unique advantages,are prosperous types of navigation augmentation satellites for the GNSS satellites constellations.The broadcast ephemeris element needs to be designed as an important ...Low earth orbit satellites,with unique advantages,are prosperous types of navigation augmentation satellites for the GNSS satellites constellations.The broadcast ephemeris element needs to be designed as an important index of the augmented LEOs.The GPS ephemerides of 16/18 elements cannot be directly applied to the LEOs because of the poor fitting accuracies in along-track positional component.Besides,the ill-conditioned problem of the normal-matrix exists in fitting algorithm due to the small eccentricity of the LEO orbits.Based on the nonsingular orbital elements,5 sets of ephemerides with element numbers from 16 to 19 were designed respectively by adding or modifying orbital elements magnifying the along-track and radial positional components.The fitting experiments based on the LEO of 300 to 1500 km altitudes show that the fitting UREs of the proposed 16/17/18/18*/19-element ephemerides are better than 10/6/4/5/2.5 cm,respectively.According to the dynamical range of the fitting elements,the interfaces were designed for the 5 sets of ephemerides.The effects of data truncation on fitting UREs are at millimeter level.The total bits are 329/343/376/379/396,respectively.29/15 bits are saved for the 16/17-element ephemerides compared with the GPS16 ephemeris,while 64/61/41 bits can be saved for the 18/18*/19-element ephemerides compared with the GPS18 elements ephemeris.展开更多
The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new ser...The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new series of positively charged hollow microspheres carrying porphyrin moieties.Such hollow spheres are formed through crosslinking of well-ordered porous thin laminates,initiated by co-assembly of regular monomers and those decorated with porphyrin moieties.On the surface of an individual sphere,densely distributed positive sites attract anionic reactants.The superficial porphyrin decomposes the accumulated reactants under 1 Sun.After degradation and release of products,the photoactive sites are thereby renewed.We demonstrate that polymer network(1:10)exhibited superior sustainable photocatalytic performance with complete degradation of methyl orange(MO)in 40 min with no observable performance deterioration after six cycles.The established close loop of adsorption-reaction-release cycle makes possible many efficient and continuous photo-catalytic processes.展开更多
Previous research has suggested that familiarity can enhance associative memory after unitization,but the cognitive mechanisms underlying unitization remain debated.To explore the neural mechanisms of associative memo...Previous research has suggested that familiarity can enhance associative memory after unitization,but the cognitive mechanisms underlying unitization remain debated.To explore the neural mechanisms of associative memory after unitization in the absence of semantic relations,we used Chinese characters as stimuli and recorded participants’blood oxygen level-dependent signals during recognition.Behavioral results showed that after Chinese character unitization,not only the associative performance of recognition(Pr,hit rate minus false alarm rate)and general Pr but also the hit rate and correct rejection rate increased.Neuroimaging results revealed activation of the hippocampus and parahippocampal gyrus during associative recognition in both the unitized and the non-unitized condition,and hippocampal activation increased after unitization.However,activation of the perirhinal cortex was not observed in either condition.These findings,in contrast to those from previous studies on unitization,suggest that Chinese character unitization enhances recollection-based,rather than familiarity-based,associative recognition.This suggests that the encoding of semantic relations during unitization is critical for subsequent familiarity-based associative recognition.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52173277)the Innovative Research Team for Science and Technology of Shaanxi Province(No.2022TD-04)+1 种基金the Fundamental Research Funds for the Central Universities of Chang’an University(Nos.300102299304,300102291403)the Natural Science Basic Research Fund of Shaanxi Province(No.2020JZ-20)。
文摘Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted widespread attention.Herein,Co-based metal-organic framework(Co(bpdc)(H_(2)O)_(4)(CoMOF)nanosheets as passivation layers were in-situ constructed on the surface of Bi VO_(4)films through an uncomplicated hydrothermal method(Co-MOF/Bi VO_(4)).Under AM 1.5G illumination,synthesized CoMOF/BiVO_(4)electrode exhibited a 4-fold higher photocurrent than bare Bi VO_(4),measuring 6.0 m A/cm^(2)at 1.23 V vs.RHE in 1 mol/L potassium borate electrolyte(pH 9.5)solution.Moreover,the Co-MOF/BiVO_(4)film demonstrated a 96%charge separation efficiency,a result caused by an inhibited recombination rate of photogenerated electrons and holes by the addition of Co-MOF nanosheets.This work provides an idea for depositing inexpensive 2D Co-MOF nanosheets on the photoanode as an excellent passivation layer for solar fuel production.
文摘Low earth orbit satellites,with unique advantages,are prosperous types of navigation augmentation satellites for the GNSS satellites constellations.The broadcast ephemeris element needs to be designed as an important index of the augmented LEOs.The GPS ephemerides of 16/18 elements cannot be directly applied to the LEOs because of the poor fitting accuracies in along-track positional component.Besides,the ill-conditioned problem of the normal-matrix exists in fitting algorithm due to the small eccentricity of the LEO orbits.Based on the nonsingular orbital elements,5 sets of ephemerides with element numbers from 16 to 19 were designed respectively by adding or modifying orbital elements magnifying the along-track and radial positional components.The fitting experiments based on the LEO of 300 to 1500 km altitudes show that the fitting UREs of the proposed 16/17/18/18*/19-element ephemerides are better than 10/6/4/5/2.5 cm,respectively.According to the dynamical range of the fitting elements,the interfaces were designed for the 5 sets of ephemerides.The effects of data truncation on fitting UREs are at millimeter level.The total bits are 329/343/376/379/396,respectively.29/15 bits are saved for the 16/17-element ephemerides compared with the GPS16 ephemeris,while 64/61/41 bits can be saved for the 18/18*/19-element ephemerides compared with the GPS18 elements ephemeris.
基金supported by the National Natural Science Foundation of China(Nos.22172045,U23A20122,21905076,21905077)the Key Science Foundation Project of Henan Province(No.232300421146)the Key Scientific Research Project of Colleges and Universities in Henan Province(No.22B150001).
文摘The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new series of positively charged hollow microspheres carrying porphyrin moieties.Such hollow spheres are formed through crosslinking of well-ordered porous thin laminates,initiated by co-assembly of regular monomers and those decorated with porphyrin moieties.On the surface of an individual sphere,densely distributed positive sites attract anionic reactants.The superficial porphyrin decomposes the accumulated reactants under 1 Sun.After degradation and release of products,the photoactive sites are thereby renewed.We demonstrate that polymer network(1:10)exhibited superior sustainable photocatalytic performance with complete degradation of methyl orange(MO)in 40 min with no observable performance deterioration after six cycles.The established close loop of adsorption-reaction-release cycle makes possible many efficient and continuous photo-catalytic processes.
基金The National Natural Science Foundation of China,Grant/Award Number:31971030the Youth Beijing Scholar Project+1 种基金the Support Project of High-level Teachers in Beijing Municipal Universities in the Period of the 13th Five-year Planthe Capacity Building for Sci-Tech Innovation Fundamental Scientific Research Funds。
文摘Previous research has suggested that familiarity can enhance associative memory after unitization,but the cognitive mechanisms underlying unitization remain debated.To explore the neural mechanisms of associative memory after unitization in the absence of semantic relations,we used Chinese characters as stimuli and recorded participants’blood oxygen level-dependent signals during recognition.Behavioral results showed that after Chinese character unitization,not only the associative performance of recognition(Pr,hit rate minus false alarm rate)and general Pr but also the hit rate and correct rejection rate increased.Neuroimaging results revealed activation of the hippocampus and parahippocampal gyrus during associative recognition in both the unitized and the non-unitized condition,and hippocampal activation increased after unitization.However,activation of the perirhinal cortex was not observed in either condition.These findings,in contrast to those from previous studies on unitization,suggest that Chinese character unitization enhances recollection-based,rather than familiarity-based,associative recognition.This suggests that the encoding of semantic relations during unitization is critical for subsequent familiarity-based associative recognition.
