The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overh...The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overheating or localized strain are of great value for the safe use of lithium batteries or film capacitors;however,this function usually requires a system of multiple complex sensors.The realization of the above multiple hazards using a single sensor for monitoring and alarm functions has not been reported.Here,we exploit the thermally induced conductivity and modulus change during solid-liquid conversion of low melting point polyalloys to modulate the electronic relaxation polariza-tion and interfacial polarization in the composites for dielectric switching,and the reduction of alloy particle spacing during bending/compres-sive strain can be used to generate switchable tunneling effects for insulator-conductor transition.By synergizing dielectric switching and insula-tor-conductor transition,the final flexible thermoplastic polyurethane elastomer/low-melting-point polyalloy composite film achieves the func-tional integration of multi-level overheating warning and small deformation monitoring.展开更多
Battery safety is influenced by various factors,with thermal runaway being one of the most significant concerns.While most studies have concentrated on developing one-time,self-activating mechanism for thermal protect...Battery safety is influenced by various factors,with thermal runaway being one of the most significant concerns.While most studies have concentrated on developing one-time,self-activating mechanism for thermal protection,such as temperature-responsive electrodes,and thermal-shutdown separators,these methods only provide irreversible protection.Recently,reversible temperature-sensitive electrolytes have emerged as promising alternatives,offering both thermo-reversibility and self-protective properties.However,further research is crucial to fully understand these thermal-shutdown electrolytes.In this study,we propose lower critical solution temperature(LCST)phase behavior poly(benzyl methacrylate)/imidazolium-based ionic liquid mixtures to prepare temperature-sensitive electrolytes that provide reversible thermal shutdown protection of batteries.This electrolyte features an appropriate protection temperature(~105℃)and responds quickly within a 1 min at 105℃,causing cells to hardly discharge as the voltage suddenly drops to 3.38 V,and providing efficient thermal shutdown protection within 30 min.Upon cooling back to room temperature,the battery regains its original performance.Additionally,the electrolyte exhibits excellent cycling stability with the capacity retention of the battery is 91.6%after 500 cycles.This work provides a viable solution for preventing batteries from thermal runaway triggered by overheating.展开更多
Thermal barrier coatings(TBC)on superalloy blade/vane enable an increase in turbine inlet temperature(TIT)and aero-engine efficiency.However,the deposition of dust on TBC significantly ablates superalloys and becomes ...Thermal barrier coatings(TBC)on superalloy blade/vane enable an increase in turbine inlet temperature(TIT)and aero-engine efficiency.However,the deposition of dust on TBC significantly ablates superalloys and becomes a bottleneck for advanced engine development.This paper presents a comprehensive mod-eling approach,based on an experiment involving dust deposition on a TBC-coated substrate,aimed at understanding the fundamental cause of substrate ablation.The results show that a significant increase in surface roughness is obtained experimentally with dust accumulation.The temperature field within the TBC-substrate system is disturbed by surface roughening.Consequently,the film cooling is seriously destroyed.While the dust accumulated on the TBC surface also contributes to heat insulation by increas-ing the effective TBC thickness,localized overheating of the substrate occurs and then leads to ablation and premature failure of the substrate.This elucidation of the overheating mechanism could inform the development of strategies to resist dust accumulation in advanced aero engines.展开更多
Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin re...Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin responsible for the variation of properties remains poorly understood.In the present work,we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins.Specifically,we quenched the melt at different temperatures ranging from 1.1Tl to 1.5Tl(Tl is the liquidus temperature)to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating.We found that glass transition temperature,Tg,increases by as much as 36 K,and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5Tl.The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys.The incorporated oxygen and silicon can both enhance the interactions between atoms,which renders the cooperative rearrangements of atoms difficult,and thus enhances the kinetic stability of the MGs.展开更多
The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with ...The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx（x=10, 12） alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.展开更多
During the Covid-19 pandemic in Serbia on March 6.to 03.04.2020.I cured 41 cases with a very severe clinical picture of influenza or possibly Covid-19.At that time,the Health Center in Sjenica did not have the materia...During the Covid-19 pandemic in Serbia on March 6.to 03.04.2020.I cured 41 cases with a very severe clinical picture of influenza or possibly Covid-19.At that time,the Health Center in Sjenica did not have the material for the diagnosis of Covid-19,and the patients refused to go to the neighboring Health Center because of the fear that caused sudden deaths.In my scientific work:“The role of cold in the origin and development of diseases with special review of some diseases of the respiratory system-treatment and prevention”,I proved the effect of cold and overheating on all organs and effective treatment.Under the effect of cooling,vasoconstriction,impaired circulation and impaired metabolism occur.Macrophage motility is reduced,phagocytes are weakened,ingestion,which causes easy implantation of the virus in the lungs.All the viral infections I followed for more than 35 years passed with mild symptoms if there was no previous cold or during the illness,even with the highly infectious Mexican flu(A/H1N1)and influenza.Patients with Covid-19 reported minimal,minor or more intense colds,which also determined the severity of the clinical picture.展开更多
The subject of this study is the oxidation of fuel rod cladding made of material Zr1Nb(0.1% O) in steam at temperatures in the range of 660℃ to 1200℃ with a surface in the initial state (after manufacturing - grindi...The subject of this study is the oxidation of fuel rod cladding made of material Zr1Nb(0.1% O) in steam at temperatures in the range of 660℃ to 1200℃ with a surface in the initial state (after manufacturing - grinding) and after additional chemical etching. The changes in the microstructure of tubes due to the interaction with steam were investigated. A comparison was made between the oxidation rate of this material (weight gain) and the data on the oxidation of other alloys for nuclear power plants. The oxidation rate of Zr1Nb(0.1% O) is close to the oxidation rate of other zirconium alloys. It is shown that after chemical treatment of the surface of the samples there is a more even growth of oxide films, and they have a smaller thickness for the same time of exposure than after mechanical grinding. Surface treatment before oxidation also affects the change of microstructure of samples when heated to high temperatures.展开更多
On June 19th,2017,the registration system of ITMA ASIA＋CITME 2018 came online officially.In the past five months,the exhibition recruitment work has obtained the general concentration of the industry.What is the bigg...On June 19th,2017,the registration system of ITMA ASIA＋CITME 2018 came online officially.In the past five months,the exhibition recruitment work has obtained the general concentration of the industry.What is the biggest difference of this exhibition with the previous ones？What will the audiences and exhibitors get from this exhibition？展开更多
Through the long time track examination and disintegration to SF6 circuit breaker, we obtain the massive monitor data and massive pictures. The criteria of resuming insulation discharge failure conforming to CSO2/CH2S...Through the long time track examination and disintegration to SF6 circuit breaker, we obtain the massive monitor data and massive pictures. The criteria of resuming insulation discharge failure conforming to CSO2/CH2S>7, is quite broad to SO2 and the H2S concentration permission. Even if it reaches 100μL/L, it will not be in danger immediately to the safe operation of equipment. We may plan, arrange, and overhaul calmly. When obtaining the bare conductor overheating failure, it has not involved the resuming insulation. We may use the resuming insulation discharge failure criterion.展开更多
An increase in ambient air temperature due to climate change can adversely affect indoor thermal conditions,particularly in heritage-listed dwellings,as renovation efforts may be limited by preservation constraints,po...An increase in ambient air temperature due to climate change can adversely affect indoor thermal conditions,particularly in heritage-listed dwellings,as renovation efforts may be limited by preservation constraints,potentially leading to indoor overheating for occupants.Incorporating heritage-listed dwellings into the climate change adaptation strategies is essential.Heritage-listed dwellings exhibit varying preservation constraints,with character-defining elements differing across cases.A literature review indicates a deficiency in research regarding climate change adaptation for lilong houses,which are two-to three-storey terrace houses featuring timber-brick structures,predominantly constructed in late 19th and early 20th century Shanghai,and recognised as significant urban heritage of the city.Through building energy simulations,this article examines the climate change adaptation of heritage-listed apartment-style lilong houses in Shanghai.Overheating hours and degree hours are utilised to assess indoor overheating conditions.Three scenarios for the preservation of the building envelope are proposed:(1)preservation of walls,(2)preservation of windows,(3)preservation of the roof.There are five categories of climate change adaptation measures.The findings indicate that substantial reductions can be attained by implementing a single preservation scenario customised to the character-defining elements and preservation constraints of heritage-listed dwellings.The most significant decrease in the number of overheating hours is observed in the wall preservation scenario,with a reduction of 69%,followed by a 53%reduction in the roof preservation scenario and a 31%reduction in the window preservation scenario.The proposed preservation scenarios enable the improvement in building indoor thermal conditions without compromising heritage preservation.展开更多
Evidence indicates that improvement of thermal performance of building envelope has the potential for aggravating the indoor overheating risk in summer. On the other hand, evolving building standards continue to stren...Evidence indicates that improvement of thermal performance of building envelope has the potential for aggravating the indoor overheating risk in summer. On the other hand, evolving building standards continue to strengthen the requirements for thermal performance to achieve the energy-saving target. Therefore, this study quantifies the interaction effect between building standards-oriented building design, heating energy demand in winter, and indoor overheating risk in summer. Building databases with different energy efficiency levels are generated using a randomly generated method. Uncertain variables include not only 13 design parameters but also the running state of natural ventilation and external shading. The indoor overheating risk is assessed in terms of severity and duration. Finally, a multi-objective optimization model integrating metamodels and the non-dominated sorting genetic algorithm is proposed to balance heating energy demand in winter and indoor overheating risk in summer. Results indicate that building standards tend to aggravate overheating risk in summer: the duration and severity of high-performance buildings increased by 40.6% and 24.2% than that of conventional-performance buildings. However, window ventilation could offset the adverse effect, and mitigation of duration and severity can be up to 85.2% and 62.1% for high-performance buildings. Window ventilation can weaken the conflict between heating energy demand in winter and overheating risk in summer. As heating energy demand increased from 6.1 to 67.3 kWh/m^(2), the overheating risk changes little that the duration of overheating risk decreased from 17.5% to 15.6% and severity decreased from 8.7 ℃ to 8.3 ℃.展开更多
In the simulation of building overheating risks,the use of typical meteorological years(TMY)can greatly reduce the simulation workload and accurately reflect the distribution of simulation results according to the wea...In the simulation of building overheating risks,the use of typical meteorological years(TMY)can greatly reduce the simulation workload and accurately reflect the distribution of simulation results according to the weather conditions over a given period.However,all meteorological parameters in most current TMY methods use a uniform weighting factor which may make the simulation results against the actual simulation results of the period and negatively affect the accuracy of the evaluation results.In addition to differences in climate characteristics between climate zones,the sensitivity of different simulation results to external parameters will also be different.Therefore,a TMY method based on the Finkelstein-Schafer statistical method is proposed,which considers the climatic characteristics of different regions and the correlation with the output parameters of indoor simulation to select the typical month.The proposed method is demonstrated in the three future scenarios for the three cities in different climate zones in China.The results show that the traditional TMY method has an overestimated weight of solar radiation and wind speed and an undervalued weight of dry bulb temperature when indoor temperature-related indicators are the output target.Compared with the traditional TMY method,the TMY generated by the improved method is closer to the distribution characteristics of the long-term outdoor weather data.Furthermore,when using the improved TMY data to evaluate the overheating performance of the passive residential buildings,the difference of the results of the unmet degree hours,indoor overheating degree,and the overheating escalation factor between the long-term projected data and the TMY data can be reduced by 63%–67%compared with the traditional TMY data.展开更多
Solar water heating systems have been widely used around the world.However,exposure to sunlight can overheat the device,affecting the efficiency and durability of the system.This article proposes an adaptive deck cont...Solar water heating systems have been widely used around the world.However,exposure to sunlight can overheat the device,affecting the efficiency and durability of the system.This article proposes an adaptive deck controller that protects the system from overheating without compromising the availability of domestic hot water.Solar water heaters are considered one of the most effective ways to reduce a home’s carbon footprint.They are a renewable energy source that reduces reliance on fossil fuels and saves money.Thus,this paper aims to develop a dynamic cover for solar water heaters that prevent overheating using an artificial neural network to optimize the design of control systems.Based on a self-organizing map network,the controller automatically adjusts the temperature of the solar collector through a fabric screen covering the main subsystems,depending on many parameters such as weather conditions,collector temperature and domestic hot water depending on demand.A suggested technique of four different shade percentages(0%,20%,25%or 32%)can avoid overheating and maintain the amount of hot water the home needs.Although renewable energy is free,proper controls are required to ensure maximum efficiency or proper use.In addition,the control of renewable energy leads to longer service life.展开更多
This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from d...This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.展开更多
Numerous decision-makers in politics,science,and business worldwide have acknowledged that hydrogen H_(2) will become one of the most important energy sources of the 21st century if the desired energy transition to ca...Numerous decision-makers in politics,science,and business worldwide have acknowledged that hydrogen H_(2) will become one of the most important energy sources of the 21st century if the desired energy transition to carbon-free energy sources is to be taken seriously.Nevertheless,this transition in general and the introduction of H_(2) in particular is still progressing far too slowly.There are now countless projects worldwide,including several worth billions of US dollars,but we are still waiting for the breakthrough.There seem to be various reasons for this,not just one single or most important one.Purpose:In the overall context of global earth overheating(often downplayed as“climate change”),hydrogen H_(2) will undoubtedly play a decisive role as of now.The paper aims to identify the key challenges and propose solutions for establishing a sustainable value chain for market penetration of H_(2).Design/methodology/approach:This paper aims to shed light on the current situation using freely accessible publications from global management consultancies and the German government,as well as critical reporting.The problem of human behavior is also explained by the Novak Triangle.Findings:Most people have come to understand that anthropogenic global overheating can only be solved by new technologies(which cost money,time,and behavioral change)in production and application.Hydrogen H_(2) appears to be an essential part of the desired solution.Nevertheless,there are currently still numerous challenges and also concrete concerns worldwide,which partially cast the implementation in a questionable light.The findings suggest that establishing a demand and supply of H_(2) needs a comprehensive infrastructure,circular economy principles,and changes in consumer behavior and policy frameworks.The paper proposes solutions for addressing these challenges.Affected countries:The situation described here relates to Germany and the EU countries,but it is likely to be comparable,or at least similar,for many industrialized countries.The challenges and solutions proposed in this paper are relevant to countries worldwide that are transitioning to sustainable energy and transportation systems.Research/future/practical implications:As of 2024,it must be stated that the implementation of H_(2) is still progressing far too slowly,even in the“model country”Germany.There are still problems and stalling in many places.The biggest challenge seems to be the problem:without demand,there is no supply;without supply,there is no demand.This can then best be achieved with simple“out-of-the-box”solutions in mindset(see Novak triangle).The research implications of this paper include the need for further research on the challenges of establishing a sustainable value chain and the effectiveness of the proposed solutions.The future implications of this paper include the importance of establishing a sustainable value chain to mitigate climate change and reduce dependence on fossil fuels.The core point will become the collaboration across the entire value chain to establish a sustainable infrastructure for sustainable energy and transportation systems.Originality/value:Currently,there are virtually no scientific books that would present the overall context of the challenges.Therefore,only current surveys,market volumes,and challenges in environmental and working conditions can be described here.This paper contributes to the literature by analyzing the challenges of establishing a market model for hydrogen H_(2).The paper proposes solutions for addressing these challenges and shows difficulties.It provides valuable insights for policymakers,industry stakeholders,and researchers working towards a sustainable energy future.展开更多
A concept of ensemble averaged stellar reactors is developed to study the dynamics of processes occurring in stars, allocated in the ~200 pc solar neighborhood. According to the effective temperature value, four stell...A concept of ensemble averaged stellar reactors is developed to study the dynamics of processes occurring in stars, allocated in the ~200 pc solar neighborhood. According to the effective temperature value, four stellar classes are identified, for which the correlation coefficients and standard deviation are counted. The theory of the buoyancy terrestial elements is generalized to stellar systems. It was suggested that stars are over-heated due to the shift parameters of the nuclear processes occurring inside the stars, which leads to the synthesis of transuranium elements until the achievement of a critical nuclear mass and star explosion. The heavy transuranium elements sink downward and are concentrated in the stellar depth layers. The physical explanation of the existence of the critical Chandrasekhar star limit has been offered. Based on the spatial analysis of overheated stars, it was suggested that the withdrawal of the stellar reactor from the equilibrium state is a consequence of extragalactic compression inside the galaxy arm due to the arm spirality (not to be confused with the spirality of the galaxy itself).展开更多
Aero-engine turbine blades may suffer overheating during service,which can result in severe microstructural and mechanical degradation within tens of seconds.In this study,the thermal cycling creep under(950℃/15 min+...Aero-engine turbine blades may suffer overheating during service,which can result in severe microstructural and mechanical degradation within tens of seconds.In this study,the thermal cycling creep under(950℃/15 min+1100℃/1 min)-100 MPa was performed on a directionally solidified superalloy,DZ125.The effects of overheating and thermal cycling on the creep properties were evaluated in terms of creep behavior and microstructural evolution against isothermally crept specimens under 950℃/100 MPa,950℃/270 MPa,and 1100℃/100 MPa.The results indicated that the thermal cycling creep life was reduced dramatically compared to the isothermal creep under 950℃/100 MPa.The plastic creep deformation mainly occurred during the overheating stage during the thermal cycling creep.The thermal cycling creep curve exhibited three stages,similar to the 1100℃isothermal creep,but its minimum creep rate occurred at a lower creep strain.The overheating events caused severe microstructural degradation,such as substantial dissolution ofγ'phase,earlier formation of raftedγ'microstructure,widening of theγchannels,and instability of the interfacial dislocation networks.This microstructural degradation was the main reason for the dramatic decrease in thermal cycling creep life,as the thermal cycling promoted more dislocations to cut intoγ'phase and more cracks to initiate at grain boundaries,carbides,and residual eutectic pools.This study underlines the importance of evaluating the thermal cycling creep properties of superalloys to be used as turbine blades and provides insights into the effect of thermal cycling on directionally solidified superalloys for component design.展开更多
Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan coolin...Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan cooling system (ECHDFCS). The system was applied to a 50-wheel loader. We carried out the coolant temperature simulation using fluid modeling software FLOWMASTER, followed by laboratory experiments and road tests. The results show that ECHDFCS can adjust the cooling capability of the system automatically based on machine heat dissipation requirements. The coolant temperature is consequently remained within an appropriate range. The simulation results are consistent with the experiment results when the experiment is performed on the plain, but are different from the road tests in some investigated parameters on the plateau.展开更多
Abstract: In the occurrence of arc discharges, spark discharges, corona discharges and overheated faults in electrical equipment, SF 6would be decomposed to complicated byproducts, such as SO2 , H2S and HF. Analyzing ...Abstract: In the occurrence of arc discharges, spark discharges, corona discharges and overheated faults in electrical equipment, SF 6would be decomposed to complicated byproducts, such as SO2 , H2S and HF. Analyzing these byproducts is an effective method to judge the internal operation condition of electric equipment. In order to study characters of SF6byproducts at different temperature of overheated faults in the electric equipment, a series of overheated faults of electric equipment were simulated. SF6is very stable and not significantly decomposed at 200oC, 250oC and 300oC. SF6is significantly decomposed to SO2, H2S and HF at 350oC. The concentration of SO2, H2S and HF was 7.2, 1.6 and 1.9 μL/L after heating for 5 hours in environment of SF6with 3616 μL/L water, and it was increased to 23.0, 3.0 and 1.2 μL/L 3 hours later. SF6is more easily to be decomposed and decomposed more rapidly at higher temperature. The concentration of SO2, H2S and HF was 62.2, 15.6 and 3.6 μL/L after heating for 5 hours in environment of SF6with 4064 μL/L water, and it was increased to 91.4, 25.2 and 2.3 μL/L 3 hours later. SF6will be decomposed to format HF, which is strongly corrosive and whose concentration is likely to decrease when it is above a certain concentration.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51503158)Key R&D Program of Hubei Province (No.2023BAB104)Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan Province(No.PLN2024-08)
文摘The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overheating or localized strain are of great value for the safe use of lithium batteries or film capacitors;however,this function usually requires a system of multiple complex sensors.The realization of the above multiple hazards using a single sensor for monitoring and alarm functions has not been reported.Here,we exploit the thermally induced conductivity and modulus change during solid-liquid conversion of low melting point polyalloys to modulate the electronic relaxation polariza-tion and interfacial polarization in the composites for dielectric switching,and the reduction of alloy particle spacing during bending/compres-sive strain can be used to generate switchable tunneling effects for insulator-conductor transition.By synergizing dielectric switching and insula-tor-conductor transition,the final flexible thermoplastic polyurethane elastomer/low-melting-point polyalloy composite film achieves the func-tional integration of multi-level overheating warning and small deformation monitoring.
基金funded by the National Natural Science Foundation of China(no.22075155)the Zhejiang Provincial Natural Science Foundation of China(No.LY24B030002)+2 种基金Ningbo Natural Science Foundation(2023J089)the China Scholarship Council(CSC)the Ningbo Science and Technology Bureau(2024QL036).
文摘Battery safety is influenced by various factors,with thermal runaway being one of the most significant concerns.While most studies have concentrated on developing one-time,self-activating mechanism for thermal protection,such as temperature-responsive electrodes,and thermal-shutdown separators,these methods only provide irreversible protection.Recently,reversible temperature-sensitive electrolytes have emerged as promising alternatives,offering both thermo-reversibility and self-protective properties.However,further research is crucial to fully understand these thermal-shutdown electrolytes.In this study,we propose lower critical solution temperature(LCST)phase behavior poly(benzyl methacrylate)/imidazolium-based ionic liquid mixtures to prepare temperature-sensitive electrolytes that provide reversible thermal shutdown protection of batteries.This electrolyte features an appropriate protection temperature(~105℃)and responds quickly within a 1 min at 105℃,causing cells to hardly discharge as the voltage suddenly drops to 3.38 V,and providing efficient thermal shutdown protection within 30 min.Upon cooling back to room temperature,the battery regains its original performance.Additionally,the electrolyte exhibits excellent cycling stability with the capacity retention of the battery is 91.6%after 500 cycles.This work provides a viable solution for preventing batteries from thermal runaway triggered by overheating.
基金National Natural Science Foundation of China(No.51901175)China Postdoctoral Science Foundation Grant(Nos.2020T130499 and 2019M653602)HPC platform in Xi'an Jiaotong University.
文摘Thermal barrier coatings(TBC)on superalloy blade/vane enable an increase in turbine inlet temperature(TIT)and aero-engine efficiency.However,the deposition of dust on TBC significantly ablates superalloys and becomes a bottleneck for advanced engine development.This paper presents a comprehensive mod-eling approach,based on an experiment involving dust deposition on a TBC-coated substrate,aimed at understanding the fundamental cause of substrate ablation.The results show that a significant increase in surface roughness is obtained experimentally with dust accumulation.The temperature field within the TBC-substrate system is disturbed by surface roughening.Consequently,the film cooling is seriously destroyed.While the dust accumulated on the TBC surface also contributes to heat insulation by increas-ing the effective TBC thickness,localized overheating of the substrate occurs and then leads to ablation and premature failure of the substrate.This elucidation of the overheating mechanism could inform the development of strategies to resist dust accumulation in advanced aero engines.
基金The work was financially supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0703600,2021YFA0716302,and 2021YFA0718703)the National Natural Science Foundation of China(Grant Nos.51825104 and 52192602)China Postdoctoral Science Foundation(Grant No.2022T150691).
文摘Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin responsible for the variation of properties remains poorly understood.In the present work,we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins.Specifically,we quenched the melt at different temperatures ranging from 1.1Tl to 1.5Tl(Tl is the liquidus temperature)to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating.We found that glass transition temperature,Tg,increases by as much as 36 K,and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5Tl.The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys.The incorporated oxygen and silicon can both enhance the interactions between atoms,which renders the cooperative rearrangements of atoms difficult,and thus enhances the kinetic stability of the MGs.
基金Projects(51174121,51274125)supported by the National Natural Science Foundation of ChinaProject(2010R50016-30)supported by Zhejiang Province Science and Technology Innovation Team of Key Projects,ChinaProject supported by the K.C.Wong Magna Fund of Ningbo University,China
文摘The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx（x=10, 12） alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.
文摘During the Covid-19 pandemic in Serbia on March 6.to 03.04.2020.I cured 41 cases with a very severe clinical picture of influenza or possibly Covid-19.At that time,the Health Center in Sjenica did not have the material for the diagnosis of Covid-19,and the patients refused to go to the neighboring Health Center because of the fear that caused sudden deaths.In my scientific work:“The role of cold in the origin and development of diseases with special review of some diseases of the respiratory system-treatment and prevention”,I proved the effect of cold and overheating on all organs and effective treatment.Under the effect of cooling,vasoconstriction,impaired circulation and impaired metabolism occur.Macrophage motility is reduced,phagocytes are weakened,ingestion,which causes easy implantation of the virus in the lungs.All the viral infections I followed for more than 35 years passed with mild symptoms if there was no previous cold or during the illness,even with the highly infectious Mexican flu(A/H1N1)and influenza.Patients with Covid-19 reported minimal,minor or more intense colds,which also determined the severity of the clinical picture.
文摘The subject of this study is the oxidation of fuel rod cladding made of material Zr1Nb(0.1% O) in steam at temperatures in the range of 660℃ to 1200℃ with a surface in the initial state (after manufacturing - grinding) and after additional chemical etching. The changes in the microstructure of tubes due to the interaction with steam were investigated. A comparison was made between the oxidation rate of this material (weight gain) and the data on the oxidation of other alloys for nuclear power plants. The oxidation rate of Zr1Nb(0.1% O) is close to the oxidation rate of other zirconium alloys. It is shown that after chemical treatment of the surface of the samples there is a more even growth of oxide films, and they have a smaller thickness for the same time of exposure than after mechanical grinding. Surface treatment before oxidation also affects the change of microstructure of samples when heated to high temperatures.
文摘On June 19th,2017,the registration system of ITMA ASIA＋CITME 2018 came online officially.In the past five months,the exhibition recruitment work has obtained the general concentration of the industry.What is the biggest difference of this exhibition with the previous ones？What will the audiences and exhibitors get from this exhibition？
文摘Through the long time track examination and disintegration to SF6 circuit breaker, we obtain the massive monitor data and massive pictures. The criteria of resuming insulation discharge failure conforming to CSO2/CH2S>7, is quite broad to SO2 and the H2S concentration permission. Even if it reaches 100μL/L, it will not be in danger immediately to the safe operation of equipment. We may plan, arrange, and overhaul calmly. When obtaining the bare conductor overheating failure, it has not involved the resuming insulation. We may use the resuming insulation discharge failure criterion.
基金financially supported by the China Scholarship Council(Grant No.201606130059).
文摘An increase in ambient air temperature due to climate change can adversely affect indoor thermal conditions,particularly in heritage-listed dwellings,as renovation efforts may be limited by preservation constraints,potentially leading to indoor overheating for occupants.Incorporating heritage-listed dwellings into the climate change adaptation strategies is essential.Heritage-listed dwellings exhibit varying preservation constraints,with character-defining elements differing across cases.A literature review indicates a deficiency in research regarding climate change adaptation for lilong houses,which are two-to three-storey terrace houses featuring timber-brick structures,predominantly constructed in late 19th and early 20th century Shanghai,and recognised as significant urban heritage of the city.Through building energy simulations,this article examines the climate change adaptation of heritage-listed apartment-style lilong houses in Shanghai.Overheating hours and degree hours are utilised to assess indoor overheating conditions.Three scenarios for the preservation of the building envelope are proposed:(1)preservation of walls,(2)preservation of windows,(3)preservation of the roof.There are five categories of climate change adaptation measures.The findings indicate that substantial reductions can be attained by implementing a single preservation scenario customised to the character-defining elements and preservation constraints of heritage-listed dwellings.The most significant decrease in the number of overheating hours is observed in the wall preservation scenario,with a reduction of 69%,followed by a 53%reduction in the roof preservation scenario and a 31%reduction in the window preservation scenario.The proposed preservation scenarios enable the improvement in building indoor thermal conditions without compromising heritage preservation.
基金This research has been supported by the“National Key R&D Program of China”(Grant No.2016YFC0700100)The U.S.authors recognize Lawrence Berkeley National Laboratory’s support from the U.S.Department of Energy under Contract No.DE-AC02-05CH11231 and support from the Energy FoundationThe U.S.Government retains a non-exclusive,paid-up,irrevocable,world-wide license to publish or reproduce the published form of this manuscript,or allow others to do so,for U.S.Government purposes.
文摘Evidence indicates that improvement of thermal performance of building envelope has the potential for aggravating the indoor overheating risk in summer. On the other hand, evolving building standards continue to strengthen the requirements for thermal performance to achieve the energy-saving target. Therefore, this study quantifies the interaction effect between building standards-oriented building design, heating energy demand in winter, and indoor overheating risk in summer. Building databases with different energy efficiency levels are generated using a randomly generated method. Uncertain variables include not only 13 design parameters but also the running state of natural ventilation and external shading. The indoor overheating risk is assessed in terms of severity and duration. Finally, a multi-objective optimization model integrating metamodels and the non-dominated sorting genetic algorithm is proposed to balance heating energy demand in winter and indoor overheating risk in summer. Results indicate that building standards tend to aggravate overheating risk in summer: the duration and severity of high-performance buildings increased by 40.6% and 24.2% than that of conventional-performance buildings. However, window ventilation could offset the adverse effect, and mitigation of duration and severity can be up to 85.2% and 62.1% for high-performance buildings. Window ventilation can weaken the conflict between heating energy demand in winter and overheating risk in summer. As heating energy demand increased from 6.1 to 67.3 kWh/m^(2), the overheating risk changes little that the duration of overheating risk decreased from 17.5% to 15.6% and severity decreased from 8.7 ℃ to 8.3 ℃.
基金The first author gratefully acknowledges the financial support from the Chinese Scholarship Council(CSC No.202007000086).
文摘In the simulation of building overheating risks,the use of typical meteorological years(TMY)can greatly reduce the simulation workload and accurately reflect the distribution of simulation results according to the weather conditions over a given period.However,all meteorological parameters in most current TMY methods use a uniform weighting factor which may make the simulation results against the actual simulation results of the period and negatively affect the accuracy of the evaluation results.In addition to differences in climate characteristics between climate zones,the sensitivity of different simulation results to external parameters will also be different.Therefore,a TMY method based on the Finkelstein-Schafer statistical method is proposed,which considers the climatic characteristics of different regions and the correlation with the output parameters of indoor simulation to select the typical month.The proposed method is demonstrated in the three future scenarios for the three cities in different climate zones in China.The results show that the traditional TMY method has an overestimated weight of solar radiation and wind speed and an undervalued weight of dry bulb temperature when indoor temperature-related indicators are the output target.Compared with the traditional TMY method,the TMY generated by the improved method is closer to the distribution characteristics of the long-term outdoor weather data.Furthermore,when using the improved TMY data to evaluate the overheating performance of the passive residential buildings,the difference of the results of the unmet degree hours,indoor overheating degree,and the overheating escalation factor between the long-term projected data and the TMY data can be reduced by 63%–67%compared with the traditional TMY data.
基金The authors would like to thank the Higher Center for Research(HCR)of the Holy Spirit University of Kaslik(USEK)the National Council for Scientific Research in Lebanon(CNRS-L)for funding this project。
文摘Solar water heating systems have been widely used around the world.However,exposure to sunlight can overheat the device,affecting the efficiency and durability of the system.This article proposes an adaptive deck controller that protects the system from overheating without compromising the availability of domestic hot water.Solar water heaters are considered one of the most effective ways to reduce a home’s carbon footprint.They are a renewable energy source that reduces reliance on fossil fuels and saves money.Thus,this paper aims to develop a dynamic cover for solar water heaters that prevent overheating using an artificial neural network to optimize the design of control systems.Based on a self-organizing map network,the controller automatically adjusts the temperature of the solar collector through a fabric screen covering the main subsystems,depending on many parameters such as weather conditions,collector temperature and domestic hot water depending on demand.A suggested technique of four different shade percentages(0%,20%,25%or 32%)can avoid overheating and maintain the amount of hot water the home needs.Although renewable energy is free,proper controls are required to ensure maximum efficiency or proper use.In addition,the control of renewable energy leads to longer service life.
基金supported by the European Union through the European Regional Development Fundthe“Reducing the Environmental Impact of Buildings through Improvements of Energy Performance,AR12059”(financed by SA Archimedes)IUT1-15 project“Nearly-Zero Energy Solutions and Their Implementation on Deep Renovation of Buildings”(financed by the Estonian Research Council).
文摘This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.
文摘Numerous decision-makers in politics,science,and business worldwide have acknowledged that hydrogen H_(2) will become one of the most important energy sources of the 21st century if the desired energy transition to carbon-free energy sources is to be taken seriously.Nevertheless,this transition in general and the introduction of H_(2) in particular is still progressing far too slowly.There are now countless projects worldwide,including several worth billions of US dollars,but we are still waiting for the breakthrough.There seem to be various reasons for this,not just one single or most important one.Purpose:In the overall context of global earth overheating(often downplayed as“climate change”),hydrogen H_(2) will undoubtedly play a decisive role as of now.The paper aims to identify the key challenges and propose solutions for establishing a sustainable value chain for market penetration of H_(2).Design/methodology/approach:This paper aims to shed light on the current situation using freely accessible publications from global management consultancies and the German government,as well as critical reporting.The problem of human behavior is also explained by the Novak Triangle.Findings:Most people have come to understand that anthropogenic global overheating can only be solved by new technologies(which cost money,time,and behavioral change)in production and application.Hydrogen H_(2) appears to be an essential part of the desired solution.Nevertheless,there are currently still numerous challenges and also concrete concerns worldwide,which partially cast the implementation in a questionable light.The findings suggest that establishing a demand and supply of H_(2) needs a comprehensive infrastructure,circular economy principles,and changes in consumer behavior and policy frameworks.The paper proposes solutions for addressing these challenges.Affected countries:The situation described here relates to Germany and the EU countries,but it is likely to be comparable,or at least similar,for many industrialized countries.The challenges and solutions proposed in this paper are relevant to countries worldwide that are transitioning to sustainable energy and transportation systems.Research/future/practical implications:As of 2024,it must be stated that the implementation of H_(2) is still progressing far too slowly,even in the“model country”Germany.There are still problems and stalling in many places.The biggest challenge seems to be the problem:without demand,there is no supply;without supply,there is no demand.This can then best be achieved with simple“out-of-the-box”solutions in mindset(see Novak triangle).The research implications of this paper include the need for further research on the challenges of establishing a sustainable value chain and the effectiveness of the proposed solutions.The future implications of this paper include the importance of establishing a sustainable value chain to mitigate climate change and reduce dependence on fossil fuels.The core point will become the collaboration across the entire value chain to establish a sustainable infrastructure for sustainable energy and transportation systems.Originality/value:Currently,there are virtually no scientific books that would present the overall context of the challenges.Therefore,only current surveys,market volumes,and challenges in environmental and working conditions can be described here.This paper contributes to the literature by analyzing the challenges of establishing a market model for hydrogen H_(2).The paper proposes solutions for addressing these challenges and shows difficulties.It provides valuable insights for policymakers,industry stakeholders,and researchers working towards a sustainable energy future.
文摘A concept of ensemble averaged stellar reactors is developed to study the dynamics of processes occurring in stars, allocated in the ~200 pc solar neighborhood. According to the effective temperature value, four stellar classes are identified, for which the correlation coefficients and standard deviation are counted. The theory of the buoyancy terrestial elements is generalized to stellar systems. It was suggested that stars are over-heated due to the shift parameters of the nuclear processes occurring inside the stars, which leads to the synthesis of transuranium elements until the achievement of a critical nuclear mass and star explosion. The heavy transuranium elements sink downward and are concentrated in the stellar depth layers. The physical explanation of the existence of the critical Chandrasekhar star limit has been offered. Based on the spatial analysis of overheated stars, it was suggested that the withdrawal of the stellar reactor from the equilibrium state is a consequence of extragalactic compression inside the galaxy arm due to the arm spirality (not to be confused with the spirality of the galaxy itself).
基金supported by the“National Key Research and Development Program of China(Grant No.2016YFB0701403)”the“National Natural Science Foundation of China(Grant Nos.51631008 and 91860201)”+1 种基金the“111 Project(No.B170003)”financial support to the reported work.Stoichko Antonov would like to acknowledge financial support from the Alexander von Humboldt Foundation。
文摘Aero-engine turbine blades may suffer overheating during service,which can result in severe microstructural and mechanical degradation within tens of seconds.In this study,the thermal cycling creep under(950℃/15 min+1100℃/1 min)-100 MPa was performed on a directionally solidified superalloy,DZ125.The effects of overheating and thermal cycling on the creep properties were evaluated in terms of creep behavior and microstructural evolution against isothermally crept specimens under 950℃/100 MPa,950℃/270 MPa,and 1100℃/100 MPa.The results indicated that the thermal cycling creep life was reduced dramatically compared to the isothermal creep under 950℃/100 MPa.The plastic creep deformation mainly occurred during the overheating stage during the thermal cycling creep.The thermal cycling creep curve exhibited three stages,similar to the 1100℃isothermal creep,but its minimum creep rate occurred at a lower creep strain.The overheating events caused severe microstructural degradation,such as substantial dissolution ofγ'phase,earlier formation of raftedγ'microstructure,widening of theγchannels,and instability of the interfacial dislocation networks.This microstructural degradation was the main reason for the dramatic decrease in thermal cycling creep life,as the thermal cycling promoted more dislocations to cut intoγ'phase and more cracks to initiate at grain boundaries,carbides,and residual eutectic pools.This study underlines the importance of evaluating the thermal cycling creep properties of superalloys to be used as turbine blades and provides insights into the effect of thermal cycling on directionally solidified superalloys for component design.
基金Funded by the Innovation Foundation of Guangzhou, P. R. China (No. 2005V42C0021)
文摘Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan cooling system (ECHDFCS). The system was applied to a 50-wheel loader. We carried out the coolant temperature simulation using fluid modeling software FLOWMASTER, followed by laboratory experiments and road tests. The results show that ECHDFCS can adjust the cooling capability of the system automatically based on machine heat dissipation requirements. The coolant temperature is consequently remained within an appropriate range. The simulation results are consistent with the experiment results when the experiment is performed on the plain, but are different from the road tests in some investigated parameters on the plateau.
文摘Abstract: In the occurrence of arc discharges, spark discharges, corona discharges and overheated faults in electrical equipment, SF 6would be decomposed to complicated byproducts, such as SO2 , H2S and HF. Analyzing these byproducts is an effective method to judge the internal operation condition of electric equipment. In order to study characters of SF6byproducts at different temperature of overheated faults in the electric equipment, a series of overheated faults of electric equipment were simulated. SF6is very stable and not significantly decomposed at 200oC, 250oC and 300oC. SF6is significantly decomposed to SO2, H2S and HF at 350oC. The concentration of SO2, H2S and HF was 7.2, 1.6 and 1.9 μL/L after heating for 5 hours in environment of SF6with 3616 μL/L water, and it was increased to 23.0, 3.0 and 1.2 μL/L 3 hours later. SF6is more easily to be decomposed and decomposed more rapidly at higher temperature. The concentration of SO2, H2S and HF was 62.2, 15.6 and 3.6 μL/L after heating for 5 hours in environment of SF6with 4064 μL/L water, and it was increased to 91.4, 25.2 and 2.3 μL/L 3 hours later. SF6will be decomposed to format HF, which is strongly corrosive and whose concentration is likely to decrease when it is above a certain concentration.
