Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-...Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.展开更多
A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical...A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optimal product of strength and elongation （PSE 〉 30,000 MPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.展开更多
Soft magnetic properties of Fe82Mo7B10Cu1 nanocrystalline alloy were studied as a function of cooling condition. The results show that higher permeability and relaxation frequency can be obtained by the two-step cooli...Soft magnetic properties of Fe82Mo7B10Cu1 nanocrystalline alloy were studied as a function of cooling condition. The results show that higher permeability and relaxation frequency can be obtained by the two-step cooling method, and the pinning field of the sample obtained by this method is smaller than that of the furnace-cooled and water-quenched samples. This phenomenon was interpreted in terms of internal stress and the magnetic ordering of the residual amorphous phase. The two-step cooling treatment is an effective way to improve the soft magnetic properties of Fe82Mo7B10Cu1 nanocrystalline alloy.展开更多
Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performan...Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.展开更多
This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,includin...This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.展开更多
Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency...Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.展开更多
This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooli...This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooling systems.Through a combination of numerical simulation and experimental validation,the technical advantages and mechanisms of immersion cooling are systematically explored.Simulation results indicate that under a 3C fast-charging condition(inlet temperature 20℃,flow rate 36 L/min),the immersion cooling structure 3demonstrates a triple enhancement in thermal performance compared to the cold plate structure 1:a 13.06%reduction in peak temperature,a 31.67%decrease in overall maximum temperature difference,and a 47.62%decrease in single-cell temperature deviation,while also reducing flow resistance by 33.61%.Furthermore,based on the immersion cooling model,a small battery module comprising seven cylindrical cells was designed for thermal runaway testing via nail penetration.The results show that the peak temperature of the triggered cell was limited to 437.6℃,with a controllable temperature rise gradient of only 3.35℃/s and a rapid cooling rate of 0.6℃/s.The maximum temperature rise of adjacent cells was just 64.8℃,effectively inhibiting thermal propagation.Post-test disassembly revealed that the non-triggered cells retained>99.2%of their original voltage and>99%structural integrity,confirming the module’s ability to achieve“localized failure with global stability.”展开更多
Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass rat...Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.展开更多
The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the rel...The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.展开更多
Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain su...Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.展开更多
Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films t...Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films to enhance their cooling performance.In practical applications,thermal contact between the radiative cooling film and the object significantly influences the ultimate cooling performance.However,achieving optimal thermal contact has received limited attention.In this study,we propose and experimentally demonstrate a high-power,flexible,and magnetically attachable and detachable radiative cooling film.This film consists of polymer metasurface structures on a flexible magnetic layer.The monolithic design allows for convenient attachment to and detachment from steel or iron surfaces,ensuring optimal thermal contact with minimal thermal resistance and uniform temperature distribution.Our magnetic radiative cooling film exhibits superior cooling performance compared to non-magnetic alternatives.It can reduce the temperature of stainless-steel plates under sunlight by 15.2℃,which is 3.6℃ more than that achieved by non-magnetic radiative cooling films.The radiative cooling power can reach 259W·m^(-2) at a working temperature of 70℃.Unlike other commonly used attachment methods,such as thermal grease or one-off tape,our approach allows for detachment and reusability of the cooling film according to practical needs.This method offers great simplicity,flexibility,and cost-effectiveness,making it promising for broad applications,particularly on non-horizontal irregular surfaces previously considered challenging.展开更多
This study develops an analytical model to evaluate the cooling performance of a porous terracotta tubular direct evaporative heat and mass exchanger. By combining energy and mass balance equations with heat and mass ...This study develops an analytical model to evaluate the cooling performance of a porous terracotta tubular direct evaporative heat and mass exchanger. By combining energy and mass balance equations with heat and mass transfer coefficients and air psychrometric correlations, the model provides insights into the impact of design and operational parameters on the exchanger cooling performance. Validated against an established numerical model, it accurately simulates cooling behavior with a Root Mean Square Deviation of 0.43 - 1.18˚C under varying inlet air conditions. The results show that tube geometry, including equivalent diameter, flatness ratio, and length significantly influences cooling outcomes. Smaller diameters enhance wet-bulb effectiveness but reduce cooling capacity, while increased flatness and length improve both. For example, extending the flatness ratio of a 15 mm diameter, 0.6 m long tube from 1 (circular) to 4 raises the exchange surface area from 0.028 to 0.037 m2, increasing wet-bulb effectiveness from 60% to 71%. Recommended diameters range from 5 mm for tubes under 0.5 m to 1 cm for tubes 0.5 to 1 m in length. Optimal air velocities depend on tube length: 1 m/s for tubes under 0.8 m, 1.5 m/s for lengths of 0.8 to 1.2 m, and up to 2 m/s for longer tubes. This model offers a practical alternative to complex numerical and CFD methods, with potential applications in cooling tower optimization for thermal and nuclear power plants and geothermal heat exchangers.展开更多
Double-wall effusion cooling coupled with thermal barrier coating(TBC)is an important way of thermal protection for gas turbine vanes and blades of next-generation aero-engine,and formation of discrete crater holes by...Double-wall effusion cooling coupled with thermal barrier coating(TBC)is an important way of thermal protection for gas turbine vanes and blades of next-generation aero-engine,and formation of discrete crater holes by TBC spraying is an approved design.To protect both metal and TBC synchronously,a recommended geometry of crater is obtained through a fully automatic multi-objective optimization combined with conjugate heat transfer simulation in this work.The length and width of crater(i.e.,L/D and W/D)were applied as design variables,and the area-averaged overall effectiveness of the metal and TBC surfaces(i.e.,Φ_(av) and τ_(av))were selected as objective functions.The optimization procedure consists of automated geometry and mesh generation,conjugate heat transfer simulation validated by experimental data and Kriging surrogated model.The results showed that the Φ_(av) and τ_(av) are successfully increased respectively by 9.1%and 6.0%through optimization.Appropriate enlargement of the width and length of the crater can significantly improve the film coverage effect,since that the beneficial anti-CRVP is enhanced and the harmful CRVP is weakened.展开更多
We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially...We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially uncoupled,their interaction via the microcavity field leads to an indirect exciton-mode–mechanical-mode coupling.The coherent feedback loop is applied by feeding back a fraction of the output field of the cavity through a controllable beam splitter to the cavity’s input mirror.It is shown that the cooling capability is enhanced by effectively suppressing the Stokes process through coupling with the QW.Furthermore,the effect of the anti-Stokes process is enhanced through the application of the coherent feedback loop.This particular system configuration enables cooling of the mechanical resonator even in the unresolved sideband regime(USR).This study has some important guiding significance in the field of quantum information processing.展开更多
1|Introduction Conventional cooling systems exhibit substantial electricity consumption and environmental detriments through contin-uous greenhouse gas emissions.Thermal management accounts for approximately 50%of glo...1|Introduction Conventional cooling systems exhibit substantial electricity consumption and environmental detriments through contin-uous greenhouse gas emissions.Thermal management accounts for approximately 50%of global energy expenditure[1,2],necessitating urgent development of sustainable cooling alter-natives.Radiative cooling emerges as a passive thermal regu-lation strategy,operating without external energy input via direct infrared emission from materials to the environment[3].展开更多
Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distrib...Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distribution of the cold atomic cloud generated by ILC are strongly influenced by the distribution of cooling light and the structural geometry of the cavity,making precise characterization and optimization of cold atom distribution essential for practical applications.In this paper,we present an innovative flat diffuse cavity design with the dimensions approximating a quasi-two-dimensional configuration,which generates a sheet-like isotropic laser field inside the cavity through diffuse reflections.We thoroughly characterized the system’s performance under different optical parameter settings.A two-dimensional(2D)movable detection system was employed to detect the quasi-two-dimensional distribution of cold atoms.These results demonstrate the ability of ILC to produce diverse morphological and density distributions of cold atoms,which we anticipate will be suitable for quantum sensing.展开更多
During the daytime,conventional radiative coolers disregard the directionality of thermal radiation,thereby overlooking the upward radiation from the ground.This upward radiation enhances the outward thermal radiation...During the daytime,conventional radiative coolers disregard the directionality of thermal radiation,thereby overlooking the upward radiation from the ground.This upward radiation enhances the outward thermal radiation,leading to a substantial reduction in the subambient daytime radiative cooling performance.Conversely,radiative coolers featuring angular asymmetry and spectral selectivity effectively resolve the problem of thermal radiation directionality,successfully evading the interference caused by the ground-generated thermal radiation.This cooler overcomes the limitations posed by the angle of incident light,making it suitable for subambient daytime radiative cooling of vertical surfaces.Furthermore,by adjusting the structure of the cooler,the angular range of thermal radiation can be modulated,enabling the application of radiative cooling technology for intelligent temperature regulation of various inclined surfaces encountered in daily life.This innovative work makes a significant contribution to the development of subambient smart thermal interaction systems and opens up new possibilities for the practical application of radiative cooling.展开更多
Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influ...Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influencing the diffusion and precipitation behavior of micro-alloying elements.This study investigated the effects of the cooling rate on the microstructure and corrosion behavior of micro-Ca and-Y alloyed cast AZ91 alloy(i.e.,AZXW9100).To achieve various cooling rates,the alloys were prepared using three methods:steel mold casting(SMC),copper step mold casting(CSMC),and high-pressure die casting(HPDC).The corrosion behavior was analyzed through weight loss measurements,electrochemical impedance spectroscopy,and corrosion morphology observations.The results showed that the key microstructural factors influencing corrosion resistance differed between short-and long-term corrosion.As the cooling rate increased,the short-term corrosion rate was lowered from 0.91 mm/y(SMC)to 0.38 mm/y(HPDC),which was attributed to the decrease in the total area fractions of the eutecticαandβphases acting as galvanic corrosion sources.The long-term corrosion rate was reduced from 17.20 mm/y(SMC)to 0.71 mm/y(HPDC),which was revealed to be due to the enhanced connectivity of theβphase acting as corrosion barriers.Meanwhile,the increase in the cooling rate led to a modification of the Zn molar ratio in theβphase,reducing the Volta potential of theβphase from 101.8 m V to 66.9 m V.This reduction in the Volta potential of the main galvanic source also contributed to improved corrosion resistance.The HPDC AZXW9100 alloy produced in this study exhibited the lowest corrosion rate compared to other alloys.These findings suggest that controlling the cooling rate is a promising strategy for enhancing the corrosion resistance of AZXW9100 alloys.展开更多
Radiative cooling is a sustainable cooling technology,which can show great application in energy saving buildings.Cooling coatings gained more and more interest due to their easy processability and low cost.However,de...Radiative cooling is a sustainable cooling technology,which can show great application in energy saving buildings.Cooling coatings gained more and more interest due to their easy processability and low cost.However,developing scalable,highly solar reflective,outdoor stable and various-substrate-adaptive cooling coatings is still a great challenge.Here,a refractive index mismatch strategy was proposed to develop an organic-inorganic hybrid photonic coating by using nanocellulose-induced self-assembly process in the solution process.By mixing Al2O3,Mica and MOF as well as dispersing with cellulose nanofiber,hierarchical nanostructured coating can be obtained.Due to large amount of air pores and multiple scattering interface formation,the resultant cooling coatings exhibited high and broad sunlight reflectance of 96%and high infrared emittance of 93%.Outdoor field test demonstrated organic-inorganic hybrid photonic coating(OHPC)can achieve a daytime subambient cooling of 8.5°C during direct sunlight in Nanjing.Meanwhile,it can be brushed on different kinds of substrate,such as wood,tile,plastic,ceramic,glass,etc.,highlighting its universality.Most importantly,OHPC exhibited surface hydrophobicity and ultraviolet(UV)resistance.Energy simulation indicated over 50%cooling energy can be saved if OHPC is coated on the roofs and walls of buildings in China.This work paves the way for developing scalable,environment-adaptive,and stable daytime cooling coatings for energy savings.展开更多
The Ediacaran-Cambrian Petermann Orogen is a dextral transpressional orogen exposed in central Australia,which facilitated the exhumation of a high-pressure core and the deformation of the Neoproterozoic-Palaeozoic Am...The Ediacaran-Cambrian Petermann Orogen is a dextral transpressional orogen exposed in central Australia,which facilitated the exhumation of a high-pressure core and the deformation of the Neoproterozoic-Palaeozoic Amadeus Basin.Several studies have investigated the metamorphic and deformational evolution of the Petermann Orogen;however,the spatiotemporal variation of the deformation and cooling history is yet to be fully understood.In situ muscovite and biotite Rb-Sr geochronology,in combination with Ti-in-quartz thermometry is applied to map the spatiotemporal deformation and cooling patterns of the northern part of the Petermann Orogen.Interpreted muscovite Rb-Sr growth ages obtained from samples in the Petermann Nappe Complex(PNC),range between c.598 Ma and 565 Ma,which correlate with the timing of deformation during the 600-520 Ma Petermann Orogeny.Interpreted muscovite and biotite cooling ages are younger in the east of the PNC(c.556-541 Ma)and broadly correlate with the regional pattern of crustal heat production,suggesting that the geothermal gradient had a significant control on the timing and duration of cooling.Biotite Rb-Sr cooling ages between c.555 Ma and 497 Ma for the orogenic core show no correlation with high heat production areas,however,differences in exhumed crustal levels across the Petermann Orogen are observed:high-P granulite facies rocks in the orogenic core vs middle-upper crustal rocks in the PNC,indicating that at least part of the spatiotemporal variation of cooling ages can be attributed to differential exhumation during the Petermann Orogeny.Hence,crustal heat production and differential exhumation were likely the main controlling factors on the duration and variation of cooling rates in the Petermann Orogen.展开更多
文摘Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.
基金This work was supported by National Key R＆D Program of China （Grant No. 2017YFB0304402） and the Shanghai Municipal Natural Science Foundation （Grant No. 17ZR1410400）.
文摘A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optimal product of strength and elongation （PSE 〉 30,000 MPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.
基金Project(50501008) supported by the National Natural Science Foundation of China
文摘Soft magnetic properties of Fe82Mo7B10Cu1 nanocrystalline alloy were studied as a function of cooling condition. The results show that higher permeability and relaxation frequency can be obtained by the two-step cooling method, and the pinning field of the sample obtained by this method is smaller than that of the furnace-cooled and water-quenched samples. This phenomenon was interpreted in terms of internal stress and the magnetic ordering of the residual amorphous phase. The two-step cooling treatment is an effective way to improve the soft magnetic properties of Fe82Mo7B10Cu1 nanocrystalline alloy.
基金supported by the National Natural Science Foundation of China(NSFC 52130601 and 52106276)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)+1 种基金the University of Science and Technology of China-Southwest University of Science and Technology Counterpart Cooperation and Development Joint Fund(24LHJJ09)the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.
文摘This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.
基金supported by the National Natural Science Foundation of China(Nos.52275299,52105313)R&D Program of Beijing Municipal Education Commission(No.KM202210005036)+1 种基金Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0701)National Defense Basic Research Projects of China(No.JCKY2022405C002).
文摘Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.
文摘This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooling systems.Through a combination of numerical simulation and experimental validation,the technical advantages and mechanisms of immersion cooling are systematically explored.Simulation results indicate that under a 3C fast-charging condition(inlet temperature 20℃,flow rate 36 L/min),the immersion cooling structure 3demonstrates a triple enhancement in thermal performance compared to the cold plate structure 1:a 13.06%reduction in peak temperature,a 31.67%decrease in overall maximum temperature difference,and a 47.62%decrease in single-cell temperature deviation,while also reducing flow resistance by 33.61%.Furthermore,based on the immersion cooling model,a small battery module comprising seven cylindrical cells was designed for thermal runaway testing via nail penetration.The results show that the peak temperature of the triggered cell was limited to 437.6℃,with a controllable temperature rise gradient of only 3.35℃/s and a rapid cooling rate of 0.6℃/s.The maximum temperature rise of adjacent cells was just 64.8℃,effectively inhibiting thermal propagation.Post-test disassembly revealed that the non-triggered cells retained>99.2%of their original voltage and>99%structural integrity,confirming the module’s ability to achieve“localized failure with global stability.”
文摘Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.
基金supported by the Education and Teaching Research Project of Universities in Fujian Province(FBJY20230167).
文摘The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.
基金financially supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant No.52303106)Research Grants Council of Hong Kong SAR(16200720)+3 种基金Environment and Conservation Fund of Hong Kong SAR(Project No.21/2022)Research Institute of Sports Science and Technology(Project No.P0043535)Research Institute of Advanced Manufacturing(Project No.P0046125)the start-up fund for new recruits of Poly U(Project No.P0038855 and P0038858)。
文摘Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.
基金supported by the Australia Research Council through the Discovery Project scheme(DP190103186 and DP220100603)the Industrial Transformation Training Centres scheme(IC180100005)+5 种基金the Future Fellowship scheme(FT210100806)the Future Fellowship scheme(FT220100559)the Discovery Early Career Researcher Award scheme(DE230100383)the Shenzhen Science and Technology Program(GJHZ20240218113407015)the Natural Science Foundation of Shandong Province(ZR2021ME162)the Key Research and Development Program of Shandong Province,China(2022SFGC0501).
文摘Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films to enhance their cooling performance.In practical applications,thermal contact between the radiative cooling film and the object significantly influences the ultimate cooling performance.However,achieving optimal thermal contact has received limited attention.In this study,we propose and experimentally demonstrate a high-power,flexible,and magnetically attachable and detachable radiative cooling film.This film consists of polymer metasurface structures on a flexible magnetic layer.The monolithic design allows for convenient attachment to and detachment from steel or iron surfaces,ensuring optimal thermal contact with minimal thermal resistance and uniform temperature distribution.Our magnetic radiative cooling film exhibits superior cooling performance compared to non-magnetic alternatives.It can reduce the temperature of stainless-steel plates under sunlight by 15.2℃,which is 3.6℃ more than that achieved by non-magnetic radiative cooling films.The radiative cooling power can reach 259W·m^(-2) at a working temperature of 70℃.Unlike other commonly used attachment methods,such as thermal grease or one-off tape,our approach allows for detachment and reusability of the cooling film according to practical needs.This method offers great simplicity,flexibility,and cost-effectiveness,making it promising for broad applications,particularly on non-horizontal irregular surfaces previously considered challenging.
文摘This study develops an analytical model to evaluate the cooling performance of a porous terracotta tubular direct evaporative heat and mass exchanger. By combining energy and mass balance equations with heat and mass transfer coefficients and air psychrometric correlations, the model provides insights into the impact of design and operational parameters on the exchanger cooling performance. Validated against an established numerical model, it accurately simulates cooling behavior with a Root Mean Square Deviation of 0.43 - 1.18˚C under varying inlet air conditions. The results show that tube geometry, including equivalent diameter, flatness ratio, and length significantly influences cooling outcomes. Smaller diameters enhance wet-bulb effectiveness but reduce cooling capacity, while increased flatness and length improve both. For example, extending the flatness ratio of a 15 mm diameter, 0.6 m long tube from 1 (circular) to 4 raises the exchange surface area from 0.028 to 0.037 m2, increasing wet-bulb effectiveness from 60% to 71%. Recommended diameters range from 5 mm for tubes under 0.5 m to 1 cm for tubes 0.5 to 1 m in length. Optimal air velocities depend on tube length: 1 m/s for tubes under 0.8 m, 1.5 m/s for lengths of 0.8 to 1.2 m, and up to 2 m/s for longer tubes. This model offers a practical alternative to complex numerical and CFD methods, with potential applications in cooling tower optimization for thermal and nuclear power plants and geothermal heat exchangers.
基金Anhui Provincial Natural Science Foundation of China(2108085ME176)the Natural Science Foundation of China(52276043)。
文摘Double-wall effusion cooling coupled with thermal barrier coating(TBC)is an important way of thermal protection for gas turbine vanes and blades of next-generation aero-engine,and formation of discrete crater holes by TBC spraying is an approved design.To protect both metal and TBC synchronously,a recommended geometry of crater is obtained through a fully automatic multi-objective optimization combined with conjugate heat transfer simulation in this work.The length and width of crater(i.e.,L/D and W/D)were applied as design variables,and the area-averaged overall effectiveness of the metal and TBC surfaces(i.e.,Φ_(av) and τ_(av))were selected as objective functions.The optimization procedure consists of automated geometry and mesh generation,conjugate heat transfer simulation validated by experimental data and Kriging surrogated model.The results showed that the Φ_(av) and τ_(av) are successfully increased respectively by 9.1%and 6.0%through optimization.Appropriate enlargement of the width and length of the crater can significantly improve the film coverage effect,since that the beneficial anti-CRVP is enhanced and the harmful CRVP is weakened.
基金supported by the National Natural Science Foundation of China(Grant Nos.62061028 and 62461035)the Key Project of Natural Science Foundation of Jiangxi Province(Grant No.20232ACB202003)+2 种基金the Finance Science and Technology Special“contract system”Project of Nanchang University Jiangxi Province(Grant No.ZBG20230418015)the Natural Science Foundation of Chongqing(Grant No.CSTB2024NSCQ-MSX0412)the Opening Project of Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology(Grant No.ammt2021A-4).
文摘We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially uncoupled,their interaction via the microcavity field leads to an indirect exciton-mode–mechanical-mode coupling.The coherent feedback loop is applied by feeding back a fraction of the output field of the cavity through a controllable beam splitter to the cavity’s input mirror.It is shown that the cooling capability is enhanced by effectively suppressing the Stokes process through coupling with the QW.Furthermore,the effect of the anti-Stokes process is enhanced through the application of the coherent feedback loop.This particular system configuration enables cooling of the mechanical resonator even in the unresolved sideband regime(USR).This study has some important guiding significance in the field of quantum information processing.
基金the financial support from the National Key R&D Program of China(No.2020YFA0711500)the National Natural Science Foundation of China(Nos.52473215 and 52273248).
文摘1|Introduction Conventional cooling systems exhibit substantial electricity consumption and environmental detriments through contin-uous greenhouse gas emissions.Thermal management accounts for approximately 50%of global energy expenditure[1,2],necessitating urgent development of sustainable cooling alter-natives.Radiative cooling emerges as a passive thermal regu-lation strategy,operating without external energy input via direct infrared emission from materials to the environment[3].
基金supported by the National Natural Science Foun-dation of China(Grant No.92165107)the China Postdoctoral Science Foundation(Grant No.2022M723270)the National Defense Basic Scientific Research Pogram of China。
文摘Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distribution of the cold atomic cloud generated by ILC are strongly influenced by the distribution of cooling light and the structural geometry of the cavity,making precise characterization and optimization of cold atom distribution essential for practical applications.In this paper,we present an innovative flat diffuse cavity design with the dimensions approximating a quasi-two-dimensional configuration,which generates a sheet-like isotropic laser field inside the cavity through diffuse reflections.We thoroughly characterized the system’s performance under different optical parameter settings.A two-dimensional(2D)movable detection system was employed to detect the quasi-two-dimensional distribution of cold atoms.These results demonstrate the ability of ILC to produce diverse morphological and density distributions of cold atoms,which we anticipate will be suitable for quantum sensing.
基金supported by the National Natural Science Foundation of China(52473270 and T2422028)the China Postdoctoral Science Foundation(2024M763485)+1 种基金the National Key R&D Program of China(2022YFA1203304)the Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(start-up grant E1552102).
文摘During the daytime,conventional radiative coolers disregard the directionality of thermal radiation,thereby overlooking the upward radiation from the ground.This upward radiation enhances the outward thermal radiation,leading to a substantial reduction in the subambient daytime radiative cooling performance.Conversely,radiative coolers featuring angular asymmetry and spectral selectivity effectively resolve the problem of thermal radiation directionality,successfully evading the interference caused by the ground-generated thermal radiation.This cooler overcomes the limitations posed by the angle of incident light,making it suitable for subambient daytime radiative cooling of vertical surfaces.Furthermore,by adjusting the structure of the cooler,the angular range of thermal radiation can be modulated,enabling the application of radiative cooling technology for intelligent temperature regulation of various inclined surfaces encountered in daily life.This innovative work makes a significant contribution to the development of subambient smart thermal interaction systems and opens up new possibilities for the practical application of radiative cooling.
基金supported by the Materials and Components Technology Development Program of the Ministry of Trade,Industry,and Energy(MOTIE,South Korea)(No.20024843)。
文摘Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influencing the diffusion and precipitation behavior of micro-alloying elements.This study investigated the effects of the cooling rate on the microstructure and corrosion behavior of micro-Ca and-Y alloyed cast AZ91 alloy(i.e.,AZXW9100).To achieve various cooling rates,the alloys were prepared using three methods:steel mold casting(SMC),copper step mold casting(CSMC),and high-pressure die casting(HPDC).The corrosion behavior was analyzed through weight loss measurements,electrochemical impedance spectroscopy,and corrosion morphology observations.The results showed that the key microstructural factors influencing corrosion resistance differed between short-and long-term corrosion.As the cooling rate increased,the short-term corrosion rate was lowered from 0.91 mm/y(SMC)to 0.38 mm/y(HPDC),which was attributed to the decrease in the total area fractions of the eutecticαandβphases acting as galvanic corrosion sources.The long-term corrosion rate was reduced from 17.20 mm/y(SMC)to 0.71 mm/y(HPDC),which was revealed to be due to the enhanced connectivity of theβphase acting as corrosion barriers.Meanwhile,the increase in the cooling rate led to a modification of the Zn molar ratio in theβphase,reducing the Volta potential of theβphase from 101.8 m V to 66.9 m V.This reduction in the Volta potential of the main galvanic source also contributed to improved corrosion resistance.The HPDC AZXW9100 alloy produced in this study exhibited the lowest corrosion rate compared to other alloys.These findings suggest that controlling the cooling rate is a promising strategy for enhancing the corrosion resistance of AZXW9100 alloys.
基金the Nanjing Forestry University,the Natural Science Foundation of Jiangsu Province(No.BK20230404)the Advanced Analysis and Testing Center of Nanjing Forestry University.
文摘Radiative cooling is a sustainable cooling technology,which can show great application in energy saving buildings.Cooling coatings gained more and more interest due to their easy processability and low cost.However,developing scalable,highly solar reflective,outdoor stable and various-substrate-adaptive cooling coatings is still a great challenge.Here,a refractive index mismatch strategy was proposed to develop an organic-inorganic hybrid photonic coating by using nanocellulose-induced self-assembly process in the solution process.By mixing Al2O3,Mica and MOF as well as dispersing with cellulose nanofiber,hierarchical nanostructured coating can be obtained.Due to large amount of air pores and multiple scattering interface formation,the resultant cooling coatings exhibited high and broad sunlight reflectance of 96%and high infrared emittance of 93%.Outdoor field test demonstrated organic-inorganic hybrid photonic coating(OHPC)can achieve a daytime subambient cooling of 8.5°C during direct sunlight in Nanjing.Meanwhile,it can be brushed on different kinds of substrate,such as wood,tile,plastic,ceramic,glass,etc.,highlighting its universality.Most importantly,OHPC exhibited surface hydrophobicity and ultraviolet(UV)resistance.Energy simulation indicated over 50%cooling energy can be saved if OHPC is coated on the roofs and walls of buildings in China.This work paves the way for developing scalable,environment-adaptive,and stable daytime cooling coatings for energy savings.
基金supported by the Mineral Exploration Cooperative Research Centre whose activities are funded by the Australian Government’s Cooperative Research Centre Program.This is MinEx CRC Document 2025/06.
文摘The Ediacaran-Cambrian Petermann Orogen is a dextral transpressional orogen exposed in central Australia,which facilitated the exhumation of a high-pressure core and the deformation of the Neoproterozoic-Palaeozoic Amadeus Basin.Several studies have investigated the metamorphic and deformational evolution of the Petermann Orogen;however,the spatiotemporal variation of the deformation and cooling history is yet to be fully understood.In situ muscovite and biotite Rb-Sr geochronology,in combination with Ti-in-quartz thermometry is applied to map the spatiotemporal deformation and cooling patterns of the northern part of the Petermann Orogen.Interpreted muscovite Rb-Sr growth ages obtained from samples in the Petermann Nappe Complex(PNC),range between c.598 Ma and 565 Ma,which correlate with the timing of deformation during the 600-520 Ma Petermann Orogeny.Interpreted muscovite and biotite cooling ages are younger in the east of the PNC(c.556-541 Ma)and broadly correlate with the regional pattern of crustal heat production,suggesting that the geothermal gradient had a significant control on the timing and duration of cooling.Biotite Rb-Sr cooling ages between c.555 Ma and 497 Ma for the orogenic core show no correlation with high heat production areas,however,differences in exhumed crustal levels across the Petermann Orogen are observed:high-P granulite facies rocks in the orogenic core vs middle-upper crustal rocks in the PNC,indicating that at least part of the spatiotemporal variation of cooling ages can be attributed to differential exhumation during the Petermann Orogeny.Hence,crustal heat production and differential exhumation were likely the main controlling factors on the duration and variation of cooling rates in the Petermann Orogen.
