Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Bas...Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Based on the field study result, by using the simulation sol, ware, THERB, the effectiveness of the crawlspace warm air heating system has been examined. The effect of the factors, such as the wind amount circulating between crawlspace and indoor space, foundation insulation condition, and heat amount into the crawlspace, on the indoor thermal environment has been analyzed. Based on these analyses, the measured crawlspace heating system can make the average temperature of the living room above 20℃. These two houses have excellent thermal environment. According to the simulating result, heat amount input into crawlspace, which can make comfortable indoor thermal environment, for every month in heating period has been roughly concluded, and they are 600 W in December and March and 800 W in February and January, respectively.展开更多
In the scope of material science, it is well understood that mechanical behavior of a material is temperature dependent. The converse is also true and for specific loading cases contributes to a unique thermal failure...In the scope of material science, it is well understood that mechanical behavior of a material is temperature dependent. The converse is also true and for specific loading cases contributes to a unique thermal failure mechanism known as “heat explosion”. The goal for this paper is to improve the mathematical models for predicting heat explosion by using a specific case of the Fourier heat transfer system that focuses on thermoviscoelastic properties of materials. This is done by using a computational analysis to solve for an internal heat parameter that determines thermal failure at a critical value. This critical value is calculated under conditions either accounting for or negating the effect of heat dissipated by the material. This model is an improvement on existing models because it accounts for material specific properties and in doing so limits mathematical assumptions of the system. By limiting the assumptions in the conditions of the model, the model becomes more accurate and useful in regards to material design.展开更多
In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to...In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to reduce heat loss in buildings.Vacuum insulation panels(VIPs),a type of high-performance insulation material,have been increasingly utilised in the construction industry and have played an increa-singly important role as their performance and manufacturing processes continue to improve.This paper provides a review of the factors affecting the thermal conductivity of VIPs and presents a detailed overview of the research progress on core materials,barrier films,and getters.The current research status of VIPs is summarised,including their thermal conductivity,service life,and thermal bridging effects,as well as their applications in the field of architecture.This review aims to provide a comprehensive understanding for relevant practitioners on the factors influencing the thermal conductivity of VIPs,and based on which,measures can be taken to produce VIPs with lower thermal conductivity and longer service life.展开更多
The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature c...The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature conditions,measurement while drilling(MWD)instruments are highly likely to malfunction due to the inadequate temperature resistance of their electronic components.As a wellbore temperature control approach,the application of thermal insulated drill pipe(TIDP)has been proposed to manage the wellbore temperature in ultra-deep wells.This paper developed a temperature field model for ultra-deep wells by coupling the interactions of multiple factors on the wellbore temperature.For the first time,five distinct TIDP deployment methods were proposed,and their corresponding wellbo re temperature variation characte ristics were investigated,and the heat transfer laws of the ultra-deep wellbore-formation system were quantitatively elucidated.The results revealed that TIDP can effectively restrain the rapid rise in the temperature of the drilling fluid inside the drill string by reducing the heat flux of the drill string.Among the five deployment methods,the method of deploying TIDP from the bottomhole upwards exhibits the best performance.For a 12,000 m simulated well,when6000 m of TIDP are deployed from the bottomhole upwards,the BHT decreases by 52℃,while the outlet temperature increases by merely 1℃.This not only achieves the objective of wellbore temperature control but also keeps the temperature of the drilling fluid at the outlet of annulus at a relatively low level,thereby reducing the requirements for the heat exchange equipment on the ground.The novel findings of this study provide significant guidance for wellbore temperature control in ultra-deep and ultra-high-temperature wells.展开更多
Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably pl...Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably placed sensors to assess the state of the infrastructure represent a fundamental step,particularly for the railway sector,whose safe and continuous operation plays a strategic role in the well-being and development of nations.In this scenario,the benefits of a digital twin of a bonded insu-lated rail joint(IRJ)with the predictive capabilities of advanced classification algorithms based on artificial intelligence have been explored.The digital model provides an accurate mechanical response of the infrastructure as a pair of wheels passes over the joint.As bolt preload conditions vary,four structural health classes were identified for the joint.Two parameters,i.e.gap value and vertical displacement,which are strongly correlated with bolt preload,are used in different combinations to train and test five predictive classifiers.Their classification effectiveness was assessed using several performance indica-tors.Finally,we compared the IRJ condition predictions of two trained classifiers with the available data,confirming their high accuracy.The approach presented provides an interesting solution for future predictive tools in SHM especially in the case of complex systems such as railways where the vehicle-infrastructure interaction is complex and always time varying.展开更多
As a lightweight nanomaterial,Polyhedral Oligomeric Silsesquioxane(POSS)is widely applied to ablation resistance modification of Ethylene-Propylene-Dine Monomer(EPDM)insulation layer in aerospace propulsion thermal pr...As a lightweight nanomaterial,Polyhedral Oligomeric Silsesquioxane(POSS)is widely applied to ablation resistance modification of Ethylene-Propylene-Dine Monomer(EPDM)insulation layer in aerospace propulsion thermal protection system.However,various structures of POSS can form different crosslinked structures within the EPDM,which can affect the insulation layer properties.Various functionality POSS,Mono-Norbornene POSS(MN-POSS)and TriNorbornene POSS(TN-POSS),were designed and synthesized to obtain crosslinked-modified EPDMs with enhanced mechanical properties and ablation resistance simultaneously,and the relationship between POSS functionality,the mechanical properties,ablation resistance,heat-shielding and thermal decomposition of EPDM/Aramid Fiber(AF)composites were explored comprehensively.MN-POSS and TN-POSS increased the tensile strength of EPDM composites by 25.3%and 75.2%respectively,reduced the linear ablation rate by 37.7%and 33.7%respectively,and reduced the back temperatures by 3.9℃ and 3.3℃ respectively.Under conditions of equal cage structure(T8),the suspended crosslinked structure caused by MN-POSS exhibited better ablation resistance and heat-shielding performance as well as thermal decomposition,and the anchored crosslinked structure caused by TN-POSS exhibited better tensile strength.The structural transformation indicates that the POSS nanocages can be transformed into a ceramic structure in cruel environments to resist the erosion of heat flow and enhance the ablation resistance of insulation layer.展开更多
In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion s...In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion source.Through the finite element analysis method,the electrostatic analyses of insulators and grid plates were carried out,the material and structure parameters of insulators were determined.The maximum electric field around each insulator is about 4 kV/mm,and the maximum electric field between grids is about 14 kV/mm,which can meet the 120 keV withstand voltage holding.The insulation system for the positive ion source accelerator with 120 keV is designed,and the connection and basic parameters of insulators and support flanges are analyzed and determined.展开更多
Electron-hole interactions play a crucial role in determining the optoelectronic properties of materials,and in lowdimensional systems this is especially true due to the decrease of screening.In this review,we focus o...Electron-hole interactions play a crucial role in determining the optoelectronic properties of materials,and in lowdimensional systems this is especially true due to the decrease of screening.In this review,we focus on one unique quantum phase induced by the electron-hole interaction in two-dimensional systems,known as“exciton insulators”(EIs).Although this phase of matter has been studied for more than half a century,suitable platforms for its stable realization remain scarce.We provide an overview of the strategies to realize EIs in accessible materials and structures,along with a discussion on some unique properties of EIs stemming from the band structures of these materials.Additionally,signatures in experiments to distinguish EIs are discussed.展开更多
Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TB...Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.展开更多
The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges be...The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.展开更多
https://www.sciencedirect.com/journal/energy-and-buildings/vol/350/suppl/CV olume 350,1 January 2026[OA]( 1)Rooftop agrivoltaic powered onsite hydrogenp roduction for insulated gasochromic smart glazing and hydrogen v...https://www.sciencedirect.com/journal/energy-and-buildings/vol/350/suppl/CV olume 350,1 January 2026[OA]( 1)Rooftop agrivoltaic powered onsite hydrogenp roduction for insulated gasochromic smart glazing and hydrogen vehicles:A holistic approach to sustainabler esidential building by Shanza Neda Hussain,Aritra Ghosh,Article 116675 A bstract:The study focused on designing a sustainable buildingi nvolving rooftop agrivoltaics,advanced glazing technologies ando nsite hydrogen production for a residential property in Birmingham,UK where green hydrogen produced by harnessinge lectricity generated by agrivoltaics system on rooftop of the building is employed to change the transparency of vacuum gasochromic glazing and refuel hydrogen-powered fuel cell vehicle using storage hydrogen for a sustainable building approach.展开更多
Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always...Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.展开更多
Outlast Technologies GmbH has been awarded the WTiN Innovate Textile Award in the category Material Innovation for Aersulate®,its aerogel-infused insulation technology.The award honors outstanding achievements in...Outlast Technologies GmbH has been awarded the WTiN Innovate Textile Award in the category Material Innovation for Aersulate®,its aerogel-infused insulation technology.The award honors outstanding achievements in advanced material development and textile innovation.Aersulate® marks a significant advancement in thermal insulation.The technology integrates aerogel,whose highly porous structure efficiently traps air,delivering exceptional thermal performance at extremely low weight and minimal thickness.In AersulateR wadding,aerogel accounts for approximately 50%of the material volume,enabling superior insulation without bulk.展开更多
Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typical...Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typically evaluated by a dimensionless figure of merit (ZT = S2σT/(κe+ κl)), which depends on the delicate interplay among the electrical conductivity (σ), Seebeck coefficient (S), lattice thermal conductivity (κl), and electronic thermal conductivity (κe) [4].展开更多
When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–el...When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling.展开更多
Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectiv...Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectively.While these materials are affordable and display good thermal insulation,their unsustainable traits pertaining to an intensive manufacturing process and poor disposability are major concerns.Alternative insulation materials with enhanced sustainable characteristics are therefore being explored,and one type of material which has gained notable attention owing to its low carbon footprint and low thermal conductivity is natural fibre.Among the few review studies conducted on Natural Fibre Reinforced Composite(NFRC)insulation boards,the multitude of factors and underlying mechanisms affecting their thermal conductivity performance have been sparsely covered.This review study aimed to address this gap by providing a holistic overview of some of the key intrinsic and extrinsic factors affecting the thermal conductivity performance of NFRCs.Key intrinsic factors pertaining to the microstructural features and to the physico-mechanical traits of NFRCs,namely the fibre lumen size,α,and the fibre-matrix thermal conductivity ratio,β,respectively,were found to largely affect the Transverse Thermal Conductivity(TTC)in NFRC boards.Extrinsic factors,which were found to indirectly affect NFRCs’thermal conductivity,such as fibre pre-processing,composite manufacturing and environmental factors,were also covered.Some of the noteworthy NFRC featureswhich were found to affect their thermal conductivity are volume fraction of fibres,bulk density and porosity.The findings of this study highlight the need for additional research investigation to address the foregoing limitations observed in NFRC thermal insulation boards by considering appropriate natural fibres,composition and fabrication techniques.The fabrication of high-grade NFRC boards,which will display an optimum balance between enhanced thermal insulation and long-term durability performance,could further replace conventionally used thermal insulation boards in the modern building and construction industry.展开更多
Oligodendrocytes and their cell-intrinsic gene regulatory network:Oligodendrocytes(OLs)are the myelinating glial cells of the vertebrate central nervous system.They are responsible for insulating neuronal axons with a...Oligodendrocytes and their cell-intrinsic gene regulatory network:Oligodendrocytes(OLs)are the myelinating glial cells of the vertebrate central nervous system.They are responsible for insulating neuronal axons with a lipid-rich myelin sheath,which enables the saltatory conduction of action potentials.During development,oligodendrocyte progenitor cells(OPCs)emerge from neural stem cells in the ventricular zone.They then proliferate,increase their number,and migrate to their final destination where they encounter unmyelinated neuronal axons and differentiate in a stepwise fashion into myelinating oligodendrocytes(mOLs)under the influence of environmental stimuli.展开更多
In conventional higher-order topological insulators(HOTIs),the emergence of topological states can be explained by using the nonzero bulk polarization index.However,corner states emerge in HOTIs with incomplete bounda...In conventional higher-order topological insulators(HOTIs),the emergence of topological states can be explained by using the nonzero bulk polarization index.However,corner states emerge in HOTIs with incomplete boundary unit cells(i.e.,boundary defects)even though the bulk polarization is zero,which challenges the conventional understanding of HOTIs.Here,based on a Kekul´e-distorted honeycomb lattice with incomplete unit cells,we reveal that incomplete unit cells exhibit fractional charges through the analysis of Wannier centers by developing a compensation method and creating the concept of Wannier center domain(WCD)which is the smallest region that one Wannier center occupies.This method compensates for the missing parts of these boundary incomplete unit cells with additional WCDs to make them complete.The compensated WCDs automatically carry the corresponding charge,and this charge together with that of the incomplete unit cell constitutes the total charge of the complete unit cell after compensation.We conclude that the emergence of corner states is attributed to the filling anomaly,which is a fundamental mechanism.Our results refresh the understanding of HOTIs,especially those with structural discontinuities,and provide a novel design for topological states which have application value in producing optical functional devices.展开更多
A novel lateral insulated gate bipolar transistor on a silicon-on-insulator substrate SOI-LIGBT with a special low-doped P-well structure is proposed.The P-well structure is added to attach the P-body under the channe...A novel lateral insulated gate bipolar transistor on a silicon-on-insulator substrate SOI-LIGBT with a special low-doped P-well structure is proposed.The P-well structure is added to attach the P-body under the channel so as to reduce the linear anode current degradation without additional process.The influence of the length and depth of the P-well on the hot-carrier HC reliability of the SOI-LIGBT is studied.With the increase in the length of the P-well the perpendicular electric field peak and the impact ionization peak diminish resulting in the reduction of the hot-carrier degradation. In addition the impact ionization will be weakened with the increase in the depth of the P-well which also makes the hot-carrier degradation decrease.Considering the effect of the low-doped P-well and the process windows the length and depth of the P-well are both chosen as 2 μm.展开更多
Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper w...Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper wick （SCLS-SPC） is proposed to meet the requirements of higher device level heat fluxes and the harsh environments in some applications such as hybrid, fuel cell vehicles and aerospace. Fuzzy logic and proportional-integral-derivative （PID） policies are applied to adjust the electronic temperature within a safe working range. To evaluate the thermal control effect, a mathematical model of a 4-node thermal network and pump are established for predicting the dynamics of the SCLS-SPC. Moreover, the transient response of the 4 nodes and vapor mass flowrate under no control, PID and Fuzzy-PID are numerically investigated and discussed in detail.展开更多
基金Project(10YZ156) supported by Innovation Program of Shanghai Municipal Education Commission, China Project(sdl09009) supported by Training Program for Outstanding Youth Teacher of Shanghai Municipal Education Commission, China Project(Z2010-103) supported by Shanghai Education Development Foundation, China
文摘Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Based on the field study result, by using the simulation sol, ware, THERB, the effectiveness of the crawlspace warm air heating system has been examined. The effect of the factors, such as the wind amount circulating between crawlspace and indoor space, foundation insulation condition, and heat amount into the crawlspace, on the indoor thermal environment has been analyzed. Based on these analyses, the measured crawlspace heating system can make the average temperature of the living room above 20℃. These two houses have excellent thermal environment. According to the simulating result, heat amount input into crawlspace, which can make comfortable indoor thermal environment, for every month in heating period has been roughly concluded, and they are 600 W in December and March and 800 W in February and January, respectively.
文摘In the scope of material science, it is well understood that mechanical behavior of a material is temperature dependent. The converse is also true and for specific loading cases contributes to a unique thermal failure mechanism known as “heat explosion”. The goal for this paper is to improve the mathematical models for predicting heat explosion by using a specific case of the Fourier heat transfer system that focuses on thermoviscoelastic properties of materials. This is done by using a computational analysis to solve for an internal heat parameter that determines thermal failure at a critical value. This critical value is calculated under conditions either accounting for or negating the effect of heat dissipated by the material. This model is an improvement on existing models because it accounts for material specific properties and in doing so limits mathematical assumptions of the system. By limiting the assumptions in the conditions of the model, the model becomes more accurate and useful in regards to material design.
文摘In recent years,there has been a growing global demand for carbon neutrality and energy efficiency,which are expected to become long-term trends.In the field of architecture,an effective approach to achieve this is to reduce heat loss in buildings.Vacuum insulation panels(VIPs),a type of high-performance insulation material,have been increasingly utilised in the construction industry and have played an increa-singly important role as their performance and manufacturing processes continue to improve.This paper provides a review of the factors affecting the thermal conductivity of VIPs and presents a detailed overview of the research progress on core materials,barrier films,and getters.The current research status of VIPs is summarised,including their thermal conductivity,service life,and thermal bridging effects,as well as their applications in the field of architecture.This review aims to provide a comprehensive understanding for relevant practitioners on the factors influencing the thermal conductivity of VIPs,and based on which,measures can be taken to produce VIPs with lower thermal conductivity and longer service life.
基金supported by the National Natural Science Foundation of China(Grant No.U22B2072)Research Project of China Petroleum Science and Technology Innovation Fund(Grant No.2025DQ02-0144)。
文摘The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature conditions,measurement while drilling(MWD)instruments are highly likely to malfunction due to the inadequate temperature resistance of their electronic components.As a wellbore temperature control approach,the application of thermal insulated drill pipe(TIDP)has been proposed to manage the wellbore temperature in ultra-deep wells.This paper developed a temperature field model for ultra-deep wells by coupling the interactions of multiple factors on the wellbore temperature.For the first time,five distinct TIDP deployment methods were proposed,and their corresponding wellbo re temperature variation characte ristics were investigated,and the heat transfer laws of the ultra-deep wellbore-formation system were quantitatively elucidated.The results revealed that TIDP can effectively restrain the rapid rise in the temperature of the drilling fluid inside the drill string by reducing the heat flux of the drill string.Among the five deployment methods,the method of deploying TIDP from the bottomhole upwards exhibits the best performance.For a 12,000 m simulated well,when6000 m of TIDP are deployed from the bottomhole upwards,the BHT decreases by 52℃,while the outlet temperature increases by merely 1℃.This not only achieves the objective of wellbore temperature control but also keeps the temperature of the drilling fluid at the outlet of annulus at a relatively low level,thereby reducing the requirements for the heat exchange equipment on the ground.The novel findings of this study provide significant guidance for wellbore temperature control in ultra-deep and ultra-high-temperature wells.
基金the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.4-Call for tender No. 3138 of 16/12/2021 of Italian Ministry of University and Research funded by the European Union-Next Generation EU. Award Number: Project code CN00000023Concession Decree No. 1033 of 17/06/2022 adopted by the Italian Ministry of University and Research, CUP D93C22000400001, “Sustainable Mobility Center” (CNMS). Spoke 4-Rail Transportation
文摘Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably placed sensors to assess the state of the infrastructure represent a fundamental step,particularly for the railway sector,whose safe and continuous operation plays a strategic role in the well-being and development of nations.In this scenario,the benefits of a digital twin of a bonded insu-lated rail joint(IRJ)with the predictive capabilities of advanced classification algorithms based on artificial intelligence have been explored.The digital model provides an accurate mechanical response of the infrastructure as a pair of wheels passes over the joint.As bolt preload conditions vary,four structural health classes were identified for the joint.Two parameters,i.e.gap value and vertical displacement,which are strongly correlated with bolt preload,are used in different combinations to train and test five predictive classifiers.Their classification effectiveness was assessed using several performance indica-tors.Finally,we compared the IRJ condition predictions of two trained classifiers with the available data,confirming their high accuracy.The approach presented provides an interesting solution for future predictive tools in SHM especially in the case of complex systems such as railways where the vehicle-infrastructure interaction is complex and always time varying.
基金the support from the Xianyang Major Scientific and Technological Innovation Special Project—University and Research Institute“Three-Item Reform”Technology Transfer Project,China(No.D5140240003)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.CX2023093)。
文摘As a lightweight nanomaterial,Polyhedral Oligomeric Silsesquioxane(POSS)is widely applied to ablation resistance modification of Ethylene-Propylene-Dine Monomer(EPDM)insulation layer in aerospace propulsion thermal protection system.However,various structures of POSS can form different crosslinked structures within the EPDM,which can affect the insulation layer properties.Various functionality POSS,Mono-Norbornene POSS(MN-POSS)and TriNorbornene POSS(TN-POSS),were designed and synthesized to obtain crosslinked-modified EPDMs with enhanced mechanical properties and ablation resistance simultaneously,and the relationship between POSS functionality,the mechanical properties,ablation resistance,heat-shielding and thermal decomposition of EPDM/Aramid Fiber(AF)composites were explored comprehensively.MN-POSS and TN-POSS increased the tensile strength of EPDM composites by 25.3%and 75.2%respectively,reduced the linear ablation rate by 37.7%and 33.7%respectively,and reduced the back temperatures by 3.9℃ and 3.3℃ respectively.Under conditions of equal cage structure(T8),the suspended crosslinked structure caused by MN-POSS exhibited better ablation resistance and heat-shielding performance as well as thermal decomposition,and the anchored crosslinked structure caused by TN-POSS exhibited better tensile strength.The structural transformation indicates that the POSS nanocages can be transformed into a ceramic structure in cruel environments to resist the erosion of heat flow and enhance the ablation resistance of insulation layer.
基金supported by National Natural Science Foundation of China(No.11975261)。
文摘In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion source.Through the finite element analysis method,the electrostatic analyses of insulators and grid plates were carried out,the material and structure parameters of insulators were determined.The maximum electric field around each insulator is about 4 kV/mm,and the maximum electric field between grids is about 14 kV/mm,which can meet the 120 keV withstand voltage holding.The insulation system for the positive ion source accelerator with 120 keV is designed,and the connection and basic parameters of insulators and support flanges are analyzed and determined.
基金supported by the National Key Research&Development Program of China(Grant Nos.2022YFA1403500 and 2021YFA1400500)the National Science Foundation of China(Grant Nos.62321004,12234001,and 12474215)+1 种基金supported by New Cornerstone Science Foundationa fellowship and a CRF award from the Research Grants Council of the Hong Kong Special Administrative Region,China(Grant Nos.HKUST SRFS2324-6S01 and C7037-22GF)。
文摘Electron-hole interactions play a crucial role in determining the optoelectronic properties of materials,and in lowdimensional systems this is especially true due to the decrease of screening.In this review,we focus on one unique quantum phase induced by the electron-hole interaction in two-dimensional systems,known as“exciton insulators”(EIs).Although this phase of matter has been studied for more than half a century,suitable platforms for its stable realization remain scarce.We provide an overview of the strategies to realize EIs in accessible materials and structures,along with a discussion on some unique properties of EIs stemming from the band structures of these materials.Additionally,signatures in experiments to distinguish EIs are discussed.
基金Supported by Scientific and Technological Innovation of Shaanxi Provincial State-Owned Capital Operation Budget(2022-056)Institute's Self-Developed Technology Program(0801YK2317)+4 种基金Qin Chuangyuan Cites High-Level Innovation and Entrepreneurship Talent Program(QCYRCXM-2023-120)Qin Chuangyuan Industry Cluster Zone“Four Chains”Integration Program(2024CY-JJQ-46)National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos.XDB28000000 and XDB0460000)the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2021ZD0302600)the National Key Research and Development Program of China(Grant No.2024YFA1409002)。
文摘The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
文摘https://www.sciencedirect.com/journal/energy-and-buildings/vol/350/suppl/CV olume 350,1 January 2026[OA]( 1)Rooftop agrivoltaic powered onsite hydrogenp roduction for insulated gasochromic smart glazing and hydrogen vehicles:A holistic approach to sustainabler esidential building by Shanza Neda Hussain,Aritra Ghosh,Article 116675 A bstract:The study focused on designing a sustainable buildingi nvolving rooftop agrivoltaics,advanced glazing technologies ando nsite hydrogen production for a residential property in Birmingham,UK where green hydrogen produced by harnessinge lectricity generated by agrivoltaics system on rooftop of the building is employed to change the transparency of vacuum gasochromic glazing and refuel hydrogen-powered fuel cell vehicle using storage hydrogen for a sustainable building approach.
基金supported by Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001)the National Natural Science Foundation of China(No.52273053)the Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.21CGA41)。
文摘Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.
文摘Outlast Technologies GmbH has been awarded the WTiN Innovate Textile Award in the category Material Innovation for Aersulate®,its aerogel-infused insulation technology.The award honors outstanding achievements in advanced material development and textile innovation.Aersulate® marks a significant advancement in thermal insulation.The technology integrates aerogel,whose highly porous structure efficiently traps air,delivering exceptional thermal performance at extremely low weight and minimal thickness.In AersulateR wadding,aerogel accounts for approximately 50%of the material volume,enabling superior insulation without bulk.
基金supports from the Department of Education of Liaoning Province (LJ242510147006)
文摘Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typically evaluated by a dimensionless figure of merit (ZT = S2σT/(κe+ κl)), which depends on the delicate interplay among the electrical conductivity (σ), Seebeck coefficient (S), lattice thermal conductivity (κl), and electronic thermal conductivity (κe) [4].
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52225207 and 52350001)the Shanghai Pilot Program for Basic Research–Fudan University 21TQ1400100(Grant No.21TQ006)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)。
文摘When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling.
文摘Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectively.While these materials are affordable and display good thermal insulation,their unsustainable traits pertaining to an intensive manufacturing process and poor disposability are major concerns.Alternative insulation materials with enhanced sustainable characteristics are therefore being explored,and one type of material which has gained notable attention owing to its low carbon footprint and low thermal conductivity is natural fibre.Among the few review studies conducted on Natural Fibre Reinforced Composite(NFRC)insulation boards,the multitude of factors and underlying mechanisms affecting their thermal conductivity performance have been sparsely covered.This review study aimed to address this gap by providing a holistic overview of some of the key intrinsic and extrinsic factors affecting the thermal conductivity performance of NFRCs.Key intrinsic factors pertaining to the microstructural features and to the physico-mechanical traits of NFRCs,namely the fibre lumen size,α,and the fibre-matrix thermal conductivity ratio,β,respectively,were found to largely affect the Transverse Thermal Conductivity(TTC)in NFRC boards.Extrinsic factors,which were found to indirectly affect NFRCs’thermal conductivity,such as fibre pre-processing,composite manufacturing and environmental factors,were also covered.Some of the noteworthy NFRC featureswhich were found to affect their thermal conductivity are volume fraction of fibres,bulk density and porosity.The findings of this study highlight the need for additional research investigation to address the foregoing limitations observed in NFRC thermal insulation boards by considering appropriate natural fibres,composition and fabrication techniques.The fabrication of high-grade NFRC boards,which will display an optimum balance between enhanced thermal insulation and long-term durability performance,could further replace conventionally used thermal insulation boards in the modern building and construction industry.
基金supported by grants from the Deutsche Forschungsgemeinschaft(DFG)to MW.
文摘Oligodendrocytes and their cell-intrinsic gene regulatory network:Oligodendrocytes(OLs)are the myelinating glial cells of the vertebrate central nervous system.They are responsible for insulating neuronal axons with a lipid-rich myelin sheath,which enables the saltatory conduction of action potentials.During development,oligodendrocyte progenitor cells(OPCs)emerge from neural stem cells in the ventricular zone.They then proliferate,increase their number,and migrate to their final destination where they encounter unmyelinated neuronal axons and differentiate in a stepwise fashion into myelinating oligodendrocytes(mOLs)under the influence of environmental stimuli.
基金supported by the Natural Science Basic Research Program of Shaanxi Province (Grant Nos.2024JC-JCQN-06 and2025JC-QYCX-006)the National Natural Science Foundation of China (Grant No.12474337)Chinese Academy of Sciences Project (Grant Nos.E4BA270100,E4Z127010F,E4Z6270100,and E53327020D)。
文摘In conventional higher-order topological insulators(HOTIs),the emergence of topological states can be explained by using the nonzero bulk polarization index.However,corner states emerge in HOTIs with incomplete boundary unit cells(i.e.,boundary defects)even though the bulk polarization is zero,which challenges the conventional understanding of HOTIs.Here,based on a Kekul´e-distorted honeycomb lattice with incomplete unit cells,we reveal that incomplete unit cells exhibit fractional charges through the analysis of Wannier centers by developing a compensation method and creating the concept of Wannier center domain(WCD)which is the smallest region that one Wannier center occupies.This method compensates for the missing parts of these boundary incomplete unit cells with additional WCDs to make them complete.The compensated WCDs automatically carry the corresponding charge,and this charge together with that of the incomplete unit cell constitutes the total charge of the complete unit cell after compensation.We conclude that the emergence of corner states is attributed to the filling anomaly,which is a fundamental mechanism.Our results refresh the understanding of HOTIs,especially those with structural discontinuities,and provide a novel design for topological states which have application value in producing optical functional devices.
基金The National Natural Science Foundation of China(No.61204083)the Natural Science Foundation of Jiangsu Province(No.BK2011059)the Program for New Century Excellent Talents in University(No.NCET-10-0331)
文摘A novel lateral insulated gate bipolar transistor on a silicon-on-insulator substrate SOI-LIGBT with a special low-doped P-well structure is proposed.The P-well structure is added to attach the P-body under the channel so as to reduce the linear anode current degradation without additional process.The influence of the length and depth of the P-well on the hot-carrier HC reliability of the SOI-LIGBT is studied.With the increase in the length of the P-well the perpendicular electric field peak and the impact ionization peak diminish resulting in the reduction of the hot-carrier degradation. In addition the impact ionization will be weakened with the increase in the depth of the P-well which also makes the hot-carrier degradation decrease.Considering the effect of the low-doped P-well and the process windows the length and depth of the P-well are both chosen as 2 μm.
文摘Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper wick （SCLS-SPC） is proposed to meet the requirements of higher device level heat fluxes and the harsh environments in some applications such as hybrid, fuel cell vehicles and aerospace. Fuzzy logic and proportional-integral-derivative （PID） policies are applied to adjust the electronic temperature within a safe working range. To evaluate the thermal control effect, a mathematical model of a 4-node thermal network and pump are established for predicting the dynamics of the SCLS-SPC. Moreover, the transient response of the 4 nodes and vapor mass flowrate under no control, PID and Fuzzy-PID are numerically investigated and discussed in detail.
