检索结果-南通市图书馆

Mg Alloy Foam Fabrication via Melt Foaming Method

在线全文

学校读者我要写书评

暂无评论

j.urnal of Materials Science & Technology 2008年第3期24卷 302-304页

作者： Changhwan SEO Bo-young HUR i-Cube Center ERISchool of Nano & Advanced Materials EngineeringGyeongsang National University

For the first time AZ91 （MgAl9Zn1） and AM60 （MgAl6） Mg alloy foams with homogeneous pore structures were prepared successfully via melt foaming method using CaCO3 as blowing agent. It is revealed that the blowing gas to foam the melt is not CO2 but CO, which comes from liquid-solid reaction between Mg melt. The reaction temperature is more than 100℃ lower than CaCO3 decomposition, which makes Mg alloy melts foam into cellular structure much more easily in the temperature range from 690℃ to 750℃.

关键词： Mg alloy foam CaCO3 Blowing gas

Effects of three consecutive monthly intravitreal inj.ction of ranibizumab for polypoidal choroidal vasculopathy in Korea

在线全文

学校读者我要写书评

暂无评论

International j.urnal of Ophthalmology(English edition) 2015年第2期8卷 315-320页

作者： young Gun Park Seungbum Kang young j.ng Roh Department of Ophthalmology College of Medicine The Catholic University of Korea Yeouido St. Mary's Hospital Department of Ophthalmology The Catholic University of Korea Daejeon St. Mary's Hospital

AIM: To evaluate the efficacy and safety of three consecutive monthly inj.ctions of intravitreal ranibizumab for the treatment of polypoidal choroidal vasculopathy(PCV) in ***: A retrospective chart review of 25 patients(27 eyes) with PCV was conducted. Patients received three initial monthly intravitreal inj.ctions(0.5 mg) of ranibizumab and were monitored monthly for 12 mo from j.nuary 2010 to October 2011. Reinj.ction of ranibizumab after three initial monthly loading was administered on an as-needed basis, guided by the optical coherence tomography(OCT), fluorescein angiography(FA) and indocyanine green angiography(ICGA). The main outcomes were the changes of the mean best corrected Snellen visual acuity(VA), central macular thickness(CMT) by OCT, the changes of polyps and branching vascular network by FA and ICGA, and total number of inj.ctions received by patients during the 12 ***: The mean best corrected Snellen visual acuities at baseline, 1, 3, 6 and 12 mo after primary inj.ction were 0.77 ±0.59, 0.76 ±0.53, 0.70 ±0.47, 0.63 ±0.43,0.61 ±0.43, 0.62 ±0.42 log MAR, respectively, and showed significant improvement at 3, 6, 12mo(P =0.003, P =0.002,P =0.018, Wilcoxon signed-rank test). The mean CMT at baseline, 1, 2, 3, 6, and 12 mo was 312.41 ±66.38 μm,244.59 ±71.47 μm, 232.32 ±69.41 μm, 226.69 ±69.03 μm,228.62 ±37.07 μm, 227.59 ±51.01 μm respectively, and showed significant reduction(all P j.ctions were given in the 12-month period, which equaled to a mean of 3.92(range, 3-6) times. Sixteen of the 27 treatedeyes had additional 1.56 ±0.91 inj.ctions. The others(11eyes) had j.st 3 consecutive ***: An initial loading dose of three monthly ranibizumab inj.ctions is a safe and effective method in treating PCV, with visual and anatomical improvement over one ye

关键词： ranibizumab polypoidal choroidal vasculopathy intravitral inj.ction

2.47 GPa grade ultra-strong 15Co-12Ni secondary hardening steel with superior ductility and fracture toughness

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

j.urnal of Materials Science & Technology 2021年第7期66卷 36-45页

作者： young-Kyun Kim Kyu-Sik Kim young-Beum Song j.ng Hyo Park Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon22212Republic of Korea Agency for Defense Development(ADD) Yuseong-guDaegeon34186Republic of Korea

This study investigated the effect of multi-step heat treatment on the microstructure, mechanical properties and fracture behavior of thick 15 Co-12 Ni secondary hardening steel. As-quenched sample was found to have elongated prior austenite grain(PAG) and coarse lenticular martensitic structure. On the other hand, heat-treated sample was observed to have fine lenticular martensitic structure due to fine PAG size and a lot of nano-sized carbides. Also, after heat treatment, nano-scale reverted austenite film was formed at the martensite interfaces. The heat-treated sample showed 2.47 GPa superior tensile strength and superior elongation of about 12 %. The high strength was mainly due to fine block size and high number density of nano-sized carbides. The average value of plane strain fracture toughness(KIC) was 29.3 MPa m1/2, which indicated a good fracture toughness even with the high tensile strength. The tensile fracture surface was observed to have ductile fracture mode(cup-and-cone) and the formation of about ~1 μm ultra-fine dimples. In addition to this, nano-sized carbides were observed within the *** findings suggested that the nano-sized carbide had a positive effect not only on the strength but also on the ductility of the alloy. The fractured surface after toughness test, also showed ductile fracture mode with a lot of dimples. Based on the above results, correlation among microstructural evolution,deformation and fracture mechanisms along the heat-treatment was also discussed.

关键词： Ultra-high strength High Co-Ni secondary hardening steel Microstructure Tensile properties Fracture toughness Reverted austenite

Plasmid DNA-loaded asymmetrically porous membrane for guided bone regeneration

在线全文

学校读者我要写书评

暂无评论

j.urnal of Materials Science & Technology 2021年第4期63卷 161-171页

作者： Se Heang Oh j.ne-Ho Byun So young Chun young-j.o j.ng j.n Ho Lee Department of Nanobiomedical Science Dankook UniversityCheonan 31116Republic of Korea Department of Oral and Maxillofacial Surgery Gyeongsang National University School of MedicineGyeongsang National University HospitalInstitute of Health SciencesGyeongsang National UniversityJinju 52727Republic of Korea BioMedical Research Institute Kyungpook National University HospitalDaegu 41404Republic of Korea Department of Advanced Materials Hannam UniversityDaejeon 34054Republic of Korea

Although bone defects can be restored spontaneously,bone reconstruction with sufficient strength and volume continues to be a challenge in clinical *** recent years,the use of a variety of biomaterials with bioactivity has been attempted to compensate for this ***,we fabricated a pDNA(encoding for BMP-2)-loaded asymmetrically porous polycaprolactone(PCL)/Pluronic F127 membrane as a bioactive guided bone regeneration(GBR)membrane,using a modified immersion-precipitation *** was observed that the GBR membrane allows continuous release of pDNA for more than20 *** pDNA was sufficiently transfected into human bone marrow stem cells(h BMSCs)without significant cytotoxicity and the gene-transfected cells showed prolonged synthesis of *** in vitro osteogenic differentiation and in vivo animal studies,the effective induction of osteogenic differentiation of h BMSCs and enhanced bone regeneration by the pDNA-loaded asymmetrically porous PCL/Pluronic F127 membrane was observed,suggesting that the pDNA-loaded membrane as a bioactive GBR membrane can be an alternative therapeutic technique for effective bone regeneration.

关键词： loaded porous attempted

Effects of Nitrogen Source and Bacterial Elicitor on Isoflavone Accumulation in Root Cultures of Albizzia kalkora （Roxb.） Prain

在线全文

学校读者我要写书评

暂无评论

j.urnal of Integrative Plant Biology 2006年第9期48卷 1108-1114页

作者： So-young Park Wi-young Lee youngki Park j.n-Kwon Ahn Biotechnology Division Korea Forest Research Institute Suwon 441-350 Korea

Changes in cellular isoflavone （daidzein and genistein） contents were monitored in root cultures of Albizzia kalkora （Roxb.） Prain after feeding different ratios of NH4^＋/NO3^- and treatment with a biotic elicitor （three strains of Rhizobium sp.）. The NH4^＋/NO3^- ratio appears to be positively correlated with daidzein content in the roots and shows a negative correlation with genistein. Among the three different strains of Rhizobium used, the strain ATCC 15834 caused a 35% increase in daidzein production by infection. In the case of genistein, maximum production （94%） was obtained when cultures were treated on Day 6 by the strains ATCC 15834 and KCTC 1541. The biosynthetic pathway of the two isoflavones apparently reacts differently to the same culture conditions and the same strains of Rhizobium. Therefore, the present data suggest that the production of daidzein and genistein could be modulated by changing the NH4^＋/NO3^- ratio and the application of Rhizobium.

关键词： Albizzia kalkora infection isoflavone nitrogen root culture

Weldability evaluation and tensile strength estimation model for aluminum alloy lap j.int welding using hybrid system with laser and scanner head

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

中国有色金属学会会刊：英文版 2012年第S3期22卷 596-604页

作者： Dong-Yoon KIM young-Whan PARK Department of Mechanical Engineering Pukyong National University

Aluminum welding using a hybrid system with a laser and scanner welding head was performed under various welding conditions to verify the feasibility of applying an aluminum alloy to a car *** experimental material was 5j.2 aluminum alloy,and the laser power,welding speed,and laser incidence angle were used as the control *** weld bead shape and the tensile shear strength were evaluated in order to understand the aluminum lap j.int weld *** of variance (ANOVA) was conducted to identify the effect of the process variables on the tensile shear *** strength estimation models using three different regression models were also *** input variables were the laser power,welding speed,and laser incidence angle,and the output was the tensile shear *** the models,the second-order polynomial estimation model had the best estimation performance,and the average error rate of this model was 0.058.

关键词： laser welding scanner remote welding 5j.2 aluminum alloy regression model

Development of a Portable Electro-Mechanical Educational Model for Variable Rate Center Pivot Irrigation Technology

在线全文

学校读者我要写书评

暂无评论

j.urnal of Water Resource and Protection 2016年第4期8卷 449-458页

作者： young j. Han Ahmad Khalilian j.se Payero Nicholas Rogers Department of Agricultural and Environmental Sciences Clemson University Clemson SC USA Edisto Research and Education Center Department of Agricultural and Environmental Sciences Clemson University Blackville SC USA

Center pivot irrigation systems usually apply a relatively uniform amount of water to fields that are often inherently variable, which could lead to significant waste of water and energy. To address this issue, our team is now developing an Intelligent Center Pivot (ICP) by integrating sensor-based irrigation scheduling with variable rate irrigation technology. However, before this technology can be applied in commercial production, it is necessary to educate growers about its practicality and potential benefits. The obj.ctive of this study was to develop a portable tabletop intelligent center pivot model (ICPDemo) to demonstrate and promote adoption of the ICP technology. This paper describes an ICPDemo constructed in 2014, including the design specifications, electro-mechanical design, control strategy, and performance. The ICPDemo has performed according to design specifications and is successfully being used to demonstrate the benefits and effectiveness of ICP technology for irrigation scheduling.

关键词： Irrigation Center Pivot Irrigation Electro-Mechanical Model Sensors Control Variable Rate Irrigation

Sliding Wear Behavior of Plasma Sprayed Alumina-Based Composite Coatings against Al_2O_3 Ball

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

j.urnal of Materials Science & Technology 2004年第4期20卷 395-401页

作者： Minh-quyLe young-hunChae Seock-samKim GraduateSchool SchoolofMechanicalEngineeringKyungpookNationalUniversityDaeguSouthKorea EngineeringTribologyResearchInstitute KyungpookNationalUniversityDaeguSouthKorea SchoolofMechanicalEngineering KyungpookNationalUniversityDaeguSouthKorea

The sliding wear behaviors of a single layer AI2O3-30 wt pct ZrO2, a double layer AI2O3-30 wt pct ZrO2/Ni-Cr and a single layer AI2O3-13 wt pct TiO2 coating deposited on low carbon steel by plasma spraying were investigated under lubricated conditions with various normal loads. The plastic deformation, detachment and pull out of splats were involved in the wear process of the studied coatings under test conditions. Crack propagation was found in AI2O3-13 wt pct TiO2 under loads of 70 and 100 N and in AI2O3-30 wt pct ZrO2/Ni-Cr under a load of 130 N. While increasing the normal load, the wear rates of AI2O3-30 wt pct ZrO2 and AI2O3-30 wt pct ZrO2/Ni-Cr slightly increased, the wear rate of AI2O3-13 wt pct TiO2 increased rapidly. The results showed that the Ni-Cr bonding layer improved the wear resistance of the coating system even it is relatively thin compared with the outer coating layer. The influence of this bonding layer on wear behavior of the coating increased as increasing the normal load.

关键词： Coating Plasma spray Wear behavior

Comparison of mesophilic and thermophilic anaerobic digestions of thermal hydrolysis pretreated swine manure: Process performance,microbial communities and energy balance

在线全文

学校读者我要写书评

暂无评论

j.urnal of Environmental Sciences 2023年第4期126卷 222-233页

作者： Xiaohui Liu Changmin Lee j.e young Kim Department of Civil and Environmental Engineering Seoul National UniversitySeoul 08826Korea

Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatment (THP, 170℃/10 bar), to investigate its potential for maximizing biogas yield, securing successful digestion and microbial diversity, as well as improving energy balance. Four lab-scale continuously stirred tank reactors were operated for 300 days and compared with each other, i.e., reactor 1 (raw SM fed in mesophilic AD:RSM-MAD), reactor 2 (THP-treated SM fed in MAD:TSM-MAD), reactor 3 (RSM-TAD),and reactor 4 (TSM-TAD). The results showed that THP was efficient to increase methane production of SM, TSM-TAD mode led to the highest methane yield (129.8±40.5 mL-CH_(4)/gVS/day) among the tests (p 700 mg/L) or volatile fatty acids (> 6000 mg/L) accumulation compared with MAD in start-up phase, TSM-TAD treatment mode behaved a sustainable digestion process in a long-term operation. For TSM-TAD scenario, higher Shannon–Weaver (3.873) and lower Simpson index (0.061) indicated this mode ensured and enlarged the diversity of bacteria communities. Phylum Bathyarchaeota was dominant (59.3%-90.0%) in archaea community,followed by Euryarchaeota in the four reactors. RSM-MAD treatment mode achieved the highest energy output (4.65 Gj.day), TSM-TAD was less effective (-17.38 Gj.day) due to increased energy demands. Thus improving the energetic efficiency of THP units is recommended for the development of TSM-TAD treatment mode.

关键词： Thermal hydrolysis pretreatment Digestion temperature Process performances Microbial communities Energy balance