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
As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather tha...As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).展开更多
Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(...Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.展开更多
Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors c...Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.展开更多
Pseudoephedrine (PSE) is a widely used nasal decongestant. A review by the European Medicines Agency has reported that PSE may be associated with risks of posterior reversible encephalopathy syndrome (PRES) and revers...Pseudoephedrine (PSE) is a widely used nasal decongestant. A review by the European Medicines Agency has reported that PSE may be associated with risks of posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS). PRES and RCVS are rare but serious conditions that affect cerebral blood flow. This review discusses the pharmacology of PSE and potential risks for PRES and RCVS and concludes that considering the common use of PSE, with over 70 million packs of PSE taken each year in the European Union and the United Kingdom, and the rare occurrence of PRES and RCVS, that the risks of developing PRES/RCVS on exposure to PSE are likely to be very low.展开更多
This paper, an addendum to “Dialectical Thermodynamics’ solution to the conceptual imbroglio that is the reversible path”, this journal, 10, 775-799, was written in response to the requests of several readers to pr...This paper, an addendum to “Dialectical Thermodynamics’ solution to the conceptual imbroglio that is the reversible path”, this journal, 10, 775-799, was written in response to the requests of several readers to provide further evidence of the said “imbroglio”. The evidence here presented relates to the incompatibility existing between the total-entropy and the Gibbs energy prescriptions for the reversible path. The previously published proof of the negentropic nature of the transformation of heat into work is here included to validate out conclusions about the Gibbs energy perspective.展开更多
BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involv...BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involves endothelial dysfunction,disrupted cerebral autoregulation,and resulting vasogenic edema.Hypertension and other factors that alter cerebral autoregulation are critical in its development.Corticosteroids,widely used for their anti-inflammatory and immunosuppressive properties,play a controversial role in PRES.AIM To elucidate the dual role of corticosteroids in the context of PRES by critically evaluating the existing literature.Specifically,it seeks to assess the results of PRES induced by corticosteroid therapy and the efficacy and safety of corticosteroids in the treatment of PRES.By synthesizing case reports and series,this review aims to provide a comprehensive understanding of the mechanisms,clinical presentations,and management strategies associated with corticosteroid-related PRES.METHODS The review was carried out according to the PRISMA guidelines.The databases searched included Science Direct,PubMed,and Hinari.The search strategy encompassed terms related to corticosteroids and PRES.Studies were included if they were peer-reviewed articles examining corticosteroids in PRES,excluding non-English publications,reviews,and editorials.Data on patient demographics,clinical characteristics,imaging findings,corticosteroid regimens,and outcomes were extracted.The risk of bias was evaluated using the Joanna Briggs Institute tool for case reports.RESULTS A total of 56 cases of PRES(66.1%women,33.9%men)potentially induced by corticosteroids and 14 cases in which corticosteroids were used to treat PRES were identified.Cases of PRES reportedly caused by corticosteroids showed a mean age of approximately 25.2 years,with seizures,headaches,hypertension,and visual disturbances being common clinical sequelae.Magnetic resonance findings typically revealed vasogenic edema in the bilateral parieto-occipital lobes.High-dose or prolonged corticosteroid therapy was a significant risk factor.On the contrary,in the treatment cases,corticosteroids were associated with positive outcomes,including resolution of vasogenic edema and stabilization of symptoms,particularly in patients with underlying inflammatory or autoimmune diseases.CONCLUSION Corticosteroids have a dual role in PRES,capable of both inducing and treating the condition.The current body of literature suggests that corticosteroids may play a greater role as a precipitating agent of PRES rather than treating.Corticosteroids may induce PRES through hypertension and subsequent increased cerebral blood flow and loss of autoregulation.Corticosteroids may aid in the management of PRES:(1)Enhancing endothelial stability;(2)Antiinflammatory properties;and(3)Improving blood-brain barrier integrity.Mechanisms which may reduce or mitigate vasogenic edema formation.展开更多
Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is cons...Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.展开更多
Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable e...Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable energy consumption.However,the practical application of RSOCs is still limited by the insufficient activity and stability of the electrodes in different operating modes.Herein,a highly efficient symmetrical electrode composed of La_(0.3)Sr_(0.6)Ti_(0.1)Co_(0.2)Fe_(0.7)O_(3-δ)(LSTCF)nanofibers and in situ exsolved Co_(3)Fe_(7) nanoparticles is developed for boosting the performance of RSOCs.The reversible phase transition,high activity and stability of the electrode have been confirmed by a combination of experimental(e.g.,transmission electron microscopy and X-ray absorption fine structure)and computational studies.Electrolyte-supported RSOCs with the symmetrical electrode demonstrate excellent catalytic activity and stability,achieving a high peak power density of 0.98 W cm^(-2)in the fuel cell mode using H_(2)as the fuel(or 0.53 W cm^(-2)using CH_(4)as the fuel)and a high current density of 1.09 A cm^(-2) at 1.4 V in the CO_(2)electrolysis mode(or 1.03 A cm^(-2)at 1.3 V for H_(2)O electrolysis)at 800℃while maintaining excellent durability for over 100 h.展开更多
Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible el...Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible elastic material with multicolor delayed fluorescence,which is constructed by 4-biphenylboronic acid(BOH),polyethylene glycol,2,2-bis(hydroxymethyl)propionic acid,isophorone diamine and isophorone diisocyanate copolymer.Importantly,the supramolecular phosphorescent elastomer not only exhibits extending RTP emission with a lifetime up to 1.21 s,but also gives a visible afterglow of 20 s via encapsulation of BOH unities by the deep cavities of hydroxypropyl-β-cyclodextrin(β-CD-HP)and in situ polymerization.Especially,after doping organic dyes(Fluorescein isothiocyanate,Sulforhodamine 101,Rhodamine B),supramolecular phosphorescent elastomer achieves multicolor delayed fluorescence realized by RTP energy transfer from phosphorescent donor to dye acceptors,which possesses reversible photo-thermal responsiveness and maintains high efficiency in delayed emission even after dozens of cycles.Present research provides a new approach for constructing multicolor delayed fluorescent supramolecular elastomers.展开更多
Lung ischemia-reperfusion injury(LIRI),an acute lung injury syndrome triggered by lung transplantation or distal organ ischemia,has long been a difficult and hot issue in clinical research.In this study,we proposed a ...Lung ischemia-reperfusion injury(LIRI),an acute lung injury syndrome triggered by lung transplantation or distal organ ischemia,has long been a difficult and hot issue in clinical research.In this study,we proposed a simple and less invasive reversible LIRI surgical protocol,achieved by improving the mouse left hilar entrapment model,which significantly improved the operability of the experiment and the reproducibility of the results.The protocol achieves precise control of the ischemic and reperfusion processes by visualizing transoral intubation,using reversible ligation of live knots to clamp the left hilar,and temporary closure of the thoracic cavity during ischemia.The reversible survival model we constructed not only provides a reliable tool to study the cellular and molecular mechanisms of LIRI but also can be used to assess the stage of injury regression,experimental pneumonia,and survival in mice.In addition,it simplifies the lung portal separation clamping operation for reversible clamping and provides an easy-to-learn visual tracheal intubation method that can be quickly mastered and replicated by beginners for consistent and reliable results.展开更多
With the rapid expansion of multimedia data,protecting digital information has become increasingly critical.Reversible data hiding offers an effective solution by allowing sensitive information to be embedded in multi...With the rapid expansion of multimedia data,protecting digital information has become increasingly critical.Reversible data hiding offers an effective solution by allowing sensitive information to be embedded in multimedia files while enabling full recovery of the original data after extraction.Audio,as a vital medium in communication,entertainment,and information sharing,demands the same level of security as images.However,embedding data in encrypted audio poses unique challenges due to the trade-offs between security,data integrity,and embedding capacity.This paper presents a novel interpolation-based reversible data hiding algorithm for encrypted audio that achieves scalable embedding capacity.By increasing sample density through interpolation,embedding opportunities are significantly enhanced while maintaining encryption throughout the process.The method further integrates multiple most significant bit(multi-MSB)prediction and Huffman coding to optimize compression and embedding efficiency.Experimental results on standard audio datasets demonstrate the proposed algorithm’s ability to embed up to 12.47 bits per sample with over 9.26 bits per sample available for pure embedding capacity,while preserving full reversibility.These results confirm the method’s suitability for secure applications that demand high embedding capacity and perfect reconstruction of original audio.This work advances reversible data hiding in encrypted audio by offering a secure,efficient,and fully reversible data hiding framework.展开更多
Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi...Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi-stego images provides good image quality but often results in low embedding capability.To address these challenges,this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image.The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order.Four secret bits are embedded into each block’s maximum pixel value,while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold.A similar embedding strategy is also applied to the minimum side of the block,including the second-smallest pixel value.This design enables each block to embed up to 14 bits of secret data.Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches,advancing the field of reversible steganography.展开更多
Medical image segmentation,i.e.,labeling structures of interest in medical images,is crucial for disease diagnosis and treatment in radiology.In reversible data hiding in medical images(RDHMI),segmentation consists of...Medical image segmentation,i.e.,labeling structures of interest in medical images,is crucial for disease diagnosis and treatment in radiology.In reversible data hiding in medical images(RDHMI),segmentation consists of only two regions:the focal and nonfocal regions.The focal region mainly contains information for diagnosis,while the nonfocal region serves as the monochrome background.The current traditional segmentation methods utilized in RDHMI are inaccurate for complex medical images,and manual segmentation is time-consuming,poorly reproducible,and operator-dependent.Implementing state-of-the-art deep learning(DL)models will facilitate key benefits,but the lack of domain-specific labels for existing medical datasets makes it impossible.To address this problem,this study provides labels of existing medical datasets based on a hybrid segmentation approach to facilitate the implementation of DL segmentation models in this domain.First,an initial segmentation based on a 33 kernel is performed to analyze×identified contour pixels before classifying pixels into focal and nonfocal regions.Then,several human expert raters evaluate and classify the generated labels into accurate and inaccurate labels.The inaccurate labels undergo manual segmentation by medical practitioners and are scored based on a hierarchical voting scheme before being assigned to the proposed dataset.To ensure reliability and integrity in the proposed dataset,we evaluate the accurate automated labels with manually segmented labels by medical practitioners using five assessment metrics:dice coefficient,Jaccard index,precision,recall,and accuracy.The experimental results show labels in the proposed dataset are consistent with the subjective judgment of human experts,with an average accuracy score of 94%and dice coefficient scores between 90%-99%.The study further proposes a ResNet-UNet with concatenated spatial and channel squeeze and excitation(scSE)architecture for semantic segmentation to validate and illustrate the usefulness of the proposed dataset.The results demonstrate the superior performance of the proposed architecture in accurately separating the focal and nonfocal regions compared to state-of-the-art architectures.Dataset information is released under the following URL:https://www.kaggle.com/lordamoah/datasets(accessed on 31 March 2025).展开更多
High entropy alloys(HEAs)have attracted much attention for their excellent mechanical properties stem-ming from diverse deformation mechanisms.Particularly,face-centered cubic(FCC)to body-centered cu-bic(BCC)martensit...High entropy alloys(HEAs)have attracted much attention for their excellent mechanical properties stem-ming from diverse deformation mechanisms.Particularly,face-centered cubic(FCC)to body-centered cu-bic(BCC)martensitic transformation is crucial for enhancing the strength and plasticity of HEAs,partic-ularly at cryogenic temperatures.However,the fundamental atomic mechanism underlying martensitic transformation remains elusive,and the impact of martensitic transformation on the mechanical prop-erties of HEAs at room temperature is unknown.Here,we report in situ atomic-scale observation of a reversible martensitic transformation from FCC to body-centered tetragonal(BCT)and ultimately back to FCC in the nanostructured CrMnFeCoNi HEA at room temperature under deformation.This martensitic transformation is completed by the synergistic action of 90°partial dislocations slip on(111)FCC plane and atom shuffling,involving the periodic arrangement and slip of two 90°half Shockley partial disloca-tions a/12[112](111)and one 90°Shockley partial dislocation-a/6[112](111)on three successive(111)FCC atomic planes.Additionally,the reversible phase transformation induced by high stress dissipates strain energies and hinders crack propagation,thereby enhancing the fracture toughness of HEAs.Our findings contribute to a deeper comprehension of the martensitic transformation mechanisms in HEAs,offering valuable insights for improving their mechanical properties.展开更多
The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different in...The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different inlets on the upper and lower surfaces is proposed to adapt to widerange flight.Firstly,the double-sided intake configuration’s design method and flight profile are delineated.Secondly,Computational Fluid Dynamics(CFD)numerical simulation based on multi-Graphics Processing Unit(GPU)parallel computing is adopted to evaluate the vehicle’s performance comprehensively,aiming to verify the feasibility of the proposed scheme.This evaluation encompasses a wide-range basic aerodynamic characteristics,inlet performance,and heat flux at critical locations.The results show that the inlets of the designed integration configuration can start up across Mach number 3.5 to 8.The vehicle possesses multi-point cruising capability by flipping the fuselage.Simultaneously,a 180°rotation of the fuselage can significantly decrease the heat accumulation on the lower surface of the vehicle,particularly at the inlet lip,further decreasing the temperature gradient across the vehicle structure.This study has some engineering value for the aerodynamic configuration design of wide-range vehicles.However,further study reveals that the flow phenomena at the intersection of two inlets are complex,posing potential adverse impacts on propulsion efficiency.Therefore,it is imperative to conduct additional research to delve into this matter comprehensively.展开更多
The insufficient stability and poor surface reaction kinetics(i.e.,oxygen reduction reaction(ORR)and oxygen evolution reaction(OER))of air electrodes are significant factors hindering the development of reversible sol...The insufficient stability and poor surface reaction kinetics(i.e.,oxygen reduction reaction(ORR)and oxygen evolution reaction(OER))of air electrodes are significant factors hindering the development of reversible solid oxide cells(R-SOCs).The high-entropy strategy offers a new direction to optimize air electrodes.We introduce a high-entropy air electrode,(La_(0.12)Pr_(0.12)Nd_(0.12)Sm_(0.12)Gd_(0.12))Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LPNSGSrCF),demonstrating a low polarization resistance(0.15Ωcm^(2))and good durability(1.3×10^(-3)Ωcm^(2)h^(-1)),superior to those of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(0.31Ωcm^(2),2.0×10^(-3)Ωcm^(2)h^(-1))at 650℃.The elevated activity may be a result of the substantial concentration of oxygen vacancies and rapid reaction kinetics,as verified by X-ray photoelectron spectroscopy,electrochemical impedance spectroscopy,and distribution of relaxation times studies.Specifically,an R-SOC with LPNSGSrCF air electrode achieves a peak power density of 1.05 W cm^(-2)in fuel cell mode and a current density of0.89 A cm^(-2)at 1.3 V in electrolysis cell mode(with 30%H_(2)O)at 700℃.Moreover,the cells with LPNSGSrCF electrode can be stably operated in both modes for over 100 h.展开更多
The slow oxygen reaction kinetics of air electrodes impair the performance of reversible protonic ceramic electrochemical cells(R-PCECs);hence,it is imperative to design novel air electrodes featuring excellent cataly...The slow oxygen reaction kinetics of air electrodes impair the performance of reversible protonic ceramic electrochemical cells(R-PCECs);hence,it is imperative to design novel air electrodes featuring excellent catalytic activity and endurance.Here,we report an Rb-doped double perovskite PrBa_(0.8)Ca_(0.1)Rb_(0.1)Co_(2)O_(5+δ)(denoted as PBCR_(0.1)C)as an air electrode for R-PCECs,displaying a low polarization resistance of 0.044Ωcm^(2) at 700℃ and excellent stability during exposure to humid air(3 vol%H_(2)O).The high performance is attributed to the high electrical conductivity,high concentration of oxygen vacancies,and fast surface exchange,as verified by the analyses of X-ray photoelectron spectroscopy,thermogravimetric testing,and conductivity tests.The R-PCECs with the PBCR_(0.1)C air electrode demonstrate an encouraging performance at 700℃:a peak power density of 2.32 W cm^(-2) in a fuel cell(FC)mode and an electrolysis current density of-3.55 A cm^(-2) at 1.3 V in an electrolysis(EL)mode.At 30 vol%steam concentration,a Faraday efficiency of 87.80%and a corresponding H_(2) production rate of 3.05 mL min^(-1) cm^(-2) at a current density of-0.5 A cm^(-2) at 650℃.Additionally,the durability of the cell in the FC mode(120 h),EL mode(120 h),and cycling FC/EL mode(100 h)at 650℃ suggests the great potential of PBCR_(0.1)C as the highly reactive and robust air electrodes of R-PCECs.展开更多
Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the ...Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn^(2+)-solvation and deposition behavior demand comprehensive investigation.Organic molecules endowed with special functional groups (such as hydroxyl,carboxyl,etc.) have the potential to significantly optimize the solvation structure of Zn^(2+)and regulate the interfacial electric double layer (EDL).By increasing nucleation overpotential and decreasing interfacial free energy,these functional groups facilitate a lower critical nucleation radius,thereby forming an asymptotic nucleation model to promote uniform Zn deposition.Herein,this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure.The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques,indicating that the H-Zn anode exhibits dendrite-free growth,no by-products,and weak hydrogen evolution,in sharp contrast to the bare Zn.Consequently,the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h.Moreover,the H-Zn//NH_(4)V_(4)O^(10)(NVO) full battery showcases exceptional cycle stability,retaining 95.04%capacity retention after 400 cycles at a large current density of 5 A g^(-1).This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.展开更多
Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this e...Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this end,in vitro platforms are needed to test therapies directed at salivary(fluid-secreting)cells.However,since these are highly differentiated secretory cells,the maintenance of their differentiated state while expanding in numbers is challenging.In this study,the efficiency of three reversible thermo-ionically crosslinked gels:(1)alginate–gelatin(AG),(2)collagen-containing AG(AGC),and(3)hyaluronic acid-containing AG(AGHA),to recapitulate a native-like environment for human salivary gland(SG)cell expansion and 3D spheroid formation was compared.Although all gels were of mechanical properties comparable to human SG tissue(~11 kPa)and promoted the formation of 3D spheroids,AGHA gels produced larger(>100 cells/spheroid),viable(>93%),proliferative,and well-organized 3D SG spheroids while spatially and temporally maintaining the high expression of key SG proteins(aquaporin-5,NKCC1,ZO-1,α-amylase)for 14 days in culture.Moreover,the spheroids responded to agonist-induced stimulation by increasingα-amylase secretory granules.Here,we propose alternative lowcost,reproducible,and reversible AG-based 3D hydrogels that allow the facile and rapid retrieval of intact,highly viable 3D-SG spheroids.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.
基金financially supported by the National Natural Science Foundation of China(Nos.22379030,52001079,52261038)the Science and Technology Department of Guangxi Zhuang Autonomous(Nos.2024JJG160001,GuiKeAD21238022)the Innovation Project of Guangxi Graduate Education(No.YCBZ2023011)
文摘As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).
基金support provided by the National Key R&D Program of China(No.2024YFE0101500)the National Natural Science Foundation of China(No.52272257)the Natural Science Foundation of Jiangsu Province(No.BK20240109).
文摘Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.
基金financially supported by the Sichuan Science and Technology Program(2022YFS0025 and 2024YFFK0133)supported by the“Fundamental Research Funds for the Central Universities of China.”。
文摘Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.
文摘Pseudoephedrine (PSE) is a widely used nasal decongestant. A review by the European Medicines Agency has reported that PSE may be associated with risks of posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS). PRES and RCVS are rare but serious conditions that affect cerebral blood flow. This review discusses the pharmacology of PSE and potential risks for PRES and RCVS and concludes that considering the common use of PSE, with over 70 million packs of PSE taken each year in the European Union and the United Kingdom, and the rare occurrence of PRES and RCVS, that the risks of developing PRES/RCVS on exposure to PSE are likely to be very low.
文摘This paper, an addendum to “Dialectical Thermodynamics’ solution to the conceptual imbroglio that is the reversible path”, this journal, 10, 775-799, was written in response to the requests of several readers to provide further evidence of the said “imbroglio”. The evidence here presented relates to the incompatibility existing between the total-entropy and the Gibbs energy prescriptions for the reversible path. The previously published proof of the negentropic nature of the transformation of heat into work is here included to validate out conclusions about the Gibbs energy perspective.
文摘BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involves endothelial dysfunction,disrupted cerebral autoregulation,and resulting vasogenic edema.Hypertension and other factors that alter cerebral autoregulation are critical in its development.Corticosteroids,widely used for their anti-inflammatory and immunosuppressive properties,play a controversial role in PRES.AIM To elucidate the dual role of corticosteroids in the context of PRES by critically evaluating the existing literature.Specifically,it seeks to assess the results of PRES induced by corticosteroid therapy and the efficacy and safety of corticosteroids in the treatment of PRES.By synthesizing case reports and series,this review aims to provide a comprehensive understanding of the mechanisms,clinical presentations,and management strategies associated with corticosteroid-related PRES.METHODS The review was carried out according to the PRISMA guidelines.The databases searched included Science Direct,PubMed,and Hinari.The search strategy encompassed terms related to corticosteroids and PRES.Studies were included if they were peer-reviewed articles examining corticosteroids in PRES,excluding non-English publications,reviews,and editorials.Data on patient demographics,clinical characteristics,imaging findings,corticosteroid regimens,and outcomes were extracted.The risk of bias was evaluated using the Joanna Briggs Institute tool for case reports.RESULTS A total of 56 cases of PRES(66.1%women,33.9%men)potentially induced by corticosteroids and 14 cases in which corticosteroids were used to treat PRES were identified.Cases of PRES reportedly caused by corticosteroids showed a mean age of approximately 25.2 years,with seizures,headaches,hypertension,and visual disturbances being common clinical sequelae.Magnetic resonance findings typically revealed vasogenic edema in the bilateral parieto-occipital lobes.High-dose or prolonged corticosteroid therapy was a significant risk factor.On the contrary,in the treatment cases,corticosteroids were associated with positive outcomes,including resolution of vasogenic edema and stabilization of symptoms,particularly in patients with underlying inflammatory or autoimmune diseases.CONCLUSION Corticosteroids have a dual role in PRES,capable of both inducing and treating the condition.The current body of literature suggests that corticosteroids may play a greater role as a precipitating agent of PRES rather than treating.Corticosteroids may induce PRES through hypertension and subsequent increased cerebral blood flow and loss of autoregulation.Corticosteroids may aid in the management of PRES:(1)Enhancing endothelial stability;(2)Antiinflammatory properties;and(3)Improving blood-brain barrier integrity.Mechanisms which may reduce or mitigate vasogenic edema formation.
文摘Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.
基金supported by the National Natural Science Foundation of China(No.52377212 and 51877173)program of Beijing Huairou Laboratory(ZD2022006A)+2 种基金the Key R&D Project of Shaanxi Province(2023-YBGY-057)the State Key Laboratory of Electrical Insulation and Power Equipment(EIPE22314,EIPE22306)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-QN-0483).
文摘Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable energy consumption.However,the practical application of RSOCs is still limited by the insufficient activity and stability of the electrodes in different operating modes.Herein,a highly efficient symmetrical electrode composed of La_(0.3)Sr_(0.6)Ti_(0.1)Co_(0.2)Fe_(0.7)O_(3-δ)(LSTCF)nanofibers and in situ exsolved Co_(3)Fe_(7) nanoparticles is developed for boosting the performance of RSOCs.The reversible phase transition,high activity and stability of the electrode have been confirmed by a combination of experimental(e.g.,transmission electron microscopy and X-ray absorption fine structure)and computational studies.Electrolyte-supported RSOCs with the symmetrical electrode demonstrate excellent catalytic activity and stability,achieving a high peak power density of 0.98 W cm^(-2)in the fuel cell mode using H_(2)as the fuel(or 0.53 W cm^(-2)using CH_(4)as the fuel)and a high current density of 1.09 A cm^(-2) at 1.4 V in the CO_(2)electrolysis mode(or 1.03 A cm^(-2)at 1.3 V for H_(2)O electrolysis)at 800℃while maintaining excellent durability for over 100 h.
基金financially supported by the National Natural Science Foundation of China(No.22131008)。
文摘Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible elastic material with multicolor delayed fluorescence,which is constructed by 4-biphenylboronic acid(BOH),polyethylene glycol,2,2-bis(hydroxymethyl)propionic acid,isophorone diamine and isophorone diisocyanate copolymer.Importantly,the supramolecular phosphorescent elastomer not only exhibits extending RTP emission with a lifetime up to 1.21 s,but also gives a visible afterglow of 20 s via encapsulation of BOH unities by the deep cavities of hydroxypropyl-β-cyclodextrin(β-CD-HP)and in situ polymerization.Especially,after doping organic dyes(Fluorescein isothiocyanate,Sulforhodamine 101,Rhodamine B),supramolecular phosphorescent elastomer achieves multicolor delayed fluorescence realized by RTP energy transfer from phosphorescent donor to dye acceptors,which possesses reversible photo-thermal responsiveness and maintains high efficiency in delayed emission even after dozens of cycles.Present research provides a new approach for constructing multicolor delayed fluorescent supramolecular elastomers.
基金Natural Science Foundation of Anhui ProvinceGrant/Award Number:1908085MH241。
文摘Lung ischemia-reperfusion injury(LIRI),an acute lung injury syndrome triggered by lung transplantation or distal organ ischemia,has long been a difficult and hot issue in clinical research.In this study,we proposed a simple and less invasive reversible LIRI surgical protocol,achieved by improving the mouse left hilar entrapment model,which significantly improved the operability of the experiment and the reproducibility of the results.The protocol achieves precise control of the ischemic and reperfusion processes by visualizing transoral intubation,using reversible ligation of live knots to clamp the left hilar,and temporary closure of the thoracic cavity during ischemia.The reversible survival model we constructed not only provides a reliable tool to study the cellular and molecular mechanisms of LIRI but also can be used to assess the stage of injury regression,experimental pneumonia,and survival in mice.In addition,it simplifies the lung portal separation clamping operation for reversible clamping and provides an easy-to-learn visual tracheal intubation method that can be quickly mastered and replicated by beginners for consistent and reliable results.
基金funded by theNational Science and Technology Council of Taiwan under the grant number NSTC 113-2221-E-035-058.
文摘With the rapid expansion of multimedia data,protecting digital information has become increasingly critical.Reversible data hiding offers an effective solution by allowing sensitive information to be embedded in multimedia files while enabling full recovery of the original data after extraction.Audio,as a vital medium in communication,entertainment,and information sharing,demands the same level of security as images.However,embedding data in encrypted audio poses unique challenges due to the trade-offs between security,data integrity,and embedding capacity.This paper presents a novel interpolation-based reversible data hiding algorithm for encrypted audio that achieves scalable embedding capacity.By increasing sample density through interpolation,embedding opportunities are significantly enhanced while maintaining encryption throughout the process.The method further integrates multiple most significant bit(multi-MSB)prediction and Huffman coding to optimize compression and embedding efficiency.Experimental results on standard audio datasets demonstrate the proposed algorithm’s ability to embed up to 12.47 bits per sample with over 9.26 bits per sample available for pure embedding capacity,while preserving full reversibility.These results confirm the method’s suitability for secure applications that demand high embedding capacity and perfect reconstruction of original audio.This work advances reversible data hiding in encrypted audio by offering a secure,efficient,and fully reversible data hiding framework.
基金funded by University of Transport and Communications(UTC)under grant number T2025-CN-004.
文摘Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi-stego images provides good image quality but often results in low embedding capability.To address these challenges,this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image.The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order.Four secret bits are embedded into each block’s maximum pixel value,while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold.A similar embedding strategy is also applied to the minimum side of the block,including the second-smallest pixel value.This design enables each block to embed up to 14 bits of secret data.Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches,advancing the field of reversible steganography.
基金supported by the National Natural Science Foundation of China(Grant Nos.62072250,61772281,61702235,U1636117,U1804263,62172435,61872203 and 61802212)the Zhongyuan Science and Technology Innovation Leading Talent Project of China(Grant No.214200510019)+3 种基金the Suqian Municipal Science and Technology Plan Project in 2020(S202015)the Plan for Scientific Talent of Henan Province(Grant No.2018JR0018)the Opening Project of Guangdong Provincial Key Laboratory of Information Security Technology(Grant No.2020B1212060078)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Fund.
文摘Medical image segmentation,i.e.,labeling structures of interest in medical images,is crucial for disease diagnosis and treatment in radiology.In reversible data hiding in medical images(RDHMI),segmentation consists of only two regions:the focal and nonfocal regions.The focal region mainly contains information for diagnosis,while the nonfocal region serves as the monochrome background.The current traditional segmentation methods utilized in RDHMI are inaccurate for complex medical images,and manual segmentation is time-consuming,poorly reproducible,and operator-dependent.Implementing state-of-the-art deep learning(DL)models will facilitate key benefits,but the lack of domain-specific labels for existing medical datasets makes it impossible.To address this problem,this study provides labels of existing medical datasets based on a hybrid segmentation approach to facilitate the implementation of DL segmentation models in this domain.First,an initial segmentation based on a 33 kernel is performed to analyze×identified contour pixels before classifying pixels into focal and nonfocal regions.Then,several human expert raters evaluate and classify the generated labels into accurate and inaccurate labels.The inaccurate labels undergo manual segmentation by medical practitioners and are scored based on a hierarchical voting scheme before being assigned to the proposed dataset.To ensure reliability and integrity in the proposed dataset,we evaluate the accurate automated labels with manually segmented labels by medical practitioners using five assessment metrics:dice coefficient,Jaccard index,precision,recall,and accuracy.The experimental results show labels in the proposed dataset are consistent with the subjective judgment of human experts,with an average accuracy score of 94%and dice coefficient scores between 90%-99%.The study further proposes a ResNet-UNet with concatenated spatial and channel squeeze and excitation(scSE)architecture for semantic segmentation to validate and illustrate the usefulness of the proposed dataset.The results demonstrate the superior performance of the proposed architecture in accurately separating the focal and nonfocal regions compared to state-of-the-art architectures.Dataset information is released under the following URL:https://www.kaggle.com/lordamoah/datasets(accessed on 31 March 2025).
基金the Natural Science Foundation of China(Nos.52173224,52130105)the Natural Science Foundation of Shanghai(No.21ZR1431200)+2 种基金Shanghai Jiao Tong University-JA Solar New Energy Materials Joint Research Center.Shufen Chu is supported by the China Postdoctoral Science Foundation(No.2023M742218)Fan Zhang is supported by the National Key Lab-oratory Foundation of Science and Technology on Materials under Shock and Impact(No.WDZC2022-1)the National Natural Sci-ence Foundation of China((No.52271141).
文摘High entropy alloys(HEAs)have attracted much attention for their excellent mechanical properties stem-ming from diverse deformation mechanisms.Particularly,face-centered cubic(FCC)to body-centered cu-bic(BCC)martensitic transformation is crucial for enhancing the strength and plasticity of HEAs,partic-ularly at cryogenic temperatures.However,the fundamental atomic mechanism underlying martensitic transformation remains elusive,and the impact of martensitic transformation on the mechanical prop-erties of HEAs at room temperature is unknown.Here,we report in situ atomic-scale observation of a reversible martensitic transformation from FCC to body-centered tetragonal(BCT)and ultimately back to FCC in the nanostructured CrMnFeCoNi HEA at room temperature under deformation.This martensitic transformation is completed by the synergistic action of 90°partial dislocations slip on(111)FCC plane and atom shuffling,involving the periodic arrangement and slip of two 90°half Shockley partial disloca-tions a/12[112](111)and one 90°Shockley partial dislocation-a/6[112](111)on three successive(111)FCC atomic planes.Additionally,the reversible phase transformation induced by high stress dissipates strain energies and hinders crack propagation,thereby enhancing the fracture toughness of HEAs.Our findings contribute to a deeper comprehension of the martensitic transformation mechanisms in HEAs,offering valuable insights for improving their mechanical properties.
基金co-supported by the Foundation of National Key Laboratory of Science and Technology on Aerodynamic Design and Research,China(No.614220121020114)the Key R&D Projects of Hunan Province,China(No.2023GK2022)。
文摘The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different inlets on the upper and lower surfaces is proposed to adapt to widerange flight.Firstly,the double-sided intake configuration’s design method and flight profile are delineated.Secondly,Computational Fluid Dynamics(CFD)numerical simulation based on multi-Graphics Processing Unit(GPU)parallel computing is adopted to evaluate the vehicle’s performance comprehensively,aiming to verify the feasibility of the proposed scheme.This evaluation encompasses a wide-range basic aerodynamic characteristics,inlet performance,and heat flux at critical locations.The results show that the inlets of the designed integration configuration can start up across Mach number 3.5 to 8.The vehicle possesses multi-point cruising capability by flipping the fuselage.Simultaneously,a 180°rotation of the fuselage can significantly decrease the heat accumulation on the lower surface of the vehicle,particularly at the inlet lip,further decreasing the temperature gradient across the vehicle structure.This study has some engineering value for the aerodynamic configuration design of wide-range vehicles.However,further study reveals that the flow phenomena at the intersection of two inlets are complex,posing potential adverse impacts on propulsion efficiency.Therefore,it is imperative to conduct additional research to delve into this matter comprehensively.
基金supported by the National Key R&D Program of China(2022YFB4003601)the National Natural Science Foundation of China(22179039)+4 种基金the Introduced Innovative R&D Team of Guangdong(2021ZT09L392)the Guangzhou Science and Technology Project(2024A04J3079)the Guangdong Basic and Applied Basic Research Foundation(2024A1515010448)the Pearl River Talent Recruitment Program(2019QN01C693)Zijin Mining Group Co.,Ltd(5405-ZC-2023-00008).
文摘The insufficient stability and poor surface reaction kinetics(i.e.,oxygen reduction reaction(ORR)and oxygen evolution reaction(OER))of air electrodes are significant factors hindering the development of reversible solid oxide cells(R-SOCs).The high-entropy strategy offers a new direction to optimize air electrodes.We introduce a high-entropy air electrode,(La_(0.12)Pr_(0.12)Nd_(0.12)Sm_(0.12)Gd_(0.12))Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LPNSGSrCF),demonstrating a low polarization resistance(0.15Ωcm^(2))and good durability(1.3×10^(-3)Ωcm^(2)h^(-1)),superior to those of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(0.31Ωcm^(2),2.0×10^(-3)Ωcm^(2)h^(-1))at 650℃.The elevated activity may be a result of the substantial concentration of oxygen vacancies and rapid reaction kinetics,as verified by X-ray photoelectron spectroscopy,electrochemical impedance spectroscopy,and distribution of relaxation times studies.Specifically,an R-SOC with LPNSGSrCF air electrode achieves a peak power density of 1.05 W cm^(-2)in fuel cell mode and a current density of0.89 A cm^(-2)at 1.3 V in electrolysis cell mode(with 30%H_(2)O)at 700℃.Moreover,the cells with LPNSGSrCF electrode can be stably operated in both modes for over 100 h.
文摘The slow oxygen reaction kinetics of air electrodes impair the performance of reversible protonic ceramic electrochemical cells(R-PCECs);hence,it is imperative to design novel air electrodes featuring excellent catalytic activity and endurance.Here,we report an Rb-doped double perovskite PrBa_(0.8)Ca_(0.1)Rb_(0.1)Co_(2)O_(5+δ)(denoted as PBCR_(0.1)C)as an air electrode for R-PCECs,displaying a low polarization resistance of 0.044Ωcm^(2) at 700℃ and excellent stability during exposure to humid air(3 vol%H_(2)O).The high performance is attributed to the high electrical conductivity,high concentration of oxygen vacancies,and fast surface exchange,as verified by the analyses of X-ray photoelectron spectroscopy,thermogravimetric testing,and conductivity tests.The R-PCECs with the PBCR_(0.1)C air electrode demonstrate an encouraging performance at 700℃:a peak power density of 2.32 W cm^(-2) in a fuel cell(FC)mode and an electrolysis current density of-3.55 A cm^(-2) at 1.3 V in an electrolysis(EL)mode.At 30 vol%steam concentration,a Faraday efficiency of 87.80%and a corresponding H_(2) production rate of 3.05 mL min^(-1) cm^(-2) at a current density of-0.5 A cm^(-2) at 650℃.Additionally,the durability of the cell in the FC mode(120 h),EL mode(120 h),and cycling FC/EL mode(100 h)at 650℃ suggests the great potential of PBCR_(0.1)C as the highly reactive and robust air electrodes of R-PCECs.
基金National Natural Science Foundation of China (52301273, 52072411)Science and Technology Innovation Program of Hunan Province (2024RC3222)+3 种基金Key project of scientific research project of Hunan Provincial Department of Education (22A0479)China Postdoctoral Science Foundation (2024M753668)Central South University Innovation-Driven Research Programme (2023CXQD038)Hunan Provincial Postgraduate Research Innovation Programme(CX20240970)。
文摘Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn^(2+)-solvation and deposition behavior demand comprehensive investigation.Organic molecules endowed with special functional groups (such as hydroxyl,carboxyl,etc.) have the potential to significantly optimize the solvation structure of Zn^(2+)and regulate the interfacial electric double layer (EDL).By increasing nucleation overpotential and decreasing interfacial free energy,these functional groups facilitate a lower critical nucleation radius,thereby forming an asymptotic nucleation model to promote uniform Zn deposition.Herein,this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure.The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques,indicating that the H-Zn anode exhibits dendrite-free growth,no by-products,and weak hydrogen evolution,in sharp contrast to the bare Zn.Consequently,the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h.Moreover,the H-Zn//NH_(4)V_(4)O^(10)(NVO) full battery showcases exceptional cycle stability,retaining 95.04%capacity retention after 400 cycles at a large current density of 5 A g^(-1).This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.
基金support from Fonds de Recherche du Québec Santé(FRQS,grant no.281271)support from FRQS doctoral award #304367funding from CFI,Rheolution Inc.,and Investissement Québec.
文摘Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this end,in vitro platforms are needed to test therapies directed at salivary(fluid-secreting)cells.However,since these are highly differentiated secretory cells,the maintenance of their differentiated state while expanding in numbers is challenging.In this study,the efficiency of three reversible thermo-ionically crosslinked gels:(1)alginate–gelatin(AG),(2)collagen-containing AG(AGC),and(3)hyaluronic acid-containing AG(AGHA),to recapitulate a native-like environment for human salivary gland(SG)cell expansion and 3D spheroid formation was compared.Although all gels were of mechanical properties comparable to human SG tissue(~11 kPa)and promoted the formation of 3D spheroids,AGHA gels produced larger(>100 cells/spheroid),viable(>93%),proliferative,and well-organized 3D SG spheroids while spatially and temporally maintaining the high expression of key SG proteins(aquaporin-5,NKCC1,ZO-1,α-amylase)for 14 days in culture.Moreover,the spheroids responded to agonist-induced stimulation by increasingα-amylase secretory granules.Here,we propose alternative lowcost,reproducible,and reversible AG-based 3D hydrogels that allow the facile and rapid retrieval of intact,highly viable 3D-SG spheroids.
