In high-speed railway(HSR)wireless communication,the rapid channel changes and limited high-capacity access cause significant impact on the link performance.Meanwhile,the Doppler shift caused by high mobility leads to...In high-speed railway(HSR)wireless communication,the rapid channel changes and limited high-capacity access cause significant impact on the link performance.Meanwhile,the Doppler shift caused by high mobility leads to the inter-carrier interference.In this paper,we propose a reconfigurable intelligent surface(RIS)-assisted receive spatial modulation(SM)scheme based on the spatial-temporal correlated HSR Rician channel.The characteristics of SM and the phase shift adjustment of RIS are used to mitigate the performance degradation in high mobility scenarios.Considering the influence of channel spatial-temporal correlation and Doppler shift,the effects of different parameters on average bit error rate(BER)performance and upper bound of ergodic capacity are analyzed.Therefore,a joint antenna and RIS-unit selection algorithm based on the antenna removal method is proposed to increase the capacity performance of communication links.Numerical results show that the proposed RIS-assisted receive SM scheme can maintain high transmission capacity compared to the conventional HSR-SM scheme,whereas the degradation of BER performance can be compensated by arranging a large number of RIS-units.In addition,selecting more RIS-units has better capacity performance than activating more antennas in the low signal-to-noise ratio regions.展开更多
[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau...[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.展开更多
As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure...As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure the performance protection requirements.In order to clarify the rain erosion damage mechanism of radome coating and explore the influencing factors and mechanisms of coating material damage under different jet impact conditions,impact tests were conducted on three types of skin coating samples,and the damage mode was observed through electron microscopy characterization.The experimental results show that the typical morphology of rain erosion damage is annular surface peeling damage.The damage area and volume of the three coating samples increase with the continuous increase of raindrop impact velocity.The threshold velocity for initial damage to the coating is about 360 m/s;under the influence of the velocity component,the reduction in impact angle leads to a gradual reduction in the degree of damage to the sample.ABAQUS finite element simulation software was used to establish a constitutive model for coating rain erosion simulation and obtain the propagation law of stress waves during the impact process.The simulation results show that at the 75°impact angle,the jet impacts the surface of the specimen at different velocities,and as the impact velocity increases,the Mises equivalent stress on the surface shows an increasing trend,which is one of the main factors causing damage with increasing velocity.The effectiveness,rain erosion damage mode,and influencing mechanism of the model were verified based on the test results;the dynamic failure mechanism of the sample was further studied,and the stress propagation process at different impact angles was compared,revealing the influence mechanism and damage law of the impact angle on the high-speed raindrop impact of the material.展开更多
This paper studies the structural response of high-speed train wipers under the combined action of complex flow fields and scraping actions.The stress concentration areas are determined through simulation analysis,and...This paper studies the structural response of high-speed train wipers under the combined action of complex flow fields and scraping actions.The stress concentration areas are determined through simulation analysis,and the stress and aerodynamic load measurement points are reasonably arranged accordingly.The actual measurement is carried out in combination with the operating conditions of the existing lines.The stress variations and spectral characteristics of the train under different speed levels(80,160,180,200 km/h),tunnel entry and exit,and scraper action conditions were compared and analyzed.The stress amplification factors under tunnel intersection and scraper action were obtained,providing boundary conditions for the design of wipers for highspeed s.The research results show that the maximum stress of the wiper structure obtained through simulation calculation is concentrated at the connection of the wiper arm.Structural stress increases with the rise of speed grade.The stress increases by 1.11 times when the tunnel meets.When the scraper operates,the stress on the scraper arm increases by 4.1–7.6 times.Due to the broadband excitation effect of the aerodynamic load,the spectral energy of the structure is relatively high at the natural frequency,which excites the natural mode of the wiper.展开更多
While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance re...While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.展开更多
Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,...Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,including infrastructure,traction power supply,operational planning,and overall railway safety.This article focuses on evaluating the capacity of the line based on the types of signals suitable for high-speed railways that have been effectively implemented in several European countries and successfully adapted in China.The research and simulation are conducted using MATLAB software,a reliable and widely adopted tool in the scientific community.The findings demonstrate that under normal conditions,the European Railway Traffic Management System/European Train Control System(ERTMS/ETCS)Level 2 signaling can support up to 23.7485 trains/hour/direction.Meanwhile,ERTMS/ETCS Level 3 with full moving block can accommodate up to 30.8735 trains/hour/direction,and ERTMS/ETCS Level 3 with fixed virtual blocks up to 29.4694 trains/hour/direction.In emergency scenarios,ERTMS/ETCS Level 3 with full moving block reduces headway by 33.27%compared to CTCS Level 3,while ERTMS/ETCS Level 3 with fixed virtual blocks achieves a 28.78%reduction.Overall,the ERTMS/ETCS Level 3 emerges as a state-of-the-art signaling technology offering high capacity and operational efficiency,and is recommended as a forward-looking solution for future implementation in Vietnam.展开更多
The spatial offset of bridge has a significant impact on the safety,comfort,and durability of high-speed railway(HSR)operations,so it is crucial to rapidly and effectively detect the spatial offset of operational HSR ...The spatial offset of bridge has a significant impact on the safety,comfort,and durability of high-speed railway(HSR)operations,so it is crucial to rapidly and effectively detect the spatial offset of operational HSR bridges.Drive-by monitoring of bridge uneven settlement demonstrates significant potential due to its practicality,cost-effectiveness,and efficiency.However,existing drive-by methods for detecting bridge offset have limitations such as reliance on a single data source,low detection accuracy,and the inability to identify lateral deformations of bridges.This paper proposes a novel drive-by inspection method for spatial offset of HSR bridge based on multi-source data fusion of comprehensive inspection train.Firstly,dung beetle optimizer-variational mode decomposition was employed to achieve adaptive decomposition of non-stationary dynamic signals,and explore the hidden temporal relationships in the data.Subsequently,a long short-term memory neural network was developed to achieve feature fusion of multi-source signal and accurate prediction of spatial settlement of HSR bridge.A dataset of track irregularities and CRH380A high-speed train responses was generated using a 3D train-track-bridge interaction model,and the accuracy and effectiveness of the proposed hybrid deep learning model were numerically validated.Finally,the reliability of the proposed drive-by inspection method was further validated by analyzing the actual measurement data obtained from comprehensive inspection train.The research findings indicate that the proposed approach enables rapid and accurate detection of spatial offset in HSR bridge,ensuring the long-term operational safety of HSR bridges.展开更多
Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may com...Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may compromise their fatigue capacity.The most common structural design for railway noise barriers consists of vertical configurations of posts and panels.However,there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads.This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers.Analysis of a 40-m-long noise barrier model and a triangular simplified load model,the latter of which effectively represented the detailed aerodynamic load,were first used to establish the model and input of the moving load during dynamic simulation.Then,the effects of different parameters on the dynamic response of the noise barrier were evaluated,including the damping ratio,the profile of the steel post,the span length of the panel,the barrier height,and the train speed.Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses,followed by train speed,post profile,span length,and damping ratio.A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves.The dynamic amplification factor(DAF)was found to be related to both the natural frequency and train speed.A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.展开更多
The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet...The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet the mechanisms underlying these antithetical behaviors are still under investigation.In this study,we explore the modulation of the open-circuit voltage(Voc)in triple-cation mixed-halide perovskite solar cells by systematically controlling storage environments.While light intensity exhibits minimal impact during storage,the spectral composition of illumination selectively enhances Voc comprising reversible and irreversible contributions.Structural characterization reveals that prolonged storage degrades the quality of perovskite crystals in the upper region of the perovskite layer,whereas light storage promotes the relaxation of microstrain at the buried interface with a p-type organic layer.This structural reorganization at the interface,accompanied by lattice expansion,accounts for suppressed nonradiative recombination and a corresponding increase in quasi-Fermi level splitting.Consequently,devices fabricated without chemical defect passivation achieve a power conversion efficiency of higher than 40%under indoor lighting conditions after preconditioned by continuous exposure to ambient light during storage.These findings highlight the critical role of controlled light exposure during storage not only in enhancing efficiency,but also in ensuring reproducibility of perovskite solar cell characterization.展开更多
Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transit...Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich cathodes.展开更多
Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In th...Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In this study,tea polyphenolpolyvinyl alcohol(TP-PVA)composite films are synthesized via a polymer embedding method and employed as SAs to initiate ultrafast pulse operation in fiber lasers.The TP-PVA SA film exhibits excellent broadband saturable absorption performance at wavelengths of 1.0μm,1.5μm,and 2.0μm,with modulation depths of 54.21%,41.41%,and 51.16%,respectively.Stable passively mode-locked pulses with pulse widths of 588 fs,419 fs,and 743 fs are generated in Yb-,Er-,and Tm-doped fiber lasers,respectively.This work confirms the effective performance of TP-PVA as a broadband SA,and establishes a foundation for the integration of novel and sustainable materials within ultrafast photonic systems.The approach paves the way for developing compact broadband ultrafast laser systems operating in the near-infrared spectral region.展开更多
We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating sli...We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating slit mechanism,a 3D symmetric spherical focal field distribution is created in the laser-irradiated regions of transparent substrates.The corresponding focal field distribution is theoretically calculated and validated by examining the features of laser-inscribed lines in glass samples.Moreover,we investigate the influences of laser writing speed and slit rotational speed on the fabrication resolution in glass,and discuss the formation mechanism of the generated periodic microstructures.To showcase its powerful capability for3D isotropic fabrication,the high-speed rotating slit beam shaping method is applied to create straight optical waveguides,bending optical waveguides,and hollow microchannels in the glass.The proposed method holds great potential for the facile manufacture of diverse 3D isotropic microstructures and devices within transparent materials across various applications,including advanced photonics,microoptics,micro-electromechanical systems,and microfluidics.展开更多
Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the...Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the high spatial resolution and sparsity of multi-path channels,DAM effectively mitigates Inter-Symbol Interference(ISI)by aligning all multi-path components through a combination of delay pre-compensation(or post-compensation)and path-based beamforming.As such,ISI is eliminated while preserving multi-path power gains.In this paper,we investigate multi-user double-side DAM,which incorporates both delay pre-compensation at the transmitter and post-compensation at the receiver,in contrast to prior works that primarily focus on singleside DAM with only delay pre-compensation.Firstly,we derive the constraint on the number of introduced delays and formulate the corresponding delay pre/post-compensation vectors tailored for multi-user double-side DAM,given a specific number of delay compensations.Furthermore,we demonstrate that when the number of Base Stations(BSs)/User Equipment(UE)antennas is sufficiently large,single-side DAM—where delay compensation is performed only at the BS/UE—is preferable to double-side DAM,since the former results in less ISI to be spatially eliminated.Next,we propose two low-complexity path-based beamforming strategies based on the eigen-beamforming transmission and ISI-Zero Forcing(ZF),respectively.On this basis,we further analyze the achievable sum rates.Simulation results verify that with a sufficiently large number of BS/UE antennas,singleside DAM is adequate for ISI elimination.Moreover,compared to the benchmarking scheme of Orthogonal Frequency Division Multiplexing(OFDM),multi-user BS-side DAM achieves higher spectral efficiency and lower Peak-to-Average Power Ratio(PAPR).展开更多
Aqueous zinc-ion batteries(AZIBs)offer promising safety and affordability,but suffer from dendritic Zn growth and parasitic side reactions at the electrode-electrolyte interface.Herein,we construct a dual-region inter...Aqueous zinc-ion batteries(AZIBs)offer promising safety and affordability,but suffer from dendritic Zn growth and parasitic side reactions at the electrode-electrolyte interface.Herein,we construct a dual-region interfacial modulation framework by molecularly reconfiguring the Helmholtz double layer via trace methyl methacrylate(MMA).Exploiting its amphiphilic and functionally asymmetric architecture,MMA enables a coordinated interfacial reconstruction that disrupts Zn^(2+)solvation in the outer Helmholtz plane,builds a chemisorbed coordination layer in the inner plane,and modulates local interfacial chemistry with spatial precision.This dualregion regulation collectively suppresses water reactivity,facilitates Zn^(2+)desolvation,and drives crystallo-graphically preferred deposition along the(101)plane,promoting lateral growth and mitigating dendrite for-mation.As a result,symmetric Zn||Zn cells exhibit over 4200 h of stable cycling at 1 mA cm^(-2) and maintain 1100 h of operation at 2 mA cm^(-2),even at 0℃.Zn||Ti half-cells achieve a Coulombic efficiency of 99.83%,while Zn||NH_(4)V_(4)O_(10) full cells deliver 93.92%capacity retention after 400 cycles at 2 A g^(-1),and preserve 85.3%after 300 cycles at 0℃.This work demonstrates a scalable,mechanism-driven electrolyte design paradigm for dendrite-free and high-performance aqueous Zn metal batteries.展开更多
Epidemiological studies have highlighted an association between periodontitis and osteoporosis.However,the mechanism underlining this association remains unclear.Here,we revealed significant differences in the salivar...Epidemiological studies have highlighted an association between periodontitis and osteoporosis.However,the mechanism underlining this association remains unclear.Here,we revealed significant differences in the salivary microbiota between periodontally healthy individuals and periodontitis patients,with periodontitis patients exhibiting increased salivary microbiota diversity and an elevated abundance of pathogenic bacteria.Using an ovariectomized(OVX) mouse model,we demonstrated that the salivary microbiota from periodontitis patients exacerbated bone destruction by modulating the gut microbiota.Metabolomic analysis revealed that the periodontitis-associated salivary microbiota suppressed tryptophan metabolism.The tryptophan metabolite indole-3-lactic acid(ILA) directly inhibited osteoclast formation and differentiation.In OVX mice treated with periodontitis salivary microbiota,supplementation with ILA effectively suppressed osteoclastogenesis and alleviated the detrimental effects of periodontitis-associated salivary microbiota on systemic bones.In summary,our data demonstrate that periodontitis can affect systemic bone metabolism via the oral-gut axis and that ILA supplementation serves as a potential therapeutic option to mitigate these adverse effects.展开更多
The 200 Gbit/s passive optical network(PON)is most likely to be the next-generation scheme following 50G PON.The costeffective direct detection(DD)system is the economical choice.However,larger-capacity DD systems wil...The 200 Gbit/s passive optical network(PON)is most likely to be the next-generation scheme following 50G PON.The costeffective direct detection(DD)system is the economical choice.However,larger-capacity DD systems will face much more serious power fading caused by chromatic dispersion(CD)combined with square-law DD and thereby significantly increases the complexity of equalization algorithms.In this paper,a 200 Gbit/s Nyquist 4-level pulse amplitude modulation(PAM4)single side-band(SSB)modulation-DD downlink scheme is designed,and a low complexity quadratic-nonlinear equalizer is proposed for this system.The computational complexity of the quadratic nonlinear equalizer is about 28%of that of the conventional Volterra nonlinear equalizer,while still exhibiting excellent nonlinear equalization ability.Simulation results for the 200 Gbit/s system with 20 km fiber transmission show that it can achieve a power budget of 29 dB,while a 30.4 dB power budget is obtained in the 50 Gbit/s experimental transmission.展开更多
Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apop...Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apoptosis,and oxidative stress,play an important role in the onset and progression of stroke.With a better understanding of the critical role of mitochondrial dysfunction modulations in post-stroke neurological injury,these modulations have emerged as a potential target for stroke prevention and treatment.Additionally,since effective treatments for stroke are extremely limited and natural products currently offer some outstanding advantages,we focused on the findings and mechanisms of action related to the use of natural products for targeting mitochondrial dysfunction in the treatment of stroke.Natural products achieve neuroprotective through multi-target regulation of mitochondrial dysfunction encompassing the following processes:(1)Mitochondrial biogenesis:Cordyceps and hydroxysafflor yellow A activate the peroxisome proliferator-activated receptor gamma coactivator 1-alpha/nuclear respiratory factor pathway,promote mitochondrial DNA replication and respiratory chain protein synthesis,and thereby restore energy supply in the ischemic penumbra.(2)Mitochondrial dynamics balance:Ginsenoside Rb3 promotes Opa1-mediated neural stem cell migration and diffusion for recovery of damaged brain tissue.(3)Mitochondrial autophagy:Gypenoside XVII selectively eliminates damaged mitochondria via the phosphatase and tensin homolog-induced kinase 1/Parkin pathway and blocks reactive oxygen species and the NOD-like receptor protein 3 inflammasome cascade,thereby alleviating blood-brain barrier damage.(4)Anti-apoptotic mechanisms:Ginkgolide K inhibits Bax mitochondrial translocation and downregulates caspase-3/9 activity,reducing neuronal programmed death induced by ischemia-reperfusion.(5)Oxidative stress regulation:Scutellarin exerts antioxidant properties and improves neurological function by modulating the extracellular signal-regulated kinase 5-Kruppel-like factor 2-endothelial nitric oxide synthase signaling pathway.(6)Intercellular mitochondrial transport:Neuroprotective effects of Chrysophanol are associated with accelerated mitochondrial transfer from astrocytes to neurons.Existing studies have confirmed that natural products exhibit neuroprotective effects through multidimensional interventions targeting mitochondrial dysfunction in both ischemic and hemorrhagic stroke models.However,their clinical translation still faces challenges,such as the difficulty in standardization due to component complexity,insufficient cross-regional clinical data,and the lack of long-term safety evaluations.Future research should aim to integrate new technologies,such as single-cell sequencing and organoid models,to deeply explore the mitochondria-targeting mechanisms of natural products and validate their efficacy through multicenter clinical trials,providing theoretical support and translational pathways for the development of novel anti-stroke drugs.展开更多
Under the background of‘the Belt and Road’and‘China-Mongolia-Russia Economic Corridor’initiatives,this paper studied the urban accessibility level,regional accessibility pattern and regional spatial effects along ...Under the background of‘the Belt and Road’and‘China-Mongolia-Russia Economic Corridor’initiatives,this paper studied the urban accessibility level,regional accessibility pattern and regional spatial effects along the Primorsky No.1 and No.2 transportation corridors.First,the evaluation of urban accessibility level with and without Primorsky No.1 and No.2 high-speed rails(HSRs)opening was conducted with two indicators,i.e.,the weighted average travel time,and the economic potential.After the evaluation,the spatial differentiation pattern of the accessibility changes with and without Primorsky No.1 and No.2 HSRs opening was performed respectively using ArcGIS.On these bases,the regional spatial effects brought by Primorsky No.1 and No.2 HSRs opening were studied.The results are as following.First,the urban accessibility level will be greatly improved by the opening of Primorsky No.1 and No.2 HSRs.All adjacent cities will be integrated into‘1 h HSR communication circle’and the whole journey will be integrated into‘4 h HSR communication circle’along Primorsky No.1 and No.2 corridors,respectively.The HSR accessibility of Primorsky No.1 corridor is stronger than that of Primorsky No.2 corridor.But the HSR accessibility improvement degree of Primorsky No.1 corridor is weaker than that of Primorsky No.2 corridor.Second,spatially,along Primorsky No.1 and No.2 corridors,the HSR accessibility level of the cities which are located in China is stronger than those cities located in Russia,showing the‘High West,Low East’patterns.The HSR accessibility improvement degree of the cities which are located in Russia and Sino-Russian border is stronger than those cities located in China,showing the‘High East,Low West’patterns.Third,Primorsky No.1 and No.2 corridors could connect the China’s‘Heilongjiang Land Sea Silk Road Economic Belt’and‘Changchun-Jilin-Tumen Development Pilot Zone’respectively,gradually involving into the development of China’s Harbin-Changchun Megalopolis.Relying on Harbin(China)and Changchun(China),Primorsky No.1 and No.2 HSRs could connect Northeast China-Beijing HSR,accelerating the diffusion of population,economy and other flows from China’s Beijing-Tianjin-Hebei Urban Agglomeration to Northeast China,and then to Russia’s Far East Federal District.Relying on Suifenhe(China)and Hunchun(China),Primorsky No.1 and No.2 HSRs could be conducive to the development of the second largest sea channels for Northeast China,creating the Northeast Asian Urban Belt,and new sea-rail intermodal pattern among China,Russia,Democratic People’s Republic of Korea,Japan and Republic of Korea.Relying on Vladivostok(Russia)and Zarubino(Russia),Primorsky No.1 and No.2 corridors could connect the‘Ice Silk Road’,building the‘Sino-Russian Northern Maritime Corridor’and‘Sino-Russian Arctic Blue Economic Areas’.展开更多
Currently,the global 5G network,cloud computing,and data center industries are experiencing rapid development.The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transce...Currently,the global 5G network,cloud computing,and data center industries are experiencing rapid development.The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transceivers for optical interconnection within data centers.The electro-absorption modulated laser(EML),which is widely used in optical fiber communications,data centers,and high-speed data transmission systems,represents a high-performance photoelectric conversion device.Compared to traditional directly modulated lasers(DMLs),EMLs demonstrate lower frequency chirp and higher modulation bandwidth,enabling support for higher data rates and longer transmission distances.This article introduces the composition,working principles,manufacturing processes,and applications of EMLs.It reviews the progress on advanced indium phosphide(InP)-based EML devices from research institutions worldwide,while summarizing and comparing data transmission rates and key technical approaches across various studies.展开更多
erized by a periodic real-space modulation of the superconducting pairing order parameter,is a novel quantum phase observed in superconducting(SC)systems.It is believed to play a key role in understanding the pseudoga...erized by a periodic real-space modulation of the superconducting pairing order parameter,is a novel quantum phase observed in superconducting(SC)systems.It is believed to play a key role in understanding the pseudogap phase of superconductors and has recently been discovered in bulk cuprates,transition-metal dichalcogenide,and other unconventional superconductors.However,artificially engineered PDW in designable two-dimensional materials remain rare.In this paper,we report a strain-assisted strategy to realize cooper-pair density modulation in a van der Waals heterostructure:graphene on SC 2H-NbSe2.Superconductivity is induced in graphene via the proximity effect.Meanwhile,the graphene membrane spontaneously buckles into a periodic structure owing to strain,featuring a spatially modulated local density of states(LDOS).The interplay between the spatially modulated LDOS and the proximity-induced superconductivity results in an oscillatory pair density determined by the buckled geometry,constituting an artificial PDW.This approach enables the engineering of PDWs with periodicities of up to tens of nanometers and allows their realization in a variety of heterostructures with tailored designs.Our work provides new insights into the investigation of PDW physics using predesigned two-dimensional materials.展开更多
基金supported in part by National Natural Science Foundation of China under Grant 62461024Jiangxi Provincial Natural Science Foundation of China under Grant 20224ACB202001.
文摘In high-speed railway(HSR)wireless communication,the rapid channel changes and limited high-capacity access cause significant impact on the link performance.Meanwhile,the Doppler shift caused by high mobility leads to the inter-carrier interference.In this paper,we propose a reconfigurable intelligent surface(RIS)-assisted receive spatial modulation(SM)scheme based on the spatial-temporal correlated HSR Rician channel.The characteristics of SM and the phase shift adjustment of RIS are used to mitigate the performance degradation in high mobility scenarios.Considering the influence of channel spatial-temporal correlation and Doppler shift,the effects of different parameters on average bit error rate(BER)performance and upper bound of ergodic capacity are analyzed.Therefore,a joint antenna and RIS-unit selection algorithm based on the antenna removal method is proposed to increase the capacity performance of communication links.Numerical results show that the proposed RIS-assisted receive SM scheme can maintain high transmission capacity compared to the conventional HSR-SM scheme,whereas the degradation of BER performance can be compensated by arranging a large number of RIS-units.In addition,selecting more RIS-units has better capacity performance than activating more antennas in the low signal-to-noise ratio regions.
基金National Natural Science Foundation of China(12405168)The Fundamental Research Funds for the Central Universities,China(2024CDJXY004)。
文摘[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.
基金supported by the National Natural Science Foundation of China(Nos.12261131505,U2241274)the Russian Science Fund(No.23-49-00133)+3 种基金the Aeronautical Science Foundation of China(No.20240002053002)the Natural Science Basic Research Program of Shaanxi,China(No.2025JC-YBMS-005)the Key Research and Development Program of Shaanxi,China(No.2024GX-YBXM-037)the Basic Research Programs of Taicang,China(No.TC2024JC10)。
文摘As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure the performance protection requirements.In order to clarify the rain erosion damage mechanism of radome coating and explore the influencing factors and mechanisms of coating material damage under different jet impact conditions,impact tests were conducted on three types of skin coating samples,and the damage mode was observed through electron microscopy characterization.The experimental results show that the typical morphology of rain erosion damage is annular surface peeling damage.The damage area and volume of the three coating samples increase with the continuous increase of raindrop impact velocity.The threshold velocity for initial damage to the coating is about 360 m/s;under the influence of the velocity component,the reduction in impact angle leads to a gradual reduction in the degree of damage to the sample.ABAQUS finite element simulation software was used to establish a constitutive model for coating rain erosion simulation and obtain the propagation law of stress waves during the impact process.The simulation results show that at the 75°impact angle,the jet impacts the surface of the specimen at different velocities,and as the impact velocity increases,the Mises equivalent stress on the surface shows an increasing trend,which is one of the main factors causing damage with increasing velocity.The effectiveness,rain erosion damage mode,and influencing mechanism of the model were verified based on the test results;the dynamic failure mechanism of the sample was further studied,and the stress propagation process at different impact angles was compared,revealing the influence mechanism and damage law of the impact angle on the high-speed raindrop impact of the material.
文摘This paper studies the structural response of high-speed train wipers under the combined action of complex flow fields and scraping actions.The stress concentration areas are determined through simulation analysis,and the stress and aerodynamic load measurement points are reasonably arranged accordingly.The actual measurement is carried out in combination with the operating conditions of the existing lines.The stress variations and spectral characteristics of the train under different speed levels(80,160,180,200 km/h),tunnel entry and exit,and scraper action conditions were compared and analyzed.The stress amplification factors under tunnel intersection and scraper action were obtained,providing boundary conditions for the design of wipers for highspeed s.The research results show that the maximum stress of the wiper structure obtained through simulation calculation is concentrated at the connection of the wiper arm.Structural stress increases with the rise of speed grade.The stress increases by 1.11 times when the tunnel meets.When the scraper operates,the stress on the scraper arm increases by 4.1–7.6 times.Due to the broadband excitation effect of the aerodynamic load,the spectral energy of the structure is relatively high at the natural frequency,which excites the natural mode of the wiper.
基金funding from the National Key Research and Development Program of China(No.2018YFE0110000)the National Natural Science Foundation of China(No.11274259,No.11574258)the Science and Technology Commission Foundation of Shanghai(21DZ1205500)in support of the present research.
文摘While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.
文摘Research on high-speed railways is a relatively new yet highly significant field in Vietnam.Among its key components,train control signaling plays a critical role,as it directly affects various interconnected systems,including infrastructure,traction power supply,operational planning,and overall railway safety.This article focuses on evaluating the capacity of the line based on the types of signals suitable for high-speed railways that have been effectively implemented in several European countries and successfully adapted in China.The research and simulation are conducted using MATLAB software,a reliable and widely adopted tool in the scientific community.The findings demonstrate that under normal conditions,the European Railway Traffic Management System/European Train Control System(ERTMS/ETCS)Level 2 signaling can support up to 23.7485 trains/hour/direction.Meanwhile,ERTMS/ETCS Level 3 with full moving block can accommodate up to 30.8735 trains/hour/direction,and ERTMS/ETCS Level 3 with fixed virtual blocks up to 29.4694 trains/hour/direction.In emergency scenarios,ERTMS/ETCS Level 3 with full moving block reduces headway by 33.27%compared to CTCS Level 3,while ERTMS/ETCS Level 3 with fixed virtual blocks achieves a 28.78%reduction.Overall,the ERTMS/ETCS Level 3 emerges as a state-of-the-art signaling technology offering high capacity and operational efficiency,and is recommended as a forward-looking solution for future implementation in Vietnam.
基金sponsored by the National Natural Science Foundation of China(Grant No.52178100).
文摘The spatial offset of bridge has a significant impact on the safety,comfort,and durability of high-speed railway(HSR)operations,so it is crucial to rapidly and effectively detect the spatial offset of operational HSR bridges.Drive-by monitoring of bridge uneven settlement demonstrates significant potential due to its practicality,cost-effectiveness,and efficiency.However,existing drive-by methods for detecting bridge offset have limitations such as reliance on a single data source,low detection accuracy,and the inability to identify lateral deformations of bridges.This paper proposes a novel drive-by inspection method for spatial offset of HSR bridge based on multi-source data fusion of comprehensive inspection train.Firstly,dung beetle optimizer-variational mode decomposition was employed to achieve adaptive decomposition of non-stationary dynamic signals,and explore the hidden temporal relationships in the data.Subsequently,a long short-term memory neural network was developed to achieve feature fusion of multi-source signal and accurate prediction of spatial settlement of HSR bridge.A dataset of track irregularities and CRH380A high-speed train responses was generated using a 3D train-track-bridge interaction model,and the accuracy and effectiveness of the proposed hybrid deep learning model were numerically validated.Finally,the reliability of the proposed drive-by inspection method was further validated by analyzing the actual measurement data obtained from comprehensive inspection train.The research findings indicate that the proposed approach enables rapid and accurate detection of spatial offset in HSR bridge,ensuring the long-term operational safety of HSR bridges.
基金financially supported by the Swedish Transport Administration(Trafikverket)through the“Excellence Area 4”and FOI-BBT program(Grant Nos.BBT-2019-022 and BBT-TRV 2024/132497).
文摘Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may compromise their fatigue capacity.The most common structural design for railway noise barriers consists of vertical configurations of posts and panels.However,there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads.This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers.Analysis of a 40-m-long noise barrier model and a triangular simplified load model,the latter of which effectively represented the detailed aerodynamic load,were first used to establish the model and input of the moving load during dynamic simulation.Then,the effects of different parameters on the dynamic response of the noise barrier were evaluated,including the damping ratio,the profile of the steel post,the span length of the panel,the barrier height,and the train speed.Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses,followed by train speed,post profile,span length,and damping ratio.A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves.The dynamic amplification factor(DAF)was found to be related to both the natural frequency and train speed.A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-NR076521,RS-2025-00519481)the Research Grant of Kwangwoon University in 2023.
文摘The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet the mechanisms underlying these antithetical behaviors are still under investigation.In this study,we explore the modulation of the open-circuit voltage(Voc)in triple-cation mixed-halide perovskite solar cells by systematically controlling storage environments.While light intensity exhibits minimal impact during storage,the spectral composition of illumination selectively enhances Voc comprising reversible and irreversible contributions.Structural characterization reveals that prolonged storage degrades the quality of perovskite crystals in the upper region of the perovskite layer,whereas light storage promotes the relaxation of microstrain at the buried interface with a p-type organic layer.This structural reorganization at the interface,accompanied by lattice expansion,accounts for suppressed nonradiative recombination and a corresponding increase in quasi-Fermi level splitting.Consequently,devices fabricated without chemical defect passivation achieve a power conversion efficiency of higher than 40%under indoor lighting conditions after preconditioned by continuous exposure to ambient light during storage.These findings highlight the critical role of controlled light exposure during storage not only in enhancing efficiency,but also in ensuring reproducibility of perovskite solar cell characterization.
基金support from National Key R&D Program of China(2022YFB3807200)Science and Technology Commission of Shanghai Municipality(25CL2902100).
文摘Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich cathodes.
基金supported by the Opening Foundation of Hubei Key Laboratory for New Textile Materials and Applications Research(Grant No.FZXCL202410)the Key Project of Science and Technology Research Program of Hubei Provincial Department of Education,China(Grant No.D20231704)+1 种基金Wuhan Textile University(Grant No.523058)the Foundation of Wuhan Textile University(Grant No.K24058)。
文摘Materials exhibiting broadband nonlinear optical responses are critically important for ultrafast photonics applications,particularly as saturable absorbers(SAs)that facilitate broadband optical pulse generation.In this study,tea polyphenolpolyvinyl alcohol(TP-PVA)composite films are synthesized via a polymer embedding method and employed as SAs to initiate ultrafast pulse operation in fiber lasers.The TP-PVA SA film exhibits excellent broadband saturable absorption performance at wavelengths of 1.0μm,1.5μm,and 2.0μm,with modulation depths of 54.21%,41.41%,and 51.16%,respectively.Stable passively mode-locked pulses with pulse widths of 588 fs,419 fs,and 743 fs are generated in Yb-,Er-,and Tm-doped fiber lasers,respectively.This work confirms the effective performance of TP-PVA as a broadband SA,and establishes a foundation for the integration of novel and sustainable materials within ultrafast photonic systems.The approach paves the way for developing compact broadband ultrafast laser systems operating in the near-infrared spectral region.
基金supported by the National Key Research and Development Program of China(2022YFA1404800)National Natural Science Foundation of China(12174107,12004221,12192254,92250304,W2441005,12334014,12192251)+4 种基金Natural Science Foundation of Shandong Province(ZR2024QA024,ZR2021ZD02)Postdoctoral Innovation Talents Support Program of Shandong Province(No.SDBX2019005)Shanghai Municipal Science and Technology Major ProjectFundamental Research Funds for the Central UniversitiesEngineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(No.2023nmc005)。
文摘We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating slit mechanism,a 3D symmetric spherical focal field distribution is created in the laser-irradiated regions of transparent substrates.The corresponding focal field distribution is theoretically calculated and validated by examining the features of laser-inscribed lines in glass samples.Moreover,we investigate the influences of laser writing speed and slit rotational speed on the fabrication resolution in glass,and discuss the formation mechanism of the generated periodic microstructures.To showcase its powerful capability for3D isotropic fabrication,the high-speed rotating slit beam shaping method is applied to create straight optical waveguides,bending optical waveguides,and hollow microchannels in the glass.The proposed method holds great potential for the facile manufacture of diverse 3D isotropic microstructures and devices within transparent materials across various applications,including advanced photonics,microoptics,micro-electromechanical systems,and microfluidics.
基金supported in part by the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province under Grant BK20240070in part by the National Natural Science Foundation of China under Grant 62071114n part by the Fundamental Research Funds for the Central Universities under Grant 2242022k60004。
文摘Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the high spatial resolution and sparsity of multi-path channels,DAM effectively mitigates Inter-Symbol Interference(ISI)by aligning all multi-path components through a combination of delay pre-compensation(or post-compensation)and path-based beamforming.As such,ISI is eliminated while preserving multi-path power gains.In this paper,we investigate multi-user double-side DAM,which incorporates both delay pre-compensation at the transmitter and post-compensation at the receiver,in contrast to prior works that primarily focus on singleside DAM with only delay pre-compensation.Firstly,we derive the constraint on the number of introduced delays and formulate the corresponding delay pre/post-compensation vectors tailored for multi-user double-side DAM,given a specific number of delay compensations.Furthermore,we demonstrate that when the number of Base Stations(BSs)/User Equipment(UE)antennas is sufficiently large,single-side DAM—where delay compensation is performed only at the BS/UE—is preferable to double-side DAM,since the former results in less ISI to be spatially eliminated.Next,we propose two low-complexity path-based beamforming strategies based on the eigen-beamforming transmission and ISI-Zero Forcing(ZF),respectively.On this basis,we further analyze the achievable sum rates.Simulation results verify that with a sufficiently large number of BS/UE antennas,singleside DAM is adequate for ISI elimination.Moreover,compared to the benchmarking scheme of Orthogonal Frequency Division Multiplexing(OFDM),multi-user BS-side DAM achieves higher spectral efficiency and lower Peak-to-Average Power Ratio(PAPR).
基金supported by the National Natural Science Foundation of China(Grant Nos.52125405 and U22A20108)Thailand Science Research and Innovation Fund Chulalongkorn University,National Research Council of Thailand(NRCT)and Chulalongkorn University(N42A660383).D.D.Zhang would like to thank the financial support from the Scientific Research Fund of Liaoning Provincial Education Department of China(No.JYTQN2023289)+3 种基金Liaoning Provincial Science and Technology Joint Plan(Fund)Project(No.2023-BSBA-259)and the opening project of State Key Laboratory of Metastable Materials Science and Technology,Yanshan University(No.202404).J.Cao would like to acknowledge the support from National Natural Science Foundation of China(Grant No.52402279)China Postdoctoral Science Foundation Special Funding(Grant Nos.2025T180002,2024M751753)the opening project of State Key Laboratory of Metastable Materials Science and Technology(Yanshan University)(No.202401).
文摘Aqueous zinc-ion batteries(AZIBs)offer promising safety and affordability,but suffer from dendritic Zn growth and parasitic side reactions at the electrode-electrolyte interface.Herein,we construct a dual-region interfacial modulation framework by molecularly reconfiguring the Helmholtz double layer via trace methyl methacrylate(MMA).Exploiting its amphiphilic and functionally asymmetric architecture,MMA enables a coordinated interfacial reconstruction that disrupts Zn^(2+)solvation in the outer Helmholtz plane,builds a chemisorbed coordination layer in the inner plane,and modulates local interfacial chemistry with spatial precision.This dualregion regulation collectively suppresses water reactivity,facilitates Zn^(2+)desolvation,and drives crystallo-graphically preferred deposition along the(101)plane,promoting lateral growth and mitigating dendrite for-mation.As a result,symmetric Zn||Zn cells exhibit over 4200 h of stable cycling at 1 mA cm^(-2) and maintain 1100 h of operation at 2 mA cm^(-2),even at 0℃.Zn||Ti half-cells achieve a Coulombic efficiency of 99.83%,while Zn||NH_(4)V_(4)O_(10) full cells deliver 93.92%capacity retention after 400 cycles at 2 A g^(-1),and preserve 85.3%after 300 cycles at 0℃.This work demonstrates a scalable,mechanism-driven electrolyte design paradigm for dendrite-free and high-performance aqueous Zn metal batteries.
基金provided by the National Natural Sciences Foundation of China (82270979)High-Level Hospital Construction Project (0224C001,0224C050)Cultivation Program for Reserve Talents for Academic Leaders (2023A208) of Nanjing Stomatological Hospital,Affiliated Hospital of Medical School,Institute of Stomatology,Nanjing University。
文摘Epidemiological studies have highlighted an association between periodontitis and osteoporosis.However,the mechanism underlining this association remains unclear.Here,we revealed significant differences in the salivary microbiota between periodontally healthy individuals and periodontitis patients,with periodontitis patients exhibiting increased salivary microbiota diversity and an elevated abundance of pathogenic bacteria.Using an ovariectomized(OVX) mouse model,we demonstrated that the salivary microbiota from periodontitis patients exacerbated bone destruction by modulating the gut microbiota.Metabolomic analysis revealed that the periodontitis-associated salivary microbiota suppressed tryptophan metabolism.The tryptophan metabolite indole-3-lactic acid(ILA) directly inhibited osteoclast formation and differentiation.In OVX mice treated with periodontitis salivary microbiota,supplementation with ILA effectively suppressed osteoclastogenesis and alleviated the detrimental effects of periodontitis-associated salivary microbiota on systemic bones.In summary,our data demonstrate that periodontitis can affect systemic bone metabolism via the oral-gut axis and that ILA supplementation serves as a potential therapeutic option to mitigate these adverse effects.
基金ZTE Industry-University-Institute Cooperation Funds under Grant No.HC-CN-20230105001National Natural Science Foundation of China under Grant No.62001045。
文摘The 200 Gbit/s passive optical network(PON)is most likely to be the next-generation scheme following 50G PON.The costeffective direct detection(DD)system is the economical choice.However,larger-capacity DD systems will face much more serious power fading caused by chromatic dispersion(CD)combined with square-law DD and thereby significantly increases the complexity of equalization algorithms.In this paper,a 200 Gbit/s Nyquist 4-level pulse amplitude modulation(PAM4)single side-band(SSB)modulation-DD downlink scheme is designed,and a low complexity quadratic-nonlinear equalizer is proposed for this system.The computational complexity of the quadratic nonlinear equalizer is about 28%of that of the conventional Volterra nonlinear equalizer,while still exhibiting excellent nonlinear equalization ability.Simulation results for the 200 Gbit/s system with 20 km fiber transmission show that it can achieve a power budget of 29 dB,while a 30.4 dB power budget is obtained in the 50 Gbit/s experimental transmission.
基金supported by the National Natural Science Foundation of China,No.82204663(to TZ)the Natural Science Foundation of Shandong Province,No.ZR2022QH058(to TZ).
文摘Modulations of mitochondrial dysfunction,which involve a series of dynamic processes such as mitochondrial biogenesis,mitochondrial fusion and fission,mitochondrial transport,mitochondrial autophagy,mitochondrial apoptosis,and oxidative stress,play an important role in the onset and progression of stroke.With a better understanding of the critical role of mitochondrial dysfunction modulations in post-stroke neurological injury,these modulations have emerged as a potential target for stroke prevention and treatment.Additionally,since effective treatments for stroke are extremely limited and natural products currently offer some outstanding advantages,we focused on the findings and mechanisms of action related to the use of natural products for targeting mitochondrial dysfunction in the treatment of stroke.Natural products achieve neuroprotective through multi-target regulation of mitochondrial dysfunction encompassing the following processes:(1)Mitochondrial biogenesis:Cordyceps and hydroxysafflor yellow A activate the peroxisome proliferator-activated receptor gamma coactivator 1-alpha/nuclear respiratory factor pathway,promote mitochondrial DNA replication and respiratory chain protein synthesis,and thereby restore energy supply in the ischemic penumbra.(2)Mitochondrial dynamics balance:Ginsenoside Rb3 promotes Opa1-mediated neural stem cell migration and diffusion for recovery of damaged brain tissue.(3)Mitochondrial autophagy:Gypenoside XVII selectively eliminates damaged mitochondria via the phosphatase and tensin homolog-induced kinase 1/Parkin pathway and blocks reactive oxygen species and the NOD-like receptor protein 3 inflammasome cascade,thereby alleviating blood-brain barrier damage.(4)Anti-apoptotic mechanisms:Ginkgolide K inhibits Bax mitochondrial translocation and downregulates caspase-3/9 activity,reducing neuronal programmed death induced by ischemia-reperfusion.(5)Oxidative stress regulation:Scutellarin exerts antioxidant properties and improves neurological function by modulating the extracellular signal-regulated kinase 5-Kruppel-like factor 2-endothelial nitric oxide synthase signaling pathway.(6)Intercellular mitochondrial transport:Neuroprotective effects of Chrysophanol are associated with accelerated mitochondrial transfer from astrocytes to neurons.Existing studies have confirmed that natural products exhibit neuroprotective effects through multidimensional interventions targeting mitochondrial dysfunction in both ischemic and hemorrhagic stroke models.However,their clinical translation still faces challenges,such as the difficulty in standardization due to component complexity,insufficient cross-regional clinical data,and the lack of long-term safety evaluations.Future research should aim to integrate new technologies,such as single-cell sequencing and organoid models,to deeply explore the mitochondria-targeting mechanisms of natural products and validate their efficacy through multicenter clinical trials,providing theoretical support and translational pathways for the development of novel anti-stroke drugs.
基金Under the auspices of Heilongjiang Provincial Natural Science Foundation of China(No.YQ2024D012),National Natural Science Foundation of China(No.42071162,42101165,42501220)。
文摘Under the background of‘the Belt and Road’and‘China-Mongolia-Russia Economic Corridor’initiatives,this paper studied the urban accessibility level,regional accessibility pattern and regional spatial effects along the Primorsky No.1 and No.2 transportation corridors.First,the evaluation of urban accessibility level with and without Primorsky No.1 and No.2 high-speed rails(HSRs)opening was conducted with two indicators,i.e.,the weighted average travel time,and the economic potential.After the evaluation,the spatial differentiation pattern of the accessibility changes with and without Primorsky No.1 and No.2 HSRs opening was performed respectively using ArcGIS.On these bases,the regional spatial effects brought by Primorsky No.1 and No.2 HSRs opening were studied.The results are as following.First,the urban accessibility level will be greatly improved by the opening of Primorsky No.1 and No.2 HSRs.All adjacent cities will be integrated into‘1 h HSR communication circle’and the whole journey will be integrated into‘4 h HSR communication circle’along Primorsky No.1 and No.2 corridors,respectively.The HSR accessibility of Primorsky No.1 corridor is stronger than that of Primorsky No.2 corridor.But the HSR accessibility improvement degree of Primorsky No.1 corridor is weaker than that of Primorsky No.2 corridor.Second,spatially,along Primorsky No.1 and No.2 corridors,the HSR accessibility level of the cities which are located in China is stronger than those cities located in Russia,showing the‘High West,Low East’patterns.The HSR accessibility improvement degree of the cities which are located in Russia and Sino-Russian border is stronger than those cities located in China,showing the‘High East,Low West’patterns.Third,Primorsky No.1 and No.2 corridors could connect the China’s‘Heilongjiang Land Sea Silk Road Economic Belt’and‘Changchun-Jilin-Tumen Development Pilot Zone’respectively,gradually involving into the development of China’s Harbin-Changchun Megalopolis.Relying on Harbin(China)and Changchun(China),Primorsky No.1 and No.2 HSRs could connect Northeast China-Beijing HSR,accelerating the diffusion of population,economy and other flows from China’s Beijing-Tianjin-Hebei Urban Agglomeration to Northeast China,and then to Russia’s Far East Federal District.Relying on Suifenhe(China)and Hunchun(China),Primorsky No.1 and No.2 HSRs could be conducive to the development of the second largest sea channels for Northeast China,creating the Northeast Asian Urban Belt,and new sea-rail intermodal pattern among China,Russia,Democratic People’s Republic of Korea,Japan and Republic of Korea.Relying on Vladivostok(Russia)and Zarubino(Russia),Primorsky No.1 and No.2 corridors could connect the‘Ice Silk Road’,building the‘Sino-Russian Northern Maritime Corridor’and‘Sino-Russian Arctic Blue Economic Areas’.
基金supported by the Strategic Priority Research Program of CAS(Grant No.XDB43020202)the Natural Science Foundation of China(Grant Nos.61934007,62274153,62090053).
文摘Currently,the global 5G network,cloud computing,and data center industries are experiencing rapid development.The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transceivers for optical interconnection within data centers.The electro-absorption modulated laser(EML),which is widely used in optical fiber communications,data centers,and high-speed data transmission systems,represents a high-performance photoelectric conversion device.Compared to traditional directly modulated lasers(DMLs),EMLs demonstrate lower frequency chirp and higher modulation bandwidth,enabling support for higher data rates and longer transmission distances.This article introduces the composition,working principles,manufacturing processes,and applications of EMLs.It reviews the progress on advanced indium phosphide(InP)-based EML devices from research institutions worldwide,while summarizing and comparing data transmission rates and key technical approaches across various studies.
基金supported by the National Natural Science Foundation of China (Grant Nos.12474477,12550405,and 61888102)the Beijing Outstanding Young Scientist Program+4 种基金the National Key R&D Program of China (Grant No.2024YFA1207700)the Fundamental Research Funds for the Central Universitiesthe Scientific Research Innovation Capability Support Project for Young Faculty (Grant No.SRICSPYF- ZY2025071)the Robotic AI-Scientist Platform of the Chinese Academy of Sciencesfinancial support from the Flemish Research Foundation (Grant Nos.FWO/11E5821N and FWO/G0A5921N)。
文摘erized by a periodic real-space modulation of the superconducting pairing order parameter,is a novel quantum phase observed in superconducting(SC)systems.It is believed to play a key role in understanding the pseudogap phase of superconductors and has recently been discovered in bulk cuprates,transition-metal dichalcogenide,and other unconventional superconductors.However,artificially engineered PDW in designable two-dimensional materials remain rare.In this paper,we report a strain-assisted strategy to realize cooper-pair density modulation in a van der Waals heterostructure:graphene on SC 2H-NbSe2.Superconductivity is induced in graphene via the proximity effect.Meanwhile,the graphene membrane spontaneously buckles into a periodic structure owing to strain,featuring a spatially modulated local density of states(LDOS).The interplay between the spatially modulated LDOS and the proximity-induced superconductivity results in an oscillatory pair density determined by the buckled geometry,constituting an artificial PDW.This approach enables the engineering of PDWs with periodicities of up to tens of nanometers and allows their realization in a variety of heterostructures with tailored designs.Our work provides new insights into the investigation of PDW physics using predesigned two-dimensional materials.
