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McKean-Vlasov Backward Stochastic Differential Equations with Weak Monotonicity Coefficients
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作者 FU Zongkui FEI Dandan GUO Shanshan 《应用数学》 北大核心 2026年第1期98-107,共10页
This paper deals with Mckean-Vlasov backward stochastic differential equations with weak monotonicity coefficients.We first establish the existence and uniqueness of solutions to Mckean-Vlasov backward stochastic diff... This paper deals with Mckean-Vlasov backward stochastic differential equations with weak monotonicity coefficients.We first establish the existence and uniqueness of solutions to Mckean-Vlasov backward stochastic differential equations.Then we obtain a comparison theorem in one-dimensional situation. 展开更多
关键词 McKean-Vlasov backward stochastic differential equation Weak monotonicity condition Comparison theorem
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DPIL-Traj: Differential Privacy Trajectory Generation Framework with Imitation Learning
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作者 Huaxiong Liao Xiangxuan Zhong +4 位作者 Xueqi Chen Yirui Huang Yuwei Lin Jing Zhang Bruce Gu 《Computers, Materials & Continua》 2026年第1期1530-1550,共21页
The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location re... The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location reidentification and correlation attacks.To address these challenges,privacy-preserving trajectory generation methods are critical for applications relying on sensitive location data.This paper introduces DPIL-Traj,an advanced framework designed to generate synthetic trajectories while achieving a superior balance between data utility and privacy preservation.Firstly,the framework incorporates Differential Privacy Clustering,which anonymizes trajectory data by applying differential privacy techniques that add noise,ensuring the protection of sensitive user information.Secondly,Imitation Learning is used to replicate decision-making behaviors observed in real-world trajectories.By learning from expert trajectories,this component generates synthetic data that closely mimics real-world decision-making processes while optimizing the quality of the generated trajectories.Finally,Markov-based Trajectory Generation is employed to capture and maintain the inherent temporal dynamics of movement patterns.Extensive experiments conducted on the GeoLife trajectory dataset show that DPIL-Traj improves utility performance by an average of 19.85%,and in terms of privacy performance by an average of 12.51%,compared to state-of-the-art approaches.Ablation studies further reveal that DP clustering effectively safeguards privacy,imitation learning enhances utility under noise,and the Markov module strengthens temporal coherence. 展开更多
关键词 PRIVACY-PRESERVING trajectory generation differential privacy imitation learning Markov chain
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Determination of Phenolic Hydroxyl Content in Poly(phenylene oxide)by Differential Ultraviolet Spectrophotometry
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作者 Qin-Yu Yan Shun-Gang Song +4 位作者 Bu-Jie Zhou Jing Hu Lian-Fang Feng Xue-Ping Gu Cai-Liang Zhang 《Chinese Journal of Polymer Science》 2026年第1期79-86,I0010,共9页
Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its... Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques. 展开更多
关键词 Poly(phenylene oxide) Phenolic hydroxyl Redistribution differential UV spectrophotometry
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Structural Reliability Analysis Based on Differential Evolution Algorithm and Hypersphere Integration
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作者 CHEN Zhenzhong HAN Zhuo +4 位作者 WANG Peiyu PAN Qianghua LI Xiaoke GAN Xuehui CHEN Ge 《Journal of Donghua University(English Edition)》 2026年第1期118-130,共13页
In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order relia... In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision. 展开更多
关键词 reliability analysis design point positioning differential evolution algorithm hypersphere integration
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WPT-FOD Method Based on Channel Differential Response and Dynamic Threshold
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作者 XU Xihong LIU Fuqian XIA Chenyang 《南方能源建设》 2026年第1期127-138,共12页
[Objective]As wireless power transfer(WPT)technology is increasingly deployed in scenarios such as electric vehicles,metallic foreign objects in the WPT area may cause local overheating and energy loss.Existing method... [Objective]As wireless power transfer(WPT)technology is increasingly deployed in scenarios such as electric vehicles,metallic foreign objects in the WPT area may cause local overheating and energy loss.Existing methods still suffer from poor edge/corner sensitivity,misjudgment due to fixed thresholds,and limited ability to extract position information.This work proposes a wireless power transfer-foreign object detection(WPT-FOD)method based on channel differential response and a dynamic-threshold corner-enhancement strategy,aiming to improve detection sensitivity,localization accuracy,and robustness without altering the overall coil layout.[Method]A multi-channel detection coil array is designed,and the self-inductance disturbance response of each channel coil is modeled.A channel-difference mapping mechanism is introduced to build a 2-D sensitivity matrix to characterize spatial position correlation.A corner-enhancement algorithm is developed to weight and amplify the collaborative response of adjacent channels,and a dynamic threshold adjustment mechanism is integrated to adapt to varying interference levels.Validation is carried out on a self-built 64-channel FOD platform by moving a typical metallic foreign object across central,edge,and corner regions,and by conducting comparative tests under different interference intensities.[Result]When a typical metallic foreign object moves to corner regions,the self-inductance disturbance of the detection coil increases from less than 0.02μH to more than 0.06μH,significantly enhancing the discrimination capability at corners.Under varying interference strengths,the dynamic threshold mechanism reduces the number of false positives from 13 to 2,demonstrating good environmental adaptability and stability.[Conclusion]By combining channel differential response,corner enhancement,and dynamic thresholding,the proposed WPT-FOD effectively mitigates edge/corner blind spots and fixed-threshold misjudgment,while providing localization capability and robustness.It markedly improves the accuracy of metallic foreign object detection in WPT systems and offers a feasible path and method reference for the safe application and engineering deployment of WPT systems. 展开更多
关键词 electric vehicles wireless charging foreign object detection channel differential response corner enhancement algorithm
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Stochastic Differential Equation-Based Dynamic Imperfect Maintenance Strategy for Wind Turbine Systems
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作者 Hongsheng Su Zhensheng Teng Zihan Zhou 《Energy Engineering》 2026年第2期229-258,共30页
Addressing the limitations of inadequate stochastic disturbance characterization during wind turbine degradation processes that result in constrained modeling accuracy,replacement-based maintenance practices that devi... Addressing the limitations of inadequate stochastic disturbance characterization during wind turbine degradation processes that result in constrained modeling accuracy,replacement-based maintenance practices that deviate from actual operational conditions,and static maintenance strategies that fail to adapt to accelerated deterioration trends leading to suboptimal remaining useful life utilization,this study proposes a Time-Based Incomplete Maintenance(TBIM)strategy incorporating reliability constraints through stochastic differential equations(SDE).By quantifying stochastic interference via Brownian motion terms and characterizing nonlinear degradation features through state influence rate functions,a high-precision SDE degradation model is constructed,achieving 16%residual reduction compared to conventional ordinary differential equation(ODE)methods.The introduction of age reduction factors and failure rate growth factors establishes an incomplete maintenance mechanism that transcends traditional“as-good-as-new”assumptions,with the TBIM model demonstrating an additional 8.5%residual reduction relative to baseline SDE approaches.A dynamic maintenance interval optimization model driven by dual parameters—preventive maintenance threshold R_(p) and replacement threshold R_(r)—is designed to achieve synergistic optimization of equipment reliability and maintenance economics.Experimental validation demonstrates that the optimized TBIM extends equipment lifespan by 4.4%and reducesmaintenance costs by 4.16%at R_(p)=0.80,while achieving 17.2%lifespan enhancement and 14.6%cost reduction at R_(p)=0.90.This methodology provides a solution for wind turbine preventive maintenance that integrates condition sensitivity with strategic foresight. 展开更多
关键词 Stochastic differential equations(SDE) imperfect maintenance condition-based maintenance(CBM) time-based maintenance(TBM) reliability constraint wind turbine
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All entire solutions of Fermat type difference-differential equations of one variable
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作者 XU Ling LUO Run-zi CAO Ting-bin 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期509-522,共14页
The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]^(2)+[p2(z)f(z)+p3(z)f′(z)]^(2)=p(z);or[p1(z)f(z)]^(2)+[p2(z)f′(z)+p3(z)f(z+c)]^(... The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]^(2)+[p2(z)f(z)+p3(z)f′(z)]^(2)=p(z);or[p1(z)f(z)]^(2)+[p2(z)f′(z)+p3(z)f(z+c)]^(2)=p(z)or[p1(z)f′(z)]^(2)+[p2(z)f(z+c)+p3(z)f(z)]^(2)=p(z);where c is a nonzero complex number,p1;p2 and p3 are polynomials in C satisfying p1p3■0;and p is a nonzero irreducible polynomial in C. 展开更多
关键词 difference equations difference-differential equation Fermat type equation entire solutions
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An Explicit Difference Scheme with High Accuracy and Branching Stability for Solving Parabolic Partial Differential Equation 被引量:4
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作者 马明书 王肖凤 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期98-103,共6页
This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△... This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△x4). The stability condition is r=a△t/△x2<1/2. 展开更多
关键词 parabolic type equation explicit difference scheme high accuracy branching stability truncation er
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A Family of High_order Accuracy Explicit Difference Schemes for Solving 2-D Parabolic Partial Differential Equation 被引量:4
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作者 任宗修 陈贞忠 王肖凤 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第3期57-61,共5页
A family of high_order accuracy explicit difference schemes for solving 2_dimension parabolic P.D.E. are constructed. Th e stability condition is r=Δt/Δx 2=Δt/Δy 2【1/2 and the truncation err or is O(Δt 3+Δx... A family of high_order accuracy explicit difference schemes for solving 2_dimension parabolic P.D.E. are constructed. Th e stability condition is r=Δt/Δx 2=Δt/Δy 2【1/2 and the truncation err or is O(Δt 3+Δx 4). 展开更多
关键词 D parabolic P.D.E high_order accuracy explic it difference scheme
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Numerical Methods for Boundary Value Problems in Variable Coefficient Ordinary Differential Equations 被引量:1
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作者 ZHAO Ting-ting CAI Wei-yun 《Chinese Quarterly Journal of Mathematics》 2025年第3期295-303,共9页
In order to solve the problem of the variable coefficient ordinary differen-tial equation on the bounded domain,the Lagrange interpolation method is used to approximate the exact solution of the equation,and the error... In order to solve the problem of the variable coefficient ordinary differen-tial equation on the bounded domain,the Lagrange interpolation method is used to approximate the exact solution of the equation,and the error between the numerical solution and the exact solution is obtained,and then compared with the error formed by the difference method,it is concluded that the Lagrange interpolation method is more effective in solving the variable coefficient ordinary differential equation. 展开更多
关键词 Variable coefficient ordinary differential equations Lagrange interpolation difference methods
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Method for Estimating the State of Health of Lithium-ion Batteries Based on Differential Thermal Voltammetry and Sparrow Search Algorithm-Elman Neural Network 被引量:1
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作者 Yu Zhang Daoyu Zhang TiezhouWu 《Energy Engineering》 EI 2025年第1期203-220,共18页
Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,curr... Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity degradation.Additionally,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model performance.To address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural network.Firstly,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity curves.Next,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network model.To validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging dataset.The experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%. 展开更多
关键词 Lithium-ion battery state of health differential thermal voltammetry Sparrow Search Algorithm
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How has"Henan No.2 Spindle"advanced through specialization,refinement,differentiation,and innovation——An Interview with Mr.Cao Xiucheng from Henan No.2 Textile Machinery Co.,Ltd.
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作者 Niu Fang Zhao Xinhua 《China Textile》 2026年第1期5-7,共3页
At the start of the new year,Cao Xiucheng,Chairman of Henan No.2 Textile Machinery Co.,Ltd.,was on his way to visit clients when he kept receiving urgent calls from the Xinyang production base regarding order scheduli... At the start of the new year,Cao Xiucheng,Chairman of Henan No.2 Textile Machinery Co.,Ltd.,was on his way to visit clients when he kept receiving urgent calls from the Xinyang production base regarding order scheduling.It turned out that since the end of 2025,the company had successively secured bulk spindle orders from overseas clients in Bangladesh and other countries,coupled with continuous urgent requests for orders from domestic manufacturers.Faced with such a production peak right at the beginning of the year,Mr.Cao Xiucheng admitted,“It was truly unexpected.” 展开更多
关键词 innovation differentiATION textile machinery production peak SPECIALIZATION REFINEMENT SPINDLE order schedulingit
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Sex differences in retinal neurovascular changes in type 1 diabetes without retinopathy
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作者 Yao Chen Qian-Xin Li +3 位作者 Tong Zhang Yao Tan Rong-Han Wu Ling Gao 《International Journal of Ophthalmology(English edition)》 2026年第3期509-516,共8页
AIM:To investigate the sex-specific correlation between systemic factors and retinal neurovascular alterations in individuals with type 1 diabetes mellitus(T1DM)who do not exhibit signs of diabetic retinopathy(DR).MET... AIM:To investigate the sex-specific correlation between systemic factors and retinal neurovascular alterations in individuals with type 1 diabetes mellitus(T1DM)who do not exhibit signs of diabetic retinopathy(DR).METHODS:A cohort participant without DR diagnosed with T1DM,underwent comprehensive ophthalmologic evaluation,optical coherence tomography angiography retinal structural and microvascular density analysis,and systemic parameter assessment.Multiple linear regression analysis was used to investigate the impact of systemic parameters on retinal alterations in distinct gender groups.RESULTS:A total of 182 individuals were included,consisting of 85 males(mean age 23.28±12.75y)and 97 females(mean age 22.98±13.68y).Males exhibited significantly greater thickness in both the internal retinal layer and the entire retina compared to females(P<0.01),whereas females had higher densities of deep retinal vessels and choroidal capillaries(P<0.05).Additionally,glycemic control was found to have a notable influence on retinal thickness in males(P<0.05),while insulin function had a more pronounced impact on retinal structure in females(P<0.01).Furthermore,a significant correlation was observed between thyroid function markers and retinal parameters in both male and female(P<0.05).CONCLUSION:Sex differences in alterations in retinal structure and microcirculation are observed in individuals with T1DM prior to the development of clinical DR,with a noted association between these changes and systemic parameters. 展开更多
关键词 type 1 diabetes mellitus diabetic retinopathy gender differences optical coherence tomography angiography
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Lithospermic Acid Promotes Osteoblast Proliferation and Differentiation through the Wnt/β-Catenin Signaling Pathway
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作者 Jianfeng Wang Zhongqing Hu +5 位作者 Jiandong Guo Xin Jin Lei Cai Jian Li Jinxi Zhang Dongan He 《BIOCELL》 2026年第2期128-147,共20页
Objectives Therapeutic strategies for enhancing bone regeneration and combating osteoporosis remain a significant unmet medical need.This study aims to elucidate Lithospermic acid(LA)’s regulatory effects on osteobla... Objectives Therapeutic strategies for enhancing bone regeneration and combating osteoporosis remain a significant unmet medical need.This study aims to elucidate Lithospermic acid(LA)’s regulatory effects on osteoblast proliferation and differentiation,investigating its viability as a bone-healing agent.Methods This study employed various cellular and molecular biology experiments to assess the effects of LA on the viability,proliferation,cell cycle,apoptosis,differentiation,mineralization,and migration of MC3T3-E1 osteoblasts.Immunofluorescence and Western blot analyses were conducted to detect the expression of proteins related to the Wnt/β-catenin signaling pathway,investigating the regulatory mechanisms by which LA promotes osteoblast proliferation and differentiation.Additionally,Wnt inhibitor dickkopf-1(DKK-1)andβ-catenin-silenced cell models were used to further validate the role of LA in modulating this signaling pathway.Results LA significantly promoted osteoblast proliferation without apparent cytotoxicity.Flow cytometry showed that LA regulated the cell cycle by reducing G0/G1 phase arrest and promoting G2/M phase progression.Western blot results indicated that LA upregulated the expression of proteins associated with cell proliferation and enhanced osteoblast differentiation and mineralization.Immunofluorescence and Western blot analyses further confirmed that LA markedly increased the expression of Wnt andβ-catenin,facilitatingβ-catenin nuclear translocation.Treatment with the DKK-1 inhibitor significantly diminished the proliferative and differentiation-promoting effects of LA,confirming the critical role of this pathway.β-catenin knockdown experiments further substantiated its central role in LA-mediated regulation.Conclusion This study confirms that LA promotes osteoblast proliferation,differentiation,mineralization,and migration by activating the Wnt/β-catenin signaling pathway. 展开更多
关键词 Lithospermic acid OSTEOBLASTS cell proliferation cell differentiation Wnt/β-catenin signaling pathway
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Cedrol ameliorates ulcerative colitis via myeloid differentiation factor 2-mediated inflammation suppression,with barrier restoration and microbiota modulation
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作者 Yi-Qing Zhao Yu Zhang +2 位作者 Yan Qin Rui-Ya Zhang Jun-Ping Wang 《World Journal of Gastroenterology》 2026年第2期135-151,共17页
BACKGROUND Ulcerative colitis(UC)is a chronic and treatment-resistant disorder requiring potent therapeutics that are effective and safe.Cedrol(CE)is a bioactive natural product present in many traditional Chinese med... BACKGROUND Ulcerative colitis(UC)is a chronic and treatment-resistant disorder requiring potent therapeutics that are effective and safe.Cedrol(CE)is a bioactive natural product present in many traditional Chinese medicines.It is known for its suppression of inflammation and mitigation of oxidative stress.Its therapeutic efficacy and mechanistic underpinnings in UC remain uncharacterized.AIM To investigate the therapeutic potential and mechanisms of CE in UC.METHODS The anti-inflammatory activity and intestinal barrier-repairing effects of CE were assessed in a dextran sulfate sodium-induced murine colitis model.Network pharmacology was employed to predict potential targets and pathways.Then molecular docking and dynamics simulations were utilized to confirm a stable interaction between CE and the toll-like receptor 4(TLR4)/myeloid differentiation factor 2(MD2)complex.The anti-inflammatory mechanisms were further verified using in vitro assays.Additionally,the gut microbiota composition was analyzed via 16S rRNA gene sequencing.RESULTS CE significantly alleviated colitis symptoms,mitigated histopathological damage,and suppressed inflammation.Moreover,CE restored intestinal barrier integrity by enhancing mucus secretion and upregulating tight junction proteins(zonula occludens 1,occludin,claudin-1).Mechanistically,CE stably bound to MD2,inhibiting lipopolysaccharide-induced TLR4 signaling in RAW264.7 cells.This led to suppression of the downstream mitogen-activated protein kinase and nuclear factor kappa B signaling pathways,downregulating the expression of tumor necrosis factor-alpha,interleukin-1β,and interleukin-6.Gut microbiota analysis revealed that CE reversed dextran sulfate sodium-induced dysbiosis with significant enrichment of butyrogenic Christensenella minuta.CONCLUSION CE acted on MD2 to suppress proinflammatory cascades,promoting mucosal barrier reconstitution and microbiota remodeling and supporting its therapeutic use in UC. 展开更多
关键词 CEDROL Ulcerative colitis Toll-like receptor 4 Myeloid differentiation factor 2 Signaling pathways Gut microbiota
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OPTIMAL POINT-WISE ERROR ESTIMATE OF TWO SECOND-ORDER ACCURATE FINITE DIFFERENCE SCHEMES FOR THE HEAT EQUATION WITH CONCENTRATED CAPACITY
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作者 Leilei Shi Tingchun Wang Xuanxuan Zhou 《Journal of Computational Mathematics》 2026年第1期61-83,共23页
In this paper,we propose and analyze two second-order accurate finite difference schemes for the one-dimensional heat equation with concentrated capacity on a computa-tional domain=[a,b].We first transform the target ... In this paper,we propose and analyze two second-order accurate finite difference schemes for the one-dimensional heat equation with concentrated capacity on a computa-tional domain=[a,b].We first transform the target equation into the standard heat equation on the domain excluding the singular point equipped with an inner interface matching(IIM)condition on the singular point x=ξ∈(a,b),then adopt Taylor’s ex-pansion to approximate the IIM condition at the singular point and apply second-order finite difference method to approximate the standard heat equation at the nonsingular points.This discrete procedure allows us to choose different grid sizes to partition the two sub-domains[a,ξ]and[ξ,b],which ensures that x=ξ is a grid point,and hence the pro-posed schemes can be generalized to the heat equation with more than one concentrated capacities.We prove that the two proposed schemes are uniquely solvable.And through in-depth analysis of the local truncation errors,we rigorously prove that the two schemes are second-order accurate both in temporal and spatial directions in the maximum norm without any constraint on the grid ratio.Numerical experiments are carried out to verify our theoretical conclusions. 展开更多
关键词 Heat equation with concentrated capacity Finite difference scheme Inner interface matching condition Unconditional convergence Optimal error estimate
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Urban-rural differences in residential energy-use behavior and energy-saving awareness:Evidence from a Chinese megacity
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《建筑节能(中英文)》 2026年第2期150-150,共1页
Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing s... Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing studies often lack comparative analysis of urban-rural differences and tend to focus excessively on behavior patterns while neglecting the dimension of energysaving awareness.With China’s urbanization rate reaching 66.16%,understanding such regional disparities has become increasingly important.To address these research gaps,this study conducts a large-scale survey on space cooling behaviors among residents in Beijing,a representative Chinese megacity.It should be noted that living standards in such megacities are generally higher than the national average,which may shape distinctive energy-use profiles.Analyzing 1573valid samples(1064 urban/442 rural)in 2024,this study employed K-Prototypes and K-Modes clustering to identify typical cooling behavior and energy-saving awareness pattems,followed by Kendall/Chi-square correlation tests and XGBoost importance analysis to determine key influencing factors,with subsequent urban-rural comparative analysis.Results indicate that urban residents are primarily heat-sensitive or heat-tolerant,with a secondary patten of mid-low temperature preference,and generally exhibit long cooling durations;rural behavior is dominated by heat-tolerant type,followed by heat-sensitive,mid-low temperature preference,and never-on types as secondary patterns;both urban and rural areas exhibit energy-savingawareness characterized by low consumption-lowwillingness,though urban areas show marginally higher motivation;energy-saving awareness correlates with cooling behavior in rural areas,but this relationship weakens significantly in urban contexts. 展开更多
关键词 behavior patterns such regional disparities energy saving awareness residential energy use behavior climate change urban rural differences China Beijing
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Lamina combination characteristics and differential shale oil enrichment mechanisms of continental organic-rich shale:A case study of Triassic Yanchang Formation Chang 73 sub-member,Ordos Basin,NW China 被引量:2
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作者 NIU Xiaobing LYU Chengfu +5 位作者 FENG Shengbin ZHOU Qianshan XIN Honggang XIAO Yueye LI Cheng DAN Weidong 《Petroleum Exploration and Development》 2025年第2期316-329,共14页
The lamina(combination)types,reservoir characteristics and shale oil occurrence states of organic-rich shale in the Triassic Yanchang Formation Chang 73 sub-member in the Ordos Basin were systematically investigated t... The lamina(combination)types,reservoir characteristics and shale oil occurrence states of organic-rich shale in the Triassic Yanchang Formation Chang 73 sub-member in the Ordos Basin were systematically investigated to reveal the main controlling factors of shale oil occurrence under different lamina combinations.The differential enrichment mechanisms and patterns of shale oil were discussed using the shale oil micro-migration characterization and evaluation methods from the perspectives of relay hydrocarbon supply,stepwise migration,and multi-stage differentiation.The results are obtained in five aspects.First,Chang 73 shale mainly develops five types of lamina combination,i.e.non-laminated shale,sandy laminated shale,tuffaceous laminated shale,mixed laminated shale,and organic-rich laminated shale.Second,shales with different lamina combinations are obviously different in the reservoir space.Specifically,shales with sandy laminae and tuffaceous laminae have a large number of intergranular pores,dissolution pores and hydrocarbon generation-induced fractures.The multi-scale pore and fracture system constitutes the main place for liquid hydrocarbon occurrence.Third,the occurrence and distribution of shale oil in shale with different lamina combinations are jointly controlled by organic matter abundance,reservoir property,thermal evolution degree,mineral composition and laminae scale.The micro-nano-scale pore-fracture networks within shales containing rigid laminae,particularly sandy and tuffaceous laminations,primarily contain free-state light hydrocarbon components.In contrast,adsorption-phase heavy hydrocarbon components predominantly occupy surfaces of organic matter assemblages,clay mineral matrices,and framework mineral particulates.Fourth,there is obvious shale oil micro-migration between shales with different lamina combinations in Chang 73.Generally,such micro-migration is stepwise in a sequence of organic-rich laminated shale→tuffaceous laminated shale→mixed laminated shale→sandy lamiated shale→non-laminated shale.Fifth,the relay hydrocarbon supply of organic matter under the control of the spatial superposition of shales with various laminae,the stepwise migration via multi-scale pore and fracture network,and the multi-differentiation in shales with different lamina combinations under the control of organic-inorganic interactions fundamentally decide the differences of shale oil components between shales with different lamina combinations. 展开更多
关键词 organic-rich shale lamina combination characteristics differential enrichment mechanism shale oil Chang 73 sub-member Triassic Yanchang Formation Ordos Basin
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New exact solutions to some difference differential equations 被引量:15
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作者 王振 张鸿庆 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第10期2210-2215,共6页
In this paper, we use our method to solve the extended Lotka-Volterra equation and discrete KdV equation. With the help of Maple, we obtain a number of exact solutions to the two equations including soliton solutions ... In this paper, we use our method to solve the extended Lotka-Volterra equation and discrete KdV equation. With the help of Maple, we obtain a number of exact solutions to the two equations including soliton solutions presented by hyperbolic functions of sinh and cosh, periodic solutions presented by trigonometric functions of sin and cos, and rational solutions. This method can be used to solve some other nonlinear difference-differential equations. 展开更多
关键词 difference differential equation soliton solutions Lotka-Volterra equation discrete KdV equation
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