Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxi...Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was conducted.Full-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.展开更多
The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean cu...The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite data.Mooring observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 mooring.In the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal winter.In addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency currents.The upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 d.Further analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave packets.Moreover,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation period.In addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.展开更多
Nonlinear materials have gained wide interest as saturable absorbers and pulse compression for pulsed laser applications due to their unique optical properties.This work investigates the third-order nonlinear phenomen...Nonlinear materials have gained wide interest as saturable absorbers and pulse compression for pulsed laser applications due to their unique optical properties.This work investigates the third-order nonlinear phenomenon of tungsten trioxide(WO_(3))thin films.The giant nonlinear absorption and nonlinear refractive index of WO_(3)thin films were characterized by Z-scan method at 800 nm.We experimentally observed the giant saturable absorption(SA)and nonlinear refractive index of WO_(3)thin films prepared by the seedless layer hydrothermal method,with SA coefficient being as high as-2.59×105cm·GW^(-1).The SA coefficient is at least one order of magnitude larger than those of the conventional semiconductors.The nonlinear refractive index n_(2)of WO_(3)film has been observed for the first time in recent studies and the corresponding coefficient can be up to 1.793 cm^(2)·GW^(-1).The large third-order nonlinear optical(NLO)response enables WO_(3)thin films to be promising candidates for optoelectronic and photonic applications in the near-infrared domain.展开更多
Deep in-situ rock mechanics considers the influence of the in-situ environment on mechanical properties,differentiating it from traditional rock mechanics.To investigate the effect of in-situ stress,pore pressure pres...Deep in-situ rock mechanics considers the influence of the in-situ environment on mechanical properties,differentiating it from traditional rock mechanics.To investigate the effect of in-situ stress,pore pressure preserved environment on the mechanical difference of sandstone,four tests are numerically modeled by COMSOL:conventional triaxial test,conventional pore pressure test,in-situ stress restoration and reconstruction test,and in-situ pore pressure-preserved test(not yet realized in the laboratory).The in-situ stress restoration parameter is introduced to characterize the recovery effect of in-situ stress on elastic modulus and heterogeneous distribution of sandstone at different depths.A random function and nonuniform pore pressure coefficient are employed to describe the non-uniform distribution of pore pressure in the in-situ environment.Numerical results are compared with existing experimental data to validate the models and calibrate the numerical parameters.By extracting mechanical parameters from numerical cores,the stress-strain curves of the four tests under different depths,in-situ stress and pore pressure are compared.The influence of non-uniform pore pressure coefficient and depth on the peak strength of sandstone is analyzed.The results show a strong linear relationship between the in-situ stress restoration parameter and depth,effectively characterizing the enhanced effect of stress restoration and reconstruction methods on the elastic modulus of conventional cores at different depths.The in-situ pore pressurepreserved test exhibits lower peak stress and peak strain compared to the other three tests,and sandstone subjected to non-uniform pore pressure is more prone to plastic damage and failure.Moreover,the influence of non-uniform pore pressure on peak strength gradually diminished with increasing depth.展开更多
In order to meet the clinical requirements of spine surgery,this paper proposed the exploratory research of computer-aided design and selective laser melting(SLM)fabrication of a bionic porous titanium spine implant.T...In order to meet the clinical requirements of spine surgery,this paper proposed the exploratory research of computer-aided design and selective laser melting(SLM)fabrication of a bionic porous titanium spine implant.The structural design of the spinal implant is based on CT scanning data to ensure correct matching,and the mechanical properties of the implant are verified by simulation analysis and laser selective melting experiment.The surface roughness of the spinal implant manufactured by SLM without post-processing is Ra 15μm,and the implant is precisely jointed with the photosensitive resin model of the upper and lower spine.The surface micro-hardness of the implant is HV 373,tensile strengthσ_(b)=1238.7 MPa,yield strengthσ_(0.2)=1043.9 MPa,the elongation is 6.43%,and the compressive strength of porous structure under 84.60%porosity is 184.09 MPa,which can meet the requirements of the reconstruction of stable spines.Compared with the traditional implant and intervertebral fusion cage,the bionic porous spinal implant has the advantages of accurate fit,porous bionic structure and recovery of patients,and the ion release experiment proved that implants manufactured by SLM are more suitable for clinical application after certain treatments.The elastic modulus of the sample is improved after heat treatment,mainly because the microstructure of the sample changes fromα’phase toα+βdual-phase after heat treatment.In addition,the design of high-quality bionic porous spinal implants still needs to be optimized for the actual needs of doctors.展开更多
Conjugated microporous polymer(CMP)is an emerging organic semiconductor withπ-conjugated skeletons,and the bandgap of CMP can be flexibly modulated to harvest visible light.Based on the diversity and adjustability of...Conjugated microporous polymer(CMP)is an emerging organic semiconductor withπ-conjugated skeletons,and the bandgap of CMP can be flexibly modulated to harvest visible light.Based on the diversity and adjustability of monomers in CMP,we designed and synthesized donor-accepter(D-A)type BTNCMP through Sonogashira-Hagihara cross-coupling polymerization,further in-situ constructing series of inorganic/organic Z-scheme BW/BTN-n composite in the presence of Bi_(2)WO_(6).After optimization,the tetracycline hydrochloride(C0=10 mg·L^(-1))degradation efficiency reached 84%with BW/BTN-2 as catalyst in 90 min under visible light irradiation,the apparent rate constant k1 is 0.017 min^(-1),which is 1.7 and 5.7 times higher than bare Bi_(2)WO_(6) and BTN-CMP.X-ray photoelectron spectra and UV-Vis diffuse spectra showed that the enhanced photocatalytic activity originated from the tight heterojunction between Bi_(2)WO_(6) and BTN-CMP,which can extend the light absorption range and facilitate the separation and transport of photogenerated charges in the interface of heterojunction.The active species trapping experiments and electron spin resonance technique revealed that h+was the dominant active species during the photodegradation process of tetracycline hydrochloride(TCH).The present study demonstrated the feasibility to construct inorganic/organic composite for the photocatalytic degradation of environmental pollutants.展开更多
As one of the most promising alternative fuels,hydrogen is expected with high hopes.The electrolysis of water is regarded as the cleanest and most efficient method of hydrogen production.Molybdenum disulfide(MoS_(2))i...As one of the most promising alternative fuels,hydrogen is expected with high hopes.The electrolysis of water is regarded as the cleanest and most efficient method of hydrogen production.Molybdenum disulfide(MoS_(2))is deemed as one of the most promising alternatives HER catalysts owing to its high catalytic activity and low cost.Its continuous production and efficient preparation become the key problems in future industrial production.In this work,we first developed a continuous micro-reaction approach with high heat and mass transfer rates to synthesize few-layer MoS_(2)nanoplates with abundant active sites.The defective MoS_(2)ultrathin nanoplates exhibit excellent HER performance with an overpotential of 260 m V at a current density of 10 m A cm^(-2),small Tafel slope(53.6 m V dec^(-1))and prominent durability,which are comparable to most reported MoS_(2)based catalysts.Considering the existence of continuous devices,it's suitable for the synthesis of MoS_(2)as highperformance electrocatalysts for the industrial water electrolysis.The novel preparation method may open up a new way to synthesize all two-dimension materials toward HER.展开更多
The Kitaev spin liquid(KSL) system has attracted tremendous attention in recent years because of its fundamental significance in condensed matter physics and promising applications in fault-tolerant topological quantu...The Kitaev spin liquid(KSL) system has attracted tremendous attention in recent years because of its fundamental significance in condensed matter physics and promising applications in fault-tolerant topological quantum computation.Material realization of such a system remains a major challenge in the field due to the unusual configuration of anisotropic spin interactions,though great effort has been made before.Here we reveal that rare-earth chalcohalides REChX(RE=rare earth;Ch=O,S,Se,Te;X=F,Cl,Br,I) can serve as a family of KSL candidates.Most family members have the typical SmSI-type structure with a high symmetry of R3m,and rare-earth magnetic ions form an undistorted honeycomb lattice.The strong spin-orbit coupling of 4f electrons intrinsically offers anisotropic spin interactions as required by the Kitaev model.We have grown the crystals of YbOCl and synthesized the polycrystals of SmSI,ErOF,HoOF and DyOF,and made careful structural characterizations.We carry out magnetic and heat capacity measurements down to 1.8 K and find no obvious magnetic transition in all the samples but DyOF.The van der Waals interlayer coupling highlights the true two-dimensionality of the family which is vital for the exact realization of Abelian/non-Abelian anyons,and the graphene-like feature will be a prominent advantage for developing miniaturized devices.The family is expected to act as an inspiring material platform for the exploration of KSL physics.展开更多
Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a la...Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.展开更多
Amorphous iridium oxides(IrO_(x))are highly active for oxygen evolution reaction(OER)in acid media;however,it is generally unstable compared with commercial IrO_(2).Recently,many non-noble metal-iridium mixed oxides a...Amorphous iridium oxides(IrO_(x))are highly active for oxygen evolution reaction(OER)in acid media;however,it is generally unstable compared with commercial IrO_(2).Recently,many non-noble metal-iridium mixed oxides are prepared for catalyzing OER efficiently.Herein,we report a cubic fluorite-type praseodymium iridium oxide with the surface of IrO_(x)(IrO_(x)/Pr_(3)IrO_(7))that shows the improved activity and stability in 0.1 mol L^(-1) HClO_(4) solution,characterized by an overpotential of 305 mV at the benchmark of 10 mA cm^(-2) and a small Tafel slope of 37 mV dec^(-1),indicating a fast reaction kinetics and a competitive activity compared with the benchmark IrO_(2) and most reported electrocatalysts.The initial potential increases by less than 0.07 V after continuous OER testing over 60,000 s.In contrast,IrO_(2) becomes nearly inactive for the OER within 20,000 s.Density functional theory calculations uncover that the optimal energy level path follows lattice oxygen mechanism(LOM).This work enlarges the family of the IrO_(x)-type OER electrocatalyst in acid media.展开更多
Kuo-Hua Sun(孙国华,1902-1958,courtesy name—Xiao Meng)(Fig.1)was a Chinese psychologist mainly engaged in Physiological Psychology and Child Psychology.Kuo-Hua Sun was born on March 6th,1902,in Weixian,Shandong provin...Kuo-Hua Sun(孙国华,1902-1958,courtesy name—Xiao Meng)(Fig.1)was a Chinese psychologist mainly engaged in Physiological Psychology and Child Psychology.Kuo-Hua Sun was born on March 6th,1902,in Weixian,Shandong province.He studied in Tsinghua School from 1914 to 1923.At the same year,Sun attended the education school of Ohio State University,and then received a Bachelor of Psychology(1928)and a Doctor of Philosophy(1929)from Ohio State University.During this period,Sun studied in the Department of Physiology at Chicago University(1925-1926)(Fig.2).展开更多
The physical properties of most 2D materials are highly dependent on the nature of their interlayer interaction.In-depth studies of the interlayer interaction are beneficial to the understanding of the physical proper...The physical properties of most 2D materials are highly dependent on the nature of their interlayer interaction.In-depth studies of the interlayer interaction are beneficial to the understanding of the physical properties of 2D materials and permit the development of related devices.Layered magnetic NiPS_(3)has unique magnetic and electronic properties.The electronic band structure and corresponding magnetic state of NiPS_(3)are expected to be sensitive to the interlayer interaction,which can be tuned by external pressure.Here,we report an insulator-metal transition accompanied by the collapse of magnetic order during the 2D-3D structural crossover induced by hydrostatic pressure.A two-stage phase transition from a monoclinic(C2/m)to a trigonal(P31m)lattice is identified via ab initio simulations and confirmed via high-pressure X-ray diffraction and Raman scattering;this transition corresponds to a layer-by-layer slip mechanism along the a-axis.Temperature-dependent resistance measurements and room temperature infrared spectroscopy under different pressures demonstrate that the insulator-metal transition and the collapse of the magnetic order occur at~20 GPa,which is confirmed by low-temperature Raman scattering measurements and theoretical calculations.These results establish a strong correlation between the structural change,electric transport,and magnetic phase transition and expand our understanding of layered magnetic materials.Moreover,the structural transition caused by the interlayer displacement has significance for designing similar devices at ambient pressure.展开更多
The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.D...The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.Details of the laboratory construction,virtual autopsy process,case analysis,research and development,establishment of standards,application in teaching,and other aspects of the center are summarized in this paper.In addition,we expound the prospective and practical significance of the virtual anatomy laboratory.Based on computed tomography and magnetic resonance detection methods,the prospective applications of virtual anatomy in forensic identification are explored through the analyses of two real-life cases.Using information from traditional anatomy as the gold standard,this study expanded on and explored the application technology and scenarios of virtual anatomy in imaging,clinical diagnosis,and equipment manufacturing,among other fields.The four cooperating units have their strengths and will yield valuable scientific research results and social benefits.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52121003,51827901 and 52204110)China Postdoctoral Science Foundation(No.2022M722346)+1 种基金the 111 Project(No.B14006)the Yueqi Outstanding Scholar Program of CUMTB(No.2017A03).
文摘Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was conducted.Full-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.
基金Supported by the Laoshan Laboratory(No.LSK 202203003)the National Key R&D Program of China(No.2022YFC3104100)。
文摘The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite data.Mooring observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 mooring.In the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal winter.In addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency currents.The upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 d.Further analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave packets.Moreover,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation period.In addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.
基金the support from the Science and Technology Commission of Shanghai Municipality Municipality(Grant No.21DZ1100500)the Shanghai Municipal Science and Technology Major Project,the Shanghai Frontiers Science Center Program(2021-2025 No.20)+3 种基金the National Key Research and Development Program of China(Grant No.2021YFB2802000)the National Natural Science Foundation of China(Grant No.61975123)the National Natural Science Foundation of China(Grant No.52075504)Fund for Shanxi‘1331Project'Key Subject Construction and Shanxi Doctor Innovation Project(2019).
文摘Nonlinear materials have gained wide interest as saturable absorbers and pulse compression for pulsed laser applications due to their unique optical properties.This work investigates the third-order nonlinear phenomenon of tungsten trioxide(WO_(3))thin films.The giant nonlinear absorption and nonlinear refractive index of WO_(3)thin films were characterized by Z-scan method at 800 nm.We experimentally observed the giant saturable absorption(SA)and nonlinear refractive index of WO_(3)thin films prepared by the seedless layer hydrothermal method,with SA coefficient being as high as-2.59×105cm·GW^(-1).The SA coefficient is at least one order of magnitude larger than those of the conventional semiconductors.The nonlinear refractive index n_(2)of WO_(3)film has been observed for the first time in recent studies and the corresponding coefficient can be up to 1.793 cm^(2)·GW^(-1).The large third-order nonlinear optical(NLO)response enables WO_(3)thin films to be promising candidates for optoelectronic and photonic applications in the near-infrared domain.
基金supported by the National Natural Science Foundation of China(Nos.51827901 and 52121003)the 111 Project(No.B14006)+1 种基金the Yueqi Outstanding Scholar Program of CUMTB(No.2017A03)the Fundamental Research Funds for the Central Universities(No.2022YJSNY13).
文摘Deep in-situ rock mechanics considers the influence of the in-situ environment on mechanical properties,differentiating it from traditional rock mechanics.To investigate the effect of in-situ stress,pore pressure preserved environment on the mechanical difference of sandstone,four tests are numerically modeled by COMSOL:conventional triaxial test,conventional pore pressure test,in-situ stress restoration and reconstruction test,and in-situ pore pressure-preserved test(not yet realized in the laboratory).The in-situ stress restoration parameter is introduced to characterize the recovery effect of in-situ stress on elastic modulus and heterogeneous distribution of sandstone at different depths.A random function and nonuniform pore pressure coefficient are employed to describe the non-uniform distribution of pore pressure in the in-situ environment.Numerical results are compared with existing experimental data to validate the models and calibrate the numerical parameters.By extracting mechanical parameters from numerical cores,the stress-strain curves of the four tests under different depths,in-situ stress and pore pressure are compared.The influence of non-uniform pore pressure coefficient and depth on the peak strength of sandstone is analyzed.The results show a strong linear relationship between the in-situ stress restoration parameter and depth,effectively characterizing the enhanced effect of stress restoration and reconstruction methods on the elastic modulus of conventional cores at different depths.The in-situ pore pressurepreserved test exhibits lower peak stress and peak strain compared to the other three tests,and sandstone subjected to non-uniform pore pressure is more prone to plastic damage and failure.Moreover,the influence of non-uniform pore pressure on peak strength gradually diminished with increasing depth.
基金The work presented in this paper was fully supported by the following projects:National Natural Science Foundation of China(51775196)Guangdong Province Science and Technology Project(2017B090912003)+3 种基金High-level Personnel Special Support Plan of Guangdong Province(2016TQ03X289)The Fundamental Research Funds for the Central Universities(Project No.2018ZD30)Guangdong Province Science and Technology Project(2017B090911014)Guangzhou Science and Technology Project(201704030097)。
文摘In order to meet the clinical requirements of spine surgery,this paper proposed the exploratory research of computer-aided design and selective laser melting(SLM)fabrication of a bionic porous titanium spine implant.The structural design of the spinal implant is based on CT scanning data to ensure correct matching,and the mechanical properties of the implant are verified by simulation analysis and laser selective melting experiment.The surface roughness of the spinal implant manufactured by SLM without post-processing is Ra 15μm,and the implant is precisely jointed with the photosensitive resin model of the upper and lower spine.The surface micro-hardness of the implant is HV 373,tensile strengthσ_(b)=1238.7 MPa,yield strengthσ_(0.2)=1043.9 MPa,the elongation is 6.43%,and the compressive strength of porous structure under 84.60%porosity is 184.09 MPa,which can meet the requirements of the reconstruction of stable spines.Compared with the traditional implant and intervertebral fusion cage,the bionic porous spinal implant has the advantages of accurate fit,porous bionic structure and recovery of patients,and the ion release experiment proved that implants manufactured by SLM are more suitable for clinical application after certain treatments.The elastic modulus of the sample is improved after heat treatment,mainly because the microstructure of the sample changes fromα’phase toα+βdual-phase after heat treatment.In addition,the design of high-quality bionic porous spinal implants still needs to be optimized for the actual needs of doctors.
基金supported by the National Natural Science Foundation of China(91834301 and 21878076)the Science and Technology Commission of Shanghai Municipality(19160712100)。
文摘Conjugated microporous polymer(CMP)is an emerging organic semiconductor withπ-conjugated skeletons,and the bandgap of CMP can be flexibly modulated to harvest visible light.Based on the diversity and adjustability of monomers in CMP,we designed and synthesized donor-accepter(D-A)type BTNCMP through Sonogashira-Hagihara cross-coupling polymerization,further in-situ constructing series of inorganic/organic Z-scheme BW/BTN-n composite in the presence of Bi_(2)WO_(6).After optimization,the tetracycline hydrochloride(C0=10 mg·L^(-1))degradation efficiency reached 84%with BW/BTN-2 as catalyst in 90 min under visible light irradiation,the apparent rate constant k1 is 0.017 min^(-1),which is 1.7 and 5.7 times higher than bare Bi_(2)WO_(6) and BTN-CMP.X-ray photoelectron spectra and UV-Vis diffuse spectra showed that the enhanced photocatalytic activity originated from the tight heterojunction between Bi_(2)WO_(6) and BTN-CMP,which can extend the light absorption range and facilitate the separation and transport of photogenerated charges in the interface of heterojunction.The active species trapping experiments and electron spin resonance technique revealed that h+was the dominant active species during the photodegradation process of tetracycline hydrochloride(TCH).The present study demonstrated the feasibility to construct inorganic/organic composite for the photocatalytic degradation of environmental pollutants.
基金supports of the National Natural Science Foundation of China(21991100)。
文摘As one of the most promising alternative fuels,hydrogen is expected with high hopes.The electrolysis of water is regarded as the cleanest and most efficient method of hydrogen production.Molybdenum disulfide(MoS_(2))is deemed as one of the most promising alternatives HER catalysts owing to its high catalytic activity and low cost.Its continuous production and efficient preparation become the key problems in future industrial production.In this work,we first developed a continuous micro-reaction approach with high heat and mass transfer rates to synthesize few-layer MoS_(2)nanoplates with abundant active sites.The defective MoS_(2)ultrathin nanoplates exhibit excellent HER performance with an overpotential of 260 m V at a current density of 10 m A cm^(-2),small Tafel slope(53.6 m V dec^(-1))and prominent durability,which are comparable to most reported MoS_(2)based catalysts.Considering the existence of continuous devices,it's suitable for the synthesis of MoS_(2)as highperformance electrocatalysts for the industrial water electrolysis.The novel preparation method may open up a new way to synthesize all two-dimension materials toward HER.
基金the National Key Research and Development Program of China(Grant Nos.2017YFA0302904 and 2016YFA0300504)the National Natural Science Founation of China(Grant Nos.U1932215 and 11774419)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33010100)。
文摘The Kitaev spin liquid(KSL) system has attracted tremendous attention in recent years because of its fundamental significance in condensed matter physics and promising applications in fault-tolerant topological quantum computation.Material realization of such a system remains a major challenge in the field due to the unusual configuration of anisotropic spin interactions,though great effort has been made before.Here we reveal that rare-earth chalcohalides REChX(RE=rare earth;Ch=O,S,Se,Te;X=F,Cl,Br,I) can serve as a family of KSL candidates.Most family members have the typical SmSI-type structure with a high symmetry of R3m,and rare-earth magnetic ions form an undistorted honeycomb lattice.The strong spin-orbit coupling of 4f electrons intrinsically offers anisotropic spin interactions as required by the Kitaev model.We have grown the crystals of YbOCl and synthesized the polycrystals of SmSI,ErOF,HoOF and DyOF,and made careful structural characterizations.We carry out magnetic and heat capacity measurements down to 1.8 K and find no obvious magnetic transition in all the samples but DyOF.The van der Waals interlayer coupling highlights the true two-dimensionality of the family which is vital for the exact realization of Abelian/non-Abelian anyons,and the graphene-like feature will be a prominent advantage for developing miniaturized devices.The family is expected to act as an inspiring material platform for the exploration of KSL physics.
基金National Key Research and Development Program of China(2021YFB2800400)National Natural Science Foundation of China(12204021,62105008,62235002,62235003,62322501,8200908114)+3 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Natural Science Foundation of Beijing Municipality(Z210004)Nantong Municipal Science and Technology Bureau(JB2022008,JC22022050)China Postdoctoral Science Foundation(2021T140004)。
文摘Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.
基金financially supported by the National Natural Science Foundation of China (2272142)the Fundamental Research Funds for the Central Universities (20720220031)+1 种基金the 111 Project (B16029)Shenzhen Fundamental Research Programs (JCYJ20190809161013453)。
基金supported by Taishan Scholar Program of Shandong Province,China(ts201712045)Shandong Provincial Key Research and Development Program(SPKR&DP,2019GGX102069)+1 种基金the Natural Science Foundation of Shandong Province of China(ZR2018BB008)the Doctoral Found of Qingdao University of Science and Technology(0100229001,010029081,010029075)。
文摘Amorphous iridium oxides(IrO_(x))are highly active for oxygen evolution reaction(OER)in acid media;however,it is generally unstable compared with commercial IrO_(2).Recently,many non-noble metal-iridium mixed oxides are prepared for catalyzing OER efficiently.Herein,we report a cubic fluorite-type praseodymium iridium oxide with the surface of IrO_(x)(IrO_(x)/Pr_(3)IrO_(7))that shows the improved activity and stability in 0.1 mol L^(-1) HClO_(4) solution,characterized by an overpotential of 305 mV at the benchmark of 10 mA cm^(-2) and a small Tafel slope of 37 mV dec^(-1),indicating a fast reaction kinetics and a competitive activity compared with the benchmark IrO_(2) and most reported electrocatalysts.The initial potential increases by less than 0.07 V after continuous OER testing over 60,000 s.In contrast,IrO_(2) becomes nearly inactive for the OER within 20,000 s.Density functional theory calculations uncover that the optimal energy level path follows lattice oxygen mechanism(LOM).This work enlarges the family of the IrO_(x)-type OER electrocatalyst in acid media.
基金The research of Yanyan Qian is supported by a post-graduate scholarship(Ph.D)of the China Scholarship Council(CSC).
文摘Kuo-Hua Sun(孙国华,1902-1958,courtesy name—Xiao Meng)(Fig.1)was a Chinese psychologist mainly engaged in Physiological Psychology and Child Psychology.Kuo-Hua Sun was born on March 6th,1902,in Weixian,Shandong province.He studied in Tsinghua School from 1914 to 1923.At the same year,Sun attended the education school of Ohio State University,and then received a Bachelor of Psychology(1928)and a Doctor of Philosophy(1929)from Ohio State University.During this period,Sun studied in the Department of Physiology at Chicago University(1925-1926)(Fig.2).
基金the National Key Research and Development Program of China(Grant Nos.2016YFA0401503,2018YFA0305700,2017YFA0302904,2020YFA0711502,and 2016YFA0300500)the National Natural Science Foundation of China(Grant Nos.11575288,11974387,U1932215,U1930401,12004014,22090041,and 11774419)+3 种基金the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant Nos.XDB33000000,XDB25000000,and QYZDBSSW-SLH013)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y202003)the CAS Interdisciplinary Innovation Team(Grant No.JCTD-2019-01)ADXRD measurements were performed at 4W2 High Pressure Station,Beijing Synchrotron Radiation Facility(BSRF),which is supported by the Chinese Academy of Sciences(Grant Nos.KJCX2-SW-N20,and KJCX2-SW-N03)。
文摘The physical properties of most 2D materials are highly dependent on the nature of their interlayer interaction.In-depth studies of the interlayer interaction are beneficial to the understanding of the physical properties of 2D materials and permit the development of related devices.Layered magnetic NiPS_(3)has unique magnetic and electronic properties.The electronic band structure and corresponding magnetic state of NiPS_(3)are expected to be sensitive to the interlayer interaction,which can be tuned by external pressure.Here,we report an insulator-metal transition accompanied by the collapse of magnetic order during the 2D-3D structural crossover induced by hydrostatic pressure.A two-stage phase transition from a monoclinic(C2/m)to a trigonal(P31m)lattice is identified via ab initio simulations and confirmed via high-pressure X-ray diffraction and Raman scattering;this transition corresponds to a layer-by-layer slip mechanism along the a-axis.Temperature-dependent resistance measurements and room temperature infrared spectroscopy under different pressures demonstrate that the insulator-metal transition and the collapse of the magnetic order occur at~20 GPa,which is confirmed by low-temperature Raman scattering measurements and theoretical calculations.These results establish a strong correlation between the structural change,electric transport,and magnetic phase transition and expand our understanding of layered magnetic materials.Moreover,the structural transition caused by the interlayer displacement has significance for designing similar devices at ambient pressure.
基金The project was funded by the National Natural Science Foundation of China(U1708261).
文摘The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.Details of the laboratory construction,virtual autopsy process,case analysis,research and development,establishment of standards,application in teaching,and other aspects of the center are summarized in this paper.In addition,we expound the prospective and practical significance of the virtual anatomy laboratory.Based on computed tomography and magnetic resonance detection methods,the prospective applications of virtual anatomy in forensic identification are explored through the analyses of two real-life cases.Using information from traditional anatomy as the gold standard,this study expanded on and explored the application technology and scenarios of virtual anatomy in imaging,clinical diagnosis,and equipment manufacturing,among other fields.The four cooperating units have their strengths and will yield valuable scientific research results and social benefits.