Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usu...Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usually involves complex procedures and extremely depends on unidirectional freezing technique.Herein,we propose a groundbreaking approach that leverages the assemblies of salting-out protein induced by ammonium metatungstate(AM)as the precursor,and then acquire directional three-dimensional carbon-based foams through simple pyrolysis.The electrostatic interaction between AM and protein ensures well dispersion of WC_(1−x)nanoparticles on carbon frameworks.The content of WC_(1−x)nanoparticles can be rationally regulated by AM dosage,and it also affects the electromagnetic(EM)properties of final carbon-based foams.The optimized foam exhibits exceptional EM absorption performance,achieving a remarkable minimum reflection loss of−72.0 dB and an effective absorption bandwidth of 6.3 GHz when EM wave propagates parallel to the directional pores.Such performance benefits from the synergistic effects of macroporous architecture and compositional design.Although there is a directional dependence of EM absorption,radar stealth simulation demonstrates that these foams can still promise considerable reduction in radar cross section with the change of incident angle.Moreover,COMSOL simulation further identifies their good performance in preventing EM interference among different electronic components.展开更多
Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and ma...Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.展开更多
AIM: To examine the influences of personality characteristics and coping modes on the anxiety of primary glaucoma patients.METHODS: A total of 200 individuals, including 50 with primary angle-closure glaucoma, 60 with...AIM: To examine the influences of personality characteristics and coping modes on the anxiety of primary glaucoma patients.METHODS: A total of 200 individuals, including 50 with primary angle-closure glaucoma, 60 with primary open angle glaucoma and 90 control participants, filled out the State-Trait Anxiety Inventory, NEO Five-Factor Inventory, and Medical Coping Modes Questionnaire. Sociodemographic information was also collected. Data were analyzed via the Spearman rank correlation test and stepwise regression.RESULTS: The personality and coping variables are predictive and jointly account for a significant amount (45.3%-54.2%) of variance across the two subscales of anxiety measures. Notably, neuroticism seems to be most closely related to anxiety disturbances in glaucoma patients. The level of resignation is positively linked to anxiety scores.CONCLUSION: Some personality factors and coping modes help to predict the process of anxiety disorders in primary glaucoma patients. Recognizing the predictive role of these variables in the patients may further enrich clinical research in glaucoma and help to design more effective interventions involving both ophthalmology and psychiatry.展开更多
Phenolics,as the main bioactive compounds in tea,have been suggested to have potential in the prevention of various human diseases.However,little is known about phenolics and their bioactivity in Zhangping Narcissue t...Phenolics,as the main bioactive compounds in tea,have been suggested to have potential in the prevention of various human diseases.However,little is known about phenolics and their bioactivity in Zhangping Narcissue tea cake which is considered the most special kind of oolong tea.To unveil its bioactivity,three phenolic-enriched extracts were obtained from Zhangping Narcissue tea cake using ethyl acetate,n-butanol,and water.Their main chemical compositions and in vitro bioactivity were analyzed by high-performance liquid chromatography(HPLC)and ultraperformance liquid chromatography-mass spectrometry(UPLC-MS).The ethyl acetate fraction(ZEF)consisted of higher content of phenolics,flavonoids,procyanidins,and catechin monomers(including epigallocatechin gallate(EGCG),epicatechin gallate(ECG),and gallocatechin gallate(GCG))than n-butanol fraction(ZBF)and water fraction(ZWF).ZEF exhibited the strongest antioxidant capacity in vitro due to its abundant bioactive compounds.This was validated by Pearson correlation and hierarchical clustering analyses.ZEF also showed a remarkable inhibition on the growth,migration,and invasion of 4T1 murine breast cancer cells.展开更多
Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directl...Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.展开更多
Endotracheal intubation-related complications are common in clinical,and there are currently no effective strategies to address these matters.Inspired by the biological characteristics of human airway mucus(HAM),an ar...Endotracheal intubation-related complications are common in clinical,and there are currently no effective strategies to address these matters.Inspired by the biological characteristics of human airway mucus(HAM),an artificial airway mucus(ARM)coating is straightforwardly constructed by combining carboxymethyl chitosan with methyl cellulose.The ARM coating exhibited excellent lubricity(coefficient of friction(Co F)=0.05)and hydrophilicity(water contact angle(WCA)=21.3°),and was capable of coating both the internal and external surfaces of the endotracheal tube(ETT).In vitro experiments demonstrated that the ARM coating not only showed good broad-spectrum antibacterial activity,but also significantly reduced nonspecific protein adhesion.Through an in vivo intubation cynomolgus monkey model,ARM-coated ETT potently mitigated airway injury and inflammation,and was highly potential to prevent bacterial infection and catheter blockage.This work offers a promising avenue for the development of airway-friendly invasive devices.展开更多
Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting met...Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting metal parts remains a severe challenge for the applications.Here,a novel dual-additive synergy strategy is presented,which simultaneously enhances material removal efficiency and regulates electrode surface reactions during electrochemical polishing(ECP)of AM AlSi10Mg.Theoretical studies and experimental characterizations confirm that NaF promotes selective dissolution at the peaks,while glucose acts as a stabilizer for the surface valleys.This approach effectively facilitates the selective removal of surface protrusions,achieving a smoother and more uniform surface finish,resulting in a surface roughness reduction of approximately 86%,compared to a 63%reduction without additives.This study not only provides a new approach for optimizing surface quality of AM AlSi10Mg but also offers new insights into electrolyte design and the stabilization of metal anodes.展开更多
The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterost...The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.展开更多
Defects in crystals can have a profound impact on their electronic structure and physicochemical proper-ties.To address the limitations in photogenerated carrier mobility and to suppress the recombination of photogene...Defects in crystals can have a profound impact on their electronic structure and physicochemical proper-ties.To address the limitations in photogenerated carrier mobility and to suppress the recombination of photogenerated electrons and holes,defect engineering has been employed in the design of photocata-lysts.By creating appropriate defect energy levels or trap states,can be introduced into the photocatalyst.This modification alters the migration paths of photogenerated carriers,facilitating the rapid transfer of photogenerated charges to the catalyst surface for redox reactions.However,as a typical transition metal photocatalyst,cadmium sulfide(CdS)faces challenges related to photocorrosion,with poor photostability being a significant barrier to its large-scale production and utilization.In this study,we focus on three-dimensional CdS and CeO_(2) hollow spheres,regulating the vacancy contents in CdS and CeO_(2) under the guidance of a defect design strategy.This approach aims to construct a hollow core-shell heterojunction of H-CeO_(2)/H-CdS containing both sulfur and oxygen dual defects,thereby enhancing the photocatalytic activity and photostability of CdS-based composite materials.By employing a well-considered defect de-sign,the electronic structure of the catalyst can be modulated,extending the light absorption range into the visible-near-infrared region.Additionally,density functional theory(DFT)calculations were conducted to analyze the influence of sulfur and oxygen defects on the enhanced photocatalytic activity of the het-erojunction.The mechanism of the photocatalytic hydrogen evolution reaction with the heterojunction is summarized,providing insights into the improved performance of the material.展开更多
Frequency conversion is pivotal in nonlinear optics and quantum optics for manipulating and translating light signals across different wavelength regimes.Achieving frequency conversion between two light beams with a s...Frequency conversion is pivotal in nonlinear optics and quantum optics for manipulating and translating light signals across different wavelength regimes.Achieving frequency conversion between two light beams with a small frequency interval is a central challenge.In this work,we design a pair of coupled silicon microrings wherein coupled-induced modesplitting exists to achieve a small frequency shift by the process of four-wave mixing Bragg scattering.As an example,the signal can be up or down converted to the idler which is 15.5 GHz spaced when two pumps align with another pair of split resonances.The results unveil the potential of coupled microring resonators for small interval frequency conversion in a high-fidelity,all-optical,and signal processing quantum frequency interface.展开更多
Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lit...Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.展开更多
Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optim...Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22475057 and No.52373262).
文摘Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usually involves complex procedures and extremely depends on unidirectional freezing technique.Herein,we propose a groundbreaking approach that leverages the assemblies of salting-out protein induced by ammonium metatungstate(AM)as the precursor,and then acquire directional three-dimensional carbon-based foams through simple pyrolysis.The electrostatic interaction between AM and protein ensures well dispersion of WC_(1−x)nanoparticles on carbon frameworks.The content of WC_(1−x)nanoparticles can be rationally regulated by AM dosage,and it also affects the electromagnetic(EM)properties of final carbon-based foams.The optimized foam exhibits exceptional EM absorption performance,achieving a remarkable minimum reflection loss of−72.0 dB and an effective absorption bandwidth of 6.3 GHz when EM wave propagates parallel to the directional pores.Such performance benefits from the synergistic effects of macroporous architecture and compositional design.Although there is a directional dependence of EM absorption,radar stealth simulation demonstrates that these foams can still promise considerable reduction in radar cross section with the change of incident angle.Moreover,COMSOL simulation further identifies their good performance in preventing EM interference among different electronic components.
基金supported by the “Climbing Plan” of Harbin Normal University (No.XKB202301)National Natural Science Foundation of China (Nos.21871065 and 22071038)。
文摘Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.
基金Supported by the National Natural Science Foundation of China(No.81870634)
文摘AIM: To examine the influences of personality characteristics and coping modes on the anxiety of primary glaucoma patients.METHODS: A total of 200 individuals, including 50 with primary angle-closure glaucoma, 60 with primary open angle glaucoma and 90 control participants, filled out the State-Trait Anxiety Inventory, NEO Five-Factor Inventory, and Medical Coping Modes Questionnaire. Sociodemographic information was also collected. Data were analyzed via the Spearman rank correlation test and stepwise regression.RESULTS: The personality and coping variables are predictive and jointly account for a significant amount (45.3%-54.2%) of variance across the two subscales of anxiety measures. Notably, neuroticism seems to be most closely related to anxiety disturbances in glaucoma patients. The level of resignation is positively linked to anxiety scores.CONCLUSION: Some personality factors and coping modes help to predict the process of anxiety disorders in primary glaucoma patients. Recognizing the predictive role of these variables in the patients may further enrich clinical research in glaucoma and help to design more effective interventions involving both ophthalmology and psychiatry.
基金Project supported by the Science and Technology Department of Guangdong Province,China(No.2016B090918118)
文摘Phenolics,as the main bioactive compounds in tea,have been suggested to have potential in the prevention of various human diseases.However,little is known about phenolics and their bioactivity in Zhangping Narcissue tea cake which is considered the most special kind of oolong tea.To unveil its bioactivity,three phenolic-enriched extracts were obtained from Zhangping Narcissue tea cake using ethyl acetate,n-butanol,and water.Their main chemical compositions and in vitro bioactivity were analyzed by high-performance liquid chromatography(HPLC)and ultraperformance liquid chromatography-mass spectrometry(UPLC-MS).The ethyl acetate fraction(ZEF)consisted of higher content of phenolics,flavonoids,procyanidins,and catechin monomers(including epigallocatechin gallate(EGCG),epicatechin gallate(ECG),and gallocatechin gallate(GCG))than n-butanol fraction(ZBF)and water fraction(ZWF).ZEF exhibited the strongest antioxidant capacity in vitro due to its abundant bioactive compounds.This was validated by Pearson correlation and hierarchical clustering analyses.ZEF also showed a remarkable inhibition on the growth,migration,and invasion of 4T1 murine breast cancer cells.
基金financially supported by the financial support from Natural Science Foundation of China(No.22209129)the High-Level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.QCYRCXM-2022-123)+3 种基金the Innovation Capability Support Program of Shaanxi(No.2023-CXTD-26)the financial support from the"Young Talent Support Plan''of Xi'an Jiaotong University(No.HG6J024)the financial support from China Postdoctoral Science Foundation 2024M752560Postdoctoral Fellowship Program of CPSF under Grant Number GZB20230574
文摘Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.
基金supported by the National Natural Science Foundation of China(Nos.52203046 and 82171219)Sichuan Science and Technology Program(No.2023NSFSC1944)+3 种基金West China Nursing Discipline Development Special Fund ProjectSichuan University(No.HXHL21007)the China Postdoctoral Science Foundation(No.2023M742483)the National Natural Science Foundation of Guangdong(No.2024A1515012881)。
文摘Endotracheal intubation-related complications are common in clinical,and there are currently no effective strategies to address these matters.Inspired by the biological characteristics of human airway mucus(HAM),an artificial airway mucus(ARM)coating is straightforwardly constructed by combining carboxymethyl chitosan with methyl cellulose.The ARM coating exhibited excellent lubricity(coefficient of friction(Co F)=0.05)and hydrophilicity(water contact angle(WCA)=21.3°),and was capable of coating both the internal and external surfaces of the endotracheal tube(ETT).In vitro experiments demonstrated that the ARM coating not only showed good broad-spectrum antibacterial activity,but also significantly reduced nonspecific protein adhesion.Through an in vivo intubation cynomolgus monkey model,ARM-coated ETT potently mitigated airway injury and inflammation,and was highly potential to prevent bacterial infection and catheter blockage.This work offers a promising avenue for the development of airway-friendly invasive devices.
基金financially supported by the National Natural Science Foundation of China(Nos.52175444,51905506,21871065 and 22071038)the Sichuan Science and Technology Program(No.2021JDJQ0014).
文摘Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting metal parts remains a severe challenge for the applications.Here,a novel dual-additive synergy strategy is presented,which simultaneously enhances material removal efficiency and regulates electrode surface reactions during electrochemical polishing(ECP)of AM AlSi10Mg.Theoretical studies and experimental characterizations confirm that NaF promotes selective dissolution at the peaks,while glucose acts as a stabilizer for the surface valleys.This approach effectively facilitates the selective removal of surface protrusions,achieving a smoother and more uniform surface finish,resulting in a surface roughness reduction of approximately 86%,compared to a 63%reduction without additives.This study not only provides a new approach for optimizing surface quality of AM AlSi10Mg but also offers new insights into electrolyte design and the stabilization of metal anodes.
基金supported by the National Natural Science Foundation of China(No.22369025)Yunnan Applied Basic Research Projects(Nos.202201AT070095,202301AT070098,202301AT070107,202401AT070438,and 202401AT070433)+2 种基金Education Reform Research Project of Yunnan University(No.2021Z06)Yunnan University Graduate Student Practice and Innovation Program(Nos.ZC-23234269,ZC-23235291,KC-23236398,and KC-23234063)Yunnan Revitalization Talent Support Program。
文摘The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.
基金financially supported by the National Natural Science Foundation of China(Nos.21871065 and 22071038)the Heilongjiang Touyan Team(No.HITTY-20190033)+1 种基金the Interdisci-plinary Research Foundation of HIT(No.IR2021205)the China Postdoctoral Foundation(No.GZC20241809).
文摘Defects in crystals can have a profound impact on their electronic structure and physicochemical proper-ties.To address the limitations in photogenerated carrier mobility and to suppress the recombination of photogenerated electrons and holes,defect engineering has been employed in the design of photocata-lysts.By creating appropriate defect energy levels or trap states,can be introduced into the photocatalyst.This modification alters the migration paths of photogenerated carriers,facilitating the rapid transfer of photogenerated charges to the catalyst surface for redox reactions.However,as a typical transition metal photocatalyst,cadmium sulfide(CdS)faces challenges related to photocorrosion,with poor photostability being a significant barrier to its large-scale production and utilization.In this study,we focus on three-dimensional CdS and CeO_(2) hollow spheres,regulating the vacancy contents in CdS and CeO_(2) under the guidance of a defect design strategy.This approach aims to construct a hollow core-shell heterojunction of H-CeO_(2)/H-CdS containing both sulfur and oxygen dual defects,thereby enhancing the photocatalytic activity and photostability of CdS-based composite materials.By employing a well-considered defect de-sign,the electronic structure of the catalyst can be modulated,extending the light absorption range into the visible-near-infrared region.Additionally,density functional theory(DFT)calculations were conducted to analyze the influence of sulfur and oxygen defects on the enhanced photocatalytic activity of the het-erojunction.The mechanism of the photocatalytic hydrogen evolution reaction with the heterojunction is summarized,providing insights into the improved performance of the material.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFF0712800)。
文摘Frequency conversion is pivotal in nonlinear optics and quantum optics for manipulating and translating light signals across different wavelength regimes.Achieving frequency conversion between two light beams with a small frequency interval is a central challenge.In this work,we design a pair of coupled silicon microrings wherein coupled-induced modesplitting exists to achieve a small frequency shift by the process of four-wave mixing Bragg scattering.As an example,the signal can be up or down converted to the idler which is 15.5 GHz spaced when two pumps align with another pair of split resonances.The results unveil the potential of coupled microring resonators for small interval frequency conversion in a high-fidelity,all-optical,and signal processing quantum frequency interface.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0712800 and 2019YFA0308700)。
文摘Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301500)the National Natural Science Foundation of China(Grant No.62105366)。
文摘Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.
