Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivativ...Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.展开更多
This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The dat...This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.展开更多
Interactions between cement clinkers and clay minerals are crucial to the much lower strength of cement-based stabilized clays than concrete or mortar.In this paper,the kaolinite-based and montmorillonite-based clays ...Interactions between cement clinkers and clay minerals are crucial to the much lower strength of cement-based stabilized clays than concrete or mortar.In this paper,the kaolinite-based and montmorillonite-based clays were respectively stabilized by tricalcium silicate(C3S)and tricalcium aluminate(C3A),and measured by the unconfined compressive strength(UCS),29Si/27Al solid state nuclear magnetic resonance(SS-NMR),Fourier transform infrared spectroscopy(FTIR),and transmission electron microscope(TEM)to probe the clinker-clay mineral interaction from macro-mechanical,mineralogical,and microstructural perspectives.The results show that C3A-stabilized samples gain strength rapidly in the first 3 d but are only 20%e60%of the strength of C3S-stabilized ones after 60 d.Microstructures reveal that montmorillonite shows better pozzolanic reactivity due to its superior Sichain and lattice substitution compared to kaolinite.This interaction domains the engineering performance of stabilized clays,benefiting the design of stabilizer referring to as the industrial by-products and clay minerals.展开更多
Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycli...Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.展开更多
Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions o...Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.展开更多
Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the mu...Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.展开更多
Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool ...Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool to evaluate the Pb-contaminated soils stabilized by electrolytic manganese residue(EMR)-based geopolymer(EG-OPC)from the strength and environmental benefits perspective.First,unconfined compressive strength(UCS)and leaching tests were conducted to study the stabilization effectiveness of EG-OPC.Results indicated that the UCS values of soil(5000 mg/kg of pollutants)stabilized by 20%EG-OPC were 4.87 MPa and 8.13 MPa after 7 d and 60 d of curing,respectively.After 60 d of curing,the Pb concentration in the leachate reached 44 mg/L,far lower than the control group(321 mg/L).Second,soil,pore water,and leachate resistivity(ERS,ERW,and ERL)were measured to establish fitting relationships with strength parameters and pollution risk.The good fitting results(e.g.ERS/ERW versus UCS/secant modulus(E50):correlation coefficient R2 z 0.9,ERS/ERW versus Pb contents:R2 z 0.9,and ERL versus Pb2þconcentration:R2¼0.92)and well used Archie's law(ERS versus ERW:R2>0.9)indicate that the resistivity can be used to evaluate the stabilization effectiveness.Furthermore,the microscopic results revealed two behaviors,demonstrating the reliability of resistivity:(1)with the hydration process,resistivity increases due to a denser structure and lower amounts of free water and Pb ions,and(2)the addition of Pb reduces resistivity due to its inhibition or even destructive effects on cementation and formation of hydration products.展开更多
Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-hea...Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-heating method reached 39.70%±0.01% under the optimal conditions of MPI/DX mass ratio 1:2.3,reaction temperature 58.8℃,and reaction time 4 d.Moreover,the analyses of Fourier infrared spectroscopy,intrinsic fluorescence spectroscopy,surface hydrophobicity,and thermal stability further confirmed the covalent grafting of dextran onto MPI molecules.When encapsulated in MDC NEs at 80 MPa for three times by highpressure homogenization,the encapsulation efficiency and loading capacity of HES were 63.62%±0.01%and 0.40±0.00 g/g,respectively.The encapsulated HES exhibited higher antioxidant activity and stronger light and storage stability than the free HES.Additionally,the incorporation of HES inhibited the formation of lipid peroxides in the nanoemulsions.The findings suggest that glycosylation combined with high-pressure homogenization is an effective strategy for enhancing the stability of MPI-based emulsions and improving their encapsulation of HES.This study provides a promising approach for the development of innovative food and beverage products based on MPI emulsions or new materials for encapsulating fat-soluble bioactive compounds.展开更多
The traditional cement-based stabilization cannot effectively stabilize the marine soft clay under submerged conditions.In order to solve this problem,the enhancement of cement-stabilized marine soft clay was investig...The traditional cement-based stabilization cannot effectively stabilize the marine soft clay under submerged conditions.In order to solve this problem,the enhancement of cement-stabilized marine soft clay was investigated in this study by adding the ionic soil stabilizer(ISS)and polyacrylamide(PAM).For this purpose,varying contents of ISS and PAM(ISS-P)were added into cement-stabilized marine soft clay and subjected to curing under submerged conditions.Atterberg limits tests,direct shear tests,unconfined compression strength(UCS)tests,water-stability tests,scanning electron microscopy analysis,and X-ray diffraction analysis were carried out.The results show that using 1.8%ISS and 0.9%PAM as the optimal ratio,the cohesion,internal friction angle,UCS,and water-stability of the samples increased by 182.7%,15.4%,176.5%,and 368.5% compared to the cement-stabilized soft clay after 28 d.The increment in soil cohesion with increasing ISS-P content was more apparent than that in the internal friction angle.The combined action of ion exchange attraction and electrostatic adsorption altered the failure characteristics of the samples,resulting in localized micro-cracking and multiple failure paths.Increasing the content of ISS-P strengthened the skeletal structure of soil,reduced inter-particle spacing,and enhanced the water-stability.Additionally,ISS promotes the hydration of cement and compensates for the inhibitory effect of PAM on early cement hydration.ISS-P can effectively enhance the strength and stability of submerged cement-based stabilized marine soft clay.展开更多
The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil im...The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil improvement is an important aspect of sustainable and environmentally-conscious geotechnical engineering when marginal usage of lime and concrete is of great interest to engineers and societies.Currently,discussion is predominantly focused on the positive aspects of using the F-class FA,with a paucity of emphasis on the negative aspects.To explore these features more thoroughly,a series of strength and compressibility tests was conducted.The sample preparation and curing methodology were chosen to replicate the in situ conditions where soil is surcharged and submerged in water.It was found that the incorporation of F-class FA without an activator reduces the undrained shear strength of submerged orSi by about 20%–25%and permanently prevents any thixotropic strength restoration.An increase in undrained shear strength is observed when lime(3%–6%)is added to the soil–FA mixture or when only lime(in the same amount of 3%–6%)is used.Consequently,F-class FA can be successfully used as a filler for slurries with minimum lime content in soil mixing methods.The F-class FA(with or without an activator)shifts the so-called“creep delay”in time,consequently reducing the total creep settlements.The shift of“creep delay”is more considerable for orSi stabilized with lime or with FA and lime as an activator,than for orSi stabilized with pure F-class FA.展开更多
Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.I...Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.展开更多
Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation...Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation.These issues accelerate capacity fading,exacerbate interfacial polarization,and compromise safety.To address these issues,we proposed a scalable CeF_(3)/H_(3)BO_(3)hybrid coating strategy for LiNi_(0.82)Co_(0.12)Mn_(0.06)O_(2)cathodes.The CeF_(3)nanoparticles served as a robust physical barrier,effectively scavenging HF,while the LiBO_(2)layer derived from H_(3)BO_(3)eliminated residual Li_(2)CO_(3)through chemical conversion and established rapid Li^(+)transport pathways.Dynamic B-O bond reorganization enabled self-repair of coating defects,synergistically suppressing interfacial polarization and maintaining structural integrity.Electrochemical evaluations demonstrated that the hybridcoated cathode achieves 94%capacity retention after 200 cycles at 1C(2.8-4.3 V),significantly outperforming the pristine NCM(56.3%).Additionally,the modified cathode exhibits enhanced air stability,with suppressed H_(2)O/CO_(2)infiltration,and delivers 80%capacity retention after 1000 cycles in practical pouch cells.This work provides a costeffective and industrially viable solution to simultaneously mitigate HF corrosion,residual lithium accumulation,and cathode-electrolyte interphase instability,paving the way for durable high-energy-density batteries.展开更多
Composite ceramics thermal barrier coatings(TBCs) are widely used in the aero-engines field due to their excellent thermal insulation, which improves the service life and durability of the inherent hot components. The...Composite ceramics thermal barrier coatings(TBCs) are widely used in the aero-engines field due to their excellent thermal insulation, which improves the service life and durability of the inherent hot components. The most typical, successful and widely used TBCs material is yttria stabilized zirconia(YSZ). In this paper, fabrication methods, coating structures, materials, failure mechanism and major challenges of YSZ TBCs are introduced and reviewed. The research tendency is put forward as well. This review provides a good understanding of the YSZ TBCs and inspires researchers to discover versatile ideas to improve the TBCs systems.展开更多
In the field of soil stabilization, only calcium silicate hydrate(CSH) and ettringite(AFt) as hydration products have been reported to directly contribute to the strength enhancement of the soil. A chloride dredger fi...In the field of soil stabilization, only calcium silicate hydrate(CSH) and ettringite(AFt) as hydration products have been reported to directly contribute to the strength enhancement of the soil. A chloride dredger fill, an artificial chloride saline soil, and a non-saline soil were stabilized by Portland cement(PC) and PC with Ca(OH)_2(CH) with different contents. A series of unconfined compressive strength(UCS) tests of stabilized soil specimen after curing for 7 d and 28 d were carried out, and the hydration products and microstructure of the specimens were observed by X-ray diffractometry(XRD), scanning electronic microscopy(SEM), and energy-dispersive X-ray analysis(EDXA). The results showed that the strengths of PC+CH-stabilized chloride saline soils were much higher than those of PC-stabilized soils. A new hydration product of calcium aluminate chloride hydrate, also known as Friedel's salt, appeared in the PC+CH-stabilized chloride saline soils. The solid-phase volume of Friedel's salt expanded during the formation of the hydrate; this volume filled the pores in the stabilized soil. This pore-filling effect was the most important contribution to the significantly enhanced strength of the PC+CH-stabilized chloride saline soils. On the basis of this understanding, a new optimized stabilizer was designed according to the concept that the chloride in saline soil could be utilized as a component of the stabilizer. The strength of the chloride saline soils stabilized by the optimized stabilizer was even further increased compared with that of the PC+CH-stabilized soils.展开更多
Aqueous zinc-ion batteries(ZIBs) combine the benefits of metallic Zn anodes with those of aqueous electrolytes and are well suited for large-scale energy storage because of their inherent high safety, cost-effectivene...Aqueous zinc-ion batteries(ZIBs) combine the benefits of metallic Zn anodes with those of aqueous electrolytes and are well suited for large-scale energy storage because of their inherent high safety, cost-effectiveness, and eco-friendliness. Currently, the practical application of such batteries is hindered by the poor cycling performance of Zn anodes due to uncontrolled dendrite formation and severe side reactions, although recent reports suggest that these problems can be mitigated through the modification of Zn anodes with metal-based materials.Given that the mechanisms of improving Zn deposition and the structural evolution of metal-based materials have not been systematically reviewed, we herein systematically overview the metal-based materials used to stabilize Zn anodes, starting with a brief summary of the anode working mechanism and the challenges faced by stabilized Zn anodes. Subsequently, the design principles of Zn anodes stabilized by metal-based materials and the related recent progress are reviewed, and the key challenges and perspectives for the future development of such Zn anodes are proposed.展开更多
Nanostructured yttria partially stabilized zirconia(YSZ) coatings were prepared by atmospheric plasma spraying(APS) using the conglomeration made by zirconia nanoparticle as the raw materials.The measurement methods,w...Nanostructured yttria partially stabilized zirconia(YSZ) coatings were prepared by atmospheric plasma spraying(APS) using the conglomeration made by zirconia nanoparticle as the raw materials.The measurement methods,which consisted of scanning electron microscopy(SEM),transmission electron microscopy(TEM) and thermal cycling behavior,were used to character the morphology,composition and thermal oxidation behavior of the powder and the coatings.From the results,it was shown that the YSZ coating was the laminar structure,and the elements distribution in the bond and top coat were well-proportioned.The YSZ coatings were composed of fine grains with size ranging from 30 to 110 nm.The laminar layers with columnar grains were surrounded with unmelted parts of the nanostructured powder and some equiaxed grains.In the as-sprayed nanostructured zirconia coatings,there existed pores that were less than 1 μm.The cracks were observed on some of the crystal border.The cyclic oxidation experiment showed that the nanostructured coating had longer thermal cycling lifetime to exhibit the promising thermal cyclic oxidation resistance.The failure of the nanostructured TBC was similar to the failure of conventional APS TBC.展开更多
To overcome the influence of the nonlinear friction on the gimbaled servo-system of an inertial stabilized platforms(ISPs)with DC motor direct-drive,the methods of modeling and compensation of the nonlinear friction a...To overcome the influence of the nonlinear friction on the gimbaled servo-system of an inertial stabilized platforms(ISPs)with DC motor direct-drive,the methods of modeling and compensation of the nonlinear friction are proposed.Firstly,the inapplicability of LuGre model when trying to interpret the backward angular displacement in the prestiction regime is observed experimentally and the reason is deduced theoretically.Then,based on the dynamic model of direct-drive ISPs,a modified LuGre model is proposed to describe the characteristic of the friction in the prestiction regime.Furthermore,the state switch condition of the three friction regimes including presliding,gross sliding and prestiction is presented.Finally,a composite compensation controller including a nonlinear friction observer and a feedforward compensator based on the novel LuGre model is designed to restrain the nonlinear friction and to improve the control precision.Experimental results indicate that compared with those of the conventional proportion-integrationdifferentiation(PID)control method and the PID plus LuGre model-based friction compensation method,the dwell-time has decreased from 0.2 s to almost 0 s,the position error decreased to 86.7%and the peak-to-peak value of position error decreased to 80%after the novel compensation controller is added.It concludes that the composite compensation controller can greatly improve the control precision of the dynamic sealed ISPs.展开更多
The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leaka...The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leakageproofing method.In this study,a novel carbonized Cu-coated melamine foam(MF)/reduced graphene oxide(rGO)framework(MF/rGO/Cu-C)is constructed as a support for fabricating stabilized multifunctional OPCMs.MF serves as the supporting material,while rGO and Cu act as functional reinforcements.As a thermal energy storage material,polyethylene glycol(PEG)is encapsulated into MF/rGO/Cu-C through a vacuum-assisted impregnation method to obtain PEG@MF/rGO/Cu-C composite with excellent comprehensive performance.PEG@MF/rGO/Cu-C exhibits high phase change enthalpies of 148.3 J g^(-1)(melting)and 143.9 J g^(-1)(crystallization),corresponding to a high energy storage capability of 92.7%.Simultaneously,MF/rGO/Cu-C endues the composite with an enhanced thermal conductivity of 0.4621Wm^(-1) K^(-1),which increases by 463%compared to that of PEG@MF.Furthermore,PEG@MF/rGO/Cu-C displays great light-to-thermal and electric-to-thermal conversion capabilities,thermal cycle stability,light-tothermal cycle stability,and shape stability,showing promising application prospects in different aspects.展开更多
The performance of any inertially stabilized platform （ISP） is strongly related to the bandwidth and accuracy of the angular velocity signals. This paper discusses the development of an optimal state estimator for s...The performance of any inertially stabilized platform （ISP） is strongly related to the bandwidth and accuracy of the angular velocity signals. This paper discusses the development of an optimal state estimator for sensing inertial velocity using low-cost micro-electro-mechanical systems （MEMS） sensors. A low-bandwidth gyroscope is used alone with two low-performance accelerometers to obtain the estimation. The gyroscope has its own limited dynamics and mainly contributes to the low-frequency components of the estimation. The accelerometers have inherent biases and mainly contribute to the high-frequency components of the estimation. Extensive experimental results show that the state estimator can achieve high-performance signals over a wide range of velocities without drifts in both the t- and s-domains. Furthermore, with applications in miniature inertially stabilized platforms, the control characteristic presents a significantly improvement over the existing methods. The method can be also applied to robotics, attitude estimation, and friction compensation.展开更多
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
文摘Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.
基金the financial support of the National Natural Science Foundation of China(Nos.U2141221 and 52076136)the National Science and Technology Major Project,China(Nos.J2019-Ⅲ-0004-0047 and Y2022-Ⅲ-0001-0010)+1 种基金the Center for Basic Science of Aero Engines and Gas Turbines Project,China(No.P2022-B-Ⅱ019-001)the Natural Science Foundation of Shanghai,China(Nos.22ZR1467900 and 23ZR1481400)。
文摘This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.
基金supported by the National Natural Science Foundation of China(Grant Nos.52278334,42272322,and 52209136).
文摘Interactions between cement clinkers and clay minerals are crucial to the much lower strength of cement-based stabilized clays than concrete or mortar.In this paper,the kaolinite-based and montmorillonite-based clays were respectively stabilized by tricalcium silicate(C3S)and tricalcium aluminate(C3A),and measured by the unconfined compressive strength(UCS),29Si/27Al solid state nuclear magnetic resonance(SS-NMR),Fourier transform infrared spectroscopy(FTIR),and transmission electron microscope(TEM)to probe the clinker-clay mineral interaction from macro-mechanical,mineralogical,and microstructural perspectives.The results show that C3A-stabilized samples gain strength rapidly in the first 3 d but are only 20%e60%of the strength of C3S-stabilized ones after 60 d.Microstructures reveal that montmorillonite shows better pozzolanic reactivity due to its superior Sichain and lattice substitution compared to kaolinite.This interaction domains the engineering performance of stabilized clays,benefiting the design of stabilizer referring to as the industrial by-products and clay minerals.
基金the W.M.Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona(Grant No.RRID:SCR_022884),with funding from the W.M.Keck Foundation Grant.
文摘Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.
文摘Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.
文摘Aim To study the effect of aerodynamically stabilized seeker dynamics on guided bomb system analysis. Methods A thorough analysis of aerodynamically stabilized seeker dynamics was made to show that because of the much smaller time constant, its dynamic model can be greatly simplified. Results and Conclusion In guided bomb guidance/control digital simulation, with the use of the simplified seeker model, simulation time can be reduced without the loss of simulation accuracy.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3901204)the Foundation for Distinguished Young Scholars of Hubei Province,China(Grant No.2021CFA096)the National Natural Science Foundation of China(Grant No.U20A20320).
文摘Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool to evaluate the Pb-contaminated soils stabilized by electrolytic manganese residue(EMR)-based geopolymer(EG-OPC)from the strength and environmental benefits perspective.First,unconfined compressive strength(UCS)and leaching tests were conducted to study the stabilization effectiveness of EG-OPC.Results indicated that the UCS values of soil(5000 mg/kg of pollutants)stabilized by 20%EG-OPC were 4.87 MPa and 8.13 MPa after 7 d and 60 d of curing,respectively.After 60 d of curing,the Pb concentration in the leachate reached 44 mg/L,far lower than the control group(321 mg/L).Second,soil,pore water,and leachate resistivity(ERS,ERW,and ERL)were measured to establish fitting relationships with strength parameters and pollution risk.The good fitting results(e.g.ERS/ERW versus UCS/secant modulus(E50):correlation coefficient R2 z 0.9,ERS/ERW versus Pb contents:R2 z 0.9,and ERL versus Pb2þconcentration:R2¼0.92)and well used Archie's law(ERS versus ERW:R2>0.9)indicate that the resistivity can be used to evaluate the stabilization effectiveness.Furthermore,the microscopic results revealed two behaviors,demonstrating the reliability of resistivity:(1)with the hydration process,resistivity increases due to a denser structure and lower amounts of free water and Pb ions,and(2)the addition of Pb reduces resistivity due to its inhibition or even destructive effects on cementation and formation of hydration products.
基金financially supported by the National Natural Science Foundation of China(Grant No.32101981)the cooperation project between Ya’an city and Sichuan Agricultural University(23ZDF0003)。
文摘Encapsulation and protection of hesperidin(HES)in mung bean protein isolate(MPI)-dextran(DX)conjugatestabilized nanoemulsions(MDC NEs)were investigated in this study.The degree of grafting of MDC prepared by a dry-heating method reached 39.70%±0.01% under the optimal conditions of MPI/DX mass ratio 1:2.3,reaction temperature 58.8℃,and reaction time 4 d.Moreover,the analyses of Fourier infrared spectroscopy,intrinsic fluorescence spectroscopy,surface hydrophobicity,and thermal stability further confirmed the covalent grafting of dextran onto MPI molecules.When encapsulated in MDC NEs at 80 MPa for three times by highpressure homogenization,the encapsulation efficiency and loading capacity of HES were 63.62%±0.01%and 0.40±0.00 g/g,respectively.The encapsulated HES exhibited higher antioxidant activity and stronger light and storage stability than the free HES.Additionally,the incorporation of HES inhibited the formation of lipid peroxides in the nanoemulsions.The findings suggest that glycosylation combined with high-pressure homogenization is an effective strategy for enhancing the stability of MPI-based emulsions and improving their encapsulation of HES.This study provides a promising approach for the development of innovative food and beverage products based on MPI emulsions or new materials for encapsulating fat-soluble bioactive compounds.
基金supported by the Fundamental Research Funds for the Central Universities(Nos.202061027,202261063)the National Natural Science Foundation of China(No.41572247)。
文摘The traditional cement-based stabilization cannot effectively stabilize the marine soft clay under submerged conditions.In order to solve this problem,the enhancement of cement-stabilized marine soft clay was investigated in this study by adding the ionic soil stabilizer(ISS)and polyacrylamide(PAM).For this purpose,varying contents of ISS and PAM(ISS-P)were added into cement-stabilized marine soft clay and subjected to curing under submerged conditions.Atterberg limits tests,direct shear tests,unconfined compression strength(UCS)tests,water-stability tests,scanning electron microscopy analysis,and X-ray diffraction analysis were carried out.The results show that using 1.8%ISS and 0.9%PAM as the optimal ratio,the cohesion,internal friction angle,UCS,and water-stability of the samples increased by 182.7%,15.4%,176.5%,and 368.5% compared to the cement-stabilized soft clay after 28 d.The increment in soil cohesion with increasing ISS-P content was more apparent than that in the internal friction angle.The combined action of ion exchange attraction and electrostatic adsorption altered the failure characteristics of the samples,resulting in localized micro-cracking and multiple failure paths.Increasing the content of ISS-P strengthened the skeletal structure of soil,reduced inter-particle spacing,and enhanced the water-stability.Additionally,ISS promotes the hydration of cement and compensates for the inhibitory effect of PAM on early cement hydration.ISS-P can effectively enhance the strength and stability of submerged cement-based stabilized marine soft clay.
基金supported by the Polish National Science Center(Grant No.2022/06/X/ST10/00320)received by Witold Tisler.
文摘The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil improvement is an important aspect of sustainable and environmentally-conscious geotechnical engineering when marginal usage of lime and concrete is of great interest to engineers and societies.Currently,discussion is predominantly focused on the positive aspects of using the F-class FA,with a paucity of emphasis on the negative aspects.To explore these features more thoroughly,a series of strength and compressibility tests was conducted.The sample preparation and curing methodology were chosen to replicate the in situ conditions where soil is surcharged and submerged in water.It was found that the incorporation of F-class FA without an activator reduces the undrained shear strength of submerged orSi by about 20%–25%and permanently prevents any thixotropic strength restoration.An increase in undrained shear strength is observed when lime(3%–6%)is added to the soil–FA mixture or when only lime(in the same amount of 3%–6%)is used.Consequently,F-class FA can be successfully used as a filler for slurries with minimum lime content in soil mixing methods.The F-class FA(with or without an activator)shifts the so-called“creep delay”in time,consequently reducing the total creep settlements.The shift of“creep delay”is more considerable for orSi stabilized with lime or with FA and lime as an activator,than for orSi stabilized with pure F-class FA.
基金supported by the Australian Research Council via Discovery Projects(Nos.DP200103315,DP200103332 and DP230100685)Linkage Projects(No.LP220200920)+1 种基金support from the IONTOF M6 ToF-SIMS(funded by ARC LIEF,LE190100053)the Kratos Axis Ultra XPS(ARC LIEF,LE120100026)。
文摘Ni-rich LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM)cathodes in layered oxide cathodes are attractive for high-energy lithium-ion batteries but suffer from rapid capacity fade and thermal instability at high charge voltages.In this study,we propose an entropy-assisted multi-element doping strategy to mitigate these issues.Specifically,two routes are designed and compared:bulk-like localized high-entropy doping(BHE-NCM)and surface-distributed high-entropy-zone doping(SHE-NCM).The surface entropy-doped NCM cathode delivers enhanced electrochemical performance,including higher capacity retention under 4.5 V cycling and superior rate capability,compared to both bulk-like and pristine counterparts.Comprehensive material characterization reveals that surface-localized doping stabilizes the layered structure with reduced microcrack formation and creates a uniform dopant-rich surface region with improved thermal and electrochemical stability.Overall,entropy-assisted doping at the near surface zone effectively alleviates structural degradation and interface reactions in Ni-rich NCM,enabling improved cycling performance at high voltage.This work highlights the significance of surface entropy engineering as a promising strategy for designing high-voltage cathodes with improved safety and longevity.
基金financially supported by the National Key Research and Development Program(No.2022YFC3900905)the National Natural Science Foundation of China(No.52234001)the Science and Technology Planning Project of Hunan Province(No.2018TP1017)
文摘Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation.These issues accelerate capacity fading,exacerbate interfacial polarization,and compromise safety.To address these issues,we proposed a scalable CeF_(3)/H_(3)BO_(3)hybrid coating strategy for LiNi_(0.82)Co_(0.12)Mn_(0.06)O_(2)cathodes.The CeF_(3)nanoparticles served as a robust physical barrier,effectively scavenging HF,while the LiBO_(2)layer derived from H_(3)BO_(3)eliminated residual Li_(2)CO_(3)through chemical conversion and established rapid Li^(+)transport pathways.Dynamic B-O bond reorganization enabled self-repair of coating defects,synergistically suppressing interfacial polarization and maintaining structural integrity.Electrochemical evaluations demonstrated that the hybridcoated cathode achieves 94%capacity retention after 200 cycles at 1C(2.8-4.3 V),significantly outperforming the pristine NCM(56.3%).Additionally,the modified cathode exhibits enhanced air stability,with suppressed H_(2)O/CO_(2)infiltration,and delivers 80%capacity retention after 1000 cycles in practical pouch cells.This work provides a costeffective and industrially viable solution to simultaneously mitigate HF corrosion,residual lithium accumulation,and cathode-electrolyte interphase instability,paving the way for durable high-energy-density batteries.
文摘Composite ceramics thermal barrier coatings(TBCs) are widely used in the aero-engines field due to their excellent thermal insulation, which improves the service life and durability of the inherent hot components. The most typical, successful and widely used TBCs material is yttria stabilized zirconia(YSZ). In this paper, fabrication methods, coating structures, materials, failure mechanism and major challenges of YSZ TBCs are introduced and reviewed. The research tendency is put forward as well. This review provides a good understanding of the YSZ TBCs and inspires researchers to discover versatile ideas to improve the TBCs systems.
基金Project(51008007)supported by the National Natural Science Foundation of ChinaProject(2013318J01100)supported by the Science and Technology Project of Ministry of Communications,China
文摘In the field of soil stabilization, only calcium silicate hydrate(CSH) and ettringite(AFt) as hydration products have been reported to directly contribute to the strength enhancement of the soil. A chloride dredger fill, an artificial chloride saline soil, and a non-saline soil were stabilized by Portland cement(PC) and PC with Ca(OH)_2(CH) with different contents. A series of unconfined compressive strength(UCS) tests of stabilized soil specimen after curing for 7 d and 28 d were carried out, and the hydration products and microstructure of the specimens were observed by X-ray diffractometry(XRD), scanning electronic microscopy(SEM), and energy-dispersive X-ray analysis(EDXA). The results showed that the strengths of PC+CH-stabilized chloride saline soils were much higher than those of PC-stabilized soils. A new hydration product of calcium aluminate chloride hydrate, also known as Friedel's salt, appeared in the PC+CH-stabilized chloride saline soils. The solid-phase volume of Friedel's salt expanded during the formation of the hydrate; this volume filled the pores in the stabilized soil. This pore-filling effect was the most important contribution to the significantly enhanced strength of the PC+CH-stabilized chloride saline soils. On the basis of this understanding, a new optimized stabilizer was designed according to the concept that the chloride in saline soil could be utilized as a component of the stabilizer. The strength of the chloride saline soils stabilized by the optimized stabilizer was even further increased compared with that of the PC+CH-stabilized soils.
基金financially supported by the National Natural Science Foundation of China (No.62101296)the Natural Science Foundation of Shaanxi Province (No.2021JQ-760 and 2021JQ-756)。
文摘Aqueous zinc-ion batteries(ZIBs) combine the benefits of metallic Zn anodes with those of aqueous electrolytes and are well suited for large-scale energy storage because of their inherent high safety, cost-effectiveness, and eco-friendliness. Currently, the practical application of such batteries is hindered by the poor cycling performance of Zn anodes due to uncontrolled dendrite formation and severe side reactions, although recent reports suggest that these problems can be mitigated through the modification of Zn anodes with metal-based materials.Given that the mechanisms of improving Zn deposition and the structural evolution of metal-based materials have not been systematically reviewed, we herein systematically overview the metal-based materials used to stabilize Zn anodes, starting with a brief summary of the anode working mechanism and the challenges faced by stabilized Zn anodes. Subsequently, the design principles of Zn anodes stabilized by metal-based materials and the related recent progress are reviewed, and the key challenges and perspectives for the future development of such Zn anodes are proposed.
基金Project supported by the National Defense Basic Scientific Research Program of China (K0504030206)
文摘Nanostructured yttria partially stabilized zirconia(YSZ) coatings were prepared by atmospheric plasma spraying(APS) using the conglomeration made by zirconia nanoparticle as the raw materials.The measurement methods,which consisted of scanning electron microscopy(SEM),transmission electron microscopy(TEM) and thermal cycling behavior,were used to character the morphology,composition and thermal oxidation behavior of the powder and the coatings.From the results,it was shown that the YSZ coating was the laminar structure,and the elements distribution in the bond and top coat were well-proportioned.The YSZ coatings were composed of fine grains with size ranging from 30 to 110 nm.The laminar layers with columnar grains were surrounded with unmelted parts of the nanostructured powder and some equiaxed grains.In the as-sprayed nanostructured zirconia coatings,there existed pores that were less than 1 μm.The cracks were observed on some of the crystal border.The cyclic oxidation experiment showed that the nanostructured coating had longer thermal cycling lifetime to exhibit the promising thermal cyclic oxidation resistance.The failure of the nanostructured TBC was similar to the failure of conventional APS TBC.
基金co-supported by the National Natural Science Foundation of China(Nos.51135009 and 51105371)
文摘To overcome the influence of the nonlinear friction on the gimbaled servo-system of an inertial stabilized platforms(ISPs)with DC motor direct-drive,the methods of modeling and compensation of the nonlinear friction are proposed.Firstly,the inapplicability of LuGre model when trying to interpret the backward angular displacement in the prestiction regime is observed experimentally and the reason is deduced theoretically.Then,based on the dynamic model of direct-drive ISPs,a modified LuGre model is proposed to describe the characteristic of the friction in the prestiction regime.Furthermore,the state switch condition of the three friction regimes including presliding,gross sliding and prestiction is presented.Finally,a composite compensation controller including a nonlinear friction observer and a feedforward compensator based on the novel LuGre model is designed to restrain the nonlinear friction and to improve the control precision.Experimental results indicate that compared with those of the conventional proportion-integrationdifferentiation(PID)control method and the PID plus LuGre model-based friction compensation method,the dwell-time has decreased from 0.2 s to almost 0 s,the position error decreased to 86.7%and the peak-to-peak value of position error decreased to 80%after the novel compensation controller is added.It concludes that the composite compensation controller can greatly improve the control precision of the dynamic sealed ISPs.
基金National Natural Science Foundation of China,Grant/Award Numbers:51861005,52071092,U20A20237Guangxi Natural Science Foundation,Grant/Award Numbers:2019GXNSFDA245023,2019GXNSFGA245005,2020GXNSFGA297004,2021GXNSFFA196002Guangxi Bagui Scholar Foundation。
文摘The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leakageproofing method.In this study,a novel carbonized Cu-coated melamine foam(MF)/reduced graphene oxide(rGO)framework(MF/rGO/Cu-C)is constructed as a support for fabricating stabilized multifunctional OPCMs.MF serves as the supporting material,while rGO and Cu act as functional reinforcements.As a thermal energy storage material,polyethylene glycol(PEG)is encapsulated into MF/rGO/Cu-C through a vacuum-assisted impregnation method to obtain PEG@MF/rGO/Cu-C composite with excellent comprehensive performance.PEG@MF/rGO/Cu-C exhibits high phase change enthalpies of 148.3 J g^(-1)(melting)and 143.9 J g^(-1)(crystallization),corresponding to a high energy storage capability of 92.7%.Simultaneously,MF/rGO/Cu-C endues the composite with an enhanced thermal conductivity of 0.4621Wm^(-1) K^(-1),which increases by 463%compared to that of PEG@MF.Furthermore,PEG@MF/rGO/Cu-C displays great light-to-thermal and electric-to-thermal conversion capabilities,thermal cycle stability,light-tothermal cycle stability,and shape stability,showing promising application prospects in different aspects.
基金Foundation item： National Natural Science Foundation of China （50805144）
文摘The performance of any inertially stabilized platform （ISP） is strongly related to the bandwidth and accuracy of the angular velocity signals. This paper discusses the development of an optimal state estimator for sensing inertial velocity using low-cost micro-electro-mechanical systems （MEMS） sensors. A low-bandwidth gyroscope is used alone with two low-performance accelerometers to obtain the estimation. The gyroscope has its own limited dynamics and mainly contributes to the low-frequency components of the estimation. The accelerometers have inherent biases and mainly contribute to the high-frequency components of the estimation. Extensive experimental results show that the state estimator can achieve high-performance signals over a wide range of velocities without drifts in both the t- and s-domains. Furthermore, with applications in miniature inertially stabilized platforms, the control characteristic presents a significantly improvement over the existing methods. The method can be also applied to robotics, attitude estimation, and friction compensation.
