Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome t...Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome the limitations of single ironbased oxygen carriers,including poor cycling stability,low reactivity and susceptibility to sintering,this study employed a dipcoating method to modify Fe_(2)O_(3)/Al_(2)O_(3)oxygen carriers by incorporating three distinct metal additives:Cu,La and Ce.The composite oxygen carriers were systematically characterized and evaluated under redox conditions to investigate the structure-activity relationships between the physicochemical properties,reactivity,and hydrogen production performance.Results revealed that the spinel-phase CuFe_(2)O_(4)exhibited higher reactivity than the perovskite-phase LaFeO_(3)and CeO_(2),promoting the deeper reduction of Fe_(2)O_(3).Fe58Cu2Al exhibited an oxygen storage capacity as high as 6.5 mmol/g.During the CH4 reaction stage,Fe58Cu2Al achieved the highest oxygen loss of 12.1 g/100 g oxygen carrier,accompanied by a syngas yield of 5.15 mmol/g-1.33 times and 1.59 times greater than that of Fe60Al.In the hydrogen production stage,the 2%Cu-modified oxygen carrier demonstrated optimal performance,yielding 5.13 mmol/g of hydrogen,which was 1.51 times that of the pristine sample.Even after ten cycles,the H_(2)yield remained at 3.61 mmol/g,surpassing the single-cycle output of the pristine sample and the H2 purity consistently exceeded 98%.展开更多
Delivery carriers serve as a highly efficient approach for precision nutrition and medicine;however,artificial delivery carriers are prone to triggering the immune response and have the disadvantages of poor stability...Delivery carriers serve as a highly efficient approach for precision nutrition and medicine;however,artificial delivery carriers are prone to triggering the immune response and have the disadvantages of poor stability and low bioavailability.Extracellular vesicles(EVs),nucleus-free biological particles composed of phospholipid bilayers secreted by living cells,are a new generation of targeted delivery carriers.In recent years,an increasing number of species have been reported to contain EVs.Among them,food-derived extracellular vesicles(FDEVs)show outstanding comprehensive properties.FDEVs are considered to have great application potential due to their wide range of sources,high yields,absence of human pathogenic pathogens,and ethical concerns.In this review,the preparation,nomenclature,physicochemical characteristics,and preservation methods of FDEVs are discussed,as well as their potential protein markers,bioactivities,and applications as novel targeted delivery carriers of FDEVs from animals,plants,and microorganisms.We also summarized the adverse consequences of FDEVs in current studies,and put forward the problems and challenges in the process of FDEVs research and commercialization.In short,the importance of FDEVs has been highlighted,and FDEVs have good application prospects as a new class of targeted delivery carriers.The current problems should be paid attention to and actively solved.展开更多
The radio frequency(RF)fingerprint technique is a robust method for security enhancement of the physical layer by leveraging the unique RF imperfections inherent in various wireless devices.Among these imperfections,t...The radio frequency(RF)fingerprint technique is a robust method for security enhancement of the physical layer by leveraging the unique RF imperfections inherent in various wireless devices.Among these imperfections,the carrier frequency offset(CFO)stands out as a primary RF fingerprint(RFF)of the transmitter,offering the potential to distinguish among different transmitters.However,accurately estimating CFO in time-varying channels poses significant challenges due to multipath effects and Doppler shifts.In this paper,we focus on estimating CFO for wireless device identification in the orthogonal frequency division multiplexing(OFDM)communication system.To achieve precise CFO estimation under time-varying channels,we propose a frequency domain correlation and spline interpolation(FCSI)algorithm.This approach utilizes pilots distributed across different subcarriers to correlate with prior local sequences,facilitating accurate CFO estimation.Classification is then performed based on the Euclidean distance between the prior RFF and the tested RFF dataset.Simulation results demonstrate that the proposed Mconsecutive average method effectively reduces the classification error rate in the challenging high-frequency(HF)skywave channel environment.展开更多
The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a coll...The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a collaborative scheduling problem inherent to the operational processes of carrier aircraft,where launch and recovery tasks are conducted concurrently on the flight deck.The objective is to minimize the cumulative weighted waiting time in the air for recovering aircraft and the cumulative weighted delay time for launching aircraft.To tackle this challenge,a multiple population self-adaptive differential evolution(MPSADE)algorithm is proposed.This method features a self-adaptive parameter updating mechanism that is contingent upon population diversity,an asynchronous updating scheme,an individual migration operator,and a global crossover mechanism.Additionally,comprehensive experiments are conducted to validate the effectiveness of the proposed model and algorithm.Ultimately,a comparative analysis with existing operation modes confirms the enhanced efficiency of the collaborative operation mode.展开更多
Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.Th...Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.The published version showed“Hongzhen Chen”,whereas the correct spelling should be“Hongzheng Chen”.The correct author name has been provided in this Correction,and the original article[1]has been corrected.展开更多
Band inversion induced by spin–orbit coupling in topological semimetals typically generates light charge carriers with high Fermi velocities,which are highly desirable for low-dissipation and coherent quantum transpo...Band inversion induced by spin–orbit coupling in topological semimetals typically generates light charge carriers with high Fermi velocities,which are highly desirable for low-dissipation and coherent quantum transport in topological devices.The presence of these carriers in real materials strongly depends on the Fermi-level position.2M-WSe_(2),with its topological and van der Waals nature,serves as an ideal platform for studying quantum transport in two-dimensional systems,despite the fact that interlayer coupling suppresses the formation of light carriers.In this study,we solvothermally intercalate 1,3-diaminopropane molecules into the interlayer space of 2M-WSe_(2);these molecules effectively adapt to the electronic structure by eliminating interlayer coupling.Simultaneously,slight electron doping via charge transfer results in a small Fermi pocket with an extremely light effective mass,0.04–0.06 me,as revealed by quantum oscillation measurements.This study demonstrates that molecular intercalation is an effective approach for engineering van der Waals topological materials to achieve specific quantum transport properties.展开更多
Safe and efficient sortie scheduling on the confined flight deck is crucial for maintaining high combat effectiveness of the aircraft carrier.The primary difficulty exactly lies in the spatiotemporal coordination,i.e....Safe and efficient sortie scheduling on the confined flight deck is crucial for maintaining high combat effectiveness of the aircraft carrier.The primary difficulty exactly lies in the spatiotemporal coordination,i.e.,allocation of limited supporting resources and collision-avoidance between heterogeneous dispatch entities.In this paper,the problem is investigated in the perspective of hybrid flow-shop scheduling problem by synthesizing the precedence,space and resource constraints.Specifically,eight processing procedures are abstracted,where tractors,preparing spots,catapults,and launching are virtualized as machines.By analyzing the constraints in sortie scheduling,a mixed-integer planning model is constructed.In particular,the constraint on preparing spot occupancy is improved to further enhance the sortie efficiency.The basic trajectory library for each dispatch entity is generated and a delayed strategy is integrated to address the collision-avoidance issue.To efficiently solve the formulated HFSP,which is essentially a combinatorial problem with tightly coupled constraints,a chaos-initialized genetic algorithm is developed.The solution framework is validated by the simulation environment referring to the Fort-class carrier,exhibiting higher sortie efficiency when compared to existing strategies.And animation of the simulation results is available at www.bilibili.com/video/BV14t421A7Tt/.The study presents a promising supporting technique for autonomous flight deck operation in the foreseeable future,and can be easily extended to other supporting scenarios,e.g.,ammunition delivery and aircraft maintenance.展开更多
Despite significant advancements in the power conversion efficiency(PCE)of perovskite/silicon tandem solar cells,improving carrier management in top cells remains challenging due to the defective dual interfaces of wi...Despite significant advancements in the power conversion efficiency(PCE)of perovskite/silicon tandem solar cells,improving carrier management in top cells remains challenging due to the defective dual interfaces of wide-bandgap perovskite,particularly on textured silicon surfaces.Herein,a series of halide ions(Cl^(-),Br^(-),I^(-))substituted piperazinium salts are designed and synthesized as post-treatment modifiers for perovskite surfaces.Notably,piperazinium chloride induces an asymmetric bidirectional ions distribution from the top to the bottom surface,with large piperazinium cations concentrating at the perovskite surface and small chloride anions migrating downward to accumulate at the buried interface.This results in effective dual-interface defect passivation and energy band modulation,enabling wide-bandgap(1.68 eV)perovskite solar cells to achieve a PCE of 22.3%and a record product of open-circuit voltage×fill factor(84.4%relative to the Shockley-Queisser limit).Furthermore,the device retains 91.3%of its initial efficiency after 1200 h of maximum power point tracking without encapsulation.When integrated with double-textured silicon heterojunction solar cells,a remarkable PCE of 31.5%is achieved for a 1.04 cm^(2) monolithic perovskite/silicon tandem solar cell,exhibiting excellent long-term operational stability(T_(80)=755 h)without encapsulation in ambient air.This work provides a convenient strategy on dual-interface engineering for making high-efficiency and stable perovskite platforms.展开更多
The mixing injection of natural gas and pulverized coal into the blast furnaces shows a promising technological approach in the context of global carbon reduction initiatives.Carrier gas and coal pass through the air ...The mixing injection of natural gas and pulverized coal into the blast furnaces shows a promising technological approach in the context of global carbon reduction initiatives.Carrier gas and coal pass through the air inlet of coal lance,and the characteristics of carrier gas affect the flow in the air inlet and the combustion efficiency of coal,so it is very important to study the change of carrier gas charac-teristics in the lower part of blast furnace.By means of numerical simulation,the influence of carrier gas characteristics(injection rate,composition,and temperature)on the mixed combustion of natural gas(NG)and pulverized coal in the tuyere raceway of Russian blast furnace was analyzed.When N_(2) is used as carrier gas,the injection rate of carrier gas is reduced from 4000 to 2000 m3/h,the average tuy-ere temperature is increased(1947.42 to 1963.30 K),the mole fractions of CO and H_(2) are increased,and the burnout rate of pulverized coal is decreased.Increasing the carrier gas temperature is helpful to improve the burnout of pulverized coal.For every 20 K increase of carrier gas temperature,the average temperature in the raceway increases by 20.6 K,which promotes the release and combustion of volat-iles,but the increase of carrier gas temperature from 373 to 393 K only leads to 1.16%burnout change.Considering the transportation characteristics of pulverized coal,it is suggested that the carrier gas temperature should be kept at about 373 K to obtain the best perform-ance.It is worth noting that when air is used as carrier gas,the burnout rate of pulverized coal is increased by 2.69%compared with N_(2).展开更多
Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and ...Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and the operation life of the catalyst.In this work,dahlia-like SWCNHs with N contents ranging from 2.1at%to 4.3at%are controllably synthesized via arc discharge and applied as a carrier of Pt nanoparticles(NPs),denoted as Pt/N-SWCNHs.Pt/N-SWCNHs-2:1(graphite and melamine with the mass ratio of 2:1)exhibits excellent electrocatalytic activity(onset potential=0.95 V).The half-wave potential of Pt/N-SWCNHs-2:1 is only reduced by 2 mV after 3000 cyclic voltammetry cycles.This can be attributed to the enhanced dispersion of Pt NPs and the strong electronic interaction between the N-SWCNHs and Pt,facilitated by the optimal nitrogen doping level.The results of this work offer important perspectives on the design and enhancement of Pt-based electrocatalysts for ORR applications,highlighting the critical role of the nitrogen doping level in balancing the electrocatalytic activity and long-term stability.展开更多
Efficient and stable photocathodes with versatility are of significance in photoassisted lithium-ion batteries(PLIBs),while there is always a request on fast carrier transport in electrochemical active photocathodes.P...Efficient and stable photocathodes with versatility are of significance in photoassisted lithium-ion batteries(PLIBs),while there is always a request on fast carrier transport in electrochemical active photocathodes.Present work proposes a general approach of creating bulk heterojunction to boost the carrier mobility of photocathodes by simply laser assisted embedding of plasmonic nanocrystals.When employed in PLIBs,it was found effective for synchronously enhanced photocharge separation and transport in light charging process.Additionally,experimental photon spectroscopy,finite difference time domain method simulation and theoretical analyses demonstrate that the improved carrier dynamics are driven by the plasmonic-induced hot electron injection from metal to TiO_(2),as well as the enhanced conductivity in TiO2 matrix due to the formation of oxygen vacancies after Schottky contact.Benefiting from these merits,several benchmark values in performance of TiO2-based photocathode applied in PLIBs are set,including the capacity of 276 mAh g^(−1) at 0.2 A g^(−1) under illumination,photoconversion efficiency of 1.276%at 3 A g^(−1),less capacity and Columbic efficiency loss even through 200 cycles.These results exemplify the potential of the bulk heterojunction strategy in developing highly efficient and stable photoassisted energy storage systems.展开更多
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b...The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.展开更多
Nanolipid carriers and traditional emulsion containing chemical sunscreens were prepared using emulsification combined with ultrasonic technology.The nanolipid carriers showed superior performance in sunscreen encapsu...Nanolipid carriers and traditional emulsion containing chemical sunscreens were prepared using emulsification combined with ultrasonic technology.The nanolipid carriers showed superior performance in sunscreen encapsulation,slow release and skin impermeability,and provided an excellent nanolipid slow-release encapsulation system for sunscreens.As observed by transmission electron microscopy,the nanolipid carriers were spherical shape,with smooth surface and uniform distribution,and the particle sizes were mainly concentrated in the range of 230 to 250 nm without agglomeration.The nanolipid carriers significantly improved the sunscreen performance through the synergistic effect of scattering and chemical absorption,and showed better UV stability than traditional sunscreen,indicating their photoprotective function.In vitro release experiments showed that the nano-lipidic carriers exhibited better release control when loaded with octyl methoxycinnamate(OMC)and butylmethoxydibenzoylmethane(BDFM)sunscreens than traditional traditional emulsions,with the cumulative release rate of OMC in the nano-lipidic carriers decreasing by 17.17% to 30.24% within 12 hours,and that of BDFM decreasing by 26.67% to 44.67%.26.67% to 44.16%.The results of the in vitro permeation experiment further confirmed that the nanolipid carriers could effectively encapsulate the sunscreens and prevent them from penetrating the skin barrier,thus reducing the skin irritation.Compared with traditional traditional emulsion,the cumulative penetration of OMC in nanostructured lipid carriers was 2.24μg/cm^(2)in 4 hours,while the cumulative penetration was reduced by 68.05%.The cumulative penetration of BDFM in the nanostructured lipid carrier was 3.24μg/cm^(2),with a 64.04%reduction in cumulative penetration.展开更多
Introduction: Sickle cell disease is one of the most common autosomal recessive inherited diseases. Its prevalence is increasing due to the perpetuity of carriers of the trait who are able to marry. Women aged 18 to 3...Introduction: Sickle cell disease is one of the most common autosomal recessive inherited diseases. Its prevalence is increasing due to the perpetuity of carriers of the trait who are able to marry. Women aged 18 to 35 years constitute the most reproductive age group. This study was conducted with the aim of determining the prevalence of sickle cell trait among women aged 18 to 35 years and the attitude of women carriers towards the choice of a carrier spouse. Materials and methods: This was a cross-sectional descriptive study with analytical aims conducted from March to September 2024 in Kisangani. A total of 215 women aged 18 to 35 years presented for screening for sickle cell trait. This study described the following parameters: Sociodemographic data (age, level of education, socioeconomic level, marital status), obstetric and medical history (obstetric formula, sickle cell disease, high blood pressure, diabetes mellitus, asthma), knowledge of sickle cell disease (etiological classification, transmission, prevention, high-risk marriages, clinical manifestations, progression of the disease), attitude of the woman in relation to the choice of an AS spouse, as well as the reasons justifying each attitude. Results: The prevalence of sickle cell trait was 23.7% (51/215). A total of 64.3% of respondents had accepted the choice of spouse before confirmation of carrier status and 73.8% had refused after confirmation of carrier status. Choice was significantly related to age (p-value = 0.027), occupation (p-value = 0.015), parity (p-value = 0.039) and gesture (p-value = 0.034) before test. The ignorance of the union at risk was associated with the risk (p = 0.005;OR: 9.10;CI 95%: 2.03 - 4.81) of accepting the choice of a spouse carrying the trait. Conclusion: The prevalence of sickle cell trait among women aged 18 to 35 years in Kisangani remains within the limits of that of the general population. The choice of a spouse carrying sickle cell trait is associated with the woman’s age, her profession, parity, gestation and her knowledge about high-risk unions. Screening campaigns and health education sessions enable women carrying sickle cell trait to make a wise choice.展开更多
Cleft palate is a common congenital malformation of the maxillofacial region,and its postoperative speech disorders(such as hypernasality,nasal emission,and articulation errors)can significantly impact patients’commu...Cleft palate is a common congenital malformation of the maxillofacial region,and its postoperative speech disorders(such as hypernasality,nasal emission,and articulation errors)can significantly impact patients’communication abilities and psychological well-being.Traditional speech-language therapy faces challenges such as insufficient personalization of training methods,limited scenarios,and low patient compliance,making it inadequate for long-term rehabilitation needs.The innovative intervention model of a mobile interactive platform combined with games and picture books,through immersive experiences,instant feedback,and engaging designs,holds promise for enhancing patient participation and overall treatment outcomes.Therefore,this paper provides a comprehensive review from five perspectives:the pathological mechanisms and treatment needs of cleft palate speech disorders,the advantages of games and picture books as carriers in cleft palate speech therapy,the technological implementation of mobile interactive platforms,clinical application effects,and current challenges and limitations.The aim is to offer valuable insights for clinical practice and technological development in cleft palate speech rehabilitation.展开更多
Surface states are expected to play a key role in broadband terahertz(THz) emitters, where photoexcited carrier distributions are confined within about 1 μm of the surface. Optical pump and THz probe spectroscopy was...Surface states are expected to play a key role in broadband terahertz(THz) emitters, where photoexcited carrier distributions are confined within about 1 μm of the surface. Optical pump and THz probe spectroscopy was used to study the dynamics of nonequilibrium charge carriers in both textured and non-textured GaAs substrates.Our findings show that the textured surface acts as an antireflective layer, greatly boosting the infrared pump laser's coupling efficiency into the semi-insulating GaAs substrate. Additionally, texturing introduces a trapassisted recombination pathway, speeding up carrier relaxation and thus reducing Joule heating. Under the same pumping and bias field conditions, the coarse-textured GaAs photoconductive antenna shows nearly 7.85 times stronger THz emission amplitude than the non-textured device, along with improvement in signal-to-noise ratio.At a fixed bias field, higher pump power increases photogenerated carrier density, causing bias field screening and subsequent saturation of THz emission. At fixed pump power, when the bias field reaches ~2.5 kV/cm, both THz emission and photocurrent spectra show a clear kink, signaling intervalley scattering from the Γ valley to the L(X) valleys under high electric fields.展开更多
Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive n...Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive noble catalysts.In this work,a new Mg-based metal hydride hydrogenation catalyst,which is composed of MgH_(2),Mg_(2)NiH_(4) and LaH_(3) micro-nano-particles.展开更多
Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step cit...Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step citric acid‐gel method and applied as an oxygen carrier in the CL‐ODH process of ethane to ethylene;moreover,the effects of CuO,ZnO,and MgO as additives were investigated.The properties of the oxygen carriers were characterized using XRD,BET,XPS,H_(2)‐TPR,O_(2)‐TPD,and EPR.Characterization results showed that the addition of additives into Co_(2)O_(3)/LaCoO_(3) increased the amounts of surface chemisorbed oxygen and lattice oxygen.Co_(2)O_(3)/LaCoO_(3) had a strong ability to absorb and release oxygen after adding CuO,ZnO,and MgO,respectively.The performances of the oxygen carriers for CL‐ODH of ethane to ethylene were studied at a reaction temperature of 650℃,atmospheric pressure,and GHSV of 15,000 mL/g·h in eight redox cycles.All the oxygen carriers had 100%ethane conversion,and ZnO‐Co_(2)O_(3)/LaCoO_(3) exhibited the best ethylene selectivity of more than 70%in all the oxygen carriers.It was confirmed that lattice oxygen was mainly responsible for the selectivity of ethylene,and oxygen vacancies were conducive to the migration of lattice oxygen.Most of Zn^(2+) entered into the bulk phase of Co_(2)O_(3)/LaCoO_(3),and formed lots of oxygen vacancies.展开更多
We investigate the carrier, phonon, and spin dynamics in the ferromagnetic semiconductor(In,Fe)Sb using ultrafast optical pump-probe spectroscopy. We discover two anomalies near T^(*)(~40 K) and T^(†)(~200 K) in the p...We investigate the carrier, phonon, and spin dynamics in the ferromagnetic semiconductor(In,Fe)Sb using ultrafast optical pump-probe spectroscopy. We discover two anomalies near T^(*)(~40 K) and T^(†)(~200 K) in the photoexcited carrier dynamics, which can be attributed to the electron-spin and spin-lattice scattering processes influenced by the magnetic phase transition and modifications in magnetic anisotropy. The magnetization change can be revealed by the dynamics of coherent acoustic phonon. We also observe abrupt changes in the photoinduced spin dynamics near T^(*)and T^(†), which not only illustrate the spin-related scatterings closely related to the long-range magnetic order, but also reveal the D'yakonov–Perel and Elliott–Yafet mechanisms dominating at temperatures below and above T^(†), respectively. Our findings provide important insights into the nonequilibrium properties of the photoexcited(In,Fe)Sb.展开更多
This study investigates the crystal structure,microstructure,electronic,thermal transport properties,and thermoelectric performance ofα-MgAgSb synthesized through various ball milling techniques.Variations in synthes...This study investigates the crystal structure,microstructure,electronic,thermal transport properties,and thermoelectric performance ofα-MgAgSb synthesized through various ball milling techniques.Variations in synthesis methods can significantly impact thermoelectric performance.Our findings indicate that impurity phases,particularly the secondary phase Ag_(3)Sb,hinder grain growth and decrease carrier mobility.By systematically adjusting milling conditions,the increased grain size resulting from the suppression of impurity formation improves charge carrier mobility and enhances the power factor.Low-temperature resistivity analysis reveals distinct scattering mechanisms influenced by impurity levels.α-MgAgSb with a tiny content of Sb primarily exhibits electron-electron scattering,whereas higher impurity levels introduce both electron-electron and electron-phonon scattering.Additionally,thermal conductivity analysis using three Effective Medium Theory(EMT)methods shows that the distribution of Ag_(3)Sb increases interfacial resistance.The maximum zT value of 1.36 was achieved in a compound with anα-MgAgSb to Sb ratio of 99%:1%.展开更多
基金Supported by the National Natural Science Foundation of China(52266008,52464057)Applied Basic Research Program of Yunnan Province(202301AT070067)the Yunnan Revitalization Talent Support Program Young Talent Project(XDYC-QNRC-2022-0060)。
文摘Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome the limitations of single ironbased oxygen carriers,including poor cycling stability,low reactivity and susceptibility to sintering,this study employed a dipcoating method to modify Fe_(2)O_(3)/Al_(2)O_(3)oxygen carriers by incorporating three distinct metal additives:Cu,La and Ce.The composite oxygen carriers were systematically characterized and evaluated under redox conditions to investigate the structure-activity relationships between the physicochemical properties,reactivity,and hydrogen production performance.Results revealed that the spinel-phase CuFe_(2)O_(4)exhibited higher reactivity than the perovskite-phase LaFeO_(3)and CeO_(2),promoting the deeper reduction of Fe_(2)O_(3).Fe58Cu2Al exhibited an oxygen storage capacity as high as 6.5 mmol/g.During the CH4 reaction stage,Fe58Cu2Al achieved the highest oxygen loss of 12.1 g/100 g oxygen carrier,accompanied by a syngas yield of 5.15 mmol/g-1.33 times and 1.59 times greater than that of Fe60Al.In the hydrogen production stage,the 2%Cu-modified oxygen carrier demonstrated optimal performance,yielding 5.13 mmol/g of hydrogen,which was 1.51 times that of the pristine sample.Even after ten cycles,the H_(2)yield remained at 3.61 mmol/g,surpassing the single-cycle output of the pristine sample and the H2 purity consistently exceeded 98%.
基金supported by the National Natural Science Foundation of China(82373277).
文摘Delivery carriers serve as a highly efficient approach for precision nutrition and medicine;however,artificial delivery carriers are prone to triggering the immune response and have the disadvantages of poor stability and low bioavailability.Extracellular vesicles(EVs),nucleus-free biological particles composed of phospholipid bilayers secreted by living cells,are a new generation of targeted delivery carriers.In recent years,an increasing number of species have been reported to contain EVs.Among them,food-derived extracellular vesicles(FDEVs)show outstanding comprehensive properties.FDEVs are considered to have great application potential due to their wide range of sources,high yields,absence of human pathogenic pathogens,and ethical concerns.In this review,the preparation,nomenclature,physicochemical characteristics,and preservation methods of FDEVs are discussed,as well as their potential protein markers,bioactivities,and applications as novel targeted delivery carriers of FDEVs from animals,plants,and microorganisms.We also summarized the adverse consequences of FDEVs in current studies,and put forward the problems and challenges in the process of FDEVs research and commercialization.In short,the importance of FDEVs has been highlighted,and FDEVs have good application prospects as a new class of targeted delivery carriers.The current problems should be paid attention to and actively solved.
基金supported by ZTE Industry-University-Institute Cooperation Funds under Grant No.IA20240723011National Natural Science Foundation of China under Grant No.62371123+1 种基金Young Elite Scientists Sponsorship Program of the Beijing High Innovation Plan under Grant No.20251077Research Fund of National Mobile Communications Research Laboratory,Southeast University under Grant No.2023A03。
文摘The radio frequency(RF)fingerprint technique is a robust method for security enhancement of the physical layer by leveraging the unique RF imperfections inherent in various wireless devices.Among these imperfections,the carrier frequency offset(CFO)stands out as a primary RF fingerprint(RFF)of the transmitter,offering the potential to distinguish among different transmitters.However,accurately estimating CFO in time-varying channels poses significant challenges due to multipath effects and Doppler shifts.In this paper,we focus on estimating CFO for wireless device identification in the orthogonal frequency division multiplexing(OFDM)communication system.To achieve precise CFO estimation under time-varying channels,we propose a frequency domain correlation and spline interpolation(FCSI)algorithm.This approach utilizes pilots distributed across different subcarriers to correlate with prior local sequences,facilitating accurate CFO estimation.Classification is then performed based on the Euclidean distance between the prior RFF and the tested RFF dataset.Simulation results demonstrate that the proposed Mconsecutive average method effectively reduces the classification error rate in the challenging high-frequency(HF)skywave channel environment.
文摘The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a collaborative scheduling problem inherent to the operational processes of carrier aircraft,where launch and recovery tasks are conducted concurrently on the flight deck.The objective is to minimize the cumulative weighted waiting time in the air for recovering aircraft and the cumulative weighted delay time for launching aircraft.To tackle this challenge,a multiple population self-adaptive differential evolution(MPSADE)algorithm is proposed.This method features a self-adaptive parameter updating mechanism that is contingent upon population diversity,an asynchronous updating scheme,an individual migration operator,and a global crossover mechanism.Additionally,comprehensive experiments are conducted to validate the effectiveness of the proposed model and algorithm.Ultimately,a comparative analysis with existing operation modes confirms the enhanced efficiency of the collaborative operation mode.
文摘Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.The published version showed“Hongzhen Chen”,whereas the correct spelling should be“Hongzheng Chen”.The correct author name has been provided in this Correction,and the original article[1]has been corrected.
基金supported by the National Key Research and Development Program of China (Grant No.2023YFA1406301)the National Natural Science Foundation of China (Grant Nos.52250308 and 52525205)。
文摘Band inversion induced by spin–orbit coupling in topological semimetals typically generates light charge carriers with high Fermi velocities,which are highly desirable for low-dissipation and coherent quantum transport in topological devices.The presence of these carriers in real materials strongly depends on the Fermi-level position.2M-WSe_(2),with its topological and van der Waals nature,serves as an ideal platform for studying quantum transport in two-dimensional systems,despite the fact that interlayer coupling suppresses the formation of light carriers.In this study,we solvothermally intercalate 1,3-diaminopropane molecules into the interlayer space of 2M-WSe_(2);these molecules effectively adapt to the electronic structure by eliminating interlayer coupling.Simultaneously,slight electron doping via charge transfer results in a small Fermi pocket with an extremely light effective mass,0.04–0.06 me,as revealed by quantum oscillation measurements.This study demonstrates that molecular intercalation is an effective approach for engineering van der Waals topological materials to achieve specific quantum transport properties.
基金the financial support of the National Key Research and Development Plan(2021YFB3302501)the financial support of the National Natural Science Foundation of China(12102077)。
文摘Safe and efficient sortie scheduling on the confined flight deck is crucial for maintaining high combat effectiveness of the aircraft carrier.The primary difficulty exactly lies in the spatiotemporal coordination,i.e.,allocation of limited supporting resources and collision-avoidance between heterogeneous dispatch entities.In this paper,the problem is investigated in the perspective of hybrid flow-shop scheduling problem by synthesizing the precedence,space and resource constraints.Specifically,eight processing procedures are abstracted,where tractors,preparing spots,catapults,and launching are virtualized as machines.By analyzing the constraints in sortie scheduling,a mixed-integer planning model is constructed.In particular,the constraint on preparing spot occupancy is improved to further enhance the sortie efficiency.The basic trajectory library for each dispatch entity is generated and a delayed strategy is integrated to address the collision-avoidance issue.To efficiently solve the formulated HFSP,which is essentially a combinatorial problem with tightly coupled constraints,a chaos-initialized genetic algorithm is developed.The solution framework is validated by the simulation environment referring to the Fort-class carrier,exhibiting higher sortie efficiency when compared to existing strategies.And animation of the simulation results is available at www.bilibili.com/video/BV14t421A7Tt/.The study presents a promising supporting technique for autonomous flight deck operation in the foreseeable future,and can be easily extended to other supporting scenarios,e.g.,ammunition delivery and aircraft maintenance.
基金supported by the National Natural Science Foundation of China(Grant No.62204245,U23A200098)Baima Lake Laboratory Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LBMHD24E020002)+4 种基金Key Research and Development Program of Zhejiang Province(Grant No.2022C01215,2024C01092)China Postdoctoral Science Foundation(Grant No.2023M743620,2024T170960)Key Research and Development Program of Ningbo(Grant No.2023Z151)National Key Research and Development Program of China(Grant No.2024YFB3817304)Zhejiang Provincial Natural Science Foundation of China(Grant No.LY24F040003).
文摘Despite significant advancements in the power conversion efficiency(PCE)of perovskite/silicon tandem solar cells,improving carrier management in top cells remains challenging due to the defective dual interfaces of wide-bandgap perovskite,particularly on textured silicon surfaces.Herein,a series of halide ions(Cl^(-),Br^(-),I^(-))substituted piperazinium salts are designed and synthesized as post-treatment modifiers for perovskite surfaces.Notably,piperazinium chloride induces an asymmetric bidirectional ions distribution from the top to the bottom surface,with large piperazinium cations concentrating at the perovskite surface and small chloride anions migrating downward to accumulate at the buried interface.This results in effective dual-interface defect passivation and energy band modulation,enabling wide-bandgap(1.68 eV)perovskite solar cells to achieve a PCE of 22.3%and a record product of open-circuit voltage×fill factor(84.4%relative to the Shockley-Queisser limit).Furthermore,the device retains 91.3%of its initial efficiency after 1200 h of maximum power point tracking without encapsulation.When integrated with double-textured silicon heterojunction solar cells,a remarkable PCE of 31.5%is achieved for a 1.04 cm^(2) monolithic perovskite/silicon tandem solar cell,exhibiting excellent long-term operational stability(T_(80)=755 h)without encapsulation in ambient air.This work provides a convenient strategy on dual-interface engineering for making high-efficiency and stable perovskite platforms.
基金financially supported by the National Key R&D Program of China(No.2022YFE0208100)the Major Science and Technology Project of Xinjiang Uygur Autonomous Region,China(No.2022A01003)+1 种基金the Key Research and Development Plan of Anhui Province,China(No.202210700037)the National Natural Science Foundation of China(No.52274316).
文摘The mixing injection of natural gas and pulverized coal into the blast furnaces shows a promising technological approach in the context of global carbon reduction initiatives.Carrier gas and coal pass through the air inlet of coal lance,and the characteristics of carrier gas affect the flow in the air inlet and the combustion efficiency of coal,so it is very important to study the change of carrier gas charac-teristics in the lower part of blast furnace.By means of numerical simulation,the influence of carrier gas characteristics(injection rate,composition,and temperature)on the mixed combustion of natural gas(NG)and pulverized coal in the tuyere raceway of Russian blast furnace was analyzed.When N_(2) is used as carrier gas,the injection rate of carrier gas is reduced from 4000 to 2000 m3/h,the average tuy-ere temperature is increased(1947.42 to 1963.30 K),the mole fractions of CO and H_(2) are increased,and the burnout rate of pulverized coal is decreased.Increasing the carrier gas temperature is helpful to improve the burnout of pulverized coal.For every 20 K increase of carrier gas temperature,the average temperature in the raceway increases by 20.6 K,which promotes the release and combustion of volat-iles,but the increase of carrier gas temperature from 373 to 393 K only leads to 1.16%burnout change.Considering the transportation characteristics of pulverized coal,it is suggested that the carrier gas temperature should be kept at about 373 K to obtain the best perform-ance.It is worth noting that when air is used as carrier gas,the burnout rate of pulverized coal is increased by 2.69%compared with N_(2).
基金financially supported by the National Natural Science Foundation of China(Nos.12175089 and 12205127)the Key Research and Development Program of Yunnan Province,China(Nos.202301AU070064 and 202103AF140006)the Yunnan Industrial Innovative Talents Program for“Xingdian Talent Support Plan”,China(No.KKXY202252001).
文摘Nitrogen-doped single-walled carbon nanohorns(N-SWCNHs)can serve as an effective carrier for platinum(Pt)catalysts,which has the potential to improve the electrocatalytic activity of oxygen reduction reaction(ORR)and the operation life of the catalyst.In this work,dahlia-like SWCNHs with N contents ranging from 2.1at%to 4.3at%are controllably synthesized via arc discharge and applied as a carrier of Pt nanoparticles(NPs),denoted as Pt/N-SWCNHs.Pt/N-SWCNHs-2:1(graphite and melamine with the mass ratio of 2:1)exhibits excellent electrocatalytic activity(onset potential=0.95 V).The half-wave potential of Pt/N-SWCNHs-2:1 is only reduced by 2 mV after 3000 cyclic voltammetry cycles.This can be attributed to the enhanced dispersion of Pt NPs and the strong electronic interaction between the N-SWCNHs and Pt,facilitated by the optimal nitrogen doping level.The results of this work offer important perspectives on the design and enhancement of Pt-based electrocatalysts for ORR applications,highlighting the critical role of the nitrogen doping level in balancing the electrocatalytic activity and long-term stability.
基金supported by the project of the National Natural Science Foundation of China(52202115 and 52172101)Guangdong Basic and Applied Basic Research Foundation(2024A1515012325)+2 种基金the Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-MSX1085)the Shaanxi Science and Technology Innovation Team(2023-CXTD-44)the Fundamental Research Funds for the Central Universities(G2022KY0604).
文摘Efficient and stable photocathodes with versatility are of significance in photoassisted lithium-ion batteries(PLIBs),while there is always a request on fast carrier transport in electrochemical active photocathodes.Present work proposes a general approach of creating bulk heterojunction to boost the carrier mobility of photocathodes by simply laser assisted embedding of plasmonic nanocrystals.When employed in PLIBs,it was found effective for synchronously enhanced photocharge separation and transport in light charging process.Additionally,experimental photon spectroscopy,finite difference time domain method simulation and theoretical analyses demonstrate that the improved carrier dynamics are driven by the plasmonic-induced hot electron injection from metal to TiO_(2),as well as the enhanced conductivity in TiO2 matrix due to the formation of oxygen vacancies after Schottky contact.Benefiting from these merits,several benchmark values in performance of TiO2-based photocathode applied in PLIBs are set,including the capacity of 276 mAh g^(−1) at 0.2 A g^(−1) under illumination,photoconversion efficiency of 1.276%at 3 A g^(−1),less capacity and Columbic efficiency loss even through 200 cycles.These results exemplify the potential of the bulk heterojunction strategy in developing highly efficient and stable photoassisted energy storage systems.
文摘The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.
文摘Nanolipid carriers and traditional emulsion containing chemical sunscreens were prepared using emulsification combined with ultrasonic technology.The nanolipid carriers showed superior performance in sunscreen encapsulation,slow release and skin impermeability,and provided an excellent nanolipid slow-release encapsulation system for sunscreens.As observed by transmission electron microscopy,the nanolipid carriers were spherical shape,with smooth surface and uniform distribution,and the particle sizes were mainly concentrated in the range of 230 to 250 nm without agglomeration.The nanolipid carriers significantly improved the sunscreen performance through the synergistic effect of scattering and chemical absorption,and showed better UV stability than traditional sunscreen,indicating their photoprotective function.In vitro release experiments showed that the nano-lipidic carriers exhibited better release control when loaded with octyl methoxycinnamate(OMC)and butylmethoxydibenzoylmethane(BDFM)sunscreens than traditional traditional emulsions,with the cumulative release rate of OMC in the nano-lipidic carriers decreasing by 17.17% to 30.24% within 12 hours,and that of BDFM decreasing by 26.67% to 44.67%.26.67% to 44.16%.The results of the in vitro permeation experiment further confirmed that the nanolipid carriers could effectively encapsulate the sunscreens and prevent them from penetrating the skin barrier,thus reducing the skin irritation.Compared with traditional traditional emulsion,the cumulative penetration of OMC in nanostructured lipid carriers was 2.24μg/cm^(2)in 4 hours,while the cumulative penetration was reduced by 68.05%.The cumulative penetration of BDFM in the nanostructured lipid carrier was 3.24μg/cm^(2),with a 64.04%reduction in cumulative penetration.
文摘Introduction: Sickle cell disease is one of the most common autosomal recessive inherited diseases. Its prevalence is increasing due to the perpetuity of carriers of the trait who are able to marry. Women aged 18 to 35 years constitute the most reproductive age group. This study was conducted with the aim of determining the prevalence of sickle cell trait among women aged 18 to 35 years and the attitude of women carriers towards the choice of a carrier spouse. Materials and methods: This was a cross-sectional descriptive study with analytical aims conducted from March to September 2024 in Kisangani. A total of 215 women aged 18 to 35 years presented for screening for sickle cell trait. This study described the following parameters: Sociodemographic data (age, level of education, socioeconomic level, marital status), obstetric and medical history (obstetric formula, sickle cell disease, high blood pressure, diabetes mellitus, asthma), knowledge of sickle cell disease (etiological classification, transmission, prevention, high-risk marriages, clinical manifestations, progression of the disease), attitude of the woman in relation to the choice of an AS spouse, as well as the reasons justifying each attitude. Results: The prevalence of sickle cell trait was 23.7% (51/215). A total of 64.3% of respondents had accepted the choice of spouse before confirmation of carrier status and 73.8% had refused after confirmation of carrier status. Choice was significantly related to age (p-value = 0.027), occupation (p-value = 0.015), parity (p-value = 0.039) and gesture (p-value = 0.034) before test. The ignorance of the union at risk was associated with the risk (p = 0.005;OR: 9.10;CI 95%: 2.03 - 4.81) of accepting the choice of a spouse carrying the trait. Conclusion: The prevalence of sickle cell trait among women aged 18 to 35 years in Kisangani remains within the limits of that of the general population. The choice of a spouse carrying sickle cell trait is associated with the woman’s age, her profession, parity, gestation and her knowledge about high-risk unions. Screening campaigns and health education sessions enable women carrying sickle cell trait to make a wise choice.
文摘Cleft palate is a common congenital malformation of the maxillofacial region,and its postoperative speech disorders(such as hypernasality,nasal emission,and articulation errors)can significantly impact patients’communication abilities and psychological well-being.Traditional speech-language therapy faces challenges such as insufficient personalization of training methods,limited scenarios,and low patient compliance,making it inadequate for long-term rehabilitation needs.The innovative intervention model of a mobile interactive platform combined with games and picture books,through immersive experiences,instant feedback,and engaging designs,holds promise for enhancing patient participation and overall treatment outcomes.Therefore,this paper provides a comprehensive review from five perspectives:the pathological mechanisms and treatment needs of cleft palate speech disorders,the advantages of games and picture books as carriers in cleft palate speech therapy,the technological implementation of mobile interactive platforms,clinical application effects,and current challenges and limitations.The aim is to offer valuable insights for clinical practice and technological development in cleft palate speech rehabilitation.
基金supported by the National Key Research and Development Program of China (Grant No.2023YFF0719200)the National Natural Science Foundation of China (Grant Nos.62322115,U24A20226,62588201,62435010,and 62335012)+2 种基金the 111 Project (Grant No.D18014)the Key project supported by Science and Technology Commission Shanghai Municipality (Grant No.YDZX20193100004960)Science and Technology Commission of Shanghai Municipality (Grant Nos.22JC1400200 and 21S31907400)。
文摘Surface states are expected to play a key role in broadband terahertz(THz) emitters, where photoexcited carrier distributions are confined within about 1 μm of the surface. Optical pump and THz probe spectroscopy was used to study the dynamics of nonequilibrium charge carriers in both textured and non-textured GaAs substrates.Our findings show that the textured surface acts as an antireflective layer, greatly boosting the infrared pump laser's coupling efficiency into the semi-insulating GaAs substrate. Additionally, texturing introduces a trapassisted recombination pathway, speeding up carrier relaxation and thus reducing Joule heating. Under the same pumping and bias field conditions, the coarse-textured GaAs photoconductive antenna shows nearly 7.85 times stronger THz emission amplitude than the non-textured device, along with improvement in signal-to-noise ratio.At a fixed bias field, higher pump power increases photogenerated carrier density, causing bias field screening and subsequent saturation of THz emission. At fixed pump power, when the bias field reaches ~2.5 kV/cm, both THz emission and photocurrent spectra show a clear kink, signaling intervalley scattering from the Γ valley to the L(X) valleys under high electric fields.
基金supported by the National Key R&D Program of China(No.2023YFB3809100)the Youth Fund Project of Grinm(No.SKHT10422023060280).
文摘Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive noble catalysts.In this work,a new Mg-based metal hydride hydrogenation catalyst,which is composed of MgH_(2),Mg_(2)NiH_(4) and LaH_(3) micro-nano-particles.
基金The funding of this submission came from our laboratory sponsored by the college
文摘Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step citric acid‐gel method and applied as an oxygen carrier in the CL‐ODH process of ethane to ethylene;moreover,the effects of CuO,ZnO,and MgO as additives were investigated.The properties of the oxygen carriers were characterized using XRD,BET,XPS,H_(2)‐TPR,O_(2)‐TPD,and EPR.Characterization results showed that the addition of additives into Co_(2)O_(3)/LaCoO_(3) increased the amounts of surface chemisorbed oxygen and lattice oxygen.Co_(2)O_(3)/LaCoO_(3) had a strong ability to absorb and release oxygen after adding CuO,ZnO,and MgO,respectively.The performances of the oxygen carriers for CL‐ODH of ethane to ethylene were studied at a reaction temperature of 650℃,atmospheric pressure,and GHSV of 15,000 mL/g·h in eight redox cycles.All the oxygen carriers had 100%ethane conversion,and ZnO‐Co_(2)O_(3)/LaCoO_(3) exhibited the best ethylene selectivity of more than 70%in all the oxygen carriers.It was confirmed that lattice oxygen was mainly responsible for the selectivity of ethylene,and oxygen vacancies were conducive to the migration of lattice oxygen.Most of Zn^(2+) entered into the bulk phase of Co_(2)O_(3)/LaCoO_(3),and formed lots of oxygen vacancies.
基金supported by the National Key R&D Program of China (Grant No. 2024YFA1408502)the National Natural Science Foundation of China (Grant Nos. 92365102, 62027807, 12474107, and 12174383)+1 种基金the Chinese Academy of Sciences project for Yong Scientists in Basic Research (Grant No. YSBR-030)the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2024A1515011600)。
文摘We investigate the carrier, phonon, and spin dynamics in the ferromagnetic semiconductor(In,Fe)Sb using ultrafast optical pump-probe spectroscopy. We discover two anomalies near T^(*)(~40 K) and T^(†)(~200 K) in the photoexcited carrier dynamics, which can be attributed to the electron-spin and spin-lattice scattering processes influenced by the magnetic phase transition and modifications in magnetic anisotropy. The magnetization change can be revealed by the dynamics of coherent acoustic phonon. We also observe abrupt changes in the photoinduced spin dynamics near T^(*)and T^(†), which not only illustrate the spin-related scatterings closely related to the long-range magnetic order, but also reveal the D'yakonov–Perel and Elliott–Yafet mechanisms dominating at temperatures below and above T^(†), respectively. Our findings provide important insights into the nonequilibrium properties of the photoexcited(In,Fe)Sb.
基金financially supported by JST Mirai Program(No.JPMJMI19A1).
文摘This study investigates the crystal structure,microstructure,electronic,thermal transport properties,and thermoelectric performance ofα-MgAgSb synthesized through various ball milling techniques.Variations in synthesis methods can significantly impact thermoelectric performance.Our findings indicate that impurity phases,particularly the secondary phase Ag_(3)Sb,hinder grain growth and decrease carrier mobility.By systematically adjusting milling conditions,the increased grain size resulting from the suppression of impurity formation improves charge carrier mobility and enhances the power factor.Low-temperature resistivity analysis reveals distinct scattering mechanisms influenced by impurity levels.α-MgAgSb with a tiny content of Sb primarily exhibits electron-electron scattering,whereas higher impurity levels introduce both electron-electron and electron-phonon scattering.Additionally,thermal conductivity analysis using three Effective Medium Theory(EMT)methods shows that the distribution of Ag_(3)Sb increases interfacial resistance.The maximum zT value of 1.36 was achieved in a compound with anα-MgAgSb to Sb ratio of 99%:1%.
