检索结果-南通市图书馆

A novel electrospinning method for self-assembled tree-like fibrous scaffolds:Microenvironment-associated regulation of MSC behavior and bone regeneration

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 Materials Science & Technology 2022年第20期115卷 52-70页

作者： Jeong In kim ju Yeon kim Sung-Ho Kook Jeong-Chae Lee Cluster for Craniofacial Development and Regeneration Research Institute of Oral Biosciences and School of DentistryJeonbuk National UniversityJeonju 54896Republic of Korea Department of Bionanosystem Engineering Jeonbuk National UniversityJeonju 54896Republic of Korea Department of Bioactive Material Sciences Research Center of Bioactive MaterialsJeonbuk National UniversityJeonju 54896Republic of Korea

Numerous studies highlight advantages of electrospun scaffolds in bone tissue engineering,in which cellular behavior is tightly affected by fiber topographical cues of ***,the classic electrospinning setup limits a desired presentation of biomimetic fibrous microenvironments that sense mechanosignaling and regulate stem cell *** aims of this study were to fabricate advanced asspun scaffolds presenting tree-like microfiber/nanonet networks and to evaluate their regulatory potentials on behavior of human mesenchymal stem cells(h MSCs)and bone *** we developed a novel electrospinning setup that allowed the presentation of patterned Trunk microfibers(TMF)and/or branched nanonet fibers(BNn Fs)in biomimetic fibrous *** the cellular mechanisms,anisotropichierarchical topography of TMF controlled behavior of h MSCs through focal adhesion formation and Yesassociated protein(YAP)induction,whereas BNn F disturbed such mechanosensing responses in the *** fiber microenvironment-related expression and nuclear localization of YAP *** correlated with the potentials of as-spun scaffolds to enhance osteogenic differentiation of the h MSCs and alveolar bone defect healing in an animal ***,this study provides an advanced approach of the modified electrospinning setup for presentation of biomimetic fibrillar microenvironments in as-spun scaffolds along with their application in stem cell behavior regulation and regenerative tissue engineering.

关键词： Electrospinning Advanced biomimetic scaffolds Stem cell behavior Mechanosensing Bone tissue engineering

Cutoff characteristics of dielectric-filled circular holes embedded in dispersive plasmonic medium

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第10期7卷 904-908页

作者： Ki young kim Department of Physics National Cheng Kung University

The cutoff characteristics of dielectric-filled circular holes embedded in a dispersive plasmonic medium are investigated. Since two distinctive operating modes, surface plasmon polariton and circular waveguide modes, can exist in the slow and fast wave regions, respectively, the cutoff characteristics for each are separately investigated for linear and radial polarizations of the guided fields. As a result, the cutoff wavelengths for the linear and radial polarizations with very small subwavelength hole radii are found to be limited by the plasma resonance wavelength and plasma wavelength, which in turn are dependent and independent, respectively, of the dielectric constant of the dielectric filler material.

关键词： Circular waveguides Polarization Surface plasmon resonance

Robust fault detection of piecewise affine ARX systems

在线全文

学校读者我要写书评

暂无评论

Journal of Control and Decision 2020年第3期7卷 276-285页

作者： young-Man kim School of Engineering Liberty University1971 University Blvd.LynchburgVAUSA

In this paper,l1 regularisation-based robust fault detection technique for PWARX(PieceWise affine Auto Regressive eXogenous)systems is *** problem is formulated in convex optimisation form using l1 regularisation hence,global solution can be *** regularisation constant plays a key role for finding the number of *** MSE(mean square error)value between actual system and its model under no fault is used as a threshold for tracking dynamics change and detecting *** simplicity of turning only one parameter(regularisation constant)outstands this approach from *** proposed algorithm also shows the capability of separating the dynamics change from additive fault under *** illustration concludes this proposal by demonstrating its effectiveness.

关键词： Piecewise affine ARX fault detection regularisation convex optimisation sparsity

Effect of carrier gas species on the microstructure and compressive deformation behaviors of ultra-strong pure copper manufactured by cold spray additive manufacturing

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 Materials Science & Technology 2022年第2期97卷 264-271页

作者： young-Kyun kim Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea

Cold spray(CS)which has recently become a promising additive manufacturing(AM)technology,was used to fabricate ultra-strong pure *** addition,the effects of carrier gas species on the microstructural characteristics,mechanical properties and deformation mechanisms were systemically *** CSAM copper manufactured with N_(2) carrier gas reveals a heterogeneous bimodal microstructure consisting of ultra-fine grains at the particle interface and relatively coarse grains in inner *** He carrier gas,a homogeneous grain structure consisting of ultra-fine grains in most areas was *** tests showed that N_(2) and He carrier gasses enabled ultra-high yield strengths of 340 and415 MPa,*** values are comparable to severely plastic deformed copper,which has extremely low ductility and shape *** the other hand,both samples showed a strain-softening phenomenon that does not commonly occur at room *** deformation microstructures revealed that dynamic recovery(DRV)and dynamic recrystallization(DRX)phenomena were generated despite being deformed at room *** on the above findings,the overall deformation mechanisms according to the carrier gas species in the CSAM copper manufacturing process were ***,the work hardening and softening behaviors of CSAM Cu are predicted by using a constitutive equation.

关键词： Cold spray additive manufacturing Carrier gas Pure Cu Mechanical properties Deformation behavior

Stabilized sub-grain and nano carbides-driven 1.2 GPa grade ultra-strong CrMnFeCoNi high-entropy alloy additively manufactured by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： young-Kyun kim Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(kimS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Environmental Sound Event Detection in Wireless Acoustic Sensor Networks for Home Telemonitoring

在线全文

学校读者我要写书评

暂无评论

China Communications 2017年第9期14卷 1-10页

作者： Hyoung-Gook kim Jin young kim The Dept. of Electronics Convergence Engineering Kwangwoon University The Dept. of Electronics and Computer Engineering Chonnam National University

In this paper, we present an approach to improve the accuracy of environmental sound event detection in a wireless acoustic sensor network for home monitoring. Wireless acoustic sensor nodes can capture sounds in the home and simultaneously deliver them to a sink node for sound event detection. The proposed approach is mainly composed of three modules, including signal estimation, reliable sensor channel selection, and sound event detection. During signal estimation, lost packets are recovered to improve the signal quality. Next, reliable channels are selected using a multi-channel cross-correlation coefficient to improve the computational efficiency for distant sound event detection without sacrificing performance. Finally, the signals of the selected two channels are used for environmental sound event detection based on bidirectional gated recurrent neural networks using two-channel audio features. Experiments show that the proposed approach achieves superior performances compared to the baseline.

关键词： sound event detection wirelesssensor network gated recurrent neural net-work multichannel audio

Machine learning of metal-ceramic wettability

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2022年第1期8卷 195-203页

作者： So Yeon kim ju Li Department of Materials Science and Engineering and Department of Nuclear Science and Engineering assachusetts Institute of TechnologyCambridgeMA02139USA

The adhesion and wetting between metal and ceramic is a basic problem in materials science and *** example,past materials selection for metal-ceramic composites has relied on random trials and heuristics due to a limited understanding of their adhesion;the large chemical/structural variability that such interfaces can have hinders the identification of the governing *** based on literature data,we have developed a database with~1,000 experimentally measured wetting angles at different temperatures and atmospheric conditions,and come up with a model for the wettability of ionocovalent ceramics(ICs)by metals using a machine learning(ML)*** random forest model uses the testing temperature and~40 features generated based on the chemical compositions of the metal and the ceramic as predictors and exhibits strong predictive power with an R^(2) of~***,this model and the featurization code are integrated into a single computational pipeline to enable(1)predicting metal-IC wettability of interest and(2)high-throughput searching of ICs with the desired wettability by certain metals in the entire Inorganic Crystallographic Structure *** a demonstration of this pipeline,the wettability of a Li-ion and electron insulator(LEI),CaO,by molten Li is estimated and compared with ab initio molecular dynamics simulation *** ML pipeline can serve as a practical tool for methodical design of materials in systems where certain metalceramic wettability is desired.

关键词： Metal-ceramic wettability Wetting angle Machine learning High-throughput screening Solid-state batteries

Effects of compressive stress on the nonlinear electromechanical behavior of ferroelectric ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第1期49卷 29-37页

作者： LEE jung-ju kim Hyun Cheol Department of Mechanical Engineering KAIST Taejon 305-701 Korea

The effects of compressive stress parallel and perpendicular to the polar axis of PZT ceramics on the nonlinear electromechanical behavior of the materials has been experimentally studied. A domain-switching model that divides each 180° switching to two successive 90° switching is proposed to explain these effects. In the case of stress parallel to the polar axis, domain switching in the ceramics is approximately axisymmetric and can be simulated by an analytical model. While in the case of stress perpendicular to the polar axis, domain switching is three-dimensional and cannot be simplified. The simulated re-sults that match the experiments well show the validity of the proposed domain-switching model.

关键词： ferroelectric ceramics, domain switching, electromechanical, PZT.

Clinical implications of fatty pancreas:Correlations between fatty pancreas and metabolic syndrome

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第15期15卷 1869-1875页

作者： jun Seok Lee Sang Heum kim Dae Won jun Jee Hye Han Eun Chul Jang Ji young Park Byung Kwan Son Seong Hwan kim Yoon ju Jo young Sook Park Yong Soo kim Department of Internal Medicine Eulji University School of Medicine Department of Radiology Eulji University School of Medicine Department of Family Medicine Eulji University School of Medicine Department of Occupational and Environmental Medicine College of MedicineSoonchunhyang University Department of Radiology Hanyang University School of Medicine

AIM:To investigate the clinical implications of lipid deposition in the pancreas(fatty pancreas). METHODS:The subjects of this study were 293 patients who had undergone abdominal computed tomography(CT)and *** pancreas was diagnosed by sonographic findings and subdivided into mild,moderate,and severe fatty pancreas groups comparing to the retroperitoneal fat echogenicity. RESULTS:Fatty pancreas was associated with higher levels for visceral fat,waist circumference,aspartate aminotransferase(AST),alanine aminotransferase (ALT),total cholesterol,triglyceride,high density lipoprotein,free fatty acid,γ-GTP,insulin,and the homeostasis model assessment of insulin resistance (HOMA-IR)than the control group(Pjustment for age,body mass index,and lipid *** incidence of metabolic syndrome in the fatty pancreas group was significantly higher than in the control group,and the numbers of metabolic syndrome parameters were significantly higher in the fatty pancreas group(P<0.05).CONCLUSION:Sonographic fatty pancrease showed higher insulin resistance,visceral fat area,triglyceride, and ALT levels than normal *** pancreas also showed a strong correlation with metabolic syndrome.

关键词： Fatty pancreas Metabolic syndrome Insulin resistance