Background:Primary liver cancer poses a significant global health burden,with projections indicating a surpassing of one million cases by 2025.Cuproptosis,a copper-dependent mechanism of cell death,plays a crucial rol...Background:Primary liver cancer poses a significant global health burden,with projections indicating a surpassing of one million cases by 2025.Cuproptosis,a copper-dependent mechanism of cell death,plays a crucial role in the pathogenesis,progression,and prognosis of various cancers,including hepatocellular carcinoma(HCC).Purpose:This study aimed to develop a prognostic model for HCC based on cuproptosis-related genes,utilizing clinical data and gene expression profiles from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases.Materials and Methods:Clinical features and gene expression data of HCC patients were collected from publicly available databases.Patients from TCGA were randomly divided into training and testing sets,and Lasso Cox regression was applied to develop a predictive model using cuproptosis-related genes.Results:The analysis identified Copper Metabolism Domain Containing 1(COMMD1)as a potential prognostic marker for HCC,with deletion of this gene impacting disease progression.Cellular functional experiments validated the role of COMMD1 in HCC.Conclusions:COMMD1 emerges as a promising candidate for HCC treatment,with implications for prognosis prediction and therapeutic targeting.展开更多
Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films a...Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films above 1000℃were studied in situ by TEM at the nanoscale.The Pt films degraded mainly through void nucleation and growth on the Pt-SiN_(x)interface.Voids preferentially formed at the grain boundary and triple junction intersections with the interface.At temperatures above 1040℃,the voids nucleated at both the grain boundaries and inside the Pt grains.A stress simulation of the suspended membrane suggests the existence of local tensile stress in the Pt film,which promotes the nucleation of voids at the Pt-Si Nxinterface.The grain-boundary-dominated mass transportation renders the voids grow preferentially at GBs and triple junctions in a Pt film.Additionally,under the influence of an applied current,the voids that nucleated inside Pt grains grew to a large size and accelerated the degradation of the Pt film.展开更多
The concentration and velocity fields of two refractive index matched miscible shear-thinning fluids in a lid-driven cavity were investigated by using planar laser-induced fluorescence and particle image velocimetry,a...The concentration and velocity fields of two refractive index matched miscible shear-thinning fluids in a lid-driven cavity were investigated by using planar laser-induced fluorescence and particle image velocimetry,as well by computational fluid dynamics.Quantitative analyses show that the results obtained by flow simulations with the species transport model are in good agreement with the experimental results.The effects of different parameters were studied by using the intensity of segregation.For two fluids with the same rheological parameters,the relative amounts of liquids H_(1)/H and the power-law index n dominate the mixing process while the Reynolds number Re plays a marginal role.As for two fluids with density difference,buoyancy has significant influence on the mixing process.The dimensionless group Ar/Re(redefined such as to include shear thinning behavior)is proposed for assessing the effect of buoyancy and rheological properties on the mixing of miscible shear-thinning fluids.展开更多
Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the prob...Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.展开更多
This paper proposes a novel fixed-time sliding mode control approach for trajectory-tracking tasks of a mecanum-wheeled omnidirectional mobile robot.First,the idea of two-phase attractors is introduced into the domain...This paper proposes a novel fixed-time sliding mode control approach for trajectory-tracking tasks of a mecanum-wheeled omnidirectional mobile robot.First,the idea of two-phase attractors is introduced into the domain of sliding mode control,and a new fixed-time sliding surface is proposed.Then,according to this sliding surface,a new type of nonsingular fast terminal sliding mode control algorithm is designed for the omnidirectional mobile robot,which can realize a fast fixed-time convergence property.The stability of the control system is proven scrupulously,and a guideline for control-parameter tuning is expounded.Finally,experiments are implemented to test the trajectory-tracking performance of the robot.Experimental results demonstrate the superiority of the proposed sliding surface and the corresponding control scheme in comparison with benchmark controllers.展开更多
Bubble column reactors can be simulated by the two fluid model(TFM) coupled with the population balance equation(PBE). For the large industrial bubble columns, the compressibility due to the pressure difference may in...Bubble column reactors can be simulated by the two fluid model(TFM) coupled with the population balance equation(PBE). For the large industrial bubble columns, the compressibility due to the pressure difference may introduce notable bubble size variation. In order to address the compressibility effect, the PBE should be reformulated and coupled with the compressible TFM. In this work, the PBE with a compressibility term was formulated from single bubble dynamics, the mean Sauter diameters predicted by the compressible TFM coupled with the PBE were compared with the analytical solutions obtained by the ideal gas law. It was proven that the mesoscale formulations presented in this work were physically consistent with the macroscale modeling. It can be used to simulate large industrial plants when the compressibility induced bubble size variation is important.展开更多
Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid ...Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid catalyst Co-Bent(bentonite supported cobalt)was prepared by blending method for MgSO_(3) oxidation with bentonite as the carrier and cobalt as the active component.At the calcination temperature of 550℃ and the Co loading level of 3 wt.%,the catalyst showed excellent catalytic performance for the oxidation of high concentration MgSO_(3) slurry,and the oxidation rate of MgSO_(3) was 0.13 mol/(L·h).The research indicated that the active component was uniformly distributed within porous structure of the catalyst as Co_(3)O_(4),which facilitated the oxidation of SO_(3)^(2-) catalyzed by Co_(3)O_(4).Kinetic researches indicated the oxidation rate of MgSO_(3) was influenced by the catalyst dosage,the reaction temperature,the solution pH,the airflow rate,and the SO_(3)^(2-) concentration.Additionally,after recycling experiments,the regenerated catalyst retained its high catalytic performance for the MgSO_(3) oxidation.The reaction mechanism for the catalytic oxidation of MgSO_(3) by Co-Bent catalyst was also proposed.The generation of active free radicals(OH·,SO_(4)^(-)·,SO_(3)^(-)·,SO_(5)^(-)·)accelerated the MgSO_(3) oxidation.These results provide theoretical support for the treatment of MgSO_(3) and the development of durable catalyst.展开更多
Jet agitation is known as a maintenance-free stirring technique for nuclear wastewater treatment and demonstrates great potential in transport of radioactive particles.Removal processes of horizontal sediment beds dri...Jet agitation is known as a maintenance-free stirring technique for nuclear wastewater treatment and demonstrates great potential in transport of radioactive particles.Removal processes of horizontal sediment beds driven by impinging jets were experimentally investigated using image capture and processing technique.The beds were composed of heavy fine particles with particle density ranging from 3700 to 12600 kg·m^(-3) and particle diameter from 5 to 100 μm.The jet Reynolds number varied between 4300 and 9600.The single-phase large eddy simulation method was used for calculating both jet flow characteristics and wall shear stresses.The effects of jet strength,particle density,particle diameter,and bed thickness on bed mobility in terms of the critical Shields numbers were considered.Specifically,the critical Shields number was found to be intricately related to properties of particles,and independent of jet intensity.A new Shields number curve for stainless-steel particles was found,and a model was proposed to predict the transport rate of thin beds,with R^(2)=0.96.展开更多
Gross primary production(GPP)is closely associated with processes such as photosynthesis and transpiration within ecosystems,which is a vital component of the global carbon-water-energy cycle.Accurate prediction of GP...Gross primary production(GPP)is closely associated with processes such as photosynthesis and transpiration within ecosystems,which is a vital component of the global carbon-water-energy cycle.Accurate prediction of GPP in terrestrial ecosystems is essential for evaluating terrestrial carbon cycle processes.Machine learning(ML)models provide significant technical support in this domain.Presently,there is a deficiency of high-precision and robust GPP prediction variables and models.Challenges such as unclear contributions of predictive variables,extended model training durations,and limited robustness must be addressed.Solar-induced chlorophyll fluorescence(SIF),optimized multilayer perceptron neural networks,and ensemble learning models show the potential to overcome these challenges.This study aimed to develop an optimized multilayer perceptron neural network model and an ensemble learning model,while objectively assessing the capacity of SIF to predict GPP.Identifying robust models capable of enhancing the accuracy of GPP predictions was the ultimate goal.This study utilized continuous observations of SIF and meteorological data collected from 2020 to 2021 at a designated research observation station within the Populus plantation ecosystem of the Huanghuaihai agricultural protective forest system in Henan Province,China.By optimizing and evaluating the predictive accuracy and robustness of the models across different temporal scales(half-hourly and daily scales),a multi-layer perceptron(MLP)neural network optimization model based on the back propagation(BP)neural network(BPNN)algorithm(BP/MLP)and MLP and random forest(RF)integration(MLP-RF)ensemble models were constructed,utilizing SIF as the primary predictive variable for GPP.Both the BP/MLP(half-hourly scale model R^(2)=0.885,daily scale model R^(2)=0.921)and the MLP-RF(half-hourly scale model R^(2)=0.845,daily scale model R^(2)=0.914)models showed superior accuracy compared to the BPNN(half-hourly scale model R^(2)=0.841,daily scale model R^(2)=0.918)and the traditional RF(half-hourly scale model R^(2)=0.798,daily scale model R^(2)=0.867)models,with the BP/MLP model consistently outperforming the MLP-RF model.The BP/MLP model,which was optimized through particle swarm optimization(PSO),significantly enhanced the robustness of GPP predictions on a half-hourly scale and daily scale.Considering both half-hourly scale and daily scale in the PSO-BP/MLP modeling,the four indicators,light-use efficiency(LUE),photosynthetically active radiation(PAR),absorbed photosynthetically active radiation(APAR),and the variation in SIF with NIRvP(fSIF(NIRvP)),exhibited the potential for enhancing the accuracy of GPP predictions.This study employed a series of model optimization techniques to develop a GPP prediction model with enhanced performance that objectively evaluated the contributions of the predictive variables.This approach provided an innovative and effective method for assessing the carbon cycle in terrestrial ecosystems.展开更多
Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,resear...Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,research on chloroform vapor sensing is still in its early stages,primarily due to the lack of specific recognition motif.Here we report a mesoporous photonic crystal sensor incorporating carbon dots-based nanoreceptor(HMSS@CDs-PCs)for enhanced chloroform sensing.The colloidal PC packed with hollow mesoporous silica spheres provides an interconnected ordered macro-meso-hierarchical porous structure,ideal for rapid gas sensing utilizing the photonic bandgap shift as the readout signal.The as-synthesized CDs with pyridinic-N-oxide functional groups adsorbed in the hollow mesoporous silica spheres are found to not only serve as the chloroform adsorption sites,but also a molecular glue that prevents crack formation in the colloidal PC.The sensitivity of HMSS@CDs-PCs sensor is 0.79 nm ppm^(-1)and an impressively low limit of detection is 3.22 ppm,which are the best reported values in fast-response chloroform vapor sensor without multi-signal assistance.The positive response time is 7.5 s and the negative response time 9 s.Furthermore,relatively stable sensing can be maintained within a relative humidity of 20%-85%RH and temperature of 25-55℃.This study demonstrates that HMSS@CDs-PCs sensors have practical application potential in indoor and outdoor chloroform vapor detection.展开更多
Depression is an emotional disorder with a complex and diverse etiology.In recent years,the worldwide incidence of depression has shown an increasing trend and has become a serious health worldwide.Anhedonia is one of...Depression is an emotional disorder with a complex and diverse etiology.In recent years,the worldwide incidence of depression has shown an increasing trend and has become a serious health worldwide.Anhedonia is one of the core symptoms of major depressive disorder,and it has a specific impact on the condition and prognosis of patients.The N-methyl-D-aspartate receptor(NMDAR)esketamine has been found to have a specific therapeutic effect on depression.The purpose of this article was to review the possible mechanism of the ketamine molecule on anhedonia in depression,as well as the related studies on the general therapeutic effects.The results show that ketamine can improve the symptoms of anhedonia in depression as a drug and highlight the feasibility of using it.展开更多
文摘Background:Primary liver cancer poses a significant global health burden,with projections indicating a surpassing of one million cases by 2025.Cuproptosis,a copper-dependent mechanism of cell death,plays a crucial role in the pathogenesis,progression,and prognosis of various cancers,including hepatocellular carcinoma(HCC).Purpose:This study aimed to develop a prognostic model for HCC based on cuproptosis-related genes,utilizing clinical data and gene expression profiles from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases.Materials and Methods:Clinical features and gene expression data of HCC patients were collected from publicly available databases.Patients from TCGA were randomly divided into training and testing sets,and Lasso Cox regression was applied to develop a predictive model using cuproptosis-related genes.Results:The analysis identified Copper Metabolism Domain Containing 1(COMMD1)as a potential prognostic marker for HCC,with deletion of this gene impacting disease progression.Cellular functional experiments validated the role of COMMD1 in HCC.Conclusions:COMMD1 emerges as a promising candidate for HCC treatment,with implications for prognosis prediction and therapeutic targeting.
基金financially supported by the Basic Science Center Program for Multiphase Evolution in Hyper-gravity of the National Natural Science Foundation of China(51988101)NSFC Programs(Nos.52071003,91860202,11604006)+3 种基金the Beijing Municipal Education Commission Project(Nos.PXM2020014204000021 and PXM201901420400032)the Beijing Outstanding Young Scientists Projects(No.BJJWZYJH01201910005018)the Beijing Natural Science Foundation(No.Z180014)the“111 Project(No.DB18015)。
文摘Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films above 1000℃were studied in situ by TEM at the nanoscale.The Pt films degraded mainly through void nucleation and growth on the Pt-SiN_(x)interface.Voids preferentially formed at the grain boundary and triple junction intersections with the interface.At temperatures above 1040℃,the voids nucleated at both the grain boundaries and inside the Pt grains.A stress simulation of the suspended membrane suggests the existence of local tensile stress in the Pt film,which promotes the nucleation of voids at the Pt-Si Nxinterface.The grain-boundary-dominated mass transportation renders the voids grow preferentially at GBs and triple junctions in a Pt film.Additionally,under the influence of an applied current,the voids that nucleated inside Pt grains grew to a large size and accelerated the degradation of the Pt film.
基金The financial supports from the National Natural Science Foundation of China(22178014)。
文摘The concentration and velocity fields of two refractive index matched miscible shear-thinning fluids in a lid-driven cavity were investigated by using planar laser-induced fluorescence and particle image velocimetry,as well by computational fluid dynamics.Quantitative analyses show that the results obtained by flow simulations with the species transport model are in good agreement with the experimental results.The effects of different parameters were studied by using the intensity of segregation.For two fluids with the same rheological parameters,the relative amounts of liquids H_(1)/H and the power-law index n dominate the mixing process while the Reynolds number Re plays a marginal role.As for two fluids with density difference,buoyancy has significant influence on the mixing process.The dimensionless group Ar/Re(redefined such as to include shear thinning behavior)is proposed for assessing the effect of buoyancy and rheological properties on the mixing of miscible shear-thinning fluids.
基金financially supported by National Natural Science Foundation of China(22038012,32172339,and 22178142)National Key Research and Development Program(2023YF D2100603)。
文摘Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.
基金supported by the National Natural Science Foundation of China(62003305)the Natural Science Foundation of Zhejiang Province(LQ21F030015)+1 种基金the Key Research and Development Program of Zhejiang Province(2022C03029)the Public Welfare Application Research Project of Huzhou City(2022GZ15).
文摘This paper proposes a novel fixed-time sliding mode control approach for trajectory-tracking tasks of a mecanum-wheeled omnidirectional mobile robot.First,the idea of two-phase attractors is introduced into the domain of sliding mode control,and a new fixed-time sliding surface is proposed.Then,according to this sliding surface,a new type of nonsingular fast terminal sliding mode control algorithm is designed for the omnidirectional mobile robot,which can realize a fast fixed-time convergence property.The stability of the control system is proven scrupulously,and a guideline for control-parameter tuning is expounded.Finally,experiments are implemented to test the trajectory-tracking performance of the robot.Experimental results demonstrate the superiority of the proposed sliding surface and the corresponding control scheme in comparison with benchmark controllers.
文摘Bubble column reactors can be simulated by the two fluid model(TFM) coupled with the population balance equation(PBE). For the large industrial bubble columns, the compressibility due to the pressure difference may introduce notable bubble size variation. In order to address the compressibility effect, the PBE should be reformulated and coupled with the compressible TFM. In this work, the PBE with a compressibility term was formulated from single bubble dynamics, the mean Sauter diameters predicted by the compressible TFM coupled with the PBE were compared with the analytical solutions obtained by the ideal gas law. It was proven that the mesoscale formulations presented in this work were physically consistent with the macroscale modeling. It can be used to simulate large industrial plants when the compressibility induced bubble size variation is important.
基金supported by the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology (No. 2022TS10)the Taishan Industrial Experts Programthe Natural Science Foundation of Shandong Province of China (No. ZR2023ME212).
文摘Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid catalyst Co-Bent(bentonite supported cobalt)was prepared by blending method for MgSO_(3) oxidation with bentonite as the carrier and cobalt as the active component.At the calcination temperature of 550℃ and the Co loading level of 3 wt.%,the catalyst showed excellent catalytic performance for the oxidation of high concentration MgSO_(3) slurry,and the oxidation rate of MgSO_(3) was 0.13 mol/(L·h).The research indicated that the active component was uniformly distributed within porous structure of the catalyst as Co_(3)O_(4),which facilitated the oxidation of SO_(3)^(2-) catalyzed by Co_(3)O_(4).Kinetic researches indicated the oxidation rate of MgSO_(3) was influenced by the catalyst dosage,the reaction temperature,the solution pH,the airflow rate,and the SO_(3)^(2-) concentration.Additionally,after recycling experiments,the regenerated catalyst retained its high catalytic performance for the MgSO_(3) oxidation.The reaction mechanism for the catalytic oxidation of MgSO_(3) by Co-Bent catalyst was also proposed.The generation of active free radicals(OH·,SO_(4)^(-)·,SO_(3)^(-)·,SO_(5)^(-)·)accelerated the MgSO_(3) oxidation.These results provide theoretical support for the treatment of MgSO_(3) and the development of durable catalyst.
文摘Jet agitation is known as a maintenance-free stirring technique for nuclear wastewater treatment and demonstrates great potential in transport of radioactive particles.Removal processes of horizontal sediment beds driven by impinging jets were experimentally investigated using image capture and processing technique.The beds were composed of heavy fine particles with particle density ranging from 3700 to 12600 kg·m^(-3) and particle diameter from 5 to 100 μm.The jet Reynolds number varied between 4300 and 9600.The single-phase large eddy simulation method was used for calculating both jet flow characteristics and wall shear stresses.The effects of jet strength,particle density,particle diameter,and bed thickness on bed mobility in terms of the critical Shields numbers were considered.Specifically,the critical Shields number was found to be intricately related to properties of particles,and independent of jet intensity.A new Shields number curve for stainless-steel particles was found,and a model was proposed to predict the transport rate of thin beds,with R^(2)=0.96.
基金supported by the National Key R&D Program of China(No.2023YFD2200400-01)the Fundamental Scientific Research Operation of Central-level Public Welfare Scientific Research Institutes(No.CAFYBB2023MA001).
文摘Gross primary production(GPP)is closely associated with processes such as photosynthesis and transpiration within ecosystems,which is a vital component of the global carbon-water-energy cycle.Accurate prediction of GPP in terrestrial ecosystems is essential for evaluating terrestrial carbon cycle processes.Machine learning(ML)models provide significant technical support in this domain.Presently,there is a deficiency of high-precision and robust GPP prediction variables and models.Challenges such as unclear contributions of predictive variables,extended model training durations,and limited robustness must be addressed.Solar-induced chlorophyll fluorescence(SIF),optimized multilayer perceptron neural networks,and ensemble learning models show the potential to overcome these challenges.This study aimed to develop an optimized multilayer perceptron neural network model and an ensemble learning model,while objectively assessing the capacity of SIF to predict GPP.Identifying robust models capable of enhancing the accuracy of GPP predictions was the ultimate goal.This study utilized continuous observations of SIF and meteorological data collected from 2020 to 2021 at a designated research observation station within the Populus plantation ecosystem of the Huanghuaihai agricultural protective forest system in Henan Province,China.By optimizing and evaluating the predictive accuracy and robustness of the models across different temporal scales(half-hourly and daily scales),a multi-layer perceptron(MLP)neural network optimization model based on the back propagation(BP)neural network(BPNN)algorithm(BP/MLP)and MLP and random forest(RF)integration(MLP-RF)ensemble models were constructed,utilizing SIF as the primary predictive variable for GPP.Both the BP/MLP(half-hourly scale model R^(2)=0.885,daily scale model R^(2)=0.921)and the MLP-RF(half-hourly scale model R^(2)=0.845,daily scale model R^(2)=0.914)models showed superior accuracy compared to the BPNN(half-hourly scale model R^(2)=0.841,daily scale model R^(2)=0.918)and the traditional RF(half-hourly scale model R^(2)=0.798,daily scale model R^(2)=0.867)models,with the BP/MLP model consistently outperforming the MLP-RF model.The BP/MLP model,which was optimized through particle swarm optimization(PSO),significantly enhanced the robustness of GPP predictions on a half-hourly scale and daily scale.Considering both half-hourly scale and daily scale in the PSO-BP/MLP modeling,the four indicators,light-use efficiency(LUE),photosynthetically active radiation(PAR),absorbed photosynthetically active radiation(APAR),and the variation in SIF with NIRvP(fSIF(NIRvP)),exhibited the potential for enhancing the accuracy of GPP predictions.This study employed a series of model optimization techniques to develop a GPP prediction model with enhanced performance that objectively evaluated the contributions of the predictive variables.This approach provided an innovative and effective method for assessing the carbon cycle in terrestrial ecosystems.
基金supported by the National Key Research and Development Program of China(No.2022YFB3205500)National Natural Science Foundation of China(Nos.U23A20360 and 62303192)QL wishes to thank Water Research Australia(WRA 1144/21)for funding support.
文摘Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers,because of their potential harm to the respiratory system,nervous system,skin,and eyes.However,research on chloroform vapor sensing is still in its early stages,primarily due to the lack of specific recognition motif.Here we report a mesoporous photonic crystal sensor incorporating carbon dots-based nanoreceptor(HMSS@CDs-PCs)for enhanced chloroform sensing.The colloidal PC packed with hollow mesoporous silica spheres provides an interconnected ordered macro-meso-hierarchical porous structure,ideal for rapid gas sensing utilizing the photonic bandgap shift as the readout signal.The as-synthesized CDs with pyridinic-N-oxide functional groups adsorbed in the hollow mesoporous silica spheres are found to not only serve as the chloroform adsorption sites,but also a molecular glue that prevents crack formation in the colloidal PC.The sensitivity of HMSS@CDs-PCs sensor is 0.79 nm ppm^(-1)and an impressively low limit of detection is 3.22 ppm,which are the best reported values in fast-response chloroform vapor sensor without multi-signal assistance.The positive response time is 7.5 s and the negative response time 9 s.Furthermore,relatively stable sensing can be maintained within a relative humidity of 20%-85%RH and temperature of 25-55℃.This study demonstrates that HMSS@CDs-PCs sensors have practical application potential in indoor and outdoor chloroform vapor detection.
文摘Depression is an emotional disorder with a complex and diverse etiology.In recent years,the worldwide incidence of depression has shown an increasing trend and has become a serious health worldwide.Anhedonia is one of the core symptoms of major depressive disorder,and it has a specific impact on the condition and prognosis of patients.The N-methyl-D-aspartate receptor(NMDAR)esketamine has been found to have a specific therapeutic effect on depression.The purpose of this article was to review the possible mechanism of the ketamine molecule on anhedonia in depression,as well as the related studies on the general therapeutic effects.The results show that ketamine can improve the symptoms of anhedonia in depression as a drug and highlight the feasibility of using it.
