The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological d...The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological data of these particles has became a key focus in wear debris analysis.Herein,we develop a novel multi-view polarization-sensitive optical coherence tomography(PS-OCT)method to achieve accurate 3D morphology detection and reconstruction of aero-engine lubricant wear particles,effectively resolving occlusion-induced information loss while enabling material-specific characterization.The particle morphology is captured by multi-view imaging,followed by filtering,sharpening,and contour recognition.The method integrates advanced registration algorithms with Poisson reconstruction to generate high-precision 3D models.This approach not only provides accurate 3D morphological reconstruction but also mitigates information loss caused by particle occlusion,ensuring model completeness.Furthermore,by collecting polarization characteristics of typical metals and their oxides in aero-engine lubricants,this work comprehensively characterizes and comparatively analyzes particle polarization properties using Stokes vectors,polarization uniformity,and cumulative phase retardation,and obtains a three-dimensional model containing polarization information.Ultimately,the proposed method enables multidimensional information acquisition for the reliable identification of abrasive particle types.展开更多
Researching the dispersion as well as the stability of metals on the oxide surfaces is essentially important for understanding the interaction mecha-nisms at the metal/oxide interfaces and thus optimizing the activiti...Researching the dispersion as well as the stability of metals on the oxide surfaces is essentially important for understanding the interaction mecha-nisms at the metal/oxide interfaces and thus optimizing the activities of the heterogeneous catalysts.Here in this work,we have investigated the growth behavior of Pd particles on the polar surfaces of ZnO with scanning tunneling microscopy(STM).By systematically varying the coverages as well as the annealing temperatures,we found that at room temperature Pd tends to form three-dimensional(3D)round particles on the ZnO(000)surface but grow into monolayer two-dimensional(2D)hexagonal islands on the ZnO(0001)surface.During annealing processes,the Pd particles on ZnO(000)aggregate gently while maintaining the 3D morphology in the mild temperature range but then quickly transform in-to tall hexagonal islands at elevated temperatures.In contrast,the segregation of Pd islands on ZnO(0001)occurs gradually along with the temperature rising without changing the 2D morphology.These results directly reflect the different interaction strengths of Pd on the dis-tinct ZnO polar surfaces.They also provide important input for understanding the facet-de-pendent catalytic mechanisms of the Pd/ZnO catalytic systems.展开更多
Precise manipulation of the catalytic spin configuration and delineation of the relationship between spin related properties and oxidation pathways remain significant challenges in Fenton-like processes.Herein,encapsu...Precise manipulation of the catalytic spin configuration and delineation of the relationship between spin related properties and oxidation pathways remain significant challenges in Fenton-like processes.Herein,encapsulated cobalt nanoparticles and cobalt-nitrogen-doped carbon moieties,endowed with confinement effects and variations in shell curvature were constructed via straightforward pyrolysis strategies,inducing alterations in magnetic anisotropy,electronic energy levels and spin polarization.The enhanced spin polarization at cobalt sites leads to a reduction in crystal field splitting energy and an increase in electronic spin density.This phenomenon facilitated electron transfer from cobalt orbitals to pz orbitals of oxygen species within peroxymonosulfate molecules,thereby promoting the formation of high-valent cobalt species.The encapsulation effectively stabilized cobalt nanoparticles,mitigating their dissolution or deactivation during reactions,which in turn enhances stability and durability in continuous flow processes.The high-valent cobalt species within the shell exhibit increased exposure and generate localized high concentrations,thereby intensifying interactions with migrating pollutants and enabling efficient and selective oxidation of emerging compounds with elevated redox potentials.This work underscores the profound impact of confined encapsulation curvature and spin polarization characteristics of metal sites on catalytic oxidation pathways and performance,opening novel avenues for spin engineering in practical environmental catalysis.展开更多
Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to thei...Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to their small gyromagnetic ratios.A promising approach to achieving high nuclear spin polarization is transferring the polarization of electrons to nuclear spins.The nitrogen-vacancy(NV)center in diamond has emerged as a highly effective medium for this purpose,and various hyperpolarization protocols have been developed.Among these,the pulsed polarization(PulsePol)method has been extensively studied due to its robustness against static energy shifts of the electron spin.In this work,we present a novel polarization protocol and uncover a family of magic sequences for hyperpolarizing nuclear spins,with PulsePol emerging as a special case of our general approach.Notably,we demonstrate that some of these magic sequences exhibit significantly greater robustness compared to the PulsePol protocol in the presence of finite half𝜋pulse duration of the protocol,Rabi and detuning errors.This enhanced robustness positions our protocol as a more suitable candidate for hyper-polarizing nuclear spins species with large gyromagnetic ratios and also ensures better compatibility with high-efficiency readout techniques at high magnetic fields.Additionally,the generality of our protocol allows for its direct application to other solid-state quantum systems beyond the NV center.展开更多
Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease indu...Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.However,the effect of GLP-1 on intrinsic synuclein malfunction remains unclear.In this study,we investigated the effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism in SncaA53T transgenic mice and explored the underlying mechanisms.Our data showed that Lactococcus lactis MG1363-pMG36e-GLP-1 inhibited dopaminergic neuronal death,reduced pathological aggregation ofα-synuclein,and decreased movement disorders in SncaA53T transgenic mice.Furthermore,Lactococcus lactis MG1363-pMG36e-GLP-1 downregulated lipopolysaccharide-related inflammation,reduced cerebral activation of microglia and astrocytes,and promoted cell survival via the GLP-1 receptor/PI3K/Akt pathway in the substantia nigra.Additionally,Lactococcus lactis MG1363-pMG36e-GLP-1 decreased serum levels of pro-inflammatory molecules including lipopolysaccharide,lipopolysaccharide binding protein,interleukin-1β,and interleukin-6.Gut histopathology and western blotting further revealed that Lactococcus lactis MG1363-pMG36e-GLP-1 increased the expression of gut integrity-related proteins and reduced lipopolysaccharide-related inflammation by reversing gut dysbiosis in SncaA53T transgenic mice.Our findings showed that the beneficial effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism traits in SncaA53T transgenic mice is mediated by microglial polarization and the reversal of dysbiosis.Collectively,our findings suggest that Lactococcus lactis MG1363-pMG36e-GLP-1 is a promising therapeutic agent for the treatment of Parkinson’s disease.展开更多
This study unveils the evolution of two major early signals in the North Pacific atmosphere-ocean system that heralded abnormal high-pressure blockings and cold-vortex activities across Northeast China, based on an an...This study unveils the evolution of two major early signals in the North Pacific atmosphere-ocean system that heralded abnormal high-pressure blockings and cold-vortex activities across Northeast China, based on an analysis of the configurations of major modes including the polar vortex, the North Pacific Oscillation （NPO）, and SST in the preceding winter and spring and atmospheric low-frequency disturbances in Northeast China. We analyzed these aspects to understand the atmosphere ocean physical coupling processes characterized by the two early signals, and here we explain the possible mechanisms through which dipole circulation anomalies affect the summer low-temperature processes in Northeast China. We further analyzed the interdecadal variation background and associated physical processes of the two early signals.展开更多
The study conveys an idea to enhance the osseointegration of titanium implant (Ti) through modulating macrophages M2 polarization. The ?100 nm spherical mesoporous silica nanoparticles (MSN) that compromised of ~4-nm-...The study conveys an idea to enhance the osseointegration of titanium implant (Ti) through modulating macrophages M2 polarization. The ?100 nm spherical mesoporous silica nanoparticles (MSN) that compromised of ~4-nm-diameter nano? tunnels were synthesized by the conventional "sol-gel" method, into which the dexamethasone (DEX) was loaded (DEX@ MSN). The DEX@MSN could consistently release DEX and showed favorable cytocompatibility in RAW264.7 cells. The arginase-1 expression, a specific marker for macrophages M2 polarization, was also enhanced by DEX @ MSN treatment. Then, the Ti was pre-treated with anodization under 5 V to generate the titania nanotubes with ?30 nm diameter (NT-30) and the DEX @ MSN was introduced onto NT-30 surface via electrophoretic deposition, with the aid of chitosan. After optimizing the deposition parameters, the supernatants of RAW264.7 from the decorated implant surface could significantly promote the osteogenic differentiation of murine primary bone marrow mesenchymal stem cells. These findings demonstrate that delivery of DEX from implant surface can modulate the macrophages M2 polarization and result in favorable osteogenesis.展开更多
Cy5.5-MSA-G250 nanoparticles(CMGNPs)had been proved to have unique advantages for cancer treatment,including excellent photothermal performance,tumor cell-selective cytotoxicity,direct visualization,and good biocompat...Cy5.5-MSA-G250 nanoparticles(CMGNPs)had been proved to have unique advantages for cancer treatment,including excellent photothermal performance,tumor cell-selective cytotoxicity,direct visualization,and good biocompatibility.However,to cellular systems,the CMGNPs are considered as fo reign invaders,and the effect of CMGNPs on immunity system is still unknown.Therefore,more efforts are needed to understand the role of CMGNPs on the immunity system.In this study,we attempted to screen the pro-inflammatory responses on RAW264.7 macrophages after treated with the CMGNPs.In vitro experiments clearly showed that CMGNPs not only enhances phagocytosis capacity of RAW264.7 cells,but also promotes Ml polarization,associated with changes in cell morphology and increased expression of inflammatory cytokines.This ability to induce Ml polarization may be beneficial to CMGNPs to achieve better anticancer effects in clinical trials.Moreover,the observed Ml macrophages’ polarization triggered by CMGNPs can be abolished after adding TLR4 inhibitor,CLI095,suggesting that TLR4 is involved in CMGNP-induced inflammation.展开更多
Aiming at the problem of underwater polarized laser scattering caused by underwater suspended particles, the equivalent spherical particle Mie scattering theory simulation method is used to study the polarization char...Aiming at the problem of underwater polarized laser scattering caused by underwater suspended particles, the equivalent spherical particle Mie scattering theory simulation method is used to study the polarization characteristics of underwater scattered light. The relationship between underwater suspended particle characteristics and optical characteristics is analyzed, and the effects of particle size, polarization characteristics of incident light, and angle of incidence on the degree of polarization of forward and backward scattering light are studied. The results show that: When the incident light is natural light, the degree of polarization of scattered light is very low at the forward-scattering angle, which increases with the increase of the scattering angle, but changes frequently with the increase of the particle size. When the incident light is linearly polarized, the degree of linear polarization of the scattered light is related to the azimuth Angle. The degree of circular polarization is largely unaffected by particle size.展开更多
Based on a recently formulated unified theory of coherence and polarization, a method is described to study turbulence-induced changes in the polarization, the coherence and the spectrum of partially coherent electrom...Based on a recently formulated unified theory of coherence and polarization, a method is described to study turbulence-induced changes in the polarization, the coherence and the spectrum of partially coherent electromagnetic beams on propagation. The electromagnetic Gaussian Schell-model beam is taken as a typical example of partially coherent electromagnetic beams, and the closed-form expressions for the degree of polarization, the degree of coherence and the spectrum of electromagnetic Gaussian Schell-model beams propagating through atmospheric turbulence are derived in the quadratic approximation of Rytov＇s phase structure function. Some interesting results are obtained, which are illustrated by numerical examples and are explained in physics.展开更多
Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea ...Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea water （3.5% NaCl, mass fraction） was studied using Tafel plot and electrochemical impedance spectroscopy （EIS） techniques. The corrosion resistance of the investigated alloys with various Ni contents （0.5%？10%, mass fraction） was compared with that of Zn. The results show that the corrosion resistance of Zn？Ni alloys （except 0.5% Ni） is superior to that of Zn. The 10% Ni gives the highest corrosion resistance due to the formation ofγ-Zn3Ni withγ-ZnNi phases in the alloy. In the case of alloy I （0.5% Ni）, it exhibits a higher corrosion rate （less corrosion resistance） than Zn.展开更多
Nanocomposites comprising flexible polymers and high dielectric constant inorganic nanoparticles are considered to be one of the promising candidates for electrostatic capacitor dielectrics.However,the effect of inter...Nanocomposites comprising flexible polymers and high dielectric constant inorganic nanoparticles are considered to be one of the promising candidates for electrostatic capacitor dielectrics.However,the effect of interfacial property on electrical ene rgy storage of dielectric polymer nanocomposites is still not clear.Herein,the role of the polarity of the interfacial region is investigated.For this purpose,three polymers with different polarity,polymethyl methacrylate(PMMA),polyglycidyl methacrylate,and polymethylsulfonyl ethyl methacrylate(PMSEMA)are attached onto BaTi0_(3)(BT)na noparticle surface via surface-initiated reversible addition-fragmentation chain transfer polymerization.It is found that the polarity of shell polymers shows an apparent effect on the dielectric and energy storage of dielectric polymer nanocomposites.For example,PMSEMA@BT(shell polymer possesses the highest polarity)increases dielectric loss and decreases the breakdown strength of the nanocomposites,leading to lower ene rgy storage capability.However,PMMA@BT(shell polymer possesses the lowest polarity)can induce higher breakdown strength of the nanocomposites.As a result,the PMMA@BT nanocomposite exhibits the highest electrical energy sto rage capability among the three nanocomposites.This re search provides new insight into the design of core-shell nanofillers for dielectric energy storage applications.展开更多
Non-classical polarization properties of dark hollow beams propagating through non-Kolmogorov turbulence are studied. The analytic equation for the polarization degree of the quantization partially coherent dark hollo...Non-classical polarization properties of dark hollow beams propagating through non-Kolmogorov turbulence are studied. The analytic equation for the polarization degree of the quantization partially coherent dark hollow beams is obtained.It is found that the polarization fluctuations of the quantization partially coherent dark hollow beams are dependent on the turbulence factors and beam parameters with the detection photon numbers. Furthermore, an investigation of the changes in the on-axis propagation point and off-axis propagation point shows that the polarization degree of the quantization partially coherent dark hollow beams presents oscillation for a short propagation distance and gradually returns to zero for a sufficiently long distance.展开更多
Solid particles in Earth’s atmosphere,such as polystyrene beads,are an important factor affecting the processes of absorption and scattering of light in the atmosphere.These processes affect on the solar energy trans...Solid particles in Earth’s atmosphere,such as polystyrene beads,are an important factor affecting the processes of absorption and scattering of light in the atmosphere.These processes affect on the solar energy transfer in the Earth’s atmosphere,consequently they have influence on the regional and global climate changes and atmospheric visibility.In particular,great interest to study the scattering properties of small particles compared with wavelength,because of such particles experience low gravitational settlement and may have long time of life in the atmosphere.When scattering particle is much smaller than the wavelength of the scattered or absorbed light,this is the case of Rayleigh scattering.Scattering properties of these particles(such as intensity and the degree of linear polarization)at the Rayleigh scattering are simply derived from electromagnetic Maxwell’s equations.But when the particles are large enough to be comparable with the wavelength,the deviations from Rayleigh scattering law are observed.One of the clear manifestations of such deviations is the recently discovered quasi-Rayleigh polarization leap of monodisperse spherical particles.This quasi-Rayleigh polarization leap allows remote sensing of the sizes of distant particles,based on the spectral position of quasi-Rayleigh polarization leap at different phase angles of observation.In this paper,we studied the effect of the non-sphericity of a scattering polystyrene particle on the magnitude and position of the quasi-Rayleigh polarization leap.It is established that the non-sphericity shifts the position of the quasi-Rayleigh polarization leap shorter wavelengths.It is shown that for non-sphericity of particles makes the quasi-Rayleigh polarization leap becomes less pronounced.Moreover,it was found,that increasing of the phase angle and degree of non-sphericity shift the quasi-Rayleigh polarization leap position to shorter wavelength.However,in the case of not very elongated particles,the quasi-Rayleigh polarization leap is quite well manifested.Therefore,this method is suitable for remote sensing not only the size,but also the degree of non-sphericity of the scattering particles.A simple formula has been obtained for polystyrene beads that relates the degree of non-sphericity of a particle with the wavelength and phase angles at which the quasi-Rayleigh polarization leap is observed.展开更多
International cooperation is vital for the polar regions.China’s past polar cooperation has tended to focus on intergovernmental and bilateral mechanisms rather than regional cooperation.However,regional and subregio...International cooperation is vital for the polar regions.China’s past polar cooperation has tended to focus on intergovernmental and bilateral mechanisms rather than regional cooperation.However,regional and subregional cooperation is playing an increasing role in the polar regions with the rapid development of geopolitics and global climate change.Involvement in three subregional polar organizations—the Asian Forum for Polar Sciences(AFoPS),the Pacific Arctic Group(PAG),and the China-Nordic Arctic Research Center(CNARC)—in the last two decades reflects China’s improved skills and flexibility in participating in international polar cooperation and represents an exercise in the“win-win”principle under China’s Arctic policy.This paper presents a review of the development of polar subregional cooperation,examines China’s participation in three of subregional organizations and provides feasible suggestions for China’s future engagement with these organizations.展开更多
The hollow porous structure with exceptional interfacial effect and customizable internal environment shows significant potential for application as electromagnetic shielding and absorption materials.However,designing...The hollow porous structure with exceptional interfacial effect and customizable internal environment shows significant potential for application as electromagnetic shielding and absorption materials.However,designing hollow porous electromagnetic absorbers with both desirable impedance matching and high loss capability remains a challenge.Herein,3D hollow porous electromagnetic microspheres were constructed by assembling 0D Co magnetic nanoparticles,1D carbon nanotubes,and 2D carbon nanosheets.Due to the sufficient sites for Co^(2+)riveting,the high loading of magnetic carbon nanotubes(CoNC)and porous carbon spheres formed high-density interfaces,enhancing the interfacial polarization.Furthermore,high-density CoNC were grown in situ on the hollow porous carbon(HPC)microsphere,forming a highly dispersed 3D magnetic network that inhibited the aggregation of magnetic nanoparticles and enhanced magnetic coupling.Therefore,the asprepared CoNC/HPC microspheres exhibited excellent microwave absorption(MA)performance,with a minimum reflection loss of-33.2 dB and an effective bandwidth of 5.5 GHz at a thickness of only 1.8 mm.The interfacial polarization mechanism for enhanced MA performance was demonstrated by electron holography and density functional theory calculations.Magnetic holography and micromagnetic simulations also revealed magnetic confinement and coupling mechanism.This work provides a new approach for designing electromagnetic absorbers with optimized impedance matching and loss capability.展开更多
This paper presents a modified secure direct communication protocol by using the blind polarization bases and particles＇ random transmitting order. In our protocol, a sender （Alice） encodes secret messages by rotat...This paper presents a modified secure direct communication protocol by using the blind polarization bases and particles＇ random transmitting order. In our protocol, a sender （Alice） encodes secret messages by rotating a random polarization angle of particle and then the receiver （Bob） sends back these particles as a random sequence. This ensures the security of communication.展开更多
We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission....We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission. We describe the principle by distributing n-qubit Greenberge-Horne--Zeilinger state and n-qubit W state. Our scheme can be used to distribute arbitrary n-qUbit entangled states to n distant locations. The remote parties can obtain maximally entangled states deterministically on the polarization of photons. Only passive linear optics are employed in our setup, which makes our scheme more feasible and efficient for practical application in long distance quantum communication.展开更多
Based on vectorial Debye theory, the focusing properties of partially polarized vortex beam by high numerical aperture Fresnel zone plate are investigated. The effects of the numerical apertures of and the phase diffe...Based on vectorial Debye theory, the focusing properties of partially polarized vortex beam by high numerical aperture Fresnel zone plate are investigated. The effects of the numerical apertures of and the phase difference of binary phase Fresnel zone plates, the topological charge of vortex beam and the degree of polarization of incident beam on the intensity distribution and degree of coherence in the focal plane are investigated in detail. It is shown that elliptical light spots and the flat top beam can be obtained by selecting certain parameters. Studies of degree of coherence reveal that the degree of coherence between x and y components of the electric field, which is zero in the source plane, is improved in the focal plane for vortex beam, but it is hardly changed for the nonvortex beam. It is also proved that any two of the three electric field components Ex, Ey and Ez are completely coherent everywhere in the focal region if the incident light beam is linearly polarized.展开更多
文摘The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological data of these particles has became a key focus in wear debris analysis.Herein,we develop a novel multi-view polarization-sensitive optical coherence tomography(PS-OCT)method to achieve accurate 3D morphology detection and reconstruction of aero-engine lubricant wear particles,effectively resolving occlusion-induced information loss while enabling material-specific characterization.The particle morphology is captured by multi-view imaging,followed by filtering,sharpening,and contour recognition.The method integrates advanced registration algorithms with Poisson reconstruction to generate high-precision 3D models.This approach not only provides accurate 3D morphological reconstruction but also mitigates information loss caused by particle occlusion,ensuring model completeness.Furthermore,by collecting polarization characteristics of typical metals and their oxides in aero-engine lubricants,this work comprehensively characterizes and comparatively analyzes particle polarization properties using Stokes vectors,polarization uniformity,and cumulative phase retardation,and obtains a three-dimensional model containing polarization information.Ultimately,the proposed method enables multidimensional information acquisition for the reliable identification of abrasive particle types.
基金supported by the National Natural Science Foundation of China(No.22172152,No.21872130)the National Key R&D Program of China(No.2021YFA1502801).
文摘Researching the dispersion as well as the stability of metals on the oxide surfaces is essentially important for understanding the interaction mecha-nisms at the metal/oxide interfaces and thus optimizing the activities of the heterogeneous catalysts.Here in this work,we have investigated the growth behavior of Pd particles on the polar surfaces of ZnO with scanning tunneling microscopy(STM).By systematically varying the coverages as well as the annealing temperatures,we found that at room temperature Pd tends to form three-dimensional(3D)round particles on the ZnO(000)surface but grow into monolayer two-dimensional(2D)hexagonal islands on the ZnO(0001)surface.During annealing processes,the Pd particles on ZnO(000)aggregate gently while maintaining the 3D morphology in the mild temperature range but then quickly transform in-to tall hexagonal islands at elevated temperatures.In contrast,the segregation of Pd islands on ZnO(0001)occurs gradually along with the temperature rising without changing the 2D morphology.These results directly reflect the different interaction strengths of Pd on the dis-tinct ZnO polar surfaces.They also provide important input for understanding the facet-de-pendent catalytic mechanisms of the Pd/ZnO catalytic systems.
文摘Precise manipulation of the catalytic spin configuration and delineation of the relationship between spin related properties and oxidation pathways remain significant challenges in Fenton-like processes.Herein,encapsulated cobalt nanoparticles and cobalt-nitrogen-doped carbon moieties,endowed with confinement effects and variations in shell curvature were constructed via straightforward pyrolysis strategies,inducing alterations in magnetic anisotropy,electronic energy levels and spin polarization.The enhanced spin polarization at cobalt sites leads to a reduction in crystal field splitting energy and an increase in electronic spin density.This phenomenon facilitated electron transfer from cobalt orbitals to pz orbitals of oxygen species within peroxymonosulfate molecules,thereby promoting the formation of high-valent cobalt species.The encapsulation effectively stabilized cobalt nanoparticles,mitigating their dissolution or deactivation during reactions,which in turn enhances stability and durability in continuous flow processes.The high-valent cobalt species within the shell exhibit increased exposure and generate localized high concentrations,thereby intensifying interactions with migrating pollutants and enabling efficient and selective oxidation of emerging compounds with elevated redox potentials.This work underscores the profound impact of confined encapsulation curvature and spin polarization characteristics of metal sites on catalytic oxidation pathways and performance,opening novel avenues for spin engineering in practical environmental catalysis.
基金supported by the National Natural Science Foundation of China (Grant Nos.12475012,62461160263 for P.W.,and 62276171 for H.L.)Quantum Science and Technology-National Science and Technology Major Project of China (Project No.2023ZD0300600 for P.W.)+3 种基金Guangdong Provincial Quantum Science Strategic Initiative (Grant Nos.GDZX240-3009 and GDZX2303005 for P.W.)Guangdong Basic and Applied Basic Research Foundation (Grant No.2024-A1515011938 for H.L.)Shenzhen Fundamental ResearchGeneral Project (Grant No.JCYJ20240813141503005 for H.L.)the Talents Introduction Foundation of Beijing Normal University (Grant No.310432106 for P.W.)。
文摘Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to their small gyromagnetic ratios.A promising approach to achieving high nuclear spin polarization is transferring the polarization of electrons to nuclear spins.The nitrogen-vacancy(NV)center in diamond has emerged as a highly effective medium for this purpose,and various hyperpolarization protocols have been developed.Among these,the pulsed polarization(PulsePol)method has been extensively studied due to its robustness against static energy shifts of the electron spin.In this work,we present a novel polarization protocol and uncover a family of magic sequences for hyperpolarizing nuclear spins,with PulsePol emerging as a special case of our general approach.Notably,we demonstrate that some of these magic sequences exhibit significantly greater robustness compared to the PulsePol protocol in the presence of finite half𝜋pulse duration of the protocol,Rabi and detuning errors.This enhanced robustness positions our protocol as a more suitable candidate for hyper-polarizing nuclear spins species with large gyromagnetic ratios and also ensures better compatibility with high-efficiency readout techniques at high magnetic fields.Additionally,the generality of our protocol allows for its direct application to other solid-state quantum systems beyond the NV center.
基金supported by grants from the Jiangxi Provincial Natural Science Foundation,No.20242BAB26134(to XF)the National Natural Science Foundation of China,Nos.82060638(to TC),82060222(to XF),82460237(to XF)+1 种基金the Major Disciplines of Academic and Technical Leaders Project of Jiangxi Province,Nos.20194BCJ22032(to TC),20213BCJL22049(to XF)Science and Technology Plan of Jiangxi Health Planning Committee,No.202210390(to XF).
文摘Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.However,the effect of GLP-1 on intrinsic synuclein malfunction remains unclear.In this study,we investigated the effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism in SncaA53T transgenic mice and explored the underlying mechanisms.Our data showed that Lactococcus lactis MG1363-pMG36e-GLP-1 inhibited dopaminergic neuronal death,reduced pathological aggregation ofα-synuclein,and decreased movement disorders in SncaA53T transgenic mice.Furthermore,Lactococcus lactis MG1363-pMG36e-GLP-1 downregulated lipopolysaccharide-related inflammation,reduced cerebral activation of microglia and astrocytes,and promoted cell survival via the GLP-1 receptor/PI3K/Akt pathway in the substantia nigra.Additionally,Lactococcus lactis MG1363-pMG36e-GLP-1 decreased serum levels of pro-inflammatory molecules including lipopolysaccharide,lipopolysaccharide binding protein,interleukin-1β,and interleukin-6.Gut histopathology and western blotting further revealed that Lactococcus lactis MG1363-pMG36e-GLP-1 increased the expression of gut integrity-related proteins and reduced lipopolysaccharide-related inflammation by reversing gut dysbiosis in SncaA53T transgenic mice.Our findings showed that the beneficial effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism traits in SncaA53T transgenic mice is mediated by microglial polarization and the reversal of dysbiosis.Collectively,our findings suggest that Lactococcus lactis MG1363-pMG36e-GLP-1 is a promising therapeutic agent for the treatment of Parkinson’s disease.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41175083 and 41275096)the Special Fund for Meteorological Scientific Research in the Public Interest (Grant Nos. GYHY201006020,GYHY201106016,and GYHY201106015)
文摘This study unveils the evolution of two major early signals in the North Pacific atmosphere-ocean system that heralded abnormal high-pressure blockings and cold-vortex activities across Northeast China, based on an analysis of the configurations of major modes including the polar vortex, the North Pacific Oscillation （NPO）, and SST in the preceding winter and spring and atmospheric low-frequency disturbances in Northeast China. We analyzed these aspects to understand the atmosphere ocean physical coupling processes characterized by the two early signals, and here we explain the possible mechanisms through which dipole circulation anomalies affect the summer low-temperature processes in Northeast China. We further analyzed the interdecadal variation background and associated physical processes of the two early signals.
基金supported by the National Natural Science Foundation of China (Nos. 31800790, 81530051 and 31670966)
文摘The study conveys an idea to enhance the osseointegration of titanium implant (Ti) through modulating macrophages M2 polarization. The ?100 nm spherical mesoporous silica nanoparticles (MSN) that compromised of ~4-nm-diameter nano? tunnels were synthesized by the conventional "sol-gel" method, into which the dexamethasone (DEX) was loaded (DEX@ MSN). The DEX@MSN could consistently release DEX and showed favorable cytocompatibility in RAW264.7 cells. The arginase-1 expression, a specific marker for macrophages M2 polarization, was also enhanced by DEX @ MSN treatment. Then, the Ti was pre-treated with anodization under 5 V to generate the titania nanotubes with ?30 nm diameter (NT-30) and the DEX @ MSN was introduced onto NT-30 surface via electrophoretic deposition, with the aid of chitosan. After optimizing the deposition parameters, the supernatants of RAW264.7 from the decorated implant surface could significantly promote the osteogenic differentiation of murine primary bone marrow mesenchymal stem cells. These findings demonstrate that delivery of DEX from implant surface can modulate the macrophages M2 polarization and result in favorable osteogenesis.
基金financially supported by the National Natural Science Foundation of China (Nos. 81660592, 81660301 and 81860037)the Key New and High-Tech Project of the Department of Science and Technology of Hainan Province (No. ZDYF2016023)
文摘Cy5.5-MSA-G250 nanoparticles(CMGNPs)had been proved to have unique advantages for cancer treatment,including excellent photothermal performance,tumor cell-selective cytotoxicity,direct visualization,and good biocompatibility.However,to cellular systems,the CMGNPs are considered as fo reign invaders,and the effect of CMGNPs on immunity system is still unknown.Therefore,more efforts are needed to understand the role of CMGNPs on the immunity system.In this study,we attempted to screen the pro-inflammatory responses on RAW264.7 macrophages after treated with the CMGNPs.In vitro experiments clearly showed that CMGNPs not only enhances phagocytosis capacity of RAW264.7 cells,but also promotes Ml polarization,associated with changes in cell morphology and increased expression of inflammatory cytokines.This ability to induce Ml polarization may be beneficial to CMGNPs to achieve better anticancer effects in clinical trials.Moreover,the observed Ml macrophages’ polarization triggered by CMGNPs can be abolished after adding TLR4 inhibitor,CLI095,suggesting that TLR4 is involved in CMGNP-induced inflammation.
基金supported by the National Natural Science Foundation of China(No.61404362)。
文摘Aiming at the problem of underwater polarized laser scattering caused by underwater suspended particles, the equivalent spherical particle Mie scattering theory simulation method is used to study the polarization characteristics of underwater scattered light. The relationship between underwater suspended particle characteristics and optical characteristics is analyzed, and the effects of particle size, polarization characteristics of incident light, and angle of incidence on the degree of polarization of forward and backward scattering light are studied. The results show that: When the incident light is natural light, the degree of polarization of scattered light is very low at the forward-scattering angle, which increases with the increase of the scattering angle, but changes frequently with the increase of the particle size. When the incident light is linearly polarized, the degree of linear polarization of the scattered light is related to the azimuth Angle. The degree of circular polarization is largely unaffected by particle size.
基金supported by the National Natural Science Foundation of China (Grant No. 60778048)
文摘Based on a recently formulated unified theory of coherence and polarization, a method is described to study turbulence-induced changes in the polarization, the coherence and the spectrum of partially coherent electromagnetic beams on propagation. The electromagnetic Gaussian Schell-model beam is taken as a typical example of partially coherent electromagnetic beams, and the closed-form expressions for the degree of polarization, the degree of coherence and the spectrum of electromagnetic Gaussian Schell-model beams propagating through atmospheric turbulence are derived in the quadratic approximation of Rytov＇s phase structure function. Some interesting results are obtained, which are illustrated by numerical examples and are explained in physics.
文摘Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea water （3.5% NaCl, mass fraction） was studied using Tafel plot and electrochemical impedance spectroscopy （EIS） techniques. The corrosion resistance of the investigated alloys with various Ni contents （0.5%？10%, mass fraction） was compared with that of Zn. The results show that the corrosion resistance of Zn？Ni alloys （except 0.5% Ni） is superior to that of Zn. The 10% Ni gives the highest corrosion resistance due to the formation ofγ-Zn3Ni withγ-ZnNi phases in the alloy. In the case of alloy I （0.5% Ni）, it exhibits a higher corrosion rate （less corrosion resistance） than Zn.
基金The financial support from National Natural Science Foundation of China(No.51877132)。
文摘Nanocomposites comprising flexible polymers and high dielectric constant inorganic nanoparticles are considered to be one of the promising candidates for electrostatic capacitor dielectrics.However,the effect of interfacial property on electrical ene rgy storage of dielectric polymer nanocomposites is still not clear.Herein,the role of the polarity of the interfacial region is investigated.For this purpose,three polymers with different polarity,polymethyl methacrylate(PMMA),polyglycidyl methacrylate,and polymethylsulfonyl ethyl methacrylate(PMSEMA)are attached onto BaTi0_(3)(BT)na noparticle surface via surface-initiated reversible addition-fragmentation chain transfer polymerization.It is found that the polarity of shell polymers shows an apparent effect on the dielectric and energy storage of dielectric polymer nanocomposites.For example,PMSEMA@BT(shell polymer possesses the highest polarity)increases dielectric loss and decreases the breakdown strength of the nanocomposites,leading to lower ene rgy storage capability.However,PMMA@BT(shell polymer possesses the lowest polarity)can induce higher breakdown strength of the nanocomposites.As a result,the PMMA@BT nanocomposite exhibits the highest electrical energy sto rage capability among the three nanocomposites.This re search provides new insight into the design of core-shell nanofillers for dielectric energy storage applications.
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.61405205)
文摘Non-classical polarization properties of dark hollow beams propagating through non-Kolmogorov turbulence are studied. The analytic equation for the polarization degree of the quantization partially coherent dark hollow beams is obtained.It is found that the polarization fluctuations of the quantization partially coherent dark hollow beams are dependent on the turbulence factors and beam parameters with the detection photon numbers. Furthermore, an investigation of the changes in the on-axis propagation point and off-axis propagation point shows that the polarization degree of the quantization partially coherent dark hollow beams presents oscillation for a short propagation distance and gradually returns to zero for a sufficiently long distance.
文摘Solid particles in Earth’s atmosphere,such as polystyrene beads,are an important factor affecting the processes of absorption and scattering of light in the atmosphere.These processes affect on the solar energy transfer in the Earth’s atmosphere,consequently they have influence on the regional and global climate changes and atmospheric visibility.In particular,great interest to study the scattering properties of small particles compared with wavelength,because of such particles experience low gravitational settlement and may have long time of life in the atmosphere.When scattering particle is much smaller than the wavelength of the scattered or absorbed light,this is the case of Rayleigh scattering.Scattering properties of these particles(such as intensity and the degree of linear polarization)at the Rayleigh scattering are simply derived from electromagnetic Maxwell’s equations.But when the particles are large enough to be comparable with the wavelength,the deviations from Rayleigh scattering law are observed.One of the clear manifestations of such deviations is the recently discovered quasi-Rayleigh polarization leap of monodisperse spherical particles.This quasi-Rayleigh polarization leap allows remote sensing of the sizes of distant particles,based on the spectral position of quasi-Rayleigh polarization leap at different phase angles of observation.In this paper,we studied the effect of the non-sphericity of a scattering polystyrene particle on the magnitude and position of the quasi-Rayleigh polarization leap.It is established that the non-sphericity shifts the position of the quasi-Rayleigh polarization leap shorter wavelengths.It is shown that for non-sphericity of particles makes the quasi-Rayleigh polarization leap becomes less pronounced.Moreover,it was found,that increasing of the phase angle and degree of non-sphericity shift the quasi-Rayleigh polarization leap position to shorter wavelength.However,in the case of not very elongated particles,the quasi-Rayleigh polarization leap is quite well manifested.Therefore,this method is suitable for remote sensing not only the size,but also the degree of non-sphericity of the scattering particles.A simple formula has been obtained for polystyrene beads that relates the degree of non-sphericity of a particle with the wavelength and phase angles at which the quasi-Rayleigh polarization leap is observed.
文摘International cooperation is vital for the polar regions.China’s past polar cooperation has tended to focus on intergovernmental and bilateral mechanisms rather than regional cooperation.However,regional and subregional cooperation is playing an increasing role in the polar regions with the rapid development of geopolitics and global climate change.Involvement in three subregional polar organizations—the Asian Forum for Polar Sciences(AFoPS),the Pacific Arctic Group(PAG),and the China-Nordic Arctic Research Center(CNARC)—in the last two decades reflects China’s improved skills and flexibility in participating in international polar cooperation and represents an exercise in the“win-win”principle under China’s Arctic policy.This paper presents a review of the development of polar subregional cooperation,examines China’s participation in three of subregional organizations and provides feasible suggestions for China’s future engagement with these organizations.
基金supported by the National Natural Science Foundation of China(Nos.52231007,51725101,11727807)the Ministry of Science and Technology of China(Nos.2021YFA1200600 and 2018YFA0209102).
文摘The hollow porous structure with exceptional interfacial effect and customizable internal environment shows significant potential for application as electromagnetic shielding and absorption materials.However,designing hollow porous electromagnetic absorbers with both desirable impedance matching and high loss capability remains a challenge.Herein,3D hollow porous electromagnetic microspheres were constructed by assembling 0D Co magnetic nanoparticles,1D carbon nanotubes,and 2D carbon nanosheets.Due to the sufficient sites for Co^(2+)riveting,the high loading of magnetic carbon nanotubes(CoNC)and porous carbon spheres formed high-density interfaces,enhancing the interfacial polarization.Furthermore,high-density CoNC were grown in situ on the hollow porous carbon(HPC)microsphere,forming a highly dispersed 3D magnetic network that inhibited the aggregation of magnetic nanoparticles and enhanced magnetic coupling.Therefore,the asprepared CoNC/HPC microspheres exhibited excellent microwave absorption(MA)performance,with a minimum reflection loss of-33.2 dB and an effective bandwidth of 5.5 GHz at a thickness of only 1.8 mm.The interfacial polarization mechanism for enhanced MA performance was demonstrated by electron holography and density functional theory calculations.Magnetic holography and micromagnetic simulations also revealed magnetic confinement and coupling mechanism.This work provides a new approach for designing electromagnetic absorbers with optimized impedance matching and loss capability.
基金Project supported by the National Natural Science Foundation of China （Grant No 60667001）.
文摘This paper presents a modified secure direct communication protocol by using the blind polarization bases and particles＇ random transmitting order. In our protocol, a sender （Alice） encodes secret messages by rotating a random polarization angle of particle and then the receiver （Bob） sends back these particles as a random sequence. This ensures the security of communication.
基金Supported by the National Natural Science Foundation of China under Grant No.11004258Fundamental Research Funds for the Central Universities under Grant No.CQDXWL-2012-014
文摘We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission. We describe the principle by distributing n-qubit Greenberge-Horne--Zeilinger state and n-qubit W state. Our scheme can be used to distribute arbitrary n-qUbit entangled states to n distant locations. The remote parties can obtain maximally entangled states deterministically on the polarization of photons. Only passive linear optics are employed in our setup, which makes our scheme more feasible and efficient for practical application in long distance quantum communication.
基金supported by the National Natural Science Foundation of China(Grant No.60977068)the Open Research Fund of Key Laboratory of Atmospheric Composition and Optical Radiation,Chinese Academy of Sciences(Grant No.SKLST200912)the Overseas Chinese Affairs Office of the State Council(Grant No.lOQZROl)
文摘Based on vectorial Debye theory, the focusing properties of partially polarized vortex beam by high numerical aperture Fresnel zone plate are investigated. The effects of the numerical apertures of and the phase difference of binary phase Fresnel zone plates, the topological charge of vortex beam and the degree of polarization of incident beam on the intensity distribution and degree of coherence in the focal plane are investigated in detail. It is shown that elliptical light spots and the flat top beam can be obtained by selecting certain parameters. Studies of degree of coherence reveal that the degree of coherence between x and y components of the electric field, which is zero in the source plane, is improved in the focal plane for vortex beam, but it is hardly changed for the nonvortex beam. It is also proved that any two of the three electric field components Ex, Ey and Ez are completely coherent everywhere in the focal region if the incident light beam is linearly polarized.
