检索结果-南通市图书馆

基于变载波频率的永磁同步电机驱动系统效率优化控制

在线全文

学校读者我要写书评

暂无评论

东南大学学报（自然科学版） 2024年第3期54卷 724-729页

作者：刘凯张阔花为胡铭觐东南大学电气工程学院南京210096

为降低永磁同步电机驱动系统的损耗,提高系统效率,提出了一种基于母线电流反馈的变载波频率优化控制方法.首先,建立了系统损耗数学模型,探究了载波频率与系统损耗的关系.然后,针对离线优化方法对于参数敏感的问题,设计了一种基于母线电... 详细信息

为降低永磁同步电机驱动系统的损耗,提高系统效率,提出了一种基于母线电流反馈的变载波频率优化控制方法.首先,建立了系统损耗数学模型,探究了载波频率与系统损耗的关系.然后,针对离线优化方法对于参数敏感的问题,设计了一种基于母线电流反馈的载波频率在线寻优方法.结果表明,在不同转速与负载条件下均存在使系统损耗最小的最优载波频率,其随转速与负载条件变化而变化.在各个工作点,系统损耗的计算值均与实测值基本吻合.在线寻优方法在中高负载情况下能够实现约0.6%的效率优化,并且在负载变化的情况下仍然能够实现损耗优化.

关键词：变载波频率损耗模型效率优化永磁同步电机

在线全文

学校读者我要写书评

暂无评论

面向结构静力试验监测的高精度数字孪生方法

航空学报 2024年第7期45卷 283-294页

作者：田阔孙志勇李增聪大连理工大学工业装备结构分析国家重点实验室工程力学系大连116024

试验验证和数值仿真是评估结构强度的两种典型方法,然而基于离散传感器的试验验证方法难以保证结构应力监测覆盖度,数值仿真方法又因为对物理实体的简化和理想化处理而导致应力结果精度不足,如何综合利用两种强度评估方法的优势并进行... 详细信息

试验验证和数值仿真是评估结构强度的两种典型方法,然而基于离散传感器的试验验证方法难以保证结构应力监测覆盖度,数值仿真方法又因为对物理实体的简化和理想化处理而导致应力结果精度不足,如何综合利用两种强度评估方法的优势并进行数据融合以实现结构应力场监测是一个具有挑战性的问题。提出一种面向结构静力试验监测的数字孪生(DT-SSTM)方法,可获得高精度的结构静力试验数字孪生模型,以实现结构应力场的实时监测与强度评估。DT-SSTM方法包括离线、在线2.阶段。离线阶段,采用梯度提升树(GBDT)算法对仿真数据进行训练,建立预训练模型。在线阶段,基于集成学习理论,采用Stacking算法对试验数据响应值与预训练模型响应值之间的残差进行训练并建立残差模型。通过叠加预训练模型与残差模型实现多源数据融合,建立高精度的数字孪生模型。最后,开展了开口矩形壁板轴向拉伸试验来验证DT-SSTM方法的有效性。结果表明,DT-SSTM方法能够建立高精度的结构静力试验数字孪生模型,且相比同类数据融合方法具有更高的全局、局部预测精度以及融合效率,为结构应力场实时监测提供了一种新颖的解决方案。

关键词：数字孪生壁板结构数据融合应力场监测集成学习

Electrical performance and reliability analysis of vertical gallium nitride Schottky barrier diodes with dual-ion implanted edge termination

在线全文

学校读者我要写书评

暂无评论

Chip 2024年第3期3卷 36-42页

作者： Bo Li Jinpei Lin Linfei Gao Zhengweng Ma Huakai Yang Zhihao Wu Hsien-Chin Chiu Hao-Chung kuo Chunfu Zhang Zhihong Liu Shuangwu Huang Wei He Xinke Liu College of Materials Science and Engineering College of Electronics and Information EngineeringInstitute of Microelectronics(IME)Guangdong Research Center for Interfacial Engineering of Functional MaterialsState Key Laboratory of Radio Frequency Heterogeneous IntegrationShenzhen UniversityShenzhen 518060China Department of Electronic Engineering Chang Gung UniversityTaoyuan 333TaiwanChina Department of Photonics and the Institute of Electro-Optical Engineering and with Foxconn Semiconductor Research InstituteNational Chiao Tung UniversityHsinchu 300TaiwanChina Xidian University School of MicroelectronicsXi’an710071China

In this study,a galliumnitride(GaN)substrate and its 15μmepitaxial layer were entirely grown by adopting the hydride vapor phase epitaxy(HVPE)*** enhance the breakdown voltage(VBR)of vertical GaN-on-GaN Schottky barrier diodes(SBDs),a dual ion coimplantation of carbon and heliumwas employed to create the edge *** resulting devices exhibited a low turn-on voltage of 0.55 V,a high Ion/Ioff ratio of approximately 109,and a lowspecific onresistance of 1.93 mU cm^(2..When the ion implantation edge was terminated,the maximumVBR of the devices reached 1575 V,with an average improvement of 12.%.These devices demonstrated a high figure of merit(FOM)of 1.2. GW cm^(-2. and showed excellent reliability during pulse stress testing.

关键词： Vertical GaN SBD HVPE Dual ion co-implantation Leakage mechanism Device reliability

达芬奇机器人保留乳头乳晕乳腺切除即刻假体乳房重建术中预防热蒸汽损伤皮肤组织临床研究

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

中国修复重建外科杂志 2024年第7期38卷 813-817页

作者：陈阔吕鹏威郑州大学第一附属医院乳腺外科郑州450052

目的探讨达芬奇机器人保留乳头乳晕乳腺切除即刻假体乳房重建术(robotic nipple-sparing mastectomy and immediate breast reconstruction,R-NSM-IBR)中预防热蒸汽损伤皮肤组织的方法。方法回顾性分析2.2.年9月—2.2.年12.接受R-NSM-IBR治疗且符合选择标准的12.例乳腺癌女性患者临床资料。术中乳腺切除期间,99例采用覆盖冰水冷却后纱布来降低乳房皮肤温度(A组),2.例不作处理(B组)。两组患者年龄、手术侧别、身体质量指数、乳腺癌病理类型及接受辅助化疗、新辅助化疗构成比比较,差异均无统计学意义(P>0.05)。记录并比较术中乳房表面温度、单侧乳腺切除时间以及术中乳房热损伤并发症发生情况。结果A、B组单侧乳腺切除时间分别为(77.18±9.2.)、(76.38±12.88)min,差异有统计学意义(P2..61±0.91)℃,低于B组(33.38±1.14)℃,差异亦有统计学意义(P2.(2.0%)、B组5例(17.2.),发生率差异有统计学意义(P<0.05)。其中,B组1例水疱破裂并感染,最终导致假体取出;其余患者均干预处理后恢复正常。结论R-NSM-IBR术中采用在乳房表面覆盖冰水冷却后纱布降温方法可有效降低热蒸汽损伤皮肤的风险。

关键词：机器人手术乳房重建皮肤热损伤

Analysis of the Effects of Different Synthesis and Processing Methods on Circular RNA Integrity,Protein Expression,and Removal of Immunogenic Impurities

在线全文

学校读者我要写书评

暂无评论

Journal of Clinical and Nursing Research 2024年第9期8卷 191-200页

作者： Shao Wang Tzuen Yih Saw Zebin Hong kuo Chieh Liao Haiwei Song Yue Wan Genome Institute of Singapore Agency for ScienceTechnology and Research138672 SingaporeSingapore Department of Biochemistry and Molecular Biology University of British ColumbiaVancouverBC V6T 1Z3Canada Institute of Molecular and Cell Biology Agency for ScienceTechnology and Research138673 SingaporeSingapore

Circular RNAs(circRNAs)are emerging as a promising alternative to messenger RNAs(mRNAs)in gene delivery applications due to their enhanced stability and *** circRNA-based therapeutic platforms requires efficient manufacturing of circRNA with broad ***,the permuted intron-exon(PIE)-based circRNA production commonly used to date involves complex RNA synthesis,circularization,precursor RNA digestion,and impurity removal steps that have limited practical *** co-transcriptional circularization could effectively streamline circRNA production,and both cellulose/phosphatase treatment and high-performance liquid chromatography(HPLC)have demonstrated their reliability in mRNA manufacturing,their potential effects on the quality,translation,and reactogenicity of circRNA remained to be fully ***,using circRNAs systematically manufactured through three independent workflows,we comprehensively examined the utilities of these RNA synthesis and processing methods in circRNA production by comparing the integrity,translation,and immunogenicity of their circRNA *** began by manufacturing a mNeonGreen(mNG)-encoding circRNA through these workflows and subsequently assessed circRNA integrity via E-gel EX *** expression was then monitored in HEK 2.3T,A549,and DC2.4 cells at 72.hours ***,we evaluated the immunogenicity of these circRNAs by measuring their interferon beta(IFN-β)induction in A549 cells at 4 hours *** HPLC purification over cellulose and phosphatase treatment resulted in 10-14%higher circRNA enrichment by reducing nicking associated with processing *** expression remained consistent across circRNAs from different workflows(P>0.05),demonstrating that co-transcriptional circularization produces circRNA with translation levels comparable to those obtained from the conventional PIE ***,both cellulose/phosphatase treatment

关键词： Nucleic acid therapeutics RNA manufacturing Circular RNA Gene delivery

考虑Hansbo渗流及变井阻的竖井地基非线性大应变固结分析

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

工程力学 2024年第9期41卷 144-154页

作者：李阔李传勋郭霄江苏大学土木工程与力学学院江苏镇江212013 浙江公路水运工程咨询有限责任公司浙江杭州310006

大量资料表明,软土中孔隙水渗流在低水力坡降时会偏离达西定律,同时高压缩性软土在外载作用下产生的较大应变致使经典的小应变固结理论不再适用,竖井地基中的软土大应变也必然导致排水体发生弯折、出现淤堵等不良排水状态从而影响竖井... 详细信息

大量资料表明,软土中孔隙水渗流在低水力坡降时会偏离达西定律,同时高压缩性软土在外载作用下产生的较大应变致使经典的小应变固结理论不再适用,竖井地基中的软土大应变也必然导致排水体发生弯折、出现淤堵等不良排水状态从而影响竖井的通水量。基于此,应用经典的Hansbo渗流定律描述软土中的渗流规律,采用随时间、深度变化的变井阻模型描述竖井在固结过程中通水量的变化,在Gibson大应变几何假定下建立可以考虑外荷载随时间变化的竖井地基大应变非线性固结模型,并给出其数值解答。通过与退化工况下已有的解答和工程实例开展对比分析,验证所建固结模型的可信性。对不同工况下的竖井地基大变形固结性状进行分析时发现:Hansbo渗流参数m和i1在合理取值范围内时其与达西渗流竖井地基固结度间的差异可高达10%,但当井径比小于13时,两者间的差异不到5%,此时可忽略土中存在的非达西渗流现象,一旦井径比超过13,竖井地基固结计算就有必要考虑土中的Hansbo渗流现象;变井阻导致竖井的通水量逐渐降低,在考虑土中Hansbo渗流后,变井阻与常井阻计算的竖井地基平均固结度间的差异最大达10%;竖井长度与竖井影响区半径之比(H/r_(e))达到12.5时,土中竖向渗流已影响甚微,且随着H/r_(e)的增大竖向渗流的影响会更小,此时可忽略不计。

关键词：岩土工程竖井地基数值解 Hansbo渗流变井阻大应变非线性固结

Longitudinal associations of cardiovascular health and vascular events with incident dementia

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

Stroke & Vascular Neurology 2024年第4期9卷 418-428,I0066-I0130页

作者： Ya-Nan Ou Kevin kuo Liu Yang Ya-Ru Zhang Shu-Yi Huang Shi-Dong Chen Yue-Ting Deng Yu Guo Rui-Qi Zhang Bang-Sheng Wu Lan Tan Qiang Dong Jian-Feng Feng Wei Cheng Jin-Tai Yu Department of Neurology Qingdao Municipal HospitalQingdao UniversityQingdaoShandongPeople's Republic of China Department of Neurology and National Center for Neurological Disorders Huashan HospitalState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceShanghai Medical CollegeFudan UniversityShanghaiPeople's Republic of China Institute of Science and Technology for Brain-inspired Intelligence Fudan UniversityShanghaiPeople's Republic of China Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence Fudan UniversityMinistry of EducationShanghaiPeople's Republic of China

Introduction Evidence supporting cardiovascular diseases could increase the risk of dementia remains fragmented.A comprehensive study to illuminate the distinctive associations across different dementia types is still *** study is sought to:(1)determine the clinical validity of Framingham General Cardiovascular Risk Score(FGCRS)for dementia assessment and(2.examine the associations between cardiovascular diseases and the risk of *** A total of 432.79 dementia-free individuals at baseline from UK Biobank were *** Cox proportional hazard models were used to investigate the prospective associations for FGCRS and a series of cardiovascular diseases with all-cause dementia(ACD)and its major components,Alzheimer’s disease(AD)and vascular dementia(VaD).Results During a median follow-up of 110.1 months,4711 individuals were diagnosed with *** was associated with increased risks across the dementia *** stratification analysis,high-risk groups have demonstrated the greatest dementia burdens,particularly to *** 74 traits,9 adverse associations,such as chronic ischaemic heart disease(ACD:HR=1.354;AD:HR=1.2.9;VaD:HR=1.768),atrioventricular block(ACD:HR=1.562.AD:HR=1.556;VaD:HR=2.069),heart failure(ACD:HR=1.639;AD:HR=1.543;VaD:HR=2.141)and hypotension(ACD:HR=2.912.AD:HR=2.361;VaD:HR=3.315)were *** distinctions were also found,with atrial fibrillation,cerebral infarction,and haemorrhage only associated with greater risks of ACD and *** By identifying distinctive associations between cardiovascular diseases and dementia,this study has established a comprehensive‘mapping’that may untangle the long-standing *** has demonstrated its predictivity beyond cardiovascular diseases burdens,suggesting potential opportunities for implantation.

关键词： cardiovascular diseases supporting

基于生成对抗网络的布里渊分布式光纤传感器降噪

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

光学学报 2024年第1期44卷 387-397页

作者：罗阔王宇瑶朱柏蓉余贶琭北京交通大学信息科学研究所北京100044 现代信息科学与网络技术北京市重点实验室北京100044 香港理工大学电子及信息工程系光子研究所中国香港999077

首先,利用自洽约束生成对抗网络(SCGAN)建模布里渊增益谱(BGS)中的真实噪声分布,生成噪声数据用于去噪卷积神经网络训练。通过对高斯噪声和SCGAN生成噪声进行直方图统计和幅度谱分析,证明了两种噪声的差异。然后,利用2.噪声分别训练3... 详细信息

首先,利用自洽约束生成对抗网络(SCGAN)建模布里渊增益谱(BGS)中的真实噪声分布,生成噪声数据用于去噪卷积神经网络训练。通过对高斯噪声和SCGAN生成噪声进行直方图统计和幅度谱分析,证明了两种噪声的差异。然后,利用2.噪声分别训练3种最新的去噪卷积神经网络,在不同温度、不同信噪比的实验数据上对比了各网络的性能。实验结果表明,所提方法能准确获取低信噪比BGS的布里渊频移,说明基于生成对抗网络的噪声提取方式能够有效地建模真实噪声,更好地训练有监督网络。

关键词：光纤光学布里渊分布式光纤传感图像去噪生成对抗网络自洽约束噪声建模

虚拟现实技术在孤独症谱系障碍儿童干预中的研究进展

在线全文

学校读者我要写书评

暂无评论

中国当代儿科杂志 2024年第4期26卷 414-419页

作者：郭乃绮(综述) 王瑜(审校) 上海交通大学医学院附属儿童医院上海市儿童医院儿童保健医学部康复科上海200062

孤独症谱系障碍(autism spectrum disorder,ASD)是儿童期神经发育障碍性疾病之一,目前治疗尚无特效方法,主要干预措施以教育训练和行为矫正为主。虚拟现实作为新兴技术,是一种以计算机为基础的环境模拟系统,通过融合多种来源信息实现交... 详细信息

孤独症谱系障碍(autism spectrum disorder,ASD)是儿童期神经发育障碍性疾病之一,目前治疗尚无特效方法,主要干预措施以教育训练和行为矫正为主。虚拟现实作为新兴技术,是一种以计算机为基础的环境模拟系统,通过融合多种来源信息实现交互式动态和沉浸式体验,近年逐渐被应用于ASD儿童干预训练。该文将综述虚拟现实在ASD儿童的情绪认知、社交能力、生活能力、运动能力、特殊恐惧方面的干预研究进展,为ASD干预训练拓展新方向。

关键词：孤独症谱系障碍虚拟现实干预儿童