Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,...Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.展开更多
Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon...Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon-based readout circuits in a single step.Based on this,we propose a photodiode based on an n-i-p structure,which removes the buffer layer and further simplifies the manufacturing process of quantum dot image sensors,thus reducing manufacturing costs.Additionally,for the noise complexity in quantum dot image sensors when capturing images,traditional denoising and non-uniformity methods often do not achieve optimal denoising re⁃sults.For the noise and stripe-type non-uniformity commonly encountered in infrared quantum dot detector imag⁃es,a network architecture has been developed that incorporates multiple key modules.This network combines channel attention and spatial attention mechanisms,dynamically adjusting the importance of feature maps to en⁃hance the ability to distinguish between noise and details.Meanwhile,the residual dense feature fusion module further improves the network's ability to process complex image structures through hierarchical feature extraction and fusion.Furthermore,the pyramid pooling module effectively captures information at different scales,improv⁃ing the network's multi-scale feature representation ability.Through the collaborative effect of these modules,the network can better handle various mixed noise and image non-uniformity issues.Experimental results show that it outperforms the traditional U-Net network in denoising and image correction tasks.展开更多
Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we ...Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we found the boosting effects of halogens on organic pollutants formation during thermal processes.In situ electron paramagnetic resonance spectroscopy was used to distinguish the organic free radical intermediates of organic pollutants during thermal processes.The pure chlorine-containing reaction system dominantly induce the formation of highly chlorinated phenoxy radicals,whereas the pure bromine-containing reaction system induce the formation of semiquinone radicals.The results provide clear evidence for the molecular mechanisms by which halogen coexistence boosts pollutants formation.Coexisting halogens made the reactions much more complex.Bromine atom radicals(Br·)can enhance the level of active chlorine atoms radicals(Cl·),then(1)facilitating highly chlorinated organic radicals and toxic pollutants formation,(2)activating polycyclic aromatic hydrocarbons molecules for subsequent ring growth and(3)accelerating oxidation reactions.Combining the identification of organic free radical intermediates and characteristics of products,detailed mechanisms of halogens on the formations of organic pollutants during thermal-related processes were clarified,which can be helpful for their efficient control in the widespread bromines and chlorines co-existence reaction system.展开更多
Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy(WtE)incineration processes.This study aims to investigate the influenc...Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy(WtE)incineration processes.This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals(EPFRs)from phenolic compounds based on the first-principles calculations.Two oxygen-deficient conditions were considered:oxygen vacancies at the top surface and on the subsurface.Our simulations indicate that the adsorption strength of phenol on theα-Fe_(2)O_(3)(0001)surface is enhanced by the presence of oxygen vacancies.However,the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule,particularly for the surface with a defective point at the top layer.Thermo-kinetic parameters were established over a temperature range of300-1000 K,and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface.The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeⅢto FeⅡ,which lower the oxidizing ability of surface reaction sites.The findings of this study provide us a promising approach to regulate the formation of EPFRs.展开更多
In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to ana...In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to analyze the five failure factors that lead to the failure of the accelerator grid of a 30 cm diameter ion thruster under the working mode of 5 k W.Meanwhile,the acceleration stress levels corresponding to different failure factors are obtained.The results show that background pressure has the highest stress level on the grid's erosion.The accelerator grid aperture's mass sputtering rate under the rated vacuum degree(1×10^(-4)Pa)of 5 k W work mode is 8.78 times that of the baseline vacuum degree(1×10^(-6)Pa),and the mass sputtering rate under worse vacuum degree(5×10^(-3)Pa)is 5.08 times that of 1×10^(-4)Pa.Under the influence of the other four failure factors,namely,the voltage of the accelerator grid,upstream plasma density,the screen grid voltage and mass utilization efficiency,the mass sputtering rates of the accelerator grid hole are 2.32,2.67,1.98 and 2.51 times those of the accelerator grid hole under baseline condition,respectively.The ion sputtering results of two 30 cm diameter ion thrusters(both installed with new grids assembly)after working for 1000 h show that the mass sputtering rate of the accelerator grid hole under vacuum conditions of 5×10^(-3)Pa is 4.54 times that under the condition of 1×10^(-4)Pa,and the comparison error between simulation results and test results of acceleration stress is about 10%.In the subsequent ion thruster lifetime verification,the working vacuum degree can be adjusted according to the acceleration stress level of background pressure,so as to shorten the test time and reduce the test cost.展开更多
The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave...The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.展开更多
Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes.For large-inertia scanning systems,constant-speed scanning requires substantial time to complete the reversal motion,redu...Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes.For large-inertia scanning systems,constant-speed scanning requires substantial time to complete the reversal motion,reducing the system's adaptability to high-speed reversal scanning and decreasing scanning efficiency.This study proposes a novel sinusoidal variable-speed roll scanning strategy,which reduces abrupt changes in speed and acceleration,minimizing time loss during reversals.Based on the forward image motion compensation strategy in the pitch direction,we establish a line-of-sight(LOS)position calculation model with vertical flight path correction(VFPC),ensuring that the central LOS of the scanned image remains stable on the same horizontal line,facilitating accurate image stitching in whisk-broom imaging.Through theoretical analysis and simulation experiments,the proposed method improves the scanning efficiency by approximately 18.6%at a 90o whiskbroom imaging angle under the same speed height ratio conditions.The new VFPC method enables wide-field,high-resolution imaging,achieving single-line LOS horizontal stability with an accuracy of better than O.4 mrad.The research is of great significance to promote the further development of airborne area-array whisk-broom imaging technology toward wider fields of view,higher speed height ratios,and greater scanning efficiency.展开更多
Electrocatalytic water splitting for hydrogen production is a key approach to tackling the current energy crisis.Among the catalysts,the traditional Pd@C catalysts are remarkable for their efficiency in hydrogen evolu...Electrocatalytic water splitting for hydrogen production is a key approach to tackling the current energy crisis.Among the catalysts,the traditional Pd@C catalysts are remarkable for their efficiency in hydrogen evolution.However,the high cost and scarcity of Pd catalysts,as well as the instability caused by the corrosiveness of carbon-based substrates,hinder their large-scale application.To overcome this challenge,an effective strategy is to construct highly dispersed Pd single atoms to improve palladium utilization and choose more stable materials as supports.In this study,TiO_(2-x)carriers with abundant oxygen vacancies were prepared and loaded with Pd by photoreduction deposition.Adjusting the palladium content resulted in three forms of Pd-loaded TiO_(2-x):nanoparticles(Pd@TiO_(2-x)(6%,10%)),nanoclusters(Pd@TiO_(2-x)(3%))and single atoms(Pd@TiO_(2-x)(1.5%)).The oxygen vacancies improved the stability of the titanium dioxide materials by providing more active hydrogen adsorption sites and increasing the affinity of Pd for active hydrogen.Single atom loading increased the frequency of oxygen holes in the support and the high activity of monatomic Pd promoted the adsorption of active hydrogen and facilitated the formation of active hydrogen intermediates.The synergistic effect of single atoms and oxygen vacancies improved the stability and catalytic activity of the composite material.Pd@TiO_(2-x)(1.5%)showed outstanding performance in hydrogen evolution in an acidic medium with an overpotential of only 24 m V at a current density of 10 m A/cm^(2)and a low Tafel rise of 41.9 m V/dec.This study provides an effective strategy for the development of high-performance hydrogen evolution(HER)catalysts.展开更多
Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of...Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of turbulences in the very early universe in sustaining intense and persistent fluctuations in energy or mass density,which could provide a natural mechanism for PBH formation in the primordial universe. We analyze the mass range and abundance of PBHs produced in the magnetohydrodynamic turbulence induced by the electroweak phase transition. Remarkably, we find that the mass range of the produced PBHs falls within the most viable“asteroid mass” window from the present-day observations, and within natural parameter regions their abundance can be sufficiently large. These findings suggest that PBHs produced during magnetohydrodynamic turbulence in the very early universe may comprise a dominant part of dark matter.展开更多
Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the b...Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the behavior of legacy PFAS and emerging chlorinated polyfluoroalkyl ether sulfonic acids(Cl-PFESAs)in lettuce grown under environment-related exposure levels and assessed the human exposure risks from consuming contaminated lettuce.Overall,PFAS in lettuce were concentration-dependent,with long-chain PFAS tending to accumulate in roots and short-chain PFAS accumulating more in shoots.The enrichment of PFAS in lettuce was jointly influenced by their chain length and polar functional groups.Specifically,the root concentration factors(RCFs)of PFAS generally increased with increasing chain length,and RCF values of most perfluoroalkanesulfonic acids(PFSAs)were significantly higher than those of perfluoroalkyl carboxylic acids(PFCAs)with the same chain length(p<0.01),while the translocation factors(TFs)exhibited opposite trends.RCF values of perfluorooctane sulfonate(PFOS)and its alternatives,Cl-PFESAs,were ranked as follows:8:2 Cl-PFESA(mean:139)>6:2 Cl-PFESA(28.6)>PFOS(25.7),which was attributed to the increased molecular size and hydrophobicity resulting from the insertion of ether bonds and additional CF2 in 8:2 Cl-PFESA.Notably,TF value of 8:2 Cl-PFESA(mean:0.007)was the smallest among all PFAS,indicating 8:2 Cl-PFESA was difficult to transfer to nutritional compartments.Adults and children would exceed the most conservative health-based reference dose(RfD)by consuming approximately 15.9–148 g and 7.92–74.0 g of contaminated lettuce per day,implying high health risks.展开更多
Photoinitiators(PIs),as an important component of UV inks,are widely used in the printing of paper food packaging.Nevertheless,there is limited information concerning the identification of PIs in food packaging and th...Photoinitiators(PIs),as an important component of UV inks,are widely used in the printing of paper food packaging.Nevertheless,there is limited information concerning the identification of PIs in food packaging and their potential migration rules under natural storage condition.In this study,23 target PIs detected in paper food packaging were dominated by benzophenones(BZPs),followed by amine co-initiators(ACIs),thioxanthones(TXs)and phosphine oxides(POs).The concentration of ΣPIs ranged between 48.3 and 1.11×10^(5)ng/g.Meanwhile,the concentration ofΣPIs were found to be significantly higher in Corrugated paper compared to Polyethylene(PE)coated paper,Composite paper and White card paper.Benzophenone(BP)was found as the dominant PI congener in Corrugated paper,with the concentration ranging from 923-3.66×10^(4)ng/g.The migration quantity ofΣPIs increased in a time-dependent manner in the first 13 days and then eventually reached equilibrium.Low temperatures had a certain inhibitory effect on the migration of PIs from paper packaging to food.Under high exposure scenario,the EDIs of ΣPIs for children,adolescents,and adults were 31.4 ng/(kg bw·day),17.2 ng/(kg bw·day),and 14.4 ng/(kg bw·day),respectively,all of which did not exceed the reference dose,indicating that dietary intake of PIs does not pose any health risks to the human body.展开更多
A droplet generator is one of a key module for realizing the Sn-LPP EUV light source.One way of improving a conversion efficiency(CE)and relax tin contamination issue of Sn-LPP EUV light source is to produce tin dropl...A droplet generator is one of a key module for realizing the Sn-LPP EUV light source.One way of improving a conversion efficiency(CE)and relax tin contamination issue of Sn-LPP EUV light source is to produce tin droplet targets with suitable size.Less than several 10-μm nozzles are used to generate tin droplets.Particles from environment and chemical reaction compounds with high temperature tin cause nozzle clogging issue often.It is significant to develop a technical approach using a large diameter nozzle to produce mass-limited targets.Therefore,this paper demonstrated droplet ejection experiments based on electrohydrodynamics(EHD).Characteristics of isopropanol(IPA)droplet ejection by EHD droplet production platform that was designed and constructed in our laboratory.Characteristics of various process parameters on the IPA droplet production process were investigated.Images of droplet formation process were observed by using a droplet observation system and analyzed by image analysis software.Consequently,the smallest IPA droplet with a diameter of 13μm could be produced using a nozzle with a diameter of 50μm.Additionally,the EHD method could make droplets from 13μm to 55μm with applying voltage from 5.5 kV to 2.5 kV.In the future,EHD will apply to make mass-limited tin droplet targets under vacuum and high-temperature conditions,in order to increase the CE and to decrease tin debris.展开更多
Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over ...Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over the past decade,numerous reports have emerged on the presence of exogenous particles in human body,facilitated by the rapid development of separation and detection methods.The health risk associated with magnetic Fe_(x)O_(y) NP have garnered escalating attention due to their presence in human blood and brain tissues,especially for their potential association with neurodegenerative diseases like Alzheimer’s disease.In this paper,we provide a comprehensive overview of sources,analysis methods,environmental impacts,and health risks of magnetic Fe_(x)O_(y) NP.Currently,most researches are primarily based on engineered Fe_(x)O_(y) NP,while reports aboutmagnetic Fe_(x)O_(y) NP existing in real-world environments are still limited,especially for their occurrence levels in various environmental matrices,environmental transformation behavior,and biotoxic effects.Our study reviews this emerging pollutant,providing insights to address current research deficiencies and chart the course for future studies.展开更多
Fundamental physics often confronts complex symbolic problems with few guiding exemplars or established principles.While artificial intelligence(AI)offers promise,its typical need for vast datasets to learn from hinde...Fundamental physics often confronts complex symbolic problems with few guiding exemplars or established principles.While artificial intelligence(AI)offers promise,its typical need for vast datasets to learn from hinders its use in these information-scarce frontiers.We introduce learning at criticality(LaC),a reinforcement learning scheme that tunes large language models(LLMs)to a sharp learning transition,addressing this information scarcity.At this transition,LLMs achieve peak generalization from minimal data,exemplified by 7-digit base-7 addition-a test of nontrivial arithmetic reasoning.To elucidate this peak,we analyze a minimal concept-network model designed to capture the essence of how LLMs might link tokens.Trained on a single exemplar,this model also undergoes a sharp learning transition.This transition exhibits hallmarks of a second-order phase transition,notably power-law distributed solution path lengths.At this critical point,the system maximizes a“critical thinking pattern”crucial for generalization,enabled by the underlying scale-free exploration.This suggests LLMs reach peak performance by operating at criticality,where such explorative dynamics enable the extraction of underlying operational rules.We demonstrate LaC in quantum field theory:an 8B-parameter LLM,tuned to its critical point by LaC using a few exemplars of symbolic Matsubara sums,solves unseen,higher-order problems,significantly outperforming far larger models.LaC thus leverages critical phenomena,a physical principle,to empower AI for complex,data-sparse challenges in fundamental physics.展开更多
Implant-related infections and tissue inflammation are the main factors for peri-implantitis.Lack of antibacterial activity and poor soft tissue sealing property increase the occurrence probability of peri-implantitis...Implant-related infections and tissue inflammation are the main factors for peri-implantitis.Lack of antibacterial activity and poor soft tissue sealing property increase the occurrence probability of peri-implantitis.To prevent and treat peri-implantitis,cerium-doped defective titanium oxide coatings are prepared on medical titanium surfaces by plasma electrolytic oxidation and thermal reduction treatment.In the darkness,Ce-doped defective titanium oxide coatings with micro-porous structure surface can inhibit the bacteria adhesion to some extent with antibacterial rates of 38.0%against S.aureus and 65.0%against E.coli.Under near infrared(NIR)irradiation,Ce-doped defective titanium oxide coatings show good photothermal antibacterial activity with antibacterial rates of 99.9%against S.aureus and 99.9%against E.coli.Moreover,with the increasing content of Ce-doping,the coatings exhibit higher capacity to scavenge hydrogen peroxide(H2O2)and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)radical cation(ABTS^(·+)).The coatings with enhanced antioxidant effect can protect human gingival fibroblasts from oxidative stress damage by eliminating reactive oxygen species and promoting initial cell adhesion.Besides,Ce-doped coatings can regulate the immune microenvironment by up-regulating the expression of anti-inflammatory genes and down-regulating the pro-inflammatory genes.In vivo animal experiments further confirm the good antibacterial activity of Ce-doped defective titanium oxide coatings under NIR irradiation and good biosafety.This work provides a novel surface modification strategy for implant abutment,which shows good application prospects for preventing and treating peri-implantitis.展开更多
Quantum error correction is essential for realizing fault-tolerant quantum computing,where both the efficiency and accuracy of the decoding algorithms play critical roles.In this work,we introduce the implementation o...Quantum error correction is essential for realizing fault-tolerant quantum computing,where both the efficiency and accuracy of the decoding algorithms play critical roles.In this work,we introduce the implementation of the PLANAR algorithm,a software framework designed for fast and exact decoding of quantum codes with a planar structure.The algorithm first converts the optimal decoding of quantum codes into a partition function computation problem of an Ising spin glass model.Then it utilizes the exact Kac–Ward formula to solve it.In this way,PLANAR offers the exact maximum likelihood decoding in polynomial complexity for quantum codes with a planar structure,including the surface code with independent code-capacity noise and the quantum repetition code with circuit-level noise.Unlike traditional minimumweight decoders such as minimum-weight perfect matching(MWPM),PLANAR achieves theoretically optimal performance while maintaining polynomial-time efficiency.In addition,to demonstrate its capabilities,we exemplify the implementation using the rotated surface code,a commonly used quantum error correction code with a planar structure,and show that PLANAR achieves a threshold of approximately p_(uc)≈0.109 under the depolarizing error model,with a time complexity scaling of O(N^(0.69)),where N is the number of spins in the Ising model.展开更多
The evaluation of toxicity related to polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)and dioxin-like polychlorinated biphenyls(DL-PCBs)is crucial for a comprehensive risk assessment in real-world exposure scenar...The evaluation of toxicity related to polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)and dioxin-like polychlorinated biphenyls(DL-PCBs)is crucial for a comprehensive risk assessment in real-world exposure scenarios.This study employed a controlled feeding experiment to investigate the metabolic effects of dioxin-like compounds(DLCs)on laying hens via feed exposure.Diets enriched with two concentrations(1.17 and 5.13 pg toxic equivalents(TEQ)/g dry weight(dw))were administered over 14 days,followed by 28 days of clean feed.Metabolomics analyses of blood samples revealed significant metabolic variations between PCDD/Fs and DL-PCBs exposed groups and controls,reflecting the induced metabolic disruption.Distinct changes were observed in sphingosine,palmitoleic acid,linoleate,linolenic acid,taurocholic acid,indole acrylic acid,and dibutyl phthalate levels,implying possible connections between PCDD/Fs and DL-PCBs toxic effects and energy-neuronal imbalances,along with lipid accumulation and anomalous amino acid metabolism,impacting taurine metabolism.Moreover,we identified three differential endogenous metabolites—L-tryptophan,indole-3-acetaldehyde,and indole acrylic acid—as potential ligands for the aryl hydrocarbon receptor(AhR),suggesting their role inmediating PCDD/Fs and DL-PCBs toxicity.This comprehensive investigation provides novel insights into the metabolic alterations induced by PCDD/Fs and DL-PCBs in laying hens,thereby enhancing our ability to assess risks associated with their exposure in human populations.展开更多
Computing free energy is a fundamental problem in statistical physics.Recently,two distinct methods have been developed and have demonstrated remarkable success:the tensor-network-based contraction method and the neur...Computing free energy is a fundamental problem in statistical physics.Recently,two distinct methods have been developed and have demonstrated remarkable success:the tensor-network-based contraction method and the neural-network-based variational method.Tensor networks are accurate,but their application is often limited to low-dimensional systems due to the high computational complexity in high-dimensional systems.The neural network method applies to systems with general topology.However,as a variational method,it is not as accurate as tensor networks.In this work,we propose an integrated approach,tensor-network-based variational autoregressive networks(TNVAN),that leverages the strengths of both tensor networks and neural networks:combining the variational autoregressive neural network’s ability to compute an upper bound on free energy and perform unbiased sampling from the variational distribution with the tensor network’s power to accurately compute the partition function for small sub-systems,resulting in a robust method for precisely estimating free energy.To evaluate the proposed approach,we conducted numerical experiments on spin glass systems with various topologies,including two-dimensional lattices,fully connected graphs,and random graphs.Our numerical results demonstrate the superior accuracy of our method compared to existing approaches.In particular,it effectively handles systems with longrange interactions and leverages GPU efficiency without requiring singular value decomposition,indicating great potential in tackling statistical mechanics problems and simulating high-dimensional complex systems through both tensor networks and neural networks.展开更多
Extreme-mass-ratio inspiral(EMRI)signals pose significant challenges to gravitational wave(GW)data analysis,mainly owing to their highly complex waveforms and high-dimensional parameter space.Given their extended time...Extreme-mass-ratio inspiral(EMRI)signals pose significant challenges to gravitational wave(GW)data analysis,mainly owing to their highly complex waveforms and high-dimensional parameter space.Given their extended timescales of months to years and low signal-to-noise ratios,detecting and analyzing EMRIs with confidence generally relies on long-term observations.Besides the length of data,parameter estimation is particularly challenging due to non-local parameter degeneracies,arising from multiple local maxima,as well as flat regions and ridges inherent in the likelihood function.These factors lead to exceptionally high time complexity for parameter analysis based on traditional matched filtering and random sampling methods.To address these challenges,the present study explores a machine learning approach to Bayesian posterior estimation of EMRI signals,leveraging the recently developed flow matching technique based on ordinary differential equation neural networks.To our knowledge,this is also the first instance of applying continuous normalizing flows to EMRI analysis.Our approach demonstrates an increase in computational efficiency by several orders of magnitude compared to the traditional Markov chain Monte Carlo(MCMC)methods,while preserving the unbiasedness of results.However,we note that the posterior distributions generated by FMPE may exhibit broader uncertainty ranges than those obtained through full Bayesian sampling,requiring subsequent refinement via methods such as MCMC.Notably,when searching from large priors,our model rapidly approaches the true values while MCMC struggles to converge to the global maximum.Our findings highlight that machine learning has the potential to efficiently handle the vast EMRI parameter space of up to seventeen dimensions,offering new perspectives for advancing space-based GW detection and GW astronomy.展开更多
Pullorum disease and fowl typhoid are caused by the Salmonella serovars Gallinarum biovars Pullorum and Gal-linarum,respectively.The prevalence of these diseases varies across regions and is affected by different risk...Pullorum disease and fowl typhoid are caused by the Salmonella serovars Gallinarum biovars Pullorum and Gal-linarum,respectively.The prevalence of these diseases varies across regions and is affected by different risk fac-tors that remain insufficiently documented.To fill this knowledge gap,we have compiled a global dataset for its prevalence,drawing upon a collection of literature from the last seven decades obtained from bilingual databases.However,a more interactive and dynamic platform is still needed for both academics and policymakers to improve biosecurity measures,limit disease transmission,and prevent future outbreaks at the global and local levels.Here,we developed an advanced visualization platform to depict the prevalence of Salmonella Pullorum and Gallinarum,espe-cially in China,which is categorized by geographical region and temporal span.The platform offers a user-friendly,efficient,and visually engaging tool to explore the prevalence of pullorum disease and fowl typhoid between 1945 and 2021 in different regions.Additionally,this platform allows users to understand the influence of various fac-tors,such as breed,farm mode,economic usage and even the sex of the primary host,chickens,on the prevalence of this disease.We further provided a detailed overview of individual province within China.In particular,by selecting two different provinces on the interface,users can quickly visualize and grasp the disparities in disease prevalence between the chosen regions.This interactive toolkit enables a dynamic exploration of the patterns and factors con-tributing to the prevalence of Salmonella Pullorum and Gallinarum.This interactive platform is freely available open source at http://139.9.85.208/.展开更多
文摘Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.
基金Supported by the National key research and development program in the 14th five year plan 2021YFA1200700)the National Natural Science Foundation of China(62535018,62431025,62561160113)the Natural Science Foundation of Shanghai(23ZR1473400).
文摘Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon-based readout circuits in a single step.Based on this,we propose a photodiode based on an n-i-p structure,which removes the buffer layer and further simplifies the manufacturing process of quantum dot image sensors,thus reducing manufacturing costs.Additionally,for the noise complexity in quantum dot image sensors when capturing images,traditional denoising and non-uniformity methods often do not achieve optimal denoising re⁃sults.For the noise and stripe-type non-uniformity commonly encountered in infrared quantum dot detector imag⁃es,a network architecture has been developed that incorporates multiple key modules.This network combines channel attention and spatial attention mechanisms,dynamically adjusting the importance of feature maps to en⁃hance the ability to distinguish between noise and details.Meanwhile,the residual dense feature fusion module further improves the network's ability to process complex image structures through hierarchical feature extraction and fusion.Furthermore,the pyramid pooling module effectively captures information at different scales,improv⁃ing the network's multi-scale feature representation ability.Through the collaborative effect of these modules,the network can better handle various mixed noise and image non-uniformity issues.Experimental results show that it outperforms the traditional U-Net network in denoising and image correction tasks.
基金supported by the National Key Research and Development Program of China(No.2023YFC3707004)the National Natural Science Foundation of China(Nos.22376204,22076201 and 92143201)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB0750400,XDB0750100 and XDB0750000)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2019 QZKK0605).
文摘Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we found the boosting effects of halogens on organic pollutants formation during thermal processes.In situ electron paramagnetic resonance spectroscopy was used to distinguish the organic free radical intermediates of organic pollutants during thermal processes.The pure chlorine-containing reaction system dominantly induce the formation of highly chlorinated phenoxy radicals,whereas the pure bromine-containing reaction system induce the formation of semiquinone radicals.The results provide clear evidence for the molecular mechanisms by which halogen coexistence boosts pollutants formation.Coexisting halogens made the reactions much more complex.Bromine atom radicals(Br·)can enhance the level of active chlorine atoms radicals(Cl·),then(1)facilitating highly chlorinated organic radicals and toxic pollutants formation,(2)activating polycyclic aromatic hydrocarbons molecules for subsequent ring growth and(3)accelerating oxidation reactions.Combining the identification of organic free radical intermediates and characteristics of products,detailed mechanisms of halogens on the formations of organic pollutants during thermal-related processes were clarified,which can be helpful for their efficient control in the widespread bromines and chlorines co-existence reaction system.
基金supported by the National Natural Science Foundation of China(Nos.21976206,22136001,22276197,92143201)the National Key Research and Development Program of China(No.2020YFA0907500)the Beijing Natural Science Foundation(No.JQ22027)。
文摘Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy(WtE)incineration processes.This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals(EPFRs)from phenolic compounds based on the first-principles calculations.Two oxygen-deficient conditions were considered:oxygen vacancies at the top surface and on the subsurface.Our simulations indicate that the adsorption strength of phenol on theα-Fe_(2)O_(3)(0001)surface is enhanced by the presence of oxygen vacancies.However,the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule,particularly for the surface with a defective point at the top layer.Thermo-kinetic parameters were established over a temperature range of300-1000 K,and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface.The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeⅢto FeⅡ,which lower the oxidizing ability of surface reaction sites.The findings of this study provide us a promising approach to regulate the formation of EPFRs.
基金supported by Key Laboratory Funds for the Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics(Nos.HTKJ2022KL510003 and 6142207210303)Independent project of Hangzhou Institute for Advanced Study(No.2022ZZ01009)Science and Technology Project Affiliated to the Education Department of Chongqing Municipality(No.KJZD-K202101506)。
文摘In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to analyze the five failure factors that lead to the failure of the accelerator grid of a 30 cm diameter ion thruster under the working mode of 5 k W.Meanwhile,the acceleration stress levels corresponding to different failure factors are obtained.The results show that background pressure has the highest stress level on the grid's erosion.The accelerator grid aperture's mass sputtering rate under the rated vacuum degree(1×10^(-4)Pa)of 5 k W work mode is 8.78 times that of the baseline vacuum degree(1×10^(-6)Pa),and the mass sputtering rate under worse vacuum degree(5×10^(-3)Pa)is 5.08 times that of 1×10^(-4)Pa.Under the influence of the other four failure factors,namely,the voltage of the accelerator grid,upstream plasma density,the screen grid voltage and mass utilization efficiency,the mass sputtering rates of the accelerator grid hole are 2.32,2.67,1.98 and 2.51 times those of the accelerator grid hole under baseline condition,respectively.The ion sputtering results of two 30 cm diameter ion thrusters(both installed with new grids assembly)after working for 1000 h show that the mass sputtering rate of the accelerator grid hole under vacuum conditions of 5×10^(-3)Pa is 4.54 times that under the condition of 1×10^(-4)Pa,and the comparison error between simulation results and test results of acceleration stress is about 10%.In the subsequent ion thruster lifetime verification,the working vacuum degree can be adjusted according to the acceleration stress level of background pressure,so as to shorten the test time and reduce the test cost.
基金Supported by the Short-wave Infrared Camera Systems(B025F40622024)。
文摘The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.
基金Supported by the National Key Research and Development Program(2023YFC3107602)。
文摘Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes.For large-inertia scanning systems,constant-speed scanning requires substantial time to complete the reversal motion,reducing the system's adaptability to high-speed reversal scanning and decreasing scanning efficiency.This study proposes a novel sinusoidal variable-speed roll scanning strategy,which reduces abrupt changes in speed and acceleration,minimizing time loss during reversals.Based on the forward image motion compensation strategy in the pitch direction,we establish a line-of-sight(LOS)position calculation model with vertical flight path correction(VFPC),ensuring that the central LOS of the scanned image remains stable on the same horizontal line,facilitating accurate image stitching in whisk-broom imaging.Through theoretical analysis and simulation experiments,the proposed method improves the scanning efficiency by approximately 18.6%at a 90o whiskbroom imaging angle under the same speed height ratio conditions.The new VFPC method enables wide-field,high-resolution imaging,achieving single-line LOS horizontal stability with an accuracy of better than O.4 mrad.The research is of great significance to promote the further development of airborne area-array whisk-broom imaging technology toward wider fields of view,higher speed height ratios,and greater scanning efficiency.
基金supported by the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00570)Special Funding of China Postdoctoral Science Foundation(No.2023T160268)+3 种基金China Postdoctoral Science Foundation(No.2023M741362)the National natural science foundation of China(Nos.22276209 and 21822608)Research Center for Eco-Environmental Science(No.RCEES-TDZ-2021-7)the support from the Youth Innovation Promotion Association of CAS(No.Y2021019)。
文摘Electrocatalytic water splitting for hydrogen production is a key approach to tackling the current energy crisis.Among the catalysts,the traditional Pd@C catalysts are remarkable for their efficiency in hydrogen evolution.However,the high cost and scarcity of Pd catalysts,as well as the instability caused by the corrosiveness of carbon-based substrates,hinder their large-scale application.To overcome this challenge,an effective strategy is to construct highly dispersed Pd single atoms to improve palladium utilization and choose more stable materials as supports.In this study,TiO_(2-x)carriers with abundant oxygen vacancies were prepared and loaded with Pd by photoreduction deposition.Adjusting the palladium content resulted in three forms of Pd-loaded TiO_(2-x):nanoparticles(Pd@TiO_(2-x)(6%,10%)),nanoclusters(Pd@TiO_(2-x)(3%))and single atoms(Pd@TiO_(2-x)(1.5%)).The oxygen vacancies improved the stability of the titanium dioxide materials by providing more active hydrogen adsorption sites and increasing the affinity of Pd for active hydrogen.Single atom loading increased the frequency of oxygen holes in the support and the high activity of monatomic Pd promoted the adsorption of active hydrogen and facilitated the formation of active hydrogen intermediates.The synergistic effect of single atoms and oxygen vacancies improved the stability and catalytic activity of the composite material.Pd@TiO_(2-x)(1.5%)showed outstanding performance in hydrogen evolution in an acidic medium with an overpotential of only 24 m V at a current density of 10 m A/cm^(2)and a low Tafel rise of 41.9 m V/dec.This study provides an effective strategy for the development of high-performance hydrogen evolution(HER)catalysts.
基金supported by the International Partnership Program of the Chinese Academy of Sciences (Grant No.025GJHZ2023106GC)。
文摘Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of turbulences in the very early universe in sustaining intense and persistent fluctuations in energy or mass density,which could provide a natural mechanism for PBH formation in the primordial universe. We analyze the mass range and abundance of PBHs produced in the magnetohydrodynamic turbulence induced by the electroweak phase transition. Remarkably, we find that the mass range of the produced PBHs falls within the most viable“asteroid mass” window from the present-day observations, and within natural parameter regions their abundance can be sufficiently large. These findings suggest that PBHs produced during magnetohydrodynamic turbulence in the very early universe may comprise a dominant part of dark matter.
基金supported by the Fundamental Research Funds for Central Non-profit Scientific Institution(No.1610132022015)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750200)the National Natural Science Foundation of China(No.22176198).
文摘Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the behavior of legacy PFAS and emerging chlorinated polyfluoroalkyl ether sulfonic acids(Cl-PFESAs)in lettuce grown under environment-related exposure levels and assessed the human exposure risks from consuming contaminated lettuce.Overall,PFAS in lettuce were concentration-dependent,with long-chain PFAS tending to accumulate in roots and short-chain PFAS accumulating more in shoots.The enrichment of PFAS in lettuce was jointly influenced by their chain length and polar functional groups.Specifically,the root concentration factors(RCFs)of PFAS generally increased with increasing chain length,and RCF values of most perfluoroalkanesulfonic acids(PFSAs)were significantly higher than those of perfluoroalkyl carboxylic acids(PFCAs)with the same chain length(p<0.01),while the translocation factors(TFs)exhibited opposite trends.RCF values of perfluorooctane sulfonate(PFOS)and its alternatives,Cl-PFESAs,were ranked as follows:8:2 Cl-PFESA(mean:139)>6:2 Cl-PFESA(28.6)>PFOS(25.7),which was attributed to the increased molecular size and hydrophobicity resulting from the insertion of ether bonds and additional CF2 in 8:2 Cl-PFESA.Notably,TF value of 8:2 Cl-PFESA(mean:0.007)was the smallest among all PFAS,indicating 8:2 Cl-PFESA was difficult to transfer to nutritional compartments.Adults and children would exceed the most conservative health-based reference dose(RfD)by consuming approximately 15.9–148 g and 7.92–74.0 g of contaminated lettuce per day,implying high health risks.
基金supported by the National Natural Science Foundation of China(Nos.22106169,22136006,and 22021003)。
文摘Photoinitiators(PIs),as an important component of UV inks,are widely used in the printing of paper food packaging.Nevertheless,there is limited information concerning the identification of PIs in food packaging and their potential migration rules under natural storage condition.In this study,23 target PIs detected in paper food packaging were dominated by benzophenones(BZPs),followed by amine co-initiators(ACIs),thioxanthones(TXs)and phosphine oxides(POs).The concentration of ΣPIs ranged between 48.3 and 1.11×10^(5)ng/g.Meanwhile,the concentration ofΣPIs were found to be significantly higher in Corrugated paper compared to Polyethylene(PE)coated paper,Composite paper and White card paper.Benzophenone(BP)was found as the dominant PI congener in Corrugated paper,with the concentration ranging from 923-3.66×10^(4)ng/g.The migration quantity ofΣPIs increased in a time-dependent manner in the first 13 days and then eventually reached equilibrium.Low temperatures had a certain inhibitory effect on the migration of PIs from paper packaging to food.Under high exposure scenario,the EDIs of ΣPIs for children,adolescents,and adults were 31.4 ng/(kg bw·day),17.2 ng/(kg bw·day),and 14.4 ng/(kg bw·day),respectively,all of which did not exceed the reference dose,indicating that dietary intake of PIs does not pose any health risks to the human body.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA 0380000 and 0380300).
文摘A droplet generator is one of a key module for realizing the Sn-LPP EUV light source.One way of improving a conversion efficiency(CE)and relax tin contamination issue of Sn-LPP EUV light source is to produce tin droplet targets with suitable size.Less than several 10-μm nozzles are used to generate tin droplets.Particles from environment and chemical reaction compounds with high temperature tin cause nozzle clogging issue often.It is significant to develop a technical approach using a large diameter nozzle to produce mass-limited targets.Therefore,this paper demonstrated droplet ejection experiments based on electrohydrodynamics(EHD).Characteristics of isopropanol(IPA)droplet ejection by EHD droplet production platform that was designed and constructed in our laboratory.Characteristics of various process parameters on the IPA droplet production process were investigated.Images of droplet formation process were observed by using a droplet observation system and analyzed by image analysis software.Consequently,the smallest IPA droplet with a diameter of 13μm could be produced using a nozzle with a diameter of 50μm.Additionally,the EHD method could make droplets from 13μm to 55μm with applying voltage from 5.5 kV to 2.5 kV.In the future,EHD will apply to make mass-limited tin droplet targets under vacuum and high-temperature conditions,in order to increase the CE and to decrease tin debris.
基金supported by the National Key R&D Program of China(No.2023YFC3708302)the National Natural Science Foundation of China(Nos.22188102 and 22306041)+1 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research(No.YSBR-086)China Postdoctoral Science Foundation(No.2023M733679).
文摘Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over the past decade,numerous reports have emerged on the presence of exogenous particles in human body,facilitated by the rapid development of separation and detection methods.The health risk associated with magnetic Fe_(x)O_(y) NP have garnered escalating attention due to their presence in human blood and brain tissues,especially for their potential association with neurodegenerative diseases like Alzheimer’s disease.In this paper,we provide a comprehensive overview of sources,analysis methods,environmental impacts,and health risks of magnetic Fe_(x)O_(y) NP.Currently,most researches are primarily based on engineered Fe_(x)O_(y) NP,while reports aboutmagnetic Fe_(x)O_(y) NP existing in real-world environments are still limited,especially for their occurrence levels in various environmental matrices,environmental transformation behavior,and biotoxic effects.Our study reviews this emerging pollutant,providing insights to address current research deficiencies and chart the course for future studies.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFA1408604 for K.C.and X.C.)the National Natural Science Foundation of China(Grant Nos.12047503,12447103 for K.C.and X.C.,12325501 for P.Z.,and 12275263 for Y.D.and S.H.)+1 种基金the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301900 for Y.D.and S.H.)the Natural Science Foundation of Fujian Province of China(Grant No.2023J02032 for Y.D.and S.H.)。
文摘Fundamental physics often confronts complex symbolic problems with few guiding exemplars or established principles.While artificial intelligence(AI)offers promise,its typical need for vast datasets to learn from hinders its use in these information-scarce frontiers.We introduce learning at criticality(LaC),a reinforcement learning scheme that tunes large language models(LLMs)to a sharp learning transition,addressing this information scarcity.At this transition,LLMs achieve peak generalization from minimal data,exemplified by 7-digit base-7 addition-a test of nontrivial arithmetic reasoning.To elucidate this peak,we analyze a minimal concept-network model designed to capture the essence of how LLMs might link tokens.Trained on a single exemplar,this model also undergoes a sharp learning transition.This transition exhibits hallmarks of a second-order phase transition,notably power-law distributed solution path lengths.At this critical point,the system maximizes a“critical thinking pattern”crucial for generalization,enabled by the underlying scale-free exploration.This suggests LLMs reach peak performance by operating at criticality,where such explorative dynamics enable the extraction of underlying operational rules.We demonstrate LaC in quantum field theory:an 8B-parameter LLM,tuned to its critical point by LaC using a few exemplars of symbolic Matsubara sums,solves unseen,higher-order problems,significantly outperforming far larger models.LaC thus leverages critical phenomena,a physical principle,to empower AI for complex,data-sparse challenges in fundamental physics.
基金supported by the National Natural Science Foundation of China(No.52272283)the Science and Technology Commission of Shanghai Municipality(Nos.22S31902900 and 22ZR1457600)+3 种基金Youth Innovation Promotion Association CAS(No.2023263)Young Elite Scientists Sponsorship Program by CAST(No.2022-2024QNRC001)General Research Fund of the Research Grants Council(No.17207719)the Health and Medical Research Fund(No.20190244).
文摘Implant-related infections and tissue inflammation are the main factors for peri-implantitis.Lack of antibacterial activity and poor soft tissue sealing property increase the occurrence probability of peri-implantitis.To prevent and treat peri-implantitis,cerium-doped defective titanium oxide coatings are prepared on medical titanium surfaces by plasma electrolytic oxidation and thermal reduction treatment.In the darkness,Ce-doped defective titanium oxide coatings with micro-porous structure surface can inhibit the bacteria adhesion to some extent with antibacterial rates of 38.0%against S.aureus and 65.0%against E.coli.Under near infrared(NIR)irradiation,Ce-doped defective titanium oxide coatings show good photothermal antibacterial activity with antibacterial rates of 99.9%against S.aureus and 99.9%against E.coli.Moreover,with the increasing content of Ce-doping,the coatings exhibit higher capacity to scavenge hydrogen peroxide(H2O2)and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)radical cation(ABTS^(·+)).The coatings with enhanced antioxidant effect can protect human gingival fibroblasts from oxidative stress damage by eliminating reactive oxygen species and promoting initial cell adhesion.Besides,Ce-doped coatings can regulate the immune microenvironment by up-regulating the expression of anti-inflammatory genes and down-regulating the pro-inflammatory genes.In vivo animal experiments further confirm the good antibacterial activity of Ce-doped defective titanium oxide coatings under NIR irradiation and good biosafety.This work provides a novel surface modification strategy for implant abutment,which shows good application prospects for preventing and treating peri-implantitis.
基金supported by the National Natural Science Foundation of China(Grant Nos.12325501,12047503,and 12247104)the Chinese Academy of Sciences(Grant No.ZDRW-XX-2022-3-02)P.Z.is partially supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301900).
文摘Quantum error correction is essential for realizing fault-tolerant quantum computing,where both the efficiency and accuracy of the decoding algorithms play critical roles.In this work,we introduce the implementation of the PLANAR algorithm,a software framework designed for fast and exact decoding of quantum codes with a planar structure.The algorithm first converts the optimal decoding of quantum codes into a partition function computation problem of an Ising spin glass model.Then it utilizes the exact Kac–Ward formula to solve it.In this way,PLANAR offers the exact maximum likelihood decoding in polynomial complexity for quantum codes with a planar structure,including the surface code with independent code-capacity noise and the quantum repetition code with circuit-level noise.Unlike traditional minimumweight decoders such as minimum-weight perfect matching(MWPM),PLANAR achieves theoretically optimal performance while maintaining polynomial-time efficiency.In addition,to demonstrate its capabilities,we exemplify the implementation using the rotated surface code,a commonly used quantum error correction code with a planar structure,and show that PLANAR achieves a threshold of approximately p_(uc)≈0.109 under the depolarizing error model,with a time complexity scaling of O(N^(0.69)),where N is the number of spins in the Ising model.
基金supported by the National Key Research and Development Program of China (Nos.2018YFA0901101,2018YFA0901103,and 2017YFC1600301)the National Natural Science Foundation of China (Nos.22076216,21976201,and 21836004).
文摘The evaluation of toxicity related to polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)and dioxin-like polychlorinated biphenyls(DL-PCBs)is crucial for a comprehensive risk assessment in real-world exposure scenarios.This study employed a controlled feeding experiment to investigate the metabolic effects of dioxin-like compounds(DLCs)on laying hens via feed exposure.Diets enriched with two concentrations(1.17 and 5.13 pg toxic equivalents(TEQ)/g dry weight(dw))were administered over 14 days,followed by 28 days of clean feed.Metabolomics analyses of blood samples revealed significant metabolic variations between PCDD/Fs and DL-PCBs exposed groups and controls,reflecting the induced metabolic disruption.Distinct changes were observed in sphingosine,palmitoleic acid,linoleate,linolenic acid,taurocholic acid,indole acrylic acid,and dibutyl phthalate levels,implying possible connections between PCDD/Fs and DL-PCBs toxic effects and energy-neuronal imbalances,along with lipid accumulation and anomalous amino acid metabolism,impacting taurine metabolism.Moreover,we identified three differential endogenous metabolites—L-tryptophan,indole-3-acetaldehyde,and indole acrylic acid—as potential ligands for the aryl hydrocarbon receptor(AhR),suggesting their role inmediating PCDD/Fs and DL-PCBs toxicity.This comprehensive investigation provides novel insights into the metabolic alterations induced by PCDD/Fs and DL-PCBs in laying hens,thereby enhancing our ability to assess risks associated with their exposure in human populations.
基金supported by Projects 12325501,12047503,and 12247104 of the National Natural Science Foundation of ChinaProject ZDRW-XX-2022-3-02 of the Chinese Academy of Sciencessupported by the Innovation Program for Quantum Science and Technology project 2021ZD0301900。
文摘Computing free energy is a fundamental problem in statistical physics.Recently,two distinct methods have been developed and have demonstrated remarkable success:the tensor-network-based contraction method and the neural-network-based variational method.Tensor networks are accurate,but their application is often limited to low-dimensional systems due to the high computational complexity in high-dimensional systems.The neural network method applies to systems with general topology.However,as a variational method,it is not as accurate as tensor networks.In this work,we propose an integrated approach,tensor-network-based variational autoregressive networks(TNVAN),that leverages the strengths of both tensor networks and neural networks:combining the variational autoregressive neural network’s ability to compute an upper bound on free energy and perform unbiased sampling from the variational distribution with the tensor network’s power to accurately compute the partition function for small sub-systems,resulting in a robust method for precisely estimating free energy.To evaluate the proposed approach,we conducted numerical experiments on spin glass systems with various topologies,including two-dimensional lattices,fully connected graphs,and random graphs.Our numerical results demonstrate the superior accuracy of our method compared to existing approaches.In particular,it effectively handles systems with longrange interactions and leverages GPU efficiency without requiring singular value decomposition,indicating great potential in tackling statistical mechanics problems and simulating high-dimensional complex systems through both tensor networks and neural networks.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFC2201901,2021YFC2203004,2020YFC2200100 and 2021YFC2201903)International Partnership Program of the Chinese Academy of Sciences(Grant No.025GJHZ2023106GC)+4 种基金the financial support from Brazilian agencies Funda??o de AmparoàPesquisa do Estado de S?o Paulo(FAPESP)Funda??o de Amparoà Pesquisa do Estado do Rio Grande do Sul(FAPERGS)Fundacao de Amparoà Pesquisa do Estado do Rio de Janeiro(FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nível Superior(CAPES)。
文摘Extreme-mass-ratio inspiral(EMRI)signals pose significant challenges to gravitational wave(GW)data analysis,mainly owing to their highly complex waveforms and high-dimensional parameter space.Given their extended timescales of months to years and low signal-to-noise ratios,detecting and analyzing EMRIs with confidence generally relies on long-term observations.Besides the length of data,parameter estimation is particularly challenging due to non-local parameter degeneracies,arising from multiple local maxima,as well as flat regions and ridges inherent in the likelihood function.These factors lead to exceptionally high time complexity for parameter analysis based on traditional matched filtering and random sampling methods.To address these challenges,the present study explores a machine learning approach to Bayesian posterior estimation of EMRI signals,leveraging the recently developed flow matching technique based on ordinary differential equation neural networks.To our knowledge,this is also the first instance of applying continuous normalizing flows to EMRI analysis.Our approach demonstrates an increase in computational efficiency by several orders of magnitude compared to the traditional Markov chain Monte Carlo(MCMC)methods,while preserving the unbiasedness of results.However,we note that the posterior distributions generated by FMPE may exhibit broader uncertainty ranges than those obtained through full Bayesian sampling,requiring subsequent refinement via methods such as MCMC.Notably,when searching from large priors,our model rapidly approaches the true values while MCMC struggles to converge to the global maximum.Our findings highlight that machine learning has the potential to efficiently handle the vast EMRI parameter space of up to seventeen dimensions,offering new perspectives for advancing space-based GW detection and GW astronomy.
基金supported by the National Program on the Key Research Project of China(2022YFC2604201)the Zhejiang Provincial Natural Science Founda-tion of China(LZ24C180002+2 种基金LR19C180001)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0083)the Open Project Program of the Jiangsu Key Laboratory of Zoonosis(R1902).
文摘Pullorum disease and fowl typhoid are caused by the Salmonella serovars Gallinarum biovars Pullorum and Gal-linarum,respectively.The prevalence of these diseases varies across regions and is affected by different risk fac-tors that remain insufficiently documented.To fill this knowledge gap,we have compiled a global dataset for its prevalence,drawing upon a collection of literature from the last seven decades obtained from bilingual databases.However,a more interactive and dynamic platform is still needed for both academics and policymakers to improve biosecurity measures,limit disease transmission,and prevent future outbreaks at the global and local levels.Here,we developed an advanced visualization platform to depict the prevalence of Salmonella Pullorum and Gallinarum,espe-cially in China,which is categorized by geographical region and temporal span.The platform offers a user-friendly,efficient,and visually engaging tool to explore the prevalence of pullorum disease and fowl typhoid between 1945 and 2021 in different regions.Additionally,this platform allows users to understand the influence of various fac-tors,such as breed,farm mode,economic usage and even the sex of the primary host,chickens,on the prevalence of this disease.We further provided a detailed overview of individual province within China.In particular,by selecting two different provinces on the interface,users can quickly visualize and grasp the disparities in disease prevalence between the chosen regions.This interactive toolkit enables a dynamic exploration of the patterns and factors con-tributing to the prevalence of Salmonella Pullorum and Gallinarum.This interactive platform is freely available open source at http://139.9.85.208/.
