检索结果-南通市图书馆

Synthesis of self-assembled nanorod vanadium oxide bundles by sonochemical treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas chemistry 2009年第3期18卷 312-318页

作者： Y.H.Taufiq-Yap Y.c.Wong Z.Zainal M.Z.Hussein centre of Excellence for catalysis Science and Technology Faculty of ScienceUniversiti Putra Malaysia Department of chemistry Faculty of ScienceUniversiti Putra Malaysia

Self-assembled nanorod of vanadium oxide bundles were synthesized by treating bulk V2O5 with high intensity sonochemical technique. The synthesized materials were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM） and temperature-programmed reduction （TPR） in H2. catalytic behaviour of the materials over anaerobic n-butane oxidation was studied through temperature-programmed reaction （TPRn）. catalytic evaluation of the sonochemical treated V2O5 products was also studied on microreactor. XRD patterns of all the vanadium samples were perfectly indexed to V2O5. The morphologies of the nanorod vanadium oxides as shown in SEM and TEM depended on the duration of the ultrasound irradiation. Prolonging the ultrasound irradiation duration resulted in materials with uniform, well defined shapes and surface structures and smaller size of nanorod vanadium oxide bundles. H2-TPR profiles showed that larger amount of oxygen species were removed from the nanorod V2O5 compared to the bulk. Furthermore, the nanorod vanadium oxide bundles, which were produced after 90, 120 and 180 min of sonochemical treatment, showed an additional reduction peak at lower temperature （-850 K）, suggesting the presence of some highly active oxygen species. TPRn in n-butane/He over these materials showed that the nanorod V2O5 with highly active oxygen species showed markedly higher activity than the bulk material, which was further proven by catalytic oxidation of n-butane.

关键词： nanorod vanadium oxide sonochemical treatment butane oxidation

Effect of Pressure and Temperature on Phase Transformation and Properties of Titanium Aluminide Obtained through Reaction Synthesis

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2010年第8期26卷 693-704页

作者： R.K.Gupta Bhanu Pant Vijaya Agarwala R.c.Agarwala P.P.Sinha Vikram Sarabhai Space centre ISROTrivandrum-695 022India Indian Institute of Technology Roorkee

Reaction synthesis process has been used to develop γ titanium aluminide using elemental powders. Powder mixture of Ti-48 at. pct AI was prepared in ball mill and reaction synthesis was carried out in hot press with varying temperature and pressure. Titanium aluminide synthesized under high pressure and temperature resulted in better properties with respect to densification, homogenization response, mechanical properties and oxidation resistance as compared to that synthesized under low pressure and temperature. AI rich phases were observed in as-synthesized condition in all the experiments. However, some Ti rich phases were also found in high pressure-temperature synthesized samples. Density, hardness and tensile strength have been correlated with applied pressure through empirical relations. Variation in density with pressure is found to be logarithmic whereas hardness and tensile strength variation with pressure is polynomial.

关键词： Titanium aluminide Reaction synthesis Phase transformation

Tribological and vibrational characteristics of AISI 316L tested at elevated temperature and 600 Torr vacuum

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第1期15卷 58-64页

作者： K.Arul Raj M.P.Arunkumar P.K.c.Kanigalpula M.Karthikeyan Department of Mechanical Engineering Koneru Lakshmaiah Education Foundation Department of Mechanical Engineering RajaRajeswari College of Engineering

Friction and wear studies enable the investigation of material interaction between two sliding surfaces in contact. In the present investigation, the coefficient of friction and the wear resistance of AISI 316 L parts were studied under self-mating, dry sliding conditions using a pin-on-disc type configuration. The experiments were conducted at vacuum based high temperature pin-on-disc tribometer. The 4 mm diameter pin and 180 mm diameter disc were subjected to varying sliding velocities(0.5, 0.75 and 1.5 m/s) and were operated in 200, 400, 500 and 580 ℃ temperature at 600 Torr vacuum. The variation of specific wear rates with sliding velocities and different environmental conditions was studied. The morphology of sliding/rubbed surfaces was observed using Scanning Electron Microscope. In summary, it was found that a severe to mild wear transition occurred in sliding under operating conditions. Increased wear rates have been observed for 500 and 580 ℃ with increasing sliding velocity. Adhesive wear has been found to be predominant at 500 and 580 ℃ where as de-lamination has been observed at ambient temperature,200 and 400 ℃ in vacuum. The present paper also carried out the numerical analysis of the vibration behavior of AISI 316 L under thermal environment. Results revealed that at high temperature vibrational amplitude and natural frequency is significantly reduced. This can be attributed to the reduction in stiffness of the material at elevated temperatures. This high amplitude vibration during service can lead to high wear rate.

关键词： Pin-on-disc Sliding wear Vacuum De-lamination Scanning electron microscope Vibration

Stable Fano-like plasmonic resonance: its impact on the reversal of far-and near-field optical binding force

在线全文

学校读者我要写书评

暂无评论

communications in Theoretical Physics 2020年第4期72卷 89-105页

作者： Hamim Mahmud Rivy M R c Mahdy Nabila Masud Ziaur Rahman Jony Saikat chandra Das Department of Electrical&computer Engineering North South UniversityBashundharaDhaka1229Bangladesh School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang Ave639798 Singapore Pi Labs Bangladesh LTD ARA Bhaban39Kazi Nazrul Islam AvenueKawran BazarDhaka 1215Bangladesh

Even for a 100 nm interparticle distance or a small change in particle shape,optical Fano-like plasmonic resonance mode usually vanishes *** would be remarkable if stable Fano-like resonance could somehow be achieved in distinctly shaped nanoparticles for more than 1μm interparticle distance,which corresponds to the far electromagnetic field *** such far-field Fano-like plasmonic resonance can be achieved,controlling the reversal of the far-field binding force can be attained,like the currently reported reversals for near-field *** this work,we have proposed an optical set-up to achieve such a robust and stable Fano-like plasmonic resonance,and comparatively studied its remarkable impact on controlling the reversal of near-and far-field optical binding *** our proposed set-up,the distinctly shaped plasmonic tetramers are half immersed(***-benzene)in an inhomogeneous dielectric interface and illuminated by?circular?polarized *** have demonstrated significant differences between near-and far-field optical binding forces along with the Lorentz force field,which partially depends on the object’s shape.A clear connection is shown between the far-field binding force and the resonant modes,along with a generic mechanism to achieve controllable Fano-like plasmonic resonance and the reversal of the optical binding force in both far-and near-field configurations.

关键词： Fano resonance optical binding force Lorentz force plasmonic tetramer

Determination of urine-derived odorous compounds in a source separation sanitation system

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2017年第2期29卷 240-249页

作者： Bianxia Liu Apostolos Giannis Ailu chen Jiefeng Zhang Victor W.c.chang Jing-Yuan Wang .Residues and Resource Reclamation centre(R3c) Nanyang Environment and Water Research InstituteNanyang Technological University1 Cleantech LoopCleanTech OneSingapore 637141Singapore School of civil and Environmental Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore

Source separation sanitation systems have attracted more and more attention ***, separate urine collection and treatment could induce odor issues, especially in large scale application. In order to avoid such issues, it is necessary to monitor the odor related compounds that might be generated during urine storage. This study investigated the odorous compounds that emitted from source-separated human urine under different hydrolysis conditions. Batch experiments were conducted to investigate the effect of temperature, stale/fresh urine ratio and urine dilution on odor emissions. It was found that ammonia, dimethyl disulfide, allyl methyl sulfide and 4-heptanone were the main odorous compounds generated from human urine, with headspace concentrations hundreds of times higher than their respective odor thresholds. Furthermore, the high temperature accelerated urine hydrolysis and liquid–gas mass transfer, resulting a remarkable increase of odor emissions from the urine solution. The addition of stale urine enhanced urine hydrolysis and expedited odor emissions. On the contrary, diluted urine emitted less odorous compounds ascribed to reduced concentrations of odorant precursors. In addition,this study quantified the odor emissions and revealed the constraints of urine source separation in real-world applications. To address the odor issue, several control strategies are recommended for odor mitigation or elimination from an engineering perspective.

关键词： Odor emissions Volatile organic compounds(VOcs) Urine hydrolysis Source separation Gas chromatography mass spectrometry(Gc–MS)

Towards high-mobility In2xGa2-2xO3 nanowire field-effecttransistors

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第11期11卷 5935-5945页

作者： Ziyao Zhou changyong Lan SenPo Yip Renjie Wei Dapan Li Lei Shu Johnny c. Ho Department of Materials Science and Engineering City University of Hong Kong Kowloon Hong Kong 999077 China School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu 610054 China Shenzhen Research Institute City University of Hang Kong Shenzhen S 18057 China State Key Laboratory of Millimeter Waves City University of Hang Kong Kowloon Hang Kong 999077 China

Recently, owing to the excellent electrical and optical properties, n-type In2O3 nanowires (NWs) have attracted tremendous attention for application in memory devices, solar cells, and ultra-violet photodetectors. However, the relatively low electron mobility of In2O3 NWs grown by chemical vapor deposition (cVD) has limited their further utilization. In this study, utilizing in-situ Ga alloying, highly crystalline, uniform, and thin In2xGa2−2xO3 NWs with diameters down to 30 nm were successfully prepared via ambient-pressure cVD. Introducing an optimal amount of Ga (10 at.%) into the In2O3 lattice was found to effectively enhance the crystal quality and reduce the number of oxygen vacancies in the NWs. A further increase in the Ga concentration adversely induced the formation of a resistive β-Ga2O3 phase, thereby deteriorating the electrical properties of the NWs. Importantly, when configured into global back-gated NW field-effect transistors, the optimized In1.8Ga0.2O3 NWs exhibit significantly enhanced electron mobility reaching up to 750 cm2·V–1·s–1 as compared with that of the pure In2O3 NW, which can be attributed to the reduction in the number of oxygen vacancies and ionized impurity scattering centers. Highly ordered NW parallel arrayed devices were also fabricated to demonstrate the versatility and potency of these NWs for next-generation, large-scale, and high-performance nanoelectronics, sensors, etc.

关键词： In 2 O 3 In 2 x Ga 2−2 x O 3 nanowire chemical vapor deposition mobility oxygen vacancy

Nanotube-Based chemical and Biomolecular Sensors

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 Materials Science & Technology 2008年第4期24卷 578-588页

作者： J.Koh B.Kim S.Hong H.Lim H.c.choi Department of Physics and Astronomy Seoul National University Shillim-Dong Kwanak-Gu Seoul 151-747 Korea Department of chemistry Pohang University of Science and Technology San 31 Hyoja-Dong Nam-Gu Pohang 790-784 Korea

We present a brief review about recent results regarding carbon nanotube （cNT）-based chemical and biomolecular sensors. For the fabrication of cNT-based sensors, devices containing cNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition （cVD） process or ＂surface programmed assembly＂ method. Then, the cNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive cNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.

关键词： chemical vapour deposition carbon nanotubes Sensors Biological molecules Surface programmed assembly

córdoba乳腺断层融合筛查试验（cBTST）乳腺筛查间期癌：乳腺断层融合联合数字乳腺摄影与单纯数字乳腺断层成像的比较

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2024年第5期 627-628页

作者： c.Pulido carmona S.Romero Martín J.L.Raya Povedano M.cara García P.Font Ugalde E.Elías cabot 张昕怡

目的比较数字乳腺断层摄影（DBT）+数字乳腺摄影（DM）与单纯DM筛查女性的乳腺筛查间期癌发病率及其特征的差异。方法比较córdoba乳腺断层融合筛查试验

关键词：

设计·领创·未来——专访2014欧特克AU中国“大师汇”传媒娱乐业资深专家

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国传媒科技 2014年第22期 74-76页

作者：曹素妨陈鑫胤 Marc stevens 谭伟康邓博弘欧特克公司欧特克公司大中华区 Dans点石数码

毫无疑问，设计与创新将是引领未来变革的核心动力。也许，十年前你还对数字化技术一头雾水，现如今，数字化技术已经遍布工作、生活甚至是产业的各个角落。数字化技术也让工程建设业、制造业和传媒娱乐业大放异彩。来自各行业的真知灼... 详细信息

毫无疑问，设计与创新将是引领未来变革的核心动力。也许，十年前你还对数字化技术一头雾水，现如今，数字化技术已经遍布工作、生活甚至是产业的各个角落。数字化技术也让工程建设业、制造业和传媒娱乐业大放异彩。来自各行业的真知灼见不但印证了设计领创未来的无限可能，也为开阔设计人员的创新思路，实现更多优秀创意产品的制作提供了极具价值的参考。对此，欧特克公司亚太地区及新兴市场高级副总裁兼传媒娱乐部高级副总裁魏柏德表示，承载着广大设计师厚爱的欧特克AU中国‘大师汇’将一如既往的为两岸三地的设计精英和行业专家搭建行业交流平台，让每个人都能够在这个开放的舞台上挥洒创意与灵感，“助力中国真正实现‘中国设计’‘中国创造’”。

关键词：传媒娱乐业设计人员行业专家中国大师数字化技术专访创新思路