检索结果-南通市图书馆

Mitigation of Deane and Hamill phenomenon in gallium nitride high-voltage power supply for electric propulsion system application

引用

High Voltage 2024年第1期9卷 252-265页

作者： Minghai Dong Hui Li Shan Yin Kye Yak See Yingzhe Wu xiong xin School of Aeronautics&Astronautics University of Electronic Science and Technology of ChinaChengduChina School of Electrical&Electronic Engineering Nanyang Technological UniversitySingaporeSingapore School of Automation Engineering University of Electronic Science and Technology of ChinaChengduChina Innoscience(Shenzhen)Semiconductor Co.Ltd. ShenzhenChina

The step-up resonant converters are widely adopted to provide high voltage in kV-level for electric propulsion system due to their high efficiency,low mass,modularisation,and high-power *** bipolar Cockcroft-Walton voltage multiplier(BiCWVM)is a major circuit that steps up the voltage in the resonant ***,the diode nonlinearity in BiCWVM can introduce self-sustained quasi-periodic oscillations in the voltage and current waveforms,which is commonly known as the Deane and Hamill(DH)*** oscillation can lead to higher magnetic loss and control failure,and it is more likely to present in the gallium nitride-based converter due to the highfrequency *** authors aim to investigate and mitigate the DH phenomenon systematically so that proper mitigation can be *** facilitate the investigation,the circuit before the BiCWVM in the converter is derived and modelled as a voltage source v_(m)and a series inductor L_(sy).Also,the reverse recovery process of the diode in the BiCWVM can be represented by a piecewise-linear(PWL)model,with the simplified circuit and PWL model,the relationship between voltage and current under different operating conditions can be determined with *** relationship allows to understand the mechanism of diode reverse recovery in BiCWVM that leads to DH ***,a hybrid-/full-silicon carbide(SiC)design is proposed to mitigate the DH phenomenon,which is verified experimentally for a 300-kHz,5-W,20-V/1.5-kV GaN-based step-up resonant converter.

关键词： power resonant high

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

Exploring Motor Imagery EEG: Enhanced EEG Microstate Analysis with GMD-Driven Density Canopy Method

引用

Computers, Materials & Continua 2024年第6期79卷 4659-4681页

作者： xin xiong Jing Zhang Sanli Yi Chunwu Wang Ruixiang Liu Jianfeng He Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming650500China College of Physics and Electronic Engineering Hanshan Normal UniversityChaozhou521041China Department of Clinical Psychology Second People’s Hospital of YunnanKunming650021China

The analysis of microstates in EEG signals is a crucial technique for understanding the spatiotemporal dynamics of brain electrical *** methods such as Atomic Agglomerative Hierarchical Clustering(AAHC),K-means clustering,Principal Component Analysis(PCA),and Independent Component Analysis(ICA)are limited by a fixed number of microstate maps and insufficient capability in cross-task feature *** these limitations,this study introduces a Global Map Dissimilarity(GMD)-driven density canopy K-means clustering *** innovative approach autonomously determines the optimal number of EEG microstate topographies and employs Gaussian kernel density estimation alongside the GMD index for dynamic modeling of EEG *** this advanced algorithm,the study analyzes the Motor Imagery(MI)dataset from the GigaScience database,*** findings reveal six distinct microstates during actual right-hand movement and five microstates across other task conditions,with microstate C showing superior performance in all task *** imagined movement,microstate A was significantly *** with existing algorithms indicates a significant improvement in clustering performance by the refined method,with an average Calinski-Harabasz Index(CHI)of 35517.29 and a Davis-Bouldin Index(DBI)average of ***,an information-theoretical analysis of the microstate sequences suggests that imagined movement exhibits higher complexity and disorder than actual *** utilizing the extracted microstate sequence parameters as features,the improved algorithm achieved a classification accuracy of 98.41%in EEG signal categorization for motor imagery.A performance of 78.183%accuracy was achieved in a four-class motor imagery task on the BCI-IV-2a *** results demonstrate the potential of the advanced algorithm in microstate analysis,offering a more effective tool for a deeper understanding of the spatiotemporal features of EE

关键词： EEG microstate motor imagery K-means clustering algorithm gaus sian kernel function shannon entropy Lempel-Ziv complexity

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

Association between childhood obesity and gut microbiota:16S rRNA gene sequencing-based cohort study

引用

World Journal of Gastroenterology 2024年第16期30卷 2249-2257页

作者： Xu-Ming Li Qing Lv Ya-Jun Chen Lu-Biao Yan xin xiong Laboratory Department Nanjing Medical University Affiliated Obstetrics and Gynecology Hospital(Nanjing Maternal and Child Health Hospital)Nanjing 210004Jiangsu ProvinceChina Department of Pediatrics Shenzhen University General HospitalShenzhen 518055Guangdong ProvinceChina Department of Inspection Division Women’s Hospital of Nanjing Medical University(Nanjing Maternity and Child Health Care Hospital)Nanjing 210004Jiangsu ProvinceChina Department of Pediatrics Women’s Hospital of Nanjing Medical University(Nanjing Maternity and Child Health Care Hospital)Nanjing 210004Jiangsu ProvinceChina Department of Neonatology Chenzhou First People’s HospitalChenzhou 423000Hunan ProvinceChina

BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA *** research aimed to provide insights for mechanistic studies and prevention strategies for childhood *** normal-weight and thirty age-and sex-matched obese children were *** and body measurements were collected,and fecal samples underwent 16S rDNA *** differences in body mass index(BMI)and body-fat percentage were observed between the *** of gut microbiota diversity revealed lowerα-diversity in obese *** in gut microbiota composition were found between the two *** and Firmicutes were more abundant in the obese group,while Bacteroides and Sanguibacteroides were more prevalent in the control *** To identify the characteristic gut genera in obese and normal-weight children(8-12-year-old)using 16S rDNA sequencing,and provide a basis for subsequent mechanistic studies and prevention strategies for childhood *** Thirty each normal-weight,1:1 matched for age and sex,and obese children,with an obese status from 2020 to 2022,were included in the control and obese groups,*** information was collected through questionnaires and body measurements were obtained from both obese and normal-weight *** samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity *** Significant differences in BMI and body-fat percentage were observed between the two *** Ace and Chao1 indices were significantly lower in the obese group than those in the control group,whereas differences were not significant in the Shannon and Simpson ***-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children(P<0.01),suggest

关键词： Childhood obesity Gut microbiota 16S rDNA sequencing Diversity analysis Genus identification Body mass index

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

Comparative analysis of primate and pig cells reveals primate-specific PINK1 expression and phosphorylation

引用

Zoological Research 2024年第2期45卷 242-252页

作者： Xiu-Sheng Chen Rui Han Yan-Ting Liu Wei Huang Qi Wang xin xiong Ying Zhang Jian-Guo Zhao Shi-Hua Li Xiao-Jiang Li Wei-Li Yang Guangdong Key Laboratory of Non-human Primate Research Key Laboratory of CNS Regeneration(Ministry of Education)GHM Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong 510632China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China

PTEN-induced putative kinase 1(PINK1),a mitochondrial kinase that phosphorylates Parkin and other proteins,plays a crucial role in mitophagy and protection against *** in PINK1 and Parkin can lead to loss of function and early onset Parkinson's ***,there is a lack of strong in vivo evidence in rodent models to support the theory that loss of PINK1 affects mitophagy and induces ***,PINK1 knockout pigs(Sus scrofa)do not appear to exhibit *** our recent work involving non-human primates,we found that PINK1 is selectively expressed in primate brains,while absent in rodent *** extend this to other species,we used multiple antibodies to examine the expression of PINK1 in pig *** contrast to tissues from cynomolgus monkeys(Macaca fascicularis),our data did not convincingly demonstrate detectable PINK1expression in pig *** of PINK1 in cultured pig cells did not result in altered Parkin and BAD phosphorylation,as observed in cultured monkey cells.A comparison of monkey and pig striatum revealed more PINK1-phosphorylated substrates in the monkey ***,PINK1 knockout in pigs did not lead to obvious changes in the phosphorylation of Parkin and *** findings provide new evidence that PINK1expression is specific to primates,underscoring the importance of non-human primates in investigating PINK1function and pathology related to PINK1 deficiency.

关键词： PINK1 Parkin Mitochondria Phosphorylation Non-human primates Pigs

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

Precisely manipulation of core composition of core-shell-type cobalt polyoxoniobates and proton conduction study

引用

Chinese Chemical Letters 2024年第1期35卷 510-513页

作者： Zheng-Wei Guo Yi Chen Zhe-Hong Chen xin-xiong Li Shou-Tian Zheng State Key Laboratory of Photocatalysis on Energy and Environment School of ChemistryFuzhou UniversityFuzhou 350108China

The development of core-shell nanoclusters with controllable composition is of utmost importance as the material properties depend on their constituent ***,precisely tuning their compositions at the atomic scale is not easily achieved because of the difficulty of using limited macroscopic synthetic methods for atomic-level *** this work,we report an interesting example of precisely regulating the core composition of an inorganic core-shell-type cobalt polyoxoniobate[Co_(26)Nb_(36)O_(140)]^(32−)by controlling reaction conditions,in which the inner Co-core composition could be tune while retaining the outer Nb-shell composition of resulting product,leading to a series of isostructural species with a general formula of{Co_(26-n)Nb_(36+n)O_(140)}(n=0–2).These rare species not only can display good powder and single-crystal proton conductivities,but also might provide helpful and atomic-level insights into the syntheses,structures and composition modifications of inorganic amorphous core-shell heterometal oxide nanoparticles.

关键词： Polyoxoniobate Core-shell Nanocluster Atomic-level modulation Proton conduction

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

Artificial intelligence models based on non-contrast chest CT for measuring bone mineral density

引用

中国医学影像技术 2024年第8期40卷 1231-1235页

作者： DUAN Wei YANG Guoqing LI Yang SHI Feng YANG Lian xiong xin CHEN Bei LI Yong FU Quanshui Department of Medical Imaging North Sichuan Medical CollegeNanchong 637000China Department of Radiology Suining Central HospitalSuining 629000China Department of Radiology Suining Hospital of Traditional Chinese MedicineSuining 629000China Shanghai United Imaging Intelligence Co.Ltd. Shanghai 201807China

Objective To observe the value of artificial intelligence(AI)models based on non-contrast chest CT for measuring bone mineral density(BMD).Methods Totally 380 subjects who underwent both non-contrast chest CT and quantitative CT(QCT)BMD examination were retrospectively enrolled and divided into training set(n=304)and test set(n=76)at a ratio of 8∶*** mean BMD of L1—L3 vertebrae were measured based on *** bones of T5—T10 vertebrae were segmented as ROI,radiomics(Rad)features were extracted,and machine learning(ML),Rad and deep learning(DL)models were constructed for classification of osteoporosis(OP)and evaluating BMD,*** operating characteristic curves were drawn,and area under the curves(AUC)were calculated to evaluate the efficacy of each model for classification of ***-Altman analysis and Pearson correlation analysis were performed to explore the consistency and correlation of each model with QCT for measuring *** Among ML and Rad models,ML Bagging-OP and Rad Bagging-OP had the best performances for classification of *** test set,AUC of ML Bagging-OP,Rad Bagging-OP and DL OP for classification of OP was 0.943,0.944 and 0.947,respectively,with no significant difference(all P>0.05).BMD obtained with all the above models had good consistency with those measured with QCT(most of the differences were within the range of Ax-G±1.96 s),which were highly positively correlated(r=0.910—0.974,all P<0.001).Conclusion AI models based on non-contrast chest CT had high efficacy for classification of OP,and good consistency of BMD measurements were found between AI models and QCT.

关键词： osteoporosis bone density tomography,X-ray computed artificial intelligence

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

Differential distribution of PINK1 and Parkin in the primate brain implies distinct roles

引用

Neural Regeneration Research 2025年第4期20卷 1124-1134页

作者： Yanting Liu Wei Huang Jiayi Wen xin xiong Ting Xu Qi Wang Xiusheng Chen Xianxian Zhao Shihua Li Xiaojiang Li Weili Yang Guangdong Key Laboratory of Non-human Primate Research Key Laboratory of CNS Regeneration(Ministry of Education)Guangdong-Hongkong-Macao CNS Regeneration Institute of Jinan UniversityJinan UniversityGuangzhouGuangdong ProvinceChina

The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal ***,it remains largely unclear how PINK1 and Parkin are expressed in mammalian *** has been difficult to address because of the intrinsically low levels of PINK1 and undetectable levels of phosphorylated Parkin in small *** this issue is critical for elucidating the in vivo roles of PINK1 and ***,we showed that the PINK1 kinase is selectively expressed as a truncated form(PINK1–55)in the primate *** the present study,we used multiple antibodies,including our recently developed monoclonal anti-PINK1,to validate the selective expression of PINK1 in the primate *** found that PINK1 was stably expressed in the monkey brain at postnatal and adulthood stages,which is consistent with the findings that depleting PINK1 can cause neuronal loss in developing and adult monkey ***1 was enriched in the membrane-bound fractionations,whereas Parkin was soluble with a distinguishable *** double staining experiments showed that PINK1 and Parkin did not colocalize under physiological conditions in cultured monkey astrocytes,though they did colocalize on mitochondria when the cells were exposed to mitochondrial *** findings suggest that PINK1 and Parkin may have distinct roles beyond their well-known function in mitophagy during mitochondrial damage.

关键词： neurodegeneration Parkin Parkinson’s disease PINK1 subcellular distribution

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

餐饮和零售行业热点区块提取与空间分布特征聚类分析

引用

测绘科学 2024年第6期49卷 203-210页

作者：郭名静熊鑫东华理工大学理学院南昌330013 海军工程大学教研保障中心武汉430033

针对城市餐饮和零售行业热点区块提取方法中位置数据多维属性特征融合处理问题,该文提出引入非位置属性特征权重系数进行热点区块聚类分析,基于密度聚类分析方法建立了加权密度聚类模型,以新浪微博兴趣点数据为样本实证研究了武汉市部... 详细信息

针对城市餐饮和零售行业热点区块提取方法中位置数据多维属性特征融合处理问题,该文提出引入非位置属性特征权重系数进行热点区块聚类分析,基于密度聚类分析方法建立了加权密度聚类模型,以新浪微博兴趣点数据为样本实证研究了武汉市部分服务业在样本期内的城市热点区块,分析了城市服务业空间分布的影响因素。研究发现,城市餐饮和零售业在整体上表现出较为明显的行业空间聚集性,城市热点区块的区域分布相对均衡,行业发展容易受到城市圈扩张的拉动效应影响。对比传统聚类分析方法,研究结果验证了加权密度聚类算法对样本城市热点区块提取具有明显优化效果,能提高提取出的城市热点区块的高热性。

关键词：城市热点区块空间分布特征位置数据基于密度聚类分析

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

洞庭湖区生态承载力与高质量发展的非协调性耦合时空格局

引用

长江流域资源与环境 2024年第5期33卷 949-960页

作者：熊建新王鑫滨王静刘玫君张家雄湖南理工学院经济与管理学院湖南岳阳414000

揭示生态承载力与高质量发展的非协调性耦合关系对促进生态安全和人地协调发展具有重要现实意义。基于非协调性耦合作用机理,从生态弹性、资源承载和环境承载3个维度,创新驱动、协调能力、绿色转型、开放水平和共享发展5个维度构建生态... 详细信息

揭示生态承载力与高质量发展的非协调性耦合关系对促进生态安全和人地协调发展具有重要现实意义。基于非协调性耦合作用机理,从生态弹性、资源承载和环境承载3个维度,创新驱动、协调能力、绿色转型、开放水平和共享发展5个维度构建生态承载力与高质量发展评价指标体系,运用非协调性耦合模型、探索性空间数据分析法、标准差椭圆和GM(1,1)模型,分析2004~2022年洞庭湖区生态承载力与高质量发展的非协调性耦合时空格局特征,预测2023~2028年变化趋势。结果表明:(1)2004~2022年非协调性耦合度由0.5323下降至0.3631,预测2028年为0.3092,仍处于拮抗阶段,耦合性与协调性不同步;空间差异明显,基本形成中部地区>外围地区>边缘地区的空间分布格局。(2)非协调性耦合度具有显著的负向全局空间自相关性,预计2028年耦合协调类型仍以拮抗非协调耦合为主,非协调性耦合态势依然严峻,空间集聚类型将出现高—高、高—低和低—高3种。(3)非协调性耦合度空间分布的方向性以东西向为主导,且向洞庭湖西北方向缓慢移动,集聚性及重心位置基本稳定。(4)洞庭湖边缘地区应稳步降低自身非协调性耦合度的同时,发挥带动与辐射作用;中部地区应加强区域合作,发挥水土资源优势,推进生态农业;外围地区应因地制宜,发展特色生态产业。

关键词：生态承载力高质量发展非协调性耦合时空格局洞庭湖区

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

四川扎乌龙伟晶岩型稀有金属矿床的成矿机制及找矿标志

引用

岩石学报 2024年第9期40卷 2863-2877页

作者：熊欣李建康严清高中国地质科学院矿产资源研究所自然资源部成矿作用与资源评价重点实验室北京100037 昆明理工大学国土资源工程学院昆明650093

扎乌龙稀有金属矿床位于松潘-甘孜造山带,属于伟晶岩型锂辉石矿床,同时伴生铍和铌钽矿化。本文总结了扎乌龙矿床地球化学和矿物学特征,初步梳理了矿床成矿模式,并指出含矿性评价与找矿标志。扎乌龙伟晶岩脉在空间上围绕白云母花岗岩分布... 详细信息

扎乌龙稀有金属矿床位于松潘-甘孜造山带,属于伟晶岩型锂辉石矿床,同时伴生铍和铌钽矿化。本文总结了扎乌龙矿床地球化学和矿物学特征,初步梳理了矿床成矿模式,并指出含矿性评价与找矿标志。扎乌龙伟晶岩脉在空间上围绕白云母花岗岩分布,具有类似的稀土元素和微量元素配分模式,但其稀土元素含量明显低于白云母花岗岩,表明伟晶岩脉为白云母花岗熔体分异演化的产物。扎乌龙白云母花岗岩岩石地球化学组分呈现高Rb/Sr和Rb/Ba、低CaO/Na_(2)O壳源特征,具有接近地壳的Sr-Nd-Hf同位素组成,表明其来源于松潘-甘孜大规模造山运动导致的西康群变泥质岩的深部重熔。矿物学和流体包裹体特征显示,扎乌龙伟晶岩脉的形成可划分为岩浆阶段和热液阶段。岩浆阶段主要结晶稀有金属矿物,如锂辉石、绿柱石和铌钽铁矿族矿物;热液阶段主要为原生矿物与流体发生再平衡,如原生锂辉石发生蚀变形成云母等矿物,原生绿柱石边部和内部缝隙产出相对富Cs_(2)O或Na_(2)O的次生绿柱石。锂矿物主要沉淀于相对封闭、高压(350MPa)的伟晶岩岩浆阶段。氢、氧同位素组成表明成矿流体主要来源于岩浆水,晚期流体来源于伟晶岩熔体的自身分异演化。扎乌龙锂辉石伟晶岩熔体分异程度属于中等,远低于高分异的新疆可可托海三号伟晶岩脉,而高于低分异的南爱尔兰Leinster伟晶岩脉。地质背景条件、围岩标志、断裂构造条件、矿物标型、物化探异常标志、遥感图像可作为扎乌龙重要找矿标志。

关键词：松潘-甘孜造山带扎乌龙矿床稀有金属伟晶岩锂辉石成矿规律

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

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：