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Complete f-Moment Convergence for Sung’s Type Weighted Sums of Negatively Superadditive Dependent Random Variables
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作者 HU Xueping WANG Liuliu +1 位作者 HU Ke XU Zhonghao 《应用概率统计》 北大核心 2025年第4期585-601,共17页
In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergen... In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergence of NSD random variables.We establish and improve a general result on the complete f-moment convergence for Sung’s type randomly weighted sums of NSD random variables under some general assumptions.As an application,we show the complete consistency for the randomly weighted estimator in a nonparametric regression model based on NSD errors. 展开更多
关键词 Marcinkiewicz-Zygmund inequality Rosenthal-type inequality Sung’s type randomly weighted sums negatively superadditive dependent random variables complete f-moment convergence
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Confidence Intervals for the Reliability of Dependent Systems:Integrating Frailty Models and Copula-Based Methods
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作者 Osnamir E.Bru-Cordero Cecilia Castro +1 位作者 Victor Leiva Mario C.Jaramillo-Elorza 《Computer Modeling in Engineering & Sciences》 2025年第5期1401-1431,共31页
Most reliability studies assume large samples or independence among components,but these assump-tions often fail in practice,leading to imprecise inference.We address this issue by constructing confidence intervals(CI... Most reliability studies assume large samples or independence among components,but these assump-tions often fail in practice,leading to imprecise inference.We address this issue by constructing confidence intervals(CIs)for the reliability of two-component systems with Weibull distributed failure times under a copula-frailty framework.Our construction integrates gamma-distributed frailties to capture unobserved heterogeneity and a copula-based dependence structure for correlated failures.The main contribution of this work is to derive adjusted CIs that explicitly incorporate the copula parameter in the variance-covariance matrix,achieving near-nominal coverage probabilities even in small samples or highly dependent settings.Through simulation studies,we show that,although traditional methods may suffice with moderate dependence and large samples,the proposed CIs offer notable benefits when dependence is strong or data are sparse.We further illustrate our construction with a synthetic example illustrating how penalized estimation can mitigate the issue of a degenerate Hessian matrix under high dependence and limited observations,so enabling uncertainty quantification despite deviations from nominal assumptions.Overall,our results fill a gap in reliability modeling for systems prone to correlated failures,and contribute to more robust inference in engineering,industrial,and biomedical applications. 展开更多
关键词 Censored data copula methods dependent failure times interval estimation Weibull distribution
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Transformation City Golmud’s evolution from a resource-dependent city into an eco-friendly highland
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作者 Guo Xixian 《China Report ASEAN》 2025年第11期49-51,共3页
In the vast hinterland of the Qinghai-Xizang Plateau in western China,a profound green transformation is advancing quietly.On the vast Gobi Desert,arrays of solar panels resemble a shimmering silver sea.White wind tur... In the vast hinterland of the Qinghai-Xizang Plateau in western China,a profound green transformation is advancing quietly.On the vast Gobi Desert,arrays of solar panels resemble a shimmering silver sea.White wind turbines stand tall against the sky,with their blades swirling slowly in the wind.Golmud,a city in west China’s Qinghai Province formerly known for its abundant natural resources. 展开更多
关键词 resource dependent city natural resources gobi desertarrays Qinghai Xizang Plateau solar panels green transformation wind turbines eco friendly city
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Finite-Time Stability of Impulsive and Switched Hybrid Systems With Delay-Dependent Impulses
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作者 Taixiang Zhang Jinde Cao +1 位作者 Mahmoud Abdel-Aty Ardak Kashkynbayev 《IEEE/CAA Journal of Automatica Sinica》 2025年第2期466-468,共3页
Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimati... Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently. 展开更多
关键词 finite time stability delay dependent impulses hybrid systemswhen switching dynamics impulsive dynamics impulsive switched hybrid systems switched systems lyapunov method
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Construction of a Prognostic Model for Lysosome-dependent Cell Death in Gastric Cancer Based on Single-cell RNA-seq and Bulk RNA-seq Data
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作者 Peng Ni Kaixin Guo +6 位作者 Tianyi Liang Xinshuang Fan Yanqiao Hua Yangye Gao Shuaiyin Chen Guangcai Duan Rongguang Zhang 《Biomedical and Environmental Sciences》 2025年第4期416-432,共17页
Objective To identify prognostic genes associated with lysosome-dependent cell death(LDCD)in patients with gastric cancer(GC).Methods Differentially expressed genes(DEGs)were identified using The Cancer Genome Atlas-S... Objective To identify prognostic genes associated with lysosome-dependent cell death(LDCD)in patients with gastric cancer(GC).Methods Differentially expressed genes(DEGs)were identified using The Cancer Genome Atlas-Stomach Adenocarcinoma.Weighted gene co-expression network analysis was performed to identify the key module genes associated with LDCD score.Candidate genes were identified by DEGs and key module genes.Univariate Cox regression analysis,and least absolute shrinkage and selection operator regression and multivariate Cox regression analyses were performed for the selection of prognostic genes,and risk module was established.Subsequently,key cells were identified in the single-cell dataset(GSE183904),and prognostic gene expression was analyzed.Cell proliferation and migration were assessed using the Cell Counting Kit-8 assay and the wound healing assay.Results A total of 4,465 DEGs,95 candidate genes,and 4 prognostic genes,including C19orf59,BATF2,TNFAIP2,and TNFSF18,were identified in the analysis.Receiver operating characteristic curves indicated the excellent predictive power of the risk model.Three key cell types(B cells,chief cells,and endothelial/pericyte cells)were identified in the GSE183904 dataset.C19orf59 and TNFAIP2 exhibited predominant expression in macrophage species,whereas TNFAIP2 evolved over time in endothelial/pericyte cells and chief cells.Functional experiments confirmed that interfering with C19orf59 inhibited proliferation and migration in GC cells.Conclusion C19orf59,BATF2,TNFAIP2,and TNFSF18 are prognostic genes associated with LDCD in GC.Furthermore,the risk model established in this study showed robust predictive power. 展开更多
关键词 Gastric cancer Lysosomal dependent cell death Single-cell analysis Risk model Immune infiltration
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Efficacy and mechanism of Shugan Jieyu combined with sertraline in alcohol-dependent patients with depression:A randomized clinical study
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作者 Yan Zhang Hao-Yu Xing Juan Yan 《World Journal of Psychiatry》 2025年第12期283-288,共6页
BACKGROUND Proper antidepressant use can improve mood and reduce desire to drink alcohol in alcohol-induced-affective-disorder patients.Shugan Jieyu capsules(SJC)have various impacts on the central nervous system,prod... BACKGROUND Proper antidepressant use can improve mood and reduce desire to drink alcohol in alcohol-induced-affective-disorder patients.Shugan Jieyu capsules(SJC)have various impacts on the central nervous system,producing antidepressant effects.Traditional Chinese medicine(including Shugan Jieyu)is highly therapeutic in treating alcohol dependence,with few side-effects.However,research on its combination with Western antidepressants(e.g.,sertraline)to improve patients’depression is insufficient.AIM To evaluate the clinical efficacy and safety of SJC combined with sertraline vs sertraline monotherapy in alcohol-dependent patients with comorbid depression.METHODS We conducted a randomized,double-blind,placebo-controlled trial.Sixty patients(aged 18-65 years)were randomly assigned to two groups(n=30 per group).Primary outcome:Hamilton Depression Rating Scale(HAMD)-17 changes over 6 weeks.Benzodiazepines were permitted for severe insomnia.RESULTS The HAMD-17 score of the study(vs control)group was lower at treatment weeks 2,4,and 6(P<0.05).Regarding intra-group comparisons,the study group’s HAMD score was significantly lower than that before treatment from week 2(P<0.05),while that of the control group was significantly lower than that before treatment from week 4(P<0.05).The study and control groups’total efficacy rates were 90%and 73.3%,respectively,showing a significant difference in efficacy(χ^(2)=4.812,P=0.028).No significant difference was observed in adverse reactions’incidence between the groups at treatment weeks 2,4,and 6(P>0.05).CONCLUSION SJC-sertraline combination therapy accelerates depressive symptom relief(by 2 weeks)and improves response rates(+16.7%)in alcohol-dependent patients,without increasing adverse events.Clinical outcomes suggest potential synergistic mechanisms,though no biomarker analyses were performed. 展开更多
关键词 Shugan Jieyu capsules SERTRALINE Alcohol dependence DEPRESSION EFFICACY MECHANISM
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Functional redundancy of three mitochondrial Mg^(2+)/Mn^(2+)dependent protein phosphatases(PPMs)in Toxoplasma gondii
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作者 Kaiyin SHENG Xueqiu CHEN +6 位作者 Yimin YANG Jie XIA Kaiyue SONG Chaoqun YAO Yi YANG Aifang DU Guangxu MA 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 2025年第4期405-408,共4页
Toxoplasma gondii is a single-celled parasite that infects nearly all warm-blooded animals,including humans(Montoya and Liesenfeld,2004).It occurs worldwide and can persist for a lifetime in mammals.Humans get infecte... Toxoplasma gondii is a single-celled parasite that infects nearly all warm-blooded animals,including humans(Montoya and Liesenfeld,2004).It occurs worldwide and can persist for a lifetime in mammals.Humans get infected by eating undercooked meat of animals containing the tissue cysts of this parasite.In immune-competent individuals,T. 展开更多
关键词 functional redundancy tissue cysts Toxoplasma gondii mitochondrial mg mn dependent protein phosphatases toxoplasma gondii
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Synchronous Membership Function Dependent Event-Triggered H∞Control of T-S Fuzzy Systems Under Network Communications
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作者 Bo-Lin Xu Chen Peng Wen-Bo Xie 《IEEE/CAA Journal of Automatica Sinica》 2025年第5期1041-1043,共3页
Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants a... Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants and fuzzy controllers.This makes the classic parallel distribution compensation(PDC)control infeasible.To overcome this situation,a novel method for reconstructing the membership functions'grades is proposed,which synchronizes the time scales.Then,the membership function dependent method is adopted to introduce asynchronous errors and detailed membership function information.For the event-triggered control strategy,a series of robust H∞stable conditions in LMI form are derived.Finally,a simulation of a practical system is used to demonstrate the method proposed in this letter can reduce conservatism. 展开更多
关键词 fuzzy plants controller synthesis problem network communicationsthe event triggered control reconstructing membership functionsgrades synchronizes time scalesthenthe synchronous membership functions membership function dependent method
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Complete q-Order Moment Convergence of Moving Average Processes Generated by Negatively Dependent Random Variables under Sub-Linear Expectations
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作者 Mingzhou XU 《Journal of Mathematical Research with Applications》 2025年第3期395-410,共16页
Assume that{a_(i),−∞<i<∞}is an absolutely summable sequence of real numbers.We establish the complete q-order moment convergence for the partial sums of moving average processes{X_(n)=Σ_(i=−∞)^(∞)a_(i)Y_(i+... Assume that{a_(i),−∞<i<∞}is an absolutely summable sequence of real numbers.We establish the complete q-order moment convergence for the partial sums of moving average processes{X_(n)=Σ_(i=−∞)^(∞)a_(i)Y_(i+n),n≥1}under some proper conditions,where{Yi,-∞<i<∞}is a doubly infinite sequence of negatively dependent random variables under sub-linear expectations.These results extend and complement the relevant results in probability space. 展开更多
关键词 moving average processes negatively dependent random variables complete moment convergence sub-linear expectations
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Applying the Liouville–Lanczos method of time-dependent density-functional theory to warm dense matter
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作者 Zhandos A.Moldabekov Sebastian Schwalbe +3 位作者 Thomas Gawne Thomas R.Preston Jan Vorberger Tobias Dornheim 《Matter and Radiation at Extremes》 2025年第4期44-57,共14页
Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instr... Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory. 展开更多
关键词 ab initio dynamic structure factors dsf Liouville Lanczos method simulating ds ab initio methodslinear response warm dense matter time dependent density functional theory density response properties
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Layer-dependent exciton dynamics in InSe/WS_(2)heterostructures
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作者 Siyao Li Yufan Wang +9 位作者 Zhiqiang Ming Yong Liu Lanyu Huang Siman Liu Jialong Li Yulin Chen Zhoujuan Xu Zeyu Liu Danliang Zhang Xiao Wang 《Chinese Physics B》 2025年第9期622-628,共7页
Understanding interlayer charge transfer is crucial for elucidating interface interactions in heterostructures.As the layer number can significantly influence the interface coupling and band alignment,the charge trans... Understanding interlayer charge transfer is crucial for elucidating interface interactions in heterostructures.As the layer number can significantly influence the interface coupling and band alignment,the charge transfer behaviors can be largely regulated.Here,we constructed two-dimensional(2D)heterostructures consisting of monolayer WS_(2)and few-layer InSe to investigate the impact of InSe thickness on exciton dynamics.We performed photoluminescence(PL)spectroscopy and lifetime measurements on pristine few-layer InSe and the heterostructures with different InSe thicknesses.For pristine InSe layers,we found a non-monotonic layer dependence on PL lifetime,which can be attributed to the interplay between the indirect-to-direct bandgap transition and surface recombination effects.For heterostructures,we demonstrated that the type I band alignment of the heterostructure facilitates electron and hole transfer from monolayer WS_(2)to InSe.As the InSe layer number increases,the reduction in conduction band minimum(CBM)enhances the driving force for charge transfer,thereby improving the transfer efficiency.Furthermore,we fabricated and characterized a WS_(2)/InSe optoelectronic device.By analyzing bias voltage dependent PL spectra,we further demonstrated that the trions in WS_(2)within the heterostructure are positively charged(X^(+)),and their emission intensity can be efficiently modulated by applying different biases.This study not only reveals the layer-dependent characteristics of band alignment and interlayer charge transfer in heterostructures but also provides valuable insights for the applications of 2D semiconductors in optoelectronic devices. 展开更多
关键词 EXCITON layer dependence charge transfer band alignment
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Parameter-Dependent Superconducting Transition Temperature in a Sign-Problem-Free Bilayer Model
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作者 Runyu Ma Zenghui Fan +1 位作者 Tianxing Ma Congjun Wu 《Chinese Physics Letters》 2025年第11期253-258,共6页
Recent discovery of high transition temperature superconductivity in La_(3)Ni_(2)O_(7) has sparked renewed theoretical and experimental interests in unconventional superconductivity. It is crucial to understand the in... Recent discovery of high transition temperature superconductivity in La_(3)Ni_(2)O_(7) has sparked renewed theoretical and experimental interests in unconventional superconductivity. It is crucial to understand the influence of various factors on its superconductivity. By refining the determinant quantum Monte Carlo algorithm, we characterize the parameter dependence of the superconducting transition temperature within a bilayer Hubbard model, which is sign-problem-free at arbitrary filling. A striking feature of this model is its similarity to the bilayer nickelate-based superconductor La_(3)Ni_(2)O_(7), where superconductivity emerges from the bilayer NiO_(2) planes.We find that interlayer spin-exchange J is critical to interlayer pairing, and that on-site interaction U contributes negatively to superconductivity at low doping levels but positively at high doping levels. Our findings can provide a reference for the next step in theoretical research on nickelate-based superconductors. 展开更多
关键词 superconducting transition temperature parameter dependence unconventional superconductivity bilayer hubbard model site interaction interlayer spin exchange understand influence various factors
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Anomalous temperature-dependent strength and the operative slip modes in an extruded Mg-Y sheet
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作者 Yingbo Zhang Ran Ni +6 位作者 Carl J.Boehlert Bo Chen Yanqin Chai Bo Gao Hao Zhou Qudong Wang Dongdi Yin 《Journal of Materials Science & Technology》 2025年第26期177-195,共19页
This work is intended to further understand the controversial temperature dependencies of various slip modes in Mg alloys,and their effects on the mechanical properties at high temperature(HT).A systematical and stati... This work is intended to further understand the controversial temperature dependencies of various slip modes in Mg alloys,and their effects on the mechanical properties at high temperature(HT).A systematical and statistical investigation on the temperature-dependent macroscopic deformation behavior and the corresponding grain-scale slip activity was performed for both an extruded Mg-10Y(wt.%)sheet and a pure Mg sheet during tension at 25-300℃.The alloy’s strength increased by up to 44 MPa(14.0%)at HT compared to that at 25℃and this was accompanied by decreased pyramidal II(c+a)slip activity;both phenomena were opposite to that for pure Mg.The critical resolved shear stress(CRSS)ratios were estimated based on the~1700 sets of observed slip traces,and a positive temperature-dependent CRSS_(pyr II)/CRSS_(bas)was found in Mg-10Y.Compared to pure Mg,Mg-10Y exhibited pronounced strain hard-ening at HT due to enhanced slip-slip interactions,including multiple slip and cross slip,increased GND accumulation,and Y solute-dislocation interactions.The significant pyramidal II(c+a)slip activity(up to 30%frequency),its thermal hardening and pronounced strain hardening nature are proposed to be the key reasons for the observed anomalous strength increase in Mg-10Y.The grain-scale experimental evidence for(c+a)dislocation activity and its correlation to mechanical properties were revealed in this study and compared to recent atomic-scale simulations. 展开更多
关键词 Mg-RE alloy Anomalous temperature dependency CRSS Slip trace analysis Pyramidal(c+a)slip
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Size-dependent strong metal-support interaction modulation of Pt/CoFe_(2)O_(4) catalysts
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作者 Yangyang Li Jingyi Yang +1 位作者 Botao Qiao Tao Zhang 《Chinese Journal of Catalysis》 2025年第2期292-302,共11页
Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance... Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance of supported metal catalysts.This is particularly true for single-atom catalysts(SACs)and pseudo-single-atom catalysts(pseudo-SACs),where all metal atoms are dispersed on,and interact directly with the support.Consequently,the MSI of SACs and pseudo-SACs are theoretically more sensitive to modulation compared to that of traditional nanoparticle catalysts.In this work,we experimentally demonstrated this hypothesis by an observed size-dependent MSI modulation.We fabricated CoFe_(2)O_(4) supported Pt pseudo-SACs and nanoparticle catalysts,followed by a straightforward water treatment process.It was found that the covalent strong metal-support interaction(CMSI)in pseudo-SACs can be weakened,leading to a significant activity improvement in methane combustion reaction.This finding aligns with our recent observation of CoFe_(2)O_(4) supported Pt SACs.By contrast,the MSI in Pt nanoparticle catalyst was barely affected by the water treatment,giving rise to almost unchanged catalytic performance.This work highlights the critical role of metal size in determining the MSI modulation,offering a novel strategy for tuning the catalytic performance of SACs and pseudo-SACs by fine-tuning their MSIs. 展开更多
关键词 Strongmetal-support interaction Single-atom catalyst Pseudo-single-atom catalyst Size dependence Pt/CoFe_(2)O_(4)catalyst
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Bifidobacterium longum subsp.infantis CCFM1269 promotes intestinal barrier and release of IFN-β through TLR4-TRIF dependent way in growing mice
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作者 Mengfan Ding Bo Yang +7 位作者 Bowen Li Haiqin Chen Renqiang Yu RPaul Ross Catherine Stanton Shilong Jiang Jianxin Zhao Wei Chen 《Food Science and Human Wellness》 2025年第1期345-360,共16页
Bifidobacterium longum subsp.infantis is a commensal bacterium that predominates in the infant gut,playing a critical role in both preventing foreign infections and facilitating immune development.This study aimed to ... Bifidobacterium longum subsp.infantis is a commensal bacterium that predominates in the infant gut,playing a critical role in both preventing foreign infections and facilitating immune development.This study aimed to explore the effects of B.longum subsp.infantis supplementation on interferon-beta(IFN-β)secretion and intestinal barrier improvement in growing mice.Female and male mice were orally administered either saline or B.longum subsp.infantis CCFM1269 or I5TI(1×10^(9) CFU/mice per day,n=8)from 1-week-age until 3-,4-,and 5-week-age.RNA sequencing analysis revealed that CCFM1269 exhibited potential antiviral capacity through increasing 2'-5'oligoadenylate synthetase(OAS).Additionally,CCFM1269 supplementation significantly increased colonic IFN-β levels which combined with OAS in 3-week-old female and male mice by activating the TLR4-TRIF-dependent signaling pathway.However,this effect was not observed in 4-and 5-week-old mice.Furthermore,both CCFM1269 were found to modulate the gut microbiota composition and enhance the intestinal barrier function in 3-,4-,and 5-week-old mice.In summary,the results of this study suggested that B.longum subsp.infantis CCFM1269 promoting intestinal barrier and releasing IFN-β in growing mice was in a strain-specific and time-dependent manner. 展开更多
关键词 Bifidobacterium longum subsp.infantis Intestinal barrier interferon-beta(IFN-β)secretion Age dependence
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主梁断面三自由度耦合非线性颤振分析 被引量:1
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作者 胡朋 袁邦荣 +2 位作者 韩艳 李凯 陈旭 《工程力学》 北大核心 2026年第1期174-184,共11页
为分析主梁断面三自由度耦合非线性颤振特性并考察侧向自由度对非线性颤振特性的影响,以某典型箱梁断面为例,建立了一种考虑18个幅变颤振导数的三自由度耦合非线性颤振分析方法。采用强迫振动数值模拟技术识别了该断面不同折减风速和不... 为分析主梁断面三自由度耦合非线性颤振特性并考察侧向自由度对非线性颤振特性的影响,以某典型箱梁断面为例,建立了一种考虑18个幅变颤振导数的三自由度耦合非线性颤振分析方法。采用强迫振动数值模拟技术识别了该断面不同折减风速和不同振幅下的18个幅变颤振导数。基于识别的幅变颤振导数采用建立的三自由度耦合非线性颤振分析方法计算了该断面的非线性颤振响应,并与自由振动数值模拟结果进行对比,验证了幅变颤振导数识别结果和非线性颤振分析方法的准确性。量化了侧向自由度对非线性颤振的影响,并揭示了其影响机制。研究结果表明,侧向自由度的参与不仅在一定程度上降低颤振临界风速,也会增大非线性颤振的稳态振幅,且振幅越大这种增幅越明显,这主要是因为侧向自由度的引入降低了扭转模态分支的阻尼比,进而降低了系统的稳定性。进一步地,组成扭转模态分支阻尼比的各项中,扭转-竖向耦合气动阻尼比与扭转-侧向耦合气动阻尼比项均不利于扭转模态运动的稳定。 展开更多
关键词 非线性颤振 箱梁 侧向振动 幅变颤振导数 数值模拟
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非成员依赖如何影响农民合作社公司化
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作者 张舰 王永胜 《中国农村经济》 北大核心 2026年第1期137-160,共24页
农业合作化是实现农业强国的重要实践方向和推动力量。然而,中国农民合作社公司化现象普遍,公司化使合作社这种有别于公司的组织形态难以发挥作用。本文旨在从合作社依赖对象(成员与非成员)视角理解合作社公司化的内在机理。本文构建了... 农业合作化是实现农业强国的重要实践方向和推动力量。然而,中国农民合作社公司化现象普遍,公司化使合作社这种有别于公司的组织形态难以发挥作用。本文旨在从合作社依赖对象(成员与非成员)视角理解合作社公司化的内在机理。本文构建了一个包含异质性成员、非成员依赖与合作社公司化的分析框架,分析发现:当合作社对非成员的依赖程度很高时,即当合作社转入的土地和收购非成员农产品很多(从而越不依赖于成员)时,合作社理事会就会有动机和激励扩大其持股比例与合作社盈余按股分红比例,合作社公司化程度也会提高。数值模拟分析和利用调研数据进行的计量分析均证实了非成员依赖与合作社公司化之间的这种因果关系。本文的研究结论不仅能为理解中国合作社公司化现象提供新视角,也能为农业经营主体变革背景下合作社如何进一步处理好效率与公平问题提供政策参考。 展开更多
关键词 农民合作社 非成员依赖 合作社公司化 盈余分配
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Reliability assessment considering dependent competing failure process and shifting-threshold 被引量:11
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作者 苏春 瞿众洲 郝会兵 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期52-56,共5页
The reliability assessment problem for products subject to degradation and random shocks is investigated. Two kinds of probabilistic models are constructed, in which the dependent competing failure process is consider... The reliability assessment problem for products subject to degradation and random shocks is investigated. Two kinds of probabilistic models are constructed, in which the dependent competing failure process is considered. First, based on the assumption of cumulative shock, the probabilistic models for hard failure and soft failure are built respectively. On this basis, the dependent competing failure model involving degradation and shock processes is established. Furthermore, the situation of the shifting-threshold is also considered, in which the hard failure threshold value decreases to a lower level after the arrival of a certain number of shocks. A case study of fatigue crack growth is given to illustrate the proposed models. Numerical results show that shock has a significant effect on the failure process; meanwhile, the effect will be magnified when the value of the hard threshold shifts to a lower level. 展开更多
关键词 degradation hard failure dependent competing failure process cumulative shock model shifting-threshold
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边缘计算中依赖任务的联合调度与缓存优化策略
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作者 张文柱 唐文迪 +1 位作者 刘润滋 边跃伟 《计算机工程与应用》 北大核心 2026年第4期96-110,共15页
为了解决依赖任务结构带来的调度复杂性及缓存资源利用不足的问题,提出了一种联合调度与缓存的优化策略。构建边、端计算模型,并以最小化系统总时延、能耗和负载方差增量为优化目标;设计一种支持动态依赖的层级化虚拟任务调度与优化算法... 为了解决依赖任务结构带来的调度复杂性及缓存资源利用不足的问题,提出了一种联合调度与缓存的优化策略。构建边、端计算模型,并以最小化系统总时延、能耗和负载方差增量为优化目标;设计一种支持动态依赖的层级化虚拟任务调度与优化算法,有效减少跨节点通信和资源消耗,同时确定全局最优调度序列;将该优化问题分解为资源分配和卸载及缓存决策两个子问题,利用凸优化理论求解资源分配,并引入基于任务类型价值的服务缓存策略,以提升缓存效率;设计一种任务卸载与服务缓存协同优化算法,通过迭代获得任务的最优卸载决策和缓存策略。仿真结果表明,该协同优化算法能够充分利用缓存资源,在确保依赖任务顺序的同时,有效降低系统时延与能耗,并提升系统的负载均衡性。 展开更多
关键词 边缘计算 依赖任务 任务调度 服务缓存
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Substrate-dependent photoreactivities of BiOBr nanoplates prepared at different pH values 被引量:5
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作者 艾智慧 王吉玲 张礼知 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2145-2154,共10页
In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1(BOB-1) degr... In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1(BOB-1) degraded salicylic acid more effectively than did those obtained at pH 3(BOB-3),but the order of their photocatalytic activities in rhodamine B(RhB) degradation were reversed. Electrochemical Mott–Schottky and zeta-potential measurements showed that BOB-1 had a more positive valence band and lower surface charge,leading to superior photocatalytic activity in salicylic acid degradation under visible light. However,BOB-3 was more powerful in RhB degradation because larger numbers of superoxide radicals were generated via electron injection from the excited RhB to its more negative conduction band under visible-light irradiation; this was confirmed using active oxygen species measurements and electron spin resonance analysis. This study deepens our understanding of the origins of organic-pollutant-dependent photoreactivities of semiconductors,and will help in designing highly active photocatalysts for environmental remediation. 展开更多
关键词 DEGRADATION Visible light Substrate dependent photoreactivity Bismuth oxybromide nanoplate Rhodamine B Salicylic acid
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