In this paper,we study the existence of least energy solutions for the following nonlinear fractional Schrodinger–Poisson system{(−∆)^(s)u+V(x)u+φu=f(u)in R^(3),(−∆)^(t)φ=u^(2)in R^(3),where s∈(3/4,1),t∈(0,1).Und...In this paper,we study the existence of least energy solutions for the following nonlinear fractional Schrodinger–Poisson system{(−∆)^(s)u+V(x)u+φu=f(u)in R^(3),(−∆)^(t)φ=u^(2)in R^(3),where s∈(3/4,1),t∈(0,1).Under some assumptions on V(x)and f,using Nehari–Pohozaev identity and the arguments of Brezis–Nirenberg,the monotonic trick and global compactness lemma,we prove the existence of a nontrivial least energy solution.展开更多
Hydrogen storage plays a crucial role in achieving net-zero emissions by enabling large-scale energy storage,balancing renewable energy fluctuations,and ensuring a stable supply for various applications.This study pro...Hydrogen storage plays a crucial role in achieving net-zero emissions by enabling large-scale energy storage,balancing renewable energy fluctuations,and ensuring a stable supply for various applications.This study provides a comprehensive analysis of hydrogen storage technologies,with a particular focus on underground storage in geological formations such as salt caverns,depleted gas reservoirs,and aquifers.These formations offer high-capacity storage solutions,with salt caverns capable of holding up to 6 TWh of hydrogen and depleted gas reservoirs exceeding 1 TWh per site.Case studies from leading projects demonstrate the feasibility of underground hydrogen storage(UHS)in reducing energy intermittency and enhancing supply security.Challenges such as hydrogen leakage,groundwater contamination,induced seismicity,and economic constraints remain critical concerns.Our findings highlight the technical,economic,and regulatory considerations for integrating UHS into the oil and gas industry,emphasizing its role in sustainable energy transition and decarbonization strategies.展开更多
In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 rep...In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 represents a trapping potential,and f has an exponential critical growth.Under the appropriate assumptions of f,we have obtained the existence of normalized solutions to the above Schr?dinger equation by introducing a variational method.And these solutions are also high energy solutions with positive energy.展开更多
On November 24,the Chinese Academy of Sciences(CAS)launched an international science program for research on burning plasma and released its research plan for the Burning Plasma Experimental Superconducting Tokamak(BE...On November 24,the Chinese Academy of Sciences(CAS)launched an international science program for research on burning plasma and released its research plan for the Burning Plasma Experimental Superconducting Tokamak(BEST),also known as an“artificial sun.”展开更多
Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind ene...Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.展开更多
Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste an...Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste and improve energy efficiency in industrial applications.This research investigates the potential of electromagnetic induction for harvesting rotational kinetic energy from industrial machinery.A comparative study was conducted between disk and cylinder-shaped rotational bodies to evaluate their energy efficiency under various load conditions.Experimental results demonstrated that the disk body exhibited higher energy efficiency,primarily due to lower mechanical losses compared to the cylinder body.A power management circuit was developed to regulate and store the harvested energy,integrating voltage,current,and speed sensors along with a charge controller for battery storage.The experimental setup successfully converted rotational kinetic energy into usable electrical power,with the disk achieving up to 16.33 J of recycled energy,outperforming the cylinder.The disk body demonstrated higher energy recovery efficiency compared to the cylinder,particularly under the 40 W resistive load condition.These findings demonstrate the feasibility of implementing energy recycling systems in industrial settings to enhance sustainability,reduce energy consumption,and minimize waste.Future research should focus on optimizing power management systems and improving energy harvesting efficiency to enable wider adoption of energy recycling technologies in various industrial applications.展开更多
The water-energy nexus is a key area of focus in efforts to achieve the United Nation’s Sustainable Development Goals.As population growth and climate change continue to strain both water and energy systems,innovativ...The water-energy nexus is a key area of focus in efforts to achieve the United Nation’s Sustainable Development Goals.As population growth and climate change continue to strain both water and energy systems,innovative and integrated solutions are required that take into account the inextricable interdependen-cies of these systems.Optimizing resource use,reducing carbon emissions,and increasing system resilience are no longer optional;they are critical imperatives for a sustainable future.This special issue of Engineering presents groundbreaking research exploring the synergies and tradeoffs within the water-energy nexus,offer-ing invaluable insights for policymakers,engineers,and researchers.展开更多
We study a class of semilinear SchrSdinger equation with electromagnetic fields and the nonlinearity term involving critical growth. We assume that the potential of the equation includes a parameter A and can be negat...We study a class of semilinear SchrSdinger equation with electromagnetic fields and the nonlinearity term involving critical growth. We assume that the potential of the equation includes a parameter A and can be negative in some domain. Moreover, the potential behaves like potential well when the parameter A is large. Using variational methods combining Nehari methods, we prove that the equation has a least energy solution which, as the parameter A becomes large, localized near the bottom of the potential well. Our result is an extension of the corresponding result for the SchrSdinger equation which involves critical growth but does not involve electromagnetic fields.展开更多
We are concerned with the existence of least energy solutions of nonlinear Schrodinger equations involving the fractional Laplacian（-△）%s u（x）＋λV（x）u（x）=u（x）^（p-1）,u（x）〉=0,x∈R^N,for sufficiently lar...We are concerned with the existence of least energy solutions of nonlinear Schrodinger equations involving the fractional Laplacian（-△）%s u（x）＋λV（x）u（x）=u（x）^（p-1）,u（x）〉=0,x∈R^N,for sufficiently large λ,2〈p〈N-2s^-2N for N≥2. V（x） is a real continuous function on RN. Using variational methods we prove the existence of least energy solution uλ（x） which localizes near the potential well int V-1 （0） for A large. Moreover, if the zero sets int V-1 （0） of V（x） include more than one isolated component, then ux（x） will be trapped around all the isolated components. However, in Laplacian case s = 1, when the parameter A is large, the corresponding least energy solution will be trapped around only one isolated component and become arbitrarily small in other components of int V^-1（0）. This is the essential difference with the Laplacian problems since the operator （-△）s is nonlocal.展开更多
Consider the following Neumann problem d△u- u ＋ k（x）u^p = 0 and u 〉 0 in B1, δu/δv =0 on OB1,where d 〉 0, B1 is the unit ball in R^N, k（x） = k（｜x｜） ≠ 0 is nonnegative and in C（-↑B1）, 1 〈 p 〈 N＋2/N...Consider the following Neumann problem d△u- u ＋ k（x）u^p = 0 and u 〉 0 in B1, δu/δv =0 on OB1,where d 〉 0, B1 is the unit ball in R^N, k（x） = k（｜x｜） ≠ 0 is nonnegative and in C（-↑B1）, 1 〈 p 〈 N＋2/N-2 with N≥ 3. It was shown in [2] that, for any d 〉 0, problem （＊） has no nonconstant radially symmetric least energy solution if k（x） ≡ 1. By an implicit function theorem we prove that there is d0 〉 0 such that （＊） has a unique radially symmetric least energy solution if d 〉 d0, this solution is constant if k（x） ≡ 1 and nonconstant if k（x） ≠ 1. In particular, for k（x） ≡ 1, do can be expressed explicitly.展开更多
The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is...The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is a promising candidate [1,2]. Some noblemetal-based (e.g., Pt, Pd and Rh) catalysts exhibit significant catalytic activity to the conversion reaction of these biomass.展开更多
Bangladesh has achieved notable progress in expanding electricity access nationwide.Nonetheless,remote and topographically challenging regions such as the Chittagong Hill Tracts(CHT)continue to face coverage gaps due ...Bangladesh has achieved notable progress in expanding electricity access nationwide.Nonetheless,remote and topographically challenging regions such as the Chittagong Hill Tracts(CHT)continue to face coverage gaps due to grid extension difficulties.This research investigates the technical feasibility of micro-hydro power(MHP)systems as viable off-grid solutions for rural electrification in CHT.Field surveys conducted across various sites assessed available head and flow rates using GPS-based elevation measurements and portable flowmeters.Seasonal fluctuations were factored into the analysis to ensure year-round operational viability.The study involved estimating power output,selecting appropriate turbine types based on head-flow data,and proposing preliminary plant configurations.Results identify multiple locations with adequate head(2.5 to 10.4 m)and flow rates(0.10 to 0.35 m3/s),capable of generating between 1.5 and 16.5 kW,sufficient for essential rural applications.Based on site-specific head and discharge characteristics,Kaplan and Francis turbines were identified as the most suitable configurations,offering high efficiency for the medium-flow,low-to-medium head environments typical of the studied regions.Despite inherent technical potential,challenges such as seasonal variability,infrastructure complexities,and policy deficiencies remain.This investigation addresses a critical knowledge gap in local renewable energy planning.It offers a data-driven foundation for pilot projects and community-scale electrification initiatives in Bangladesh’s remote mountainous areas.展开更多
SHANGHAI is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by lowcarbon and energy-saving solu...SHANGHAI is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by lowcarbon and energy-saving solutions.On September 10,China Today visited two enterprises in Shanghai–Shanghai Schneider Electric Industrial Control Co.,Ltd.and Huaqin Technology Co.,Ltd.–to observe firsthand how global investment and local innovation are jointly shaping Shanghai’s future of high-quality development.展开更多
In this paper,we are concerned with the following nonlocal Schrödinger equations-L_(K)u+V(x)u=f(x,u),x∈R^(N),Rwhere L_(K)Lis an integro-differential operator of fractional Laplacian type and V is coercive at inf...In this paper,we are concerned with the following nonlocal Schrödinger equations-L_(K)u+V(x)u=f(x,u),x∈R^(N),Rwhere L_(K)Lis an integro-differential operator of fractional Laplacian type and V is coercive at infinity.Combining the Nehari manifold and the quantitative deformation lemma,a least energy sign-changing solution was obtained,and the energy doubling phenomenon was also found.展开更多
In this paper, we prove the existence and uniqueness of the weak solution to the incompressible Navier-Stokes-Landau-Lifshitz equations in two-dimension with finite energy.The main techniques is the Faedo-Galerkin app...In this paper, we prove the existence and uniqueness of the weak solution to the incompressible Navier-Stokes-Landau-Lifshitz equations in two-dimension with finite energy.The main techniques is the Faedo-Galerkin approximation and weak compactness theory.展开更多
Using results from various reactions that populate 10He, I conclude that the ground state has E2n = 1.07（7） MeV and the excited 0＋ state is in the region of 2.1-3.1 MeV. The amount of the （sd）2 component in the g...Using results from various reactions that populate 10He, I conclude that the ground state has E2n = 1.07（7） MeV and the excited 0＋ state is in the region of 2.1-3.1 MeV. The amount of the （sd）2 component in the ground state is less than about 0.075.展开更多
CSSC Power and Shanghai CSSC Mitsui Shipbuilding Diesel Engine jointly held CPGC/CMD-MAN B&W 12G95ME-C10.5-LGIM-EGRTC methanol Engine FAT handover ceremony,the latter is a subsidiary of MAN Energy Solutions(now re...CSSC Power and Shanghai CSSC Mitsui Shipbuilding Diesel Engine jointly held CPGC/CMD-MAN B&W 12G95ME-C10.5-LGIM-EGRTC methanol Engine FAT handover ceremony,the latter is a subsidiary of MAN Energy Solutions(now renamed Everllence)at CSSCPower.Based on MAN-ES latest generation LGIM design platform and control logics,the engine reliability and stability further improve;each engine is furnished with the exhaust recirculation emission system independently developed by Everllence,which is the largest dual-channel exhaust gas recirculation system for the two-stroke engine.展开更多
The challenges and the path towards a(more)electronic transmission and distribution(eT&D)is presented in this paper.The challenges are first identified together with key stakeholders in the drive for grid moderniz...The challenges and the path towards a(more)electronic transmission and distribution(eT&D)is presented in this paper.The challenges are first identified together with key stakeholders in the drive for grid modernization.A fundamental question is then asked about the investment priority.Six basic characteristics are reviewed,leading to the composition of structured microgrids as the basic functional cell of a modern grid.One example of fractal radial structure and one fractal meshed structure are presented.The likely evolution path is then proposed together with basic technology sets.Specific foundation technologies are discussed in detail,including adiabatic power conversion,3MC technology,medium voltage conversion,distribution-level electronic power transformer and FACTs hardware integration,and back-to-back converters as a universal interconnect element.The rapidly emerging on-wire sensing technology is also discussed.It is pointed out that the distribution-level large electronic power transformer will provide a key component to enable hybrid ac/dc grid flow control and ancillary support for a flexible electronic transmission and distribution(eT&D)systems.展开更多
We consider the following Hamiltonian system: q″(t)+V′(q(t))=0 q ∈C^2(R,R^n\{0}) (HS) where V ∈C^2(R^n\{0},R)is an even function.By looking for closed geodesics,we prove that (HS)has a nonconstant periodic solutio...We consider the following Hamiltonian system: q″(t)+V′(q(t))=0 q ∈C^2(R,R^n\{0}) (HS) where V ∈C^2(R^n\{0},R)is an even function.By looking for closed geodesics,we prove that (HS)has a nonconstant periodic solution of prescribed energy under suitable assumptions.Our main assumption is related with the strong force condition of Gordon.展开更多
基金Supported by NSFC(No.12561023)partly by the Provincial Natural Science Foundation of Jiangxi,China(Nos.20232BAB201001,20202BAB211004)。
文摘In this paper,we study the existence of least energy solutions for the following nonlinear fractional Schrodinger–Poisson system{(−∆)^(s)u+V(x)u+φu=f(u)in R^(3),(−∆)^(t)φ=u^(2)in R^(3),where s∈(3/4,1),t∈(0,1).Under some assumptions on V(x)and f,using Nehari–Pohozaev identity and the arguments of Brezis–Nirenberg,the monotonic trick and global compactness lemma,we prove the existence of a nontrivial least energy solution.
基金Hakim Sabzevari University for supporting this research。
文摘Hydrogen storage plays a crucial role in achieving net-zero emissions by enabling large-scale energy storage,balancing renewable energy fluctuations,and ensuring a stable supply for various applications.This study provides a comprehensive analysis of hydrogen storage technologies,with a particular focus on underground storage in geological formations such as salt caverns,depleted gas reservoirs,and aquifers.These formations offer high-capacity storage solutions,with salt caverns capable of holding up to 6 TWh of hydrogen and depleted gas reservoirs exceeding 1 TWh per site.Case studies from leading projects demonstrate the feasibility of underground hydrogen storage(UHS)in reducing energy intermittency and enhancing supply security.Challenges such as hydrogen leakage,groundwater contamination,induced seismicity,and economic constraints remain critical concerns.Our findings highlight the technical,economic,and regulatory considerations for integrating UHS into the oil and gas industry,emphasizing its role in sustainable energy transition and decarbonization strategies.
基金Supported by National Natural Science Foundation of China(Grant Nos.11671403 and 11671236)Henan Provincial General Natural Science Foundation Project(Grant No.232300420113)。
文摘In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 represents a trapping potential,and f has an exponential critical growth.Under the appropriate assumptions of f,we have obtained the existence of normalized solutions to the above Schr?dinger equation by introducing a variational method.And these solutions are also high energy solutions with positive energy.
文摘On November 24,the Chinese Academy of Sciences(CAS)launched an international science program for research on burning plasma and released its research plan for the Burning Plasma Experimental Superconducting Tokamak(BEST),also known as an“artificial sun.”
基金The APC was funded by Research Management Center, Multimedia University, Malaysia.
文摘Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.
文摘Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste and improve energy efficiency in industrial applications.This research investigates the potential of electromagnetic induction for harvesting rotational kinetic energy from industrial machinery.A comparative study was conducted between disk and cylinder-shaped rotational bodies to evaluate their energy efficiency under various load conditions.Experimental results demonstrated that the disk body exhibited higher energy efficiency,primarily due to lower mechanical losses compared to the cylinder body.A power management circuit was developed to regulate and store the harvested energy,integrating voltage,current,and speed sensors along with a charge controller for battery storage.The experimental setup successfully converted rotational kinetic energy into usable electrical power,with the disk achieving up to 16.33 J of recycled energy,outperforming the cylinder.The disk body demonstrated higher energy recovery efficiency compared to the cylinder,particularly under the 40 W resistive load condition.These findings demonstrate the feasibility of implementing energy recycling systems in industrial settings to enhance sustainability,reduce energy consumption,and minimize waste.Future research should focus on optimizing power management systems and improving energy harvesting efficiency to enable wider adoption of energy recycling technologies in various industrial applications.
文摘The water-energy nexus is a key area of focus in efforts to achieve the United Nation’s Sustainable Development Goals.As population growth and climate change continue to strain both water and energy systems,innovative and integrated solutions are required that take into account the inextricable interdependen-cies of these systems.Optimizing resource use,reducing carbon emissions,and increasing system resilience are no longer optional;they are critical imperatives for a sustainable future.This special issue of Engineering presents groundbreaking research exploring the synergies and tradeoffs within the water-energy nexus,offer-ing invaluable insights for policymakers,engineers,and researchers.
基金supported by Fundamental Research Funds for the Central Universities and National Natural Science Foundation of China(Grant No.11171028)
文摘We study a class of semilinear SchrSdinger equation with electromagnetic fields and the nonlinearity term involving critical growth. We assume that the potential of the equation includes a parameter A and can be negative in some domain. Moreover, the potential behaves like potential well when the parameter A is large. Using variational methods combining Nehari methods, we prove that the equation has a least energy solution which, as the parameter A becomes large, localized near the bottom of the potential well. Our result is an extension of the corresponding result for the SchrSdinger equation which involves critical growth but does not involve electromagnetic fields.
基金supported by National Natural Science Foundation of China (Grant No. 11171028)
文摘We are concerned with the existence of least energy solutions of nonlinear Schrodinger equations involving the fractional Laplacian（-△）%s u（x）＋λV（x）u（x）=u（x）^（p-1）,u（x）〉=0,x∈R^N,for sufficiently large λ,2〈p〈N-2s^-2N for N≥2. V（x） is a real continuous function on RN. Using variational methods we prove the existence of least energy solution uλ（x） which localizes near the potential well int V-1 （0） for A large. Moreover, if the zero sets int V-1 （0） of V（x） include more than one isolated component, then ux（x） will be trapped around all the isolated components. However, in Laplacian case s = 1, when the parameter A is large, the corresponding least energy solution will be trapped around only one isolated component and become arbitrarily small in other components of int V^-1（0）. This is the essential difference with the Laplacian problems since the operator （-△）s is nonlocal.
基金the National Natural Science Foundation of China(No.10571174,10631030)Chinese Academy oF Sciences grant KJCX3-SYW-S03.
文摘Consider the following Neumann problem d△u- u ＋ k（x）u^p = 0 and u 〉 0 in B1, δu/δv =0 on OB1,where d 〉 0, B1 is the unit ball in R^N, k（x） = k（｜x｜） ≠ 0 is nonnegative and in C（-↑B1）, 1 〈 p 〈 N＋2/N-2 with N≥ 3. It was shown in [2] that, for any d 〉 0, problem （＊） has no nonconstant radially symmetric least energy solution if k（x） ≡ 1. By an implicit function theorem we prove that there is d0 〉 0 such that （＊） has a unique radially symmetric least energy solution if d 〉 d0, this solution is constant if k（x） ≡ 1 and nonconstant if k（x） ≠ 1. In particular, for k（x） ≡ 1, do can be expressed explicitly.
文摘The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is a promising candidate [1,2]. Some noblemetal-based (e.g., Pt, Pd and Rh) catalysts exhibit significant catalytic activity to the conversion reaction of these biomass.
文摘Bangladesh has achieved notable progress in expanding electricity access nationwide.Nonetheless,remote and topographically challenging regions such as the Chittagong Hill Tracts(CHT)continue to face coverage gaps due to grid extension difficulties.This research investigates the technical feasibility of micro-hydro power(MHP)systems as viable off-grid solutions for rural electrification in CHT.Field surveys conducted across various sites assessed available head and flow rates using GPS-based elevation measurements and portable flowmeters.Seasonal fluctuations were factored into the analysis to ensure year-round operational viability.The study involved estimating power output,selecting appropriate turbine types based on head-flow data,and proposing preliminary plant configurations.Results identify multiple locations with adequate head(2.5 to 10.4 m)and flow rates(0.10 to 0.35 m3/s),capable of generating between 1.5 and 16.5 kW,sufficient for essential rural applications.Based on site-specific head and discharge characteristics,Kaplan and Francis turbines were identified as the most suitable configurations,offering high efficiency for the medium-flow,low-to-medium head environments typical of the studied regions.Despite inherent technical potential,challenges such as seasonal variability,infrastructure complexities,and policy deficiencies remain.This investigation addresses a critical knowledge gap in local renewable energy planning.It offers a data-driven foundation for pilot projects and community-scale electrification initiatives in Bangladesh’s remote mountainous areas.
文摘SHANGHAI is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by lowcarbon and energy-saving solutions.On September 10,China Today visited two enterprises in Shanghai–Shanghai Schneider Electric Industrial Control Co.,Ltd.and Huaqin Technology Co.,Ltd.–to observe firsthand how global investment and local innovation are jointly shaping Shanghai’s future of high-quality development.
文摘In this paper,we are concerned with the following nonlocal Schrödinger equations-L_(K)u+V(x)u=f(x,u),x∈R^(N),Rwhere L_(K)Lis an integro-differential operator of fractional Laplacian type and V is coercive at infinity.Combining the Nehari manifold and the quantitative deformation lemma,a least energy sign-changing solution was obtained,and the energy doubling phenomenon was also found.
文摘In this paper, we prove the existence and uniqueness of the weak solution to the incompressible Navier-Stokes-Landau-Lifshitz equations in two-dimension with finite energy.The main techniques is the Faedo-Galerkin approximation and weak compactness theory.
文摘Using results from various reactions that populate 10He, I conclude that the ground state has E2n = 1.07（7） MeV and the excited 0＋ state is in the region of 2.1-3.1 MeV. The amount of the （sd）2 component in the ground state is less than about 0.075.
文摘CSSC Power and Shanghai CSSC Mitsui Shipbuilding Diesel Engine jointly held CPGC/CMD-MAN B&W 12G95ME-C10.5-LGIM-EGRTC methanol Engine FAT handover ceremony,the latter is a subsidiary of MAN Energy Solutions(now renamed Everllence)at CSSCPower.Based on MAN-ES latest generation LGIM design platform and control logics,the engine reliability and stability further improve;each engine is furnished with the exhaust recirculation emission system independently developed by Everllence,which is the largest dual-channel exhaust gas recirculation system for the two-stroke engine.
文摘The challenges and the path towards a(more)electronic transmission and distribution(eT&D)is presented in this paper.The challenges are first identified together with key stakeholders in the drive for grid modernization.A fundamental question is then asked about the investment priority.Six basic characteristics are reviewed,leading to the composition of structured microgrids as the basic functional cell of a modern grid.One example of fractal radial structure and one fractal meshed structure are presented.The likely evolution path is then proposed together with basic technology sets.Specific foundation technologies are discussed in detail,including adiabatic power conversion,3MC technology,medium voltage conversion,distribution-level electronic power transformer and FACTs hardware integration,and back-to-back converters as a universal interconnect element.The rapidly emerging on-wire sensing technology is also discussed.It is pointed out that the distribution-level large electronic power transformer will provide a key component to enable hybrid ac/dc grid flow control and ancillary support for a flexible electronic transmission and distribution(eT&D)systems.
文摘We consider the following Hamiltonian system: q″(t)+V′(q(t))=0 q ∈C^2(R,R^n\{0}) (HS) where V ∈C^2(R^n\{0},R)is an even function.By looking for closed geodesics,we prove that (HS)has a nonconstant periodic solution of prescribed energy under suitable assumptions.Our main assumption is related with the strong force condition of Gordon.
