期刊文献+
共找到1,035,778篇文章
< 1 2 250 >
每页显示 20 50 100
衡水市中小食品企业质量管理实践研究——基于PLS-SEM模型的实证分析
1
作者 朱冰清 王岩 +2 位作者 吴荣荣 王青华 张跃 《衡水学院学报》 2026年第1期60-69,共10页
随着食品质量与安全在全球范围内日益受到重视,中小食品企业面临着提高自身运营绩效和产品质量的双重挑战。研究旨在探究衡水市中小食品企业质量管理实践的关键成功因素,以及这些因素对企业运营绩效的影响。通过结构方程模型和偏最小二... 随着食品质量与安全在全球范围内日益受到重视,中小食品企业面临着提高自身运营绩效和产品质量的双重挑战。研究旨在探究衡水市中小食品企业质量管理实践的关键成功因素,以及这些因素对企业运营绩效的影响。通过结构方程模型和偏最小二乘算法(PLS-SEM)分析相关数据,研究重点关注了六个主要维度,分别为领导力、教育与培训、员工参与、客户导向、过程管理和供应商管理。结果表明,这些因素对提升中小食品企业的运营绩效具有显著的正面影响。 展开更多
关键词 质量管理 成功因素 中小食品企业 运营绩效 pls-SEM分析
在线阅读 下载PDF
Crystal structure,thermal analysis,and luminescence properties of six heterocyclic lanthanide complexes
2
作者 SONG Zihe ZHAO Jinjin +1 位作者 REN Ning ZHANG Jianjun 《无机化学学报》 北大核心 2026年第1期181-192,共12页
Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'... Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6. 展开更多
关键词 lanthanide complexes fluorescence property crystal structure thermal analysis
在线阅读 下载PDF
Changes in border-associated macrophages after stroke: Single-cell sequencing analysis 被引量:1
3
作者 Ning Yu Yang Zhao +3 位作者 Peng Wang Fuqiang Zhang Cuili Wen Shilei Wang 《Neural Regeneration Research》 2026年第1期346-356,共11页
Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macro... Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macrophages have been poorly understood and largely overlooked. However, a recent study reported that border-associated macrophages participate in stroke-induced inflammation, although many details and the underlying mechanisms remain unclear. In this study, we performed a comprehensive single-cell analysis of mouse border-associated macrophages using sequencing data obtained from the Gene Expression Omnibus(GEO) database(GSE174574 and GSE225948). Differentially expressed genes were identified, and enrichment analysis was performed to identify the transcription profile of border-associated macrophages. CellChat analysis was conducted to determine the cell communication network of border-associated macrophages. Transcription factors were predicted using the ‘pySCENIC' tool. We found that, in response to hypoxia, borderassociated macrophages underwent dynamic transcriptional changes and participated in the regulation of inflammatory-related pathways. Notably, the tumor necrosis factor pathway was activated by border-associated macrophages following ischemic stroke. The pySCENIC analysis indicated that the activity of signal transducer and activator of transcription 3(Stat3) was obviously upregulated in stroke, suggesting that Stat3 inhibition may be a promising strategy for treating border-associated macrophages-induced neuroinflammation. Finally, we constructed an animal model to investigate the effects of border-associated macrophages depletion following a stroke. Treatment with liposomes containing clodronate significantly reduced infarct volume in the animals and improved neurological scores compared with untreated animals. Taken together, our results demonstrate comprehensive changes in border-associated macrophages following a stroke, providing a theoretical basis for targeting border-associated macrophages-induced neuroinflammation in stroke treatment. 展开更多
关键词 border-associated macrophages CLODRONATE hypoxia ISCHEMIA-REPERFUSION ischemic stroke liposomes neuroinflammation single-cell sequencing analysis STAT3 tumor necrosis factor
暂未订购
Comprehensive pan-cancer analysis of the receptor-interacting protein kinase family expression,genomic alterations,and functional implications
4
作者 Wan-Rong Li Xin Li Jian Wang 《Life Research》 2026年第1期35-44,共10页
Background:Receptor-interacting protein kinases(RIPKs)regulate cell death,inflammation,and immune responses,yet their roles in cancer are not fully understood.This study investigates the expression,genomic alterations... Background:Receptor-interacting protein kinases(RIPKs)regulate cell death,inflammation,and immune responses,yet their roles in cancer are not fully understood.This study investigates the expression,genomic alterations,and functional implications of RIPK family members across various cancers.Methods:We collected multi-omics data from The Cancer Genome Atlas and other public databases,including gene expression,copy number variation(CNV),mutation,methylation,tumor mutation burden(TMB),and microsatellite instability(MSI).Differential expression and survival analyses were performed using DESeq2 and Cox proportional hazards models.CNV and mutation data were analyzed with GISTIC2 and Mutect2,and methylation data with the ChAMP package.Correlations with TMB and MSI were assessed using Pearson coefficients,and gene set enrichment analysis was conducted with the MSigDB Hallmark gene sets.Results:RIPK family members show significant differential expression in various cancers,with RIPK1 and RIPK4 frequently altered.Survival analysis reveals heterogeneous impacts on overall survival.CNV and mutation analyses identify high alteration frequencies for RIPK2 and RIPK7,affecting gene expression.RIPK1 and RIPK7 are hypermethylated in several cancers,inversely correlating with RIPK3 expression.RIPK1,RIPK2,RIPK5,RIPK6,and RIPK7 correlate positively with TMB,while RIPK3 shows negative correlations in some cancers.MSI analysis indicates associations with DNA mismatch repair.G ene set enrichment analysis highlights immune-related pathway enrichment for RIPK1,RIPK2,RIPK3,and RIPK6,and cell proliferation and DNA repair pathways for RIPK4 and RIPK5.RIPK family members showed heterogeneous alterations across cancers:for example,RIPK7 was mutated in up to~15%of u terine c orpus e ndometrial c arcinoma and l ung s quamous c ell c arcinoma cases,and RIPK1 and RIPK7 exhibited frequent promoter hypermethylation in multiple tumor types.Several genes displayed context-dependent associations with overall survival and with TMB/MSI.Conclusion:This pan-cancer analysis of the RIPK family reveals their diverse roles and potential as biomarkers and therapeutic targets.The findings emphasize the importance of RIPK genes in tumorigenesis and suggest context-dependent functions across cancer types.Further studies are needed to explore their mechanisms in cancer development and clinical applications. 展开更多
关键词 RIPK family pan-cancer analysis tumor mutation burden microsatellite instability gene set enrichment analysis
暂未订购
Advanced isoconversional kinetic analysis of lepidolite sulfation product decomposition reactions for selectively extracting lithium
5
作者 Yubo Liu Baozhong Ma +4 位作者 Jiahui Cheng Xiang Li Hui Yang Chengyan Wang Yongqiang Chen 《International Journal of Minerals,Metallurgy and Materials》 2026年第1期217-227,共11页
The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.A... The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium. 展开更多
关键词 LITHIUM LEPIDOLITE decomposition reactions KINETICS isoconversional analysis
在线阅读 下载PDF
Global research status in the treatment of glaucoma:a systematic bibliometric analysis
6
作者 Wen-Hui Liu Chang Shu +1 位作者 Bei-Di Jia Xiao-Rong Li 《International Journal of Ophthalmology(English edition)》 2026年第2期379-392,共14页
AIM:To present an overview of the research on global glaucoma treatment in the last decade in terms of publication year,journals,countries/regions,organizations,references,and keywords,to investigate the current resea... AIM:To present an overview of the research on global glaucoma treatment in the last decade in terms of publication year,journals,countries/regions,organizations,references,and keywords,to investigate the current research international trends and hot topics in this area.METHODS:Bibliometric analysis was conducted on 9128 articles in the Web of Science Core Collection(WoSCC;Clarivate)database.Quantitative and qualitative analysis was employed using VOSviewer(v1.6.18),Pajek(v1.0.0.0),and CiteSpace(v6.1.R2)software.RESULTS:The 9128 papers relating to glaucoma treatment were published from April 2013 to April 2023,of which 7482 articles(82%)were original research articles and 1464(18%)were review articles.The United States(2867)and Johns Hopkins University(166)were the most productive country and institution,respectively,but the University College London had the highest h-index(54).The Journal of Glaucoma was the most productive and Ophthalmology had the highest h-index compared with other journals.The Keywords of interest included treatment surgery,cyclophotocoagulation,minimally invasive glaucoma surgery(MIGS),trabeculectomy,baerveldt,epidemiology,medication adherence,nanoparticle,optical coherence tomography(OCT),gene therapy,and artificial intelligence(AI).Glaucoma surgery appeared as a current research hotspot through the analysis of keywords.CONCLUSION:This study provides insights into the research trends and potential research hotspots in the treatment of glaucoma.This will help researchers to evaluate research policies and to promote international cooperation. 展开更多
关键词 glaucoma treatment bibliometric analysis SURGERY minimally invasive glaucoma surgery NANOPARTICLE
原文传递
Combined Fault Tree Analysis and Bayesian Network for Reliability Assessment of Marine Internal Combustion Engine
7
作者 Ivana Jovanović Çağlar Karatuğ +1 位作者 Maja Perčić Nikola Vladimir 《哈尔滨工程大学学报(英文版)》 2026年第1期239-258,共20页
This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for ... This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels. 展开更多
关键词 Fault tree analysis Bayesian network RELIABILITY REDUNDANCY Internal combustion engine
在线阅读 下载PDF
Sensitivity analysis of rod rearrangement in criticality safety for PWR fuel assemblies under transportation accidents
8
作者 Xin‑Ling Dai De‑Chang Cai +1 位作者 Yan‑Min Zhang Jin Cai 《Nuclear Science and Techniques》 2026年第1期263-282,共20页
To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains i... To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains in a subcritical state during routine,normal,and accidental transport conditions.In the event of an accident,the rods within the storage tank may become rearranged,introducing uncertainty that must be accounted for to ensure that criticality analysis results are conservative.Historically,this uncertainty was addressed overly conservatively due to limited research on non-uniform arrangement scenarios,which proved unsuitable for criticality safety analysis of spent fuel packages.This paper introduced three distinct methods to non-uniformly rearrange fuel rods—Uniform Arrangement by Blocks,Layer-by-Layer Determination,and Birdcage Deformation—and meticulously evaluates the influences of rod rearrangement on the effective multiplication factor of neutrons,k eff,utilizing the Monte Carlo method.Ultimately,this study presents a holistic method capable of encompassing the entire spectrum of potential effects stemming from the rearrangement of fuel rods during rods mispositioning accident.By augmenting the safety margin,this approach proves to be adeptly suited for the criticality safety analysis of nuclear fuel transport containers. 展开更多
关键词 Criticality safety analysis Fuel transports Rods mispositioning accident Non-uniform arrangement
在线阅读 下载PDF
Heavy metal risks and policy analysis on using industrial waste salts for making value-added snow-melting agents
9
作者 Yubiao Ma Jiaxin Yin +2 位作者 Yunfei Wang Lei Wang Jianxin Zhu 《Journal of Environmental Sciences》 2026年第1期756-766,共11页
Industrial waste salts are commonly used to make value-added snow-melting agents to ensure traffic safety in northern China during winter and spring after snowfall.However,heavy metals in industrial waste salts may po... Industrial waste salts are commonly used to make value-added snow-melting agents to ensure traffic safety in northern China during winter and spring after snowfall.However,heavy metals in industrial waste salts may pose certain environmental risks.Snow-melting agents and snow samples were collected and analyzed from highways,arterial roads,footbridges,and other locations in Beijing after the snowstorm in December 2023.It was found that the main component of snow-melting agents was sodium chloride with high concentrations of Cu,Mn,and Zn,which are not regulated in the current policies,despite the recent promotion of environmentally friendly snow-melting agents.The Pb,Zn and Cr contents of some snow samples exceeded the limitation value of surface water quality standards,potentially affecting the soil and water environment near roadsides,although the snow-melting agents comply with relevant standards,which indicates the policy gap in the management of recycled industrial salts.We reviewed and analyzed the relevant standards for snow-melting agents and industrial waste salts proposed nationally and internationally over the past 30 years.Through comparative analysis,we proposed relevant policy recommendations to the existing quality standards of snow-melting agents and the management regulations of industrial waste salts,and the formulation of corresponding usage strategies,aimed at reducing the potential environmental release of heavy metals from the use of snow-melting agents,thereby promoting more sustainable green urban development and environmentally sound waste management. 展开更多
关键词 Snow-melting agent Heavy metals Industrial waste salts recycled Comparative analysis
原文传递
Evaluation of the protective effects of Crocus sativus L.against cypermethrin induced reproductive toxicity in male rats through the Nrf2 pathway and in silico ADMET analysis
10
作者 Fareena Tariq Farah Ijaz +9 位作者 Yasameen Hameed Jasim Farah Naz Channa Sohail Ahmed Ahmed Shandookh Hameed Sobia Alyas Ahmed Raheem Rayshan Tahira Bibi Nazima Yousaf Khan Sadia Bibi Jameel Ahmed Buzdar 《Traditional Medicine Research》 2026年第3期12-25,共14页
Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to i... Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice. 展开更多
关键词 Crocus sativus L. CYPERMETHRIN male reproductive toxicity Nrf2 pathway in silico ADMET analysis
暂未订购
我国专业学位研究生教育协同育人影响因素分析——基于PLS-SEM模型 被引量:3
11
作者 张丽华 宁梦妍 王一然 《教育理论与实践》 北大核心 2025年第3期19-23,共5页
专业学位研究生教育是培养高层次应用型人才的重要途径。全面深化协同育人机制是促进专业学位研究生教育从有质量地发展到高质量发展的关键点和突破口。从高校、企业、政府三个利益相关主体出发,通过PLS-SEM模型分析我国专业学位研究生... 专业学位研究生教育是培养高层次应用型人才的重要途径。全面深化协同育人机制是促进专业学位研究生教育从有质量地发展到高质量发展的关键点和突破口。从高校、企业、政府三个利益相关主体出发,通过PLS-SEM模型分析我国专业学位研究生教育协同育人影响因素的研究结果表明:高等学校发表科技成果、政府对境内企业R&D支出以及企业科研人员占比对协同育人产生显著影响。为了更好地促进我国专业学位研究生教育协同育人的发展,应建立高校赋能新质生产力的协同育人机制、多主体共建数字化协同育人平台并发挥资源集聚效应提升协同育人成效。 展开更多
关键词 专业学位研究生教育 协同育人 pls-SEM模型 高校 企业 政府
在线阅读 下载PDF
基于PLS-SEM的渭河流域径流演变效应解耦
12
作者 江善虎 江宏 +2 位作者 朱永卫 崔豪 任立良 《水资源保护》 北大核心 2025年第5期223-230,共8页
为定量解耦气候变化、人类活动与植被动态等多因素对流域水循环演变的影响,构建了渭河流域水循环多要素影响解耦框架;利用偏最小二乘结构方程模型(PLS-SEM)、Pearson相关分析与趋势分析法,解耦了1982—2020年渭河流域气候变化、人类活... 为定量解耦气候变化、人类活动与植被动态等多因素对流域水循环演变的影响,构建了渭河流域水循环多要素影响解耦框架;利用偏最小二乘结构方程模型(PLS-SEM)、Pearson相关分析与趋势分析法,解耦了1982—2020年渭河流域气候变化、人类活动、植被动态对渭河流域径流变化的直接和间接效应。结果表明:1982—2001年渭河流域气候变化与人类活动对径流影响的综合效应呈现均衡态势,气候变化和人类活动对径流的综合效应值分别为0.313、-0.315;2002—2020年人类活动的综合效应值(-0.667)显著超越气候变化(0.319),成为流域径流演变的主导驱动因素;1982—2001年径流减少的机制特征为降水主导、多因子协同,降水减少的直接效应与气温升高、植被恢复及人类活动的综合效应共同主导径流衰减过程;2002—2020年径流增加的机制特征为降水主控、工程消减,降水显著增加是导致径流增加的主导因素,而工程调控的直接效应抑制了径流增加的趋势,导致径流仅呈现微弱的恢复态势。 展开更多
关键词 气候变化 人类活动 植被动态 径流演变 pls-SEM 渭河流域
在线阅读 下载PDF
Improvement of quantitative analysis of molybdenum element using PLS-based approaches for laser-induced breakdown spectroscopy in various pressure environments 被引量:3
13
作者 Jiamin LIU Ding WU +4 位作者 Cailong FU Ran HAI Xiao YU Liying SUN Hongbin DING 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第3期140-147,共8页
An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normaliza... An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normalization methods with the partial least squares(PLS) method are developed for quantitative analysis of molybdenum(Mo) element in the multi-component alloy,which is the first wall material in the Experimental Advanced Superconducting Tokamak. In this study, the different spectral normalization methods(total spectral area normalization,background normalization, and reference line normalization) are investigated for reducing the uncertainty and improving the accuracy of spectral measurement. The results indicates that the approach of PLS based on inter-element interference is significantly better than the conventional PLS methods as well as the univariate linear methods in the various pressure for molybdenum element analysis. 展开更多
关键词 laser induced BREAKDOWN spectroscopy MOLYBDENUM VACUUM NORMALIZATION partial least SQUARES method quantitative analysis
在线阅读 下载PDF
创业学习对大学生创业意愿的影响机制研究——基于PLS-SEM模型的分析
14
作者 徐园园 《安徽职业技术学院学报》 2025年第1期89-96,共8页
创业意愿是潜在创业者是否付诸实际创业行动的关键决定因素,在创业研究领域备受关注。本研究基于社会认知理论,选取安徽省500名大学生作为调查样本,采用问卷调查法收集数据,借助统计分析软件,运用结构方程模型(SEM)探究创业学习对创业... 创业意愿是潜在创业者是否付诸实际创业行动的关键决定因素,在创业研究领域备受关注。本研究基于社会认知理论,选取安徽省500名大学生作为调查样本,采用问卷调查法收集数据,借助统计分析软件,运用结构方程模型(SEM)探究创业学习对创业意愿的内在作用机制。研究结果显示,创业学习对创业意愿及创业自我效能感均有显著正向影响;创业自我效能感对创业意愿有显著正向作用,且在创业学习与创业意愿间起部分中介效应。基于研究结论,本文提出了相应的对策建议。 展开更多
关键词 创业学习 创业意愿 创业自我效能感 pls-SEM模型
在线阅读 下载PDF
XRD结合PLS测定复合含能材料中CL-20的晶型含量
15
作者 周利园 王德祥 +3 位作者 张天龙 刘国权 李华 汤宏胜 《火炸药学报》 北大核心 2025年第8期756-762,I0003,共8页
为了解决复合含能材料中CL-20晶型定量分析问题,提出了一种基于X射线衍射(XRD)结合偏最小二乘(PLS)的定量分析方法;制备了不同晶型CL-20与DA基药混合的复合含能材料样品,采集了XRD谱图,并结合多种数据预处理(MSC、SNV、D1st、D2nd、WT)... 为了解决复合含能材料中CL-20晶型定量分析问题,提出了一种基于X射线衍射(XRD)结合偏最小二乘(PLS)的定量分析方法;制备了不同晶型CL-20与DA基药混合的复合含能材料样品,采集了XRD谱图,并结合多种数据预处理(MSC、SNV、D1st、D2nd、WT)和变量选择方法(SIPLS、BIPLS、CARS)对模型性能进行优化。结果表明,MSC-CARS-PLS模型对ε-CL-20和CL-20总含量的预测性能最优,其决定系数(R_(p)^(2))分别为0.9862和0.9759,对应的均方根误差(RMSE_(p))分别为0.5901和0.5276;将该模型应用于实际生产的复合含能材料样品中,预测结果与参考值高度一致,验证了其在CL-20晶型定量分析中的准确性与实用性;说明此方法是一种快速、准确的CL-20晶型定量分析方法。 展开更多
关键词 分析化学 偏最小二乘 pls X射线衍射 定量分析 CL-20 变量选择
在线阅读 下载PDF
基于KECA-PLS的风电机组健康状态评估 被引量:1
16
作者 马亮 任超 +1 位作者 刘月文 郝增孝 《计算机测量与控制》 2025年第5期351-360,共10页
针对风电机组整机性能退化趋势的及时准确预测需求,提出了一种结合核熵主成分分析与偏最小二乘法(KECA-PLS)的健康评估算法;该研究采用前置局部异常因子算法(LOF)对数据预处理,并通过高斯混合模型(GMM)对风电场数据集进行分类聚类,分类... 针对风电机组整机性能退化趋势的及时准确预测需求,提出了一种结合核熵主成分分析与偏最小二乘法(KECA-PLS)的健康评估算法;该研究采用前置局部异常因子算法(LOF)对数据预处理,并通过高斯混合模型(GMM)对风电场数据集进行分类聚类,分类标签指导后续分析;利用核熵成分分析(KECA)对数据实施降维处理并提取关键特征,结合SPE统计量监控风电机组运行状态;考虑到SCADA数据的非平稳与非线性特性,将PLS算法融入核熵框架以进行故障预测,依据预测残差动态设定报警阈值,确保故障的早期警示;算法应用模糊评判机制并生成风电机组退化状态的雷达图,直观展示了故障演进态势;该算法在某风电场的实际运营数据上的实施验证,证明了其有效评估风电机组即时健康状况的能力,以及清晰展示故障演变过程的可视化效果。 展开更多
关键词 偏最小二乘法(pls) 状态监测 健康评估 风电机组 可视化
在线阅读 下载PDF
Simulation Analysis of NAPLs Movement in the Subsurface Environment 被引量:1
17
作者 Zhao Yongsheng (Changchun University of Science & Technology,Changchun,130026,China) Wang Baichang (Daqing Petroleum Administrative Bureau,Daqing,163412,China) 《Global Geology》 1999年第1期95-103,共9页
Non aqueous phase liquids (NAPLs) pollution are worldwide problems at present. NAPLs which enter the underground through spills or leaks may cause long lasting soil and groundwater contamination problems. Groundwater ... Non aqueous phase liquids (NAPLs) pollution are worldwide problems at present. NAPLs which enter the underground through spills or leaks may cause long lasting soil and groundwater contamination problems. Groundwater can be contaminated by non aqueous phase contaminants that are less dense (LNAPL) or denser (DNAPL) than water. The movement of both types of NAPLs will be influenced by the hydrogeological conditions, such as groundwater level, hydraulic conductivity, and porosity etc., however, LNAPL pollutants tend to concentrate at the water table while DNAPL may migrate further down. Understanding the underground migration mechanisms of NAPLs is of primary importance in pollution prediction and site remediation. Several laboratory simulations for NAPLs’ underground movements in porous media have been done in the past (A.S.Abdul et al., 1988, 1989; C.Tang et al., 1995). In this paper, we try to use STOMP (Subsurface Transport Over Multiple Phases) code to simulate the underground migration of NAPLs. The main purposes are: (1). to understand NAPLs’ underground migration mechanisms; (2). to analyze the sensitivities of model parameters, such as hydraulic conductivity, porosity, etc., and to know what are the most sensitive and important parameters in the model application; and (3). to study NAPLs movements in different hydrogeological conditions. The simulations include: Through the computer simulation, we have found that hydraulic conductivity and porosity are very sensitive in the model simulation, small changes of these parameters will cause big difference of the results, therefore, it is essential to accurately determine these parameters for high quality model simulation; The movements of NAPLs in different geological formation are quite different, two different geological media ( clayey sand and sand ) have been chosen in this paper to simulate NAPLs movement with different combinations ( i.e., moving from clayey sand to sand, and from sand to clayey sand ), the results have been analyzed and discussed; Finally, the influence of groundwater level variation to NAPLs (LNAPL and DNAPL) movement has been simulated by using pumping and injecting wells in the model. The results are compared with laboratory simulations conducted by C.Tang et al.. These results may helpful to understand the behavior of NAPLs during the remediation, such as pumping and treat, and air sparging. It is also important to the design of the remediation plans. 展开更多
关键词 NApls POLLUTION model SIMULATION sensitivity analysis SUBSURFACE ENVIRONMENT
在线阅读 下载PDF
教师数字化教学能力影响因素实证研究——基于PLS-SEM和fsQCA方法 被引量:11
18
作者 周欣 王耀斌 贺相春 《现代教育技术》 2025年第3期66-76,共11页
数字化教学能力是教育数字化转型时期教师必备的关键能力,深入探究并分析教师数字化教学能力的影响因素,是教育管理者和教师应对技术挑战、提升教学质量、培养创新人才的关键环节。基于此,文章依托统一接受和使用技术(Unified Theory of... 数字化教学能力是教育数字化转型时期教师必备的关键能力,深入探究并分析教师数字化教学能力的影响因素,是教育管理者和教师应对技术挑战、提升教学质量、培养创新人才的关键环节。基于此,文章依托统一接受和使用技术(Unified Theory of Acceptance and Use of Technology,UTAUT)模型,采用偏最小二乘结构方程模型(Partial Least Squares Structural Equation Modeling,PLS-SEM)和模糊集定性比较分析(Fuzzy-Set Qualitative Comparative Analysis,fsQCA)方法,对教师数字化教学能力的影响因素及其组合效应进行了实证分析。其中,PLS-SEM分析结果表明,绩效期望、努力期望、社群影响、便利条件和自我效能感对教师数字化教学意愿有显著的正向影响,并进一步正向影响教师的数字化教学能力;教师的自我效能感对数字化教学能力有显著的直接影响,且影响效应最强。而fs QCA分析结果显示,存在四条激发教师数字化教学能力的路径,在这些路径中数字化教学意愿和自我效能感是两个重要的前因变量,这弥补了结构方程模型分析的相对不足。文章通过研究,旨在为教育数字化转型时期教师数字化教学能力的提升提供实证依据。 展开更多
关键词 数字化教学能力 技术统一接受理论 偏最小二乘结构方程模型 模糊集定性比较分析
在线阅读 下载PDF
基于PLS模型的镉与微塑料复合污染对冬小麦植株生理和土壤理化性质影响
19
作者 陈悦 程海宽 +2 位作者 陈富鹏 丰晨晨 林迪 《环境科学》 北大核心 2025年第3期1815-1830,共16页
探究重金属、微塑料及二者复合污染对冬小麦生长、生理生态及土壤理化性质影响效应,确定关键影响因子,为重金属和微塑料污染生理机制阐释以及污染土壤的生态修复提供理论基础.采用室内土壤盆栽试验,以冬小麦(Triticum aestivum L.)为研... 探究重金属、微塑料及二者复合污染对冬小麦生长、生理生态及土壤理化性质影响效应,确定关键影响因子,为重金属和微塑料污染生理机制阐释以及污染土壤的生态修复提供理论基础.采用室内土壤盆栽试验,以冬小麦(Triticum aestivum L.)为研究对象,开展土壤重金属镉(Cd)(0 mg·kg^(-1)和5 mg·kg^(-1))与不同粒径(10μm和500μm)和质量分数(0、0.5%、1.0%、5.0%)聚丙烯微塑料(PP-MPs)单一及复合污染对冬小麦生长发育、光合生理、抗氧化酶活性、叶片解剖结构、冠层温度、土壤养分及土壤酶活性影响效应研究.同时利用偏最小二乘(PLS)回归模型定量分析各理化特性与冬小麦生长指标间关系,确定关键主控因子.结果表明,小粒径PP-MPs单一及其与Cd复合污染条件下,冬小麦株高显著降低了10.3%~59.9%,叶面积显著降低了5.8%~94.2%,总生物量显著降低了20.0%~84.0%.另外,二者污染条件下,小麦叶片光合效率、叶绿素含量等光合特性明显受到抑制.随两者污染胁迫程度增加,小麦植株群体冠层温度升高,叶片厚度降低;与CK相比,叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)分别提高了13.4%~99.0%、45.5%~122.7%和2.8%~89.2%,且两者间交互效应达极显著水平(P<0.01).此外,Cd与PPMPs胁迫后略微增加了土壤有机质、碱解氮、速效磷和速效钾等养分含量,显著提高了土壤脲酶、酸性磷酸酶和脱氢酶活性.与单一污染因素相比,Cd与PP-MPs复合污染对冬小麦各指标影响均呈协同抑制效应,且10μm小粒径抑制效应明显强于500μm大粒径. PLS模型结果显示,土壤酸性磷酸酶为Cd与10μm小粒径PP-MPs复合污染胁迫下影响冬小麦生长发育指标变化的关键主控因子,土壤速效磷则为500μm大粒径PP-MPs关键影响因子.研究结果对于评估土壤-植株系统中重金属Cd与MPs复合污染的生态效应提供参考借鉴. 展开更多
关键词 冬小麦 镉(CD) 微塑料(MPs) 复合污染 生理特性 偏最小二乘(pls)回归模型
原文传递
一种新型水稻穗叶类病斑突变体pls1的基因克隆和功能分析
20
作者 韩沛洁 李飞 +4 位作者 叶春 盛怡乐 孙红正 李俊周 杜彦修 《植物遗传资源学报》 北大核心 2025年第8期1574-1586,共13页
水稻类病斑突变体在研究水稻细胞程序性死亡和广谱抗病性中具有重要作用,已报道的水稻类病斑主要发生在叶片上,少量发生在颖壳上。本研究中首次报道了水稻的一种穗叶类病斑突变体pls1(Panicle and leaf spot 1),其从三叶期叶片开始出现... 水稻类病斑突变体在研究水稻细胞程序性死亡和广谱抗病性中具有重要作用,已报道的水稻类病斑主要发生在叶片上,少量发生在颖壳上。本研究中首次报道了水稻的一种穗叶类病斑突变体pls1(Panicle and leaf spot 1),其从三叶期叶片开始出现红褐色斑点,随生育进程扩大,并扩展到其他器官。与以往报道的水稻类病斑突变体不同的是,pls1抽穗后稻穗枝梗和颖壳逐渐产生红褐色病斑,成熟期稻穗干枯,严重影响产量,是一种新类型的水稻类病斑。结合图位克隆和全基因组重测序发现pls1突变体产生了173403 bp的大片段缺失,导致7个基因缺失和1个基因启动子缺失。这8个基因中4个编码醇溶蛋白,另外3个在叶片和穗部表达量较低,只有Os12g0268000在叶片和稻穗中较其他器官有较高的表达量,推测PLS1为Os12g0268000,基因功能注释显示其编码色胺5-羟化酶。pls1突变体叶片中活性氧、过氧化氢、超氧阴离子过量积累,抗氧系统相关酶氧化物歧化酶、抗坏血酸过氧化物酶、过氧化氢酶和谷胱甘肽还原酶活性提高,发生细胞程序性死亡和叶绿体降解,降低光合能力。褪黑素在植物耐盐性中起重要作用。进一步的功能分析发现,缺失PLS1会抑制水稻中褪黑素合成相关酶基因OsTDC1、OsTDC3、OsSNAT1、OsASMT1和OsCOMT的表达,进而导致pls1突变体的耐盐性下降。综上,穗叶类病斑突变体pls1是一种新类型的水稻类病斑突变体,将为水稻类病斑研究提供新的种质材料;耐盐性的分析揭示了色胺5-羟化酶的新功能,为研究其在细胞程序性死亡和耐盐性中的机制提供了新视角。 展开更多
关键词 水稻 穗叶类病斑 pls1 褪黑色素 耐盐性
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部