In this paper, we propose an optical quantization scheme for all-optical analog-to-digital conversion that facilitates photonics integration. A segment of 10-m photonic crystal fiber with a high nonlinear coefficient ...In this paper, we propose an optical quantization scheme for all-optical analog-to-digital conversion that facilitates photonics integration. A segment of 10-m photonic crystal fiber with a high nonlinear coefficient of 62.8 W-1/kin is utilized to realize large scale soliton self-frequency shift relevant to the power of the sampled optical signal. Furthermore, a 100-m dispersion-increasing fiber is used as the spectral compression module for further resolution enhancement. Simulation results show that 317-nm maximum wavelength shift is realized with 1550-nm initial wavelength and 6-bit quantization resolution is obtained with a subsequent spectral compression process.展开更多
In this paper, we optimize a proposed all-optical quantization scheme based on soliton self-frequency shift(SSFS)and pre-chirp spectral compression techniques. A 10m-long high-nonlinear photonic crystal fiber(PCF) is ...In this paper, we optimize a proposed all-optical quantization scheme based on soliton self-frequency shift(SSFS)and pre-chirp spectral compression techniques. A 10m-long high-nonlinear photonic crystal fiber(PCF) is used as an SSFS medium relevant to the power of the sampled optical pulses. Furthermore, a 10m-long dispersion flattened hybrid cladding hexagonal-octagonal PCF(6/8-PCF) is utilized as a spectral compression medium to further enhance the resolution. Simulation results show that 6-bit quantization resolution is still obtained when a 100m-long dispersion-increasing fiber(DIF)is replaced by a 6/8-PCF in spectral compression module.展开更多
Raman soliton self-frequency shifted to mid-infrared band（λ 〉 2 μm） has been achieved in an air-silica microstructure fiber（MF）. The MF used in our experiment has an elliptical core with diameters of 1.08 and 2...Raman soliton self-frequency shifted to mid-infrared band（λ 〉 2 μm） has been achieved in an air-silica microstructure fiber（MF）. The MF used in our experiment has an elliptical core with diameters of 1.08 and 2.48 μm for fast and slow axis. Numerical simulation shows that each fundamental orthogonal polarization mode has two wide-spaced λZDW and theλZDW pairs located at 701/2110 nm and 755/2498 nm along the fast and slow axis, respectively. Using 810-nm Ti：sapphire femtosecond laser as pump, when the output power varies from 0.3 to 0.5 W, the furthest red-shift Raman solitons in both fast and slow axis shift from near-infrared band to mid-infrared band, reaching as far as 2030 and 2261 nm. Also, midinfrared Raman solitons can always be generated for pump wavelength longer than 790 nm if output pump power reaches0.5 W. Specifically, with pump power at 0.5 W, the mid-infrared soliton in slow axis shifts from 2001 to 2261 nm when the pump changes from 790 nm to 810 nm. This means only a 20 nm change of pump results in 260 nm tunability of a mid-infrared soliton.展开更多
By adjusting the polarisation state of the pump at 805 nm parallel to slow （x） and fast （y） axes of the highly birefringent photonic crystal fibre with zero dispersion wavelengths 790 nm and 750 nm, this paper dem...By adjusting the polarisation state of the pump at 805 nm parallel to slow （x） and fast （y） axes of the highly birefringent photonic crystal fibre with zero dispersion wavelengths 790 nm and 750 nm, this paper demonstrates the efficient polarisation-sensitive four wave mixing involved in pump, anti-Stokes and Stokes signals and soliton self- frequency shift effects induced by the phase-matching between red-shifted solitons and blue-shifted dispersive waves. If the reduction of coupling efficiency to the circular pump laser mode or other circular fibres due to asymmetry of the core is neglected, more than 98% of the total input power is kept in a single linear polarisation. Controlled dispersion characteristic of the doublet of fundamental guided-modes results in achieving light field strongly confined in principal axes of photonic crystal fibre, and enhancing the corresponding nonlinear-optical process through the remarkable nonlinear birefringence.展开更多
This paper presents an efficient model reduction technique for linear time-varying systems based on shifted Legendre polynomials.The approach constructs approximate low-rank decomposition factors of finite-time Gramia...This paper presents an efficient model reduction technique for linear time-varying systems based on shifted Legendre polynomials.The approach constructs approximate low-rank decomposition factors of finite-time Gramians directly from the expansion coefficients of impulse responses.Leveraging these factors,we develop two model reduction algorithms that integrate the low-rank square root method with dominant subspace projection.Our method is computationally efficient and flexible,requiring only a few matrix-vector operations and a singular value decomposition of a low-dimensional matrix,thereby avoiding the need to solve differential Lyapunov equations.Numerical experiments confirm the effectiveness of the proposed approach.展开更多
With the evolution of next-generation network technologies,the complexity of network management has significantly increased,and the means of network attacks are diversified,bringing new challenges to network traffic c...With the evolution of next-generation network technologies,the complexity of network management has significantly increased,and the means of network attacks are diversified,bringing new challenges to network traffic classification.This paper presents a general AIdriven network traffic classification workflow and elaborates on a traffic data and feature engineering framework.Most importantly,it analyzes the concept and causes of data distribution shifts in ne twork traffic,proposing detection methods and countermeasures.Experimental results on real traffic collected at different time intervals show that application evolution can induce data distribution shifts,which in turn lead to a noticeable degradation in traffic classification performance.Comparative drift detection experiments further confirm that such shifts are more evident over long-term intervals,while short-term traffic remains relatively stable.These findings demonstrate the necessity of incorporating drift-aware mechanisms into AI-driven network traffic classification systems.展开更多
Northeast China(NEC),a critical agricultural and ecological zone,has experienced intensified hydrological variability under global warming,with cascading impacts on food security and ecosystem resilience.This study ut...Northeast China(NEC),a critical agricultural and ecological zone,has experienced intensified hydrological variability under global warming,with cascading impacts on food security and ecosystem resilience.This study utilized observational data and two new generation reanalysis products(i.e.,the fifth major global reanalysis produced by ECMWF(ERA5)and the Japanese Reanalysis for Three Quarters of a Century(JRA-3Q))to investigate the shift changes in precipitation in NEC around 2000 and associated water vapor transport.The analysis identified a pivotal interdecadal shift in 1998/99,transitioning from moderate increases(17.5 mm/10 yr during 1980-1998)to accelerated but more variable precipitation growth(85.4 mm/10 yr post-1999).While the mean precipitation during the post-shift period decreased,enhanced anticyclonic circulation amplified moisture divergence over continental NEC,redirecting vapor flux toward coastal regions.Crucially,trajectory analysis demonstrated regime-dependent moisture sourcing:midlatitude westerlies dominated during wet extremes(44% of trajectories in 1998),whereas East Asian monsoon flows prevailed in drought years(36% of trajectories in 2007).The post-1998 period exhibited increased reliance on localized recycling(45%of mid-tropospheric trajectories),reflecting weakened monsoonal inflow.These findings highlight NEC’s growing vulnerability to competing moisture pathways and atmospheric blocking-a dual mechanism that explains rising extremes despite declining mean precipitation.By reconciling dataset discrepancies(ERA5 vs.JRA-3Q trends)and elucidating circulation-precipitation linkages,this work provides actionable insights for climate-resilient agriculture in NEC’s water-stressed ecosystems.展开更多
Objective:To investigate the distribution of Traditional Chinese Medicine(TCM)constitution among night-shift nurses at a public tertiary-level Class A hospital,thereby identifying new approaches for developing effecti...Objective:To investigate the distribution of Traditional Chinese Medicine(TCM)constitution among night-shift nurses at a public tertiary-level Class A hospital,thereby identifying new approaches for developing effective interventions to enhance their health status.Methods:A total of 601 nurses employed at a public tertiary-level Class A hospital from August 2024 to August 2025 participated in the survey.Analysis was conducted using the Traditional Chinese Medicine Constitution Questionnaire.Results:The most prevalent TCM constitution types among night-shift nurses were Yang Deficiency Constitution(50.4%),Yin Deficiency Constitution(49.8%),Qi Deficiency Constitution(45.4%),and Phlegm-Dampness Constitution(45.1%).Conclusion:A high proportion of clinical night-shift nursing staff exhibit imbalanced constitution types,severely impacting their physical and mental health.Nursing administrators should implement targeted TCM constitution-based health maintenance and regulation to improve the health status of nursing personnel.展开更多
As global climate change intensifies,alpine plants are facing dual pressures of habitat loss and rapid environmental degradation.As one of the world's most biodiverse countries,China's potential shifts in alpi...As global climate change intensifies,alpine plants are facing dual pressures of habitat loss and rapid environmental degradation.As one of the world's most biodiverse countries,China's potential shifts in alpine plant distribution and their profound impact on fragile ecosystems have become a focus of ecological research and conservation efforts,with increasing urgency.Meconopsis,a typical representative of Chinese alpine plants,exhibits diverse adaptability,making it an ideal model for studying how alpine species respond to extreme environmental changes.A lack of comprehensive genus-level analyses may hinder the development of long-term conservation and management strategies.Given the genus's ecological importance,vulnerability,and the risk of trait homogenization in genus-level modeling,there is an urgent need to assess its future distribution patterns,migration trends,and adaptive mechanisms based on habitat classification.In this study,we employed the Maxent model,integrating multidimensional environmental variables,to develop genus-level models and representative habitat-based models(forest,meadows,and periglacial).Results indicate a northwestward expansion and southeastward contraction of suitable habitats under future climate scenarios,with migration patterns in latitude and elevation showing stage-specific characteristics.Key environmental factors varied across models but were mostly associated with seasonal growth traits and microhabitat conditions,highlighting both the universal ecological requirements and niche differentiation within Meconopsis.Based on these findings,we propose a dynamic conservation strategy framework informed by stage-specific responses and habitat differences.Future efforts should focus on incorporating alpine-specific environmental variables and optimizing specimen collection strategies to enhance model performance and support landscape planning and biodiversity conservation.展开更多
Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=...Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=Sr,Ba,Ca),we reveal that conventional thermal expansion theory cannot adequately explain these phenomena.Instead,our frozen phonon analysis identifies local electron-phonon coupling as the dominant mechanism,where anisotropic thermal vibrations selectively distort the asymmetric Eu-5d potential well that arises from the dopant’s coordination environment.This distortion manifests through the temperature-sensitiveΔ_(f−d) parameter governing the 5d→4f transition energy,directly controlling spectral shifts.Our findings establish a universal framework for HIEPS in rare-earth phosphors and enable a Δ_(f−d)-guided strategy for designing thermally stable phosphors.展开更多
Research on tourism climate comfort is undergoing a paradigm shift from classic static assessment to intelligent dynamic sensing.Early models(such as temperature-humidity index and tourism climate index)established ba...Research on tourism climate comfort is undergoing a paradigm shift from classic static assessment to intelligent dynamic sensing.Early models(such as temperature-humidity index and tourism climate index)established based on data of meteorological stations laid the foundation for the discipline but were unable to meet the dynamic demands of climate change,spatial heterogeneity,and individual experience.Global climate change is reshaping the landscape of tourism comfort and driving the assessment to shift towards future risk prediction.Downscaling technology becomes the key to connecting global scenarios and local assessments.Remote sensing and Internet of Things technologies have constructed a"sky-ground"collaborative sensing network,achieving a revolution in data acquisition.Artificial intelligence and big data analysis serve as the intelligent core to drive research from description to prediction.The new paradigm has significant potential in improving assessment accuracy and timeliness,but also faces challenges such as data integration,model interpretability,interdisciplinary integration,and ethical privacy.In the future,it is needed to develop interpretable AI,construct climate digital twins,and promote full-chain coupling research.This transformation is not merely an upgrade of methods,but a fundamental shift in the study of philosophy from an"environment-centered"perspective to an"experience-centered"one,providing key scientific support for sustainable tourism.展开更多
Sleep is a biological phenomenon with highly conserved evolutionary characteristics.The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults get at least 7 hours of sleep per night[1...Sleep is a biological phenomenon with highly conserved evolutionary characteristics.The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults get at least 7 hours of sleep per night[1].However,the stress caused by fast-paced life often leads to sleep deprivation(SD).SD is strongly associated with damage to the auditory system[2,3].Obstructive sleep apnea-hypopnea syndrome(OSAHS)is a common sleep disorder.Clinical observations indicate that some patients with OSAHS experience persistent hearing loss accompanied by tinnitus and other symptoms[4].More than 61.8%of patients with sudden deafness experienced SD[5].展开更多
Academic journals,consulting firms,and mainstream media have often published“predictions”about the future develop-ment of medical and health care.These publications often emphasize the potential of cutting-edge scie...Academic journals,consulting firms,and mainstream media have often published“predictions”about the future develop-ment of medical and health care.These publications often emphasize the potential of cutting-edge scientific or technical breakthroughs.Health Care Science looks at the problem from another perspective.We focus on how these changes enter the health system,how they operate in the real world,and how they reshape the organization and governance of medical services.At the beginning of 2026,we envision the following three major shifts that will reshape healthcare.展开更多
At the start of China’s 15th Five-Year Plan period(2026–2030),signals from March’s Two Sessions point to a subtle but notable change in direction.Policymakers are moving beyond an emphasis on headline growth figure...At the start of China’s 15th Five-Year Plan period(2026–2030),signals from March’s Two Sessions point to a subtle but notable change in direction.Policymakers are moving beyond an emphasis on headline growth figures and are instead concentrating on building a more resilient economic foundation in a volatile global environment.展开更多
Potassium(K)is known to enhance the catalytic performance of Fe-based catalysts in the reverse water-gas shift(rWGS)reaction,which is highly relevant during Fischer-Tropsch(FT)synthesis of CO_(2)-H_(2) mixtures.To elu...Potassium(K)is known to enhance the catalytic performance of Fe-based catalysts in the reverse water-gas shift(rWGS)reaction,which is highly relevant during Fischer-Tropsch(FT)synthesis of CO_(2)-H_(2) mixtures.To elucidate the mechanistic role of K promoter,we employed density functional theory(DFT)calculations in conjunction with microkinetic modelling for two representative surface terminations of Hägg carbide(χ-Fe_(5)C_(2)),i.e.,(010)and(510).K_(2)O results in stronger adsorption of CO_(2)and H_(2) on Hägg carbide and promotes C–O bond dissociation of adsorbed CO_(2)by increasing the electron density on Fe atoms close to the promoter oxide.The increased electron density of the surface Fe atoms results in an increased electron-electron repulsion with bonding orbitals of adsorbed CO_(2).Microkinetics simulations predict that K_(2)O increases the CO_(2)conversion during CO_(2)-FT synthesis.K_(2)O also enhances CO adsorption and dissociation,facilitating the formation of methane,used here as a proxy for hydrocarbons formation during CO_(2)-FT synthesis.CO dissociation and O removal via H_(2)O compete as the rate-controlling steps in CO_(2)-FT.展开更多
A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,...A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,6 receptors.This identifies their potential threat to public health.However,our understanding of the molecular basis for the switch of receptor preference is still limited.In this study,we employed the random forest algorithm to identify the potentially key amino acid sites within hemagglutinin(HA),which are associated with the receptor binding ability of H9N2 avian influenza virus(AIV).Subsequently,these sites were further verified by receptor binding assays.A total of 12 substitutions in the HA protein(N158D,N158S,A160 N,A160D,A160T,T163I,T163V,V190T,V190A,D193 N,D193G,and N231D)were predicted to prefer binding toα-2,6 receptors.Except for the V190T substitution,the other substitutions were demonstrated to display an affinity for preferential binding toα-2,6 receptors by receptor binding assays.Especially,the A160T substitution caused a significant upregulation of immune-response genes and an increased mortality rate in mice.Our findings provide novel insights into understanding the genetic basis of receptor preference of the H9N2 AIV.展开更多
The current dialogue system can be sensitive to the emotions in the user's words,generating an empathetic response to help calm the user's emotions.But in some cases,eliciting empathetic responses may not adeq...The current dialogue system can be sensitive to the emotions in the user's words,generating an empathetic response to help calm the user's emotions.But in some cases,eliciting empathetic responses may not adequately mitigate the adverse effects that the current conversation topic is having on users.The dialogue system will continue the conversation with the user under this uncomfortable topic,which will lead to a worse chat situation or even an impasse.To solve this problem,a dialogue system that can change the topic autonomously according to the user's emotions is proposed in this paper.Specifically,the dialogue system first collects the emotional semantic information of the users and then detects it according to the emotion classification module.Once the detection results show that the user is in a bad mood,the topic change module selects a new topic from the context to shift to and generates a response.This not only helps to calm the user's mood but also move the conversation to a new area,steering the user away from the uncomfortable topic.The experimental results show that the proposed method incurs less cost in terms of content quality,but improves the emotional perception ability.Additionally,it endows the dialogue system with the ability to change the topic,and improves the user's dialogue experience.展开更多
The transition energies of the 1s^(2)2s^(2)S_(1/2)→1s^(2)2p^(2)p_(1/2,3/2)transitions in Li-like Th87+ions were calculated by combining the multi-configuration Dirac-Hartree-Fock(MCDHF)method with the model-quantum e...The transition energies of the 1s^(2)2s^(2)S_(1/2)→1s^(2)2p^(2)p_(1/2,3/2)transitions in Li-like Th87+ions were calculated by combining the multi-configuration Dirac-Hartree-Fock(MCDHF)method with the model-quantum electrodynamics(modelQED)approach.The effects of electron correlation,Breit interaction,and QED effects were analyzed in detail.The isotope shifts,including the mass shifts and field shifts,due to the 2s2S_(1/2)→2p^(2)P_(1/2,3/2)transitions were then calculated using two different methods,namely,the MCDHF method and the finite-field method.The results show that these two methods are in excellent agreement.展开更多
With the continuous improvement of the medical industry’s requirements for the professional capabilities of nursing talents,traditional nursing teaching models can hardly meet the needs of complex nursing work in neu...With the continuous improvement of the medical industry’s requirements for the professional capabilities of nursing talents,traditional nursing teaching models can hardly meet the needs of complex nursing work in neurology.This paper focuses on nursing education for neurology nursing students and explores the construction of the“one-on-one”teaching model,aiming to achieve a paradigm shift in nursing education.By analyzing the current status of neurology nursing education,this paper identifies the problems in traditional teaching models.Combining the advantages of the“one-on-one”teaching model,it elaborates on the construction path of this model from aspects such as the selection and training of teaching instructors,the design of teaching content,the innovation of teaching methods,and the improvement of the teaching evaluation system.The research shows that the“one-on-one”teaching model can significantly enhance nursing students’mastery of professional knowledge,clinical operation skills,communication skills,and emergency response capabilities,as well as strengthen their professional identity and sense of responsibility.It provides an effective way to cultivate high-quality nursing talents who can meet the needs of neurology nursing work and promotes the innovative development of nursing education.展开更多
National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire prote...National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire protection technologies has opened avenues for China to access a wealth of documents and codes,which are crucial in crafting regulations and developing a robust,scientific framework for fire code formulation.However,the translation of these codes into Chinese has been inadequate,thereby diminishing the benefits of technological exchange and collaborative learning.This underscores the necessity for comprehensive research into code translation,striving for higher-quality translations guided by established translation theories.In this study,we translated the initial segment of the NFPA 1 Fire Code into Chinese and examined both the source text and target text through the lens of Translation Shift Theory,a concept introduced by Catford.The conclusion culminated in identifying four key shifts across various linguistic levels:lexis,sentences,and groups,to ensure an accurate and precise translation of fire codes.This study offers a through and lucid explanation of how the translator integrates Catford’s theories to solve technical challenges in NFPA 1 Fire Code translation,and establish essential standards for construction translation practices.展开更多
基金Project supported by the National Basic Research Program of China(Grant Nos.2010CB327605 and 2010CB328304)the National High-Technology Research and Development Program of China(Grant No.2013AA031501)+7 种基金the National Natural Science Foundation of China(Grant No.61307109)the Research Foundation from Ministry of Education of China(Grant No.109015)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NECT-11-0596)the Beijing Nova Program,China(Grant No.2011066)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120005120021)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant No.2013RC1202)the China Postdoctoral Science Foundation(Grant No.2012M511826)the Postdoctoral Science Foundation of Guangdong Province,China(Grant No.244331)
文摘In this paper, we propose an optical quantization scheme for all-optical analog-to-digital conversion that facilitates photonics integration. A segment of 10-m photonic crystal fiber with a high nonlinear coefficient of 62.8 W-1/kin is utilized to realize large scale soliton self-frequency shift relevant to the power of the sampled optical signal. Furthermore, a 100-m dispersion-increasing fiber is used as the spectral compression module for further resolution enhancement. Simulation results show that 317-nm maximum wavelength shift is realized with 1550-nm initial wavelength and 6-bit quantization resolution is obtained with a subsequent spectral compression process.
文摘In this paper, we optimize a proposed all-optical quantization scheme based on soliton self-frequency shift(SSFS)and pre-chirp spectral compression techniques. A 10m-long high-nonlinear photonic crystal fiber(PCF) is used as an SSFS medium relevant to the power of the sampled optical pulses. Furthermore, a 10m-long dispersion flattened hybrid cladding hexagonal-octagonal PCF(6/8-PCF) is utilized as a spectral compression medium to further enhance the resolution. Simulation results show that 6-bit quantization resolution is still obtained when a 100m-long dispersion-increasing fiber(DIF)is replaced by a 6/8-PCF in spectral compression module.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61405172,61405173,and 61275093)the Natural Science Foundation of Hebei Province,China(Grant No.F2014203194)+1 种基金the College Science Research Program of Hebei Province,China(Grant No.QN20131044)the Program of Independent Research for the Young Teachers of Yanshan University of China(Grant No.13LGB017)
文摘Raman soliton self-frequency shifted to mid-infrared band（λ 〉 2 μm） has been achieved in an air-silica microstructure fiber（MF）. The MF used in our experiment has an elliptical core with diameters of 1.08 and 2.48 μm for fast and slow axis. Numerical simulation shows that each fundamental orthogonal polarization mode has two wide-spaced λZDW and theλZDW pairs located at 701/2110 nm and 755/2498 nm along the fast and slow axis, respectively. Using 810-nm Ti：sapphire femtosecond laser as pump, when the output power varies from 0.3 to 0.5 W, the furthest red-shift Raman solitons in both fast and slow axis shift from near-infrared band to mid-infrared band, reaching as far as 2030 and 2261 nm. Also, midinfrared Raman solitons can always be generated for pump wavelength longer than 790 nm if output pump power reaches0.5 W. Specifically, with pump power at 0.5 W, the mid-infrared soliton in slow axis shifts from 2001 to 2261 nm when the pump changes from 790 nm to 810 nm. This means only a 20 nm change of pump results in 260 nm tunability of a mid-infrared soliton.
基金partly supported by the National Basic Research Program (Grant Nos. 2010CB327605 and 2010CB328300)Nationa lHigh-Technology Research and Development Program of China (Grant Nos. 2007AA03Z447 and 2009AA01Z220)+2 种基金the National Natural Science Foundation of China (Grant No. 60807022)the Key Grant of Ministry of Education of China (Grant No. 109015)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070013001)
文摘By adjusting the polarisation state of the pump at 805 nm parallel to slow （x） and fast （y） axes of the highly birefringent photonic crystal fibre with zero dispersion wavelengths 790 nm and 750 nm, this paper demonstrates the efficient polarisation-sensitive four wave mixing involved in pump, anti-Stokes and Stokes signals and soliton self- frequency shift effects induced by the phase-matching between red-shifted solitons and blue-shifted dispersive waves. If the reduction of coupling efficiency to the circular pump laser mode or other circular fibres due to asymmetry of the core is neglected, more than 98% of the total input power is kept in a single linear polarisation. Controlled dispersion characteristic of the doublet of fundamental guided-modes results in achieving light field strongly confined in principal axes of photonic crystal fibre, and enhancing the corresponding nonlinear-optical process through the remarkable nonlinear birefringence.
文摘This paper presents an efficient model reduction technique for linear time-varying systems based on shifted Legendre polynomials.The approach constructs approximate low-rank decomposition factors of finite-time Gramians directly from the expansion coefficients of impulse responses.Leveraging these factors,we develop two model reduction algorithms that integrate the low-rank square root method with dominant subspace projection.Our method is computationally efficient and flexible,requiring only a few matrix-vector operations and a singular value decomposition of a low-dimensional matrix,thereby avoiding the need to solve differential Lyapunov equations.Numerical experiments confirm the effectiveness of the proposed approach.
基金supported by ZTE Industry-University-Institute Cooperation Funds under Grant No.HC-CN-20220607009。
文摘With the evolution of next-generation network technologies,the complexity of network management has significantly increased,and the means of network attacks are diversified,bringing new challenges to network traffic classification.This paper presents a general AIdriven network traffic classification workflow and elaborates on a traffic data and feature engineering framework.Most importantly,it analyzes the concept and causes of data distribution shifts in ne twork traffic,proposing detection methods and countermeasures.Experimental results on real traffic collected at different time intervals show that application evolution can induce data distribution shifts,which in turn lead to a noticeable degradation in traffic classification performance.Comparative drift detection experiments further confirm that such shifts are more evident over long-term intervals,while short-term traffic remains relatively stable.These findings demonstrate the necessity of incorporating drift-aware mechanisms into AI-driven network traffic classification systems.
基金supported by the National Natural Science Foundation of China[grant numbers 42275185 and 42205032]the Fundamental Research Funds for the Central Universities[grant number B250201118]。
文摘Northeast China(NEC),a critical agricultural and ecological zone,has experienced intensified hydrological variability under global warming,with cascading impacts on food security and ecosystem resilience.This study utilized observational data and two new generation reanalysis products(i.e.,the fifth major global reanalysis produced by ECMWF(ERA5)and the Japanese Reanalysis for Three Quarters of a Century(JRA-3Q))to investigate the shift changes in precipitation in NEC around 2000 and associated water vapor transport.The analysis identified a pivotal interdecadal shift in 1998/99,transitioning from moderate increases(17.5 mm/10 yr during 1980-1998)to accelerated but more variable precipitation growth(85.4 mm/10 yr post-1999).While the mean precipitation during the post-shift period decreased,enhanced anticyclonic circulation amplified moisture divergence over continental NEC,redirecting vapor flux toward coastal regions.Crucially,trajectory analysis demonstrated regime-dependent moisture sourcing:midlatitude westerlies dominated during wet extremes(44% of trajectories in 1998),whereas East Asian monsoon flows prevailed in drought years(36% of trajectories in 2007).The post-1998 period exhibited increased reliance on localized recycling(45%of mid-tropospheric trajectories),reflecting weakened monsoonal inflow.These findings highlight NEC’s growing vulnerability to competing moisture pathways and atmospheric blocking-a dual mechanism that explains rising extremes despite declining mean precipitation.By reconciling dataset discrepancies(ERA5 vs.JRA-3Q trends)and elucidating circulation-precipitation linkages,this work provides actionable insights for climate-resilient agriculture in NEC’s water-stressed ecosystems.
文摘Objective:To investigate the distribution of Traditional Chinese Medicine(TCM)constitution among night-shift nurses at a public tertiary-level Class A hospital,thereby identifying new approaches for developing effective interventions to enhance their health status.Methods:A total of 601 nurses employed at a public tertiary-level Class A hospital from August 2024 to August 2025 participated in the survey.Analysis was conducted using the Traditional Chinese Medicine Constitution Questionnaire.Results:The most prevalent TCM constitution types among night-shift nurses were Yang Deficiency Constitution(50.4%),Yin Deficiency Constitution(49.8%),Qi Deficiency Constitution(45.4%),and Phlegm-Dampness Constitution(45.1%).Conclusion:A high proportion of clinical night-shift nursing staff exhibit imbalanced constitution types,severely impacting their physical and mental health.Nursing administrators should implement targeted TCM constitution-based health maintenance and regulation to improve the health status of nursing personnel.
文摘As global climate change intensifies,alpine plants are facing dual pressures of habitat loss and rapid environmental degradation.As one of the world's most biodiverse countries,China's potential shifts in alpine plant distribution and their profound impact on fragile ecosystems have become a focus of ecological research and conservation efforts,with increasing urgency.Meconopsis,a typical representative of Chinese alpine plants,exhibits diverse adaptability,making it an ideal model for studying how alpine species respond to extreme environmental changes.A lack of comprehensive genus-level analyses may hinder the development of long-term conservation and management strategies.Given the genus's ecological importance,vulnerability,and the risk of trait homogenization in genus-level modeling,there is an urgent need to assess its future distribution patterns,migration trends,and adaptive mechanisms based on habitat classification.In this study,we employed the Maxent model,integrating multidimensional environmental variables,to develop genus-level models and representative habitat-based models(forest,meadows,and periglacial).Results indicate a northwestward expansion and southeastward contraction of suitable habitats under future climate scenarios,with migration patterns in latitude and elevation showing stage-specific characteristics.Key environmental factors varied across models but were mostly associated with seasonal growth traits and microhabitat conditions,highlighting both the universal ecological requirements and niche differentiation within Meconopsis.Based on these findings,we propose a dynamic conservation strategy framework informed by stage-specific responses and habitat differences.Future efforts should focus on incorporating alpine-specific environmental variables and optimizing specimen collection strategies to enhance model performance and support landscape planning and biodiversity conservation.
基金supported by the National Natural Science Foundation(NSF)of China(62475265,22031009,22075282,12404064)the National Key Research and Development Program of China(2021YFB3601501)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1170000)NSF of Fujian Province(2023J01212,2024J08106).
文摘Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=Sr,Ba,Ca),we reveal that conventional thermal expansion theory cannot adequately explain these phenomena.Instead,our frozen phonon analysis identifies local electron-phonon coupling as the dominant mechanism,where anisotropic thermal vibrations selectively distort the asymmetric Eu-5d potential well that arises from the dopant’s coordination environment.This distortion manifests through the temperature-sensitiveΔ_(f−d) parameter governing the 5d→4f transition energy,directly controlling spectral shifts.Our findings establish a universal framework for HIEPS in rare-earth phosphors and enable a Δ_(f−d)-guided strategy for designing thermally stable phosphors.
基金Supported by the School-level Project of Sichuan Minzu College(XYZB2017ZB).
文摘Research on tourism climate comfort is undergoing a paradigm shift from classic static assessment to intelligent dynamic sensing.Early models(such as temperature-humidity index and tourism climate index)established based on data of meteorological stations laid the foundation for the discipline but were unable to meet the dynamic demands of climate change,spatial heterogeneity,and individual experience.Global climate change is reshaping the landscape of tourism comfort and driving the assessment to shift towards future risk prediction.Downscaling technology becomes the key to connecting global scenarios and local assessments.Remote sensing and Internet of Things technologies have constructed a"sky-ground"collaborative sensing network,achieving a revolution in data acquisition.Artificial intelligence and big data analysis serve as the intelligent core to drive research from description to prediction.The new paradigm has significant potential in improving assessment accuracy and timeliness,but also faces challenges such as data integration,model interpretability,interdisciplinary integration,and ethical privacy.In the future,it is needed to develop interpretable AI,construct climate digital twins,and promote full-chain coupling research.This transformation is not merely an upgrade of methods,but a fundamental shift in the study of philosophy from an"environment-centered"perspective to an"experience-centered"one,providing key scientific support for sustainable tourism.
文摘Sleep is a biological phenomenon with highly conserved evolutionary characteristics.The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults get at least 7 hours of sleep per night[1].However,the stress caused by fast-paced life often leads to sleep deprivation(SD).SD is strongly associated with damage to the auditory system[2,3].Obstructive sleep apnea-hypopnea syndrome(OSAHS)is a common sleep disorder.Clinical observations indicate that some patients with OSAHS experience persistent hearing loss accompanied by tinnitus and other symptoms[4].More than 61.8%of patients with sudden deafness experienced SD[5].
文摘Academic journals,consulting firms,and mainstream media have often published“predictions”about the future develop-ment of medical and health care.These publications often emphasize the potential of cutting-edge scientific or technical breakthroughs.Health Care Science looks at the problem from another perspective.We focus on how these changes enter the health system,how they operate in the real world,and how they reshape the organization and governance of medical services.At the beginning of 2026,we envision the following three major shifts that will reshape healthcare.
文摘At the start of China’s 15th Five-Year Plan period(2026–2030),signals from March’s Two Sessions point to a subtle but notable change in direction.Policymakers are moving beyond an emphasis on headline growth figures and are instead concentrating on building a more resilient economic foundation in a volatile global environment.
文摘Potassium(K)is known to enhance the catalytic performance of Fe-based catalysts in the reverse water-gas shift(rWGS)reaction,which is highly relevant during Fischer-Tropsch(FT)synthesis of CO_(2)-H_(2) mixtures.To elucidate the mechanistic role of K promoter,we employed density functional theory(DFT)calculations in conjunction with microkinetic modelling for two representative surface terminations of Hägg carbide(χ-Fe_(5)C_(2)),i.e.,(010)and(510).K_(2)O results in stronger adsorption of CO_(2)and H_(2) on Hägg carbide and promotes C–O bond dissociation of adsorbed CO_(2)by increasing the electron density on Fe atoms close to the promoter oxide.The increased electron density of the surface Fe atoms results in an increased electron-electron repulsion with bonding orbitals of adsorbed CO_(2).Microkinetics simulations predict that K_(2)O increases the CO_(2)conversion during CO_(2)-FT synthesis.K_(2)O also enhances CO adsorption and dissociation,facilitating the formation of methane,used here as a proxy for hydrocarbons formation during CO_(2)-FT synthesis.CO dissociation and O removal via H_(2)O compete as the rate-controlling steps in CO_(2)-FT.
基金supported by the National Natural Science Foundation of China(32273037 and 32102636)the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030007)+4 种基金Laboratory of Lingnan Modern Agriculture Project(NT2021007)the Guangdong Science and Technology Innovation Leading Talent Program(2019TX05N098)the 111 Center(D20008)the double first-class discipline promotion project(2023B10564003)the Department of Education of Guangdong Province(2019KZDXM004 and 2019KCXTD001).
文摘A switch from avian-typeα-2,3 to human-typeα-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus.Some H9N2 viruses exhibit a preference for binding to human-typeα-2,6 receptors.This identifies their potential threat to public health.However,our understanding of the molecular basis for the switch of receptor preference is still limited.In this study,we employed the random forest algorithm to identify the potentially key amino acid sites within hemagglutinin(HA),which are associated with the receptor binding ability of H9N2 avian influenza virus(AIV).Subsequently,these sites were further verified by receptor binding assays.A total of 12 substitutions in the HA protein(N158D,N158S,A160 N,A160D,A160T,T163I,T163V,V190T,V190A,D193 N,D193G,and N231D)were predicted to prefer binding toα-2,6 receptors.Except for the V190T substitution,the other substitutions were demonstrated to display an affinity for preferential binding toα-2,6 receptors by receptor binding assays.Especially,the A160T substitution caused a significant upregulation of immune-response genes and an increased mortality rate in mice.Our findings provide novel insights into understanding the genetic basis of receptor preference of the H9N2 AIV.
基金Sponsored by Natural Science Foundation of Heilongjiang Provincial(Grant No.LH2023F033)Science and Technology Innovation Talent Project of Harbin(Grant No.2022CXRCCG006).
文摘The current dialogue system can be sensitive to the emotions in the user's words,generating an empathetic response to help calm the user's emotions.But in some cases,eliciting empathetic responses may not adequately mitigate the adverse effects that the current conversation topic is having on users.The dialogue system will continue the conversation with the user under this uncomfortable topic,which will lead to a worse chat situation or even an impasse.To solve this problem,a dialogue system that can change the topic autonomously according to the user's emotions is proposed in this paper.Specifically,the dialogue system first collects the emotional semantic information of the users and then detects it according to the emotion classification module.Once the detection results show that the user is in a bad mood,the topic change module selects a new topic from the context to shift to and generates a response.This not only helps to calm the user's mood but also move the conversation to a new area,steering the user away from the uncomfortable topic.The experimental results show that the proposed method incurs less cost in terms of content quality,but improves the emotional perception ability.Additionally,it endows the dialogue system with the ability to change the topic,and improves the user's dialogue experience.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1602500)the National Natural Science Foundation of China(Grant Nos.1236040286,12474250,12174316,12464036,and12404306)+1 种基金the Young Teachers Scientific Research Ability Promotion Plan of Northwest Normal University(Grant No.NWNU-LKQN2020-10)the Funds for Innovative Fundamental Research Group Project of Gansu Province(Grant No.20JR5RA541)。
文摘The transition energies of the 1s^(2)2s^(2)S_(1/2)→1s^(2)2p^(2)p_(1/2,3/2)transitions in Li-like Th87+ions were calculated by combining the multi-configuration Dirac-Hartree-Fock(MCDHF)method with the model-quantum electrodynamics(modelQED)approach.The effects of electron correlation,Breit interaction,and QED effects were analyzed in detail.The isotope shifts,including the mass shifts and field shifts,due to the 2s2S_(1/2)→2p^(2)P_(1/2,3/2)transitions were then calculated using two different methods,namely,the MCDHF method and the finite-field method.The results show that these two methods are in excellent agreement.
文摘With the continuous improvement of the medical industry’s requirements for the professional capabilities of nursing talents,traditional nursing teaching models can hardly meet the needs of complex nursing work in neurology.This paper focuses on nursing education for neurology nursing students and explores the construction of the“one-on-one”teaching model,aiming to achieve a paradigm shift in nursing education.By analyzing the current status of neurology nursing education,this paper identifies the problems in traditional teaching models.Combining the advantages of the“one-on-one”teaching model,it elaborates on the construction path of this model from aspects such as the selection and training of teaching instructors,the design of teaching content,the innovation of teaching methods,and the improvement of the teaching evaluation system.The research shows that the“one-on-one”teaching model can significantly enhance nursing students’mastery of professional knowledge,clinical operation skills,communication skills,and emergency response capabilities,as well as strengthen their professional identity and sense of responsibility.It provides an effective way to cultivate high-quality nursing talents who can meet the needs of neurology nursing work and promotes the innovative development of nursing education.
基金Hangzhou Philosophy and Social Science Planning Program(24JD15)。
文摘National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire protection technologies has opened avenues for China to access a wealth of documents and codes,which are crucial in crafting regulations and developing a robust,scientific framework for fire code formulation.However,the translation of these codes into Chinese has been inadequate,thereby diminishing the benefits of technological exchange and collaborative learning.This underscores the necessity for comprehensive research into code translation,striving for higher-quality translations guided by established translation theories.In this study,we translated the initial segment of the NFPA 1 Fire Code into Chinese and examined both the source text and target text through the lens of Translation Shift Theory,a concept introduced by Catford.The conclusion culminated in identifying four key shifts across various linguistic levels:lexis,sentences,and groups,to ensure an accurate and precise translation of fire codes.This study offers a through and lucid explanation of how the translator integrates Catford’s theories to solve technical challenges in NFPA 1 Fire Code translation,and establish essential standards for construction translation practices.
