检索结果-南通市图书馆

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第3期12卷 841-872页

作者： Jong Un Lee Hyun Ji kim sang-Cheol Jin Ye Jin kim Young Min kim Bong Sun You Jun Ho bae Sung Hyuk Park Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Missile Research Institute Agency for Defense DevelopmentDaejeon 34060Republic of Korea

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials *** alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical *** main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening *** enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in ***,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

关键词： SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties Extrudability.

Negative Stiffness Mechanism on An Asymmetric Wave Energy Converter by Using A Weakly Nonlinear Potential Model

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 689-700页

作者： Sunny Kumar POGULURI Dongeun kim Yoon Hyeok bae Department of Ocean Engineering IIT MadrasChennaiIndia Multidisciplinary Graduate School Program for Wind Energy Jeju National UniversityJejuRepublic of Korea Mechanical and System Design Engineering Hongik UniversitySeoulRepublic of Korea

Salter's duck,an asymmetrical wave energy converter(WEC)device,showed high efficiency in extracting energy from 2D regular waves in the past;yet,challenges remain for fluctuating wave *** can potentially be addressed by adopting a negative stiffness mechanism(NSM)in WEC devices to enhance system efficiency,even in highly nonlinear and steep 3D waves.A weakly nonlinear model was developed which incorporated a nonlinear restoring moment and NSM into the linear formulations and was applied to an asymmetric WEC using a time domain potential flow *** model was initially validated by comparing it with published experimental and numerical computational fluid dynamics *** current results were in good agreement with the published *** was found that the energy extraction increased in the range of 6%to 17%during the evaluation of the effectiveness of the NSM in regular *** irregular wave conditions,specifically at the design wave conditions for the selected test site,the energy extraction increased by 2.4%,with annual energy production increments of approximately *** findings highlight the potential of NSM in enhancing the performance of asymmetric WEC devices,indicating more efficient energy extraction under various wave conditions.

关键词： asymmetric wave energy converter negative stiffness mechanism weakly nonlinear potential flow power

Self-supported VO_(2)on polydopamine-derived pyroprotein-based fibers for ultrastable and flexible aqueous zinc-ion batteries

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第7期6卷 1-13页

作者： Jeong Seok Yeon Sul Ki Park Shinik kim Santosh VMohite Won Il kim Gun Jang Hyun-Seok Jang Jiyoung bae sang Moon Lee Won GHong Byung Hoon kim Yeonho kim Ho Seok Park School of Chemical Engineering College of EngineeringSungkyunkwan UniversityGyeonggi-doRepublic of Korea Department of Engineering University of CambridgeCambridgeUK Department of Applied Chemistry Konkuk UniversityChungjuRepublic of Korea Department of Chemistry Ulsan National Institute of Science and Technology(UNIST)College of Natural SciencesUlsanRepublic of Korea Department of Physics Incheon National UniversityIncheonRepublic of Korea Intelligent Sensor Convergence Research Center Incheon National UniversityIncheonRepublic of Korea Institute of Basic Science Incheon National UniversityIncheonRepublic of Korea Division of Material Analysis and Research Korea Basic Science InstituteDaejeonRepublic of Korea

A conventional electrode composite for rechargeable zinc-ion batteries(ZIBs)includes a binder for strong adhesion between the electrode material and the current ***,the introduction of a binder leads to electrochemical inactivity and low electrical conductivity,resulting in the decay of the capacity and a low rate *** present a binder-and conducting agent-free VO_(2)composite electrode using in situ polymerization of dopamine on a flexible current collector of pyroprotein-based *** as-fabricated composite electrode was used as a substrate for the direct growth of VO_(2)as a self-supported form on polydopamine-derived pyroprotein-based fibers(pp-fibers@VO_(2)(B)).It has a high conductivity and flexible nature as a current collector and moderate binding without conventional binders and conducting agents for the VO_(2)(B)*** addition,their electrochemical mechanism was *** energy storage is induced by Zn^(2+)/H^(+)coinsertion during discharging,which can be confirmed by the lattice expansion,the formation of by-products including Zn_(x)(OTf)_(y)(OH)_(2x−y)·nH_(2)O,and the reduction of V^(4+)to V^(3+).Furthermore,the assembled Zn//pp-fibers@VO_(2)(B)pouch cells have excellent flexibility and stable electrochemical performance under various bending states,showing application possibilities for portable and wearable power sources.

关键词： aqueous battery binder free conducting agent‐free flexible electrode zinc‐ion battery

YOLO-Based Damage Detection with StyleGAN3 Data Augmentation for Parcel Information-Recognition System

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 195-215页

作者： Seolhee kim sang-Duck Lee Department of Electrical and Computer Engineering Sungkyunkwan UniversitySuwon16419Republic of Korea Logistics System Research Division Korea Railroad Research InstituteUiwang16105Republic of Korea

Damage to parcels reduces customer satisfactionwith delivery services and increases return-logistics *** can be prevented by detecting and addressing the damage before the parcels reach the ***,various studies have been conducted on deep learning techniques related to the detection of parcel *** study proposes a deep learning-based damage detectionmethod for various types of *** is intended to be part of a parcel information-recognition systemthat identifies the volume and shipping information of parcels,and determines whether they are damaged;this method is intended for use in the actual parcel-transportation *** this purpose,1)the study acquired image data in an environment simulating the actual parcel-transportation process,and 2)the training dataset was expanded based on StyleGAN3 with adaptive discriminator ***,3)a preliminary distinction was made between the appearance of parcels and their damage status to enhance the performance of the parcel damage detection model and analyze the causes of parcel ***,using the dataset constructed based on the proposed method,a damage type detection model was trained,and its mean average precision was *** model can improve customer satisfaction and reduce return costs for parcel delivery companies.

关键词： Parcel delivery service damage detection damage classification data augmentation generative adversarial network

Weighted Forwarding in Graph Convolution Networks for Recommendation Information Systems

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2期78卷 1897-1914页

作者： sang-min Lee Namgi kim Department of Computer Science Kyonggi UniversitySuwonKorea

Recommendation Information Systems(RIS)are pivotal in helping users in swiftly locating desired content from the vast amount of information available on the *** Convolution Network(GCN)algorithms have been employed to implement the RIS ***,the GCN algorithm faces limitations in terms of performance enhancement owing to the due to the embedding value-vanishing problem that occurs during the learning *** address this issue,we propose a Weighted Forwarding method using the GCN(WF-GCN)*** proposed method involves multiplying the embedding results with different weights for each hop layer during graph *** applying the WF-GCN algorithm,which adjusts weights for each hop layer before forwarding to the next,nodes with many neighbors achieve higher embedding *** approach facilitates the learning of more hop layers within the GCN *** efficacy of the WF-GCN was demonstrated through its application to various *** the MovieLens dataset,the implementation of WF-GCN in LightGCN resulted in significant performance improvements,with recall and NDCG increasing by up to+163.64%and+132.04%,***,in the *** dataset,LightGCN using WF-GCN enhanced with WF-GCN showed substantial improvements,with the recall and NDCG metrics rising by up to+174.40%and+169.95%,***,the application of WF-GCN to Self-supervised Graph Learning(SGL)and Simple Graph Contrastive Learning(SimGCL)also demonstrated notable enhancements in both recall and NDCG across these datasets.

关键词： Deep learning graph neural network graph convolution network graph convolution network model learning method recommender information systems

Integration of earth-abundant cocatalysts for high-performance photoelectrochemical energy conversion

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 Energy Chemistry 2024年第1期88卷 336-355,I0008页

作者： Joonhee Ma sang Hyun Ahn Soo Young kim Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea School of Chemical Engineering and Materials Science Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Republic of Korea

Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and *** utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added ***,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical ***,significant research has been conducted to improve the overall conversion efficiency of PEC *** particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy *** review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) *** main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/***,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based *** addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with ***,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.

关键词： Solar energy Photo-electrochemical Water splitting CO_(2)reduction Cocatalysts

Wearable Triboelectric Nanogenerators Based on Printed Polyvinylidene Fluoride Films Incorporated with Cobalt-Based Metal-Organic Framework for Self-Powered Mobile Electronics

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第4期7卷 396-403页

作者： Myeong-Hyeon kim sang-Joon Park Tae-Jun Ha Department of Electronic Materials Engineering Kwangwoon University

In this study,wearable triboelectric nanogenerators comprising bar-printed polyvinylidene fluoride (PVDF) films incorporated with cobalt-based metalorganic framework (Co-MOF) were *** enhanced output performance of the TENCs was attributed to the phase transition of PVDF from α-crystals to β-crystals,as facilitated by the incorporation of the MOF.

关键词： bar printing phase transition polyvinylidene fluoride incorporated with cobalt-based metal–organic framework self-powered mobile electronics wearable triboelectric nanogenerators

Real-world utility of serological tests in patients with suspected scrub typhus in the Republic of Korea:A single-center,retrospective,observational study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2024年第6期17卷 273-280,I0004,I0005页

作者： Seulki kim A Reum kim Seungjin Lim Su Jin Lee Moonsuk bae Division of Infectious Diseases Department of Internal MedicinePusan National University Yangsan HospitalYangsanRepublic of Korea Research Institute for Convergence of Biomedical Science and Technology Pusan National University Yangsan HospitalYangsanRepublic of Korea Department of Internal Medicine Pusan National University School of MedicineBusanRepublic of Korea

Objective:Serological tests are widely used for scrub typhus diagnosis;however,their limitations are *** study aims to assess their practical value in clinical ***:We analyzed the data of adult patients with suspected scrub typhus who visited a tertiary care hospital in the Republic of Korea from September to December from 2019 to *** included patients had an acute fever and at least one of the following ten secondary findings:myalgia,skin rash,eschar,headache,thrombocytopenia,increased liver enzyme levels,lymphadenopathy,hepatomegaly,splenomegaly,and pleural *** diagnoses were grouped as scrub typhus or other diseases by two infectious disease ***:Among 136 patients who met the eligibility criteria,109 had scrub typhus and 27 had different *** and paired total antibodies using immunofluorescence assay(IFA),and total antibodies using immunochromatography-based rapid diagnostic testing(ICT)were measured in 98%,22%,and 75%of all patients,*** using paired samples for scrub typhus was established at a median of 11[interquartile range(IQR)10-16]days following the first *** the 82 admitted patients,the median admission time was 9(IQR 7-13)*** to IFA,58(55%)patients with scrub typhus had total immunoglobulin titers≥1:320,while 23(85%)patients with other disease had titers<1:*** ICT results were observed in 64(74%)patients with scrub typhus and 10(67%)patients with other diseases showed negative ICT ***:Serological testing for scrub typhus is currently insufficient for decision-making in clinical practice.

关键词： Scrub typhus Serological test Immunofluorescence assay Immunochromatography Rapid detecting test

Surgical Repair of Ventricular Septal Defect in Neonates: Indications and Outcomes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Congenital Heart Disease 2024年第1期19卷 69-83页

作者： Jae Hong Lee Sungkyu Cho Jae Gun Kwak Hye Won Kwon Woong-Han kim Mi Kyoung Song sang-Yun Lee Gi Beom kim Eun Jung bae Department of Thoracic and Cardiovascular Surgery Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan HospitalYangsanKorea Department of Thoracic and Cardiovascular Surgery Seoul National University Children’s HospitalSeoulKorea Department of Pediatrics Seoul National University Children’s HospitalSeoulKorea

Background:The optimal surgical timing and clinical outcomes of ventricular septal defect(VSD)closure in neo-nates remain *** aimed to evaluate the clinical outcomes of VSD closure in neonates(age≤30 days).Methods:We retrospectively reviewed 50 consecutive neonates who underwent VSD closure for isolated VSDs between August 2003 and June *** for the procedure included congestive heart failure/failure to thrive and pulmonary *** adverse events(MAEs)were deﬁned as the composite of all-cause mortality,reoperation,persistent atrioventricular block,and signiﬁcant(≥grade 2)valvular ***:The median age and body weight at operation were 26.0 days(interquartile range[IQR],18.8–28.3)and 3.7 kg(IQR,3.3–4.2),*** median follow-up duration was 110.4 months(IQR,56.8–165.0).Seven patients required preoperative respiratory support,andﬁve had signiﬁcant(≥grade 2)preoperative valvular *** early mortality occurred due to irreversible cardiogenic shock;no late mortality was *** reopera-tion was due to hemodynamically signiﬁcant residual VSD at 103.8 months *** overall survival,freedom from reoperation,and freedom from MAE at 15-years were 98.0%,96.3%,and 94.4%,***-operative mechanical ventilation was associated with a longer duration of postoperative mechanical ventilation(p<0.001)and a longer length of intensive care unit stay(p<0.001).Conclusions:VSD closure with favorable outcomes without morbidities is feasible even in ***,neonates requiring preoperative respiratory support may require careful postoperative management considering the long-term postoperative ***,surgical VSD closure might be indicated earlier in neonates with respiratory compromise.

关键词： Ventricular septal defect neonate early surgery neonatal surgery