Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showin...Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showing a high activity in the catalytic oxidation of HCl to Cl_(2).The results on some extensive characterizations of both Ce-doped TiO_(2)carriers and their supported RuO_(2)catalysts show that the doping of Ce into TiO_(2)can effectively change the lattice parameters of TiO_(2)to improve the dispersion of the active RuO_(2)species on the carrier,which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions.This work provides some scientific basis and technical support for chlorine recycling.展开更多
Three large π-conjugated and imine-based COFs,named TFP-TAB,TFP-TTA,and TTA-TTB,were synthesized via the ordered incorporation of benzene and triazine rings in the same host framework to study how the structural unit...Three large π-conjugated and imine-based COFs,named TFP-TAB,TFP-TTA,and TTA-TTB,were synthesized via the ordered incorporation of benzene and triazine rings in the same host framework to study how the structural units affect the efficiency of CO_(2)photoreduction.Results from both experiments and density-functional theory(DFT)calculations indicate the separation and transfer of the photoinduced charges is highly related to the triazine-N content and the conjugation degree in the skeletons of COFs.High-efficiency CO_(2)photoreduction can be achieved by rationally adjusting the number and position of both benzene and triazine rings in the COFs.Specifically,TTA-TTB,with orderly interlaced triazine-benzene heterojunctions,can suppress the recombination probability of electrons and holes,which effectively immobilizes the key species(COOH)and lowers the free energy change of the potential-determining step,and thus exhibits a superior visible-light-induced photocatalytic activity that yields 121.7 μmol HCOOH g^(-1)h^(-1).This research,therefore,helps to elucidate the effects of the different structural blocks in COFs on inherent heterogeneous photocatalysis for CO_(2)reduction at a molecular level.展开更多
Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solu...Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.展开更多
Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed ga...Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed gas sensing system basedon optical frequency comb (OFC) calibrated frequency-modulated continuous-wave (FMCW) tuning nonlinearity. Thesystem can be used for multi-parameter synchronous measurement of gas absorption spectrum and multiplexed opticalpath. Multi-channel parallel detection is realized by combining wavelength division multiplexing (WDM) and frequencydivision multiplexing (FDM) techniques. By introducing nonlinear optical crystals, broadband spectrum detection is simultaneouslyachieved over a bandwidth of hundreds of nanometers. An OFC with ultra-high frequency stability is used asthe frequency calibration source, which guarantees the measurement accuracy. The test samples involve H13C14N, C_(2)H_(2)and Rb vapor cells of varying densities and 5 parallel measurement experiments are designed. The results show that themeasurement accuracies of spectral absorption line and the optical path are 150 MHz and 20 m, respectively. The schemeoffers the advantages of multiplexed, multi-parameter, wide spectrum and high resolution detection, which can realize theidentification of multi-gas components and the high-precision inversion of absorption lines under different environments.The proposed sensor demonstrates great potential in the field of high-resolution absorption spectrum measurement for gassensing applications.展开更多
In a polluted environment, considering the biological population infected with a kind of disease and hunted by human beings, we formulate a nonautonomous SIR population-epidemic model with time-varying impulsive relea...In a polluted environment, considering the biological population infected with a kind of disease and hunted by human beings, we formulate a nonautonomous SIR population-epidemic model with time-varying impulsive release and general nonlinear incidence rate and investigate dynamical behaviors of the model. Under the reasonable assumptions, the sufficient conditions which guarantee the globally attractive of the disease-free periodic solution and the permanence of the infected fish are established, that is, the infected fish dies out if , whereas the disease persists if . To substantiate our theoretical results, extensive numerical simulations are performed for a hypothetical set of parameter values.展开更多
Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to pro...Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to produce effective and efficient photocatalysts for CO_(2)reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO_(2)reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO_(2)reduction performance in order to achieve a long-term sustainability. Metalorganic frameworks(MOFs) are recently emerging as a new type of photocatalysts for CO_(2)reduction due to their excellent CO_(2)adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO_(2)reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO_(2)reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers,and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles(NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO_(2)reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO_(2)conversion.展开更多
The reduction of CO_(2)into high value-added chemicals and fuels by a photocatalytic technology can relieve energy shortages and the environmental problems caused by greenhouse effects.In the current work,an amino-fun...The reduction of CO_(2)into high value-added chemicals and fuels by a photocatalytic technology can relieve energy shortages and the environmental problems caused by greenhouse effects.In the current work,an amino-functionalized zirconium metal organic framework(Zr-MOF)was covalently modified with different functional groups via the condensation of Zr-MOF with 2-pyridinecarboxaldehyde(PA),salicylaldehyde(SA),benzaldehyde(BA),and trifluoroacetic acid(TA),named Zr-MOF-X(X=PA,SA,BA,and TA),respectively,through the post-synthesis modification.Compared with Zr-MOF and Zr-MOF-TA,the introduction of PA,SA,or BA into the framework of Zr-MOF can not only enhance the visible-light harvesting and CO_(2)capture,but also accelerate the photogenerated charge separation and transfer,thereby improving the photocatalytic ability of Zr-MOF for CO_(2)reduction.These results indicate that the modification of Zr-MOF with electron-donating groups can promote the photocatalytic CO_(2)reduction.Therefore,the current work provides an instructive approach to improve the photocatalytic efficiency of CO_(2)reduction through the covalent modification of MOFs.展开更多
This paper proposes a vector-borne plant disease model with discontinuous treatment strategies. Constructing Lyapunov function and applying non-smooth theory to analyze discontinuous differential equations, the basic ...This paper proposes a vector-borne plant disease model with discontinuous treatment strategies. Constructing Lyapunov function and applying non-smooth theory to analyze discontinuous differential equations, the basic reproductive number R0 is proved, which determines whether the plant disease will be extinct or not. If R0 R0 > 1 , there exists a unique endemic equilibrium which is globally stable. The numerical simulations are provided to verify our theoretical results, which indicate that after infective individuals reach some level, strengthening treatment measures is proved to be beneficial in controlling disease transmission.展开更多
In this paper, a Schistosomiasis japonicum model incorporating time delay is proposed which represents the developmental time from cercaria penetration through skins of human hosts to egg laying. By linearizing the sy...In this paper, a Schistosomiasis japonicum model incorporating time delay is proposed which represents the developmental time from cercaria penetration through skins of human hosts to egg laying. By linearizing the system at the positive equilibrium and analyzing the associated characteristic equations, the local stability of the equilibria is investigated. And it proves that Hopf bifurcations occur when the time delay passes through a sequence of critical value. Furthermore, the explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions are derived by using techniques from the normal form theory and Center Manifold Theorem. Some numerical simulations which support our theoretical analysis are also conducted.展开更多
Accurately perceiving the multidimensional geometric information of complex equipment is crucial for improving product quality and production efficiency.We propose a multichannel time-domain wavelength division multip...Accurately perceiving the multidimensional geometric information of complex equipment is crucial for improving product quality and production efficiency.We propose a multichannel time-domain wavelength division multiplexing frequency modulated continuous wave(FMCW)LiDAR integrated with the optical switch system scheme.This enables the implementation of time-domain wavelength division multiplexing technology for FMCW lasers,achieving the unified transmission of multi-length information through a single optical fiber channel.This system scheme enables parallel measurement of multiple targets and enhances the measurement accuracy of single targets by measuring the mean through multichannels,featuring versatility.In experiment,we achieved an overall absolute distance measurement accuracy better than 14μm and individual channel accuracy better than 20μm for non-cooperative targets at a distance of 1.3 m.The overall measurement standard deviation reached 14.73μm,and the minimum Allan deviation was 189 nm at a 2.84 s averaging time.Additionally,we demonstrated 3D imaging experiments with“TIF”patterned cardboard and corridor stairs,obtained data precision better than 0.8 cm,and achieved high reliability in 3D imaging.展开更多
In this paper,an all-optical tuning scheme of a multi-walled carbon nanotube(MWCNT)-coated microcavity is introduced,achieving high-speed precise resonance control across the free spectral range(FSR).A modulation lase...In this paper,an all-optical tuning scheme of a multi-walled carbon nanotube(MWCNT)-coated microcavity is introduced,achieving high-speed precise resonance control across the free spectral range(FSR).A modulation laser input through the microcavity tail fiber adjusts the resonance peak position,achieving a tuning efficiency of 107.3 pm/mW below 15 mW,with a maximum range exceeding one FSR and a response time of~20 ms.Combined with a fixed-wavelength pump,this scheme can precisely control the microcomb states.The scheme offers high tuning efficiency,simple fabrication,and low cost,making it suitable for applications in microcomb control and optical filters.展开更多
In this research,we report a two-dimensional pose measurement scheme based on a metasurface array reflector,which enables absolute tracking of both linear and angular positions.The metasurface array reflector,utilizin...In this research,we report a two-dimensional pose measurement scheme based on a metasurface array reflector,which enables absolute tracking of both linear and angular positions.The metasurface array reflector,utilizing the tailored optical field characteristics of a plasmonic absorption structure,simultaneously responds to linear and angular displacements within the illuminated optical field range and provides a characteristic absolute code to the receiving end.This code can be used to map the target's linear and angular position.By matching it with a pre-established template network,it is possible to track the target's absolute position.Under μm-level linear displacements and μrad-level angular displacements,we achieved precise two-dimensional linear and angular tracking and positioning based on this device.展开更多
The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Noneth...The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Nonetheless,due to the periodicity of its pulse train,the comb suffers from measurement dead zones and ambiguities,thereby impeding its practical applications.Here,we present a linear group delay spectral interferometer for achieving precise full-range distance measurements.By employing a carefully designed linear group delay(LGD)device for phase modulation of the comb modes,interference can occur and be easily measured at any position.Our approach effectively eliminates the dead zones and ambiguities in comb-based ranging,without the need for cumbersome auxiliary scanning reference devices or reliance on complex high-repetition-rate combs or high-resolution spectrometers.We conducted length metrology experiments using a mode-locked comb referenced to a rubidium clock,achieving a large nonambiguity range up to 0.3 m,covering the entire measurement period.The maximum deviation compared to a laser interferometer was less than 1.5μm,and the minimum Allan deviation during long-term measurements reached 5.47 nm at a 500 s averaging time.The approach ensures high accuracy while maintaining a simple structure,without relying on complex external devices,thereby propelling the practical implementation of comb-based length metrology.展开更多
In this study,we synthesize a catalyst comprising cobalt nanoparticles supported on MXene by pyrolyzing a composite in a N2 environment.Specifically,the composite comprises a bimetallic Zn/Co zeolitic imidazole framew...In this study,we synthesize a catalyst comprising cobalt nanoparticles supported on MXene by pyrolyzing a composite in a N2 environment.Specifically,the composite comprises a bimetallic Zn/Co zeolitic imidazole framework grown in situ on the outer surface of MXene.The catalytic efficiency of the catalyst is tested for the self-coupling of 4-methoxybenzylamine to produce value-added imine,where atmospheric oxygen(1 atm)is used as the oxidant.Based on the results,the catalyst displayed impressive catalytic activity,achieving 95.4%yield of the desired imine at 383 K for 8 h.Furthermore,the catalyst showed recyclability and tolerance toward benzylamine substrates with various functional groups.The outstanding performance of the catalyst is primarily attributed to the synergetic catalytic effect between the cobalt nanoparticles and MXene support,while also benefiting from the three-dimensional porous structure.Additionally,a preliminary investigation of potential reaction mechanisms is conducted.展开更多
Soliton generation schemes have attracted considerable scholarly attention.This paper introduces a novel backward tuning method for the reversible generation of dissipative Kerr solitons(DKSs).Reversible soliton gener...Soliton generation schemes have attracted considerable scholarly attention.This paper introduces a novel backward tuning method for the reversible generation of dissipative Kerr solitons(DKSs).Reversible soliton generation relies on the thermal stabilization of the auxiliary laser,coupled with backward tuning of the pump laser,significantly increasing the range of soliton steps by over 10 times.Moreover,the method alleviates the stringent auxiliary laser detuning requirement.By adjusting the detuning of the auxiliary laser,diverse numbers of solitons can be deterministically generated,enhancing both flexibility and precision.展开更多
The authors propose a distributed field mapping algorithm that drives a team of robots to explore and learn an unknown scalar field using a Gaussian Process(GP).The authors’strategy arises by balancing exploration ob...The authors propose a distributed field mapping algorithm that drives a team of robots to explore and learn an unknown scalar field using a Gaussian Process(GP).The authors’strategy arises by balancing exploration objectives between areas of high error and high variance.As computing high error regions is impossible since the scalar field is unknown,a bio-inspired approach known as Speeding-Up and Slowing-Down is leveraged to track the gradient of the GP error.This approach achieves global field-learning convergence and is shown to be resistant to poor hyperparameter tuning of the GP.This approach is validated in simulations and experiments using 2D wheeled robots and 2D flying mini-ature autonomous blimps.展开更多
Laser-based light detection and ranging(lidar)plays a significant role in both scientific and industrial areas.However,it is difficult for existing lidars to achieve high speed,high precision,and long distance simulta...Laser-based light detection and ranging(lidar)plays a significant role in both scientific and industrial areas.However,it is difficult for existing lidars to achieve high speed,high precision,and long distance simultaneously.Here,we demonstrate a high-performance lidar based on a chip-scaled soliton microcomb(SMC)that can realize all three specialties simultaneously.Aided by the excellent properties of ultrahigh repetition rate and the smooth envelope of the SMC,traditional optical frequency comb(OFC)-based dispersive interferometry is heavily improved and the measuring dead zone induced by the mismatch between the repetition rate of the OFC and resolution of the optical spectrum analyzer is totally eliminated.Combined with an auxiliary dual-frequency phase-modulated laser range finder,the none-dead-zone measurable range ambiguity is extended up to 1500 m.The proposed SMC lidar is experimentally implemented in both indoor and outdoor environment.In the outdoor baseline field,real-time,high-speed(up to 35 k Hz)measurement of a long distance of^1179 m is achieved with a minimum Allan deviation of 5.6μm at an average time of 0.2 ms(27 nm at an average time of 1.8 s after high-pass filtering).The present SMC lidar approaches a compact,fast,high-precision,and none-dead zone long-distance ranging system,aimed at emerging applications of frontier basic scientific research and advances in industrial manufacturing.展开更多
Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magn...Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magnetic MIL-100 （Fe）@SiO2@Fe3O4 microspheres with a novel core-shell structure were fabricated by the in-situ self-assembly of a metal-organic MIL- 100（Fe） framework around pre-synthesized magnetic SiO2@Fe3O4 particles under relatively mild and environmentally benign conditions. The catalytic activity of the MIL-100（Fe）@SiO2@Fe3O4 catalyst was tested for the liquid-phase acetalization of benzaldehyde and glycol. The MIL-100（Fe）@SiO2@Fe3O4 catalyst has a significant amount of accessible Lewis acid sites and therefore exhibited good acetalization catalytic activity. Moreover, due to its superparamagnetism properties, the heterogeneous MIL-100（Fe）@SiO2@Fe3O4 catalyst can be easily isolated from the reaction system within a few seconds by simply using an external magnet. The catalyst could then be reused at least eight times without significant loss in catalytic efficiency.展开更多
基金supported by Zhejiang Provincial Key R&D Project(No.2021C01056)the Programme of Introducing Talents of Discipline to Universities(No.D17008).
文摘Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showing a high activity in the catalytic oxidation of HCl to Cl_(2).The results on some extensive characterizations of both Ce-doped TiO_(2)carriers and their supported RuO_(2)catalysts show that the doping of Ce into TiO_(2)can effectively change the lattice parameters of TiO_(2)to improve the dispersion of the active RuO_(2)species on the carrier,which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions.This work provides some scientific basis and technical support for chlorine recycling.
基金support from the Scientific Research Fund of Zhejiang Provincial Education Department(Y202353855)the Zhejiang Provincial Key R&D Project(2021C01056)+1 种基金the Programme of Introducing Talents of Discipline to Universities(No.D17008)the National Natural Science Foundation of China(22208312).
文摘Three large π-conjugated and imine-based COFs,named TFP-TAB,TFP-TTA,and TTA-TTB,were synthesized via the ordered incorporation of benzene and triazine rings in the same host framework to study how the structural units affect the efficiency of CO_(2)photoreduction.Results from both experiments and density-functional theory(DFT)calculations indicate the separation and transfer of the photoinduced charges is highly related to the triazine-N content and the conjugation degree in the skeletons of COFs.High-efficiency CO_(2)photoreduction can be achieved by rationally adjusting the number and position of both benzene and triazine rings in the COFs.Specifically,TTA-TTB,with orderly interlaced triazine-benzene heterojunctions,can suppress the recombination probability of electrons and holes,which effectively immobilizes the key species(COOH)and lowers the free energy change of the potential-determining step,and thus exhibits a superior visible-light-induced photocatalytic activity that yields 121.7 μmol HCOOH g^(-1)h^(-1).This research,therefore,helps to elucidate the effects of the different structural blocks in COFs on inherent heterogeneous photocatalysis for CO_(2)reduction at a molecular level.
基金supported by the Jilin Provincial Science and Technology Development Plan Project(No.20220508003RC)the National Natural Science Foundation of China(52202440,52003012)。
文摘Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.
基金the National Natural Science Foun-dation of China(Grant No.52375546)the National Key Research and Development Program of China(Grant No.2022YFF0705701).
文摘Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed gas sensing system basedon optical frequency comb (OFC) calibrated frequency-modulated continuous-wave (FMCW) tuning nonlinearity. Thesystem can be used for multi-parameter synchronous measurement of gas absorption spectrum and multiplexed opticalpath. Multi-channel parallel detection is realized by combining wavelength division multiplexing (WDM) and frequencydivision multiplexing (FDM) techniques. By introducing nonlinear optical crystals, broadband spectrum detection is simultaneouslyachieved over a bandwidth of hundreds of nanometers. An OFC with ultra-high frequency stability is used asthe frequency calibration source, which guarantees the measurement accuracy. The test samples involve H13C14N, C_(2)H_(2)and Rb vapor cells of varying densities and 5 parallel measurement experiments are designed. The results show that themeasurement accuracies of spectral absorption line and the optical path are 150 MHz and 20 m, respectively. The schemeoffers the advantages of multiplexed, multi-parameter, wide spectrum and high resolution detection, which can realize theidentification of multi-gas components and the high-precision inversion of absorption lines under different environments.The proposed sensor demonstrates great potential in the field of high-resolution absorption spectrum measurement for gassensing applications.
文摘In a polluted environment, considering the biological population infected with a kind of disease and hunted by human beings, we formulate a nonautonomous SIR population-epidemic model with time-varying impulsive release and general nonlinear incidence rate and investigate dynamical behaviors of the model. Under the reasonable assumptions, the sufficient conditions which guarantee the globally attractive of the disease-free periodic solution and the permanence of the infected fish are established, that is, the infected fish dies out if , whereas the disease persists if . To substantiate our theoretical results, extensive numerical simulations are performed for a hypothetical set of parameter values.
基金financial support from the Zhejiang Provincial Key R&D Project (No.2019C03118)the Programme of Introducing Talents of Discipline to Universities (No.D17008)。
文摘Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to produce effective and efficient photocatalysts for CO_(2)reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO_(2)reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO_(2)reduction performance in order to achieve a long-term sustainability. Metalorganic frameworks(MOFs) are recently emerging as a new type of photocatalysts for CO_(2)reduction due to their excellent CO_(2)adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO_(2)reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO_(2)reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers,and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles(NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO_(2)reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO_(2)conversion.
基金We gratefully acknowledge financial support from the Zhejiang Provincial Key R&D Project(No.2019C03118)the Programme of Introducing Talents of Discipline to Universities(No.D17008).
文摘The reduction of CO_(2)into high value-added chemicals and fuels by a photocatalytic technology can relieve energy shortages and the environmental problems caused by greenhouse effects.In the current work,an amino-functionalized zirconium metal organic framework(Zr-MOF)was covalently modified with different functional groups via the condensation of Zr-MOF with 2-pyridinecarboxaldehyde(PA),salicylaldehyde(SA),benzaldehyde(BA),and trifluoroacetic acid(TA),named Zr-MOF-X(X=PA,SA,BA,and TA),respectively,through the post-synthesis modification.Compared with Zr-MOF and Zr-MOF-TA,the introduction of PA,SA,or BA into the framework of Zr-MOF can not only enhance the visible-light harvesting and CO_(2)capture,but also accelerate the photogenerated charge separation and transfer,thereby improving the photocatalytic ability of Zr-MOF for CO_(2)reduction.These results indicate that the modification of Zr-MOF with electron-donating groups can promote the photocatalytic CO_(2)reduction.Therefore,the current work provides an instructive approach to improve the photocatalytic efficiency of CO_(2)reduction through the covalent modification of MOFs.
文摘This paper proposes a vector-borne plant disease model with discontinuous treatment strategies. Constructing Lyapunov function and applying non-smooth theory to analyze discontinuous differential equations, the basic reproductive number R0 is proved, which determines whether the plant disease will be extinct or not. If R0 R0 > 1 , there exists a unique endemic equilibrium which is globally stable. The numerical simulations are provided to verify our theoretical results, which indicate that after infective individuals reach some level, strengthening treatment measures is proved to be beneficial in controlling disease transmission.
文摘In this paper, a Schistosomiasis japonicum model incorporating time delay is proposed which represents the developmental time from cercaria penetration through skins of human hosts to egg laying. By linearizing the system at the positive equilibrium and analyzing the associated characteristic equations, the local stability of the equilibria is investigated. And it proves that Hopf bifurcations occur when the time delay passes through a sequence of critical value. Furthermore, the explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions are derived by using techniques from the normal form theory and Center Manifold Theorem. Some numerical simulations which support our theoretical analysis are also conducted.
基金supported by the National Key Research and Development Program of China(No.2022YFF0705701)the National Natural Science Foundation of China(No.52375546)。
文摘Accurately perceiving the multidimensional geometric information of complex equipment is crucial for improving product quality and production efficiency.We propose a multichannel time-domain wavelength division multiplexing frequency modulated continuous wave(FMCW)LiDAR integrated with the optical switch system scheme.This enables the implementation of time-domain wavelength division multiplexing technology for FMCW lasers,achieving the unified transmission of multi-length information through a single optical fiber channel.This system scheme enables parallel measurement of multiple targets and enhances the measurement accuracy of single targets by measuring the mean through multichannels,featuring versatility.In experiment,we achieved an overall absolute distance measurement accuracy better than 14μm and individual channel accuracy better than 20μm for non-cooperative targets at a distance of 1.3 m.The overall measurement standard deviation reached 14.73μm,and the minimum Allan deviation was 189 nm at a 2.84 s averaging time.Additionally,we demonstrated 3D imaging experiments with“TIF”patterned cardboard and corridor stairs,obtained data precision better than 0.8 cm,and achieved high reliability in 3D imaging.
基金supported by the National Natural Science Foundation of China(No.62175116)the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(No.NY223154)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_0970)。
文摘In this paper,an all-optical tuning scheme of a multi-walled carbon nanotube(MWCNT)-coated microcavity is introduced,achieving high-speed precise resonance control across the free spectral range(FSR).A modulation laser input through the microcavity tail fiber adjusts the resonance peak position,achieving a tuning efficiency of 107.3 pm/mW below 15 mW,with a maximum range exceeding one FSR and a response time of~20 ms.Combined with a fixed-wavelength pump,this scheme can precisely control the microcomb states.The scheme offers high tuning efficiency,simple fabrication,and low cost,making it suitable for applications in microcomb control and optical filters.
基金supported by the National Natural Science Foundation of China(No.52375546)。
文摘In this research,we report a two-dimensional pose measurement scheme based on a metasurface array reflector,which enables absolute tracking of both linear and angular positions.The metasurface array reflector,utilizing the tailored optical field characteristics of a plasmonic absorption structure,simultaneously responds to linear and angular displacements within the illuminated optical field range and provides a characteristic absolute code to the receiving end.This code can be used to map the target's linear and angular position.By matching it with a pre-established template network,it is possible to track the target's absolute position.Under μm-level linear displacements and μrad-level angular displacements,we achieved precise two-dimensional linear and angular tracking and positioning based on this device.
基金National Natural Science Foundation of China(62205036)National Key Research and Development Program of China(2023YFF0715701)+1 种基金China Postdoctoral Science Foundation(2021M700614)Chongqing Natural Science Foundation(cstc2021jcyj-bsh X0083)。
文摘The optical frequency comb serves as a powerful tool for distance measurement by integrating numerous stable optical modes into interferometric measurements,enabling unprecedented absolute measurement precision.Nonetheless,due to the periodicity of its pulse train,the comb suffers from measurement dead zones and ambiguities,thereby impeding its practical applications.Here,we present a linear group delay spectral interferometer for achieving precise full-range distance measurements.By employing a carefully designed linear group delay(LGD)device for phase modulation of the comb modes,interference can occur and be easily measured at any position.Our approach effectively eliminates the dead zones and ambiguities in comb-based ranging,without the need for cumbersome auxiliary scanning reference devices or reliance on complex high-repetition-rate combs or high-resolution spectrometers.We conducted length metrology experiments using a mode-locked comb referenced to a rubidium clock,achieving a large nonambiguity range up to 0.3 m,covering the entire measurement period.The maximum deviation compared to a laser interferometer was less than 1.5μm,and the minimum Allan deviation during long-term measurements reached 5.47 nm at a 500 s averaging time.The approach ensures high accuracy while maintaining a simple structure,without relying on complex external devices,thereby propelling the practical implementation of comb-based length metrology.
基金the financial support from the National Natural Science Foundation of China(Grant No.21576243).
文摘In this study,we synthesize a catalyst comprising cobalt nanoparticles supported on MXene by pyrolyzing a composite in a N2 environment.Specifically,the composite comprises a bimetallic Zn/Co zeolitic imidazole framework grown in situ on the outer surface of MXene.The catalytic efficiency of the catalyst is tested for the self-coupling of 4-methoxybenzylamine to produce value-added imine,where atmospheric oxygen(1 atm)is used as the oxidant.Based on the results,the catalyst displayed impressive catalytic activity,achieving 95.4%yield of the desired imine at 383 K for 8 h.Furthermore,the catalyst showed recyclability and tolerance toward benzylamine substrates with various functional groups.The outstanding performance of the catalyst is primarily attributed to the synergetic catalytic effect between the cobalt nanoparticles and MXene support,while also benefiting from the three-dimensional porous structure.Additionally,a preliminary investigation of potential reaction mechanisms is conducted.
基金supported by the National Key Research and Development Program of China(No.2020YFB2010701)the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(No.NY223154).
文摘Soliton generation schemes have attracted considerable scholarly attention.This paper introduces a novel backward tuning method for the reversible generation of dissipative Kerr solitons(DKSs).Reversible soliton generation relies on the thermal stabilization of the auxiliary laser,coupled with backward tuning of the pump laser,significantly increasing the range of soliton steps by over 10 times.Moreover,the method alleviates the stringent auxiliary laser detuning requirement.By adjusting the detuning of the auxiliary laser,diverse numbers of solitons can be deterministically generated,enhancing both flexibility and precision.
文摘The authors propose a distributed field mapping algorithm that drives a team of robots to explore and learn an unknown scalar field using a Gaussian Process(GP).The authors’strategy arises by balancing exploration objectives between areas of high error and high variance.As computing high error regions is impossible since the scalar field is unknown,a bio-inspired approach known as Speeding-Up and Slowing-Down is leveraged to track the gradient of the GP error.This approach achieves global field-learning convergence and is shown to be resistant to poor hyperparameter tuning of the GP.This approach is validated in simulations and experiments using 2D wheeled robots and 2D flying mini-ature autonomous blimps.
基金Key Projects Supported by Science and Technology of Tianjin(18YFZCGX00920)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2016353)+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB24030600)National Key Research and Development Program of China(2018YFB2003501,2018YFF0212702)National Natural Science Foundation of China(51675380,51775379,61635013,61675231,61705257,61805277)。
文摘Laser-based light detection and ranging(lidar)plays a significant role in both scientific and industrial areas.However,it is difficult for existing lidars to achieve high speed,high precision,and long distance simultaneously.Here,we demonstrate a high-performance lidar based on a chip-scaled soliton microcomb(SMC)that can realize all three specialties simultaneously.Aided by the excellent properties of ultrahigh repetition rate and the smooth envelope of the SMC,traditional optical frequency comb(OFC)-based dispersive interferometry is heavily improved and the measuring dead zone induced by the mismatch between the repetition rate of the OFC and resolution of the optical spectrum analyzer is totally eliminated.Combined with an auxiliary dual-frequency phase-modulated laser range finder,the none-dead-zone measurable range ambiguity is extended up to 1500 m.The proposed SMC lidar is experimentally implemented in both indoor and outdoor environment.In the outdoor baseline field,real-time,high-speed(up to 35 k Hz)measurement of a long distance of^1179 m is achieved with a minimum Allan deviation of 5.6μm at an average time of 0.2 ms(27 nm at an average time of 1.8 s after high-pass filtering).The present SMC lidar approaches a compact,fast,high-precision,and none-dead zone long-distance ranging system,aimed at emerging applications of frontier basic scientific research and advances in industrial manufacturing.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 21576243） and the Public Project of Zhejiang Province of China （2016C37057）.
文摘Abstract Heterogeneous catalysts with convenient recyclability and reusability are vitally important to reduce the cost of catalysts as well as to avoid complex separation and recovery operations. In this regard, magnetic MIL-100 （Fe）@SiO2@Fe3O4 microspheres with a novel core-shell structure were fabricated by the in-situ self-assembly of a metal-organic MIL- 100（Fe） framework around pre-synthesized magnetic SiO2@Fe3O4 particles under relatively mild and environmentally benign conditions. The catalytic activity of the MIL-100（Fe）@SiO2@Fe3O4 catalyst was tested for the liquid-phase acetalization of benzaldehyde and glycol. The MIL-100（Fe）@SiO2@Fe3O4 catalyst has a significant amount of accessible Lewis acid sites and therefore exhibited good acetalization catalytic activity. Moreover, due to its superparamagnetism properties, the heterogeneous MIL-100（Fe）@SiO2@Fe3O4 catalyst can be easily isolated from the reaction system within a few seconds by simply using an external magnet. The catalyst could then be reused at least eight times without significant loss in catalytic efficiency.
