Maintaining high piezoelectric response and piezoelectric temperature stability of lead-based piezoceramics is critical for applications under high-temperature environments.Unfortunately,the piezoelectric response of ...Maintaining high piezoelectric response and piezoelectric temperature stability of lead-based piezoceramics is critical for applications under high-temperature environments.Unfortunately,the piezoelectric response of lead-based piezoceramics shows strong temperature dependence.Herein,an innovative strategy was proposed to solve this problem.The method consisted of constructing“slush-like”polar states by introducing localized heterostructures in the tetragonal phase structure to lower the energy barriers.The presence of the tetragonal phase stabilized the domain structure,providing excellent temperature stability,while the localized heterostructures also flattened the free energy landscape and enhanced the piezo-electric response.The strategy was implemented by using 0.11Pb(In_(0.5)Nb_(0.5))O_(3)-0.89Pb(Hf_(0.47)Ti_(0.53))O_(3)(PIN-PHT)piezoceramics doped with heterovalent ion Nb^(5+)to form a“slush-like”polar state with strong in-teractions inside the ceramics.The piezoelectric response and relaxor behavior of the ceramics were then investigated using piezoelectric force microscopy to reveal the mapping relationship between the complex ferroelectric domain structure and both the piezoelectric response and temperature stability.At Nb5+doping amount of 0.8 mol%,the ceramics showed excellent comprehensive performances with d_(33)=764 pC/N,T_(c)=319.1℃,ε_(r)=3253.59,k_(p)=0.67,and tan δ=0.0122.At an external ambient temperature of 300℃,the d_(33) of PIN-PHT-0.8Nb^(5+) remained high at 734 pC/N,with piezoelectric performance retention of 96.1%,showing excellent temperature stability.Overall,a new path was proposed for developing Pb-based piezoceramics with both good piezoelectric response and high-temperature stability,promising to broaden the temperature range of high-temperature piezoceramics for various applications.展开更多
Precipitation strengthening is a critical strategy for developing high-performance Cu alloys that combine exceptional strength with high conductivity.However,this method often loses effectiveness at elevated temperatu...Precipitation strengthening is a critical strategy for developing high-performance Cu alloys that combine exceptional strength with high conductivity.However,this method often loses effectiveness at elevated temperatures due to the poor thermal stability of the precipitates,which tend to coarsen rapidly,leading to accelerated mechanical degradation.In this study,we introduce a CuCrZrY alloy that demonstrates remarkable structural and mechanical stability at high temperatures.Notably,after annealing at 550℃ for 500 h,only 18.8%of the grains were recrystallized.Through a combination of experimental investigations and first-principles calculations,we discovered that the strong solute-vacancy binding energy of Y in Cu significantly impedes bulk diffusion of solute,thereby inhibiting precipitate coarsening and recrystallization.The coarsening rate constant for the CuCrZrY alloy was found to be approximately half that of the CuCrZr alloy.During prolonged annealing,the formation of sub-grains via recovery enhances boundary diffusion,leading to a layered distribution of precipitates.The recrystallization model further elucidates the interplay between eutectic phases,precipitates,and the migration of recrystallization boundaries.Initially,eutectic phases contribute to the accumulation of geometrically necessary dislocations during rolling,which triggers recrystallization in the early stages of annealing.Additionally,the triple junctions of sub-grain and recrystallization boundaries facilitate precipitate coarsening,thereby reducing the pinning force.Consequently,the CuCrZrY alloy undergoes a unique recrystallization process characterized by discontinuous precipitate coarsening and a cycle of pinning-depinning-repinning of recrystallized grain boundaries.These insights provide valuable guidance for designing Cu alloys with stable microstructural and mechanical properties under prolonged high-temperature conditions.展开更多
Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanis...Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.展开更多
The mechanical properties of the sample and the stability of retained austenite were studied by designing two kinds of ultra-fine bainitic steel with different heat treatment methods austempering above and below Ms(ma...The mechanical properties of the sample and the stability of retained austenite were studied by designing two kinds of ultra-fine bainitic steel with different heat treatment methods austempering above and below Ms(martensite start tem-perature),which were subjected to tensile tests at 20 and 450℃,respectively.The results show that compared to room temperature(20℃)tensile properties,the uniform elongation of the sample at high temperature(450℃)significantly decreased.Specifically,the uniform elongation of the sample austempered above Ms decreased from 8.0%to 3.5%,and the sample austempered below Ms decreased from 10.9%to 3.1%.Additionally,the tensile strength of the sample austempered above Ms significantly decreased(from 1281 to 912 MPa),and the sample austempered below Ms slightly decreased(from 1010 to 974 MPa).This was due to the high carbon content(1.60 wt.%),high mechanical stability,low thermal stability for the retained austenite of the sample austempered below Ms.Besides,the retained austenite decomposed at high temper-atures,the carbon content and transformation driving force were significantly reduced,the transformation rate increased,and the phase transformation content reduced.展开更多
In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepare...In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepared.The effects of structural properties,textural properties,oxygen vacancies,Ce^(3+),surface adsorbed oxygen species,reduction properties and desorption properties of oxygen species on the activity were analyzed by various characterization methods.The results of the activity test show that the addition of manganese is beneficial to enhancement of the activity,while the addition of yttrium increases the amount of reactive oxygen species,but decreases the activity.After aging at 700℃,the activity of the CeMn catalyst decreases most sharply,while the catalytic activity of the CeY catalyst can be maintained to a certain extent.Interestingly,the addition of yttrium and manganese at the same time can stabilize the activity.The fundamental reason is that yttrium and manganese move to the surface of the solid solution after aging,which increases the reduction performance of the catalyst,thus contributing to the increase of activity.Although the activity of CeYMn catalyst decreases after aging at 800℃,it is still higher than that of other catalysts aged at 700℃.展开更多
High-temperature stability of organic field-effect transistors(OFETs)is critical to ensure its long-term reliable operation under various environmental conditions.The molecular packing of donor-acceptor(D-A)conjugated...High-temperature stability of organic field-effect transistors(OFETs)is critical to ensure its long-term reliable operation under various environmental conditions.The molecular packing of donor-acceptor(D-A)conjugated polymers is closely related to the electrical performance stability in OFETs.Herein,we choose poly[[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)]as a modal system to reveal the relationship between the molecular stacking and electrical stability in high-temperature environment.The results demonstrate that the films with D-A moieties in alternate stacking have better electrical thermal stability compared to normal donor-donor(D-D)stacking.The D-A stacking configuration alternates donor and acceptor units along the out-of-plane direction,while the D-D stacking involves D-D and A-A stacking separately.The structural transition from D-D to D-A is captured at a treated temperature range of 225±250°C.Owing to the tighter packing arrangement along theπ-πand lamellar directions,the electron mobility of the D-A stacked films reaches up to 0.23 cm^(2)/V·s,a 50%increase as compared to the D-D stacking films.Furthermore,the D-A stacked films indicate superior electrical performance stability with mobility retaining 100%at 250°C during high-temperature cycling tests.This result highlights that the manipulation of conjugated polymer closely stacked structures can significantly enhance the thermal stability and durability of semiconductor devices.展开更多
Porous SiBCN ceramics exhibit great potential in high-tech structural and functional applications. However, nucleation-crystallization and carbothermal decomposition limit their use in high-temperature environments. H...Porous SiBCN ceramics exhibit great potential in high-tech structural and functional applications. However, nucleation-crystallization and carbothermal decomposition limit their use in high-temperature environments. Herein, high-entropy carbide (HEC) (Ti_(0.25)Zr_(0.25)Hf_(0.25)Ta_(0.25))C-modified porous SiBCN ceramics (HEC/SiBCN) were successfully fabricated from a multi-metal (Ti,Zr,Hf,Ta) precursor containing polyborosilazane via solvothermal methods, freeze-drying, and pyrolysis. The porous HEC/SiBCN ceramic possesses tailorable porosity (63.5%–79.1%), low thermal conductivity (0.054–0.089 W/(m·K)), and good mechanical strength. The HEC phase is in situ formed by carbothermal reduction and solid solution reaction of the multicomponent precursor with highly active free carbon in the SiBCN matrix during the pyrolysis, which endows the porous HEC/SiBCN ceramics with outstanding thermal stability up to 1800℃. The in situ formation of the HEC phase provides novel insight and a promising strategy for enhancing the overall performance of porous SiBCN ceramics, expanding their application in high-temperature environments.展开更多
The thermal stability of lithium-ion battery separators is a critical determinant of battery safety and performance,especially in the context of rapidly expanding applications in electric vehicles and energy storage s...The thermal stability of lithium-ion battery separators is a critical determinant of battery safety and performance,especially in the context of rapidly expanding applications in electric vehicles and energy storage systems.While traditional polyolefin separators(PP/PE)dominate the market due to their cost-effectiveness and mechanical robustness,their inherent poor thermal stability poses significant safety risks under high-temperature conditions.This review provides a comprehensive analysis of recent advancements in enhancing separator thermal stability through coating materials(metal,ceramic,inorganic)and novel high-temperature-resistant polymers(e.g.,PVDF copolymers,PI,PAN).Notably,we critically evaluate the trade-offs between thermal resilience and electrochemical performance,such as the unintended increase in electronic conductivity from metal coatings(e.g.,Cu,MOFs)and reduced electrolyte wettability in ceramic coatings(e.g.,Al_(2)O_(3)).Innovations in hybrid coatings(e.g.,BN/PAN composites,gradient-structured MOFs)and scalable manufacturing techniques(e.g.,roll-to-roll electrospinning)are highlighted as promising strategies to balance these competing demands.Furthermore,a comparative analysis of next-generation high-temperature-resistant separators underscores their ionic conductivity,mechanical strength,and scalability,offering actionable insights for material selection.The review concludes with forward-looking perspectives on integrating machine learning for material discovery,optimizing interfacial adhesion in ceramic coatings,and advancing semi-/all-solid-state batteries to address both thermal and electrochemical challenges.This work aims to bridge the gap between laboratory innovations and industrial applications,fostering safer and more efficient lithium battery technologies.展开更多
BaTiO_(3) (BT)-based piezoceramics with large temperature-stable strains and low hysteresis are urgently needed for high-precision actuators because of increasing environmental problems. Here, tetragonal [001]c-textur...BaTiO_(3) (BT)-based piezoceramics with large temperature-stable strains and low hysteresis are urgently needed for high-precision actuators because of increasing environmental problems. Here, tetragonal [001]c-textured (Ba_(0.98)Ca_(0.02))(Ti_(0.96)Sn_(0.04))O_(3) (BCTS) ceramics with a texture degree (F_(001)) of ~98% were obtained via the templated grain growth (TGG) method. A large maximum unipolar strain (S_(max)) of ~0.24% with a low strain hysteresis (Hs) of ~3.8% and an optimized piezoelectric strain coefficient (d_(33)^(*)) of ~1124 pm·V^(−1) are simultaneously achieved in the textured BCTS ceramics. Moreover, the variation in the strain response is less than 20% from room temperature (RT) to 100℃ for the textured ceramics. The underlying mechanism for the optimized strain performance could be attributed to the synergetic effect of the polarization extension and a fine domain structure. This work provides new insight for achieving a balance of multiple strain properties (large strain, low hysteresis, and high-temperature stability) in BT-based ceramics, showing the widespread application prospects of lead-free ceramics in high-precision actuators.展开更多
Sc was doped into Gd_(2)Zr_(2)O_(7) for expanding the potential for thermal barrier coating (TBC) applications. The solid solution mechanism of Sc in the Gd_(2)Zr_(2)O_(7) lattice, and the mechanical and thermophysica...Sc was doped into Gd_(2)Zr_(2)O_(7) for expanding the potential for thermal barrier coating (TBC) applications. The solid solution mechanism of Sc in the Gd_(2)Zr_(2)O_(7) lattice, and the mechanical and thermophysical properties of the doped Gd_(2)Zr_(2)O_(7) were systematically studied by the first-principles method, based on which the Sc doping content was optimized. Additionally, Sc-doped Gd_(2)Zr_(2)O_(7) TBCs with the optimized composition were prepared by air plasma spraying using YSZ as a bottom ceramic coating (Gd-Sc/YSZ TBCs), and their sintering behavior and thermal cycling performance were examined. Results revealed that at low Sc doping levels, Sc has a large tendency to occupy the lattice interstitial sites, and when the doping content is above 11.11 at%, Sc substituting for Gd in the lattice becomes dominant. Among the doped Gd_(2)Zr_(2)O_(7), the composition with 16.67 at% Sc content has the lowest Pugh’s indicator (G/B) and the highest Poisson ratio (σ) indicative of the highest toughness, and the decreasing trends of Debye temperature and thermal conductivity slow down at this composition. By considering the mechanical and thermophysical properties comprehensively, the Sc doping content was optimized to be 16.67 at%. The fabricated Gd-Sc coatings remain phase and structural stability after sintering at 1400 ℃ for 100 h. Gd-Sc/YSZ TBCs exhibit excellent thermal shock resistance, which is related to the good thermal match between Gd-Sc and YSZ coatings, and the buffering effect of the YSZ coating during thermal cycling. These results revealed that Sc-doped Gd_(2)Zr_(2)O_(7) has a high potential for TBC applications, especially for the composition with 16.67 at% Sc content.展开更多
The use of lignin,which is a by-product of the pulp and paper industry,in the development of asphalt binders would contribute to waste reduction,providing environmental,economic,and social benefits.In this study,sampl...The use of lignin,which is a by-product of the pulp and paper industry,in the development of asphalt binders would contribute to waste reduction,providing environmental,economic,and social benefits.In this study,samples of lignin-modified asphalt binder samples with different content of lignin(3%,6%,9%,12%,and 15%)and unmodified asphalt(control)were tested using Fourier transform infrared spectroscopy(FTIR),dynamic shear rheometer(DSR),and thermogravimetry.The mechanism and effectiveness of lignin in improving the thermal stability of asphalt at high temperatures were analyzed.The FTIR analysis shows that no new characteristic absorption peak is seen in the infrared spectral of the lignin-modified asphalt binder samples,and some bands characteristic of lignin-related peaks gradually increased with the increase of lignin content.This suggests that the modification of lignin-modified asphalt binder samples was due to physical blending rather than chemical modification.The increase of lignin content in the lignin-modified asphalt samples increases the complex shear modulus G*of the samples and decreases the phase angles of the samples.Similarly,the anti-rutting performance(G*/sinδ)of the samples improves with the increase in lignin content,but this is not significant after any addition of lignin that exceeds 12%of asphalt mass.Thermal characterizations show that the thermal decomposition rate of lignin is lower,and its residual amount is higher compared to that of asphalt,which is a major reason for the improved stability of lignin-modified asphalt binders at high temperatures.The effect of lignin on the thermal stability of asphalt is dependent on both lignin content and temperature.It has a positive effect on the thermal stability of asphalt at high temperatures within the range of asphalt service temperature(25℃–200℃).Additionally,from the pyrolysis viewpoint,it was explained that excessive lignin addition is not beneficial to the thermal stability of asphalt at high temperatures,which is consistent with the DSR test result conducted high temperatures.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
We investigate a class of non-integrable two-particle Calogero-Moser systems modulated by a power-law external potential.The local well-posedness of the Cauchy problem is established under the strict initial separatio...We investigate a class of non-integrable two-particle Calogero-Moser systems modulated by a power-law external potential.The local well-posedness of the Cauchy problem is established under the strict initial separation condition for the particles.For suitably prepared initial configurations,local solutions can be extended globally via energy conservation;conversely,negative energy conditions induce(in)finite-time blowup.The linear(in)stability of stationary solutions is analyzed,with their energy serving as a threshold.Numerical investigations employ a fourth-order Runge-Kutta scheme with adaptive step-size control.Simulations demonstrate that the trajectories either converge to steady states or exhibit blowup,depending on the power exponent α and initial conditions.Increasingαaccelerates the convergence rate and dampens oscillatory dynamics,promoting a transition from periodic behavior to static equilibrium.展开更多
Quantitative real-time PCR(qPCR)is widely used for gene expression analysis,but its accuracy critically depends on stable internal reference genes for normalization.In marine invertebrates,especially non-model taxa su...Quantitative real-time PCR(qPCR)is widely used for gene expression analysis,but its accuracy critically depends on stable internal reference genes for normalization.In marine invertebrates,especially non-model taxa such as cephalopods,systematic evaluation of reference genes is limited,leading to potential bias.The cuttlefish Sepiella japonica is ecologically and economically important in China,yet previous molecular studies have often relied on single unvalidated reference genes,which may compromise data reliability.This study aimed to systematically evaluate the stability of five commonly used reference genes(18S,ef-1α,ef-1γ,gapdh,andβ-actin)across multiple tissues and sexes of S.japonica,and to identify the most suitable reference genes and optimal number for qPCR normalization.Fifteen to sixteen tissue types were collected from ten healthy adults(five males and five females).Total RNA was extracted,reverse-transcribed,and analyzed by qPCR.Gene stability was assessed using four algorithms(geNorm,NormFinder,BestKeeper,andΔCt)integrated with RefFinder,and the optimal gene number was determined using geNorm pairwise variation(V_(n/n+1)<0.15).Four transcriptome-derived genes(creld2,cd109,acy1,and miox)were used for validation.The C_(t)values of the five genes ranged from 15.47 to 20.83.β-actin and gapdh showed pronounced variability in expression stability among tissues and sexes,indicating their limited suitability for normalization.18S exhibited the highest expression(mean C_(t):15.47-16.29)and lowest variability but displayed sex-biased expression,whereas ef-1αand ef-1γremained consistently stable across most tissues in both sexes,with ef-1αbeing the most robust and showing no sex-related bias.Although specific rankings varied among tissues and sexes,the comprehensive results indicated that ef-1αand ef-1γpossessed the highest overall stability,followed by 18S,whileβ-actin and gapdh were the least stable.The final comprehensive rankings were ef-1γ>ef-1α>18S>gapdh>β-actin(male)and ef-1α>ef-1γ>18S>gapdh>β-actin(female).geNorm analysis(V2/3<0.15)indicated that two genes,mainly ef-1αand ef-1γ,were generally sufficient for reliable normalization in most tissues.Validation confirmed that normalization using the stable ef-1αand ef-1γaccurately reflected the expression differences among tissues,whereasβ-actin and gapdh can bias or confound statistical analyses.ef-1αand ef-1γare identified as the most reliable reference gene combination for qPCR analysis in S.japonica,while 18S can serve as an auxiliary gene for within-sex comparisons.The use ofβ-actin or gapdh alone is not recommended.This study establishes a systematic framework for selecting reliable reference genes in S.japonica,thereby facilitating robust qPCR normalization and providing a foundation for future gene expression research in S.japonica and other cephalopods.展开更多
The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical pr...The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved cerami...In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.展开更多
High-temperature industries,as the primary consumers of energy,are greatly concerned with energy savings.Designing refractory linings with low thermal conductivity to reduce heat dissipation through high-temperature f...High-temperature industries,as the primary consumers of energy,are greatly concerned with energy savings.Designing refractory linings with low thermal conductivity to reduce heat dissipation through high-temperature furnace linings is a critical concern.In this study,a series of novel entropy-stabilized spinel materials are reported,and their potential applications in high-temperature industries are investigated.XRD and TEM results indicate that all materials possess a cubic spinel crystal structure with the■space group.Furthermore,these materials exhibit good phase stability at high temperatures.All entropy-stabilized spinel aggregates demonstrated high refractoriness(>1800℃)and a high load softening temperature(>1700℃).The impact of configurational entropy on the properties of entropy-stabilized spinel materials was also studied.As configurational entropy increased,the thermal conductivity of the entropy-stabilized spinel decreased,while slag corrosion resistance deteriorated.For the entropy-stabilized spinel with a configurational entropy value of 1.126R,it showed good high-temperature stability,reliable resistance to slag attack,and a low thermal conductivity of 2.776 W·m^(-1)·K^(-1)at 1000℃.展开更多
Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional...Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional assumption that the fill material exhibits a significantly lower stiffness than the host rocks.Significantly,a recent pioneering work revealed the time-dependent ground stability around a backfilled stope with vertical walls through numerical modeling.In practice,underground stopes typically exhibit a higher or lower degree of inclination.This alters the stress state in peripheral rocks and may induce severe instability and dilution,particularly in stope-hanging walls.Hence,it is imperative to analyze the time-dependent ground stability of inclined backfilled stopes for backfill structure design.Therefore,comprehensive numerical simulations were performed using FLAC3D to address this knowledge deficiency by incorporating a coupled analysis of the backfill consolidation behavior and long-term creep deformation in surrounding rocks.The ground stability was evaluated based on the confinement effectiveness,strength-stress ratio,stress path relative to the yield surface,and time-dependent stress redistribution in the rocks.A parametric study revealed that the inclination angle of the backfilled stope reduced the confinement effectiveness in the host rocks when the wall creep was minor.This exacerbated the rock mass sloughing potential.However,a backfilled stope with a shallower dip angle achieved superior ground stability enhancement when the creep deformation was substantial,by applying a more significant compression on the backfill and effectively mobilizing its passive support performance during consolidation.Additional simulations were conducted to analyze the effects of stope height and width,mine depth,mechanical properties of rocks,backfill compressibility,and filling gap on the time-dependent stress redistribution and stability around the inclined backfilled stope.展开更多
AIM:To investigate the effects of binocular fusional C-optotypes(positive/negative)and 2D planar C-optotypes on the amplitude and stability of transient accommodation(TAC)in adults,and to provide a basis for non-conta...AIM:To investigate the effects of binocular fusional C-optotypes(positive/negative)and 2D planar C-optotypes on the amplitude and stability of transient accommodation(TAC)in adults,and to provide a basis for non-contact myopia intervention.METHODS:This was a self-controlled study.Using redblue 3D technology,four experimental stages were set up:Test A[fixating on the 1 m negative fusional C-optotypes,8△base-in(BI)],Test B(fixating on the 5 m planar C-optotypes),Test C(fixating on the 1 m planar C-optotypes),and Test D[fixating on the 1 m positive fusional C-optotypes,20△base-out(BO)].A WAM-5500 open-field autorefractor was used to measure TAC and accommodative microfluctuations[evaluated via interquartile range(IQR)and median-based coefficient of variation(CVmed)].Additionally,the convergence accommodation to convergence(CA/C)ratio was calculated,and a visual fatigue questionnaire was administered to assess participants’subjective visual comfort.RESULTS:A total of 21 subjects(7 males,14 females;aged 23-41y)with normal binocular visual function were enrolled.The results showed that the TAC increased gradually across the four stages,and these values were Test A(-0.35±0.26 D)<Test B(-0.46±0.24 D)<Test C(-0.77±0.32 D)<Test D(-1.38±0.31 D).There were significant overall differences(F=56.136,P<0.001).Compared with Test C,Test A reduced TAC by 0.42 D(P<0.05),while Test D increased it by 0.61 D(P<0.001).There was no significant intergroup difference in accommodative fluctuation amplitude(all P>0.05),but the fluctuation stability of Test D showed a significant difference between the first 20s and the second 20s(P=0.017).The CA/C ratio was significantly higher in Test D(0.05±0.02 D/△)than in Test A(0.03±0.02 D/△,P=0.007),indicating stronger accommodation-convergence linkage during positive fusional fixation.The visual fatigue scores of all stages were low(median 0-1),with Test D slightly higher than Test B and Test C(P<0.05).No linear correlation was found between TAC and age(all r<0.1,P>0.05).CONCLUSION:Negative fusional C-optotypes induce ciliary muscle relaxation to reduce TAC,while positive fusional C-optotypes enhance accommodation-convergence coordination to increase TAC.The red-blue 3D-based noncontact training mode exhibits good safety(median visual fatigue scores:0-1 across all tests)and provides a novel dual-directional(relaxation-activation)strategy for myopia prevention and control.展开更多
基金support of the National Ceramic Industry Design Institute of China(No.NI-CID2022Z02)the Instrumental Analysis Center of Xidian University for providing test equipment,the Shaanxi Key Laboratory of High-Orbits-Electron Materials and Protection Technology for Aerospace,the Aeronautical Science Foundation of China(No.2022Z033081001)+1 种基金the Xidian University Specially Funded Project for Interdisciplinary Exploration(No.TZJH2024055)the financial supports of the Key Research and Development Program of Shaanxi(No.2022GY-184).
文摘Maintaining high piezoelectric response and piezoelectric temperature stability of lead-based piezoceramics is critical for applications under high-temperature environments.Unfortunately,the piezoelectric response of lead-based piezoceramics shows strong temperature dependence.Herein,an innovative strategy was proposed to solve this problem.The method consisted of constructing“slush-like”polar states by introducing localized heterostructures in the tetragonal phase structure to lower the energy barriers.The presence of the tetragonal phase stabilized the domain structure,providing excellent temperature stability,while the localized heterostructures also flattened the free energy landscape and enhanced the piezo-electric response.The strategy was implemented by using 0.11Pb(In_(0.5)Nb_(0.5))O_(3)-0.89Pb(Hf_(0.47)Ti_(0.53))O_(3)(PIN-PHT)piezoceramics doped with heterovalent ion Nb^(5+)to form a“slush-like”polar state with strong in-teractions inside the ceramics.The piezoelectric response and relaxor behavior of the ceramics were then investigated using piezoelectric force microscopy to reveal the mapping relationship between the complex ferroelectric domain structure and both the piezoelectric response and temperature stability.At Nb5+doping amount of 0.8 mol%,the ceramics showed excellent comprehensive performances with d_(33)=764 pC/N,T_(c)=319.1℃,ε_(r)=3253.59,k_(p)=0.67,and tan δ=0.0122.At an external ambient temperature of 300℃,the d_(33) of PIN-PHT-0.8Nb^(5+) remained high at 734 pC/N,with piezoelectric performance retention of 96.1%,showing excellent temperature stability.Overall,a new path was proposed for developing Pb-based piezoceramics with both good piezoelectric response and high-temperature stability,promising to broaden the temperature range of high-temperature piezoceramics for various applications.
基金supported by the National Natural Science Foundation of China(No.U21B2066).
文摘Precipitation strengthening is a critical strategy for developing high-performance Cu alloys that combine exceptional strength with high conductivity.However,this method often loses effectiveness at elevated temperatures due to the poor thermal stability of the precipitates,which tend to coarsen rapidly,leading to accelerated mechanical degradation.In this study,we introduce a CuCrZrY alloy that demonstrates remarkable structural and mechanical stability at high temperatures.Notably,after annealing at 550℃ for 500 h,only 18.8%of the grains were recrystallized.Through a combination of experimental investigations and first-principles calculations,we discovered that the strong solute-vacancy binding energy of Y in Cu significantly impedes bulk diffusion of solute,thereby inhibiting precipitate coarsening and recrystallization.The coarsening rate constant for the CuCrZrY alloy was found to be approximately half that of the CuCrZr alloy.During prolonged annealing,the formation of sub-grains via recovery enhances boundary diffusion,leading to a layered distribution of precipitates.The recrystallization model further elucidates the interplay between eutectic phases,precipitates,and the migration of recrystallization boundaries.Initially,eutectic phases contribute to the accumulation of geometrically necessary dislocations during rolling,which triggers recrystallization in the early stages of annealing.Additionally,the triple junctions of sub-grain and recrystallization boundaries facilitate precipitate coarsening,thereby reducing the pinning force.Consequently,the CuCrZrY alloy undergoes a unique recrystallization process characterized by discontinuous precipitate coarsening and a cycle of pinning-depinning-repinning of recrystallized grain boundaries.These insights provide valuable guidance for designing Cu alloys with stable microstructural and mechanical properties under prolonged high-temperature conditions.
基金Sponsored by the National Natural Science Foundation of China (50801005)
文摘Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(52071238)Leading Innovation and Entrepreneurship Team in Zhejiang Province(2021R01020)+2 种基金the Key Research and Development Program of Hubei Province(2021BAA057)Science and Technology Program of Guangxi Province(AA22068080)the 111 Project.
文摘The mechanical properties of the sample and the stability of retained austenite were studied by designing two kinds of ultra-fine bainitic steel with different heat treatment methods austempering above and below Ms(martensite start tem-perature),which were subjected to tensile tests at 20 and 450℃,respectively.The results show that compared to room temperature(20℃)tensile properties,the uniform elongation of the sample at high temperature(450℃)significantly decreased.Specifically,the uniform elongation of the sample austempered above Ms decreased from 8.0%to 3.5%,and the sample austempered below Ms decreased from 10.9%to 3.1%.Additionally,the tensile strength of the sample austempered above Ms significantly decreased(from 1281 to 912 MPa),and the sample austempered below Ms slightly decreased(from 1010 to 974 MPa).This was due to the high carbon content(1.60 wt.%),high mechanical stability,low thermal stability for the retained austenite of the sample austempered below Ms.Besides,the retained austenite decomposed at high temper-atures,the carbon content and transformation driving force were significantly reduced,the transformation rate increased,and the phase transformation content reduced.
基金Project supported by the National Natural Science Foundation of China(21962021)the Yunnan Fundamental Research Projects(202001AU070121)+1 种基金the National Natural Science Foundation of China(51908091)the Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities'Association(202101BA070001-084)。
文摘In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepared.The effects of structural properties,textural properties,oxygen vacancies,Ce^(3+),surface adsorbed oxygen species,reduction properties and desorption properties of oxygen species on the activity were analyzed by various characterization methods.The results of the activity test show that the addition of manganese is beneficial to enhancement of the activity,while the addition of yttrium increases the amount of reactive oxygen species,but decreases the activity.After aging at 700℃,the activity of the CeMn catalyst decreases most sharply,while the catalytic activity of the CeY catalyst can be maintained to a certain extent.Interestingly,the addition of yttrium and manganese at the same time can stabilize the activity.The fundamental reason is that yttrium and manganese move to the surface of the solid solution after aging,which increases the reduction performance of the catalyst,thus contributing to the increase of activity.Although the activity of CeYMn catalyst decreases after aging at 800℃,it is still higher than that of other catalysts aged at 700℃.
基金financially supported by the Nation Key R&D Program China (2022YFB3603804)Natural Science Foundation of Shanghai (22ZR1407800)Postdoctoral Science Foundation of China (2021M700800)。
文摘High-temperature stability of organic field-effect transistors(OFETs)is critical to ensure its long-term reliable operation under various environmental conditions.The molecular packing of donor-acceptor(D-A)conjugated polymers is closely related to the electrical performance stability in OFETs.Herein,we choose poly[[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)]as a modal system to reveal the relationship between the molecular stacking and electrical stability in high-temperature environment.The results demonstrate that the films with D-A moieties in alternate stacking have better electrical thermal stability compared to normal donor-donor(D-D)stacking.The D-A stacking configuration alternates donor and acceptor units along the out-of-plane direction,while the D-D stacking involves D-D and A-A stacking separately.The structural transition from D-D to D-A is captured at a treated temperature range of 225±250°C.Owing to the tighter packing arrangement along theπ-πand lamellar directions,the electron mobility of the D-A stacked films reaches up to 0.23 cm^(2)/V·s,a 50%increase as compared to the D-D stacking films.Furthermore,the D-A stacked films indicate superior electrical performance stability with mobility retaining 100%at 250°C during high-temperature cycling tests.This result highlights that the manipulation of conjugated polymer closely stacked structures can significantly enhance the thermal stability and durability of semiconductor devices.
基金supported by the National Natural Science Foundation of China(No.52173261)the Science and Technology on Advanced Functional Composites Laboratory(No.6142906240505).
文摘Porous SiBCN ceramics exhibit great potential in high-tech structural and functional applications. However, nucleation-crystallization and carbothermal decomposition limit their use in high-temperature environments. Herein, high-entropy carbide (HEC) (Ti_(0.25)Zr_(0.25)Hf_(0.25)Ta_(0.25))C-modified porous SiBCN ceramics (HEC/SiBCN) were successfully fabricated from a multi-metal (Ti,Zr,Hf,Ta) precursor containing polyborosilazane via solvothermal methods, freeze-drying, and pyrolysis. The porous HEC/SiBCN ceramic possesses tailorable porosity (63.5%–79.1%), low thermal conductivity (0.054–0.089 W/(m·K)), and good mechanical strength. The HEC phase is in situ formed by carbothermal reduction and solid solution reaction of the multicomponent precursor with highly active free carbon in the SiBCN matrix during the pyrolysis, which endows the porous HEC/SiBCN ceramics with outstanding thermal stability up to 1800℃. The in situ formation of the HEC phase provides novel insight and a promising strategy for enhancing the overall performance of porous SiBCN ceramics, expanding their application in high-temperature environments.
基金supported by Beijing Institute of Technology Student Innovation Training Program(BIT2024LH013).
文摘The thermal stability of lithium-ion battery separators is a critical determinant of battery safety and performance,especially in the context of rapidly expanding applications in electric vehicles and energy storage systems.While traditional polyolefin separators(PP/PE)dominate the market due to their cost-effectiveness and mechanical robustness,their inherent poor thermal stability poses significant safety risks under high-temperature conditions.This review provides a comprehensive analysis of recent advancements in enhancing separator thermal stability through coating materials(metal,ceramic,inorganic)and novel high-temperature-resistant polymers(e.g.,PVDF copolymers,PI,PAN).Notably,we critically evaluate the trade-offs between thermal resilience and electrochemical performance,such as the unintended increase in electronic conductivity from metal coatings(e.g.,Cu,MOFs)and reduced electrolyte wettability in ceramic coatings(e.g.,Al_(2)O_(3)).Innovations in hybrid coatings(e.g.,BN/PAN composites,gradient-structured MOFs)and scalable manufacturing techniques(e.g.,roll-to-roll electrospinning)are highlighted as promising strategies to balance these competing demands.Furthermore,a comparative analysis of next-generation high-temperature-resistant separators underscores their ionic conductivity,mechanical strength,and scalability,offering actionable insights for material selection.The review concludes with forward-looking perspectives on integrating machine learning for material discovery,optimizing interfacial adhesion in ceramic coatings,and advancing semi-/all-solid-state batteries to address both thermal and electrochemical challenges.This work aims to bridge the gap between laboratory innovations and industrial applications,fostering safer and more efficient lithium battery technologies.
基金supported by the National Natural Science Foundation of China(No.52102132)the Natural Science Foundation of Shandong Province of China(Nos.ZR2024ME201 and ZR2021ME085)+1 种基金the Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices(No.EFMD2023001M)the Natural Science Foundation of Heilongjiang Province(No.LH2022E049).
文摘BaTiO_(3) (BT)-based piezoceramics with large temperature-stable strains and low hysteresis are urgently needed for high-precision actuators because of increasing environmental problems. Here, tetragonal [001]c-textured (Ba_(0.98)Ca_(0.02))(Ti_(0.96)Sn_(0.04))O_(3) (BCTS) ceramics with a texture degree (F_(001)) of ~98% were obtained via the templated grain growth (TGG) method. A large maximum unipolar strain (S_(max)) of ~0.24% with a low strain hysteresis (Hs) of ~3.8% and an optimized piezoelectric strain coefficient (d_(33)^(*)) of ~1124 pm·V^(−1) are simultaneously achieved in the textured BCTS ceramics. Moreover, the variation in the strain response is less than 20% from room temperature (RT) to 100℃ for the textured ceramics. The underlying mechanism for the optimized strain performance could be attributed to the synergetic effect of the polarization extension and a fine domain structure. This work provides new insight for achieving a balance of multiple strain properties (large strain, low hysteresis, and high-temperature stability) in BT-based ceramics, showing the widespread application prospects of lead-free ceramics in high-precision actuators.
基金This research is sponsored by the National Natural Science Foundation of China (Grant No. 51971156)National Science and Technology Major Project (Grant No. 2017-VII-0007).
文摘Sc was doped into Gd_(2)Zr_(2)O_(7) for expanding the potential for thermal barrier coating (TBC) applications. The solid solution mechanism of Sc in the Gd_(2)Zr_(2)O_(7) lattice, and the mechanical and thermophysical properties of the doped Gd_(2)Zr_(2)O_(7) were systematically studied by the first-principles method, based on which the Sc doping content was optimized. Additionally, Sc-doped Gd_(2)Zr_(2)O_(7) TBCs with the optimized composition were prepared by air plasma spraying using YSZ as a bottom ceramic coating (Gd-Sc/YSZ TBCs), and their sintering behavior and thermal cycling performance were examined. Results revealed that at low Sc doping levels, Sc has a large tendency to occupy the lattice interstitial sites, and when the doping content is above 11.11 at%, Sc substituting for Gd in the lattice becomes dominant. Among the doped Gd_(2)Zr_(2)O_(7), the composition with 16.67 at% Sc content has the lowest Pugh’s indicator (G/B) and the highest Poisson ratio (σ) indicative of the highest toughness, and the decreasing trends of Debye temperature and thermal conductivity slow down at this composition. By considering the mechanical and thermophysical properties comprehensively, the Sc doping content was optimized to be 16.67 at%. The fabricated Gd-Sc coatings remain phase and structural stability after sintering at 1400 ℃ for 100 h. Gd-Sc/YSZ TBCs exhibit excellent thermal shock resistance, which is related to the good thermal match between Gd-Sc and YSZ coatings, and the buffering effect of the YSZ coating during thermal cycling. These results revealed that Sc-doped Gd_(2)Zr_(2)O_(7) has a high potential for TBC applications, especially for the composition with 16.67 at% Sc content.
基金This research was funded by the Scientific Research Fund of Yunnan Provincial Department of Education(Grant No.2020J0420)Open Fund based on Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products(Grant No.2015004).In addition,the authors would like to thank the reviewers of this paper for their ever-present support and valuable advice.
文摘The use of lignin,which is a by-product of the pulp and paper industry,in the development of asphalt binders would contribute to waste reduction,providing environmental,economic,and social benefits.In this study,samples of lignin-modified asphalt binder samples with different content of lignin(3%,6%,9%,12%,and 15%)and unmodified asphalt(control)were tested using Fourier transform infrared spectroscopy(FTIR),dynamic shear rheometer(DSR),and thermogravimetry.The mechanism and effectiveness of lignin in improving the thermal stability of asphalt at high temperatures were analyzed.The FTIR analysis shows that no new characteristic absorption peak is seen in the infrared spectral of the lignin-modified asphalt binder samples,and some bands characteristic of lignin-related peaks gradually increased with the increase of lignin content.This suggests that the modification of lignin-modified asphalt binder samples was due to physical blending rather than chemical modification.The increase of lignin content in the lignin-modified asphalt samples increases the complex shear modulus G*of the samples and decreases the phase angles of the samples.Similarly,the anti-rutting performance(G*/sinδ)of the samples improves with the increase in lignin content,but this is not significant after any addition of lignin that exceeds 12%of asphalt mass.Thermal characterizations show that the thermal decomposition rate of lignin is lower,and its residual amount is higher compared to that of asphalt,which is a major reason for the improved stability of lignin-modified asphalt binders at high temperatures.The effect of lignin on the thermal stability of asphalt is dependent on both lignin content and temperature.It has a positive effect on the thermal stability of asphalt at high temperatures within the range of asphalt service temperature(25℃–200℃).Additionally,from the pyrolysis viewpoint,it was explained that excessive lignin addition is not beneficial to the thermal stability of asphalt at high temperatures,which is consistent with the DSR test result conducted high temperatures.
基金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To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金Supported by National Natural Science Foundation of China(12201118)Guangdong Basic and Applied Basic Research Foundation(2023A1515010706)。
文摘We investigate a class of non-integrable two-particle Calogero-Moser systems modulated by a power-law external potential.The local well-posedness of the Cauchy problem is established under the strict initial separation condition for the particles.For suitably prepared initial configurations,local solutions can be extended globally via energy conservation;conversely,negative energy conditions induce(in)finite-time blowup.The linear(in)stability of stationary solutions is analyzed,with their energy serving as a threshold.Numerical investigations employ a fourth-order Runge-Kutta scheme with adaptive step-size control.Simulations demonstrate that the trajectories either converge to steady states or exhibit blowup,depending on the power exponent α and initial conditions.Increasingαaccelerates the convergence rate and dampens oscillatory dynamics,promoting a transition from periodic behavior to static equilibrium.
文摘Quantitative real-time PCR(qPCR)is widely used for gene expression analysis,but its accuracy critically depends on stable internal reference genes for normalization.In marine invertebrates,especially non-model taxa such as cephalopods,systematic evaluation of reference genes is limited,leading to potential bias.The cuttlefish Sepiella japonica is ecologically and economically important in China,yet previous molecular studies have often relied on single unvalidated reference genes,which may compromise data reliability.This study aimed to systematically evaluate the stability of five commonly used reference genes(18S,ef-1α,ef-1γ,gapdh,andβ-actin)across multiple tissues and sexes of S.japonica,and to identify the most suitable reference genes and optimal number for qPCR normalization.Fifteen to sixteen tissue types were collected from ten healthy adults(five males and five females).Total RNA was extracted,reverse-transcribed,and analyzed by qPCR.Gene stability was assessed using four algorithms(geNorm,NormFinder,BestKeeper,andΔCt)integrated with RefFinder,and the optimal gene number was determined using geNorm pairwise variation(V_(n/n+1)<0.15).Four transcriptome-derived genes(creld2,cd109,acy1,and miox)were used for validation.The C_(t)values of the five genes ranged from 15.47 to 20.83.β-actin and gapdh showed pronounced variability in expression stability among tissues and sexes,indicating their limited suitability for normalization.18S exhibited the highest expression(mean C_(t):15.47-16.29)and lowest variability but displayed sex-biased expression,whereas ef-1αand ef-1γremained consistently stable across most tissues in both sexes,with ef-1αbeing the most robust and showing no sex-related bias.Although specific rankings varied among tissues and sexes,the comprehensive results indicated that ef-1αand ef-1γpossessed the highest overall stability,followed by 18S,whileβ-actin and gapdh were the least stable.The final comprehensive rankings were ef-1γ>ef-1α>18S>gapdh>β-actin(male)and ef-1α>ef-1γ>18S>gapdh>β-actin(female).geNorm analysis(V2/3<0.15)indicated that two genes,mainly ef-1αand ef-1γ,were generally sufficient for reliable normalization in most tissues.Validation confirmed that normalization using the stable ef-1αand ef-1γaccurately reflected the expression differences among tissues,whereasβ-actin and gapdh can bias or confound statistical analyses.ef-1αand ef-1γare identified as the most reliable reference gene combination for qPCR analysis in S.japonica,while 18S can serve as an auxiliary gene for within-sex comparisons.The use ofβ-actin or gapdh alone is not recommended.This study establishes a systematic framework for selecting reliable reference genes in S.japonica,thereby facilitating robust qPCR normalization and providing a foundation for future gene expression research in S.japonica and other cephalopods.
基金supported by the Key R&D Program of Shandong Province,China(No.2025CXGC 010412)the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(No.U21A2048).
文摘The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
基金National Natural Science Foundation of China(No.U2241205)the Natural Science Basic Research Program of Shaanxi(Nos.2022JC-33,2023-GHZD-35,and 2024JC-ZDXM-25)+1 种基金the Fundamental Research Funds for the Central Universitiesthe National 111 Project to provide fund for conducting experiments。
文摘In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.
基金financially supported by the National Natural Science Foundation of China(Nos.52472032 and 52172023)the Key Program of Natural Science Foundation of Hubei Province(No.2024AFA083)
文摘High-temperature industries,as the primary consumers of energy,are greatly concerned with energy savings.Designing refractory linings with low thermal conductivity to reduce heat dissipation through high-temperature furnace linings is a critical concern.In this study,a series of novel entropy-stabilized spinel materials are reported,and their potential applications in high-temperature industries are investigated.XRD and TEM results indicate that all materials possess a cubic spinel crystal structure with the■space group.Furthermore,these materials exhibit good phase stability at high temperatures.All entropy-stabilized spinel aggregates demonstrated high refractoriness(>1800℃)and a high load softening temperature(>1700℃).The impact of configurational entropy on the properties of entropy-stabilized spinel materials was also studied.As configurational entropy increased,the thermal conductivity of the entropy-stabilized spinel decreased,while slag corrosion resistance deteriorated.For the entropy-stabilized spinel with a configurational entropy value of 1.126R,it showed good high-temperature stability,reliable resistance to slag attack,and a low thermal conductivity of 2.776 W·m^(-1)·K^(-1)at 1000℃.
基金funding support from the National Natural Science Foundation of China(Nos.52304101 and 52204153)the China Postdoctoral Science Foundation(No.2023MD734215)+2 种基金the Youth Talent Support Program of Xi’an Association for Science and Technology(No.959202413070)the Key Research and Development Program of Shaanxi(No.2023-LL-QY-07)the Key Research and Development Program of Zhejiang(No.2023C03182).
文摘Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional assumption that the fill material exhibits a significantly lower stiffness than the host rocks.Significantly,a recent pioneering work revealed the time-dependent ground stability around a backfilled stope with vertical walls through numerical modeling.In practice,underground stopes typically exhibit a higher or lower degree of inclination.This alters the stress state in peripheral rocks and may induce severe instability and dilution,particularly in stope-hanging walls.Hence,it is imperative to analyze the time-dependent ground stability of inclined backfilled stopes for backfill structure design.Therefore,comprehensive numerical simulations were performed using FLAC3D to address this knowledge deficiency by incorporating a coupled analysis of the backfill consolidation behavior and long-term creep deformation in surrounding rocks.The ground stability was evaluated based on the confinement effectiveness,strength-stress ratio,stress path relative to the yield surface,and time-dependent stress redistribution in the rocks.A parametric study revealed that the inclination angle of the backfilled stope reduced the confinement effectiveness in the host rocks when the wall creep was minor.This exacerbated the rock mass sloughing potential.However,a backfilled stope with a shallower dip angle achieved superior ground stability enhancement when the creep deformation was substantial,by applying a more significant compression on the backfill and effectively mobilizing its passive support performance during consolidation.Additional simulations were conducted to analyze the effects of stope height and width,mine depth,mechanical properties of rocks,backfill compressibility,and filling gap on the time-dependent stress redistribution and stability around the inclined backfilled stope.
文摘AIM:To investigate the effects of binocular fusional C-optotypes(positive/negative)and 2D planar C-optotypes on the amplitude and stability of transient accommodation(TAC)in adults,and to provide a basis for non-contact myopia intervention.METHODS:This was a self-controlled study.Using redblue 3D technology,four experimental stages were set up:Test A[fixating on the 1 m negative fusional C-optotypes,8△base-in(BI)],Test B(fixating on the 5 m planar C-optotypes),Test C(fixating on the 1 m planar C-optotypes),and Test D[fixating on the 1 m positive fusional C-optotypes,20△base-out(BO)].A WAM-5500 open-field autorefractor was used to measure TAC and accommodative microfluctuations[evaluated via interquartile range(IQR)and median-based coefficient of variation(CVmed)].Additionally,the convergence accommodation to convergence(CA/C)ratio was calculated,and a visual fatigue questionnaire was administered to assess participants’subjective visual comfort.RESULTS:A total of 21 subjects(7 males,14 females;aged 23-41y)with normal binocular visual function were enrolled.The results showed that the TAC increased gradually across the four stages,and these values were Test A(-0.35±0.26 D)<Test B(-0.46±0.24 D)<Test C(-0.77±0.32 D)<Test D(-1.38±0.31 D).There were significant overall differences(F=56.136,P<0.001).Compared with Test C,Test A reduced TAC by 0.42 D(P<0.05),while Test D increased it by 0.61 D(P<0.001).There was no significant intergroup difference in accommodative fluctuation amplitude(all P>0.05),but the fluctuation stability of Test D showed a significant difference between the first 20s and the second 20s(P=0.017).The CA/C ratio was significantly higher in Test D(0.05±0.02 D/△)than in Test A(0.03±0.02 D/△,P=0.007),indicating stronger accommodation-convergence linkage during positive fusional fixation.The visual fatigue scores of all stages were low(median 0-1),with Test D slightly higher than Test B and Test C(P<0.05).No linear correlation was found between TAC and age(all r<0.1,P>0.05).CONCLUSION:Negative fusional C-optotypes induce ciliary muscle relaxation to reduce TAC,while positive fusional C-optotypes enhance accommodation-convergence coordination to increase TAC.The red-blue 3D-based noncontact training mode exhibits good safety(median visual fatigue scores:0-1 across all tests)and provides a novel dual-directional(relaxation-activation)strategy for myopia prevention and control.
