期刊文献+
共找到3,909篇文章
< 1 2 196 >
每页显示 20 50 100
Enhancing Lightweight Mango Disease Detection Model Performance through a Combined Attention Module
1
作者 Wen-Tsai Sung Indra Griha TofikIsa Sung-Jung Hsiao 《Computers, Materials & Continua》 2026年第2期986-1016,共31页
Mango is a plant with high economic value in the agricultural industry;thus,it is necessary to maximize the productivity performance of the mango plant,which can be done by implementing artificial intelligence.In this... Mango is a plant with high economic value in the agricultural industry;thus,it is necessary to maximize the productivity performance of the mango plant,which can be done by implementing artificial intelligence.In this study,a lightweight object detection model will be developed that can detect mango plant conditions based on disease potential,so that it becomes an early detection warning system that has an impact on increasing agricultural productivity.The proposed lightweight model integrates YOLOv7-Tiny and the proposed modules,namely the C2S module.The C2S module consists of three sub-modules such as the convolutional block attention module(CBAM),the coordinate attention(CA)module,and the squeeze-and-excitation(SE)module.The dataset is constructed by eight classes,including seven classes of disease conditions and one class of health conditions.The experimental result shows that the proposed lightweight model has the optimal results,which increase by 13.15% of mAP50 compared to the original model YOLOv7-Tiny.While the mAP50:95 also achieved the highest results compared to other models,including YOLOv3-Tiny,YOLOv4-Tiny,YOLOv5,and YOLOv7-Tiny.The advantage of the proposed lightweightmodel is the adaptability that supports it in constrained environments,such as edge computing systems.This proposedmodel can support a robust,precise,and convenient precision agriculture system for the user. 展开更多
关键词 Mango lightweight model combined attention module c2S module precision agriculture
在线阅读 下载PDF
Optimizing the dengue virus infection mouse model:Comparing different backgrounds and infection route for enhanced stability
2
作者 Dan Liao Ming Zhong +7 位作者 Wenjiang Zheng Zhendong Guo Ye Zhou Qiuhong Li Lijuan Qiu Liangwen Yu Haishan Long Geng Li 《Animal Models and Experimental Medicine》 2026年第1期103-114,共12页
Background:In recent decades,the global incidence of dengue fever has been stead-ily increasing,with continuous geographical expansion.Researchers have successfully modeled most clinical symptoms of human dengue fever... Background:In recent decades,the global incidence of dengue fever has been stead-ily increasing,with continuous geographical expansion.Researchers have successfully modeled most clinical symptoms of human dengue fever using interferon type I(IFN-I)or combined IFN-I/II receptor knockout mice infected with dengue virus(DENV).However,this model requires further optimization to better support related studies.Methods:This study aimed to establish a stable dengue infection model by evaluating the effects of different genetic backgrounds and injection routes on DENV infection in interferon receptor knockout mice.We first infected various strains of interferon receptor-deficient mice with DENV and compared their susceptibility based on clini-cal symptoms,viremia levels,organ indices,histopathological findings,and vascular leakage markers.Subsequently,we selected the most susceptible strain to further investigate the impact of different injection methods on infection outcomes.Results:We found that BALB/c background mice with type 1 interferon recep-tor knockout(IFNAR)had the most obvious symptoms.Subsequently,we selected IFNAR−/−BALB/c mice to further explore the effects of different injection methods on dengue virus infection.The results showed that the intraperitoneal injection group had the most severe clinical symptoms,the longest duration of viremia,and the most obvious degree of organ damage.Conclusion:Through systematic screening and optimization,we established a robust animal model of dengue virus infection via intraperitoneal injection in IFNAR−/−BALB/c mice.This model offers a valuable tool for future dengue research. 展开更多
关键词 dengue fever IFNAR−/−BALB/c mice interferon receptor knockout mouse model
暂未订购
Short-lived Niemann-Pick type C mice with accelerated brain aging as a novel model for Alzheimer’s disease research
3
作者 Vikas Anil Gujjala Morteza Abyadeh +6 位作者 Isaiah Klimek Alexander Tyshkovskiy Naci Oz JoséPedro Castro Vadim N.Gladyshev Jason Newton Alaattin Kaya 《Neural Regeneration Research》 2026年第6期2531-2542,共12页
Alzheimer’s disease is initially thought to be caused by age-associated accumulation of plaques,in recent years,research has increasingly associated Alzheimer’s disease with lysosomal storage and metabolic disorders... Alzheimer’s disease is initially thought to be caused by age-associated accumulation of plaques,in recent years,research has increasingly associated Alzheimer’s disease with lysosomal storage and metabolic disorders,and the explanation of its pathogenesis has shifted from amyloid and tau accumulation to oxidative stress and impaired lipid and glucose metabolism aggravated by hypoxic conditions.However,the underlying mechanisms linking those cellular processes and conditions to disease progression have yet to be defined.Here,we applied a disease similarity approach to identify unknown molecular targets of Alzheimer’s disease by using transcriptomic data from congenital diseases known to increase Alzheimer’s disease risk,namely Down syndrome,Niemann-Pick type C disease,and mucopolysaccharidoses I.We uncovered common pathways,hub genes,and miRNAs across in vitro and in vivo models of these diseases as potential molecular targets for neuroprotection and amelioration of Alzheimer’s disease pathology,many of which have never been associated with Alzheimer’s disease.We then investigated common molecular alterations in brain samples from a Niemann-Pick type C disease mouse model by juxtaposing them with brain samples of both human and mouse models of Alzheimer’s disease.Detailed phenotypic,molecular,chronological,and biological aging analyses revealed that the Npc1tm(I1061T)Dso mouse model can serve as a potential short-lived in vivo model for brain aging and Alzheimer’s disease research.This research represents the first comprehensive approach to congenital disease association with neurodegeneration and a new perspective on Alzheimer’s disease research while highlighting shortcomings and lack of correlation in diverse in vitro models.Considering the lack of an Alzheimer’s disease mouse model that recapitulates the physiological hallmarks of brain aging,the short-lived Npc1^(tm(I1061T)Dso) mouse model can further accelerate the research in these fields and offer a unique model for understanding the molecular mechanisms of Alzheimer’s disease from a perspective of accelerated brain aging. 展开更多
关键词 aging biomarkers Alzheimer’s disease comparative genomics congenital diseases Down syndrome mouse model mucopolysaccharidoses I Niemann-Pick type c disease
暂未订购
知识图谱驱动的C++课程BOPPPS+ADCD教学模式探索 被引量:1
4
作者 王云艳 《计算机教育》 2026年第1期233-239,共7页
针对传统教学中自主学习和迁移学习不足、高阶计算思维培养不足、评价体系动态反馈不足等问题,提出知识图谱驱动的BOPPPS+ADCD线上线下混合教学模式,以C++程序设计课程为例,阐述如何通过知识图谱引领学生自主学习,并在BOPPPS参与式教学... 针对传统教学中自主学习和迁移学习不足、高阶计算思维培养不足、评价体系动态反馈不足等问题,提出知识图谱驱动的BOPPPS+ADCD线上线下混合教学模式,以C++程序设计课程为例,阐述如何通过知识图谱引领学生自主学习,并在BOPPPS参与式教学环节融入ADCD四阶段强化高阶计算思维训练,构建“教学—评价—改进”智慧评价的动态教学闭环以实现教学动态优化,最后说明教学实践效果。 展开更多
关键词 c++程序设计 知识图谱 BOPPPS+ADcD教学模式 智慧评价
在线阅读 下载PDF
基于KANO-FBS模型的抗阻训练产品模块化设计研究
5
作者 胡以萍 康馨予 《包装与设计》 2026年第1期30-32,共3页
目的 提升抗阻训练产品的场景适配能力,增强其模块组合的灵活性。方法 综合运用文献研究、实地调研等方法提取用户需求;基于KANO模型对用户需求进行分类并量化其优先级;借助FBS模型构建功能、行为、结构之间的关系,完成产品功能拆解与... 目的 提升抗阻训练产品的场景适配能力,增强其模块组合的灵活性。方法 综合运用文献研究、实地调研等方法提取用户需求;基于KANO模型对用户需求进行分类并量化其优先级;借助FBS模型构建功能、行为、结构之间的关系,完成产品功能拆解与模块划分;结合典型训练场景与用户特征,提出模块集成方案;最后提出模块接口设计原则与方法。结果 完成对抗阻训练产品模块化设计路径的探索。结论 本文可为抗阻训练产品模块设计提供一定的理论依据和方法参考。 展开更多
关键词 模块化设计 抗阻训练产品 KANO模型 fbs模型 用户需求
原文传递
基于等效应力的自冲铆C型框架疲劳寿命评估方法
6
作者 陈思韦 邢保英 +3 位作者 张洪申 张文韬 杨恒 曾凯 《兵器装备工程学报》 北大核心 2026年第2期10-16,共7页
C型框架是自冲铆接设备的主要承力部件,其在交变载荷作用下容易出现疲劳损伤失效。提出了基于危险点等效应力的疲劳寿命评估方法。对某型号自冲铆设备,开展C型框结构表面应力应变测试,明确结构危险点,同时,以冲压行程及冲压速度为影响... C型框架是自冲铆接设备的主要承力部件,其在交变载荷作用下容易出现疲劳损伤失效。提出了基于危险点等效应力的疲劳寿命评估方法。对某型号自冲铆设备,开展C型框结构表面应力应变测试,明确结构危险点,同时,以冲压行程及冲压速度为影响因素、危险点应力值为响应值,建立二者之间的回归模型,探究成形型工艺参数对结构危险点等效应力演变的影响规律。结果表明:C型框架结构危险点位于喉深顶部内侧,最大应力值为106.15 MPa,与仿真之间的误差为2.923%;冲压行程对框架危险部位应力值的影响最大,冲压速度次之;C型框架危险部位的疲劳寿命为3.46×10^(5)次,最小安全系数为0.832。本文提出的C型框结构疲劳寿命评估方法为铆接机承压部件的寿命预测及疲劳设计提供了一种新的思路。 展开更多
关键词 自冲铆 c型框架 疲劳寿命 回归模型 应变测试
在线阅读 下载PDF
Exploring the use of the 3C Model in the context of HPV vaccine hesitancy in women of childbearing age
7
作者 Nan Jiang Kui-Mei Zhang +4 位作者 Mei-Hua Wu Xiao-Lei Song Wei-Wei Sun Mei Wang Wen-Ming Cao 《Infectious Diseases Research》 2025年第1期16-27,共12页
Bacckground:Based on the 3C model,this study explores the current situation of HPV vaccine hesitancy among women of childbearing age and the factors influencing vaccine hesitancy.Methods:Based on the free cervical can... Bacckground:Based on the 3C model,this study explores the current situation of HPV vaccine hesitancy among women of childbearing age and the factors influencing vaccine hesitancy.Methods:Based on the free cervical cancer screening project in Baoan District,this study designed a questionnaire under the framework of vaccine hesitation 3C theory and carried out a self-filling electronic questionnaire survey among women of childbearing age.Results:The rate of HPV vaccination awareness among women of childbearing age in Bao’an District was 93.25%.HPV vaccine acceptance reached 71.55%,and 24.59%of the survey respondents experienced HPV vaccine hesitation,a high percentage of whom were hesitant.The influencing factors of HPV vaccine hesitation among women of childbearing age were perceived necessity of HPV vaccination(0.482),no one around them receiving the HPV vaccine(0.411),perception of the price of the vaccine(0.354),degree of trust in the safety of the vaccine(0.223),and degree of concern about the HPV vaccine(0.153).Conclusion:The 3C model can be used for the study of HPV vaccine hesitancy.Strengthening the publicity of HPV vaccination and improving women’s knowledge of the HPV vaccine can reduce their hesitation toward HPV vaccination. 展开更多
关键词 HPV vaccine vaccine hesitancy 3c model
暂未订购
Adapting High-Level Language Programming(C Language)Education in the Era of Large Language Models
8
作者 Baokai Zu Hongyuan Wang +1 位作者 Hongli Chen Yafang Li 《Journal of Contemporary Educational Research》 2025年第5期264-269,共6页
With the widespread application of large language models(LLMs)in natural language processing and code generation,traditional High-Level Language Programming courses are facing unprecedented challenges and opportunitie... With the widespread application of large language models(LLMs)in natural language processing and code generation,traditional High-Level Language Programming courses are facing unprecedented challenges and opportunities.As a core programming language for computer science majors,C language remains irreplaceable due to its foundational nature and engineering adaptability.This paper,based on the rapid development of large model technologies,proposes a systematic reform design for C language teaching,focusing on teaching objectives,content structure,teaching methods,and evaluation systems.The article suggests a teaching framework centered on“human-computer collaborative programming,”integrating prompt training,AI-assisted debugging,and code generation analysis,aiming to enhance students’problem modeling ability,programming expression skills,and AI collaboration literacy. 展开更多
关键词 Large language models(LLMs) High-level language programming c language Human-computer collaborative programming
在线阅读 下载PDF
Ta-C涂层刀具钻削Al-50wt%Si合金的钻削力预测模型研究
9
作者 邹继胤 金成哲 +1 位作者 周浩淳 刘玮 《工具技术》 北大核心 2026年第1期70-77,共8页
Al-50wt%Si合金具有低热膨胀系数、高硬度、优异耐磨性和轻量化特性,也因高硅铝含量导致其存在加工难题,通过物理气相沉积(PVD)技术在硬质合金麻花钻表面制备Ta-C涂层。采用正交试验和单因素试验法,对Al-50wt%Si合金进行钻削试验,探究... Al-50wt%Si合金具有低热膨胀系数、高硬度、优异耐磨性和轻量化特性,也因高硅铝含量导致其存在加工难题,通过物理气相沉积(PVD)技术在硬质合金麻花钻表面制备Ta-C涂层。采用正交试验和单因素试验法,对Al-50wt%Si合金进行钻削试验,探究钻头直径d、主轴转速n和进给量f对钻削力的影响规律。结果表明:Ta-C涂层凭借其高硬度和低摩擦系数,显著降低钻削轴向力和扭矩;轴向力与扭矩随钻头直径与进给量的增大呈线性增长,而随主轴转速升高呈现先降后增的趋势。通过多元线性回归分析,建立Ta-C涂层钻削力预测模型,其预测平均误差为4.85%,且方差分析表明模型具有高度显著性,为实现Al-50wt%Si合金的高效、低成本加工提供理论支撑与工艺优化参考。 展开更多
关键词 Ta-c涂层 Al-50wt%Si合金 钻削力 预测模型
在线阅读 下载PDF
A novel carcinogenic mouse model by site-directed insertion of tandem human HRAS large DNA fragment into 15E1 site
10
作者 Susu Liu Yanwei Yang +10 位作者 Guitao Huo Hao Yang Zhao Chen Ling YuYa Wang Shijie Zhai Xiaowei Sun Wenda Gu Yuan Cao Wei Gong Sanlong Wang Changfa Fan 《Animal Models and Experimental Medicine》 2025年第11期1983-1996,共14页
Background:The precise insertion of large DNA fragments(>3–5 kb)remains one of the key obstacles in establishment of genetically modified murine models.Methods:A 21 kb large DNA fragment containing three tandemly ... Background:The precise insertion of large DNA fragments(>3–5 kb)remains one of the key obstacles in establishment of genetically modified murine models.Methods:A 21 kb large DNA fragment containing three tandemly linked copies of the human HRAS gene was inserted into the genome of C57BL/6J mouse,generating a mouse model designated as KI.C57-ras(or named NF-h HRAS).Whole-genome sequencing and Sanger sequencing were utilized to it confirm precise insertion and copy number.The stability of transgene expression among different generations was verified from multiple aspects using by digital PCR,western blot and DNA sequencing.To assess tumor susceptibility in the mouse model,N-Nitroso-N-methylurea(MNU)was administered at a dosage of 75 mg/kg.Histopathological examinations were conducted using hematoxylin and eosin(H&E)staining.Results:The HRAS DNA fragment was inserted into mouse chromosome 15E1 site,locating between 80623202 bp and 80625020 bp.NF-h HRAS mice exhibited stable inheritance and displayed consistent phenotypes across individuals.Moreover,this mouse model exhibited a high susceptibility to carcinogens.Upon administration of MNU the earliest mortality onset was earlier than that of wild-type littermates(day 65 vs.day 78 for male and day 56 vs.day 84 for female).Notably,100%of the NF-h HRAS transgenic mice developed tumors,with approximately 84%of male NF-h HRAS mice exhibiting specific tumor types,such as squamous cell carcinoma or squamous cell papilloma,which was consistent with the previously reported carcinogenic rasH2 mouse model.The types of tumors and the target organs exhibited diversity in NFh HRAS mice,while the spontaneous tumor incidence remained low(1/50).Conclusions:The NF-h HRAS mice demonstrated excellent genetic stability,a reproducible phenotype,and high susceptibility to carcinogens,indicating their potential utility in non-clinical safety evaluations of drugs as per the S1B guidelines issued by the ICH(The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use). 展开更多
关键词 human HRAS gene IcH S1B guideline KI.c57-ras carcinogenic mouse model large DNA fragment editing non-clinical carcinogenicity evaluation
暂未订购
基于AHP-FBS-TRIZ的矿井避难硐室设计研究
11
作者 关凯元 孟宪宇 +2 位作者 耿林松 靳月鑫 白千 《煤炭工程》 北大核心 2026年第1期18-27,共10页
针对矿井突发事故应急避难需求,旨在设计一款具备快速响应、灵活部署能力的可移动式避难硐室。通过整合层次分析法(AHP)、功能—行为—结构模型(FBS)与发明问题解决理论(TRIZ),构建了一套系统化、创新驱动的设计方法。首先运用AHP识别... 针对矿井突发事故应急避难需求,旨在设计一款具备快速响应、灵活部署能力的可移动式避难硐室。通过整合层次分析法(AHP)、功能—行为—结构模型(FBS)与发明问题解决理论(TRIZ),构建了一套系统化、创新驱动的设计方法。首先运用AHP识别并量化矿工应急需求,确定关键功能指标;继而通过FBS模型实现从功能到结构的映射,明确设计路径;最后借助TRIZ工具解决设计矛盾,提升方案创新性与可靠性。基于该方法完成了避难硐室装置设计,并利用人机工效学分析软件Jack进行数字仿真验证。结果表明,所提出的AHP-FBS-TRIZ集成设计模式能有效引导设计重点,显著提升装置的设计效率与综合性能,为实现可靠、高效、快速的矿井应急避险提供了可行方案,对提高矿难救援效率具有实际意义。 展开更多
关键词 层次分析法 功能模型 发明问题解决理论 矿井避难硐室 装置设计
在线阅读 下载PDF
Environmental controls over calcium and magnesium concentrations in the forest floor and topsoil in the Loess Plateau,China
12
作者 Feng Xue Ning Pan +9 位作者 Hongkun Cui Aolin Li Mingfei Zhao Kaixiong Xing Yuhang Wang Xuejuan Bai Can Wang Zhijun Yu Jingze Liu Muyi Kang 《Journal of Forestry Research》 2026年第2期201-212,共12页
The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variabl... The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variables as well as their interactions remain unclear,especially in areas undergoing long-term forest restoration.In this study,Ca and Mg concentrations in the forest floor and topsoil from 239 forest plots across the Loess Plateau were measured,and the effects of forest types,climate,soil properties,stand characteristics and nitrogen deposition were explored.The results showed significantly higher Ca concentrations in the forest floor(20.68±8.04 mg/g)than in the topsoil(13.28±12.83 mg/g),whereas Mg exhibited the inverse pattern(3.64±1.09 and 10.11±2.51 mg/g,respectively).The effect of forest types was only significant on forest floor Ca,and Ca concentrations were higher in broadleaf and mixed forests than in coniferous forests.Overall,Ca and Mg concentrations in forest floor and topsoil increased with latitudes while decreased with elevations,and the significance of the trends varied among forest types.Forest floor Ca and Mg were mainly influenced by environmental variables aboveground,i.e.,basal area(BA)and mean annual precipitation(MAP),respectively;topsoil Ca and Mg were more affected by soil properties(soil C/N and pH,respectively).Those suggested a depletion of Ca belowground was associated with forest growth and enriched soil nitrogen,and the leaching of mobile Mg was correlated with rainfall and soil acidification.Besides,the impact of environmental variables on Ca-Mg balance(Ca/Mg ratio)belowground was primarily through the regulation of Ca.Elucidating the influence of environmental variables will improve our ability to predict future changes in base cations and thus forest soil health in the greening vegetated Loess Plateau. 展开更多
关键词 Soil c/N Basal area Random-forest model Temperate forests Base cations ELEVATION
在线阅读 下载PDF
KJ-KANO-FBS模型下人与宠物犬共用沙发的设计
13
作者 熊紫欣 钟世禄 《家具》 2026年第1期19-24,共6页
运用KJ、KANO与FBS三者相结合的创新方法,系统地解构饲养者与宠物犬在共居场景中的行为特征,旨在满足饲养者和宠物犬对于沙发使用的生理与心理方面的需求。运用KJ法将用户访谈、实地调查等得出的用户需求信息进行归类;设置问卷对用户进... 运用KJ、KANO与FBS三者相结合的创新方法,系统地解构饲养者与宠物犬在共居场景中的行为特征,旨在满足饲养者和宠物犬对于沙发使用的生理与心理方面的需求。运用KJ法将用户访谈、实地调查等得出的用户需求信息进行归类;设置问卷对用户进行调研,使用KANO模型将问卷结果进行属性分类、绘制Better-Worse系数图、计算用户需求权重,基于这些分析各需求的优先级;筛选KANO模型结果中非装饰性方面的需求进行功能-行为-结构之间的映射。验证了该框架模型在产品设计中的可实践性,进一步解决人宠共居场景下的行为交互痛点,提升用户需求满意度。 展开更多
关键词 人宠交互 KJ-KANO-fbs模型 家具设计 用户需求
在线阅读 下载PDF
基于血清SAA/CRP、RBP水平的难治性肺炎支原体肺炎患儿不良预后预测模型构建
14
作者 常甄瑱 高婉卿 +2 位作者 童仁香 陈倩 柳娜娜 《山东医药》 2026年第1期74-78,共5页
目的基于血清淀粉样蛋白A/C反应蛋白(SAA/CRP)、视黄醇结合蛋白(RBP)水平构建难治性肺炎支原体肺炎(RMPP)患儿不良预后的预测模型。方法选取收治的RMPP患儿198例,检测其血清SAA、CRP和RBP水平,并计算SAA/CRP,根据入院后28 d预后将RMPP... 目的基于血清淀粉样蛋白A/C反应蛋白(SAA/CRP)、视黄醇结合蛋白(RBP)水平构建难治性肺炎支原体肺炎(RMPP)患儿不良预后的预测模型。方法选取收治的RMPP患儿198例,检测其血清SAA、CRP和RBP水平,并计算SAA/CRP,根据入院后28 d预后将RMPP患儿分为不良预后和良好预后,并收集患儿相关临床资料。采用多因素Logistic回归分析不良预后的影响因素并构建预测模型,采用ROC曲线分析各指标及预测模型对RMPP患儿不良预后的预测价值,采用Bootstrap自助法进行内部验证。结果入院28 d后,198例RMPP患儿不良预后发生率为30.30%(60/198)。不良预后患儿较良好预后患儿重症比例高,热程和氧疗时间长,血清SAA/CRP高,RBP水平低(P均<0.05)。多因素回归分析显示,热程、重症RMPP、氧疗时间长、血清SAA/CRP高为RMPP患儿不良预后的独立危险因素,RBP水平高为独立保护因素(P均<0.05)。根据独立影响因素构建预测模型,回归方程为Logit(P)=-10.707+0.347×热程+1.811×病情程度+0.765×氧疗时间+1.085×SAA/CRP-0.258×RBP,曲线下面积为0.920,高于热程、病情程度、氧疗时间、SAA/CRP、RBP单独预测的0.674、0.696、0.682、0.755、0.747(P均<0.05)。Hosmer-Lemeshow检验显示χ^(2)=6.320,P=0.611,模型拟合良好。经1000次Bootstrap自助法进行内部验证,预测模型的C指数为0.920,区分度、稳定性较高。结论血清SAA/CRP水平升高和RBP水平降低与RMPP患儿不良预后相关,基于此构建的预测模型对其有较高的预测效能。 展开更多
关键词 难治性肺炎支原体肺炎 血清淀粉样蛋白A c反应蛋白 视黄醇结合蛋白 预测模型
暂未订购
自主学习视角下开放教育学习者在线学习行为意愿“进阶”之路——基于拓展“C-TAM-TPB”模型的实证研究
15
作者 沈志仁 李欣欣 《成人教育》 北大核心 2026年第2期48-60,共13页
在数字化和终身教育背景下,开放教育承载着培养自主学习型人才的重要使命。然而,当前部分开放教育学习者的在线学习行为仍具有较强的功利性,主要以完成学业要求为目标,缺乏深度学习和主动探索的意识。为促进学习者由被动接受走向自主学... 在数字化和终身教育背景下,开放教育承载着培养自主学习型人才的重要使命。然而,当前部分开放教育学习者的在线学习行为仍具有较强的功利性,主要以完成学业要求为目标,缺乏深度学习和主动探索的意识。为促进学习者由被动接受走向自主学习,基于拓展的“C-TAM-TPB”模型,以616名广西开放教育学习者为样本,依托PLS-SEM数据分析法,探讨影响开放教育学习者在线自主学习行为意愿的关键因素。实证分析结果表明,在线自主学习行为态度、自我调节学习能力与学校支持是影响在线自主学习行为意愿的直接因素,信息素养、感知有用性及主观规范通过间接路径发挥作用。研究结果有助于深化对开放教育学习者在线自主学习行为意愿机制的理解,并为提升开放教育质量与自主学习支持体系建设提供理论参考与实践启示。 展开更多
关键词 开放教育 自主学习 在线自主学习行为意愿 c-TAM-TPB模型
在线阅读 下载PDF
力-热-氧耦合下C/SiC复合材料失效机理与强度分析
16
作者 周松 刘烨 《强度与环境》 2026年第1期55-64,共10页
碳纤维增强陶瓷基复合材料(C/SiC)在高温含氧环境中易发生由氧化反应引起的碳纤维表面微观结构损伤,从而显著影响其力学性能与寿命。本文针对力-热-氧耦合环境下C/SiC复合材料的氧化失效行为开展了多尺度机理分析与性能预测;建立了碳纤... 碳纤维增强陶瓷基复合材料(C/SiC)在高温含氧环境中易发生由氧化反应引起的碳纤维表面微观结构损伤,从而显著影响其力学性能与寿命。本文针对力-热-氧耦合环境下C/SiC复合材料的氧化失效行为开展了多尺度机理分析与性能预测;建立了碳纤维单丝氧化失效模型、SiC包覆碳纤维单丝的力学性能预测模型;并对C/SiC平纹编织复合材料在不同温度(500℃、800℃及1400℃)和氧分压21kPa条件下的拉伸强度进行了预测。研究表明,在上述条件下,碳纤维失重仿真模拟与已有文献比较,误差不超过10%;而C/SiC平纹编织复合材料氧化后的拉伸强度预测值与试验结果相比最大误差为29.1%。本文开发的模型和方法为在同时受到载荷、高温和氧气环境影响的真实条件下复合材料的性能评估与寿命预测提供了理论支持。 展开更多
关键词 c/SIc复合材料 氧化失效 多尺度模拟 性能预测
在线阅读 下载PDF
C形金属环密封特性及其结构优化研究
17
作者 白鹏巨 魏文澜 +3 位作者 章娅菲 李玉强 姚磊 刘森 《机电工程技术》 2026年第4期27-33,共7页
井下高温安全阀的密封性能取决于其关键部件金属C形密封环的力学特性,其结构参数对其密封有显著影响。研究了C形密封环内外径匹配变化的条件下对内外密封接触应力的影响规律,并基于此建立了密封环的结构参数优化模型。为了克服传统研究... 井下高温安全阀的密封性能取决于其关键部件金属C形密封环的力学特性,其结构参数对其密封有显著影响。研究了C形密封环内外径匹配变化的条件下对内外密封接触应力的影响规律,并基于此建立了密封环的结构参数优化模型。为了克服传统研究中单因素分析与手动建模的局限性,构建了一套基于Python与SolidWorks-ANSYS的自动化联合仿真模型,对可变结构参数的开展了高通量分析,基于120组全因子试验的有限元分析结果,研究揭示了内外径对双侧接触应力及应力差的耦合作用机制,并据此建立了活塞杆侧接触应力与活塞套侧接触应力的应力预测模型,进一步通过引入应力均衡约束,确定了实现双侧应力最优均衡的内外径参数组合准则,并给出了平衡接触应力的经验公式。 展开更多
关键词 c形密封环 有限元分析 参数优化 优化模型
在线阅读 下载PDF
MELD评分联合血清胱抑素C和ALBI评分诊断失代偿期肝硬化患者并发肝肾综合征价值研究
18
作者 孙博汉 曹春莉 奇丽娜 《实用肝脏病杂志》 2026年第2期249-252,共4页
目的探讨终末期肝病模型(MELD)评分、白蛋白-胆红素(ALBI)评分和血清胱抑素C(Cys-C)联合预测失代偿期肝硬化并发肝肾综合征-急性肾损伤(HRS-AKI)的价值。方法2020年10月~2025年4月我院收治的HRSAKI患者99例和失代偿肝硬化住院患者117例... 目的探讨终末期肝病模型(MELD)评分、白蛋白-胆红素(ALBI)评分和血清胱抑素C(Cys-C)联合预测失代偿期肝硬化并发肝肾综合征-急性肾损伤(HRS-AKI)的价值。方法2020年10月~2025年4月我院收治的HRSAKI患者99例和失代偿肝硬化住院患者117例,应用医院信息管理(HIS)系统收集临床基线资料、血生化指标和血清Cys-C水平,计算MELD和ALBI评分。应用二元Logistic回归分析影响并发HRS-AKI的因素,应用受试者工作特征曲线(ROC)评估各指标对HRS-AKI的诊断效能。结果99例住院期间发生HRS-AKI患者血清Cys-C水平、MELD评分和ALBI评分分别为2.4(1.6,3.3)mg/L、19.9(11.8,24.3)和-1.1(-1.5,-0.6),均显著高于肝硬化组【分别为1.1(0.9,1.4)mg/L、10.9(7.4,14.5)和-1.4(-1.5,-0.9),P<0.05】;Logistic回归分析显示,凝血酶原时间是影响肝硬化患者并发HRS-AKI的保护因素(OR=0.852,95%CI=0.752~0.964,P<0.05),而血清Cys-C(OR=42.318,95%CI=13.179~135.888,P<0.001)、MELD评分(OR=25.539,95%CI=4.266~152.892,P<0.001)和并发肝性脑病(OR=4.527,95%CI=1.283~15.969,P<0.05)是独立危险因素;ROC分析显示,血清Cys-C联合MELD评分和ALBI评分诊断HRS-AKI的AUC为0.918(95%CI:0.877~0.959),其效能较高。结论监测血清Cys-C水平联合MELD评分和ALBI评分可以帮助临床医师更加明确诊断住院的失代偿肝硬化患者并发HRS-AKI,值得进一步研究。 展开更多
关键词 肝硬化 肝肾综合征 胱抑素c 终末期肝病模型 白蛋白-胆红素评分 诊断
暂未订购
丹参酮ⅡA与灯盏乙素协同抑制PKCδ/NLRC4/Caspase-1通路改善缺血性脑卒中的机制
19
作者 颜雨暄 岳姣 +10 位作者 姜永莉 胡丽宁 靳雨晨 贺然 卢玉洁 鲁贝宁 郭青娟 刘晨旭 刘子璇 王欣赏 刘水冰 《空军军医大学学报》 2026年第2期273-283,共11页
目的探究丹参酮ⅡA(TanⅡA)与灯盏乙素(Scu)对缺血性脑卒中的协同神经保护作用及潜在分子机制。方法体外培养原代神经元,建立谷氨酸(Glu)诱导的兴奋性毒性损伤模型,初步筛选具有神经保护作用的中药单体,并利用H_(2)O_(2)诱导的氧化应激... 目的探究丹参酮ⅡA(TanⅡA)与灯盏乙素(Scu)对缺血性脑卒中的协同神经保护作用及潜在分子机制。方法体外培养原代神经元,建立谷氨酸(Glu)诱导的兴奋性毒性损伤模型,初步筛选具有神经保护作用的中药单体,并利用H_(2)O_(2)诱导的氧化应激损伤模型进行验证。构建光化学血栓卒中(PTS)小鼠模型,探究TanⅡA和Scu的协同体内保护作用。采用神经功能缺损评分、TTC染色、HE染色和尼氏染色评估神经功能与组织损伤,利用RNA测序、Western blotting、ELISA及qRT-PCR技术探索分子机制。结果体外实验中,TanⅡA或Scu均能显著改善Glu或H_(2)O_(2)引起的神经元损伤。体内实验中,TanⅡA与Scu联合给药可显著降低PTS模型小鼠的神经功能缺损评分、缩小梗死体积并减轻神经元损伤,且效果优于任一单药。RNA测序分析显示,联合给药能显著下调Prkcd基因表达;分子生物学检测证实,联合治疗可协同抑制PKCδ/NLRC4/Caspase-1信号通路,降低IL-1β、IL-18等促炎因子水平,减轻神经炎症反应。结论TanⅡA和Scu通过抑制PKCδ/NLRC4/Caspase-1信号通路介导的神经炎症,发挥协同神经保护作用,为缺血性脑卒中的治疗提供了新策略。 展开更多
关键词 缺血性卒中 丹参酮ⅡA 黄酮类 神经保护 神经炎性疾病 蛋白激酶cδ 半胱天冬酶1 疾病模型 动物
暂未订购
大禹节水基于“C+F+EPC+O”模式的战略演进与价值重构研究
20
作者 郭龙 《价值工程》 2026年第6期67-70,共4页
本研究以商业模式演进理论为基础,聚焦大禹节水集团股份有限公司从传统节水设备制造商向“三农三水”综合服务商的战略转型过程,系统剖析其“C+F+EPC+O”(咨询+融资+设计采购施工+运营)商业模式的构建与实践路径。通过解析“元谋模式”... 本研究以商业模式演进理论为基础,聚焦大禹节水集团股份有限公司从传统节水设备制造商向“三农三水”综合服务商的战略转型过程,系统剖析其“C+F+EPC+O”(咨询+融资+设计采购施工+运营)商业模式的构建与实践路径。通过解析“元谋模式”“武清模式”等典型案例,揭示了企业从“交付产品”到“投资价值”的战略演进逻辑,以及在此过程中实现的价值主张、价值创造方式和价值获取机制的三维系统性重构。研究发现,该模式推动大禹节水完成了从“工程承包商”向“产业合伙人”的角色跃迁,并通过数字技术赋能与生态协同,形成了可持续的综合服务能力。本文不仅从理论层面丰富了工程企业转型与价值重构的研究视角,也为同类企业向高质量综合服务商转型提供了可借鉴的实践框架与实施路径。 展开更多
关键词 c+F+EPc+O 战略演进 价值重构 大禹节水 商业模式创新 投融建营一体化
在线阅读 下载PDF
上一页 1 2 196 下一页 到第
使用帮助 返回顶部