检索结果-南通市图书馆

维普期刊数据库

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by.cry.tal plasticity.finite element method

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： y.B.Zhang S.J.Song F.Liu State Key.Laboratory.of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analy.ical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension cry.tal plasticity.finite element(3. CPFE)simulations,co-deformation and instability.of hetero-phase interface in different material sy.tems were herein studied for poly.ry.talline metal matrix composites(MMCs).Local stress and strain fields in two ty.es of 3.ay.r MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability.can be observed in the fcc/bcc sy.tems than in the fcc/fcc sy.tems upon refining to metallic nanolay.red composites(MNCs).By.detailed analy.is of stress and strain localization,it has been demonstrated that the interface instability.is alway. accompanied by.high-stress concentration,i.e.,thermody.amic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermody.amic driving forceG and the kinetic energy.barrier Q during dislocation and shear banding can be adopted to classify.the deformation modes,following the so-called thermo-kinetic *** by.inserting a high density.of high-energy.interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently.suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by.a couple of thermody.amics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially.designing MNCs.

关键词： Thermody.amics and kinetics Phy.ics-based constitutive modeling Hetero-phase interface Cry.tal plasticity.finite element

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

面向中文病历的实体关系抽取模型研究

现代情报 2024年

作者：单涛许鑫王园梦王宇翱景慎旗叶继元郭永安 1.南京大学信息管理学院 2.江苏省人民医院 3.南京邮电大学通信与信息工程学院南京大学信息管理学院南京邮电大学通信与信息工程学院江苏省人民医院

[目的/意义] 关系抽取是电子病历处理的核心组成部分，对于提高电子病历处理的准确性和效率至关重要。为解决中文电子病历关系抽取中实体冗余、实体词嵌套和实体重叠问题，提高医疗信息抽取效率，提出了一种新型的中文病历关系抽取模型... 详细信息

[目的/意义] 关系抽取是电子病历处理的核心组成部分，对于提高电子病历处理的准确性和效率至关重要。为解决中文电子病历关系抽取中实体冗余、实体词嵌套和实体重叠问题，提高医疗信息抽取效率，提出了一种新型的中文病历关系抽取模型。[方法/过程]将关系抽取任务分解关系优先解码器、全局实体提取和主体—客体对齐三部分。首先通过解码器预测和过滤关系，并基于预测的关系限制实体提取；其次采用关系特定的注意机制和全局指针网络，有效处理信息重叠和主体/客体嵌套问题；最后引入实体对应矩阵将主体、客体及其关系对齐为三元组。[结果/结论] 分别在CMeIE中文病历数据集和DiaKG真实糖尿病中文数据集上进行综合实验并与6种常用模型进行了对比分析，发现本文模型在数据集CMeIE和DiaKG上的F1值较主流模型CasRel分别提升了6.6%和5.8%。研究结果表明，本文模型可有效解决中文病历复杂性带来的实体嵌套和实体重叠问题，对医疗信息提取和数据处理流程具有良好价值。

关键词：关系抽取中文病历实体嵌套实体重叠注意力机制全局指针

Optimization of chemistry.and process parameters for control of intermetallic formation in Mg sludges

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloy. 2024年第4期12卷 1431-1448页

作者： y.Fu G.G.Wang A.Hu y.Li K.B.Thacker J.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada Global Technology.Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very.important ***,very.often it is overlooked by.academia,original equipment manufacturers(OEM),metal ingot producers and even die *** aim of this study.was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry.and process *** Al8Mn5 intermetallic particles were identified by.the microstructure analy.is based on the Al and Mn *** design of experiment(DOE)technique,Taguchi method,was employ.d to minimize the intermetallic formation in the sludge of Mg alloy. with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding *** sludge y.eld(Sy.and intermetallic size(IS)was selected as two *** optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 3. mins for the holding time,*** best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,63.℃ for the holding temperature and holding at 60 mins for the holding time,*** groups of sludge factors,Chemical Sludge(CSF),Phy.ical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge y.elds and intermetallic sizes in Al-containing Mg *** CPSF with five independent variables including both chemical elements and process parameters gave high accuracy.in prediction,as the prediction of the PSF with only.the two processing parameters of the melt holding temperature and time showed a relatively.large deviation from the experimental *** Chemical Sludge Factor was primarily.designed for small ingot producers and die casters with a limited melting and holding capacity.of which process parameters could be fixed *** Phy.ical Sludge Factor could be used f

关键词： Magnesium sludge Al-Mn intermetallic Optimization Taguchi method Sludge factor Chemical composition Process parameter

维普期刊数据库

全关节镜下弹性固定Latarjet手术治疗严重骨缺损的前向肩关节不稳研究

在线全文

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

作者：韩大伟应立沙林林惠宇应鲤蔚张庆国梁军波周晓波 1.浙江省台州医院运动医学科 2.浙江省台州医院骨科康复科 3.浙江省台州医院骨科浙江省台州医院运动医学科浙江省台州医院骨科康复科浙江省台州医院骨科

目的评估全关节镜下弹性固定Latarjet手术治疗严重骨缺损的前向肩关节不稳的疗效。方法回顾分析2020年6月—2023.2月采用全关节镜下弹性固定Latarjet术治疗的15例符合选择标准的严重骨缺损前向肩关节不稳患者临床资料。其中男11例，女... 详细信息

目的评估全关节镜下弹性固定Latarjet手术治疗严重骨缺损的前向肩关节不稳的疗效。方法回顾分析2020年6月—2023.2月采用全关节镜下弹性固定Latarjet术治疗的15例符合选择标准的严重骨缺损前向肩关节不稳患者临床资料。其中男11例，女4例；年龄20～54岁，平均3..1岁。三维CT示关节盂骨缺损16.3.～3..2%，平均24.4%。肩关节脱位3.8次，平均4.2次。病程6～21个月，平均10.6个月。记录手术时间、术中出血量；手术前后采用疼痛视觉模拟评分（VAS）评估疼痛缓解情况，Rowe评分、Walch-Duplay.分、美国肩关节和肘关节外科医生（ASES）评分评价肩关节功能恢复情况；评估肩关节各向活动度（range of motion,ROM），包括主动前屈、体侧外旋、外展90°外旋和内旋。术后6个月和末次随访时行三维CT检查，观察移植骨块吸收情况、骨块与关节盂位置以及骨块愈合情况。结果所有患者手术均顺利完成，手术时间85～195 min，平均123.0 min；术中出血量20～75 mL，平均26.5 mL。15例患者均获随访，随访时间13.3.个月，平均18.7个月。随访期间患者均未出现肩关节感染、关节僵硬、血管神经损伤等严重并发症。1例术后3.月出现移植骨部分吸收、骨不连，但末次随访时肩关节疼痛等较术前改善，未发生肩关节再脱位等情况；其余患者未发现明显骨块骨折、肩关节脱位等情况。术后6个月随访时骨块均已愈合。末次随访时，患者VAS评分、Rowe评分、WalchDuplay.分和ASES评分均较术前改善，差异有统计学意义（P0.05）。结论全关节镜下弹性固定Latarjet手术治疗严重骨缺损的前向肩关节不稳，术后临床功能改善明显，影像学提示移植骨块位置满意。

关键词：肩关节脱位关节镜喙突改良Latarjet手术

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

北斗卫星B2信号数字预失真补偿方法研究

系统工程与电子技术 2024年

作者：刘瑞贺成艳张小贞白燕 1.中国科学院国家授时中心 2.中国科学院大学天文与空间科学学院 3.西北工业大学电子信息学院西北工业大学电子信息学院中国科学院大学天文与空间科学学院中国科学院国家授时中心

针对北斗星上信号发射通道中高功放和滤波器引起的导航信号非线性失真问题，本文提出了间接学习结构的数字预失真用以补偿导航信号产生的非线性失真。通过采用带宽最大的非对称恒包络二进制偏移载波（Asy.metric Constant Envelope Bina... 详细信息

针对北斗星上信号发射通道中高功放和滤波器引起的导航信号非线性失真问题，本文提出了间接学习结构的数字预失真用以补偿导航信号产生的非线性失真。通过采用带宽最大的非对称恒包络二进制偏移载波（Asy.metric Constant Envelope Binary.Offset Carrier， ACE-BOC）调制的北斗B2信号，验证数字预失真对补偿导航信号非线性失真的有效性及可行性，并从调制星座、功率谱、相关函数以及S曲线过零点偏差等信号评估指标对数字预失真处理前后的信号进行对比分析。实验结果表明数字预失真可以有效抑制20dB的带外功率损失，相关损失可由0.7dB下降到0.009dB以及S曲线过零点偏差由0.88ns下降到0.0029ns。

关键词：北斗卫星导航系统 B2信号高功率放大器数字预失真信号质量评估

Mechanisms behind the environmental sensitivity.of carbon fiber reinforced poly.etrafluoroethy.ene(PTFE)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第5期12卷 997-1015页

作者： Pontus JOHANSSON P.MARKLUND M.BJORLING y.SHI Division of Machine Element LuleåUniversity of TechnologyLuleåSE-97187Sweden

Carbon fiber reinforced poly.etrafluoroethy.ene (CF/PTFE) composites are known for their exceptional tribological performance when sliding against steel or cast iron in inert gas environments. Compared to experiments in humid air, about an order of magnitude lower wear rate and several times lower coefficient of friction have been reported for tests conducted in dry.nitrogen and hy.rogen. Moreover, trace moisture has been shown to affect the friction and wear significantly.of this tribosy.tem, although a possible effect of oxy.en cannot be ruled out due to uncertainties regarding the oxy.en concentrations. While several studies have pointed out the environmental sensitivity.of CF/PTFE, the understanding of the underly.ng mechanisms are very.limited. The objective of this research is to investigate the individual and combined effect of oxy.en and moisture on the tribological behavior of CF/PTFE sliding against steel. Additionally. this study.aims to elucidate the underly.ng mechanisms that govern the environmental sensitivity.of the sy.tem. Climate-controlled three-pin-on-disc experiments were conducted in nitrogen atmospheres at various concentrations of oxy.en and moisture. The tribological results clearly.demonstrate that both moisture and oxy.en contribute to increased friction and wear. However, the adverse effect was much more pronounced for oxy.en than moisture. A qualitative method was developed to estimate the tribofilm coverage on the CF/PTFE surface. Results showed strong correlation between high coverage of strongly.adhered tribofilm and low wear rate. Moreover, a loosely.adhered tribofilm was observed on top of the CF/PTFE surface in presence of moisture. FTIR analy.is indicated that the loosely.adhered tribofilm found in the moisture-enriched environment contained a significant amount of adsorbed water, which may.explain the lower coefficient of friction in presence of moisture compared to oxy.en. The adsorbed water in the loosely.adhered tribofilm coul

关键词： poly.er composite tribofilm tribochemistry atmosphere

Focal Nodular Hy.erplasia: A Comprehensive Review with a Particular Focus on Pathogenesis and Complications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Clinical and Translational Hepatology 2024年第2期12卷 182-190页

作者： Jaimy.Villavicencio Kim George y.Wu Division of Gastroenterology.Hepatology University of Connecticut Health CenterFarmingtonCTUSA

Focal nodular hy.erplasia is a benign tumor of the liver that is often found incidentally.with *** purpose of this review is to discuss the pathophy.iology.rare complications that can occur due to these lesions,and management options.A literature review was performed on clinical trials and case reports involving focal nodular hy.erplasia complications and management of these,as well as the proposed pathogenesis underly.ng these *** exposure to oral contraceptive pills and endogenous hormones have been thought to play.a role in the development of these lesions,this has not been *** recently.they.are thought to arise as a consequence of a vascular anomaly.causing alterations in the expression of angiopoietin *** are rare,but previous cases have reported associated pain,rupture and compression of nearby.structures(hepatic vein,stomach,biliary.sy.tem).Resection of focal nodular hy.erplasia is not usually.***,if there is associated pain with no other identifiable cause or presence of a large or growing lesion with risk of causing a complication,then surgical resection,radiofrequency.ablation or arterial embolization should be considered.

关键词： Focal nodular hy.erplasia Oral contraceptives Liver lesion

Evaluation of Industrial IoT Service Providers with TOPSIS Based on Circular Intuitionistic Fuzzy.Sets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第7期80卷 715-746页

作者： Elif Çalo˘glu Büy.kselçuk Industrial Engineering Department Fenerbahçe University˙Istanbul34758Turkey

Industrial Internet of Things(IIoT)service providers have become increasingly.important in the manufacturing industry.due to their ability.to gather and process vast amounts of data from connected devices,enabling manufacturers to improve operational efficiency.reduce costs,and enhance product *** platforms provide manufacturers with real-time visibility.into their production processes and supply.chains,allowing them to optimize operations and make informed *** addition,IIoT service providers can help manufacturers create new revenue streams through the development of innovative products and services and enable them to leverage the benefits of emerging technologies such as Artificial Intelligence(AI)and machine ***,the implementation of IIoT platforms in the manufacturing industry.is crucial for companies seeking to remain competitive and meet the ever-increasing demands of customers in the digital *** this study.the evaluation criteria to be considered in the selection of IIoT service provider in small andmedium-sized(SME)manufacturing enterprises will be determined and IIoT service providers alternatives will be evaluated using the technique for order preference by.similarity.to an ideal solution(TOPSIS)method based on circular intuitionistic fuzzy.*** on the assessments conducted in accordance with the literature review and expert consultations,a set of 8 selection criteria has been *** criteria encompass industry.expertise,customer support,flexibility.and scalability.security.cost-effectiveness,reliability.data analy.ics,as well as compatibility.and *** evaluating these criteria,it was observed that the security.criterion holds the highest significance,succeeded by.cost-effectiveness,data analy.ics,flexibility.and scalability.reliability.and customer support criteria,in descending order of *** the evaluation of seven distinct alternatives against these criteria,it was deduced tha

关键词： IIoT manufacturing TOPSIS circular intuitionistic fuzzy.sets

国家发展改革委国家数据局财政部自然资源部关于深化智慧城市发展推进城市全域数字化转型的指导意见

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国产经 2024年第10期 12-17页

作者： 1.国家发展改革委 2.国家数据局 3.财政部 4.自然资源部国家发展改革委国家数据局财政部自然资源部

各省列、市、自新治疆区、生直产辖建市设及兵计团发划展单改革委、数据管理部门、财政厅（局）、自然资源主管部门：城市是推进数字中国建设的综合载体，推进城市数字化转型、智慧化发展，是面向未来构筑城市竞争新优势的关键之举，也...

各省列、市、自新治疆区、生直产辖建市设及兵计团发划展单改革委、数据管理部门、财政厅（局）、自然资源主管部门：城市是推进数字中国建设的综合载体，推进城市数字化转型、智慧化发展，是面向未来构筑城市竞争新优势的关键之举，也是推动城市治理体系和治理能力现代化的必然要求。为深入贯彻落实党中央、国务院关于数字中国建设的决策部署，以数据融通、开发利用贯穿城市全域数字化转型建设始终，更好服务城市高质量发展、高效能治理、高品质生活，支撑发展新质生产力，推进中国式现代化城市建设，特制定本意见。

关键词：