Internet gaming disorder(IGD)among junior high school students is an increasingly prominent mental health concern.It is important to look for influences behind internet gaming disorder tendency(IGDT)in the junior high...Internet gaming disorder(IGD)among junior high school students is an increasingly prominent mental health concern.It is important to look for influences behind internet gaming disorder tendency(IGDT)in the junior high school student population.The present study aimed to reveal the explanatory mechanisms underlying the association between parental psychological control(PPC)and internet gaming disorder tendency among junior high school students by testing the mediating role of core self-evaluation(CSE)and the moderating role of intentional self-regulation(ISR).Participants in present study were 735 Chinese junior high school students who completed offline self-report questionnaires on parental psychological control,core self-evaluation,intentional self-regulation,and Internet gaming disorder tendency.Analyses were conducted via mediation and moderated mediation.The results showed that:(1)Parental psychological control was positively related to junior high school students’Internet gaming disorder tendency.Core self-evaluation,and intentional self-regulation were negatively related to junior high school students’Internet gaming disorder tendency,respectively.(2)Core self-evaluation partially mediated the relationship between parental psychological control and junior high school students’Internet gaming disorder tendency.(3)Intentional self-regulation moderated the association between parental psychological control and Internet gaming disorder tendency,as well as the relationships between parental psychological control and core self-evaluation and core self-evaluation and Internet gaming disorder tendency in the mediated model.Based on these findings,we believe that there is a need to weaken parental psychological control,strengthen junior high school students’core self-evaluation and intentional self-regulation,and to recognize the important role of parents as well as their children’s personal positive traits in the healthy development of junior high school students.展开更多
The present study discusses the relationship among Chinese adolescents’parental involvement,core self-evaluation,and school adaptation.The Parental Involvement Behavior Questionnaire,Core Self-Evaluations Scale(CSES)...The present study discusses the relationship among Chinese adolescents’parental involvement,core self-evaluation,and school adaptation.The Parental Involvement Behavior Questionnaire,Core Self-Evaluations Scale(CSES),and the School Adaptation Inventory were used to survey 1258 Chinese middle school students.The results showed that adolescents’school adaptation was significantly positively correlated with parental involvement and core self-evaluation.Furthermore,parental involvement and core self-evaluation were positively correlated.Mediation analysis found that core self-evaluation had partially mediated the relationship between adolescents’parental involvement and school adaption.Parental involvement could directly affect adolescents’school adaptation and indirectly affect school adaptation through the mediating effect of core self-evaluation.The present study results suggested that parents and educators could improve adolescents’school adaptation by increasing parental involvement and enhancing the adolescents’core self-evaluation.展开更多
This study aimed to investigate the link between the exposure to intimate partner violence(IPV),core self-evaluations(CSE),and psychological adaptation of Chinese adolescents,through analysis of the results from the S...This study aimed to investigate the link between the exposure to intimate partner violence(IPV),core self-evaluations(CSE),and psychological adaptation of Chinese adolescents,through analysis of the results from the Survey of Children’s Exposure to Domestic Violence Scale,Core Self-Evaluations Scale,and Strengths and Difficulties Questionnaire,involving a total of 597 Chinese middle school students.It is indicated that the exposure to IPV is positively correlated with lower levels of psychological adaptation and CSE,and CSE is positively correlated with higher levels of psychological adaptation.Mediation analysis revealed that CSE partially mediated the association between the exposure to IPV and psychological adaptation.These results suggest that educators and parents should help adolescents tackle their emotional and behavioral problems by reducing the risk of IPV exposure and increasing their CSE.展开更多
Background:Components of Self,completed with the perceived social support determine the individual differences in theevaluation of a stressor and the behavioral responses toward it,such as health-related anxiety.The s...Background:Components of Self,completed with the perceived social support determine the individual differences in theevaluation of a stressor and the behavioral responses toward it,such as health-related anxiety.The study set as a goal theanalysis of associations between the components of Self,such as self-evaluation,sense of coherence,perceived social support,and reported health-related anxiety in an adult sample.Methods:147 adults from the 18–73 age group(mean age 37.5)voluntarily completed the questionnaire through Qualtrics online platform containing the Short Health Anxiety Inventory,Core Self-Evaluation Scale,Social Support Assessing Scale,and one Health Self-Evaluation Item.Results:ANOVA foundrelevant differences in total scores and subscales’scores of the health anxiety scale depending on the positive self-evaluation.Linear regression shows that the analyzed variables were responsible for the prediction of a higher value on the“Perceivedprobability of becoming ill”subscale in a proportion of 45.6%and for the“Perceived consequence of illness”subscale in aproportion of 20.2%The predictive value of the linear regression model for the total score on the health anxiety scale was46.3%.Our findings show that negative Core Self-Evaluation is linked with perceived health anxiety.Conclusions:Selfevaluation,sense of coherence and perceived social support influence the perceived health and can explain the differences inthe reported health-related anxiety.展开更多
Informed by implicit leadership theories, this study investigates contemporary Chinese employees' preferences for paternalistic leadership (including three components: moral leadership, benevolent leadership and au...Informed by implicit leadership theories, this study investigates contemporary Chinese employees' preferences for paternalistic leadership (including three components: moral leadership, benevolent leadership and authoritarian leadership) and transformational leadership. It further examines the relationship between power distance orientation, core self-evaluation (CSE) and leadership preferences. The study finds that contemporary Chinese employees most prefer moral leadership, but are also highly receptive to transformational leadership. They prefer authoritarian leadership least. Moreover, preferences for authoritarian leadership are predicated on followers' power distance orientation. However, the opposite is true for moral leadership. CSE is positively related to followers' preference for authoritarian leadership, benevolent leadership and transformational leadership, but not except for moral leadership. A positive interaction effect is found between power distance orientation and CSE with regard to authoritarian leadership preference. The theoretical and practical implications of the findings are discussed.展开更多
This study aims to examine the relationship between authentic leadership and employee proactive behavior. Based on self-determination theory, we argue that such a relationship is sequentially mediated by psychological...This study aims to examine the relationship between authentic leadership and employee proactive behavior. Based on self-determination theory, we argue that such a relationship is sequentially mediated by psychological empowerment and core self-evaluations. In addition, political skill plays a moderating role in the third stage. These hypotheses are validated by a sample of 65 leaders and 275 subordinates from two private enterprises in China's Mainland. Results show that authentic leadership Clime I) influences employees' proactive behavior Clime 3) through the psychological empowerment (Time I) and core self-evaluations of employees (Time 2), and the relationship between core self-evaluations and proactive behavior is positively moderated by employees' political skill. In addition, bootstrapping results also verify the moderating role played by employees' political skill in the indirect relationship between authentic leadership and proactive behavior through core self-evaluations. Theoretical and managerial implications are further discussed in the light of these findings.展开更多
Material composition and structural design are important factors influencing the electromagnetic wave(EMW)absorption performance of materials.To alleviate the impedance mismatch attributed to the high dielectric const...Material composition and structural design are important factors influencing the electromagnetic wave(EMW)absorption performance of materials.To alleviate the impedance mismatch attributed to the high dielectric constant of Ti_(3)C_(2)T_(x)MXene,we have successfully synthesized core‐shell structured SiO_(2)@MXene@MoS_(2)nanospheres.This architecture,comprising SiO_(2) as the core,MXene as the intermediate layer,and MoS_(2) as the outer shell,is achieved through an electrostatic self‐assembly method combined with a hydrothermal process.This complex core‐shell structure not only provides a variety of loss mechanisms that effectively dissipate electromagnetic energy but also prevents self‐aggregation of MXene and MoS_(2) nanosheets.Notably,the synergistic combination of SiO_(2) and MoS_(2) with highly conductive MXene enables the suitable dielectric constant of the composites,ensuring optimal impedance matching.Therefore,the core‐shell structured SiO_(2)@MXene@MoS_(2) nanospheres exhibit excellent EMW absorption performance,featuring a remarkable minimum reflection loss(RL_(min))of−52.11 dB(2.4 mm).It is noteworthy that these nanospheres achieve an ultra‐wide effective absorption bandwidth(EAB)of 6.72 GHz.This work provides a novel approach for designing and synthesizing high‐performance EMW absorbers characterized by“wide bandwidth and strong reflection loss.”展开更多
Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclu...Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.展开更多
A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established ...A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established by the third-order shear deformation theory(TSDT),and then combined with the fluid-structure coupling conditions,and the sound insulation is solved.The theoretical results are validated by COMSOL simulation results,and the effects of the structural parameter on the sound insulation are analyzed.Finally,the standard genetic algorithm is adopted to optimize the sound insulation of the sandwich plate.展开更多
Identifying deformational mechanisms and associated structures at various scales,ranging from regional-scale structures to microscopic fabric,is crucial for the assessment of tectonic development.Thirty-three samples ...Identifying deformational mechanisms and associated structures at various scales,ranging from regional-scale structures to microscopic fabric,is crucial for the assessment of tectonic development.Thirty-three samples were taken from the Qazzaz metamorphic core complex to estimate the finite strain for felsic and mafic minerals.These samples included gneisses rocks,monzogranite,and metavolcano-sedimentary rocks for both the Thalbah and Bayda groups.Using the Rf/j and Fry methods,the axial ratios(XZ)range about 2.20 to 7.10 and 1.90 to 9.10,respectively.For various rock units,the strain measurements show moderate to highly deformation.Most of the observed samples show shallow WNW dipping along a N to WNW trend of finite strain(X).The short axes(Z)based to be subvertical foliation related with a subhorizontal foliation.The results demonstrate that contacts generated at semi-brittle to ductile deformation and that the strain of magnitude has the same value for different lithologic units.It concluded that nappe generation in orogens results from pure shear deformation.展开更多
Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostat...Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical core.The NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer time.Recent advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic relationship.In this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the NAS.The NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)model.The forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,respectively.Finally,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic tendency.Corrected by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.展开更多
Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive appearance.However,the inability of controlling and regulati...Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive appearance.However,the inability of controlling and regulating vibrations and destroying them afterward is a challenge to scientists.In this paper,the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms.A five-layer sandwich doubly curved micro-composite shell,comprising two piezoelectric layers for the sensor and actuator,is modeled by the fourth-order shear deformation theory.The core(honeycomb,truss,and corrugated)is analyzed for the bearing of transverse shear forces.The results show that the honeycomb core has a greater effect on the vibrations.When the parameters related to the core and the weight percentage of graphene increase,the frequency increases.The uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency increases.Furthermore,without taking into account the piezoelectric layers,the third-order shear deformation theory(TSDT)and fourth-order shear deformation theory(FOSDT)align closely.However,when the piezoelectric layers are incorporated,these two theories diverge significantly,with the frequencies in the FOSDT being lower than those in the TSDT.展开更多
Many networks exhibit the core/periphery structure.Core/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral nodes.Core nodes tend to be...Many networks exhibit the core/periphery structure.Core/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral nodes.Core nodes tend to be well-connected,both among themselves and to peripheral nodes,which tend not to be well-connected to other nodes.In this brief report,we propose a new method to detect the core of a network by the centrality of each node.It is discovered that such nodes with non-negative centralities often consist in the core of the networks.The simulation is carried out on different real networks.The results are checked by the objective function.The checked results may show the effectiveness of the simulation results by the centralities of the nodes on the real networks.Furthermore,we discuss the characters of networks with the single core/periphery structure and point out the scope of the application of our method at the end of this paper.展开更多
Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems ...Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems that must be resolved.To this end,a drug carrier incorporating natural magnetic cores in a zeolite framework was developed and applied to the loading of curcumin in ethanol solutions.In this system,curcumin is encapsulated in a zeolite Na(ZNA)magnetic core–shell structure(Fe@Si/ZNA),which can be easily synthesized using an in situ method.Synthesis of Fe_(3)O_(4) nanoparticles was carried out from natural materials using a co-precipitation method.Analysis of the prepared magnetic core–shell structures and composites was carried out using vibrating-sample magnetometery,Fourier transform infrared spectroscopy,transmission electron microscopy,and x-ray diffraction.The cumulative loading of curcumin in the ZNA composite with 9%nanoparticles was found to reach 90.70%with a relatively long half-life of 32.49 min.Stability tests of curcumin loading in the composite showed that adding magnetic particles to the zeolite framework also increased the stability of the composite structure.Adsorption kinetics and isotherm studies also found that the system follows the pseudo-second-order and Langmuir isotherm models.展开更多
Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic properties.In thi...Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic properties.In this paper,the M-edge spectra of La ions and the M-edge,L-edge,and K-edge spectra of Mn ions in LaMnO3 are calculated by considering both the free-ion multiplet calculation and the crystal field effects.We analyze spectral shapes,identify peak origins,and estimate the oxidation states of La and Mn ions in LaMnO3 theoretically.It is concluded that La ions in LaMnO3 predominantly exist in the trivalent state,while Mn ions exist primarily in the trivalent state with a minor presence of tetravalent ions.Furthermore,the calculated spectra are in better conformity with the experimental spectra when the proportion of Mn3+is 90%and Mn4+is 10%.This article enhances our comprehension of the oxidation states of La and Mn within the crystal and also provides a valuable guidance for spectroscopic investigations of other manganates.展开更多
With the rapid development of low-orbit satellite com-munication networks both domestically and internationally,space-terrestrial integrated networks will become the future development trend.For space and terrestrial ...With the rapid development of low-orbit satellite com-munication networks both domestically and internationally,space-terrestrial integrated networks will become the future development trend.For space and terrestrial networks with limi-ted resources,the utilization efficiency of the entire space-terres-trial integrated networks resources can be affected by the core network indirectly.In order to improve the response efficiency of core networks expansion construction,early warning of the core network elements capacity is necessary.Based on the inte-grated architecture of space and terrestrial network,multidimen-sional factors are considered in this paper,including the number of terminals,login users,and the rules of users’migration during holidays.Using artifical intelligence(AI)technologies,the regis-tered users of the access and mobility management function(AMF),authorization users of the unified data management(UDM),protocol data unit(PDU)sessions of session manage-ment function(SMF)are predicted in combination with the num-ber of login users,the number of terminals.Therefore,the core network elements capacity can be predicted in advance.The proposed method is proven to be effective based on the data from real network.展开更多
基金supported by the National Social Science Foundation of China(20BSH131).
文摘Internet gaming disorder(IGD)among junior high school students is an increasingly prominent mental health concern.It is important to look for influences behind internet gaming disorder tendency(IGDT)in the junior high school student population.The present study aimed to reveal the explanatory mechanisms underlying the association between parental psychological control(PPC)and internet gaming disorder tendency among junior high school students by testing the mediating role of core self-evaluation(CSE)and the moderating role of intentional self-regulation(ISR).Participants in present study were 735 Chinese junior high school students who completed offline self-report questionnaires on parental psychological control,core self-evaluation,intentional self-regulation,and Internet gaming disorder tendency.Analyses were conducted via mediation and moderated mediation.The results showed that:(1)Parental psychological control was positively related to junior high school students’Internet gaming disorder tendency.Core self-evaluation,and intentional self-regulation were negatively related to junior high school students’Internet gaming disorder tendency,respectively.(2)Core self-evaluation partially mediated the relationship between parental psychological control and junior high school students’Internet gaming disorder tendency.(3)Intentional self-regulation moderated the association between parental psychological control and Internet gaming disorder tendency,as well as the relationships between parental psychological control and core self-evaluation and core self-evaluation and Internet gaming disorder tendency in the mediated model.Based on these findings,we believe that there is a need to weaken parental psychological control,strengthen junior high school students’core self-evaluation and intentional self-regulation,and to recognize the important role of parents as well as their children’s personal positive traits in the healthy development of junior high school students.
文摘The present study discusses the relationship among Chinese adolescents’parental involvement,core self-evaluation,and school adaptation.The Parental Involvement Behavior Questionnaire,Core Self-Evaluations Scale(CSES),and the School Adaptation Inventory were used to survey 1258 Chinese middle school students.The results showed that adolescents’school adaptation was significantly positively correlated with parental involvement and core self-evaluation.Furthermore,parental involvement and core self-evaluation were positively correlated.Mediation analysis found that core self-evaluation had partially mediated the relationship between adolescents’parental involvement and school adaption.Parental involvement could directly affect adolescents’school adaptation and indirectly affect school adaptation through the mediating effect of core self-evaluation.The present study results suggested that parents and educators could improve adolescents’school adaptation by increasing parental involvement and enhancing the adolescents’core self-evaluation.
基金funded by China’s National Social Science Fund,“The effect of community violence exposure on middle school students’social adjustment and its intervention countermeasures”(16BSH102).
文摘This study aimed to investigate the link between the exposure to intimate partner violence(IPV),core self-evaluations(CSE),and psychological adaptation of Chinese adolescents,through analysis of the results from the Survey of Children’s Exposure to Domestic Violence Scale,Core Self-Evaluations Scale,and Strengths and Difficulties Questionnaire,involving a total of 597 Chinese middle school students.It is indicated that the exposure to IPV is positively correlated with lower levels of psychological adaptation and CSE,and CSE is positively correlated with higher levels of psychological adaptation.Mediation analysis revealed that CSE partially mediated the association between the exposure to IPV and psychological adaptation.These results suggest that educators and parents should help adolescents tackle their emotional and behavioral problems by reducing the risk of IPV exposure and increasing their CSE.
文摘Background:Components of Self,completed with the perceived social support determine the individual differences in theevaluation of a stressor and the behavioral responses toward it,such as health-related anxiety.The study set as a goal theanalysis of associations between the components of Self,such as self-evaluation,sense of coherence,perceived social support,and reported health-related anxiety in an adult sample.Methods:147 adults from the 18–73 age group(mean age 37.5)voluntarily completed the questionnaire through Qualtrics online platform containing the Short Health Anxiety Inventory,Core Self-Evaluation Scale,Social Support Assessing Scale,and one Health Self-Evaluation Item.Results:ANOVA foundrelevant differences in total scores and subscales’scores of the health anxiety scale depending on the positive self-evaluation.Linear regression shows that the analyzed variables were responsible for the prediction of a higher value on the“Perceivedprobability of becoming ill”subscale in a proportion of 45.6%and for the“Perceived consequence of illness”subscale in aproportion of 20.2%The predictive value of the linear regression model for the total score on the health anxiety scale was46.3%.Our findings show that negative Core Self-Evaluation is linked with perceived health anxiety.Conclusions:Selfevaluation,sense of coherence and perceived social support influence the perceived health and can explain the differences inthe reported health-related anxiety.
文摘Informed by implicit leadership theories, this study investigates contemporary Chinese employees' preferences for paternalistic leadership (including three components: moral leadership, benevolent leadership and authoritarian leadership) and transformational leadership. It further examines the relationship between power distance orientation, core self-evaluation (CSE) and leadership preferences. The study finds that contemporary Chinese employees most prefer moral leadership, but are also highly receptive to transformational leadership. They prefer authoritarian leadership least. Moreover, preferences for authoritarian leadership are predicated on followers' power distance orientation. However, the opposite is true for moral leadership. CSE is positively related to followers' preference for authoritarian leadership, benevolent leadership and transformational leadership, but not except for moral leadership. A positive interaction effect is found between power distance orientation and CSE with regard to authoritarian leadership preference. The theoretical and practical implications of the findings are discussed.
文摘This study aims to examine the relationship between authentic leadership and employee proactive behavior. Based on self-determination theory, we argue that such a relationship is sequentially mediated by psychological empowerment and core self-evaluations. In addition, political skill plays a moderating role in the third stage. These hypotheses are validated by a sample of 65 leaders and 275 subordinates from two private enterprises in China's Mainland. Results show that authentic leadership Clime I) influences employees' proactive behavior Clime 3) through the psychological empowerment (Time I) and core self-evaluations of employees (Time 2), and the relationship between core self-evaluations and proactive behavior is positively moderated by employees' political skill. In addition, bootstrapping results also verify the moderating role played by employees' political skill in the indirect relationship between authentic leadership and proactive behavior through core self-evaluations. Theoretical and managerial implications are further discussed in the light of these findings.
基金Joint Fund of Research and Development Program of Henan Province,Grant/Award Number:222301420002National Natural Science Foundation of China,Grant/Award Number:U21A2064Scientific and Technological Innovation Talents in Colleges and Universities in Henan Province,Grant/Award Number:22HASTIT001。
文摘Material composition and structural design are important factors influencing the electromagnetic wave(EMW)absorption performance of materials.To alleviate the impedance mismatch attributed to the high dielectric constant of Ti_(3)C_(2)T_(x)MXene,we have successfully synthesized core‐shell structured SiO_(2)@MXene@MoS_(2)nanospheres.This architecture,comprising SiO_(2) as the core,MXene as the intermediate layer,and MoS_(2) as the outer shell,is achieved through an electrostatic self‐assembly method combined with a hydrothermal process.This complex core‐shell structure not only provides a variety of loss mechanisms that effectively dissipate electromagnetic energy but also prevents self‐aggregation of MXene and MoS_(2) nanosheets.Notably,the synergistic combination of SiO_(2) and MoS_(2) with highly conductive MXene enables the suitable dielectric constant of the composites,ensuring optimal impedance matching.Therefore,the core‐shell structured SiO_(2)@MXene@MoS_(2) nanospheres exhibit excellent EMW absorption performance,featuring a remarkable minimum reflection loss(RL_(min))of−52.11 dB(2.4 mm).It is noteworthy that these nanospheres achieve an ultra‐wide effective absorption bandwidth(EAB)of 6.72 GHz.This work provides a novel approach for designing and synthesizing high‐performance EMW absorbers characterized by“wide bandwidth and strong reflection loss.”
基金Guangzhou Key R&D Program/Plan Unveiled Flagship Project,Grant/Award Number:20220602JBGS02Guangzhou Basic and Applied Basic Research Project,Grant/Award Number:202201011449+3 种基金Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology,Grant/Award Numbers:FC202220,FC202216Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2021A1515010167,2022A1515011196National Natural Science Foundation of China,Grant/Award Numbers:21975292,21978331,22068008,52101186Training Program of the Major Research Plan of the National Natural Science Foundation of China,Grant/Award Number:92061124。
文摘Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.
基金Project supported by the National Natural Science Foundation of China (Nos. 12172339 and 11732005)the Beijing Natural Science Foundation of China (No. 1222006)。
文摘A sandwich plate with a corrugation and auxetic honeycomb hybrid core is constructed,and its sound insulation and optimization are investigated.First,the motion governing equation of the sandwich plate is established by the third-order shear deformation theory(TSDT),and then combined with the fluid-structure coupling conditions,and the sound insulation is solved.The theoretical results are validated by COMSOL simulation results,and the effects of the structural parameter on the sound insulation are analyzed.Finally,the standard genetic algorithm is adopted to optimize the sound insulation of the sandwich plate.
基金supported and funded by the Researchers Supporting Project(Project No.RSPD2024R781),King Saud University,Riyadh,Saudi Arabia。
文摘Identifying deformational mechanisms and associated structures at various scales,ranging from regional-scale structures to microscopic fabric,is crucial for the assessment of tectonic development.Thirty-three samples were taken from the Qazzaz metamorphic core complex to estimate the finite strain for felsic and mafic minerals.These samples included gneisses rocks,monzogranite,and metavolcano-sedimentary rocks for both the Thalbah and Bayda groups.Using the Rf/j and Fry methods,the axial ratios(XZ)range about 2.20 to 7.10 and 1.90 to 9.10,respectively.For various rock units,the strain measurements show moderate to highly deformation.Most of the observed samples show shallow WNW dipping along a N to WNW trend of finite strain(X).The short axes(Z)based to be subvertical foliation related with a subhorizontal foliation.The results demonstrate that contacts generated at semi-brittle to ductile deformation and that the strain of magnitude has the same value for different lithologic units.It concluded that nappe generation in orogens results from pure shear deformation.
基金supported by the National Science Foundation of China(Grant No.42230606)。
文摘Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical core.The NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer time.Recent advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic relationship.In this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the NAS.The NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)model.The forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,respectively.Finally,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic tendency.Corrected by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.
基金the Iranian Nanotechnology Development Committee for their financial supportUniversity of Kashan for supporting this work by Grant No. 1223097/10the micro and nanomechanics laboratory by Grant No. 14022023/5
文摘Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive appearance.However,the inability of controlling and regulating vibrations and destroying them afterward is a challenge to scientists.In this paper,the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms.A five-layer sandwich doubly curved micro-composite shell,comprising two piezoelectric layers for the sensor and actuator,is modeled by the fourth-order shear deformation theory.The core(honeycomb,truss,and corrugated)is analyzed for the bearing of transverse shear forces.The results show that the honeycomb core has a greater effect on the vibrations.When the parameters related to the core and the weight percentage of graphene increase,the frequency increases.The uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency increases.Furthermore,without taking into account the piezoelectric layers,the third-order shear deformation theory(TSDT)and fourth-order shear deformation theory(FOSDT)align closely.However,when the piezoelectric layers are incorporated,these two theories diverge significantly,with the frequencies in the FOSDT being lower than those in the TSDT.
基金Project supported by the National Natural Science Foundation of China (Gant No.11872323)。
文摘Many networks exhibit the core/periphery structure.Core/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral nodes.Core nodes tend to be well-connected,both among themselves and to peripheral nodes,which tend not to be well-connected to other nodes.In this brief report,we propose a new method to detect the core of a network by the centrality of each node.It is discovered that such nodes with non-negative centralities often consist in the core of the networks.The simulation is carried out on different real networks.The results are checked by the objective function.The checked results may show the effectiveness of the simulation results by the centralities of the nodes on the real networks.Furthermore,we discuss the characters of networks with the single core/periphery structure and point out the scope of the application of our method at the end of this paper.
基金funding from the Ministry of Education,Culture,Research,and Technology,Indonesia,through the PDKN Research Grant with Contract No.041/E5/PG.02.00.PL/2023.
文摘Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems that must be resolved.To this end,a drug carrier incorporating natural magnetic cores in a zeolite framework was developed and applied to the loading of curcumin in ethanol solutions.In this system,curcumin is encapsulated in a zeolite Na(ZNA)magnetic core–shell structure(Fe@Si/ZNA),which can be easily synthesized using an in situ method.Synthesis of Fe_(3)O_(4) nanoparticles was carried out from natural materials using a co-precipitation method.Analysis of the prepared magnetic core–shell structures and composites was carried out using vibrating-sample magnetometery,Fourier transform infrared spectroscopy,transmission electron microscopy,and x-ray diffraction.The cumulative loading of curcumin in the ZNA composite with 9%nanoparticles was found to reach 90.70%with a relatively long half-life of 32.49 min.Stability tests of curcumin loading in the composite showed that adding magnetic particles to the zeolite framework also increased the stability of the composite structure.Adsorption kinetics and isotherm studies also found that the system follows the pseudo-second-order and Langmuir isotherm models.
基金Project supported by the National Natural Science Foundation of China(Grant No.11974253).
文摘Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic properties.In this paper,the M-edge spectra of La ions and the M-edge,L-edge,and K-edge spectra of Mn ions in LaMnO3 are calculated by considering both the free-ion multiplet calculation and the crystal field effects.We analyze spectral shapes,identify peak origins,and estimate the oxidation states of La and Mn ions in LaMnO3 theoretically.It is concluded that La ions in LaMnO3 predominantly exist in the trivalent state,while Mn ions exist primarily in the trivalent state with a minor presence of tetravalent ions.Furthermore,the calculated spectra are in better conformity with the experimental spectra when the proportion of Mn3+is 90%and Mn4+is 10%.This article enhances our comprehension of the oxidation states of La and Mn within the crystal and also provides a valuable guidance for spectroscopic investigations of other manganates.
基金This work was supported by the National Key Research Plan(2021YFB2900602).
文摘With the rapid development of low-orbit satellite com-munication networks both domestically and internationally,space-terrestrial integrated networks will become the future development trend.For space and terrestrial networks with limi-ted resources,the utilization efficiency of the entire space-terres-trial integrated networks resources can be affected by the core network indirectly.In order to improve the response efficiency of core networks expansion construction,early warning of the core network elements capacity is necessary.Based on the inte-grated architecture of space and terrestrial network,multidimen-sional factors are considered in this paper,including the number of terminals,login users,and the rules of users’migration during holidays.Using artifical intelligence(AI)technologies,the regis-tered users of the access and mobility management function(AMF),authorization users of the unified data management(UDM),protocol data unit(PDU)sessions of session manage-ment function(SMF)are predicted in combination with the num-ber of login users,the number of terminals.Therefore,the core network elements capacity can be predicted in advance.The proposed method is proven to be effective based on the data from real network.