Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree c...Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.展开更多
We aim to find one highly nontrivial example of the solutions to the vortex fluid dynamical equation on the unit sphere(S^(2))and compare it with the numerical simulation.Since the rigid rotating steady solution for v...We aim to find one highly nontrivial example of the solutions to the vortex fluid dynamical equation on the unit sphere(S^(2))and compare it with the numerical simulation.Since the rigid rotating steady solution for vortex fluids on S^(2)is already known to us,we consider the perturbations above it.After decomposing the perturbation of the vortex number density and vortex charge density into spherical harmonics,we find that the perturbations are propagating waves.To be precise,the velocities for different single-mode vortex number density waves are all the same,while the velocities for single-mode vortex charge density waves depend on the degree of the spherical harmonics l,which is a signal of the existence of dispersion.Meanwhile,we find that there is a beat phenomenon for the positive(or negative)vortex density wave.Numerical simulation based on the canonical equations for the point vortex model agrees perfectly with our theoretical calculations.展开更多
Acetone is a common volatile organic compound that can cause harm to human health when inhaled in small amounts.Therefore,the development of fast response and low detection limit acetone sensors becomes crucial.In thi...Acetone is a common volatile organic compound that can cause harm to human health when inhaled in small amounts.Therefore,the development of fast response and low detection limit acetone sensors becomes crucial.In this study,a core-shell spherical TiO_(2) sensor with a rich pore structure was designed.This sensor exhibited excellent sensing properties,including higher responsiveness(100 ppm acetone,R_(a)/R_(g)=80),lower detection limit(10 ppb)and short response time(8 s).The problem is that the sensing mechanism between TiO_(2) and acetone is not thoroughly analyzed.To gain further insight,the interaction process of TiO_(2) core-shell spheres and acetone under varying oxygen content environments was investigated by dynamic testing,X-ray photoelectron spectroscopy,in-situ Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry.The research results show that acetone not only adsorbs on the surface of the material and reacts with adsorbed oxygen,but also undergoes catalytic oxidation reaction with TiO_(2) core-shell spheres.Significantly,in high oxygen content environments,acetone undergoes oxidation to form intermediates such as acids and anhydrides that are difficult to desorpt on the surface of the material,thus prolonging the recovery time of the sensor.The discovery of this sensing process will provide some guidance for the design of acetone sensing materials in the future.Meanwhile,this also imparts valuable references and insights for the investigation of the mechanism and application of other sensitive metal oxide materials.展开更多
During nearly 200 years of development in the knowledge of Brownian motion,the Janus sphere,as a typical Brownian particle with special surface properties,has been widely studied in the past few decades.A standard Jan...During nearly 200 years of development in the knowledge of Brownian motion,the Janus sphere,as a typical Brownian particle with special surface properties,has been widely studied in the past few decades.A standard Janus sphere possesses two distinct surfaces.These two surfaces elicit different hydrodynamic interactions with ambient fluids or other interactions in response to environmental stimuli,such as chemical gradients,magnetic fields,and even light.The diffusion of Janus spheres,particularly when controlled by a remotely applied field,has inspired various applications,ranging from the design of micro-swimmers and novel procedures for probing the mechanical properties of suspensions to the fabrication of composites with enhanced performance.In this work,we report a systematic analysis of field-controlled diffusion of Janus spheres.Commencing with stochastic differential equations of motion at the microscale,we derive a coarse-grained Fokker-Planck equation at the macroscale,describing the evolution of the probability distribution function of the Janus sphere in terms of its position and orientation.Leveraging the concept of the hydrodynamic center,we derive,for the first time,explicit generalized Stokes-Einstein relations for long-time effective diffusivity,incorporating the effects of both the surface discontinuity of the Janus sphere and the external fields.The formulae enable predictions of the effective diffusivity as it varies with the slip length and characteristic angle of Janus spheres,and reveal the impact of an aligning potential field on the diffusion coefficients both parallel and perpendicular to the direction of the field.This work not only deepens the understanding of field-controlled diffusion of Janus particles,but also holds a meaningful impact on the future applications in microfluidics and related fields.展开更多
BACKGROUND Aloe vera has been used as a traditional herbal therapy for wound management and dermatological conditions worldwide for thousands of years.Scientific evidence has confirmed that acemannan,the bioactive com...BACKGROUND Aloe vera has been used as a traditional herbal therapy for wound management and dermatological conditions worldwide for thousands of years.Scientific evidence has confirmed that acemannan,the bioactive compound in aloe vera gel,exhibits significant anti-inflammatory and immunomodulatory properties that enhance tissue regeneration.This case report describes the successful application of an innovative acemannan-enriched glycolipid sphere dressing derived from aloe vera gel in diabetic foot ulcer(DFU)treatment,which achieved a clinically remarkable outcome.CASE SUMMARY An 80-year-old female patient with a 20-year history of type 2 diabetes mellitus experienced recurrent diabetic foot pain for 15 years.She had multiple hospitalizations due to acute infections and poorly controlled hyperglycemia.Long-term treatments included metformin and gliclazide.Upon presentation,she had a nonhealing wound on her left dorsal foot,diagnosed as a severe DFU(Texas classification:Grade II,stage D).She declined amputation and opted for conservative treatment.The medical team applied an acemannan-enriched glycolipid sphere dressing five times daily to the left calf and foot,avoiding the wound area.Frequency was reduced to three times daily after scab formation.Weight-bearing on the injured foot was avoided.Through in-person and online consultations,the team managed her lifestyle and diet,emphasizing natural foods.After 5 months,the DFU healed without significant scarring or functional loss.No recurrence was observed during the 2-year follow-up.Acemannan-enriched glycolipid sphere dressings promote DFU healing.This suggests the potential of these dressings for treating other refractory wounds.展开更多
The exsolution method has garnered significant attention owing to its high efficacy in developing highly efficient and stable metal nanocatalysts.Herein,a versatile exsolution approach is developed to embed size-tunab...The exsolution method has garnered significant attention owing to its high efficacy in developing highly efficient and stable metal nanocatalysts.Herein,a versatile exsolution approach is developed to embed size-tunable metal nanocatalysts within a conductive metal pnictogenide matrix.The gas-phase reaction of Ru-substituted Ni-Fe-layered-double-hydroxide(Ni_(2)Fe_(1-x)Ru_(x)-LDH)with pnictogenation reagents leads to the exsolution of Ru metal nanocatalysts and a phase transformation into metal pnictogenide.The variation in reactivity of pnictogenation reagents allows for control over the size of the exsolved metal nanocatalysts(i.e.,nanoclusters for nitridation and single atoms for phosphidation),underscoring the effectiveness of the pnictogenation-driven exsolution strategy in stabilizing size-tunable metal nanocatalysts.The Ru-exsolved nickel-iron nitride/phosphide demonstrates outstanding electrocatalyst activity for the hydrogen evolution reaction,exhibiting a smaller overpotential and higher stability than Ru-deposited homologs.The high efficacy of pnictogenation-assisted exsolution in optimizing the performance and stability of Ru metal nanocatalysts is ascribed to the efficient interfacial electronic interaction between Ru metals and nitride/phosphide ions assisted by the inner sphere mechanism.In situ spectroscopic analyses highlight that exsolved Ru single atoms facilitate more efficient electron transfer to the reactants than the exsolved Ru nanoclusters,which is primarily responsible for the superior impact of the phosphidation-driven exsolution approach.展开更多
Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment...Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd(Pd@NHCS-X,X:600–800)nanoreactors for catalytic HDO of biomass-derived vanillin in water.The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts.Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h^(–1)and a low apparent activation energy of 18.63 kJ/mol.The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations.It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction(EMSI)and produced numerous electron-rich active Pd centers,which not only intensified the dissociation and activation of H2 molecules,but also substantially improved the activation capability of vanillin via the enhanced adsorption of–C=O group.The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water.Additionally,the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds.The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high-performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.展开更多
Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solv...Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solve this problem,in this work,we developed a biaxial rotation grouting process for deep-sea ceramic hollow buoyancy spheres,which improves the drawbacks of the traditional rotary grouting method that results in poor wall thickness uniformity of the hollow spheres due to its irregular rotational processing.In this paper,an experimental study was carried out to investigate the effects of different rotational methods,rotational speeds,rotational time,solid phase content,etc.on the wall thickness uniformity of ceramic hollow spheres.The results show that the hollow floating balls prepared by the biaxial rotation method have the lowest wall thickness standard deviation(0.04)when the rotation speed is 60 rpm,the molding time is 8 min,and the solid phase content is 70 wt%.After the hydrostatic pressure test of 120 MPa,the hydrostatic compressive strength of hollow spheres prepared by the biaxial rotation method was increased by 31.67%compared with that of the traditional process.展开更多
This study presents a novel Li metal host material with a unique hollow nano-spherical structure that incorporates Ag nano-seeds into a graphitic carbon nitride(g-C_(3)N_(4))shell layer,referred to as g-C_(3)N_(4)@Ag ...This study presents a novel Li metal host material with a unique hollow nano-spherical structure that incorporates Ag nano-seeds into a graphitic carbon nitride(g-C_(3)N_(4))shell layer,referred to as g-C_(3)N_(4)@Ag hollow spheres.The g-C_(3)N_(4)@Ag spheres provide a managed internal site for Li metal encapsulation and promote stable Li plating.The g-C_(3)N_(4) spheres are uniformly coated using polydopamine,which has an adhesive nature,to enhance lithium plating/stripping stability.The strategic presence of Ag nano-seeds eliminates the nucleation barrier,properly directing Li growth within the hollow spheres.This design facilitates highly reversible and consistent lithium deposition,offering a promising direction for the production of high-performance lithium metal anodes.These well-designed g-C_(3)N_(4)@Ag hollow spheres ensure stable Li plating/stripping kinetics over more than 500 cycles with a high coulombic efficiency of over 97%.Furthermore,a full cell made using LiNi_(0.90)Co_(0.07)Mn_(0.03)O_(2) and Li-g-C_(3)N_(4)@Ag host electrodes demonstrated highly competitive performance over 200 cycles,providing a guide for the implementation of this technology in advanced lithium metal batteries.展开更多
Spherical objects are widely used in target localization applications,and the existing sphere localization methods with cameras or total stations both have some limitations.A new high-precision sphere localization met...Spherical objects are widely used in target localization applications,and the existing sphere localization methods with cameras or total stations both have some limitations.A new high-precision sphere localization method with a theodolite is proposed in this paper.From the view point of the theodolite,the contour points of a sphere with a known radius are measured as latitude-longitude coordinates.It is observed that the center of the target sphere is located on a cylindrical surface constructed with the latitude-longitude coordinates,and therefore the latitude-longitude coordinates of at least three contour points can be used to construct a set of ternary quadratic equations.The Gröbner basis method is used to compute at most four real solutions of the sphere center coordinates.To distinguish the only meaningful solution from the other possible real solutions,a pre-processing of the measured longitude values is also proposed.The factors affecting the positioning accuracy of the sphere center are evaluated in simulation experiments,which are used to obtain an empirical estimation model of the positioning error.Real data experiments are also performed and the results show that the proposed method can achieve high localization precision.展开更多
The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)...The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)and hybrid-order Poincarésphere(HyOPS)has provided a systematic description of VVB.However,the generation of arbitrary VVBs on a HOPS and a HyOPS via a metasurface lacks a unified design framework,despite numerous reported approaches.We present a unified design framework incorporating all design parameters(e.g.,focal lengths and orders)of arbitrary HOPS and HyOPS beams into a single equation.In proof-of-concept experiments,we experimentally demonstrated four metasurfaces to generate arbitrary beams on the fifth-order HOPS(nonfocused and tightly focused,NA 0.89),0-2 order,and 0-1 order HyOPS.We showed HOPS beams’propagation and focusing properties,the superresolution focusing characteristics of the first-order cylindrical VVBs,and the different focusing properties of integerorder and fractional-order cylindrical VVBs.The simplicity and feasibility of the proposed design framework make it a potential catalyst for arbitrary VVBs using metasurfaces in applications of optical imaging,communication,and optical trapping.展开更多
The emergence of new media with multiple platforms has abundantly adjusted the socio-political perspectives in such a way that our everyday conducts and professionalism point of views are entrenched over technological...The emergence of new media with multiple platforms has abundantly adjusted the socio-political perspectives in such a way that our everyday conducts and professionalism point of views are entrenched over technological diffusion.The young people remain the potential users on the social media,considering their primary bases for daily accomplishments,owing to the novel features and realistic methods available.As an entry point,this paper intends to draw the conception of the public sphere,whereby the notion of publics is vital on abstracting the sphere of the internet,in which abundant spheres meant for the multiple clusters embark on political communication for their ways distinctly.It’s the ideal realm which converges the peripheral spheres into the inclusive domain through communicative actions.In the developing countries,the youths along with minorities’engagement and reliance on the internet have been ominously mounting,comprehensive for political identities and rationalizing their civic opinions.Polling discussion on running candidates and political parties’manifestations are common during the general election and some diaspora communities and further foreign activists play a part in political affairs of the countries.Thus,this article aims at tracing the potential civil integrity for youths with political information efficacy fostered on digital public spheres,by which traditional media are politically run-downed,remoted by draconian legal framework and commercial determinants.Besides,this paper argues about the offline publics which are ideally distant,and thus far implies to the narrow unitary sphere theorization owing to the technology division which so far entails partial civic life.展开更多
In this work,Dy_(2)O_(3)rods and layered Dy_(2)WO_(6)heterostructure were effectively interconnected by carbon spheres named Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite with a confined interface and it was fabricated...In this work,Dy_(2)O_(3)rods and layered Dy_(2)WO_(6)heterostructure were effectively interconnected by carbon spheres named Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite with a confined interface and it was fabricated using a simple solvothermal approach.These ternary nanocomposites were investigated by X-ray diffraction(XRD),UV-visible diffuse-reflectance spectroscopy(UV-DRS),Fourier transform-infrared spectroscopy(FT-IR),Raman,field emission scanning electron microscopy(FESEM)with energy disperse spectroscopy(EDS),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS)analyses systematically.The XRD data expose that the synthesized materials are formed with a virtuous crystalline state.The charge storage properties and electrochemical performances of the as-synthesized nanocomposites and pure components were assessed with the help of cyclic voltammogram(CV),galvanostatic charge-discharge studies(GCD),and electrochemical impedance studies(EIS),respectively.The rare-earth-based novel Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite as wo rking electrodes established commendable electrochemical perfo rmances with a maximum specific capacitance value of 123 F/g at a current density of 0.4 A/g in 2.0 mol/L aqueous KOH solution.According to the stability measurements,it was observed that the initial capacitance was maintained at~93%even after 2500 cycles,indicating that good electrochemical stability with the lowest internal resistance values was obtained from EIS analysis.The electrochemical measurements suggest that the Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite enables great competence and can be used as alternative electrode material in supercapacitor devices to avail high energy efficiency in a sustainable approach.展开更多
Different-sized hollow SiO2 spheres of 249–1348 nm in diameter were successfully prepared by using Na2SiO3 as the precursor and using polystyrene and polystyrene-methyl acrylic acid latexes as the templates. The diam...Different-sized hollow SiO2 spheres of 249–1348 nm in diameter were successfully prepared by using Na2SiO3 as the precursor and using polystyrene and polystyrene-methyl acrylic acid latexes as the templates. The diameter and shell thickness of the hollow SiO2 spheres increase with increasing the latex template diameter at a given mass ratio of SiO2 to latex template. The diameter and shell thickness of the hollow SiO2 spheres also increase with increasing the mass ratios of SiO2 to latex template. The presence of carboxylic acid groups on the surfaces of polystyrene-methyl acrylic acid latex templates favors the formation of dense and uniform SiO2 shells. The hollow SiO2 sphere is constructed by mesoporous shell with large specific surface area. When glyphosate is used as a release model chemical, glyphosate release rate is tuned by varying the shell thickness.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22279047)the Instrumental Analysis Center of Jiangsu University of Science and Technology。
文摘Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.
基金supported by the Scientific research projects of Hunan Provincial Department of Education(Grant Nos.22A0477 and 20B273)。
文摘We aim to find one highly nontrivial example of the solutions to the vortex fluid dynamical equation on the unit sphere(S^(2))and compare it with the numerical simulation.Since the rigid rotating steady solution for vortex fluids on S^(2)is already known to us,we consider the perturbations above it.After decomposing the perturbation of the vortex number density and vortex charge density into spherical harmonics,we find that the perturbations are propagating waves.To be precise,the velocities for different single-mode vortex number density waves are all the same,while the velocities for single-mode vortex charge density waves depend on the degree of the spherical harmonics l,which is a signal of the existence of dispersion.Meanwhile,we find that there is a beat phenomenon for the positive(or negative)vortex density wave.Numerical simulation based on the canonical equations for the point vortex model agrees perfectly with our theoretical calculations.
基金supported by the National Natural Science Foundation of China(Nos.21771060 and 61271126)the International Science&Technology Cooperation Program of China(No.2016YFE0115100)+2 种基金Heilongjiang Provincial Natural Science Foundation of China(No.LH_(2)023B021)Reform and Development Fund Project of Local University supported by the Central Government,Heilongjiang Touyan Innovation Team Program,New Era Excellent Master’s and Doctoral Dissertations of Heilongjiang Province(No.LJYXL2023-020)Basic Scientific Research Project for Heilongjiang Provincial Colleges and Universities(No.2023-KYYWF-1482).
文摘Acetone is a common volatile organic compound that can cause harm to human health when inhaled in small amounts.Therefore,the development of fast response and low detection limit acetone sensors becomes crucial.In this study,a core-shell spherical TiO_(2) sensor with a rich pore structure was designed.This sensor exhibited excellent sensing properties,including higher responsiveness(100 ppm acetone,R_(a)/R_(g)=80),lower detection limit(10 ppb)and short response time(8 s).The problem is that the sensing mechanism between TiO_(2) and acetone is not thoroughly analyzed.To gain further insight,the interaction process of TiO_(2) core-shell spheres and acetone under varying oxygen content environments was investigated by dynamic testing,X-ray photoelectron spectroscopy,in-situ Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry.The research results show that acetone not only adsorbs on the surface of the material and reacts with adsorbed oxygen,but also undergoes catalytic oxidation reaction with TiO_(2) core-shell spheres.Significantly,in high oxygen content environments,acetone undergoes oxidation to form intermediates such as acids and anhydrides that are difficult to desorpt on the surface of the material,thus prolonging the recovery time of the sensor.The discovery of this sensing process will provide some guidance for the design of acetone sensing materials in the future.Meanwhile,this also imparts valuable references and insights for the investigation of the mechanism and application of other sensitive metal oxide materials.
基金Project supported by the National Natural Science Foundation of China(Nos.12302079 and 11521202)the National Natural Science Foundation of U.S.A.(No.DMS-2306254)。
文摘During nearly 200 years of development in the knowledge of Brownian motion,the Janus sphere,as a typical Brownian particle with special surface properties,has been widely studied in the past few decades.A standard Janus sphere possesses two distinct surfaces.These two surfaces elicit different hydrodynamic interactions with ambient fluids or other interactions in response to environmental stimuli,such as chemical gradients,magnetic fields,and even light.The diffusion of Janus spheres,particularly when controlled by a remotely applied field,has inspired various applications,ranging from the design of micro-swimmers and novel procedures for probing the mechanical properties of suspensions to the fabrication of composites with enhanced performance.In this work,we report a systematic analysis of field-controlled diffusion of Janus spheres.Commencing with stochastic differential equations of motion at the microscale,we derive a coarse-grained Fokker-Planck equation at the macroscale,describing the evolution of the probability distribution function of the Janus sphere in terms of its position and orientation.Leveraging the concept of the hydrodynamic center,we derive,for the first time,explicit generalized Stokes-Einstein relations for long-time effective diffusivity,incorporating the effects of both the surface discontinuity of the Janus sphere and the external fields.The formulae enable predictions of the effective diffusivity as it varies with the slip length and characteristic angle of Janus spheres,and reveal the impact of an aligning potential field on the diffusion coefficients both parallel and perpendicular to the direction of the field.This work not only deepens the understanding of field-controlled diffusion of Janus particles,but also holds a meaningful impact on the future applications in microfluidics and related fields.
文摘BACKGROUND Aloe vera has been used as a traditional herbal therapy for wound management and dermatological conditions worldwide for thousands of years.Scientific evidence has confirmed that acemannan,the bioactive compound in aloe vera gel,exhibits significant anti-inflammatory and immunomodulatory properties that enhance tissue regeneration.This case report describes the successful application of an innovative acemannan-enriched glycolipid sphere dressing derived from aloe vera gel in diabetic foot ulcer(DFU)treatment,which achieved a clinically remarkable outcome.CASE SUMMARY An 80-year-old female patient with a 20-year history of type 2 diabetes mellitus experienced recurrent diabetic foot pain for 15 years.She had multiple hospitalizations due to acute infections and poorly controlled hyperglycemia.Long-term treatments included metformin and gliclazide.Upon presentation,she had a nonhealing wound on her left dorsal foot,diagnosed as a severe DFU(Texas classification:Grade II,stage D).She declined amputation and opted for conservative treatment.The medical team applied an acemannan-enriched glycolipid sphere dressing five times daily to the left calf and foot,avoiding the wound area.Frequency was reduced to three times daily after scab formation.Weight-bearing on the injured foot was avoided.Through in-person and online consultations,the team managed her lifestyle and diet,emphasizing natural foods.After 5 months,the DFU healed without significant scarring or functional loss.No recurrence was observed during the 2-year follow-up.Acemannan-enriched glycolipid sphere dressings promote DFU healing.This suggests the potential of these dressings for treating other refractory wounds.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2023-00208355,RS-2024-00439825,and 2022M3H4A408610313)supported by the Global Science Research Center Program(RS-2024-00411134)+1 种基金funded by the National Research Foundation of KoreaThe experiments at PAL were supported in part by MOST and POSTECH。
文摘The exsolution method has garnered significant attention owing to its high efficacy in developing highly efficient and stable metal nanocatalysts.Herein,a versatile exsolution approach is developed to embed size-tunable metal nanocatalysts within a conductive metal pnictogenide matrix.The gas-phase reaction of Ru-substituted Ni-Fe-layered-double-hydroxide(Ni_(2)Fe_(1-x)Ru_(x)-LDH)with pnictogenation reagents leads to the exsolution of Ru metal nanocatalysts and a phase transformation into metal pnictogenide.The variation in reactivity of pnictogenation reagents allows for control over the size of the exsolved metal nanocatalysts(i.e.,nanoclusters for nitridation and single atoms for phosphidation),underscoring the effectiveness of the pnictogenation-driven exsolution strategy in stabilizing size-tunable metal nanocatalysts.The Ru-exsolved nickel-iron nitride/phosphide demonstrates outstanding electrocatalyst activity for the hydrogen evolution reaction,exhibiting a smaller overpotential and higher stability than Ru-deposited homologs.The high efficacy of pnictogenation-assisted exsolution in optimizing the performance and stability of Ru metal nanocatalysts is ascribed to the efficient interfacial electronic interaction between Ru metals and nitride/phosphide ions assisted by the inner sphere mechanism.In situ spectroscopic analyses highlight that exsolved Ru single atoms facilitate more efficient electron transfer to the reactants than the exsolved Ru nanoclusters,which is primarily responsible for the superior impact of the phosphidation-driven exsolution approach.
文摘Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd(Pd@NHCS-X,X:600–800)nanoreactors for catalytic HDO of biomass-derived vanillin in water.The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts.Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h^(–1)and a low apparent activation energy of 18.63 kJ/mol.The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations.It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction(EMSI)and produced numerous electron-rich active Pd centers,which not only intensified the dissociation and activation of H2 molecules,but also substantially improved the activation capability of vanillin via the enhanced adsorption of–C=O group.The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water.Additionally,the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds.The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high-performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.
基金Funded by the Key Research and Development Program of Shandong Province(No.2020JMRH0101)。
文摘Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solve this problem,in this work,we developed a biaxial rotation grouting process for deep-sea ceramic hollow buoyancy spheres,which improves the drawbacks of the traditional rotary grouting method that results in poor wall thickness uniformity of the hollow spheres due to its irregular rotational processing.In this paper,an experimental study was carried out to investigate the effects of different rotational methods,rotational speeds,rotational time,solid phase content,etc.on the wall thickness uniformity of ceramic hollow spheres.The results show that the hollow floating balls prepared by the biaxial rotation method have the lowest wall thickness standard deviation(0.04)when the rotation speed is 60 rpm,the molding time is 8 min,and the solid phase content is 70 wt%.After the hydrostatic pressure test of 120 MPa,the hydrostatic compressive strength of hollow spheres prepared by the biaxial rotation method was increased by 31.67%compared with that of the traditional process.
基金supported by the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(No.GTL24011-000)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2023-00272863)supported by Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(P0012748,HRD Program for Industrial Innovation)。
文摘This study presents a novel Li metal host material with a unique hollow nano-spherical structure that incorporates Ag nano-seeds into a graphitic carbon nitride(g-C_(3)N_(4))shell layer,referred to as g-C_(3)N_(4)@Ag hollow spheres.The g-C_(3)N_(4)@Ag spheres provide a managed internal site for Li metal encapsulation and promote stable Li plating.The g-C_(3)N_(4) spheres are uniformly coated using polydopamine,which has an adhesive nature,to enhance lithium plating/stripping stability.The strategic presence of Ag nano-seeds eliminates the nucleation barrier,properly directing Li growth within the hollow spheres.This design facilitates highly reversible and consistent lithium deposition,offering a promising direction for the production of high-performance lithium metal anodes.These well-designed g-C_(3)N_(4)@Ag hollow spheres ensure stable Li plating/stripping kinetics over more than 500 cycles with a high coulombic efficiency of over 97%.Furthermore,a full cell made using LiNi_(0.90)Co_(0.07)Mn_(0.03)O_(2) and Li-g-C_(3)N_(4)@Ag host electrodes demonstrated highly competitive performance over 200 cycles,providing a guide for the implementation of this technology in advanced lithium metal batteries.
基金supported in part by the National Natural Science Foundation of China under Grants 61703373,61873246,U1504604in part by the Key research project of Henan Province Universities under Grant 19A413014.
文摘Spherical objects are widely used in target localization applications,and the existing sphere localization methods with cameras or total stations both have some limitations.A new high-precision sphere localization method with a theodolite is proposed in this paper.From the view point of the theodolite,the contour points of a sphere with a known radius are measured as latitude-longitude coordinates.It is observed that the center of the target sphere is located on a cylindrical surface constructed with the latitude-longitude coordinates,and therefore the latitude-longitude coordinates of at least three contour points can be used to construct a set of ternary quadratic equations.The Gröbner basis method is used to compute at most four real solutions of the sphere center coordinates.To distinguish the only meaningful solution from the other possible real solutions,a pre-processing of the measured longitude values is also proposed.The factors affecting the positioning accuracy of the sphere center are evaluated in simulation experiments,which are used to obtain an empirical estimation model of the positioning error.Real data experiments are also performed and the results show that the proposed method can achieve high localization precision.
基金the Chinese Scholarship Council is acknowledged.This work was supported by the UK’s Engineering and Physical Sciences Research Council(Grant Nos.EP/V000624/1,EP/X03495X/1,EP/X041166/1,and EP/T02643X/1)the Royal Society(Grant No.RG\R2\232531).
文摘The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)and hybrid-order Poincarésphere(HyOPS)has provided a systematic description of VVB.However,the generation of arbitrary VVBs on a HOPS and a HyOPS via a metasurface lacks a unified design framework,despite numerous reported approaches.We present a unified design framework incorporating all design parameters(e.g.,focal lengths and orders)of arbitrary HOPS and HyOPS beams into a single equation.In proof-of-concept experiments,we experimentally demonstrated four metasurfaces to generate arbitrary beams on the fifth-order HOPS(nonfocused and tightly focused,NA 0.89),0-2 order,and 0-1 order HyOPS.We showed HOPS beams’propagation and focusing properties,the superresolution focusing characteristics of the first-order cylindrical VVBs,and the different focusing properties of integerorder and fractional-order cylindrical VVBs.The simplicity and feasibility of the proposed design framework make it a potential catalyst for arbitrary VVBs using metasurfaces in applications of optical imaging,communication,and optical trapping.
文摘The emergence of new media with multiple platforms has abundantly adjusted the socio-political perspectives in such a way that our everyday conducts and professionalism point of views are entrenched over technological diffusion.The young people remain the potential users on the social media,considering their primary bases for daily accomplishments,owing to the novel features and realistic methods available.As an entry point,this paper intends to draw the conception of the public sphere,whereby the notion of publics is vital on abstracting the sphere of the internet,in which abundant spheres meant for the multiple clusters embark on political communication for their ways distinctly.It’s the ideal realm which converges the peripheral spheres into the inclusive domain through communicative actions.In the developing countries,the youths along with minorities’engagement and reliance on the internet have been ominously mounting,comprehensive for political identities and rationalizing their civic opinions.Polling discussion on running candidates and political parties’manifestations are common during the general election and some diaspora communities and further foreign activists play a part in political affairs of the countries.Thus,this article aims at tracing the potential civil integrity for youths with political information efficacy fostered on digital public spheres,by which traditional media are politically run-downed,remoted by draconian legal framework and commercial determinants.Besides,this paper argues about the offline publics which are ideally distant,and thus far implies to the narrow unitary sphere theorization owing to the technology division which so far entails partial civic life.
基金supported by Selective Excellence Research Initiative-2023,SRM Institute of Science and Technology(SRMIST/R/AR(A)/SERI2023/174/26-3944)。
文摘In this work,Dy_(2)O_(3)rods and layered Dy_(2)WO_(6)heterostructure were effectively interconnected by carbon spheres named Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite with a confined interface and it was fabricated using a simple solvothermal approach.These ternary nanocomposites were investigated by X-ray diffraction(XRD),UV-visible diffuse-reflectance spectroscopy(UV-DRS),Fourier transform-infrared spectroscopy(FT-IR),Raman,field emission scanning electron microscopy(FESEM)with energy disperse spectroscopy(EDS),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS)analyses systematically.The XRD data expose that the synthesized materials are formed with a virtuous crystalline state.The charge storage properties and electrochemical performances of the as-synthesized nanocomposites and pure components were assessed with the help of cyclic voltammogram(CV),galvanostatic charge-discharge studies(GCD),and electrochemical impedance studies(EIS),respectively.The rare-earth-based novel Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite as wo rking electrodes established commendable electrochemical perfo rmances with a maximum specific capacitance value of 123 F/g at a current density of 0.4 A/g in 2.0 mol/L aqueous KOH solution.According to the stability measurements,it was observed that the initial capacitance was maintained at~93%even after 2500 cycles,indicating that good electrochemical stability with the lowest internal resistance values was obtained from EIS analysis.The electrochemical measurements suggest that the Dy_(2)O_(3)/Dy_(2)WO_(6)/C-sph nanocomposite enables great competence and can be used as alternative electrode material in supercapacitor devices to avail high energy efficiency in a sustainable approach.
基金Projects (11KJB530002, CX10B-259Z) supported by Research Funds from Jiangsu Provincial Department of Education, ChinaProject (10zxfk35) supported by Sichuan Province Nonmetallic Composites and Functional Materials Key Laboratory Project, China
文摘Different-sized hollow SiO2 spheres of 249–1348 nm in diameter were successfully prepared by using Na2SiO3 as the precursor and using polystyrene and polystyrene-methyl acrylic acid latexes as the templates. The diameter and shell thickness of the hollow SiO2 spheres increase with increasing the latex template diameter at a given mass ratio of SiO2 to latex template. The diameter and shell thickness of the hollow SiO2 spheres also increase with increasing the mass ratios of SiO2 to latex template. The presence of carboxylic acid groups on the surfaces of polystyrene-methyl acrylic acid latex templates favors the formation of dense and uniform SiO2 shells. The hollow SiO2 sphere is constructed by mesoporous shell with large specific surface area. When glyphosate is used as a release model chemical, glyphosate release rate is tuned by varying the shell thickness.
