The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digit...The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digital economy can significantly improve the efficiency of urban energy consumption by virtue of its distinctive characteristics of low pollution and high efficiency.Moreover,empowered by the digital economy,the pace of transformation and upgrading of high-pollution traditional industries has been accelerated.Particularly importantly,the urban energy consumption structure has been optimized and adjusted through the indirect role of intermediate factors.From this perspective,studying the current situation and countermeasures of urban energy consumption under the digital economy holds important practical significance both in theory and practice.This paper first briefly summarizes the relevant literature on the impact of the digital economy on the energy consumption structure;then,it focuses on detailed data to explore the current situation of urban energy consumption under the digital economy model;finally,based on the summary of the current situation,it puts forward practical and feasible suggestions,hoping to provide a decision-making basis for the implementation of policies in different types of cities and offer innovative ideas for promoting the high-quality development of urban energy systems.展开更多
With the widespread use of social media,the propagation of health-related rumors has become a significant public health threat.Existing methods for detecting health rumors predominantly rely on external knowledge or p...With the widespread use of social media,the propagation of health-related rumors has become a significant public health threat.Existing methods for detecting health rumors predominantly rely on external knowledge or propagation structures,with only a few recent approaches attempting causal inference;however,these have not yet effectively integrated causal discovery with domain-specific knowledge graphs for detecting health rumors.In this study,we found that the combined use of causal discovery and domain-specific knowledge graphs can effectively identify implicit pseudo-causal logic embedded within texts,holding significant potential for health rumor detection.To this end,we propose CKDG—a dual-graph fusion framework based on causal logic and medical knowledge graphs.CKDG constructs a weighted causal graph to capture the implicit causal relationships in the text and introduces a medical knowledge graph to verify semantic consistency,thereby enhancing the ability to identify the misuse of professional terminology and pseudoscientific claims.In experiments conducted on a dataset comprising 8430 health rumors,CKDG achieved an accuracy of 91.28%and an F1 score of 90.38%,representing improvements of 5.11%and 3.29%over the best baseline,respectively.Our results indicate that the integrated use of causal discovery and domainspecific knowledge graphs offers significant advantages for health rumor detection systems.This method not only improves detection performance but also enhances the transparency and credibility of model decisions by tracing causal chains and sources of knowledge conflicts.We anticipate that this work will provide key technological support for the development of trustworthy health-information filtering systems,thereby improving the reliability of public health information on social media.展开更多
The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer wa...The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer was in situ constructed on the surface of NaCrO_(2)by controlling the excess ratio of sodium source.The structure,morphology,valence and electrochemical performance of the Cr_(2)O_(3)-coated NaCrO_(2)were characterized.The results indicate that the Cr_(2)O_(3)coating layer does not alter the crystal structure and morphology of NaCrO_(2),but effectively suppresses the side reactions between NaCrO_(2)and electrolyte,and improves the surface/interfacial stability of NaCrO_(2)material.The Cr_(2)O_(3)-coated NaCrO_(2)exhibits improved electrochemical performance with a capacity retention of 66.4%after 500 cycles at 10C.展开更多
In this work,several HZSM-5 catalysts with different Si/Al ratios treated with acids are selected as catalysts and used for hydration of cyclohexene to cyclohexanol.The results indicated that HZSM-5(Si/Al=38)modified ...In this work,several HZSM-5 catalysts with different Si/Al ratios treated with acids are selected as catalysts and used for hydration of cyclohexene to cyclohexanol.The results indicated that HZSM-5(Si/Al=38)modified with 4 mol·L^(-1) nitric acid was selected as an efficient catalyst for improving the hydration efficiency of cyclohexene.Furthermore,the microstructures and properties of fresh,used and regenerated acid-modified catalysts have been characterized by X-ray diffraction,scanning electron microscopy,nitrogen adsorption/desorption isotherm,Fourier transform infrared,thermal gravimetric analyzer,ammonia temperature programmed desorption and pyridine adsorbs Fourier transform infrared.The characterization results indicated that the total surface areas and pore volume of HZSM-5 zeolite increased after nitric acid treatment due to the formation of mesoporous structure.This benefits the diffusion rate of reactants and products,which improves the hydration efficiency and stability of the catalyst.Under the catalysis of HZSM-5,the conversion of cyclohexene was found to be 9.0%.However,treatment of HZSM-5 with nitric acid enhanced the conversion of cyclohexene to 12.2%,achieving a selectivity of 99.7%for cyclohexanol under optimal reaction conditions.This work affords a mild and efficient approach for improving the hydration efficiency and has potential industrial application value.展开更多
Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge....Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.展开更多
This study primarily investigates the effect of CeO_(2)content on the microstructure and mechanical properties of ZK60 Mg alloy.The results indicate that CeO_(2)can be reduced by Mg to elemental Ce,predominantly in th...This study primarily investigates the effect of CeO_(2)content on the microstructure and mechanical properties of ZK60 Mg alloy.The results indicate that CeO_(2)can be reduced by Mg to elemental Ce,predominantly in the form of the Mg-Zn-Ce phase.The addition of CeO_(2)notably refines the grain size of as-cast ZK60 Mg alloy,with the Mg-Zn-Ce phase primarily distributed along grain boundaries.After extrusion,grain size increases and then decreases with increasing CeO_(2)content,while the dynamic recrystallization(DRX)fraction gradually reduces.This behavior is chiefly attributed to the hindrance of the DRX process by a high density of second phases and the restriction of recrystallized grains growth by fine particles.The basal texture intensity increases progressively with the addition of CeO_(2).As the CeO_(2)content rises,the yield strength(YS)and elongation(EL)of the alloys show significant improvement.The increase in YS is mainly due to the combined effects of grain refinement strengthening and dispersion strengthening.In contrast,the enhanced EL is closely related to the heterogeneous structure of the grains.Notably,the ZK60-1.2CeO_(2)alloy exhibits the ultimate tensile strength,YS and EL of 274 MPa,160 MPa and 17.3%,respectively.展开更多
By using error correction model, I conduct co-integration analysis on the research of the relationship between the per capita practical consumption and per capita practical disposable income of urban residents in Huna...By using error correction model, I conduct co-integration analysis on the research of the relationship between the per capita practical consumption and per capita practical disposable income of urban residents in Hunan Province from 1978 to 2009. The results show that there is a co-integration relationship between the per capita practical consumption and the practical per capita disposable income of urban residents, and based on these, the corresponding error correction model is established. Finally, corresponding countermeasures and suggestions are put forward as follows: broaden the income channel of urban residents; create goods consuming environment; perfect socialist security system.展开更多
In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and ...In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and subsequent annealing.Due to the identical metal core,these nanoparticles exhibite a similar permeability,but significantly varying permittivity depending on how much C shells have been graphi-tized.It was discovered that proper graphitization of Fe-C nanoparticles annealed at 1350 ℃ can pro-duce excellent microwave absorption(MA),decent dielectric loss tangent in high frequency region,and moderately strong dielectric loss and attenuation properties.Furthermore,the threshold value of 1/ω is discovered to be a crucial parameter in the theoretical analysis of nonlinear behavior of polarization loss,and thus MA performance of the nanoparticles.This research offers a useful method for creating metal-C nanoparticles with various levels of C shell graphitization.It also provides a clear answer to the crucial question of how the level of C shell graphitization affects the MA performance of metal-C nanoparticles.These results may serve as a reference for the development and mechanism analysis of highly effective metal-C based absorbers.展开更多
Based on literature review,according to relevant consumption data in Hunan Statistical Yearbook and China Statistical Yearbook during1978-2009,the thesis selects three indexes involving the average income per rural re...Based on literature review,according to relevant consumption data in Hunan Statistical Yearbook and China Statistical Yearbook during1978-2009,the thesis selects three indexes involving the average income per rural resident,per capita living expenses of rural residents and percapita savings to conduct the unit root and co-integration test on the consumption and net income per rural residents in Hunan Province by adoptingthe generalized difference method and EVIEWS6.0,then according to the Modigliani Hypothesis of Consumption,Duesenberry Hypothesis of Con-sumption and Keynes Absolute Income Hypothesis,the thesis makes a fitting of Hunan consumption function model,aiming to find out the consump-tion function model suitable to Hunan Province.The results show that,Keynesian consumption function based on Absolute Income Hypothesis pas-ses the statistical test and econometric test,while the consumption function model based on Relative Income Hypothesis and that based on Life Cy-cle Hypothesis do not,which proves that the consumption function model based on Absolute Income Hypothesis is better suited for describing the re-lations between rural consumption and income in Hunan Province.Taking into account the low marginal propensity of consumption of the rural resi-dents in Hunan Province,the thesis proposes to expand consumption demand of rural residents:firstly,developing characteristic economy and im-proving the income level of rural residents;secondly,perfecting the social security system in rural areas and maintaining the consumption confi-dence of rural residents;thirdly,ameliorating the circulation system.展开更多
The identification of indoor harmful gases is imperative due to their significant threats to human health and safety.To achieve accurate identification,an effective strategy of constructing a sensor array combined wit...The identification of indoor harmful gases is imperative due to their significant threats to human health and safety.To achieve accurate identification,an effective strategy of constructing a sensor array combined with the pattern recognition algorithm is employed.Carbon-based thin-film transistors are selected as the sensor array unit,with semiconductor carbon nanotubes(CNTs)within the TFT channels modified with different metals(Au,Cu and Ti)for selective responses to NH_(3),H_(2)S and HCHO,respectively.For accurate gas species identification,an identification mode that combines linear discriminant analysis algorithms and logistic regression classifier is developed.The test results demonstrate that by preprocessing the sensor array’s sensing data with the LDA algorithm and subsequently employing the LR classifier for identification,a 100%recognition rate can be achieved for three target gases(NH3,H2S and HCHO).This work provides significant guidance for future applications of chip-level gas sensors in the realms of the Internet of Things and Artificial Intelligence.展开更多
To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research objec...To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research object to further elucidate the underlying mechanism of caged dynamics from multiple perspectives,including the cage's lifetime,atomic local environment,and atomic potential energy.The results reveal that Si atoms exhibit a pronounced cage effect due to the hindrance of Pd atoms,resulting in an anomalous peak in the non-Gaussian parameters.An in-depth investigation was conducted on the caged dynamics differences between fast and slow Si atoms.In comparison to fast Si atoms,slow Si atoms were surrounded by more Pd atoms and occupied lower potential energy states,resulting in smaller diffusion displacements for the slow Si atoms.Concurrently,slow Si atoms tend to be in the centers of smaller clusters with coordination numbers of 9 and 10.During the isothermal relaxation process,clusters with coordination numbers 9 and 10 have longer lifetimes,suggesting that the escape of slow Si atoms from their cages is more challenging.The findings mentioned above hold significant implications for understanding the caged dynamics.展开更多
Different amounts of La_(2)O_(3)were added to ZK60 alloy to observe the changes in microstructure and mechanical properties of ZK60-XLa_(2)O_(3)(X=0,0.2 wt%,0.5 wt%)composites.Our findings reveal that within the as-ca...Different amounts of La_(2)O_(3)were added to ZK60 alloy to observe the changes in microstructure and mechanical properties of ZK60-XLa_(2)O_(3)(X=0,0.2 wt%,0.5 wt%)composites.Our findings reveal that within the as-cast ZK60 alloy,the Mg-Zn binary phase is manifested as rod-shaped precipitates,exhibiting a dispersed distribution predominantly along the grain boundary regions.With the increase of La_(2)O_(3)addition,the rod-like Mg-Zn binary phases are gradually replaced by Mg-Zn-La ternary phases,and these Mg-Zn-La ternary phases are semi-continuously distributed around the grain boundaries.Both ZK602 and ZK605 alloys result in a corresponding improvement in ductility after extrusion.It is noteworthy that the ductility of the as-extruded ZK605 alloy is increased by 59.4%compared to ZK60 at the expense of a reduction of only 3.9%in yield strength.Taken together,the significant increase in ductility of ZK605 is mainly due to the weakening of the basal texture,which is weakened by the redox reaction of La_(2)O_(3)with the a-Mg matrix,generating the La element.The decrease in yield strength of ZK605 in the extruded state is closely related to the observed grain coarsening phenomenon and the basal texture weakening.At the same time,the ultimate tensile strength of ZK605 shows a slight increase,which is mainly due to the second phase strengthening.The Mg-Zn-La ternary phase exhibits a notably hard character,and it is evident that the distribution of this phase becomes progressively denser as the La_(2)O_(3)content increases.展开更多
In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furn...In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.展开更多
Political instability has increased drastically in Pakistan during the last few decades.This may intensify the fear of investors and eventually affect investment decisions.Therefore,the stock market’s reaction to pol...Political instability has increased drastically in Pakistan during the last few decades.This may intensify the fear of investors and eventually affect investment decisions.Therefore,the stock market’s reaction to political stability must be explored and appropriate policy measures should be prescribed.This paper examines the effect of political stability on stock market returns and volatility using time series data from Pakistan for the period from January 02,2004,to May 31,2018.The study uses the Generalized Autoregressive Conditional Heteroskedastic(GARCH)and Exponential Generalized Autoregressive Conditional Heteroskedastic(EGARCH)models to achieve the main objectives.The findings of the GARCH and EGARCH models confirm that political stability has a positive and significant influence on both stock market returns and volatility in Pakistan.In addition,the EGARCH findings indicate that negative shock(political instability)creates more volatility in the stock market than positive shock(political stability).The results of this study reveal that financial market investors are affected more by political instability.In conclusion,this study suggests that political stability is an essential factor affecting financial market volatility,and it leads to stable financial markets.It also emphasizes that political instability needs to be resolved to achieve stable financial markets.展开更多
High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has c...High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.展开更多
The tunable dielectric and magnetic properties of high entropy alloy(HEA)nanoparticles have attracted considerable interest in realizing optimal impedance matching and microwave absorption performance.However,the comp...The tunable dielectric and magnetic properties of high entropy alloy(HEA)nanoparticles have attracted considerable interest in realizing optimal impedance matching and microwave absorption performance.However,the compositional engineering of HEA nanoparticles in regulating their dielectric-magnetic balance to achieve high-performance microwave absorption remains challenging.Herein,a vaporphase synthesis method is employed to prepare C-coated CoNiFeCuCr_(x)HEA nanoparticles with tunable Cr content.The prepared HEA nanoparticles,with a size of less than 10 nm,exhibited typical soft ferromagnetic characteristics.In conjunction with the additional contributions of interfacial polarization,graphitization of the C-shell,and tunable Cr content to the regulation of electromagnetic parameters,the C-coated CoNiFeCuCr_(0.5) nanoparticles exhibit a minimum reflection loss(RL_(min))of−63.9 dB and an effective absorption bandwidth(EAB)of 5.52 GHz,with an optimal thickness of 2.1 mm.Moreover,by employing a gradient three-layer architectural design,the EAB can be further extended to 12.22 GHz.Simultaneously,the simulated radar cross-section(RCS)results highlight its exceptional radar stealth performance,with RCS values remaining below−20 dBm^(2) across a wide angular range of−85°to 85°.This study offers valuable perspectives on designing high-performance HEA-based electromagnetic wave absorbing materials,achieving outstanding microwave absorption and radar stealth capabilities through careful compositional engineering.展开更多
Physical unclonable functions(PUFs)offer a promising defensive measure against the escalating challenges posed by the increasingly rampant counterfeit products.Conventional PUF materials with a singular physical prope...Physical unclonable functions(PUFs)offer a promising defensive measure against the escalating challenges posed by the increasingly rampant counterfeit products.Conventional PUF materials with a singular physical property encounter limitations in encoding flexibility and capacity.Here,we propose a dual-color center diamond-based PUF(D-PUF)ink that exploits four diverse optical characteristics of dual-color center in diamond to design a concealable multi-level cryptographic authentication protocol.Through simple writing,stamping,or spraying,intricate covert random patterns can be directly generated on the objects,which are imperceptible under visible light.When challenged by a 532 nm laser,the D-PUF exhibits four distinct optical responses,including Raman,zero phonon line(ZPL)of germanium vacancies(GeV),ZPL of silicon vacancies(SiV),and the intensity ratios of these ZPLs.These responses were harvested simultaneously to construct the four-level separate encodable matrices.Furthermore,M-ary encoding algorithms were implemented to encrypt PUFs with flexibility.The resulting multi-level PUF system attains notable uniqueness,repeatability,extensive encoding capacity(>1048164/(100 pixels)2),and ultra-high information entropy(6 bits/pixel).This study inspires designing new generations of multi-level PUFs with enhanced coding flexibility and holds significant promise for applications in print security.展开更多
Bridges may suffer from large-amplitude vibrations due to strong winds,earthquakes,human-induced loads,and vehicle-induced dynamic loads.Metallic dampers employed the energy dissipation from the hysteretic behavior of...Bridges may suffer from large-amplitude vibrations due to strong winds,earthquakes,human-induced loads,and vehicle-induced dynamic loads.Metallic dampers employed the energy dissipation from the hysteretic behavior of metal materials are among the most effective methods to mitigate bridge vibrations.This paper reviews the development and application of metallic-yielding dampers for the vibration control of bridges.Various theoretical models for metallic damper analyses are reviewed.Different yielding mechanisms and manufacturing materials of metallic dampers are discussed.Finally,the recent progress and application of bridge engineering are summarized.It can be concluded that each section of the torsion-type metallic damper exhibits a uniform stress state and undergoes plastic deformation simultaneously.Therefore,the damper has a strong energy dissipation capacity.Additionally,self-centering metallic dampers can automatically recover to their initial position after suffering an earthquake.Combined metallic dampers can take advantage of different types of dampers,thereby enhancing damping performance.Finally,these dampers will significantly enhance the seismic performance and overall safety of bridge structures.Future research will likely focus on hybrid systems that combine metallic dampers with other energy consumption mechanisms to further improve adaptability and energy dissipation,advancing the resilience and safety of bridge structures.展开更多
P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The re...P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The results show that the sample obtained at 900℃ is pure P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) phase with good crystallization,which consists of hexagon plate-shaped particles with the size and thickness of 2−4μm and 200−400 nm,respectively.The sample exhibits an initial specific discharge capacity of 243 mA·h/g at a current density of 26 mA/g with good cycling stability.The high specific capacity indicates that P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) is a promising cathode material for sodiumion batteries.展开更多
Spherical LiNi0.8Co0.15Al0.05O2 OOH precursor prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.5Co0.15Al0.05O2. The obtained LiNi0.8Co0.15Al0.05O2 materials showed excellent e...Spherical LiNi0.8Co0.15Al0.05O2 OOH precursor prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.5Co0.15Al0.05O2. The obtained LiNi0.8Co0.15Al0.05O2 materials showed excellent electrochemical performance, with an initial discharge capacity of 193.5 mAh/g and capacity retention of 95.1% after 50 cycles when cycled at 0.2 C rate between 2.8 and 4.3 V.展开更多
文摘The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digital economy can significantly improve the efficiency of urban energy consumption by virtue of its distinctive characteristics of low pollution and high efficiency.Moreover,empowered by the digital economy,the pace of transformation and upgrading of high-pollution traditional industries has been accelerated.Particularly importantly,the urban energy consumption structure has been optimized and adjusted through the indirect role of intermediate factors.From this perspective,studying the current situation and countermeasures of urban energy consumption under the digital economy holds important practical significance both in theory and practice.This paper first briefly summarizes the relevant literature on the impact of the digital economy on the energy consumption structure;then,it focuses on detailed data to explore the current situation of urban energy consumption under the digital economy model;finally,based on the summary of the current situation,it puts forward practical and feasible suggestions,hoping to provide a decision-making basis for the implementation of policies in different types of cities and offer innovative ideas for promoting the high-quality development of urban energy systems.
基金funded by the Hunan Provincial Natural Science Foundation of China(Grant No.2025JJ70105)the Hunan Provincial College Students’Innovation and Entrepreneurship Training Program(Project No.S202411342056)The article processing charge(APC)was funded by the Project No.2025JJ70105.
文摘With the widespread use of social media,the propagation of health-related rumors has become a significant public health threat.Existing methods for detecting health rumors predominantly rely on external knowledge or propagation structures,with only a few recent approaches attempting causal inference;however,these have not yet effectively integrated causal discovery with domain-specific knowledge graphs for detecting health rumors.In this study,we found that the combined use of causal discovery and domain-specific knowledge graphs can effectively identify implicit pseudo-causal logic embedded within texts,holding significant potential for health rumor detection.To this end,we propose CKDG—a dual-graph fusion framework based on causal logic and medical knowledge graphs.CKDG constructs a weighted causal graph to capture the implicit causal relationships in the text and introduces a medical knowledge graph to verify semantic consistency,thereby enhancing the ability to identify the misuse of professional terminology and pseudoscientific claims.In experiments conducted on a dataset comprising 8430 health rumors,CKDG achieved an accuracy of 91.28%and an F1 score of 90.38%,representing improvements of 5.11%and 3.29%over the best baseline,respectively.Our results indicate that the integrated use of causal discovery and domainspecific knowledge graphs offers significant advantages for health rumor detection systems.This method not only improves detection performance but also enhances the transparency and credibility of model decisions by tracing causal chains and sources of knowledge conflicts.We anticipate that this work will provide key technological support for the development of trustworthy health-information filtering systems,thereby improving the reliability of public health information on social media.
基金supported by the Scientific Research Fund of Hunan Provincial Education Department,China(No.22B0741)。
文摘The electrochemical performance of layered O3-type NaCrO_(2)cathode material is significantly affected by the side reactions between NaCrO_(2)and electrolyte during sodium storage.A uniform Cr_(2)O_(3)coating layer was in situ constructed on the surface of NaCrO_(2)by controlling the excess ratio of sodium source.The structure,morphology,valence and electrochemical performance of the Cr_(2)O_(3)-coated NaCrO_(2)were characterized.The results indicate that the Cr_(2)O_(3)coating layer does not alter the crystal structure and morphology of NaCrO_(2),but effectively suppresses the side reactions between NaCrO_(2)and electrolyte,and improves the surface/interfacial stability of NaCrO_(2)material.The Cr_(2)O_(3)-coated NaCrO_(2)exhibits improved electrochemical performance with a capacity retention of 66.4%after 500 cycles at 10C.
基金financial support by the National Natural Science Foundation of China(22378339)Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization.
文摘In this work,several HZSM-5 catalysts with different Si/Al ratios treated with acids are selected as catalysts and used for hydration of cyclohexene to cyclohexanol.The results indicated that HZSM-5(Si/Al=38)modified with 4 mol·L^(-1) nitric acid was selected as an efficient catalyst for improving the hydration efficiency of cyclohexene.Furthermore,the microstructures and properties of fresh,used and regenerated acid-modified catalysts have been characterized by X-ray diffraction,scanning electron microscopy,nitrogen adsorption/desorption isotherm,Fourier transform infrared,thermal gravimetric analyzer,ammonia temperature programmed desorption and pyridine adsorbs Fourier transform infrared.The characterization results indicated that the total surface areas and pore volume of HZSM-5 zeolite increased after nitric acid treatment due to the formation of mesoporous structure.This benefits the diffusion rate of reactants and products,which improves the hydration efficiency and stability of the catalyst.Under the catalysis of HZSM-5,the conversion of cyclohexene was found to be 9.0%.However,treatment of HZSM-5 with nitric acid enhanced the conversion of cyclohexene to 12.2%,achieving a selectivity of 99.7%for cyclohexanol under optimal reaction conditions.This work affords a mild and efficient approach for improving the hydration efficiency and has potential industrial application value.
基金funding support from Guiding Project of Scientific Research Plan of Education Department of Hubei Province and Wuhan Textile University School Fund(B)(k24016).
文摘Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.
基金the financial supports from the National Natural Science Foundation of China(Nos.52171099,51301025,51140001)the Education Department of Hunan Province of China(No.22A0240)the State Key Laboratory of Disaster Prevention&Reduction for Power Grid,Changsha University of Science&Technology.
文摘This study primarily investigates the effect of CeO_(2)content on the microstructure and mechanical properties of ZK60 Mg alloy.The results indicate that CeO_(2)can be reduced by Mg to elemental Ce,predominantly in the form of the Mg-Zn-Ce phase.The addition of CeO_(2)notably refines the grain size of as-cast ZK60 Mg alloy,with the Mg-Zn-Ce phase primarily distributed along grain boundaries.After extrusion,grain size increases and then decreases with increasing CeO_(2)content,while the dynamic recrystallization(DRX)fraction gradually reduces.This behavior is chiefly attributed to the hindrance of the DRX process by a high density of second phases and the restriction of recrystallized grains growth by fine particles.The basal texture intensity increases progressively with the addition of CeO_(2).As the CeO_(2)content rises,the yield strength(YS)and elongation(EL)of the alloys show significant improvement.The increase in YS is mainly due to the combined effects of grain refinement strengthening and dispersion strengthening.In contrast,the enhanced EL is closely related to the heterogeneous structure of the grains.Notably,the ZK60-1.2CeO_(2)alloy exhibits the ultimate tensile strength,YS and EL of 274 MPa,160 MPa and 17.3%,respectively.
基金Supported by the Scientific Research Subject of Department of Education in Hunan Province(10C0556)
文摘By using error correction model, I conduct co-integration analysis on the research of the relationship between the per capita practical consumption and per capita practical disposable income of urban residents in Hunan Province from 1978 to 2009. The results show that there is a co-integration relationship between the per capita practical consumption and the practical per capita disposable income of urban residents, and based on these, the corresponding error correction model is established. Finally, corresponding countermeasures and suggestions are put forward as follows: broaden the income channel of urban residents; create goods consuming environment; perfect socialist security system.
基金Hunan Provincial Natural Science Foundation of China(Nos.2022JJ40121,2021JJ40153 and 2021JJ50108)Scientific Research Fund of Hunan Provincial Education Department(Nos.21B0657,22A0518).
文摘In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and subsequent annealing.Due to the identical metal core,these nanoparticles exhibite a similar permeability,but significantly varying permittivity depending on how much C shells have been graphi-tized.It was discovered that proper graphitization of Fe-C nanoparticles annealed at 1350 ℃ can pro-duce excellent microwave absorption(MA),decent dielectric loss tangent in high frequency region,and moderately strong dielectric loss and attenuation properties.Furthermore,the threshold value of 1/ω is discovered to be a crucial parameter in the theoretical analysis of nonlinear behavior of polarization loss,and thus MA performance of the nanoparticles.This research offers a useful method for creating metal-C nanoparticles with various levels of C shell graphitization.It also provides a clear answer to the crucial question of how the level of C shell graphitization affects the MA performance of metal-C nanoparticles.These results may serve as a reference for the development and mechanism analysis of highly effective metal-C based absorbers.
文摘Based on literature review,according to relevant consumption data in Hunan Statistical Yearbook and China Statistical Yearbook during1978-2009,the thesis selects three indexes involving the average income per rural resident,per capita living expenses of rural residents and percapita savings to conduct the unit root and co-integration test on the consumption and net income per rural residents in Hunan Province by adoptingthe generalized difference method and EVIEWS6.0,then according to the Modigliani Hypothesis of Consumption,Duesenberry Hypothesis of Con-sumption and Keynes Absolute Income Hypothesis,the thesis makes a fitting of Hunan consumption function model,aiming to find out the consump-tion function model suitable to Hunan Province.The results show that,Keynesian consumption function based on Absolute Income Hypothesis pas-ses the statistical test and econometric test,while the consumption function model based on Relative Income Hypothesis and that based on Life Cy-cle Hypothesis do not,which proves that the consumption function model based on Absolute Income Hypothesis is better suited for describing the re-lations between rural consumption and income in Hunan Province.Taking into account the low marginal propensity of consumption of the rural resi-dents in Hunan Province,the thesis proposes to expand consumption demand of rural residents:firstly,developing characteristic economy and im-proving the income level of rural residents;secondly,perfecting the social security system in rural areas and maintaining the consumption confi-dence of rural residents;thirdly,ameliorating the circulation system.
基金financially supported by the National Natural Science Foundation of China(Nos.62071410 and62101477)Hunan Provincial Natural Science Foundation of China(Nos.2021JJ40542 and 2023JJ30596)the science and technology innovation Program of Hunan Province(No.2023RC3133)。
文摘The identification of indoor harmful gases is imperative due to their significant threats to human health and safety.To achieve accurate identification,an effective strategy of constructing a sensor array combined with the pattern recognition algorithm is employed.Carbon-based thin-film transistors are selected as the sensor array unit,with semiconductor carbon nanotubes(CNTs)within the TFT channels modified with different metals(Au,Cu and Ti)for selective responses to NH_(3),H_(2)S and HCHO,respectively.For accurate gas species identification,an identification mode that combines linear discriminant analysis algorithms and logistic regression classifier is developed.The test results demonstrate that by preprocessing the sensor array’s sensing data with the LDA algorithm and subsequently employing the LR classifier for identification,a 100%recognition rate can be achieved for three target gases(NH3,H2S and HCHO).This work provides significant guidance for future applications of chip-level gas sensors in the realms of the Internet of Things and Artificial Intelligence.
基金Project supported by the National Natural Science Foundation of China (Grant No.51701071)the Natural Science Foundation of Hunan Province,China (Grant Nos.2022JJ50115 and 2021JJ30179)the Research Foundation of the Education Bureau of Hunan Province,China (Grant No.22A0522)。
文摘To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research object to further elucidate the underlying mechanism of caged dynamics from multiple perspectives,including the cage's lifetime,atomic local environment,and atomic potential energy.The results reveal that Si atoms exhibit a pronounced cage effect due to the hindrance of Pd atoms,resulting in an anomalous peak in the non-Gaussian parameters.An in-depth investigation was conducted on the caged dynamics differences between fast and slow Si atoms.In comparison to fast Si atoms,slow Si atoms were surrounded by more Pd atoms and occupied lower potential energy states,resulting in smaller diffusion displacements for the slow Si atoms.Concurrently,slow Si atoms tend to be in the centers of smaller clusters with coordination numbers of 9 and 10.During the isothermal relaxation process,clusters with coordination numbers 9 and 10 have longer lifetimes,suggesting that the escape of slow Si atoms from their cages is more challenging.The findings mentioned above hold significant implications for understanding the caged dynamics.
基金Project supported by the National Natural Science Foundation of China(52171099,51301025,51140001)the Education Department of Hunan Province of China(22A0240)。
文摘Different amounts of La_(2)O_(3)were added to ZK60 alloy to observe the changes in microstructure and mechanical properties of ZK60-XLa_(2)O_(3)(X=0,0.2 wt%,0.5 wt%)composites.Our findings reveal that within the as-cast ZK60 alloy,the Mg-Zn binary phase is manifested as rod-shaped precipitates,exhibiting a dispersed distribution predominantly along the grain boundary regions.With the increase of La_(2)O_(3)addition,the rod-like Mg-Zn binary phases are gradually replaced by Mg-Zn-La ternary phases,and these Mg-Zn-La ternary phases are semi-continuously distributed around the grain boundaries.Both ZK602 and ZK605 alloys result in a corresponding improvement in ductility after extrusion.It is noteworthy that the ductility of the as-extruded ZK605 alloy is increased by 59.4%compared to ZK60 at the expense of a reduction of only 3.9%in yield strength.Taken together,the significant increase in ductility of ZK605 is mainly due to the weakening of the basal texture,which is weakened by the redox reaction of La_(2)O_(3)with the a-Mg matrix,generating the La element.The decrease in yield strength of ZK605 in the extruded state is closely related to the observed grain coarsening phenomenon and the basal texture weakening.At the same time,the ultimate tensile strength of ZK605 shows a slight increase,which is mainly due to the second phase strengthening.The Mg-Zn-La ternary phase exhibits a notably hard character,and it is evident that the distribution of this phase becomes progressively denser as the La_(2)O_(3)content increases.
基金the Financial Supported by Hunan Provincial Natural Science Foundation of China(No.2023JJ50224)2021–2022 Hunan Province Enterprise Science and Technology Commissioner Program Project(No.2021GK5046)+1 种基金Hunan Provincial Natural Science Foundation of China(No.2022JJ50013)Hunan Provincial Natural Science Foundation of China(No.2022JJ50041).
文摘In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.
文摘Political instability has increased drastically in Pakistan during the last few decades.This may intensify the fear of investors and eventually affect investment decisions.Therefore,the stock market’s reaction to political stability must be explored and appropriate policy measures should be prescribed.This paper examines the effect of political stability on stock market returns and volatility using time series data from Pakistan for the period from January 02,2004,to May 31,2018.The study uses the Generalized Autoregressive Conditional Heteroskedastic(GARCH)and Exponential Generalized Autoregressive Conditional Heteroskedastic(EGARCH)models to achieve the main objectives.The findings of the GARCH and EGARCH models confirm that political stability has a positive and significant influence on both stock market returns and volatility in Pakistan.In addition,the EGARCH findings indicate that negative shock(political instability)creates more volatility in the stock market than positive shock(political stability).The results of this study reveal that financial market investors are affected more by political instability.In conclusion,this study suggests that political stability is an essential factor affecting financial market volatility,and it leads to stable financial markets.It also emphasizes that political instability needs to be resolved to achieve stable financial markets.
基金supported by the National Natural Science Foundation of China(22378431,52004338,51622406,21673298)Hunan Provincial Natural Science Foundation(2023JJ40210,2022JJ20075)+3 种基金the Science and Technology Innovation Program of Hunan Province(2023RC3259)the Key R&D plan of Hunan Province(2024JK2096)Scientifc Research Fund of Hunan Provincial Education Department(23B0699)Central South University Innovation-Driven Research Programme(2023CXQD008).
文摘High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.
基金supported by the Hunan Provincial Natural Science Foundation of China(2025JJ50021,2025JJ50003)National Natural Science Foundation of China(12072111,11674399)Changsha Municipal Natural Science Foundation(kq2402196)。
文摘The tunable dielectric and magnetic properties of high entropy alloy(HEA)nanoparticles have attracted considerable interest in realizing optimal impedance matching and microwave absorption performance.However,the compositional engineering of HEA nanoparticles in regulating their dielectric-magnetic balance to achieve high-performance microwave absorption remains challenging.Herein,a vaporphase synthesis method is employed to prepare C-coated CoNiFeCuCr_(x)HEA nanoparticles with tunable Cr content.The prepared HEA nanoparticles,with a size of less than 10 nm,exhibited typical soft ferromagnetic characteristics.In conjunction with the additional contributions of interfacial polarization,graphitization of the C-shell,and tunable Cr content to the regulation of electromagnetic parameters,the C-coated CoNiFeCuCr_(0.5) nanoparticles exhibit a minimum reflection loss(RL_(min))of−63.9 dB and an effective absorption bandwidth(EAB)of 5.52 GHz,with an optimal thickness of 2.1 mm.Moreover,by employing a gradient three-layer architectural design,the EAB can be further extended to 12.22 GHz.Simultaneously,the simulated radar cross-section(RCS)results highlight its exceptional radar stealth performance,with RCS values remaining below−20 dBm^(2) across a wide angular range of−85°to 85°.This study offers valuable perspectives on designing high-performance HEA-based electromagnetic wave absorbing materials,achieving outstanding microwave absorption and radar stealth capabilities through careful compositional engineering.
基金the support of the National Key Research and Development Program of China(No.2022YFB3608604)the National Natural Science Foundation of China(Nos.U22A2077 and U21A2070)+5 种基金Shandong Provincial Natural Science Foundation(No.ZR2022MH280)Medical Science and Technology Project of Shandong Province(No.202307020692)Natural Science Foundation of Henan(Nos.212300410020 and 222300420297)Science and Technology Major Project of Henan Province(No.221100230300)the Fundamental Research Fund of Henan Academy of Sciences(No.20250627005)Henan Postdoctoral Foundation(No.202101007).
文摘Physical unclonable functions(PUFs)offer a promising defensive measure against the escalating challenges posed by the increasingly rampant counterfeit products.Conventional PUF materials with a singular physical property encounter limitations in encoding flexibility and capacity.Here,we propose a dual-color center diamond-based PUF(D-PUF)ink that exploits four diverse optical characteristics of dual-color center in diamond to design a concealable multi-level cryptographic authentication protocol.Through simple writing,stamping,or spraying,intricate covert random patterns can be directly generated on the objects,which are imperceptible under visible light.When challenged by a 532 nm laser,the D-PUF exhibits four distinct optical responses,including Raman,zero phonon line(ZPL)of germanium vacancies(GeV),ZPL of silicon vacancies(SiV),and the intensity ratios of these ZPLs.These responses were harvested simultaneously to construct the four-level separate encodable matrices.Furthermore,M-ary encoding algorithms were implemented to encrypt PUFs with flexibility.The resulting multi-level PUF system attains notable uniqueness,repeatability,extensive encoding capacity(>1048164/(100 pixels)2),and ultra-high information entropy(6 bits/pixel).This study inspires designing new generations of multi-level PUFs with enhanced coding flexibility and holds significant promise for applications in print security.
基金supported by the National Natural Science Foundation of China(Grant Nos.52278304,52025082)the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC3090)the Changsha Outstanding Innovative Youth Culturing Program(Grant No.kq2209009)。
文摘Bridges may suffer from large-amplitude vibrations due to strong winds,earthquakes,human-induced loads,and vehicle-induced dynamic loads.Metallic dampers employed the energy dissipation from the hysteretic behavior of metal materials are among the most effective methods to mitigate bridge vibrations.This paper reviews the development and application of metallic-yielding dampers for the vibration control of bridges.Various theoretical models for metallic damper analyses are reviewed.Different yielding mechanisms and manufacturing materials of metallic dampers are discussed.Finally,the recent progress and application of bridge engineering are summarized.It can be concluded that each section of the torsion-type metallic damper exhibits a uniform stress state and undergoes plastic deformation simultaneously.Therefore,the damper has a strong energy dissipation capacity.Additionally,self-centering metallic dampers can automatically recover to their initial position after suffering an earthquake.Combined metallic dampers can take advantage of different types of dampers,thereby enhancing damping performance.Finally,these dampers will significantly enhance the seismic performance and overall safety of bridge structures.Future research will likely focus on hybrid systems that combine metallic dampers with other energy consumption mechanisms to further improve adaptability and energy dissipation,advancing the resilience and safety of bridge structures.
基金the financial supports from the Natural Science Foundation of Hunan Province,China(No.2020JJ5102)the Scientific Research Fund of Hunan Provincial Education Department,China(No.19A111).
文摘P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The results show that the sample obtained at 900℃ is pure P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) phase with good crystallization,which consists of hexagon plate-shaped particles with the size and thickness of 2−4μm and 200−400 nm,respectively.The sample exhibits an initial specific discharge capacity of 243 mA·h/g at a current density of 26 mA/g with good cycling stability.The high specific capacity indicates that P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) is a promising cathode material for sodiumion batteries.
基金supported by National Natural Science Foundation of China(No.50604018)National Key Technology R&D Program of China(No.2007BAE12B01)
文摘Spherical LiNi0.8Co0.15Al0.05O2 OOH precursor prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.5Co0.15Al0.05O2. The obtained LiNi0.8Co0.15Al0.05O2 materials showed excellent electrochemical performance, with an initial discharge capacity of 193.5 mAh/g and capacity retention of 95.1% after 50 cycles when cycled at 0.2 C rate between 2.8 and 4.3 V.
