检索结果-南通市图书馆

Transactions of Nonferrous Metals Society of China 2014年第7期24卷 2346-2351页

作者： Jewoosoo KIM Gwang-Seon JANG Mok-Soon KIM Jeong-Keun LEE division of Materials Science and Engineering Inha University r&d Center Dong Yang Piston Co. Ltd

Al-Si-Fe based alloys are attractive light-weight structural materials for automotive engine components because of their high wear resistance, low density and low thermal expansion. Al-17Si 5Fe-2Cu-lMg-lNi-lZr alloys were produced in compact form by a spark plasma sintering （SPS） technique using gas atomized powders. The mean grain size of the compact was 530 nm, and fine equiaxed grains and uniformly distributed precipitates were observed in the compact. The compressive deformation behavior of the SPSed materials was examined at various temperatures and strain rates. All the true stress-true strain curves showed steady state flow after reaching peak stress. The peak stress decreased with increasing test temperature and decreasing strain rate. In the deformed specimens, the equiaxed grain morphology and the dislocation microstructure within the equiaxed grains were observed. These facts strongly indicated the occurrence of dynamic recrystallization during high temperature deformation of the present alloy.

关键词： Al-Si-Fe alloy powder metallurgy spark plasma sintering, microstructure deformation

High Temperature Mechanical Properties of Ni-Al-Cr Based Alloys for Advanced die-Materials Applications

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 305-308页

作者： W.Y.Kim H.S.Kim Y.G.Yoo I.d.Yeo Advanced Materials r&d division Korea Institute of Industrial Technology7-47Songdo-dongYeonsu-gu

In this study, we report on advanced Ni3Al based high temperature structural alloys with Zr and B addition in order to apply in the fields of die-casting and high temperature press forming as die materials. Microstructures and mechanical properties of Ni3Al based intermetallic alloys produced by vacuum arc melting were investigated in terms of phase analysis by using a scanning electron microscope （SEM） equipped with an X-ray energy dispersive spectrometer （EdS）, an X-ray diffractometer （Xrd） and tensile test. The duplex microstructural feature consisting of γ＇ matrix phase and small intermetallic dispersoids was observed to be distributed over the whole microstructure. The ultimate tensile strength of the present alloy was superior to commercial iron-based and Ni-based die-materials especially in the high temperature region.

关键词： Intermetallic die material Alloying effect Mechanical property

Tensile creep and corrosion properties of Mg-2%Ca based cast alloys

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2011年第4期21卷 869-873页

作者： Jeong-Min KIM Joon-Sik PArK Ki-Tae KIM division of Advanced Materials Engineering Hanbat National University Incheon r&d Center Korea Institute of Industrial Technology

The relative effect of Zn addition to Mg-2%Ca based alloy on the creep and corrosion characteristics was compared with Al addition. The creep resistance of Mg-2%Ca based alloy at 175 ℃was improved by Zn addition more significantly than by Al addition. However, the Al addition showed more effective in enhancing corrosion resistance. Since the solidification range for Zn-added alloy was considerably wide, the cautious casting design may be necessary to produce high-quality castings.

关键词： magnesium calcium cast alloy creep corrosion

Effects of Mo and Zr on Microstructure,Mechanical Properties and Wear resistance of Fe-Al Based Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 309-312页

作者： I.d.Yeo H.S.Kim Y.G.Yoo W.Y.Kim Advanced Materials r&d division Korea Institute of Industrial Technology7-47Songdo-dongYeonsu-gu

In this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectroscope （EdS）. Two types of alloys were prepared by vacuum arc melting. One is Fe-28Al based alloys （d03 structured） with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys （B2 structured） produced with the same manner. For both types of alloys, Mo addition had found to exhibit an equiaxed microstructure, while dendritic structure was observed to show the effect of Zr addition. These microstructural features were more evinced with increasing content of alloying element. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys were superior to Fe-28Al based alloys over the whole temperature range investigated.

关键词： Fe-Al alloy Intermetallic Mechanical properties Wear resistance

The pseudogenes of eukaryotic translation elongation factors (EEFs): role in cancer and other human diseases

在线全文

学校读者我要写书评

暂无评论

Genes & diseases 2022年第4期9卷 941-958页

作者： Luigi Cristiano r&d division Prestige18 via VecchiaTerranuova BraccioliniAR 52028Italy

The eukaryotic translation elongation factors (EEFs), i.e. EEF1A1, EEF1A2, EEF1B2, EEF1d, EEF1G, EEF1E1 and EEF2, are coding-genes that play a central role in the elongation step of translation but are often altered in cancer. Less investigated are their pseudogenes. recently, it was demonstrated that pseudogenes have a key regulatory role in the cell, especially via non-coding rNAs, and that the aberrant expression of ncrNAs has an important role in cancer development and progression. The present review paper, for the first time, collects all that published about the EEFs pseudogenes to create a base for future investigations. For most of them, the studies are in their infancy, while for others the studies suggest their involvement in normal cell physiology but also in various human diseases. However, more investigations are needed to understand their functions in both normal and cancer cells and to define which can be useful biomarkers or therapeutic targets.

关键词： Cancer EEFs Non-coding rNA Pseudogene Translation Translation elongation factor

Spray,droplet evaporation,combustion,and emission characteristics of future transport fuels for compression-ignition engines:A review

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

Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 575-613页

作者： Leang So Khuong Nozomu Hashimoto Osamu Fujita division of Mechanical and Aerospace Engineering Faculty of Engineering Hokkaido University Faculty of Automotive Engineering National Polytechnic Institute of Cambodia

This review examines the potential of hydrogen, ammonia, and biodiesel as alternative fuels,focusing on spray dynamics, droplet evaporation, combustion, and emissions. Hydrogen offers superior combustion characteristics but faces challenges in NOxemissions. Strategies like nonpremixed direct injection, increased intake boost pressure, and low-pressure EGr are suggested for robust hydrogen combustion in compression-ignition engines. Control of hydrogen start of injection（SOI） and water injection（WI） are identified as effective techniques for reducing NOxemissions. Ammonia shows inferior combustion and higher NOxand unburned NH3emissions in the same conditions as conventional fuels with conventional engines. Understanding ammonia spray and evaporation conditions is significant for optimizing an ammonia-air mixture and minimizing wall impingement and ammonia trap in the crevice,thereby improving combustion and emission reduction. Increasing intake pressure, injection pressure, and EGr rate, employing a turbulent jet, and preheating ammonia improve efficiency and reduce NOxemissions. Utilizing ammonia combustion requires the implementation of after-treatment systems such as NH3adsorber and de NOxcatalysts to mitigate unburned NH3and NOxemissions. Biodiesel affects the fuel supply system, combustion, and emission characteristics according to its viscosity and density. Increasing injection pressure and blending with volatile fuels enhance spray and combustion. Optimum biodiesel preheating temperatures for the injection pump and injector are crucial for achieving the best pump capacity and spray formation. By utilizing biodiesel-POdE blends and investigating low-temperature biodiesel combustions, there is potential to improve thermal efficiency and PMNOxtrade-off. Therefore, carbon-neutral fuel adoption should be accelerated to mitigate CO2emissions, highlighting the importance of combustion techniques and emissions reduction strategies.

关键词： Carbon-neutral fuels Spray formation droplet evaporation Injection strategies Combustion efficiency Emission reduction

Evaluation of excavation damaged zones(EdZs)in Horonobe Underground research Laboratory(UrL)

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 rock Mechanics and Geotechnical Engineering 2024年第2期16卷 365-378页

作者： Koji Hata Sumio Niunoya Kazuhei Aoyagi Nobukatsu Miyara Obayashi Corporation Technology Research InstituteTechnology DivisionKiyoseTokyo204-8558Japan Obayashi Corporation Nuclear Facilities DivisionSinagawaTokyo108-8502Japan Japan Atomic Energy Agency Horonobe Underground Research CenterHoronobeHokkaido098-3224Japan

Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress *** this influenced zone,new cracks and discontinuities are created or propagate in the rock ***,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability *** authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting r&d activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal *** a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass ***,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground research *** measurement results show that AEs occur frequently up to 1.5 m from the wall during *** addition,hydraulic conductivity increased by 2e4 orders of *** analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused *** on this,a conceptual model is developed to represent the excavation damaged zone(EdZ),which contributes to the safe geological disposal of radioactive waste.

关键词： Excavation damaged zone(EdZ) Optical sensor Long-term monitoring Acoustic emission(AE) Shaft sinking

Elucidating regulatory processes of intense physical activity by multi-omics analysis

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

Military Medical research 2024年第4期11卷 479-499页

作者： Ernesto S.Nakayasu Marina A.Gritsenko Young-Mo Kim Jennifer E.Kyle Kelly G.Stratton Carrie d.Nicora Nathalie Munoz Kathleen M.Navarro daniel Claborne Yuqian Gao Karl K.Weitz Vanessa L.Paurus Kent J.Bloodsworth Kelsey A.Allen Lisa M.Bramer Fernando Montes Kathleen A.Clark Grant Tietje Justin Teeguarden Kristin E.Burnum-Johnson Biological Sciences division Pacific Northwest National LaboratoryRichlandWA 99352USA Environmental and Molecular Sciences division Pacific Northwest National LaboratoryRichlandWA 99352USA Centers for disease Control and Prevention National Institute for Occupational Safety and HealthWestern States DivisionDenverCO 80204USA Computational Analytics division Pacific Northwest National LaboratoryRichlandWA 99352USA National Security directorate Pacific Northwest National LaboratoryRichlandWA 99352USA Los Angeles County Fire department Los AngelesCA 90063USA Centers for disease Control and Prevention National Institute for Occupational Safety and HealthRespiratory Health DivisionMorgantownWV 26505USA Environmental and Molecular Toxicology Oregon State UniversityCorvallisOR 97331USA

Background:Physiological and biochemical processes across tissues of the body are regulated in response to the high demands of intense physical activity in several occupations,such as firefighting,law enforcement,military,and sports.A better understanding of such processes can ultimately help improve human performance and prevent illnesses in the work ***:To study regulatory processes in intense physical activity simulating real-life conditions,we performed a multi-omics analysis of 3 biofluids(blood plasma,urine,and saliva)collected from 11 wildland firefighters before and after a 45 min,intense exercise *** profiles ***-exercise were compared by Student’s t-test followed by pathway analysis and comparison between the different omics ***:Our multi-omics analysis identified and quantified 3835 proteins,730 lipids and 182 metabolites combining the 3 different types of *** blood plasma analysis revealed signatures of tissue damage and acute repair response accompanied by enhanced carbon metabolism to meet energy *** urine analysis showed a strong,concomitant regulation of 6 out of 8 identified proteins from the renin-angiotensin system supporting increased excretion of catabolites,reabsorption of nutrients and maintenance of fluid *** saliva,we observed a decrease in 3 pro-inflammatory cytokines and an increase in 8 antimicrobial peptides.A systematic literature review identified 6 papers that support an altered susceptibility to respiratory ***:This study shows simultaneous regulatory signatures in biofluids indicative of homeostatic maintenance during intense physical activity with possible effects on increased infection susceptibility,suggesting that caution against respiratory diseases could benefit workers on highly physical demanding jobs.

关键词： Multi-omics analysis Intense exercise Human performance Biofluids Metabolism Immunity

Software for Small-scale robotics: A review

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2018年第5期15卷 515-524页

作者： Tobias Tiemerding Sergej Fatikow department of Computing Science Division Microrobotics and Control Engineering (AMiR) University of Oldenburg OFFIS–Institute for Information Technology R&D Division Automation and Integration Technology (AIT)

In recent years, a large number of relatively advanced and often ready-to-use robotic hardware components and systems have been developed for small-scale use. As these tools are mature, there is now a shift towards advanced applications. These often require automation and demand reliability, efficiency and decisional autonomy. New software tools and algorithms for artificial intelligence（AI） and machine learning（ML） can help here. However, since there are many software-based control approaches for small-scale robotics, it is rather unclear how these can be integrated and which approach may be used as a starting point. Therefore, this paper attempts to shed light on existing approaches with their advantages and disadvantages compared to established requirements. For this purpose, a survey was conducted in the target group. The software categories presented include vendor-provided software, robotic software frameworks（rSF）, scientific software and in-house developed software（IHdS）. Typical representatives for each category are described in detail, including Smar Act precision tool commander, Math Works Matlab and national instruments Lab VIEW, as well as the robot operating system（rOS）. The identified software categories and their representatives are rated for end user satisfaction based on functional and non-functional requirements, recommendations and learning curves. The paper concludes with a recommendation of rOS as a basis for future work.

关键词： robotic control software engineering micro/nano robotics artificial intelligence (AI) machine learning (ML) open

Highly Elastic,Bioresorbable Polymeric Materials for Stretchable,Transient Electronic Systems

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第6期16卷 1-13页

作者： Jeong‑Woong Shin dong‑Je Kim Tae‑Min Jang Won Bae Han Joong Hoon Lee Gwan‑Jin Ko Seung Min Yang Kaveti rajaram Sungkeun Han Heeseok Kang Jun Hyeon Lim Chan‑Hwi Eom Amay J.Bandodkar Hanul Min Suk‑Won Hwang KU‑KIST Graduate School of Converging Science and Technology Korea University145 Anam‑roSeongbuk‑guSeoul 02841Republic of Korea SK Hynix 2091Gyeongchung‑daeroBubal‑eupIcheon‑siGyeonggi‑do 17336Republic of Korea Hanwha Systems Co. Ltd.188Pangyoyeok‑roBundang‑guSeongnam‑siGyeonggi‑do 13524Republic of Korea department of Electrical and Computer Engineering North Carolina State UniversityRaleighNC 27606USA Center for Advanced Self‑Powered Systems of Integrated Sensors and Technologies(ASSIST) North Carolina State UniversityRaleighNC 27606USA department of Integrative Energy Engineering Korea University145 Anam‑roSeongbuk‑guSeoul 02841Republic of Korea Biomaterials research Center Korea Institute of Science and Technology(KIST)5 Hwarang‑ro 14‑gilSeongbuk‑guSeoul 02792Republic of Korea Semiconductor r&d Center Samsung Electronics Co.Ltd.Hwaseong‑siGyeonggi‑do 18448Republic of Korea Center for Advanced Biomolecular recognition Biomedical Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea

Substrates or encapsulants in soft and stretchable formats are key components for transient,bioresorbable electronic systems;however,elastomeric polymers with desired mechanical and biochemical properties are very limited compared to nontransient ***,we introduce a bioresorbable elastomer,poly(glycolide-co-ε-caprolactone)(PGCL),that contains excellent material properties including high elongation-at-break(resilience and toughness,and tunable dissolution *** of PGCLs as polymer matrices,in combination with conducing polymers,yields stretchable,conductive composites for degradable interconnects,sensors,and actuators,which can reliably function under external *** of device components with wireless modules demonstrates elastic,transient electronic suture system with on-demand drug delivery for rapid recovery of postsurgical wounds in soft,time-dynamic tissues.

关键词： Biodegradable elastomer Conductive polymer composites Biomedical device Transient electronics