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宣木瓜多糖缓解PRV感染小鼠脑和肝脏中炎症反应
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作者 舒瑞腾 吴家乐 +5 位作者 王紫苇 孙雯捷 刘畅 李磊 叶鹏飞 曹迷霞 《现代畜牧兽医》 2026年第1期1-7,共7页
试验旨在明确宣木瓜多糖对伪狂犬病毒(pseudorabies virus,PRV)感染小鼠脑部和肝脏炎症反应的调节作用,并结合差异KEGG通路机制探索其抗炎靶点。试验将50只SPF级昆明小鼠(雌、雄各半)随机分为5组,每组10只小鼠,以50~200 mg/kg的宣木瓜... 试验旨在明确宣木瓜多糖对伪狂犬病毒(pseudorabies virus,PRV)感染小鼠脑部和肝脏炎症反应的调节作用,并结合差异KEGG通路机制探索其抗炎靶点。试验将50只SPF级昆明小鼠(雌、雄各半)随机分为5组,每组10只小鼠,以50~200 mg/kg的宣木瓜多糖处理PRV感染小鼠,并设PRV组和对照组,于试验第7天解剖并取脑、肝脏组织,通过ELISA检测炎症因子与炎症效应分子活性,同时对肝脏组织开展转录组测序,进行GO、KEGG富集分析及GSEA。结果显示,50~200 mg/kg宣木瓜多糖可改善PRV感染引发的炎症因子失衡,降低小鼠脑、肝脏组织中肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-18(IL-18)等促炎因子及单核细胞趋化蛋白-1(MCP-1)、趋化因子(C-C基序)配体5(CCL5)、C-X-C趋化因子配体10(CXCL10)等趋化因子的含量;能够抑制炎症效应分子环氧化酶-2(COX-2)、诱导型一氧化氮合酶(iNOS)的活性。转录组层面,宣木瓜多糖作用后PRV感染小鼠肝脏共产生2998个差异表达基因;差异基因在生物过程(细胞过程、生物调节)、分子功能(结合、催化活性)、细胞组分(细胞解剖实体)中显著富集;KEGG分析与GSEA结果一致显示,差异基因显著富集于补体与凝血级联反应、造血细胞谱系、细胞外基质(ECM)-受体相互作用、黏着斑、磷脂酰肌醇3激酶-蛋白激酶B(PI3K-Akt)及丝裂原活化蛋白激酶(MAPK)信号通路。研究表明,宣木瓜多糖可通过调控补体与凝血级联反应、PI3K-Akt及MAPK等关键信号通路,靶向调控炎症相关差异基因的表达,进而发挥对PRV感染引发的脑部及肝脏过度炎症反应的抑制作用,维持机体炎症稳态。 展开更多
关键词 宣木瓜多糖 prv 炎症反应 肝脏
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Strong Laws of Large Numbers for Sequences of Blockwise m-Dependent and Sub-Orthogonal Random Variables under Sublinear Expectations 被引量:1
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作者 Jialiang FU 《Journal of Mathematical Research with Applications》 2026年第1期103-118,共16页
In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random vari... In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case. 展开更多
关键词 sublinear expectations strong law of large numbers blockwise m-dependent suborthogonal random variables
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A data-and expert-driven framework for establishing land cover-related essential variables for SDG monitoring and assessment
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作者 Hao Wu Ping Zhang +6 位作者 Jun Chen Songnian Li Jing Li Shu Peng Dongyang Hou Jun Zhang Hao Chen 《Geography and Sustainability》 2026年第1期236-246,共11页
Sustained and spatially explicit monitoring of the United Nations 2030 Agenda for Sustainable Development is critical for effectively tracking progress toward the global Sustainable Development Goals(SDGs).Although la... Sustained and spatially explicit monitoring of the United Nations 2030 Agenda for Sustainable Development is critical for effectively tracking progress toward the global Sustainable Development Goals(SDGs).Although land cover information has long been recognized as an essential component for monitoring SDGs,a standardized scientific framework for identifying and prioritizing land cover related essential variables does not exist.Therefore,we propose a novel expert-and data-driven framework for identifying,refining,and selecting a priority list of Essential Land cover-related Variables for SDGs(ELcV4SDGs).This framework integrates methods including expert knowledge-based analysis,clustering of variables with similar attributes,and quantified index calculation to establish the priority list.Applying the framework to 15 specific SDG indicators,we found that the ELcV4SDGs priority list comprises three main categories,type and structure,pattern and intensity,and process and evolution of land cover,which are further divided into 19 subcategories and ultimately encompass 50 general variables.The ELcV4SDGs will support detailed spatial monitoring and enhance their scientific applications for SDG monitoring and assessment,thereby guiding future SDG priority actions and informing decision-making to advance the 2030 SDGs agenda at local,national,and global levels. 展开更多
关键词 Essential variable Land cover SDG Spatial monitoring and assessment Interactive analysis Refinement and selection
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PRV感染小鼠三叉神经节细胞后通过RIG-Ⅰ信号通路调控Ⅰ型干扰素分泌
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作者 廖正波 汤德元 +7 位作者 曾智勇 王彬 黄涛 陈旭 袁盛林 何松 周飘 毛茵茗 《中国兽医学报》 北大核心 2025年第2期255-265,共11页
为探究伪狂犬病病毒(pseudorabies virus, PRV)感染小鼠三叉神经节(TG)细胞后对其抗病毒免疫信号通路及Ⅰ型干扰素因子(IFN-Ⅰ)的影响。本试验使用1 MOI PRV接种感染TG原代细胞,使用106.29TCID50PRV滴鼻感染小鼠,使用实时荧光定量PCR(qP... 为探究伪狂犬病病毒(pseudorabies virus, PRV)感染小鼠三叉神经节(TG)细胞后对其抗病毒免疫信号通路及Ⅰ型干扰素因子(IFN-Ⅰ)的影响。本试验使用1 MOI PRV接种感染TG原代细胞,使用106.29TCID50PRV滴鼻感染小鼠,使用实时荧光定量PCR(qPCR)、Western blot和ELISA等技术检测小鼠TG原代细胞不同攻毒时间点及体内攻毒组和对照组的基因转录、蛋白表达及IFN-α和IFN-β的分泌情况。结果显示,PRV感染小鼠TG原代细胞后引起RIG-I、MAVS和IRF3的基因及蛋白表达变化,诱导了体内外IRF3和IκBα的磷酸化。ELISA结果显示,PRV感染后可调控小鼠TG原代细胞及小鼠TG内IFN-α和IFN-β的分泌。使用siRNA干扰TG细胞内RIG-Ⅰ表达后Western blot检测RIG-Ⅰ信号通路相关蛋白表达结果及IFN-α和IFN-β的分泌情况。结果显示,siRIG-Ⅰ成功干扰TG细胞内RIG-Ⅰ蛋白表达,并引起下游MAVS和IRF3等蛋白表达发生变化,同时调控TG细胞内IFN-α和IFN-β的分泌。研究结果表明,PRV感染可诱导小鼠TG原代细胞及小鼠TG内RIG-Ⅰ的表达,并通过RIG-Ⅰ-MAVS-IRF3信号轴调控TG细胞内IFN-Ⅰ的抗病毒免疫反应,以及PRV会抑制TG内IRF3表达,并在感染后期显著上调IFN-β的表达,这可能是PRV在感染后期导致小鼠快速死亡的重要原因。本试验揭示了PRV感染小鼠TG细胞后通过RIG-Ⅰ-MAVS-IRF3信号通路调控IFN-Ⅰ的部分抗病毒免疫机制,以及发现IRF3蛋白在体内外不同的变化趋势,为后续深入研究奠定了基础。 展开更多
关键词 prv RIG-Ⅰ IRF3 信号通路 Ⅰ型干扰素 小鼠
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基于PRV-copGFP的伪狂犬病毒快速中和抗体效价检测方法的建立
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作者 李晨雨 马琦 +7 位作者 王冰丹 王菲 冯霞 张晓光 李红霞 马晶 郝彦哲 李淑英 《病毒学报》 北大核心 2025年第3期825-834,共10页
本研究开发了一种高效且精准的伪狂犬病病毒(Pseudorabies virus, PRV)中和抗体效价检测新方法。通过同源重组和CRISPR-Cas9技术,将桡足纲绿色荧光蛋白(copepod Pontellina plumata Green Fluorescent Protein,copGFP)基因表达盒精确嵌... 本研究开发了一种高效且精准的伪狂犬病病毒(Pseudorabies virus, PRV)中和抗体效价检测新方法。通过同源重组和CRISPR-Cas9技术,将桡足纲绿色荧光蛋白(copepod Pontellina plumata Green Fluorescent Protein,copGFP)基因表达盒精确嵌入PRV基因组的UL40/41区域,经过多轮筛选与纯化,成功构建了重组病毒PRV-copGFP。生长特性对比实验表明,PRV-copGFP与野生型PRV-Bartha之间无显著差异(P>0.05)。借助CTL-ImmunoSpot?S6仪器计数表达copGFP的细胞数目,确定了最佳观测时间和最佳病毒滴度。该方法可精确计算中和抗体效价,并通过传统噬斑减少中和试验(Plaque reduction neutralization test, PRNT)进行验证。与传统方法相比,本检测方法将检测窗口缩短至10h,且通量显著提升。本方法在快速评估PRV中和抗体效价方面具有显著优势,可为PRV疫苗研发、疾病防控及相关研究提供有力的技术支持。 展开更多
关键词 伪狂犬病病毒(prv) 中和抗体效价 桡足纲绿色荧光蛋白(copGFP) 重组病毒 快速检测
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Optimizing Fine-Tuning in Quantized Language Models:An In-Depth Analysis of Key Variables
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作者 Ao Shen Zhiquan Lai +1 位作者 Dongsheng Li Xiaoyu Hu 《Computers, Materials & Continua》 SCIE EI 2025年第1期307-325,共19页
Large-scale Language Models(LLMs)have achieved significant breakthroughs in Natural Language Processing(NLP),driven by the pre-training and fine-tuning paradigm.While this approach allows models to specialize in speci... Large-scale Language Models(LLMs)have achieved significant breakthroughs in Natural Language Processing(NLP),driven by the pre-training and fine-tuning paradigm.While this approach allows models to specialize in specific tasks with reduced training costs,the substantial memory requirements during fine-tuning present a barrier to broader deployment.Parameter-Efficient Fine-Tuning(PEFT)techniques,such as Low-Rank Adaptation(LoRA),and parameter quantization methods have emerged as solutions to address these challenges by optimizing memory usage and computational efficiency.Among these,QLoRA,which combines PEFT and quantization,has demonstrated notable success in reducing memory footprints during fine-tuning,prompting the development of various QLoRA variants.Despite these advancements,the quantitative impact of key variables on the fine-tuning performance of quantized LLMs remains underexplored.This study presents a comprehensive analysis of these key variables,focusing on their influence across different layer types and depths within LLM architectures.Our investigation uncovers several critical findings:(1)Larger layers,such as MLP layers,can maintain performance despite reductions in adapter rank,while smaller layers,like self-attention layers,aremore sensitive to such changes;(2)The effectiveness of balancing factors depends more on specific values rather than layer type or depth;(3)In quantization-aware fine-tuning,larger layers can effectively utilize smaller adapters,whereas smaller layers struggle to do so.These insights suggest that layer type is a more significant determinant of fine-tuning success than layer depth when optimizing quantized LLMs.Moreover,for the same discount of trainable parameters,reducing the trainable parameters in a larger layer is more effective in preserving fine-tuning accuracy than in a smaller one.This study provides valuable guidance for more efficient fine-tuning strategies and opens avenues for further research into optimizing LLM fine-tuning in resource-constrained environments. 展开更多
关键词 Large-scale Language Model Parameter-Efficient Fine-Tuning parameter quantization key variable trainable parameters experimental analysis
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Chinese herbal extracts with antiviral activity:evaluation,mechanisms,and potential for preventing PRV,PEDV and PRRSV infections
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作者 Yumei Sun Chang Li +7 位作者 Zhongzhu Liu Wei Zeng Muhammad Jamil Ahmad Mengjia Zhang Lina Liu Shujun Zhang Wentao Li Qigai He 《Animal Diseases》 2025年第2期205-219,共15页
The rapid expansion of large-scale pig farming has brought about a surge in viral diseases with high morbidity rates and diverse manifestations.This widespread occurrence of multiple viral diseases in pig farms has in... The rapid expansion of large-scale pig farming has brought about a surge in viral diseases with high morbidity rates and diverse manifestations.This widespread occurrence of multiple viral diseases in pig farms has inflicted severe economic losses on the global swine industry.Consequently,there is an urgent need for eco-friendly and efficient antivi-ral drugs that can effectively combat viruses and prevent diseases such as PEDV,PRRSV,PRV,and other viral infections.To this end,we conducted a study on the antiviral activity and cytotoxicity of eleven different Chinese herbal extracts(CHE) against PRV.In vitro testing of several extracts,namely,Echinacea,Ilex purpurea Hassk,Ganoderma lucidum Kars,Taraxacum mongolicum,and Ilex rotunda Thunb,exhibited remarkable inhibition of PRV infection without causing any cytotoxic effects.Specifically,their antiviral selectivity indexes were significantly higher,with values ranging from 6-to 144-fold.The antiviral efficacy of five CHEs was evaluated against other RNA viruses,including PRRSV and PEDV.The extracts showed substantial inhibition of PEDV and PRRSV proliferation.Echinacea and Ilex purpurea Hassk extracts exhibited the highest virus inhibitory effects.To understand the antiviral mechanisms underlying their potent activity,a time-of-addition experiment was conducted.The results indicated that these extracts effectively targeted the early infection and postinfection stages of PRV,PEDV,and PRRSV.The study found that the Chinese herbal extracts,Echinacea and Ilex purpurea Hassk,had both direct and indirect effects on virus particles and cellular targets,demonstrating broad-spectrum antiviral activity against multiple clinical strains of PRV and PEDV.These findings provide a strong foundation for the development of herbal medicines to prevent and treat infections caused by PRV,PEDV and PRRSV in the swine industry.The identified extracts show great promise for the formulation of effective and environmentally friendly antiviral interventions. 展开更多
关键词 CHE prv PEDV PRRSV Antiviral activity
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Equivalent Conditions of Complete Convergence for Weighted Sums of Sequences of i.i.d.Random Variables under Sublinear Expectations
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作者 XU Mingzhou CHENG Kun 《应用概率统计》 北大核心 2025年第3期339-352,共14页
The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the... The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space. 展开更多
关键词 complete convergence weighted sums i.i.d.random variables sublinear expectation
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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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Influence of ambient geochemical and microbiological variables on the bacterial diversity in a cold seep ecosystem in North Indian Ocean
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作者 Delcy R.Nazareth Maria Judith Gonsalves Nitisha Sangodkar 《Geoscience Frontiers》 2025年第3期153-163,共11页
Cold seeps are oases for biological communities on the sea floor around hydrocarbon emission pathways.Microbial utilization of methane and other hydrocarbons yield products that fuel rich chemosynthetic communities at... Cold seeps are oases for biological communities on the sea floor around hydrocarbon emission pathways.Microbial utilization of methane and other hydrocarbons yield products that fuel rich chemosynthetic communities at these sites.One such site in the cold seep ecosystem of Krishna-Godavari basin(K-G basin)along the east coast of India,discovered in Feb 2018 at a depth of 1800 m was assessed for its bacterial diversity.The seep bacterial communities were dominated by phylum Proteobacteria(57%),Firmicutes(16%)and unclassified species belonging to the family Helicobacteriaceae.The surface sediments of the seep had maximum OTUs(operational taxonomic units)(2.27×10^(3))with a Shannon alpha diversity index of 8.06.In general,environmental parameters like total organic carbon(p<0.01),sulfate(p<0.001),sulfide(p<0.05)and methane(p<0.01)were responsible for shaping the bacterial community of the cold seep ecosystem in the K-G Basin.Environmental parameters play a significant role in changing the bacterial diversity richness between different cold seep environments in the oceans. 展开更多
关键词 SEDIMENTS Environmental variables PROTEOBACTERIA Cold seep ecosystem Organic matter
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A Decision Variables Classification-Based Evolutionary Algorithm for Constrained Multi-Objective Optimization Problems
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作者 Xuanxuan Ban Jing Liang +4 位作者 Kangjia Qiao Kunjie Yu Yaonan Wang Jinzhu Peng Boyang Qu 《IEEE/CAA Journal of Automatica Sinica》 2025年第9期1830-1849,共20页
Solving constrained multi-objective optimization problems(CMOPs)is a challenging task due to the presence of multiple conflicting objectives and intricate constraints.In order to better address CMOPs and achieve a bal... Solving constrained multi-objective optimization problems(CMOPs)is a challenging task due to the presence of multiple conflicting objectives and intricate constraints.In order to better address CMOPs and achieve a balance between objectives and constraints,existing constrained multi-objective evolutionary algorithms(CMOEAs)predominantly focus on devising various strategies by leveraging the relationships between objectives and constraints,and the designed strategies usually are effective for the problems with simple constraints.However,these methods most ignore the relationship between decision variables and constraints.In fact,the essence of optimization is to find appropriate decision variables to meet various complex constraints.Therefore,it is hoped that the problem can be analyzed from the perspective of decision variables,so as to obtain more excellent results.Based on the above motivation,this paper proposes a decision variables classification approach,according to the relationship between decision variables and constraints,variables are divided into constraint-related(CR)variables and constraintindependent(CI)variables.Consequently,by optimizing these two types of variables independently,the population can sustain a favorable balance between feasibility and diversity.Furthermore,specific offspring generation strategies are proposed for the two categories of decision variables in order to achieve rapid convergence while maintaining population diversity.Experimental results on 31 test problems as well as 20 real-world problems demonstrate that the proposed algorithm is competitive compared to some state-of-the-art constrained multi-objective optimization algorithms. 展开更多
关键词 Constraint-independent(CI) constrained multiobjective optimization constraint-related(CR) decision variables
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On α-Bloch Functions in Several Complex Variables
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作者 ZHU Ting YANG Liu 《Chinese Quarterly Journal of Mathematics》 2025年第1期93-102,共10页
In this paper,we establish characterizations of α-Bloch functions and little α-Bloch functions on the unit ball as well as the unit polydisk of C^(m),which generalize and improve results of Aulaskari-Lappan,Minda,Au... In this paper,we establish characterizations of α-Bloch functions and little α-Bloch functions on the unit ball as well as the unit polydisk of C^(m),which generalize and improve results of Aulaskari-Lappan,Minda,Aulaskari-Wulan,and Wu.Some examples are also given to complement our theory. 展开更多
关键词 α-Bloch function Littleα-Bloch function Several complex variables Partial derivative
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MJO年代际变化的研究进展与科学思考 被引量:1
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作者 王璐 纪小末 +3 位作者 徐邦琪 李天明 陈林 陆波 《大气科学学报》 北大核心 2026年第1期208-216,共9页
Madden-Julian Oscillation(MJO)是热带大气最重要的季节内变率模态,其年代际变化不仅反映了热带气候系统的非平稳性特征,也直接影响其作为延伸期预报因子的有效性。本文系统综述了近年来关于MJO强度和传播特征年代际变化的研究进展,并... Madden-Julian Oscillation(MJO)是热带大气最重要的季节内变率模态,其年代际变化不仅反映了热带气候系统的非平稳性特征,也直接影响其作为延伸期预报因子的有效性。本文系统综述了近年来关于MJO强度和传播特征年代际变化的研究进展,并总结了主要科学认识。结果表明,MJO在强度、传播速度和传播范围方面均存在显著的年代际变化,同时具有明显的区域性与季节性差异。强度变化最显著的区域集中在西太平洋暖池,与局地海温升高密切相关;传播速度表现为印度洋MJO东传加快而西太平洋和海洋性大陆区域减慢,其区域性差异主要归因于热带海温增暖的不对称性;传播范围受跨洋盆模态调制,尤其是大西洋多年代际振荡(Atlantic Multidecadal Oscillation,AMO),不同位相下MJO的空间范围及对流-环流耦合持续时间显著不同。MJO年代际变化受多尺度过程协同调制,包括局地海气耦合、背景环流变化及对流-环流正反馈放大等非线性过程。尽管观测与模式研究取得了进展,但在资料一致性、指标敏感性、机理归因及对气候可预报性的影响等方面仍存在不确定性。 展开更多
关键词 热带季节内振荡 年代际变化 强度 传播
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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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Complete Convergence for the Maximum Partial Sums of m-Widely Orthant Dependent Random Variables Sequences
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作者 SONG Mingzhu 《Wuhan University Journal of Natural Sciences》 2025年第6期549-557,共9页
In this paper,the author obtains complete convergence for the maximum partial sums of m-widely orthant dependent(m-WOD)random variables sequences under some general conditions.The results extend the complete convergen... In this paper,the author obtains complete convergence for the maximum partial sums of m-widely orthant dependent(m-WOD)random variables sequences under some general conditions.The results extend the complete convergence for m-WOD random variables to a much more general type complete convergence.As the sequences of m-WOD random variables represent a very broad class of dependent sequences,the results improve and generalize the corresponding ones in the literature. 展开更多
关键词 m-WOD random variables complete convergence Spitzer’s law of large numbers
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Mapping soil organic carbon in fragmented agricultural landscapes:The efficacy and interpretability of multi-category remote sensing variables
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作者 Yujiao Wei Yiyun Chen +6 位作者 Jiaxue Wang Peiheng Yu Lu Xu Chi Zhang Huanfeng Shen Yaolin Liu Ganlin Zhang 《Journal of Integrative Agriculture》 2025年第11期4395-4414,共20页
Accurately mapping the spatial distribution of soil organic carbon(SOC)is crucial for guiding agricultural management and improving soil carbon sequestration,especially in fragmented agricultural landscapes.Although r... Accurately mapping the spatial distribution of soil organic carbon(SOC)is crucial for guiding agricultural management and improving soil carbon sequestration,especially in fragmented agricultural landscapes.Although remote sensing provides spatially continuous environmental information about heterogeneous agricultural landscapes,its relationship with SOC remains unclear.In this study,we hypothesized that multi-category remote sensing-derived variables can enhance our understanding of SOC variation within complex landscape conditions.Taking the Qilu Lake watershed in Yunnan,China,as a case study area and based on 216 topsoil samples collected from irrigation areas,we applied the extreme gradient boosting(XGBoost)model to investigate the contributions of vegetation indices(VI),brightness indices(BI),moisture indices(MI),and spectral transformations(ST,principal component analysis and tasseled cap transformation)to SOC mapping.The results showed that ST contributed the most to SOC prediction accuracy,followed by MI,VI,and BI,with improvements in R2 of 29.27,26.83,19.51,and 14.43%,respectively.The dominance of ST can be attributed to the fact that it contains richer remote sensing spectral information.The optimal SOC prediction model integrated soil properties,topographic factors,location factors,and landscape metrics,as well as remote sensing-derived variables,and achieved RMSE and MAE of 15.05 and 11.42 g kg-1,and R2 and CCC of 0.57 and 0.72,respectively.The Shapley additive explanations deciphered the nonlinear and threshold effects that exist between soil moisture,vegetation status,soil brightness and SOC.Compared with traditional linear regression models,interpretable machine learning has advantages in prediction accuracy and revealing the influences of variables that reflect landscape characteristics on SOC.Overall,this study not only reveals how remote sensing-derived variables contribute to our understanding of SOC distribution in fragmented agricultural landscapes but also clarifies their efficacy.Through interpretable machine learning,we can further elucidate the causes of SOC variation,which is important for sustainable soil management and agricultural practices. 展开更多
关键词 soil organic carbon remote sensing-derived variables Shapley additive explanations efficacy and interpretability fragmented agricultural landscapes
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Methods of Selecting Adaptive Artificial Viscosity in Completely Conservative Difference Schemes for Gas Dynamics Equations in Euler Variables
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作者 Marina Ladonkina Viktoriia Podryga +1 位作者 Yury Poveshchenko Haochen Zhang 《Frontiers in Heat and Mass Transfer》 2025年第6期1789-1809,共21页
The work presents new methods for selecting adaptive artificial viscosity(AAV)in iterative algorithms of completely conservative difference schemes(CCDS)used to solve gas dynamics equations in Euler variables.These me... The work presents new methods for selecting adaptive artificial viscosity(AAV)in iterative algorithms of completely conservative difference schemes(CCDS)used to solve gas dynamics equations in Euler variables.These methods allow to effectively suppress oscillations,including in velocity profiles,as well as computational instabilities in modeling gas-dynamic processes described by hyperbolic equations.The methods can be applied both in explicit and implicit(method of separate sweeps)iterative processes in numerical modeling of gas dynamics in the presence of heat and mass transfer,as well as in solving problems of magnetohydrodynamics and computational astrophysics.In order to avoid loss of solution accuracy on spatially non-uniform grids,in this work an algorithm of grid embeddings is developed,which is applied near transition points between cells of different sizes.The developed algorithms of CCDS using the methods for AAV selection and the algorithm of grid embeddings are implemented for various iterative processes.Calculations are performed for the classical problem of decay of an arbitrary discontinuity(Sod’s problem)and the problem of propagation of two symmetric rarefaction waves in opposite directions(Einfeldt’s problem).In the case of using different methods for selecting the AAV,a comparison of the solutions of the Sod’s problem on uniform and non-uniform grids and a comparison of the solutions of the Einfeldt’s problem on a uniform grid are performed.As a result of the comparative analysis,the applicability of these methods is shown in the spatially one-dimensional case(explicit and implicit iterative processes).The obtained results are compared with the data from the literature.The results coincide with analytical solutions with high accuracy,where the relative error does not exceed 0.1%,which demonstrates the effectiveness of the developed algorithms and methods. 展开更多
关键词 Gas dynamics adaptive artificial viscosity equations in Euler variables completely conservative differ-ence schemes heat and mass transfer
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A Study of Cataclysmic Variables from the eFEDS Survey
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作者 Rui Wang Wei-Min Gu +3 位作者 Zhi-Xiang Zhang Tuan Yi Senyu Qi Xiao-Jie Xu 《Research in Astronomy and Astrophysics》 2025年第11期46-57,共12页
We present 17 cataclysmic variables(CVs) obtained from the crossmatch between the Sloan Digital Sky Survey(SDSS) and eROSITA Final Equatorial Depth Survey(eFEDS),including eight known CVs before eFEDS and nine identif... We present 17 cataclysmic variables(CVs) obtained from the crossmatch between the Sloan Digital Sky Survey(SDSS) and eROSITA Final Equatorial Depth Survey(eFEDS),including eight known CVs before eFEDS and nine identified from eFEDS.The photometric periods of four CVs are derived from the Zwicky Transient Facility and Catalina Real-Time Transient Survey.We focus on two CVs,SDSS J084309.3-014858 and SDSS J093555.0+042916,and confirm that their photometric periods correspond to the orbital periods by fitting the radial velocity curves.Furthermore,by the combination of the Gaia distance,the spectral energy distribution,and the variations of Ha emission lines,the masses of the white dwarf and the visible star can be well constrained. 展开更多
关键词 (stars:)binaries(including multiple):close (stars:)novae cataclysmic variables X-rays:binaries
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On the Spatial Distribution of Luminous Blue Variables in the Galaxy M33
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作者 A.Kostenkov S.Fabrika +6 位作者 A.Kaldybekova S.Fedorchenko Y.Solovyeva E.Dedov A.Sarkisyan A.Vinokurov O.Sholukhova 《Research in Astronomy and Astrophysics》 2025年第4期136-149,共14页
In the current paper,we present a study of the spatial distribution of luminous blue variables(LBVs)and various LBV candidates(c LBVs)with respect to OB associations in the galaxy M33.The identification of blue star g... In the current paper,we present a study of the spatial distribution of luminous blue variables(LBVs)and various LBV candidates(c LBVs)with respect to OB associations in the galaxy M33.The identification of blue star groups was based on the LGGS data and was carried out by two clustering algorithms with initial parameters determined during simulations of random stellar fields.We have found that the distribution of distances to the nearest OB association obtained for the LBV/c LBV sample is close to that for massive stars with Minit>20 M⊙and WolfRayet stars.This result is in good agreement with the standard assumption that LBVs represent an intermediate stage in the evolution of the most massive stars.However,some objects from the LBV/cLBV sample,particularly Fe II-emission stars,demonstrated severe isolation compared to other massive stars,which,together with certain features of their spectra,implicitly indicates that the nature of these objects and other LBVs/cLBVs may differ radically. 展开更多
关键词 stars:massive stars:evolution stars:winds outflows stars:variables:S Doradus (stars:)binaries:general galaxies:individual(M33)
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基于果树冠层识别的植保无人机可变角度变量喷施装置设计与试验
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作者 傅生辉 任乃旭 +3 位作者 张鑫哲 刘双喜 刘镰恺 张稳 《农业机械学报》 北大核心 2026年第3期47-56,共10页
针对当前无人机喷药喷施不均匀、雾滴飘移、肥药有效利用率低和浪费污染严重等问题,设计了一种基于果树冠层识别的植保无人机可变角度变量喷施装置。该装置通过摄像头采集果树冠层图像并传输至Jetson Orin Nano,利用ROI选取与子区间线... 针对当前无人机喷药喷施不均匀、雾滴飘移、肥药有效利用率低和浪费污染严重等问题,设计了一种基于果树冠层识别的植保无人机可变角度变量喷施装置。该装置通过摄像头采集果树冠层图像并传输至Jetson Orin Nano,利用ROI选取与子区间线扫方法实现冠层边界与果树行宽度识别,识别结果传至STM32控制器,其中冠层边界信息用于调节喷头角度,像素占比信息用于调控喷头流量,流量计与磁编码器反馈信号经模糊PID算法处理,实现喷头角度与喷施量双闭环控制。经试验验证,果树冠层边界算法离线识别率为91.58%。台架试验结果表明,该方法在果树行宽度识别中平均误差为7.32%,线性拟合R^(2)=0.91;在喷雾验证中,当喷施角度大于靶区时,调节后可使靶区外沉积数量平均降低26.61个/cm^(2),雾滴沉积数量降低51.94%。当喷施角度小于靶区时,调节后可使靶区内外部雾滴沉积数量平均提升25.37个/cm^(2),雾滴沉积数量提高54.8%。核密度估计曲线更平滑,有效改善沉积分布均匀性。田间试验结果显示:统计检验结果为t=3.29、P=0.03,达到P<0.05的统计显著水平,装置开启状态下沉积效果更优,该方法实现了基于果树行宽度可变角度变量喷施控制,可有效提高雾滴利用率,为无人机果园精准施药提供技术支持。 展开更多
关键词 植保无人机 果树行检测 可变角度变量喷雾 模糊PID 药液沉积
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