Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temp...Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.展开更多
In this study,COMSOL v5.2 Multiphysics software was utilized to perform coupled neutronics and thermal–hydraulics simulations of a molten salt fast reactor,and the SCALE v6.1 code package was utilized to generate the...In this study,COMSOL v5.2 Multiphysics software was utilized to perform coupled neutronics and thermal–hydraulics simulations of a molten salt fast reactor,and the SCALE v6.1 code package was utilized to generate the homogenized cross-section data library.The library’s 238 cross-section groups were categorized into nine groups for the simulations in this study.The results of the COMSOL model under no fuel flow conditions were verified using the SCALE v6.1 code results,and the results of the neutronics and thermal–hydraulics simulations were compared to the results of previously published studies.The results indicated that the COMSOL model that includes the cross-section library generated by the SCALE v6.1 code package is suitable for the steady-state analysis and design assessment of molten salt fast reactors.Subsequently,this model was utilized to investigate the neutronics and thermal–hydraulics behaviors of the reactor.Multiple designs were simulated and analyzed in this model,and the results indicated that even if the wall of the core is curved,hot spots occur in the upper and lower portions of the core’s center near the reflectors.A new design was proposed that utilizes a flow rate distribution system,and the simulation results of this design showed that the maximum temperature in the core was approximately 1032 K and no hot spots occurred.展开更多
In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for ...In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for undamped HE(integrable case)and approximate/semi-analytical solution to the damped HE(non-integrable case)are given for any arbitrary initial conditions.As a special case,the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is reported.In general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic function.In addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in details.Also,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two approximations.Furthermore,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be estimated.As real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model.展开更多
The present paper is basically written as a non-apologetic strong defence of the thesis that computation is part and parcel of a physical theory and by no means a mere numerical evaluation of the prediction of a theor...The present paper is basically written as a non-apologetic strong defence of the thesis that computation is part and parcel of a physical theory and by no means a mere numerical evaluation of the prediction of a theory which comes towards the end. Various general considerations as well as specific examples are given to illustrate and support our arguments. These examples range from the practical aspect to almost esoteric considerations but at the end, everything converges towards a unity of theory and computation presented in the form of modern fractal logic and transfinite quantum field theory in a Cantorian spacetime. It is true that all our examples are taken from physics but our discussion is applicable in equal measure to a much wider aspect of life.展开更多
The present note is basically an announcement of a theoretical and experimental resolution of one of the most basic fundamental problems of physics, namely the very existence and reality of the Aether [1-11]. This is ...The present note is basically an announcement of a theoretical and experimental resolution of one of the most basic fundamental problems of physics, namely the very existence and reality of the Aether [1-11]. This is not only basic philosophy of science or insightful results in theoretical physics and cosmology [1-24] but more than that because it may lead to actually realizing the futuristic dream of free energy [25-28]. Our mathematical and indirect experimental verdict is that the Aether exists and it can be equated to the empty set of pure mathematics [3, 12-16]. More precisely the Aether may be understood for all mathematical and physical purposes as being identical to the empty set [8-14] underlying the Penrose fractal tessellation universe [17] which obeys the A. Connes’ corresponding dimensional function of his noncommutative geometry [18-21].展开更多
At its most basic level physics starts with space-time topology and geometry. On the other hand topology’s and geometry’s simplest and most basic elements are random Cantor sets. It follows then that nonlinear dynam...At its most basic level physics starts with space-time topology and geometry. On the other hand topology’s and geometry’s simplest and most basic elements are random Cantor sets. It follows then that nonlinear dynamics i.e. deterministic chaos and fractal geometry is the best mathematical theory to apply to the problems of high energy particle physics and cosmology. In the present work we give a short survey of some recent achievements of applying nonlinear dynamics to notoriously difficult subjects such as quantum entanglement as well as the origin and true nature of dark energy, negative absolute temperature and the fractal meaning of the constancy of the speed of light.展开更多
A straightforward simple proof is given that dark energy is the natural conse-quence of a quantum disentanglement physical process. Thus while the ordinary energy density of the cosmos is equal to half that of Hardy’...A straightforward simple proof is given that dark energy is the natural conse-quence of a quantum disentanglement physical process. Thus while the ordinary energy density of the cosmos is equal to half that of Hardy’s quantum probability of Entanglement i.e. where , the density of cosmic dark energy is consequently one minus divided by two i.e. . This result is in full agreement with all the numerous previous theoretical predictions as well as being in remarkable agreement with the overwhelming majority of cosmic accurate measurements and observations.展开更多
By religiously adhering to physics in spacetime and taking the final verdict of N.D. Mermin’s Ithaca interpretation of quantum mechanics seriously, Hardy’s paradox is completely resolved. It is then concluded that l...By religiously adhering to physics in spacetime and taking the final verdict of N.D. Mermin’s Ithaca interpretation of quantum mechanics seriously, Hardy’s paradox is completely resolved. It is then concluded that logical and mathematically consistent physical theories must be put in spacetime related formalism such as noncommutative geometry and E-infinity theory to avoid quantum paradoxes. At a minimum, we should employ the philosophy behind consistent quantum interpretation such as that of the famous Ithaca interpretation of D. Mermin.展开更多
Schrfdinger＇s equation is one the equations that mark the beginnings of the systematic quantum physics. It was shown that it follows from the Dirac＇s equation and the relationship with classical physics, i.e. with c...Schrfdinger＇s equation is one the equations that mark the beginnings of the systematic quantum physics. It was shown that it follows from the Dirac＇s equation and the relationship with classical physics, i.e. with classical field theory was established. The subject of this work is the relationship between classical relativistic physics and the quantum physics. Investigation carded out in this work, shows that the free electromagnetic field, spinor Dirac＇s field without mass, spinor Dirac＇s field with mass, and some other fields are described by the same vibrational formulation. The conditions that a field be described by Maxwell＇s equations of motion are given in this work, and some solutions of these conditions are also given. Non-relativistic approximation of the equations of the non-quantified field are the Schrōdinger＇s equations. Dirac＇s equation as a special case, contains Maxwell＇s equations and the Schrōdinger＇s equation.展开更多
Interest in energy harvesters has grown rapidly over the last decade. The cantilever shaped piezoelectric energy harvesting beam is one of the most employed designs, due to its simplicity and flexibility for further p...Interest in energy harvesters has grown rapidly over the last decade. The cantilever shaped piezoelectric energy harvesting beam is one of the most employed designs, due to its simplicity and flexibility for further performance enhancement. The research effort in the MEMS Piezoelectric vibration energy harvester designed using three types of cantilever materials, Lithium Niobate (LiNbO3), Aluminum Nitride (AlN) and Zinc Oxide (ZnO) with different substrate materials: aluminum, steel and silicon using COMSOL Multiphysics package were designed and analyzed. Voltage, mechanical power and electrical power versus frequency for different cantilever materials and substrates were modeled and simulated using Finite element method (FEM). The resonant frequencies of the LiNbO3/Al, AlN/Al and ZnO/Al systems were found to be 187.5 Hz, 279.5 Hz and 173.5 Hz, respectively. We found that ZnO/Al system yields optimum voltage and electrical power values of 8.2 V and 2.8 mW, respectively. For ZnO cantilever on aluminum, steel and silicon substrates, we found the resonant frequencies to be 173.5 Hz, 170 Hz and 175 Hz, respectively. Interestingly, ZnO/steel yields optimal voltage and electrical power values of 9.83 V and 4.02 mW, respectively. Furthermore, all systems were studied at different differentiate frequencies. We found that voltage and electrical power have increased as the acceleration has increased.展开更多
Modern advances in pure mathematics and particularly in transfinite set theory have introduced into the fundamentals of theoretical physics many novel concepts and devices such as fractal quasi manifolds with non-inte...Modern advances in pure mathematics and particularly in transfinite set theory have introduced into the fundamentals of theoretical physics many novel concepts and devices such as fractal quasi manifolds with non-integer (Hausdorff) dimension for its geometry as well as infinite dimensional wild topology and non classical fuzzy logic. In the present work transfinite fractal sets and fuzzy logic are combined to enable the introduction of a new theory termed fractal logic to the foundation of high energy particle physics. This leads naturally to a new look at quantum gravity. In particular we will show that to understand and develop quantum gravity we have to bring various fields together, particularly fractals and nonlinear dynamics as well as sphere packing, fuzzy set theory, number theory and quantum entanglement and irrationally q-deformed algebra.展开更多
Adenosine triphosphate(ATP)-binding cassette(ABC)transporter systems are divided into importers and exporters that facilitate the movement of diverse substrate molecules across the lipid bilayer,against the concentrat...Adenosine triphosphate(ATP)-binding cassette(ABC)transporter systems are divided into importers and exporters that facilitate the movement of diverse substrate molecules across the lipid bilayer,against the concentration gradient.These transporters comprise two highly conserved nucleotide-binding domains(NBDs)and two transmembrane domains(TMDs).Unlike ABC exporters,prokaryotic ABC importers require an additional substrate-binding protein(SBP)as a recognition site for specific substrate translocation.The discovery of a large number of ABC systems in bacterial pathogens revealed that these transporters are crucial for the establishment of bacterial infections.The existing literature has highlighted the roles of ABC transporters in bacterial growth,pathogenesis,and virulence.These roles include importing essential nutrients required for a variety of cellular processes and exporting outer membrane-associated virulence factors and antimicrobial substances.This review outlines the general structures and classification of ABC systems to provide a comprehensive view of the activities and roles of ABC transporters associated with bacterial virulence and pathogenesis during infection.展开更多
The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(...The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis routes.This review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and nanocrystals.Through a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread implementation.In addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection systems.This review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.展开更多
Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion...Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion batteries(AIBs)including sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).Owing to larger ion sizes of Na^(+)and K^(+)compared with Li^(+),nanocomposites with excellent crystallinity orientation and well-developed porosity show unprecedented potential for advanced lithium/sodium/potassium storage.With enticing open rigid framework structures,Prussian blue analogues(PBAs)remain promising self-sacrificial templates for the preparation of various nanocomposites,whose appeal originates from the well-retained porous structures and exceptional electrochemical activities after thermal decomposition.This review focuses on the recent progress of PBA-derived nanocomposites from their fabrication,lithium/sodium/potassium storage mechanism,and applications in AIBs(LIBs,SIBs,and PIBs).To distinguish various PBA derivatives,the working mechanism and applications of PBA-templated metal oxides,metal chalcogenides,metal phosphides,and other nanocomposites are systematically evaluated,facilitating the establishment of a structure–activity correlation for these materials.Based on the fruitful achievements of PBA-derived nanocomposites,perspectives for their future development are envisioned,aiming to narrow down the gap between laboratory study and industrial reality.展开更多
Thermospheric neutral winds(TNWs)refer to the neutral gases in the thermosphere circulating as tides,which play a crucial role in the dynamics of the thermosphere-ionosphere system(TIS).Global geospace neutral winds,p...Thermospheric neutral winds(TNWs)refer to the neutral gases in the thermosphere circulating as tides,which play a crucial role in the dynamics of the thermosphere-ionosphere system(TIS).Global geospace neutral winds,particularly over the magnetic equator,have been a subject of study for several decades.However,despite the known importance of neutral winds,a comprehensive understanding and characterization of the winds is still lacking.Various ground-based and satellite missions have provided valuable information on the contribution of neutral winds to the global atmospheric dynamics.However,efforts in the global monitoring of neutral winds are still lacking,and the drivers behind the behavior of TNWs as well as their influence on the TIS remain incomplete.To address these knowledge gaps in the global circulation of TNWs,it is crucial to develop a deep understanding of the neutral wind characteristics over different regions.The low-latitude equatorial region in particular has been observed to exert complex influences on TNWs because of the unique effects of the Earth’s magnetic field at the dip equator.Studying neutral winds over this region will provide valuable insights into the unique dynamics and processes that occur in this region,thereby enhancing our understanding of their role in the overall dynamics of the TIS.Additionally,through empirical observations,an improved ability to accurately model and predict the behavior of this region can be achieved.This review article addresses challenges in understanding equatorial winds by reviewing historical measurements,current missions,and the interactions of ionospheric and thermospheric phenomena,emphasizing the need for comprehensive measurements to improve global atmospheric dynamics and weather forecasting.展开更多
Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other s...Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.展开更多
The noise feature of a single-mode class-A laser amplifier is investigated by solving the Maxwell–Bloch equations of motion in the presence of the fluctuation force of cavity Langevin.The aim is to calculate the simu...The noise feature of a single-mode class-A laser amplifier is investigated by solving the Maxwell–Bloch equations of motion in the presence of the fluctuation force of cavity Langevin.The aim is to calculate the simultaneous fluctuations that are superimposed on the amplitude and phase of the cavity electric field, as well as the atomic population inversion. The correlation function of these fluctuations yields the amplitude, phase, and spontaneous emission noise fluxes, respectively. The amplitude and spontaneous emission noise fluxes exhibit the Lorentzian profiles in both the below-threshold state and the injection-locking region of the above-threshold state. While noise is typically viewed negatively in science and engineering, this research highlights its positive role as a valuable tool for measuring the optical properties of a laser amplifier. For instance, the degree of first-order temporal coherence(DFOTC) is derived by taking the Fourier transform of the amplitude noise flux. The damping rate of DFOTC is associated with the coherence time of the light emitted by the laser amplifier. Furthermore, the uncertainty relation between noise bandwidth and coherence time is confirmed. Finally, it is demonstrated that the input pumping noise flux, together with the output amplitude and spontaneous emission noise fluxes, satisfy the principle of flux conservation.展开更多
In science and technology,precision measurement of physical quantities is crucial,and the quantum Fisher information(QFI)plays a significant role in the study of quantum systems.In this work,we explore the dynamics of...In science and technology,precision measurement of physical quantities is crucial,and the quantum Fisher information(QFI)plays a significant role in the study of quantum systems.In this work,we explore the dynamics of QFI in a hybrid optomechanical system,which consists of a◇-type four-level atom interacting with a single-mode quantized field via a multi-photon process.We account for various sources of dissipation,including the decay rates of the atom,the cavity and the mechanical modes.Using an effective Hamiltonian,we analytically derive the explicit form of the state vector of the entire system via the time-dependent Schr?dinger equation.We then investigate the atomic QFI for the estimation precision of the decay rate of the mechanical oscillator.Furthermore,we examine how optomechanical and atom-field coupling strengths,dissipation parameters and multi-photon transition influence the dynamics of atomic QFI.Our numerical results suggest that the estimation precision of the decay rate of the mechanical oscillator can be controlled by these parameters.展开更多
The global reheating observed in these last years is followed with a change of rainfalls bunches at the global and regional area.The floods frequency increasing,dangerously impacts the socio-economic activities of sev...The global reheating observed in these last years is followed with a change of rainfalls bunches at the global and regional area.The floods frequency increasing,dangerously impacts the socio-economic activities of several countries throughout the world.Indeed,for Niger as a country located in West Africa where the majority of the population existence depends on the agricultural and pastoral activities,this change of rainfalls bunches may have unwanted consequences.The aim of this work is to analyze the evolution and trend of rainfall in Niger during the period 2008-2024 compared to the period 1971-2000 characterized by episodes of drought.To achieve the objective of this work,annual data of rainfalls and the number of rainy days from four meteorological stations representative of the four major climatic zones of Niger are used.These are the station of Agadez(in Sahelian zone),the station of Tahoua(in mid Sahelian and Saharan zone),the station of Niamey(in Sahelian zone)and the station of Gaya(in mid Sahelian and Sudden zone).Thus,the standardized index of Lamb(1982)and the least squares method are respectively used to analyze the variability of the interannual rainfalls and their tendency.The results obtained show a significant improvement in rainfall in the four climatic zones compared to the period from 1971 to 2000,and especially in the Nigerien Sahara where 88.2%of the years were wet.The latitudinal gradient South-North of the rainfalls has known an upgrading going from 1 mm/km during the period of 1971-2000 to 1.26 mm/km during the period of 2008-2024.Our results also show that this improvement in rainfall is linked to heavy rainfall events which are the cause of floods observed mainly during wet years(2010,2012,2013,2017,2019 and 2024).Finally,the results show that,excepting the Sahel-Niger,the other climatic zones are experiencing an increasing trend in rainfall.Therefore,in the face of current climate change,West African countries must mobilize to put in place a strategy to mitigate the consequences of heavy rainfall.展开更多
基金the financial support from the Key Project of Shaanxi Provincial Natural Science Foundation-Key Project of Laboratory(2025SYS-SYSZD-117)the Natural Science Basic Research Program of Shaanxi(2025JCYBQN-125)+8 种基金Young Talent Fund of Xi'an Association for Science and Technology(0959202513002)the Key Industrial Chain Technology Research Program of Xi'an(24ZDCYJSGG0048)the Key Research and Development Program of Xianyang(L2023-ZDYF-SF-077)Postdoctoral Fellowship Program of CPSF(GZC20241442)Shaanxi Postdoctoral Science Foundation(2024BSHSDZZ070)Research Funds for the Interdisciplinary Projects,CHU(300104240913)the Fundamental Research Funds for the Central Universities,CHU(300102385739,300102384201,300102384103)the Scientific Innovation Practice Project of Postgraduate of Chang'an University(300103725063)the financial support from the Australian Research Council。
文摘Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.
文摘In this study,COMSOL v5.2 Multiphysics software was utilized to perform coupled neutronics and thermal–hydraulics simulations of a molten salt fast reactor,and the SCALE v6.1 code package was utilized to generate the homogenized cross-section data library.The library’s 238 cross-section groups were categorized into nine groups for the simulations in this study.The results of the COMSOL model under no fuel flow conditions were verified using the SCALE v6.1 code results,and the results of the neutronics and thermal–hydraulics simulations were compared to the results of previously published studies.The results indicated that the COMSOL model that includes the cross-section library generated by the SCALE v6.1 code package is suitable for the steady-state analysis and design assessment of molten salt fast reactors.Subsequently,this model was utilized to investigate the neutronics and thermal–hydraulics behaviors of the reactor.Multiple designs were simulated and analyzed in this model,and the results indicated that even if the wall of the core is curved,hot spots occur in the upper and lower portions of the core’s center near the reflectors.A new design was proposed that utilizes a flow rate distribution system,and the simulation results of this design showed that the maximum temperature in the core was approximately 1032 K and no hot spots occurred.
基金Taif University Researchers Supporting Project number(TURSP-2020/275),Taif University,Taif,Saudi Arabia.
文摘In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for undamped HE(integrable case)and approximate/semi-analytical solution to the damped HE(non-integrable case)are given for any arbitrary initial conditions.As a special case,the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is reported.In general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic function.In addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in details.Also,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two approximations.Furthermore,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be estimated.As real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model.
文摘The present paper is basically written as a non-apologetic strong defence of the thesis that computation is part and parcel of a physical theory and by no means a mere numerical evaluation of the prediction of a theory which comes towards the end. Various general considerations as well as specific examples are given to illustrate and support our arguments. These examples range from the practical aspect to almost esoteric considerations but at the end, everything converges towards a unity of theory and computation presented in the form of modern fractal logic and transfinite quantum field theory in a Cantorian spacetime. It is true that all our examples are taken from physics but our discussion is applicable in equal measure to a much wider aspect of life.
文摘The present note is basically an announcement of a theoretical and experimental resolution of one of the most basic fundamental problems of physics, namely the very existence and reality of the Aether [1-11]. This is not only basic philosophy of science or insightful results in theoretical physics and cosmology [1-24] but more than that because it may lead to actually realizing the futuristic dream of free energy [25-28]. Our mathematical and indirect experimental verdict is that the Aether exists and it can be equated to the empty set of pure mathematics [3, 12-16]. More precisely the Aether may be understood for all mathematical and physical purposes as being identical to the empty set [8-14] underlying the Penrose fractal tessellation universe [17] which obeys the A. Connes’ corresponding dimensional function of his noncommutative geometry [18-21].
文摘At its most basic level physics starts with space-time topology and geometry. On the other hand topology’s and geometry’s simplest and most basic elements are random Cantor sets. It follows then that nonlinear dynamics i.e. deterministic chaos and fractal geometry is the best mathematical theory to apply to the problems of high energy particle physics and cosmology. In the present work we give a short survey of some recent achievements of applying nonlinear dynamics to notoriously difficult subjects such as quantum entanglement as well as the origin and true nature of dark energy, negative absolute temperature and the fractal meaning of the constancy of the speed of light.
文摘A straightforward simple proof is given that dark energy is the natural conse-quence of a quantum disentanglement physical process. Thus while the ordinary energy density of the cosmos is equal to half that of Hardy’s quantum probability of Entanglement i.e. where , the density of cosmic dark energy is consequently one minus divided by two i.e. . This result is in full agreement with all the numerous previous theoretical predictions as well as being in remarkable agreement with the overwhelming majority of cosmic accurate measurements and observations.
文摘By religiously adhering to physics in spacetime and taking the final verdict of N.D. Mermin’s Ithaca interpretation of quantum mechanics seriously, Hardy’s paradox is completely resolved. It is then concluded that logical and mathematically consistent physical theories must be put in spacetime related formalism such as noncommutative geometry and E-infinity theory to avoid quantum paradoxes. At a minimum, we should employ the philosophy behind consistent quantum interpretation such as that of the famous Ithaca interpretation of D. Mermin.
文摘Schrfdinger＇s equation is one the equations that mark the beginnings of the systematic quantum physics. It was shown that it follows from the Dirac＇s equation and the relationship with classical physics, i.e. with classical field theory was established. The subject of this work is the relationship between classical relativistic physics and the quantum physics. Investigation carded out in this work, shows that the free electromagnetic field, spinor Dirac＇s field without mass, spinor Dirac＇s field with mass, and some other fields are described by the same vibrational formulation. The conditions that a field be described by Maxwell＇s equations of motion are given in this work, and some solutions of these conditions are also given. Non-relativistic approximation of the equations of the non-quantified field are the Schrōdinger＇s equations. Dirac＇s equation as a special case, contains Maxwell＇s equations and the Schrōdinger＇s equation.
文摘Interest in energy harvesters has grown rapidly over the last decade. The cantilever shaped piezoelectric energy harvesting beam is one of the most employed designs, due to its simplicity and flexibility for further performance enhancement. The research effort in the MEMS Piezoelectric vibration energy harvester designed using three types of cantilever materials, Lithium Niobate (LiNbO3), Aluminum Nitride (AlN) and Zinc Oxide (ZnO) with different substrate materials: aluminum, steel and silicon using COMSOL Multiphysics package were designed and analyzed. Voltage, mechanical power and electrical power versus frequency for different cantilever materials and substrates were modeled and simulated using Finite element method (FEM). The resonant frequencies of the LiNbO3/Al, AlN/Al and ZnO/Al systems were found to be 187.5 Hz, 279.5 Hz and 173.5 Hz, respectively. We found that ZnO/Al system yields optimum voltage and electrical power values of 8.2 V and 2.8 mW, respectively. For ZnO cantilever on aluminum, steel and silicon substrates, we found the resonant frequencies to be 173.5 Hz, 170 Hz and 175 Hz, respectively. Interestingly, ZnO/steel yields optimal voltage and electrical power values of 9.83 V and 4.02 mW, respectively. Furthermore, all systems were studied at different differentiate frequencies. We found that voltage and electrical power have increased as the acceleration has increased.
文摘Modern advances in pure mathematics and particularly in transfinite set theory have introduced into the fundamentals of theoretical physics many novel concepts and devices such as fractal quasi manifolds with non-integer (Hausdorff) dimension for its geometry as well as infinite dimensional wild topology and non classical fuzzy logic. In the present work transfinite fractal sets and fuzzy logic are combined to enable the introduction of a new theory termed fractal logic to the foundation of high energy particle physics. This leads naturally to a new look at quantum gravity. In particular we will show that to understand and develop quantum gravity we have to bring various fields together, particularly fractals and nonlinear dynamics as well as sphere packing, fuzzy set theory, number theory and quantum entanglement and irrationally q-deformed algebra.
基金supported by the Universiti Kebangsaan Malaysia under the Research University Grant(No.GUP-2020-030)awarded to Sylvia CHIENG.
文摘Adenosine triphosphate(ATP)-binding cassette(ABC)transporter systems are divided into importers and exporters that facilitate the movement of diverse substrate molecules across the lipid bilayer,against the concentration gradient.These transporters comprise two highly conserved nucleotide-binding domains(NBDs)and two transmembrane domains(TMDs).Unlike ABC exporters,prokaryotic ABC importers require an additional substrate-binding protein(SBP)as a recognition site for specific substrate translocation.The discovery of a large number of ABC systems in bacterial pathogens revealed that these transporters are crucial for the establishment of bacterial infections.The existing literature has highlighted the roles of ABC transporters in bacterial growth,pathogenesis,and virulence.These roles include importing essential nutrients required for a variety of cellular processes and exporting outer membrane-associated virulence factors and antimicrobial substances.This review outlines the general structures and classification of ABC systems to provide a comprehensive view of the activities and roles of ABC transporters associated with bacterial virulence and pathogenesis during infection.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.RS-2022–00165798)Anhui Natural Science Foundation(No.2308085MF211)The authors extend their appreciation to the Deanship of Research and Graduate Studies at King Khalid University for funding this work through Large Research Project under Grant Number(R.G.P.2/491/45).
文摘The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis routes.This review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and nanocrystals.Through a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread implementation.In addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection systems.This review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.
基金financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)the Scientific Research Innovation Project of Graduate School of South China Normal University(2024KYLX047)financial support from the Australian Research Council,Centre for Materials Science,Queensland University of Technology.
文摘Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion batteries(AIBs)including sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).Owing to larger ion sizes of Na^(+)and K^(+)compared with Li^(+),nanocomposites with excellent crystallinity orientation and well-developed porosity show unprecedented potential for advanced lithium/sodium/potassium storage.With enticing open rigid framework structures,Prussian blue analogues(PBAs)remain promising self-sacrificial templates for the preparation of various nanocomposites,whose appeal originates from the well-retained porous structures and exceptional electrochemical activities after thermal decomposition.This review focuses on the recent progress of PBA-derived nanocomposites from their fabrication,lithium/sodium/potassium storage mechanism,and applications in AIBs(LIBs,SIBs,and PIBs).To distinguish various PBA derivatives,the working mechanism and applications of PBA-templated metal oxides,metal chalcogenides,metal phosphides,and other nanocomposites are systematically evaluated,facilitating the establishment of a structure–activity correlation for these materials.Based on the fruitful achievements of PBA-derived nanocomposites,perspectives for their future development are envisioned,aiming to narrow down the gap between laboratory study and industrial reality.
基金the Ministry of Higher Education(KPT)Malaysia for the MyBrainSc program.Idahwati Sarudin was supported by Universiti Sains Malaysia through a Short-Term Grant(Project No.304/PFIZIK/6315730)Nurul Shazana Abdul Hamid received funding from Universiti Kebangsaan Malaysia for funding this work through a University Research Grant(Grant No.GUP-2023-048)。
文摘Thermospheric neutral winds(TNWs)refer to the neutral gases in the thermosphere circulating as tides,which play a crucial role in the dynamics of the thermosphere-ionosphere system(TIS).Global geospace neutral winds,particularly over the magnetic equator,have been a subject of study for several decades.However,despite the known importance of neutral winds,a comprehensive understanding and characterization of the winds is still lacking.Various ground-based and satellite missions have provided valuable information on the contribution of neutral winds to the global atmospheric dynamics.However,efforts in the global monitoring of neutral winds are still lacking,and the drivers behind the behavior of TNWs as well as their influence on the TIS remain incomplete.To address these knowledge gaps in the global circulation of TNWs,it is crucial to develop a deep understanding of the neutral wind characteristics over different regions.The low-latitude equatorial region in particular has been observed to exert complex influences on TNWs because of the unique effects of the Earth’s magnetic field at the dip equator.Studying neutral winds over this region will provide valuable insights into the unique dynamics and processes that occur in this region,thereby enhancing our understanding of their role in the overall dynamics of the TIS.Additionally,through empirical observations,an improved ability to accurately model and predict the behavior of this region can be achieved.This review article addresses challenges in understanding equatorial winds by reviewing historical measurements,current missions,and the interactions of ionospheric and thermospheric phenomena,emphasizing the need for comprehensive measurements to improve global atmospheric dynamics and weather forecasting.
基金the National Institute of Information and Communication Technology International Exchange Program 2024−2025(No.2024−007)for their invaluable support in this research.3D tomography software is available at Prof.Kosuke Heki’s(Hokkaido University,Japan)personal homepage(https://www.ep.sci.hokudai.ac.jp/~heki/software.htm).support from the 2024 Japan Student Services Organization Research Follow-up Fellowship for a 90-day research visit at the Institute for Space−Earth Environmental Research,Nagoya University,Japan.PA also acknowledges the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”,and the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation(No:092/SAM3/TE-DEK/2021).
文摘Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.
文摘The noise feature of a single-mode class-A laser amplifier is investigated by solving the Maxwell–Bloch equations of motion in the presence of the fluctuation force of cavity Langevin.The aim is to calculate the simultaneous fluctuations that are superimposed on the amplitude and phase of the cavity electric field, as well as the atomic population inversion. The correlation function of these fluctuations yields the amplitude, phase, and spontaneous emission noise fluxes, respectively. The amplitude and spontaneous emission noise fluxes exhibit the Lorentzian profiles in both the below-threshold state and the injection-locking region of the above-threshold state. While noise is typically viewed negatively in science and engineering, this research highlights its positive role as a valuable tool for measuring the optical properties of a laser amplifier. For instance, the degree of first-order temporal coherence(DFOTC) is derived by taking the Fourier transform of the amplitude noise flux. The damping rate of DFOTC is associated with the coherence time of the light emitted by the laser amplifier. Furthermore, the uncertainty relation between noise bandwidth and coherence time is confirmed. Finally, it is demonstrated that the input pumping noise flux, together with the output amplitude and spontaneous emission noise fluxes, satisfy the principle of flux conservation.
文摘In science and technology,precision measurement of physical quantities is crucial,and the quantum Fisher information(QFI)plays a significant role in the study of quantum systems.In this work,we explore the dynamics of QFI in a hybrid optomechanical system,which consists of a◇-type four-level atom interacting with a single-mode quantized field via a multi-photon process.We account for various sources of dissipation,including the decay rates of the atom,the cavity and the mechanical modes.Using an effective Hamiltonian,we analytically derive the explicit form of the state vector of the entire system via the time-dependent Schr?dinger equation.We then investigate the atomic QFI for the estimation precision of the decay rate of the mechanical oscillator.Furthermore,we examine how optomechanical and atom-field coupling strengths,dissipation parameters and multi-photon transition influence the dynamics of atomic QFI.Our numerical results suggest that the estimation precision of the decay rate of the mechanical oscillator can be controlled by these parameters.
文摘The global reheating observed in these last years is followed with a change of rainfalls bunches at the global and regional area.The floods frequency increasing,dangerously impacts the socio-economic activities of several countries throughout the world.Indeed,for Niger as a country located in West Africa where the majority of the population existence depends on the agricultural and pastoral activities,this change of rainfalls bunches may have unwanted consequences.The aim of this work is to analyze the evolution and trend of rainfall in Niger during the period 2008-2024 compared to the period 1971-2000 characterized by episodes of drought.To achieve the objective of this work,annual data of rainfalls and the number of rainy days from four meteorological stations representative of the four major climatic zones of Niger are used.These are the station of Agadez(in Sahelian zone),the station of Tahoua(in mid Sahelian and Saharan zone),the station of Niamey(in Sahelian zone)and the station of Gaya(in mid Sahelian and Sudden zone).Thus,the standardized index of Lamb(1982)and the least squares method are respectively used to analyze the variability of the interannual rainfalls and their tendency.The results obtained show a significant improvement in rainfall in the four climatic zones compared to the period from 1971 to 2000,and especially in the Nigerien Sahara where 88.2%of the years were wet.The latitudinal gradient South-North of the rainfalls has known an upgrading going from 1 mm/km during the period of 1971-2000 to 1.26 mm/km during the period of 2008-2024.Our results also show that this improvement in rainfall is linked to heavy rainfall events which are the cause of floods observed mainly during wet years(2010,2012,2013,2017,2019 and 2024).Finally,the results show that,excepting the Sahel-Niger,the other climatic zones are experiencing an increasing trend in rainfall.Therefore,in the face of current climate change,West African countries must mobilize to put in place a strategy to mitigate the consequences of heavy rainfall.
