检索结果-南通市图书馆

Particle morphology control for spherical powder fabrication using the ball milling process with DEM simulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 41-50页

作者： Battsetseg Jargalsaikhan Khulan Uranchimeg Amgalan Bor kyung sung kim Heekyu Choi Research Institute of Future Convergence Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea Graduate School of Material Science Engineering Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea Department of Chemical and Biological Engineering School of Engineering and Applied SciencesNational University of MongoliaUlaanbaatar 14200Mongolia Department of Mechatronics Convergence Engineering College of Future ConvergenceChangwon National UniversityChangwonGyoungnam 641-773Republic of Korea Graduate School of Convergence on Culture Technology Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea

Characteristics of spherical particles on copper powder and changing sizes were studied in a ball mill under various experimental conditions,such as different ball diameters,high rotation speeds,and milling times,using a discrete element method(DEM)*** experiment has investigated the characteristics of spherical particle morphology evolution involved in the mechanical alloying of copper *** morphological evolution of the copper particle was analyzed using scanning electron microscopy(SEM).A spherical copper particle was shown with a roundness value using imageJ *** DEM was used to simulate the ball motion in a planetary ball mill,and the impact energy and shear energy generated during the collision were analyzed to estimate the contact number between the ball and the ball ***,as the size of the ball decreased,the number of ball-to-ball and ball-to-wall contacts increased accordingly,and the spherical shape of the copper powder changed.

关键词： Planetary ball mill DEM simulation Spherical particle morphology Copper powder Ball diameter

Unusual presentation of granulomatosis with polyangiitis causing periaortitis and consequent subclavian steal syndrome:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第6期9卷 1433-1438页

作者： Uiju Cho sung-kyung kim Jeong Min Ko Jinyoung Yoo Department of Pathology St.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591South Korea Department of Internal Medicine St.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591South Korea Department of Radiology St.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591South Korea Department of Hospital Pathology St.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591South Korea

BACKGROUND Granulomatosis with polyangiitis(GPA)is a rare autoimmune disease that involves small-to-medium-sized vessels and forms necrotizing vasculitis with granulomatous *** formation of a large vessel lesion in GPA patients has been scarcely reported,and it can cause confusion in the *** SUMMARY A 27-year-old man presented with mild left-sided pleuritic chest pain that started one year *** imaging study revealed up to 2.5 cm-sized two irregular nodular consolidation nodule in the left lower *** nodules showed central ***,there was a periaortic mass occluding the branching porting of the subclavian *** had positive anti-neutrophil cytoplasmic antibodies(ANCAs),but myeloperoxidase-ANCAs and proteinase 3-ANCAs were *** patient also developed symptoms of subclavian vein syndrome during the *** resection of the lung revealed necrotizing vasculitis,destructive parenchymal abscess and surrounding granuloma,and therefore diagnosed of *** patient started on methotrexate and steroid therapy with a relief of *** Here,we present an unusual manifestation of GPA with periaortitis and consequent subclavian steal syndrome,which has never been previously *** case alerts us that we should include GPA in the differential diagnosis of large vessel vasculitis as well as subclavian steal syndrome.

关键词： Granulomatosis with polyangiitides Wegener granulomatosis Systemic vasculitis Subclavian steal syndrome Periaortitis Case report

Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram kim Myeong‑Chang sung Gwang‑Hee Lee Byoungjoon Hwang Sojung Seo Ji‑Hun Seo Dong‑Wan kim Department of Materials Science and Engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical Engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

Regulation of sleep by astrocytes in the hypothalamic ventrolateral preoptic nucleus

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1098-1100页

作者： Jae-Hong kim Ruqayya Afridi Il-sung Jang Maan Gee Lee Kyoungho Suk Brain Korea 21 four KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of DentistryKyungpook National UniversityDaeguRepublic of Korea Brain Science&Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea

Astrocytes are functionally dynamic cells that support neurons in multiple ways throughout an organism’s *** astrocytic regulation of neuronal activity has been increasingly recognized in recent *** are now recognized as playing a more complex role than mere bystanders in the central nervous ***,their role in regulating the sleep neurocircuitry is not well *** this perspective,we highlight the role of astrocytes in sleep modulation,with a particular focus on regulatory mechanisms related to the ventrolateral preoptic nucleus(VLPO)of the *** briefly discuss recent literature reporting the role of VLPO astrocytes in regulating sleep-associated behaviors.

关键词： sleep ventrolateral astrocytes

Preparation of patterned SiC and SiCN microstructures

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第2期49卷 164-171页

作者： sung In-kyung kim Dong-pyo Department of Fine Chemical Engineering and Chemistry of Chungnam National University TaejonSouth Korea 305-764

Patterned SiC and SiCN microstructures were successfully fabricated on the silicon substrates by using polydimethylsiloxane (PDMS) elastometric stamp as template, polycarbosilane (PCS) and polysilazane (PSZ) as preceramic polymers. The preparing process was followed by precursor infiltration, the curing of the precursor, demolding of the template and pyrolysis of the cured preceramic polymer pattern. It shows that the dimen- sions of the ceramic patterns can be tailored by using the PDMS molds with different di- mensions. The produced ceramic microstructures can be potentially applied in high tem- perature and high pressure environments due to the advanced properties of the SiC and SiCN ceramics.

关键词： micro-fabrication technique, soft lithography, elastomeric stamp, non-oxide ceramics, patterning.

The validity of the Reynolds equation in spool valve analysis considering cavitation

在线全文

学校读者我要写书评

暂无评论

Friction 2016年第3期4卷 266-276页

作者： sung-Ho HONG kyung-Woong kim School of Mechanical Aerospace & Systems Engineering Korea Advanced Institute of Science and Technology 291 Daehak-ro Yuseong-guDaejeon 305-701 Republic of Korea

The purpose of this research is to investigate the validity of the Reynolds equation in spool valve analysis under cavitation. This study is carried out for a laminar and isothermal flow between a sleeve and spool with grooves. The pressure and lateral force obtained from the Reynolds equation and the Navier-Stokes equation are compared with variations of aspect ratio, cross sectional area, and number of grooves. The cavitation phenomenon is considered by using a cavitation model in the Navier-Stokes equation and the Reynolds cavitation boundary condition in the Reynolds equation. A large difference of more than 20% is found between the equations for a lateral force of spool valve with many grooves. It was found that the Reynolds equation is not suitable for calculation of a lateral force of the spool valve with multiple-grooves of which the width and depth are even larger than the clearance under cavitation.

关键词： validity Reynolds equation Navier-Stokes equation spool valve cavitation

Dynamic modeling and analysis of vortex filament motion using a novel curve-fitting method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2016年第1期29卷 53-65页

作者： Chang-Joo kim Soo Hyung Park Sang kyung sung sung-Nam Jung Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea

Applications of a novel curve-fitting technique are presented to efficiently predict the motion of the vortex filament, which is trailed from a rigid body such as wings and rotors. The gov- erning equations of the motion, when a Lagrangian approach with the present curve-fitting method is applied, can be transformed into an easily solvable form of the system of nonlinear ordinary dif- ferential equations. The applicability of Bezier curves, B-spline, and Lagrange interpolating polyno- mials is investigated. Local Lagrange interpolating polynomials with a shift operator are proposed as the best selection for applications, since it provides superior system characteristics with minimum computing time, compared to other methods. In addition, the Gauss quadrature formula with local refinement strategy has been developed for an accurate prediction of the induced velocity computed with the line integration of the Biot-Savart law. Rotary-wing problems including a vortex ring problem are analyzed to show the efficiency, accuracy, and flexibility in the applications of the pro- posed method.

关键词： Aerodynamics Biot-Savart law Curve-fitting method Free-vortex wake Rotary wing Vortex filament

Soleus arthrogenic muscle inhibition following acute lateral ankle sprain correlates with symptoms and ankle disability but not with postural control

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2024年第4期13卷 559-568,F0003页

作者： kyung-Min kim Joo-sung kim Alan R.Needle Department of Sport Science Sungkyunkwan UniversitySuwon-si 16419Republic of Korea Department of Health and Human Performance Texas State UniversitySan MarcosTX 78666USA Department of Public Health&Exercise Science Appalachian State UniversityBooneNC 28608USA Department of Rehabilitation Science Appalachian State UniversityBooneNC 28608USA

Background:Acute lateral ankle sprains(ALAS)are associated with long-term impairments and instability tied to altered neural *** muscle inhibition(AMI)has been observed in this population;however,relationships with injury-related impairments are unclear,potentially due to the resting,prone position in which AMI is typically *** AMI during bipedal stance may provide a better understanding of this ***:AMI was assessed in 38 young adults(19 ALAS within 72 h of injury:10 males,21.4±2.7 years;19 healthy controls:10 males,21.9±2.2 years;mean±SD)using the Hoffmann reflex(H-reflex)during bipedal *** stimulation was administered to identify the _(max)imal H-reflex(H_(max))and _(max)imal motor response(M_(max))from the soleus,fibularis longus,and tibialis anterior *** primary outcome measure was the H_(max)/M_(max) *** outcomes included acute symptoms(pain and swelling),postural control during bipedal stance,and self-reported ***:No significant group-by-limb interactions were observed for any ***,a significant group main effect was observed in the soleus muscle(F(1,35)=6.82,p=0.013),indicating significantly lower H_(max)/M_(max) ratios following ALAS(0.38±0.20)compared to healthy controls(0.53±0.16).Furthermore,lower H_(max)/M_(max) ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural ***:This study supports previous evidence of AMI in patients with ALAS,providing insight into neurophysiologic impacts of musculoskeletal *** results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.

关键词： Acute injuries Balance Hoffmann reflex Neural excitability Patient-reported outcomes

Morphology Control of Bi2S3 Nanostructures and the Formation Mechanism

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2013年第6期31卷 752-756页

作者： HeeJin kim Ji-eun Park kyung kim Mi-kyung Han sung-Jin kim Wooyoung Lee Department of Materials Science and Engineering Yonsei University Seou1120- 749 Korea Department of Chemistry and Nano Science Ewha Womans University Seoul 120-750 Korea

Bismuthinite （Bi2S3）nanostructures were prepared by a hydrothermal method with sodium ethylenediamine- tetraacetate （EDTA-Na2）. The morphology of Bi2S3 nanostructures was changed from a nanorod to a nanoplate by presence of the EDTA-Na2. The altered morphology was caused by the capping effect of EDTA-Na2 with Bi3＋ ions, which induces the suboptimal growth direction due to partially blocking the preferential orientation direction. When the EDTA-Na2/Bi3＋ molar ratio= 1, the growth of Bi2S3 nanostructures was not allowed due to the chelating effect of EDTA-Na2. The obtained Bi2S3 nanorods, stacked nanorods, nanoplates and nanoparticles were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron mi- croscopy （HRTEM） and selected area electron diffraction （SAED） pattern. A possible formation mechanism of these morphologies was proposed. The successful synthesis of various morphologies of nanostructured Bi2S3 may open up new possibilities for thermoelectric, electronic and optoelectronic uses of nanodevices based on Bi2S3 nanostructure.

关键词： bismuth sulfide (Bi2S3) hydrothermal nanorod nanoplate thermoelectric material