In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and el...As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.展开更多
Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of a...Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.展开更多
The growing volume of end-of-life lithium-ion batteries(LIBs)represents both an urgent environmental challenge and a critical resource opportunity,especially for cathode materials.Among commercial cathodes,LiFePO4(LFP...The growing volume of end-of-life lithium-ion batteries(LIBs)represents both an urgent environmental challenge and a critical resource opportunity,especially for cathode materials.Among commercial cathodes,LiFePO4(LFP)dominates the market due to its favorable properties;thus,a substantial amount of LFP cathode materials is expected to retire in the near future.The conventional hydrometallurgical method suffers from high costs and serious pollution.Direct regeneration technologies,especially solid-state sintering,provide a more efficient and environmentally benign alternative by repairing cathode structures through high-temperature solid-phase reactions without extra chemical reagents.Traditional solid-state sintering faces challenges in processing spent LFP from diverse sources,struggling to achieve the homogenization of physical–chemical properties and electrochemical performance.To address the limitations above,phase homogenization with a lattice reconstruction strategy has been investigated,which can enable effective lattice reconstruction and microstructural homogenization,demonstrating robust adaptability to spent samples from variable sources.This review systematically summarizes the mechanisms,detailed steps,characterization techniques,and advances in pre-oxidation optimization(including ion-doping and coated carbon layer modification),as well as future research directions for sustainable LFP recycling.Given this,this review is expected to offer theoretical guidance for achieving homogeneous regeneration of LFP cathode.展开更多
The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed...The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed to characterize the track irregularities under different circumstances.The first model is a novel explicit track spectrum function,which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra.On this foundation,the second model,a parameterized track spectrum random model,is proposed to represent the vast measured track irregularities from the probabilistic perspective.Finally,the third model,an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method,is presented to identify the confidential interval of the track spectra when the track irregularity data are limited.Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions.This research can help capture the railway deformation status and optimize track maintenance strategies.展开更多
Among various advanced oxidation processes(AOPs),heterogeneous catalytic ozonation has garnered extensive attention in wastewater treatment owing to its broad pH range applicability and the elimination of the need for...Among various advanced oxidation processes(AOPs),heterogeneous catalytic ozonation has garnered extensive attention in wastewater treatment owing to its broad pH range applicability and the elimination of the need for additional energy input.Enhancing catalyst activity by introducing oxygen vacancies has been used extensively in heterogeneous catalytic ozonation.This paper reviews prevalent methods for the construction and characterization of oxygen vacancies.Based on a thorough examination of existing research,the role of oxygen vacancies is categorized according to their primary mechanisms of action in heterogeneous catalytic ozonation.For example,modulation of the catalyst electronic structure to enhance electron transfer;participation in the reaction as an active site to generate radicals and non-radicals;and exposure of more metal sites to enhance the reaction.Lastly,the paper delineates the limitations and future research directions concerning the role of oxygen vacancies in catalytic ozonation.This review addresses the gap in existing literature concerning the role of oxygen vacancies in catalytic ozone systems,establishes a comprehensive theoretical framework to aid in the design of efficient ozone catalysts,and delves into the functionality of oxygen vacancies in heterogeneous catalytic ozone reactions.展开更多
There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution...There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution process.The sampling strategy of the ultra-sparse angle is an effective method for improving time resolution.Accurate reconstruction under sparse sampling conditions has always been a bottleneck problem.In recent years,convolutional neural networks have shown outstanding advantages in sparse-angle CT reconstruction given the development of deep learning.However,existing ideas did not consider the expression of high-frequency details in neural networks,limiting their application in accurate SR-CT characterization.A novel high-frequency information-constrained deep learning network(HFIC-Net)is proposed in response to this problem.Additional high-frequency information constraints are added to improve the accuracy of the reconstruction results.Further,a series of numerical reconstruction experiments are conducted to verify this new method,and the results indicate that the reconstruction results of HFIC-Net method effectively improve reconstruction quality.This new method uses only eight-angle projections to achieve the reconstruction effect of the filtered backprojection method(FBP)method in 360 projections.The results of the HFIC-Net method demonstrate clear boundaries and accurate detailed structures,correcting the misinformation caused by using other methods.For quantitative evaluation,the SSIM used to evaluate image structure similarity is increased from 0.1951,0.9212,and 0.9308 for FBP,FBP-Conv,and DDC-Net,respectively,to 0.9620 for HFIC-Net.Finally,the results of actual SR-CT experimental data indicate that the new method can suppress artifacts and achieve accurate reconstruction,and it is suitable for the in situ SR-CT accurate characterization of ultxafast evolution process.展开更多
The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment....The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.In this study,terrestrial laser scanning(TLS)and unmanned aerial vehicle(UAV)technologies were integrated to enhance the evaluation methodology for rock mass hazard sources,focusing on the Sichuan Yanjiang Expressway project in China.The findings demonstrate that TLS-UAV technology enhanced both spatial coverage and data density in slope modeling.Through integrated algorithmic analysis,rock discontinuities within heterogeneous datasets were systematically identified,enabling quantitative extraction and statistical analysis of key geometric parameters,including orientation,trace length,spacing,and roughness.Furthermore,quantitative models were developed for cohesion,friction angle and the morphology parameter M of in situ discontinuities,respectively,facilitating efficient mechanical parameter acquisition.A novel rock mass hazard index(RHI)was developed incorporating discontinuity geometric rating(DGR),discontinuity mechanical rating(DMR),and slope mass rating(SMR).Field validation confirmed the methodology's effectiveness in evaluating risk levels and spatial heterogeneity of rock mass hazard sources,revealing the contribution of different discontinuity sets to the rock mass hazard and identifying the primary discontinuity sets controlling instability mechanisms.This study is of great significance for evaluating discontinuity-controlled rock mass hazard sources and preventing rockfall disasters.展开更多
Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensi...Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(2 D-LC/IM-QTOF-MS)enabling four-dimensional separations(2 D-LC,IM,and MS),is proposed.In combination with in-house database-driven automated peak annotation,this strategy was utilized to characterize ginsenosides simultaneously from white ginseng(WG)and red ginseng(RG).An offline 2 DLC system configuring an Xbridge Amide column and an HSS T3 column showed orthogonality 0.76 in the resolution of ginsenosides.Ginsenoside analysis was performed by data-independent high-definition MSE(HDMSE)in the negative ESI mode on a Vion?IMS-QTOF hybrid high-resolution mass spectrometer,which could better resolve ginsenosides than MSEand directly give the CCS information.An in-house ginsenoside database recording 504 known ginsenosides and 58 reference compounds,was established to assist the identification of ginsenosides.Streamlined workflows,by applying UNIFI?to automatedly annotate the HDMSEdata,were proposed.We could separate and characterize 323 ginsenosides(including 286 from WG and 306 from RG),and 125 thereof may have not been isolated from the Panax genus.The established 2 D-LC/IM-QTOF-HDMSEapproach could also act as a magnifier to probe differentiated components between WG and RG.Compared with conventional approaches,this dimensionenhanced strategy could better resolve coeluting herbal components and more efficiently,more reliably identify the multicomponents,which,we believe,offers more possibilities for the systematic exposure and confirmative identification of plant metabolites.展开更多
Owing to their rolling friction,two-dimensional piston pumps are highly suitable as power components for electro-hydrostatic actuators(EHAs).These pumps are particularly advantageous for applications requiring high ef...Owing to their rolling friction,two-dimensional piston pumps are highly suitable as power components for electro-hydrostatic actuators(EHAs).These pumps are particularly advantageous for applications requiring high efficiency and reliability.However,the ambiguity surrounding the output flow characteristics of individual two-dimensional pumps poses a significant challenge in achieving precise closed-loop control of the EHA positions.To address this issue,this study established a comprehensive numerical model that included gap leakage to analyze the impact of leakage on the output flow characteristics of a two-dimensional piston pump.The validity of the numerical analysis was indirectly confirmed through meticulous measurements of the leakage and volumetric efficiency,ensuring robust results.The research findings indicated that,at lower pump speeds,leakage significantly affected the output flow rate,leading to potential inefficiencies in the system.Conversely,at higher rotational speeds,the impact of leakage was less pronounced,implying that the influence of leakage on the pump outlet flow must be carefully considered and managed for EHAs to perform position servo control.Additionally,the research demonstrates that two-dimensional motion does not have a unique or additional effect on pump leakage,thus simplifying the design considerations.Finally,the study concluded that maintaining an oil-filled leakage environment is beneficial because it helps reduce the impact of leakage and enhances the overall volumetric efficiency of the pump system.展开更多
Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and wea...Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and weak out-of-plane van der Waals （vdW） interactions make 2D materials promising for nanodevices and various other applications. Raman spectroscopy is a powerful and non-destructive characterization tool to study the properties of 2D materials. In this work, we review the research on the characterization of 2D materials with Raman spectroscopy. In addition, we discuss the application of the Raman spectroscopy technique to semiconductors, superconductivity, photoelectricity, and thermoelectricity.展开更多
The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with ...The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with a sulfur chemiluminescence detector to harvest a satisfactory result. The identification of the structure of sulfur compounds by comprehensive two-dimensional gas chromatography coupled with the time-of-flight mass spectrometry indicated that cyclo-sulfides, benzothiophenes, dibenzothiophenes, dihydro-benzothiophenes and tetrahydro-dibenzothiophenes were included in straightrun diesel obtained from the Arab medium crude(AM). A total of 259 individual compounds were detected and their molecular structures were identified. The analytical method was approved as an effective way to characterize the composition of sulfur compounds, which reduced the interference of other compounds, facilitated the data presentation and provided more detailed information about molecular composition of sulfur compounds.展开更多
Two-dimensional polymers(2DPs)are emerging crystalline 2D organic material comprising free-standing,single-atom/monomer-thick,planar,and covalent networks with long-ranging structural order.Benefiting from their intri...Two-dimensional polymers(2DPs)are emerging crystalline 2D organic material comprising free-standing,single-atom/monomer-thick,planar,and covalent networks with long-ranging structural order.Benefiting from their intrinsic porosity,crystallinity,and electrical properties,2DPs have displayed great potential for separation,energy conversion and electronic fields.In this mini review,we aim to provide the recent progress in crystalline 2DPs films form synthesis strategies to characterization methods,as well as the future trends.We first present the synthesis strategy of single-crystalline 2DPs films including crystal engineering approaches and surface science.Also,we summarize the characterization methods of 2DPs films and highlight the advantages and limitations of different methods focusing on chemical bonding,morphology,and crystal structure.Finally,we will present the current challenges and trends regarding the future developments of crystallinity,monomer design,synthesis strategy and characterization.展开更多
A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4,4'-alkylenedioxy...A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4,4'-alkylenedioxydibenzoic acid. The polymers were characterized by using polarized microscopy, DSC and X-ray diffraction. It was realized that all the polymers have nematic thermotropic liquid crystallinecharacteristics. The melting temperature (T_m) and isotropization temperature (T_i) of the polymers changeregularly with varying lengths of the alkoxy side group and the length of the alkylene group in the main chainin company with an even-odd effect. The mesophase temperature range also varies regularly with the polymerstructure. It is shown that the mesophase range has been widened.展开更多
A series of liquid crystalline polymers with T-shaped two-dimensional mesogenic unitswere synthesized via low temperature solution polycondensation of 2-(4'-alkoxy-phenyl)hydroquinone with various diacyl dichlorid...A series of liquid crystalline polymers with T-shaped two-dimensional mesogenic unitswere synthesized via low temperature solution polycondensation of 2-(4'-alkoxy-phenyl)hydroquinone with various diacyl dichlorides. The polymers were found to be nematic andshown thermotropic liquid crystalline behaviors through observations using DSC, polarizedmicroscopy and X-ray diffraction. The melting temperature T_m and the isotropizationtemperature T_i of the polymers change regularly with varying of the monomer structures.展开更多
A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characteri...A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characterized by means of single-crystal X-ray diffraction, elemental analyses, IR, EPR spectra and thermal analyses. C_ 16H_ 80Cu_4Mo_ 5.5N_ 16O_ 51PV_ 10.5 crystallized in a triclinic system, the space group is P1 with M=2660.63, a= 1.283590(10) nm, b=1.289910(10) nm, c=1.387870(10) nm, V=1.80942(2) nm 3, Z=2, D_x=4.883 g/cm 3, F(000)=2599, μ=6.956 mm -1, (Δ/σ)=0.000, S=1.089. The crystal structure was solved by the direct methods with the final R=0.0752 and wR=0.1988 for 6311 observed reflections with I≥2σ(I). The X-ray crystallography reveals that compound 1 is a novel two-dimensional framework material constructed from the mixed Mo/V polyoxometalate and coordination groups.展开更多
Two series of new liquid crystalline polymers with T-shaped two-dimensional mesogenic units were synthesized by low temperature solution polycondensations of 4-substituted N-2, 5-dihydroxybenzylidene aniline monomers ...Two series of new liquid crystalline polymers with T-shaped two-dimensional mesogenic units were synthesized by low temperature solution polycondensations of 4-substituted N-2, 5-dihydroxybenzylidene aniline monomers with different diacyl dichlorides. The polymers were found to be nematic and shown liquid crystalline behavior. The melting temperature T-m and the clearing temperature T-i of the polymers change regularly with varying of the monomer structures.展开更多
To study the energy storage and dissipation characteristics of deep rock under two-dimensional compression with constant confining pressure,the single cyclic loading-unloading two-dimensional compression tests were pe...To study the energy storage and dissipation characteristics of deep rock under two-dimensional compression with constant confining pressure,the single cyclic loading-unloading two-dimensional compression tests were performed on granite specimens with two height-to-width(H/W)ratios under five confining pressures.Three energy density parameters(input energy density,elastic energy density and dissipated energy density)in the axial and lateral directions of granite specimens under different confining pressures were calculated using the area integral method.The experimental results show that,for the specimens with a specific H/W ratio,these three energy density parameters in the axial and lateral directions increase nonlinearly with the confining pressure as quadratic polynomial functions.Under constant confining pressure compression,the linear energy storage law of granite specimens in the axial and lateral directions was founded.Using the linear energy storage law in different directions,the elastic energy density in various directions(axial elastic energy density,lateral elastic energy density and total elastic energy density)of granite under any specific confining pressures can be calculated.When the H/W ratio varies from 1:1 to 2:1,the lateral compression energy storage coefficient increases and the corresponding axial compression energy storage coefficient decreases,while the total compression energy storage coefficient is almost independent of the H/W ratio.展开更多
Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the preven...Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the prevention and control of LF.Methods Samples of cerebrospinal fluid(CSF),blood,urine,saliva,and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection.Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus.Results LASV was detected in the patient’s CSF,blood,and urine,while all samples from close contacts and the environment tested negative.The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone.The variability in the glycoprotein complex(GPC)among different strains ranged from 3.9%to 15.1%,higher than previously reported for the seven known lineages.Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes,increasing strain diversity and potentially impacting immune response.Conclusion The case was confirmed through nucleotide detection,with no evidence of secondary transmission or viral spread.The LASV strain identified belongs to lineage IV,with broader GPC variability than previously reported.Mutations in the immune-related sites of GPC may affect immune responses,necessitating heightened vigilance regarding the virus.展开更多
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
基金supported by the NSFC(12474071)Natural Science Foundation of Shandong Province(ZR2024YQ051,ZR2025QB50)+6 种基金Guangdong Basic and Applied Basic Research Foundation(2025A1515011191)the Shanghai Sailing Program(23YF1402200,23YF1402400)funded by Basic Research Program of Jiangsu(BK20240424)Open Research Fund of State Key Laboratory of Crystal Materials(KF2406)Taishan Scholar Foundation of Shandong Province(tsqn202408006,tsqn202507058)Young Talent of Lifting engineering for Science and Technology in Shandong,China(SDAST2024QTB002)the Qilu Young Scholar Program of Shandong University。
文摘As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.
基金supported by the Fundamental Research Funds for the Central Universities(WUT:2024IVA052 and Grant No.104972025KFYjc0089)。
文摘Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.
基金financially supported by National Natural Science Key Foundation of China(52534010)National Natural Science Foundation of China(52374288,52204298)+2 种基金Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001)National Key Research and Development Program of China(2022YFC3900805-4/7)Collaborative Innovation Centre for Clean and Efficient Utilization of Strategic Metal Mineral Resources,Found of State Key Laboratory of Mineral Processing(BGRIMM-KJSKL-2017-13).
文摘The growing volume of end-of-life lithium-ion batteries(LIBs)represents both an urgent environmental challenge and a critical resource opportunity,especially for cathode materials.Among commercial cathodes,LiFePO4(LFP)dominates the market due to its favorable properties;thus,a substantial amount of LFP cathode materials is expected to retire in the near future.The conventional hydrometallurgical method suffers from high costs and serious pollution.Direct regeneration technologies,especially solid-state sintering,provide a more efficient and environmentally benign alternative by repairing cathode structures through high-temperature solid-phase reactions without extra chemical reagents.Traditional solid-state sintering faces challenges in processing spent LFP from diverse sources,struggling to achieve the homogenization of physical–chemical properties and electrochemical performance.To address the limitations above,phase homogenization with a lattice reconstruction strategy has been investigated,which can enable effective lattice reconstruction and microstructural homogenization,demonstrating robust adaptability to spent samples from variable sources.This review systematically summarizes the mechanisms,detailed steps,characterization techniques,and advances in pre-oxidation optimization(including ion-doping and coated carbon layer modification),as well as future research directions for sustainable LFP recycling.Given this,this review is expected to offer theoretical guidance for achieving homogeneous regeneration of LFP cathode.
基金supported by the National Natural Science Foundation of China(Grant No.52208445,52478321,52378468)the Fundamental Research Funds for the Central Universities(Grant No.G2021KY05105)+7 种基金the Basic Research Program of Natural Science in Shaanxi Province(Grant No.2022JQ-369)the Open Foundation of National Engineering Laboratory for High Speed Railway Construction(No.HSR202001)the Youth Talent Support Program Project of Xi’an Association for Science and Technology(Grant No.959202413090)Science and Technology Research and Development Program Project of China railway group limited(Major Special Project,No.:2020-Special-022021-Special-082023-Special-07)Innovation-driven project of Central South University(2023CXQD072)the National Natural Science Foundation of Hunan Province(Grant No.:2022-JJ-20071).
文摘The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed to characterize the track irregularities under different circumstances.The first model is a novel explicit track spectrum function,which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra.On this foundation,the second model,a parameterized track spectrum random model,is proposed to represent the vast measured track irregularities from the probabilistic perspective.Finally,the third model,an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method,is presented to identify the confidential interval of the track spectra when the track irregularity data are limited.Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions.This research can help capture the railway deformation status and optimize track maintenance strategies.
基金support from the Key R&D Program of Zhejiang province(No.2024C03136).
文摘Among various advanced oxidation processes(AOPs),heterogeneous catalytic ozonation has garnered extensive attention in wastewater treatment owing to its broad pH range applicability and the elimination of the need for additional energy input.Enhancing catalyst activity by introducing oxygen vacancies has been used extensively in heterogeneous catalytic ozonation.This paper reviews prevalent methods for the construction and characterization of oxygen vacancies.Based on a thorough examination of existing research,the role of oxygen vacancies is categorized according to their primary mechanisms of action in heterogeneous catalytic ozonation.For example,modulation of the catalyst electronic structure to enhance electron transfer;participation in the reaction as an active site to generate radicals and non-radicals;and exposure of more metal sites to enhance the reaction.Lastly,the paper delineates the limitations and future research directions concerning the role of oxygen vacancies in catalytic ozonation.This review addresses the gap in existing literature concerning the role of oxygen vacancies in catalytic ozone systems,establishes a comprehensive theoretical framework to aid in the design of efficient ozone catalysts,and delves into the functionality of oxygen vacancies in heterogeneous catalytic ozone reactions.
基金supported by the National Nature Science Foundation of China(Nos.12027901 and 12041202)Synchrotron Radiation Joint Fund of University of Science and Technology of China(Nos.KY2090000059 and KY2090000054)。
文摘There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution process.The sampling strategy of the ultra-sparse angle is an effective method for improving time resolution.Accurate reconstruction under sparse sampling conditions has always been a bottleneck problem.In recent years,convolutional neural networks have shown outstanding advantages in sparse-angle CT reconstruction given the development of deep learning.However,existing ideas did not consider the expression of high-frequency details in neural networks,limiting their application in accurate SR-CT characterization.A novel high-frequency information-constrained deep learning network(HFIC-Net)is proposed in response to this problem.Additional high-frequency information constraints are added to improve the accuracy of the reconstruction results.Further,a series of numerical reconstruction experiments are conducted to verify this new method,and the results indicate that the reconstruction results of HFIC-Net method effectively improve reconstruction quality.This new method uses only eight-angle projections to achieve the reconstruction effect of the filtered backprojection method(FBP)method in 360 projections.The results of the HFIC-Net method demonstrate clear boundaries and accurate detailed structures,correcting the misinformation caused by using other methods.For quantitative evaluation,the SSIM used to evaluate image structure similarity is increased from 0.1951,0.9212,and 0.9308 for FBP,FBP-Conv,and DDC-Net,respectively,to 0.9620 for HFIC-Net.Finally,the results of actual SR-CT experimental data indicate that the new method can suppress artifacts and achieve accurate reconstruction,and it is suitable for the in situ SR-CT accurate characterization of ultxafast evolution process.
基金support from the National Natural Science Foundation of China(Grant Nos.42177142 and 52378477)the Key Research and Development Program of Shaanxi(Grant No.2023-YBSF-486).
文摘The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.In this study,terrestrial laser scanning(TLS)and unmanned aerial vehicle(UAV)technologies were integrated to enhance the evaluation methodology for rock mass hazard sources,focusing on the Sichuan Yanjiang Expressway project in China.The findings demonstrate that TLS-UAV technology enhanced both spatial coverage and data density in slope modeling.Through integrated algorithmic analysis,rock discontinuities within heterogeneous datasets were systematically identified,enabling quantitative extraction and statistical analysis of key geometric parameters,including orientation,trace length,spacing,and roughness.Furthermore,quantitative models were developed for cohesion,friction angle and the morphology parameter M of in situ discontinuities,respectively,facilitating efficient mechanical parameter acquisition.A novel rock mass hazard index(RHI)was developed incorporating discontinuity geometric rating(DGR),discontinuity mechanical rating(DMR),and slope mass rating(SMR).Field validation confirmed the methodology's effectiveness in evaluating risk levels and spatial heterogeneity of rock mass hazard sources,revealing the contribution of different discontinuity sets to the rock mass hazard and identifying the primary discontinuity sets controlling instability mechanisms.This study is of great significance for evaluating discontinuity-controlled rock mass hazard sources and preventing rockfall disasters.
基金the National Natural Science Foundation of China(Grant No.81872996)the State Key Research and Development Project(Grant No.2017YFC1702104)+1 种基金the State Key Project for the Creation of Major New Drugs(2018ZX09711001-009-010)the Tianjin Municipal Education Commission Research Project(Grant No.2017ZD07)。
文摘Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(2 D-LC/IM-QTOF-MS)enabling four-dimensional separations(2 D-LC,IM,and MS),is proposed.In combination with in-house database-driven automated peak annotation,this strategy was utilized to characterize ginsenosides simultaneously from white ginseng(WG)and red ginseng(RG).An offline 2 DLC system configuring an Xbridge Amide column and an HSS T3 column showed orthogonality 0.76 in the resolution of ginsenosides.Ginsenoside analysis was performed by data-independent high-definition MSE(HDMSE)in the negative ESI mode on a Vion?IMS-QTOF hybrid high-resolution mass spectrometer,which could better resolve ginsenosides than MSEand directly give the CCS information.An in-house ginsenoside database recording 504 known ginsenosides and 58 reference compounds,was established to assist the identification of ginsenosides.Streamlined workflows,by applying UNIFI?to automatedly annotate the HDMSEdata,were proposed.We could separate and characterize 323 ginsenosides(including 286 from WG and 306 from RG),and 125 thereof may have not been isolated from the Panax genus.The established 2 D-LC/IM-QTOF-HDMSEapproach could also act as a magnifier to probe differentiated components between WG and RG.Compared with conventional approaches,this dimensionenhanced strategy could better resolve coeluting herbal components and more efficiently,more reliably identify the multicomponents,which,we believe,offers more possibilities for the systematic exposure and confirmative identification of plant metabolites.
基金Supported by National Natural Science Foundation of China(Grant No.52205072).
文摘Owing to their rolling friction,two-dimensional piston pumps are highly suitable as power components for electro-hydrostatic actuators(EHAs).These pumps are particularly advantageous for applications requiring high efficiency and reliability.However,the ambiguity surrounding the output flow characteristics of individual two-dimensional pumps poses a significant challenge in achieving precise closed-loop control of the EHA positions.To address this issue,this study established a comprehensive numerical model that included gap leakage to analyze the impact of leakage on the output flow characteristics of a two-dimensional piston pump.The validity of the numerical analysis was indirectly confirmed through meticulous measurements of the leakage and volumetric efficiency,ensuring robust results.The research findings indicated that,at lower pump speeds,leakage significantly affected the output flow rate,leading to potential inefficiencies in the system.Conversely,at higher rotational speeds,the impact of leakage was less pronounced,implying that the influence of leakage on the pump outlet flow must be carefully considered and managed for EHAs to perform position servo control.Additionally,the research demonstrates that two-dimensional motion does not have a unique or additional effect on pump leakage,thus simplifying the design considerations.Finally,the study concluded that maintaining an oil-filled leakage environment is beneficial because it helps reduce the impact of leakage and enhances the overall volumetric efficiency of the pump system.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504111,61574060,and 61574056)the Projects of Science and Technology Commission of Shanghai Municipality of China(Grant Nos.15JC1401800 and 14DZ2260800)+2 种基金the Program for Professor of Special Appointment(Eastern Scholar)Shanghai Rising-Star Program,China(Grant No.17QA1401400)the Fundamental Research Funds for the Central Universities of China
文摘Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and weak out-of-plane van der Waals （vdW） interactions make 2D materials promising for nanodevices and various other applications. Raman spectroscopy is a powerful and non-destructive characterization tool to study the properties of 2D materials. In this work, we review the research on the characterization of 2D materials with Raman spectroscopy. In addition, we discuss the application of the Raman spectroscopy technique to semiconductors, superconductivity, photoelectricity, and thermoelectricity.
基金financially supported by the National Basic Research Program of China (973 Program) (2012CB224800)
文摘The solid-phase extraction using Pd-Al2O3 as the stationary phase was employed to pre-separate the sulfur compounds in straight-run diesel. The isolating effect was evaluated quantitatively by gas chromatography with a sulfur chemiluminescence detector to harvest a satisfactory result. The identification of the structure of sulfur compounds by comprehensive two-dimensional gas chromatography coupled with the time-of-flight mass spectrometry indicated that cyclo-sulfides, benzothiophenes, dibenzothiophenes, dihydro-benzothiophenes and tetrahydro-dibenzothiophenes were included in straightrun diesel obtained from the Arab medium crude(AM). A total of 259 individual compounds were detected and their molecular structures were identified. The analytical method was approved as an effective way to characterize the composition of sulfur compounds, which reduced the interference of other compounds, facilitated the data presentation and provided more detailed information about molecular composition of sulfur compounds.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LR21E030001).
文摘Two-dimensional polymers(2DPs)are emerging crystalline 2D organic material comprising free-standing,single-atom/monomer-thick,planar,and covalent networks with long-ranging structural order.Benefiting from their intrinsic porosity,crystallinity,and electrical properties,2DPs have displayed great potential for separation,energy conversion and electronic fields.In this mini review,we aim to provide the recent progress in crystalline 2DPs films form synthesis strategies to characterization methods,as well as the future trends.We first present the synthesis strategy of single-crystalline 2DPs films including crystal engineering approaches and surface science.Also,we summarize the characterization methods of 2DPs films and highlight the advantages and limitations of different methods focusing on chemical bonding,morphology,and crystal structure.Finally,we will present the current challenges and trends regarding the future developments of crystallinity,monomer design,synthesis strategy and characterization.
基金This work was supported by the National Natural Science Foundation of China.
文摘A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4,4'-alkylenedioxydibenzoic acid. The polymers were characterized by using polarized microscopy, DSC and X-ray diffraction. It was realized that all the polymers have nematic thermotropic liquid crystallinecharacteristics. The melting temperature (T_m) and isotropization temperature (T_i) of the polymers changeregularly with varying lengths of the alkoxy side group and the length of the alkylene group in the main chainin company with an even-odd effect. The mesophase temperature range also varies regularly with the polymerstructure. It is shown that the mesophase range has been widened.
基金This work was supported by the National Natural Science Foundation of China.
文摘A series of liquid crystalline polymers with T-shaped two-dimensional mesogenic unitswere synthesized via low temperature solution polycondensation of 2-(4'-alkoxy-phenyl)hydroquinone with various diacyl dichlorides. The polymers were found to be nematic andshown thermotropic liquid crystalline behaviors through observations using DSC, polarizedmicroscopy and X-ray diffraction. The melting temperature T_m and the isotropizationtemperature T_i of the polymers change regularly with varying of the monomer structures.
文摘A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characterized by means of single-crystal X-ray diffraction, elemental analyses, IR, EPR spectra and thermal analyses. C_ 16H_ 80Cu_4Mo_ 5.5N_ 16O_ 51PV_ 10.5 crystallized in a triclinic system, the space group is P1 with M=2660.63, a= 1.283590(10) nm, b=1.289910(10) nm, c=1.387870(10) nm, V=1.80942(2) nm 3, Z=2, D_x=4.883 g/cm 3, F(000)=2599, μ=6.956 mm -1, (Δ/σ)=0.000, S=1.089. The crystal structure was solved by the direct methods with the final R=0.0752 and wR=0.1988 for 6311 observed reflections with I≥2σ(I). The X-ray crystallography reveals that compound 1 is a novel two-dimensional framework material constructed from the mixed Mo/V polyoxometalate and coordination groups.
基金Tins work was supported by the National Natural Science Foundation of China.
文摘Two series of new liquid crystalline polymers with T-shaped two-dimensional mesogenic units were synthesized by low temperature solution polycondensations of 4-substituted N-2, 5-dihydroxybenzylidene aniline monomers with different diacyl dichlorides. The polymers were found to be nematic and shown liquid crystalline behavior. The melting temperature T-m and the clearing temperature T-i of the polymers change regularly with varying of the monomer structures.
基金Projects(41877272,51974359)supported by the National Natural Science Foundation of China。
文摘To study the energy storage and dissipation characteristics of deep rock under two-dimensional compression with constant confining pressure,the single cyclic loading-unloading two-dimensional compression tests were performed on granite specimens with two height-to-width(H/W)ratios under five confining pressures.Three energy density parameters(input energy density,elastic energy density and dissipated energy density)in the axial and lateral directions of granite specimens under different confining pressures were calculated using the area integral method.The experimental results show that,for the specimens with a specific H/W ratio,these three energy density parameters in the axial and lateral directions increase nonlinearly with the confining pressure as quadratic polynomial functions.Under constant confining pressure compression,the linear energy storage law of granite specimens in the axial and lateral directions was founded.Using the linear energy storage law in different directions,the elastic energy density in various directions(axial elastic energy density,lateral elastic energy density and total elastic energy density)of granite under any specific confining pressures can be calculated.When the H/W ratio varies from 1:1 to 2:1,the lateral compression energy storage coefficient increases and the corresponding axial compression energy storage coefficient decreases,while the total compression energy storage coefficient is almost independent of the H/W ratio.
基金supported by Public Health Talent Training and Surport Plan(National Administration of Disease Prevention and Control)Research and application of new technology for rapid monitoring and tracing of emergent infectious diseases among entry-exit population(2024YFFK0056)Monitoring,Early warning and Response of Major Infectious Diseases(2022ZDZX0017).
文摘Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the prevention and control of LF.Methods Samples of cerebrospinal fluid(CSF),blood,urine,saliva,and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection.Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus.Results LASV was detected in the patient’s CSF,blood,and urine,while all samples from close contacts and the environment tested negative.The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone.The variability in the glycoprotein complex(GPC)among different strains ranged from 3.9%to 15.1%,higher than previously reported for the seven known lineages.Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes,increasing strain diversity and potentially impacting immune response.Conclusion The case was confirmed through nucleotide detection,with no evidence of secondary transmission or viral spread.The LASV strain identified belongs to lineage IV,with broader GPC variability than previously reported.Mutations in the immune-related sites of GPC may affect immune responses,necessitating heightened vigilance regarding the virus.
