检索结果-南通市图书馆

Analysis of temperature characteristics of high-speed train wheelset system under complex operating conditions

International Journal of Mechanical System Dynamics 2024年第3期4卷 331-345页

作者： Baosen Wang Yongqiang Liu Yingying Liao Yixuan Wang School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuangChina Hebei Key Laboratory of Mechanical Power and Transmission Control Shijiazhuang Tiedao UniversityShijiazhuangChina School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuangChina Taiyuan Vehicle Depot Daqin Railway Co.Ltd.TaiyuanChina

With the rapid advancements in high-speed train technology,the importance of ensuring the safety of train operations has become ***,being a critical component of train bogies,have garnered significant attention for their role in maintaining safety *** the temperature of bearings to evaluate their motion state is a common practice in high-speed trains,emphasizing the need for further research into temperature *** this study,a dynamic model is developed for the bearing rotor system of high-speed *** considering the contact points between raceways and rolling elements,the power loss in the bearing is obtained and a transient temperature-field model of the system is *** relationship between node temperature and factors such as ambient temperature,train running speed,and load is illustrated,with a detailed presentation of the influence of bearing fault type and size on node *** analysis results reveal that the node temperature increases with higher values corresponding to those quantifiable factors and is most affected by rolling element ***,it is observed that the temperature rises rapidly in the initial stage and gradually flattens out over *** comparative analysis of temperature under different fault conditions shows that the node temperature is most affected by the rolling element *** and actual line temperature data are used to verify the validity of the *** comparison results show that the simulation aligns well with experimental and line *** transient temperature-field model of the bearing rotor system in high-speed trains can effectively simulate and predict the temperature change process of each node of the *** simulation results hold certain theoretical guiding significance for further research and practical applications in ensuring train operation safety.

关键词： high-speed train dynamic model transient temperature field bearing fault line data

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine Learning-Based Temperature and Wind Forecasts in the Zhangjiakou Competition Zone during the Beijing 2022 Winter Olympic Games

引用

Journal of Meteorological Research 2024年第4期38卷 664-679页

作者： Zhuo SUN Jiangbo LI Ruiqiang GUO Yiran ZHANG Gang ZHU Xiaoliang YANG China Meteorological Administration Xiong'an Atmospheric Boundary Layer Key Laboratory Xiong'an New Area 071800 Hebei Key Laboratory of Meteorology and Ecological Environment Shijiazhuang 050021 Hebei Meteorological Observatory Shijiazhuang 050021 college of Computer and Cyber Security Hebei Normal UniversityShijiazhuang 050024

Weather forecasting for the Zhangjiakou competition zone of the Beijing 2022 Winter Olympic Games is a challenging task due to its complex *** weather prediction models generally perform poorly for cold air pools and winds over complex terrains,due to their low spatiotemporal resolution and limitations in the description of dynamics,thermodynamics,and microphysics in mountainous *** study proposes an ensemble-learning model,named ENSL,for surface temperature and wind forecasts at the venues of the Zhangjiakou competition zone,by integrating five individual models—linear regression,random forest,gradient boosting decision tree,support vector machine,and artificial neural network(ANN),with a ridge regression as meta *** ENSL employs predictors from the high-resolution ECMWF model forecast(ECMWF-HRES) data and topography data,and targets from automatic weather station *** categories of predictors(synoptic-pattern related fields,surface element fields,terrain,and temporal features) are fed into *** results demonstrate that ENSL achieves better performance and generalization than individual *** root-mean-square error(RMSE) for the temperature and wind speed predictions is reduced by 48.2% and 28.5%,respectively,relative to *** the gust speed,the performance of ENSL is consistent with ANN(best individual model) in the whole dataset,whereas ENSL outperforms on extreme gust samples(42.7% compared with 38.7% obtained by ECMWF-HRES in terms of RMSE reduction).Sensitivity analysis of predictors in the four categories shows that ENSL fits their feature importance rankings and physical explanations effectively.

关键词： machine learning ensemble learning post-processing cold air pools mountain Beijing 2022 Winter Olympic Games

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamically switchable porphyrin-based molecular tweezer for on-off fullerene recognition

引用

Chinese Chemical Letters 2024年第6期35卷 283-287页

作者： Zhimin Sun Xin-Hui Guo Yue Zhao Qing-Yu Meng Li-Juan Xing He-Lue Sun college of Chemistry and Materials Science Hebei Key Laboratory of Organic Functional MoleculesHebei Normal UniversityShijiazhuang 050024China

Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes *** syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene *** exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational ***,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the ***,the association-disassociation process can be switched reversibly and repeatedly.

关键词： Molecular tweezer Fullerene recognition Supramolecular chemistry Conformation conversion Coordination

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

AtVQ25 promotes salicylic acid-related leaf senescence by fine-tuning the self-repression of AtWRKY53

引用

Journal of Integrative Plant Biology 2024年第6期66卷 1126-1147页

作者： Qi Tan Mingming Zhao Jingwei Gao Ke Li Mengwei Zhang Yunjia Li Zeting Liu Yujia Song Xiaoyue Lu Zhengge Zhu Rongcheng Lin Pengcheng Yin Chunjiang Zhou Geng Wang Ministry of Education Key Laboratory of Molecular and Cellular Biology Hebei Research Center of the Basic Discipline of Cell BiologyHebei Collaboration Innovation Center for Cell Signaling and Environmental AdaptationHebei Key Laboratory of Molecular and Cellular BiologyCollege of Life SciencesHebei Normal UniversityShijiazhuang 050024China college of Chemical Engineering Shijiazhuang UniversityShijiazhuang 050035China Institute of Botany Chinese Academy of SciencesBeijing 100093China

Most mechanistic details of chronologically ordered regulation of leaf senescence are *** networks centered on AtWRKY53 are crucial for orchestrating and integrating various senescence-related ***,AtWRKY53binds to its own promoter and represses transcription of AtWRKY53,but the biological significance and mechanism underlying this selfrepression remain *** this study,we identified the VQ motif-containing protein AtVQ25as a cooperator of *** expression level of AtVQ25 peaked at mature stage and was specifically repressed after the onset of leaf ***25-overexpressing plants and atvq25 mutants displayed precocious and delayed leaf senescence,***,we identified AtWRKY53 as an interacting partner of *** determined that interaction between AtVQ25 and AtWRKY53 prevented AtWRKY53from binding to W-box elements on the AtWRKY53promoter and thus counteracted the selfrepression of *** addition,our RNA-sequencing data revealed that the AtVQ25-AtWRKY53 module is related to the salicylic acid(SA)*** leaf senescence and SA-induced leaf senescence in AtVQ25-overexpressing lines were inhibited by an SA pathway mutant,atsid2,and Nah G transgenic plants;AtVQ25-overexpressing/atwrky53 plants were also insensitive to SA-induced leaf ***,we demonstrated that AtVQ25 directly attenuates the self-repression of AtWRKY53 during the onset of leaf senescence,which is substantially helpful for understanding the timing of leaf senescence onset modulated by AtWRKY53.

关键词： AtWRKY53 leaf senescence salicylic acid transcriptional regulation VQ motif-containing proteins

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quercetin regulates depression-like behavior in CUMS rat models via TLR4/NF-κB signaling

引用

BIOCELL 2024年第5期48卷 731-744页

作者： YUANYUAN LI BITAO ZHANG ZILONG CUI PEIJIAN FAN SHAOXIAN WANG college of Basic Medicine Hebei University of Chinese MedicineShijiazhuang050200China Hebei Key Laboratory of Integrated Chinese and Western Medicine for Lung Disease Research Shijiazhuang050091China

Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as *** is known to be highly effective in treating ***,additional research is needed to dissect the mechanisms of its anti-depressive ***:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine *** latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 *** first two groups received saline solution daily via oral ***,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of *** experimental period was 6 *** behaviors in rats were assessed through various physiological and behavioral ***,pathological changes in hippocampal tissues were examined using Nissl *** cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the ***-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in *** blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field *** analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure

关键词： Quercetin Chronic unpredictable mild stress Depression Microglia TLR4/NF-κB inflammatory pathway

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Influence of vapor pressure deficit on vegetation growth in China

引用

Journal of Arid Land 2024年第6期16卷 779-797页

作者： LI Chuanhua ZHANG Liang WANG Hongjie PENG Lixiao YIN Peng MIAO Peidong college of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Hebei First Surveying and Mapping Institute Shijiazhuang 050000China

Vapor pressure deficit(VPD)plays a crucial role in determining plant physiological functions and exerts a substantial influence on vegetation,second only to carbon dioxide(CO_(2)).As a robust indicator of atmospheric water demand,VPD has implications for global water resources,and its significance extends to the structure and functioning of ***,the influence of VPD on vegetation growth under climate change remains unclear in *** study employed empirical equations to estimate the VPD in China from 2000 to 2020 based on meteorological reanalysis data of the Climatic Research Unit(CRU)Time-Series version 4.06(TS4.06)and European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA-5).Vegetation growth status was characterized using three vegetation indices,namely gross primary productivity(GPP),leaf area index(LAI),and near-infrared reflectance of vegetation(NIRv).The spatiotemporal dynamics of VPD and vegetation indices were analyzed using the Theil-Sen median trend analysis and Mann-Kendall ***,the influence of VPD on vegetation growth and its relative contribution were assessed using a multiple linear regression *** results indicated an overall negative correlation between VPD and vegetation *** VPD intervals for the correlations between VPD and vegetation indices were identified:a significant positive correlation at VPD below 4.820 hPa,a significant negative correlation at VPD within 4.820–9.000 hPa,and a notable weakening of negative correlation at VPD above 9.000 *** exhibited a pronounced negative impact on vegetation growth,surpassing those of temperature,precipitation,and solar radiation in absolute ***_(2) contributed most positively to vegetation growth,with VPD offsetting approximately 30.00%of the positive effect of CO_(2).As the rise of VPD decelerated,its relative contribution to vegetation growth ***,the intensification of spatial variations in temperature an

关键词： vapor pressure deficit(VPD) near-infrared reflectance of vegetation(NIRv) leaf area index(LAI) gross primary productivity(GPP) Climatic Research Unit(CRU)Time-Series version 4.06(TS4.06) European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA-5) climate change

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Layered(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]with a large birefringence derived from the uniform arrangement of π-conjugated units

引用

Chinese Journal of Structural Chemistry 2024年第6期43卷 50-55页

作者： Dong-Xue Jiao Hui-Li Zhang Chao He Si-Yu Chen Ke Wang Xiao-Han Zhang Li Wei Qi Wei college of Chemistry and Chemical Engineering Qingdao UniversityShandong266071PR China college of Science Hebei University of Science and TechnologyShijiazhuangHebei050018PR China

An organic-inorganic hybrid antimony(Ⅲ)oxalate(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]has been successfully obtained by simultaneous combination of a-conjugated 4-hydroxypyridine and(C_(2)O_(4))^(2-)group with stereochemical active Sb(Ⅲ)*** compound features a layered structure,and the equatorial planes of SbO6 units,π-conjugated(C_(2)O_(4))^(2-)and(C5H6ON)+groups are closer to a planar arrangement,representing strong structural anisotropy that favors a large *** expected,(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]exhibits a large birefringence of 0.279 at 546 *** and theoretical analyses indicate that the combination of multipleπ-conjugated units is a feasible approach for designing and exploring new superior birefringent materials.

关键词： Organicπ-conjugated unit Birefringence Stereochemically active lone pair Layered structure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Differences and similarities in radial growth of Betula species to climate change

引用

Journal of Forestry Research 2024年第2期35卷 176-187页

作者： Di Liu Yang An Zhao Li Zhihui Wang Yinghui Zhao Xiaochun Wang Center for Ecological Research Key Laboratory of Sustainable Forest Ecosystem ManagementMinistry of EducationCollege of ForestryNortheast Forestry UniversityHarbin 150040People’s Republic of China Changan Park in shijiazhuang Shijiazhuang 050000People’s Republic of China shijiazhuang Landscape Greening Engineering Project Construction Center Shijiazhuang 050000People’s Republic of China Heilongjiang Institute of Meteorological Science Harbin 150030People’s Republic of China School of Life Qufu Normal UniversityQufu 273100People’s Republic of China

Betula platyphylla and Betula costata are important species in mixed broadleaved-Korean pine(Pinus koraiensis)***,the specific ways in which their growth is affected by warm temperatures and drought remain *** address this issue,60 and 62 tree-ring cores of *** and *** were collected in Yichun,*** dendrochronological methods,the response and adaptation of these species to climate change were examined.A“hysteresis effect”was found in the rings of both species,linked to May–September moisture conditions of the previous *** growth of *** was positively correlated with the standardized precipitation-evapotranspiration index(SPEI),the precipitation from September to October of the previous year,and the relative humidity in October of the previous *** of *** is primarily restricted by moisture conditions from September to *** contrast,*** growth is mainly limited by minimum temperatures in May–June of both the previous and current *** droughts,*** had a faster recovery rate compared to *** the context of rising temperatures since 1980,the correlation between *** growth and monthly SPEI became positive and strengthened over time,while the growth of *** showed no conspicuous *** findings suggest that the growth of *** is already affected by warming temperatures,whereas *** may become limited if warming continues or *** change could disrupt the succession of these species,possibly accelerating the succession of pioneer *** results of this research are of great significance for understanding how the growth changes of birch species under warming and drying conditions,and contribute to understanding the structural adaptation of mixed broadleaved-Korean pine(Pinus koraiensis)forests under climate change.

关键词： Tree rings Betula platyphylla Betula costata Climate response Moving correlation Extreme drought

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dendritic mesoporous silica nanoparticles for enzyme immobilization

引用

Green Chemical Engineering 2024年第2期5卷 173-186页

作者： Shuling Zhang Jing Bai Weixi Kong Haolei Song Yunting Liu Guanhua Liu Li Ma Liya Zhou Yanjun Jiang School of Chemical Engineering and Technology Hebei University of TechnologyTianjin300130China college of Food Science and Biology Hebei University of Science&TechnologyShijiazhuang050018China Hebei Yanuo Bioscience Co. Ltd.Shijiazhuang052165China

Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent *** this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like *** DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively *** directions for future research on enzyme immobilization using DMSNs are also proposed.

关键词： Dendritic mesoporous silica nanoparticles Enzyme immobilization Flower-like Tree-branch-like Central-radial structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Demonstration of safety characteristics and effects on gut microbiota of Lactobacillus gasseri HMV18

引用

Food Science and Human Wellness 2024年第2期13卷 611-620页

作者： Xianxian Jia Miaomiao Jia Xiang Gao Xiang Li Mengyuan Wang Shengqiang Du Rui Huang Xiaotong Li Jun Zhang Shujin Li Chunling Ma Yan Zhang Bin Cong Department of Pathogen Biology Institute of basic MedicineHebei Medical UniversityShijiazhuang 050017China Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology Chinese Academy of Medical SciencesShijiazhuang 050017China Institute of Basic Medicine Hebei Medical UniversityShijiazhuang 050017China college of Forensic Medicine Hebei Key Laboratory of Forensic MedicineCollaborative Innovation Center of Forensic Medical Molecular IdentificationHebei Medical UniversityShijiazhuang 050017China Hebei Food Safety Key Laboratory Hebei Food Inspection and Research InstituteShijiazhuang 050227China

Human normal flora is a source of *** safety characteristics of a specific isolate determine its application in foods or *** food-borne-pathogen antagonist strain Lactobacillus gasseri HMV18 is one of the isolates from normal human *** this work,we assessed the in vitro pH tolerance,bile tolerance,biogenic amine production,mucin utilization,and safety of in vivo administration to mice to evaluate general health,organ-body weight index,organ histopathological change,whether *** HMV18 can colonize in the gut or modulate the gut microbiota after oral *** results suggest that *** HMV18 can tolerate pH 3 for 2 h,3%bile for 3 h,biogenic amine negative,mucin usage negative,does not encode verified toxins,and cause no visible change in mice's *** HMV18 might not colonize in mice's gut,but can significantly affect the structure of gut microbiota.A bibliographical survey suggested that there were as few as 8 opportunistic infection cases from 1984 to 2022 and that the possibility for *** to cause infection is relatively ***,this work provides a basis for the foods or drugs application of *** HMV18 and gives a map of experiments for the safety assessment of probiotics.

关键词： Probiotics Lactobacillus gasseri Safety assessment Gut microbiota

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：