In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocal...In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocally diffusive species and degenerately diffusive species.We prove that the traveling wavefronts are exponentially stable,when the initial perturbation around the traveling waves decays exponentially as x→-∞,but in other locations,the initial data can be arbitrarily large.The adopted methods are the weighted energy with the comparison principle and squeezing technique.展开更多
Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexib...Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.展开更多
This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x...This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x∈R^(N)\Ω,where Ω R^(N)(N>2)is a bounded domain,μ≥0 and λ>0 are real parameters,H denotes the Heaviside function(H(t)=0 for t<0,H(t)=1 for t>0),and the mixed local and nolocal operator is defined as L(u)=−Δu+(−Δ)^(s)u with(−Δ)^(s) being the restricted fractional Laplace(0<s<1).The exponents satisfy 1<q<2<p.By employing a novel non-smooth variational principle,we establish the existence of an M-solution for this problem and identify a range for the exponent p.展开更多
This essay provides a few critical points of view on Ni Peimin＇s recent English translation of the Analects. It shows that his translations of ren into ＂human-heartedness＂ and of li into ＂ritual propriety＂ may in...This essay provides a few critical points of view on Ni Peimin＇s recent English translation of the Analects. It shows that his translations of ren into ＂human-heartedness＂ and of li into ＂ritual propriety＂ may indicate a willingness to recast these Confucian concepts in the modern ideology of western subjectivism or individualism, whereas Confucianism is not in the direction of such ideologies. Moreover, while Ni seems to offer a ＂no-rule＂ view of Confucian virtue ethics, he cannot deny the existence of moral rules and principles in the Confucian system. It is insufficient for him to emphasize the importance of Confucian ＂instructions＂ or ＂methods＂ as he does without explicating their relations to Confucian rules. Additionally, Ni＇s gongfu Confucianism provides a necessary and healthy step back from the contemporary principlism that has been dominant and popular in contemporary politics, ethics, and applied ethics, but Ni goes too far in denying the importance of the moral rules and principles that are implicit or explicit in the Confucian ritual practices and upheld in Confucius＇s Analects.展开更多
Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-depo...Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.展开更多
Background Clinical brain-computer interface(BCI)for mental disorders is an emerging interdisciplinary research field,posing new ethical concerns and challenges,yet lacking practical ethical governance guidelines for ...Background Clinical brain-computer interface(BCI)for mental disorders is an emerging interdisciplinary research field,posing new ethical concerns and challenges,yet lacking practical ethical governance guidelines for stakeholders and the entire community.Aims This study aims to establish a multidisciplinary consensus of principles for ethical governance of clinical BCI research for mental disorders and offer practical ethical guidance to stakeholders involved.Methods A systematic literature review,symposium and roundtable discussions,and a pre-Delphi(round 0)survey were conducted to form the questionnaire for the three-round modified Delphi study.Two rounds of surveys,followed by a third round of independent interviews of 25 experts from BCI-related research domains,were involved.We conducted quantitative analysis of responses and agreements among experts to reveal the consensus and differences regarding the ethical governance of mental BCI research from a multidisciplinary perspective.Results The Delphi panel emphasised important concerns of ethical review practices and ethical principles within the BCI context,identified qualified and highly influential institutions and personnel in conducting and advancing clinical BCI research,and recognised prioritised aspects in the risk-benefit evaluation.Experts expressed diverse opinions on specific ethical concerns,including concerns about invasive technology,its impact on humanity and potential social consequences.Agreement was reached that the practices of ethical governance of clinical BCI for mental disorders should focus on patient voluntariness,autonomy,long-term effects and related assessments of BCI interventions,as well as privacy protection,transparent reporting and ensuring that the research is conducted in qualified institutions with strong data security.Conclusions Ethical governance of clinical research on BCI for mental disorders should include interdisciplinary experts to balance various needs and incorporate the expertise of different stakeholders to avoid serious ethical issues.It requires scientifically grounded approaches,continuous monitoring and interdisciplinary collaboration to ensure evidence-based policies,comprehensive risk assessments and transparency,thereby promoting responsible innovations and protecting patient rights and well-being.展开更多
NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a nec...NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.展开更多
AlScN piezoelectric films prepared by AlSc alloy sputter targets are essential materials for 5G radio frequency filters.The thermophysical properties of AlSc alloy targets are closely related to their welding processe...AlScN piezoelectric films prepared by AlSc alloy sputter targets are essential materials for 5G radio frequency filters.The thermophysical properties of AlSc alloy targets are closely related to their welding processes and applications.Al-xSc alloys(x=5,10,15,20,25,at%)were prepared by vacuum induction melting,whose purity is mainly determined by the raw materials and the production process.The results reveal that as the Sc content increases from 5at%to 20at%,the volume fraction of the Al_(3)Sc phase in the alloy increases from 26.9%to 80.2%,and the average grain size of the Al_(3)Sc phase increases from 12.9μm to 67.7μm during this period.Additionally,both the coefficient of thermal expansion(CTE)and thermal conductivity(TC)of AlSc alloys exhibit a downward trend.Based on experimental data and first-principles calculations,the effective medium theory and the Turner model effectively predict the TC and CTE of Al-xSc alloys.The optimal characteristic parameter(k0)of the Turner model is determined to be 50.The model predictions align well with the experimental results.展开更多
Let(M,g)be a compact Riemann surface with unit area,h a smooth function on M.The Kazdan-Warner problem is that under what kind of conditions on h the equationΔu=8π-8πhe^(u) has a solution.In this survey article,we ...Let(M,g)be a compact Riemann surface with unit area,h a smooth function on M.The Kazdan-Warner problem is that under what kind of conditions on h the equationΔu=8π-8πhe^(u) has a solution.In this survey article,we shall review the development of this problem along the variational method.展开更多
With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixe...With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixed types.Our primary contribution is the establishment of solution existence,illuminating the dynamics of these complex equations.To tackle this challenging problem,we construct an approximate solution sequence and apply the contraction mapping principle to rigorously prove local solution existence.Our results significantly advance the understanding of nonlinear evolution equations of mixed types.Furthermore,they provide a versatile,powerful approach for tackling analogous challenges across physics,engineering,and applied mathematics,making this work a valuable reference for researchers in these fields.展开更多
This paper delves into the theoretical mechanisms of the electronic structure and optical properties of aluminum-based semiconductors(AlX,X=N,P,As,Sb)and indium-based semiconductors(InX,X=N,P,As,Sb)as potential materi...This paper delves into the theoretical mechanisms of the electronic structure and optical properties of aluminum-based semiconductors(AlX,X=N,P,As,Sb)and indium-based semiconductors(InX,X=N,P,As,Sb)as potential materials for optical devices.Band structure calculations reveal that,except for InSb,all other compounds are direct bandgap semiconductors,with AlN exhibiting a bandgap of 3.245 eV.The valence band maximum of these eight compounds primarily stems from the p-orbitals of Al/In and X.In contrast,the conduction band minimum is influenced by all orbitals,with a predominant contribution from the p-orbitals.The static dielectric constant increased with the expansion of the unit cell volume.Compared to AlX and InX with larger X atoms,AlN and InN showed broader absorption spectra in the near-ultraviolet region and higher photoelectric conductance.Regarding mechanical properties,AlN and InN displayed greater shear and bulk modulus than the other compounds.Moreover,among these eight crystal types,a higher modulus was associated with a lower light loss function value,indicating that AlN and InN have superior transmission efficiency and a wider spectral range in optoelectronic material applications.展开更多
In this paper we study the Freidlin-Wentzell's large deviation principle for the following nonlinear fractional stochastic heat equation driven by Gaussian noise∂/∂tu^(ε)=D_(δ)^(α)(t,x)+√εσ(u^(ε)(t,x))W(t,x...In this paper we study the Freidlin-Wentzell's large deviation principle for the following nonlinear fractional stochastic heat equation driven by Gaussian noise∂/∂tu^(ε)=D_(δ)^(α)(t,x)+√εσ(u^(ε)(t,x))W(t,x),(t,x)∈[0,T]×R,where D_(δ)^(α)is a nonlocal fractional differential operator and W is the Gaussian noise which is white in time and behaves as a fractional Brownian motion with Hurst index H satisfying 3-α/4<H<1/2,in the space variable.The weak convergence approach plays an important role.展开更多
On 17 October 2024,the American Geophysical Union(AGU)in Washington,DC,USA,released the Ethical Framework Principles for Climate Intervention Research[1],a set of guidelines designed to help scientists,funders,policym...On 17 October 2024,the American Geophysical Union(AGU)in Washington,DC,USA,released the Ethical Framework Principles for Climate Intervention Research[1],a set of guidelines designed to help scientists,funders,policymakers,and private entities research and govern geoengineering technologies as ethically as possible.Commissioned in 2022 by the AGU Board of Directors and produced with internal funding only,the document advocates that geoengineering research projects fully consider all possible risks and benefits-environmental,sociocultural,and geopolitical-and include input from any groups such projects might impact.展开更多
Cancer screening is a strategy focused on highrisk populations rather than universal populationwide screening, based on a comprehensive evaluation of epidemiological principles and practical feasibility. The effective...Cancer screening is a strategy focused on highrisk populations rather than universal populationwide screening, based on a comprehensive evaluation of epidemiological principles and practical feasibility. The effectiveness of screening depends on factors such as disease prevalence, as well as the sensitivity and specificity of the screening technology employed.展开更多
The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for ...The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform.展开更多
Over 70 years ago,China proposed the Five Principles of Peaceful Coexistence,which were first embraced by countries such as Myanmar and gradually gained traction across Asia.The Five Principles eventually became widel...Over 70 years ago,China proposed the Five Principles of Peaceful Coexistence,which were first embraced by countries such as Myanmar and gradually gained traction across Asia.The Five Principles eventually became widely recognized norms in international relations and foundational principles of international law,contributing significantly to the post-World War II international order.Decades on,the Five Principles have not faded into history.Rather,they have demonstrated renewed relevance in today’s complex global landscape.展开更多
Optimal impulse control and impulse games provide the cutting-edge frameworks for modeling systems where control actions occur at discrete time points,and optimizing objectives under discontinuous interventions.This r...Optimal impulse control and impulse games provide the cutting-edge frameworks for modeling systems where control actions occur at discrete time points,and optimizing objectives under discontinuous interventions.This review synthesizes the theoretical advancements,computational approaches,emerging challenges,and possible research directions in the field.Firstly,we briefly review the fundamental theory of continuous-time optimal control,including Pontryagin's maximum principle(PMP)and dynamic programming principle(DPP).Secondly,we present the foundational results in optimal impulse control,including necessary conditions and sufficient conditions.Thirdly,we systematize impulse game methodologies,from Nash equilibrium existence theory to the connection between Nash equilibrium and systems stability.Fourthly,we summarize the numerical algorithms including the intelligent computation approaches.Finally,we examine the new trends and challenges in theory and applications as well as computational considerations.展开更多
A heteronuclear dual transition metal atom catalyst is a promising strategy to solve and relieve the increasing energy and environment crisis.However,the role of each atom still does not efficiently differentiate due ...A heteronuclear dual transition metal atom catalyst is a promising strategy to solve and relieve the increasing energy and environment crisis.However,the role of each atom still does not efficiently differentiate due to the high activity but low detectability of each transition metal in the synergistic catalytic process when considering the influence of heteronuclear induced atomic difference for each transition metal atom,thus seriously hindering intrinsic mechanism finding.Herein,we proposed coordinate environment vary induced heterogenization of homonuclear dual-transition metal,which inherits the advantage of heteronuclear transition metal atom catalyst but also controls the variable of the two atoms to explore the underlying mechanism.Based on this proposal,employing density functional theory study and machine learning,23 kinds of homonuclear transition metals are doping in four asymmetric C_(3)N for heterogenization to evaluate the underlying catalytic mechanism.Our results demonstrate that five catalysts exhibit excellent catalytic performance with a low limiting potential of-0.28 to-0.48 V.In the meantime,a new mechanism,"capture-charge distribution-recapturecharge redistribution",is developed for both side-on and end-on configuration.More importantly,the pronate site of the first hydrogenation is identified based on this mechanism.Our work not only initially makes a deep understanding of the transition dual metal-based heteronuclear catalyst indirectly but also broadens the development of complicated homonuclear dual-atom catalysts in the future.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.12261081).
文摘In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocally diffusive species and degenerately diffusive species.We prove that the traveling wavefronts are exponentially stable,when the initial perturbation around the traveling waves decays exponentially as x→-∞,but in other locations,the initial data can be arbitrarily large.The adopted methods are the weighted energy with the comparison principle and squeezing technique.
基金supported by the National Key Research and Development Program of China(2023YFB3809800)the National Natural Science Foundation of China(52172249,52525601)+2 种基金the Chinese Academy of Sciences Talents Program(E2290701)the Jiangsu Province Talents Program(JSSCRC2023545)the Special Fund Project of Carbon Peaking Carbon Neutrality Science and Technology Innovation of Jiangsu Province(BE2022011).
文摘Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.
基金Supported by the National Natural Science Foundation of China(Grant No.12361026)the Discipline Con-struction Fund Project of Northwest Minzu University.
文摘This paper investigates the following mixed local and nonlocal elliptic problem fea-turing concave-convex nonlinearities and a discontinuous right-hand side:{L(u)=H(u−μ)|u|^(p−2)u+λ|u|^(q−2)u,x∈Ω,u≥0,x∈Ω,u=0,x∈R^(N)\Ω,where Ω R^(N)(N>2)is a bounded domain,μ≥0 and λ>0 are real parameters,H denotes the Heaviside function(H(t)=0 for t<0,H(t)=1 for t>0),and the mixed local and nolocal operator is defined as L(u)=−Δu+(−Δ)^(s)u with(−Δ)^(s) being the restricted fractional Laplace(0<s<1).The exponents satisfy 1<q<2<p.By employing a novel non-smooth variational principle,we establish the existence of an M-solution for this problem and identify a range for the exponent p.
文摘This essay provides a few critical points of view on Ni Peimin＇s recent English translation of the Analects. It shows that his translations of ren into ＂human-heartedness＂ and of li into ＂ritual propriety＂ may indicate a willingness to recast these Confucian concepts in the modern ideology of western subjectivism or individualism, whereas Confucianism is not in the direction of such ideologies. Moreover, while Ni seems to offer a ＂no-rule＂ view of Confucian virtue ethics, he cannot deny the existence of moral rules and principles in the Confucian system. It is insufficient for him to emphasize the importance of Confucian ＂instructions＂ or ＂methods＂ as he does without explicating their relations to Confucian rules. Additionally, Ni＇s gongfu Confucianism provides a necessary and healthy step back from the contemporary principlism that has been dominant and popular in contemporary politics, ethics, and applied ethics, but Ni goes too far in denying the importance of the moral rules and principles that are implicit or explicit in the Confucian ritual practices and upheld in Confucius＇s Analects.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0609000)National Natural Science Foundation of China(Grant Nos.52171034 and 52101037)Postdoctoral Fellowship Program of CPSFara(No.GZB20230944).
文摘Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.
基金funded by the Shanghai Philosophy and Social Science Planning Project (2021BZX008)the National Social Science Foundation of China (23BZX110)the National Office for Philosophy and Social Science (20&ZD045).
文摘Background Clinical brain-computer interface(BCI)for mental disorders is an emerging interdisciplinary research field,posing new ethical concerns and challenges,yet lacking practical ethical governance guidelines for stakeholders and the entire community.Aims This study aims to establish a multidisciplinary consensus of principles for ethical governance of clinical BCI research for mental disorders and offer practical ethical guidance to stakeholders involved.Methods A systematic literature review,symposium and roundtable discussions,and a pre-Delphi(round 0)survey were conducted to form the questionnaire for the three-round modified Delphi study.Two rounds of surveys,followed by a third round of independent interviews of 25 experts from BCI-related research domains,were involved.We conducted quantitative analysis of responses and agreements among experts to reveal the consensus and differences regarding the ethical governance of mental BCI research from a multidisciplinary perspective.Results The Delphi panel emphasised important concerns of ethical review practices and ethical principles within the BCI context,identified qualified and highly influential institutions and personnel in conducting and advancing clinical BCI research,and recognised prioritised aspects in the risk-benefit evaluation.Experts expressed diverse opinions on specific ethical concerns,including concerns about invasive technology,its impact on humanity and potential social consequences.Agreement was reached that the practices of ethical governance of clinical BCI for mental disorders should focus on patient voluntariness,autonomy,long-term effects and related assessments of BCI interventions,as well as privacy protection,transparent reporting and ensuring that the research is conducted in qualified institutions with strong data security.Conclusions Ethical governance of clinical research on BCI for mental disorders should include interdisciplinary experts to balance various needs and incorporate the expertise of different stakeholders to avoid serious ethical issues.It requires scientifically grounded approaches,continuous monitoring and interdisciplinary collaboration to ensure evidence-based policies,comprehensive risk assessments and transparency,thereby promoting responsible innovations and protecting patient rights and well-being.
文摘NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.
基金National Key Research and Development Program of China(2022YFB3504402,2023YFB3610101)。
文摘AlScN piezoelectric films prepared by AlSc alloy sputter targets are essential materials for 5G radio frequency filters.The thermophysical properties of AlSc alloy targets are closely related to their welding processes and applications.Al-xSc alloys(x=5,10,15,20,25,at%)were prepared by vacuum induction melting,whose purity is mainly determined by the raw materials and the production process.The results reveal that as the Sc content increases from 5at%to 20at%,the volume fraction of the Al_(3)Sc phase in the alloy increases from 26.9%to 80.2%,and the average grain size of the Al_(3)Sc phase increases from 12.9μm to 67.7μm during this period.Additionally,both the coefficient of thermal expansion(CTE)and thermal conductivity(TC)of AlSc alloys exhibit a downward trend.Based on experimental data and first-principles calculations,the effective medium theory and the Turner model effectively predict the TC and CTE of Al-xSc alloys.The optimal characteristic parameter(k0)of the Turner model is determined to be 50.The model predictions align well with the experimental results.
文摘Let(M,g)be a compact Riemann surface with unit area,h a smooth function on M.The Kazdan-Warner problem is that under what kind of conditions on h the equationΔu=8π-8πhe^(u) has a solution.In this survey article,we shall review the development of this problem along the variational method.
基金Supported by the National Natural Science Foundation of China(12201368,62376252)Key Project of Natural Science Foundation of Zhejiang Province(LZ22F030003)Zhejiang Province Leading Geese Plan(2024C02G1123882,2024C01SA100795).
文摘With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixed types.Our primary contribution is the establishment of solution existence,illuminating the dynamics of these complex equations.To tackle this challenging problem,we construct an approximate solution sequence and apply the contraction mapping principle to rigorously prove local solution existence.Our results significantly advance the understanding of nonlinear evolution equations of mixed types.Furthermore,they provide a versatile,powerful approach for tackling analogous challenges across physics,engineering,and applied mathematics,making this work a valuable reference for researchers in these fields.
文摘This paper delves into the theoretical mechanisms of the electronic structure and optical properties of aluminum-based semiconductors(AlX,X=N,P,As,Sb)and indium-based semiconductors(InX,X=N,P,As,Sb)as potential materials for optical devices.Band structure calculations reveal that,except for InSb,all other compounds are direct bandgap semiconductors,with AlN exhibiting a bandgap of 3.245 eV.The valence band maximum of these eight compounds primarily stems from the p-orbitals of Al/In and X.In contrast,the conduction band minimum is influenced by all orbitals,with a predominant contribution from the p-orbitals.The static dielectric constant increased with the expansion of the unit cell volume.Compared to AlX and InX with larger X atoms,AlN and InN showed broader absorption spectra in the near-ultraviolet region and higher photoelectric conductance.Regarding mechanical properties,AlN and InN displayed greater shear and bulk modulus than the other compounds.Moreover,among these eight crystal types,a higher modulus was associated with a lower light loss function value,indicating that AlN and InN have superior transmission efficiency and a wider spectral range in optoelectronic material applications.
基金Partially supported by NSFC(No.11701304)the K.C.Wong Education Foundation。
文摘In this paper we study the Freidlin-Wentzell's large deviation principle for the following nonlinear fractional stochastic heat equation driven by Gaussian noise∂/∂tu^(ε)=D_(δ)^(α)(t,x)+√εσ(u^(ε)(t,x))W(t,x),(t,x)∈[0,T]×R,where D_(δ)^(α)is a nonlocal fractional differential operator and W is the Gaussian noise which is white in time and behaves as a fractional Brownian motion with Hurst index H satisfying 3-α/4<H<1/2,in the space variable.The weak convergence approach plays an important role.
文摘On 17 October 2024,the American Geophysical Union(AGU)in Washington,DC,USA,released the Ethical Framework Principles for Climate Intervention Research[1],a set of guidelines designed to help scientists,funders,policymakers,and private entities research and govern geoengineering technologies as ethically as possible.Commissioned in 2022 by the AGU Board of Directors and produced with internal funding only,the document advocates that geoengineering research projects fully consider all possible risks and benefits-environmental,sociocultural,and geopolitical-and include input from any groups such projects might impact.
文摘Cancer screening is a strategy focused on highrisk populations rather than universal populationwide screening, based on a comprehensive evaluation of epidemiological principles and practical feasibility. The effectiveness of screening depends on factors such as disease prevalence, as well as the sensitivity and specificity of the screening technology employed.
文摘The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform.
基金phased achievement of the Yunnan Provincial Philosophy and Social Sciences Innovation Team project titled Research on Ethnic Issues and Their Impact in Northern Myanmar(No.2025CX09).
文摘Over 70 years ago,China proposed the Five Principles of Peaceful Coexistence,which were first embraced by countries such as Myanmar and gradually gained traction across Asia.The Five Principles eventually became widely recognized norms in international relations and foundational principles of international law,contributing significantly to the post-World War II international order.Decades on,the Five Principles have not faded into history.Rather,they have demonstrated renewed relevance in today’s complex global landscape.
文摘Optimal impulse control and impulse games provide the cutting-edge frameworks for modeling systems where control actions occur at discrete time points,and optimizing objectives under discontinuous interventions.This review synthesizes the theoretical advancements,computational approaches,emerging challenges,and possible research directions in the field.Firstly,we briefly review the fundamental theory of continuous-time optimal control,including Pontryagin's maximum principle(PMP)and dynamic programming principle(DPP).Secondly,we present the foundational results in optimal impulse control,including necessary conditions and sufficient conditions.Thirdly,we systematize impulse game methodologies,from Nash equilibrium existence theory to the connection between Nash equilibrium and systems stability.Fourthly,we summarize the numerical algorithms including the intelligent computation approaches.Finally,we examine the new trends and challenges in theory and applications as well as computational considerations.
基金supported by Guizhou Provincial Basic Research Program(Natural Science)(Qiankehe Foundation-ZK[2022]General 308,the National Natural Science Foundation of China(Grant No.12164009,52262031,12304259,12005046),QKHJC-ZK[2023]YB284)top scientific and technological talents in Guizhou Province(Qian Jiaoji[2022]No.078)+4 种基金Functional Materials and Devices Technology Innovation Team of Guizhou Province University(Qian Jiaoji[2023]058)the Open Project Program of Shanxi Key Laboratory of Advanced Semiconductor Optoelectronic Devices and Integrated Systems(No.2023SZKF01)Key Research and Development Prejects of Shanxi Priovince(202102030201004,202201030201009)Guizhou Normal University Academic New Talent Fund(No.Guizhou Normal New Talent[2022]06)supported in part by the Construction of Key Technology Innovation Talent Team for Micro-Nano Infor。
文摘A heteronuclear dual transition metal atom catalyst is a promising strategy to solve and relieve the increasing energy and environment crisis.However,the role of each atom still does not efficiently differentiate due to the high activity but low detectability of each transition metal in the synergistic catalytic process when considering the influence of heteronuclear induced atomic difference for each transition metal atom,thus seriously hindering intrinsic mechanism finding.Herein,we proposed coordinate environment vary induced heterogenization of homonuclear dual-transition metal,which inherits the advantage of heteronuclear transition metal atom catalyst but also controls the variable of the two atoms to explore the underlying mechanism.Based on this proposal,employing density functional theory study and machine learning,23 kinds of homonuclear transition metals are doping in four asymmetric C_(3)N for heterogenization to evaluate the underlying catalytic mechanism.Our results demonstrate that five catalysts exhibit excellent catalytic performance with a low limiting potential of-0.28 to-0.48 V.In the meantime,a new mechanism,"capture-charge distribution-recapturecharge redistribution",is developed for both side-on and end-on configuration.More importantly,the pronate site of the first hydrogenation is identified based on this mechanism.Our work not only initially makes a deep understanding of the transition dual metal-based heteronuclear catalyst indirectly but also broadens the development of complicated homonuclear dual-atom catalysts in the future.
