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991.
We investigated optical spectra of quasi-two-dimensional multiband systems. The extended Drude model analysis on the -plane optical conductivity spectra indicates that the effective mass should be enhanced near . Based on the sum rule argument, we showed that the orbital-selective Mott-gap opening for the bands, the widely investigated picture, could not be the origin of the mass enhancement. We exploited the multiband effects in the extended Drude model analysis, and demonstrated that the intriguing heavy mass state near should come from the renormalization of the band. 相似文献
992.
H.Y. Kwon M.J. Shin Y.J. Choi J.Y. Moon H.S. Ahn S.N. Yi S. Kim D.H. Ha S.H. Park 《Journal of Crystal Growth》2009,311(16):4146-4151
We fabricated one-dimensional GaN nanorods on AlN/Si (1 1 1) substrates at various temperatures, and carrier gas flow amount, using the hydride vapor phase epitaxy (HVPE) method. An AlN buffer layer of 50 nm thickness was deposited by RF sputtering for 25 min. Stalagmite-like GaN nanorods formed at a growth temperature of 650 °C. The diameters and lengths of GaN nanorods increase with growth time, whereas the density of nanorods decreases. And we performed the experiments by changing the carrier gas flow amount at a growth temperature of 650 °C and HCl:NH3 flow ratio of 1:40. GaN nanorods, with an average diameter of 50 nm, were obtained at a carrier gas flow amount of 1340 sccm. The shape, structures, and optical characteristics of the nanorods were investigated by field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence. 相似文献
993.
Seung Ki Moon Timothy W. Simpson Soundar R. T. Kumara 《Annals of Operations Research》2010,174(1):201-218
This paper introduces a methodology for knowledge discovery related to product family design that integrates an ontology with
data mining techniques. In the proposed methodology, the ontology represents attributes for the components of products in
functional hierarchies. Fuzzy clustering is employed for data mining to first partition product functions into subsets for
identifying modules in a given product family and then identify the similarity level of components in a module. Module categorization
is introduced to support association rule mining for knowledge discovery related to platform design. We apply the proposed
methodology to first develop and then utilize design knowledge for a family of power tools. Based on the developed design
knowledge, a new platform is suggested to improve commonality in the power tool family. 相似文献
994.
Roger?I.?TannerEmail author Christopher?Ness Arif?Mahmud Shaocong?Dai Jiyoung?Moon 《Rheologica Acta》2018,57(10):635-643
The role of friction in non-colloidal suspensions is examined with a model which splits the viscosity into a frictionless component (τ*) plus a frictional component which depends on the ratio of the particle pressure (P) to the shear stress (τ). The model needs the input by computation of τ* and P and a suitable choice of particle friction coefficient (μ). It can be extended to elongational flows and cases where sphere roughness is important; volume fractions up to 0.5 are considered. It is shown that friction acts in a feedback or “bootstrap” manner to increase the suspension viscosity. The analysis is also useful for deducing the friction coefficient in suspensions from experimental data. It was applied to several sets of experimental data and reasonable correlations of the viscosities were demonstrated. An example of the correlation for spheres in a silicone oil is shown for volume fractions 0.1–0.5. 相似文献
995.
贾宝路 胡钧 何建军 许世伟 H.Yamaguchi D.Kahl 马朋 苏俊 王宏伟 T.Nakao Y.Wakabayashi T.Teranishi K.I.Hahn J.Y.Moon H.S.Jung T.Hashimoto A.A.Chen D.Irvine C.S.Lee S.Kubono 《原子核物理评论》2019,36(1):37-42
14O (α,p)17F是天体X射线暴中重要的突破反应。本工作通过厚靶方法测量其逆反应1H (17F,α)14O的反应截面来研究这一关键反应。本实验工作是在日本东京大学原子核科学研究中心(CNS)的低能次级束流线(CRIB)上完成的,后续的扣除本底实验是在兰州放射性束流线(RIBLL1)上完成的。CRIB实验是通过2H (16O,n)17F转移反应产生17F次级束,经过CRIB分离提纯之后,利用该次级束轰击氢气靶。在氢气靶后布置了三套望远镜探测器系统,用以探测不同实验角度的反冲α粒子,在数据处理的过程中经过动力学重构后得到了1H (17F,α)14O反应在质心系能区Ec.m.=2.7~3.4 MeV的反应截面。实验结果在3 MeV以上的高能区与前人的薄靶实验数据是一致的,在低能区本工作获得了新的实验数据,倾向于支持干涉相消的理论预言结果。The 14O(α, p)17F reaction is one of the important breakout reactions in type I X-ray burst. This work reported a new cross section measurement of its reverse reaction of 1H(17F,α)14O. The experiment was performed using the CNS radioactive ion beam separator (CRIB), located at the Center for Nuclear Study (CNS), the University of Tokyo. The sequent background measurement was carried out at Radioactive Beam Line in Lanzhou (RIBLL1). 17F beam was produced via the transfer reaction of 2H(16O, n)17F, subsequently separated and purified by CRIB and bombarded a thick hydrogen H2 gas target. The recoiling α particles were measured by three △E-E silicon telescopes at three different angles. The total cross sections of 1H(17F,α)14O have been derived at Ec.m.=2.7~3.4 MeV based on an isotropic angular distribution assumption. Our results are consistent with the previous ones in the energy region of Ec.m.>3 MeV, and we also obtained some new data in the low energy region, which partly support the destructive interference between the direct and resonant reaction mechanism predicted by the theory. 相似文献
996.
Feng Chen Prakash Manandhar Md Salauddin Ahmed Shuai Chang Namuna Panday Haiqian Zhang Joong Ho Moon Jin He 《Macromolecular bioscience》2019,19(2)
In‐depth understanding of the biophysicochemical interactions at the nano–bio interface is important for basic cell biology and applications in nanomedicine and nanobiosensors. Here, the extracellular surface potential and topography changes of live cell membranes interacting with polymeric nanomaterials using a scanning ion conductance microscopy‐based potential imaging technique are investigated. Two structurally similar amphiphilic conjugated polymer nanoparticles (CPNs) containing different functional groups (i.e., primary amine versus guanidine) are used to study incubation time and functional group‐dependent extracellular surface potential and topographic changes. Transmembrane pores, which induce significant changes in potential, only appear transiently in the live cell membranes during the initial interactions. The cells are able to self‐repair the damaged membrane and become resilient to prolonged CPN exposure. This study provides an important observation on how the cells interact with and respond to extracellular polymeric nanomaterials at the early stage. This study also demonstrates that extracellular surface potential imaging can provide a new insight to help understand the complicated interactions at the nano–bio interface and the following cellular responses. 相似文献
997.
Shin Young Kang Chang Wan Kang Dong Wook Kim Yoon Myung Jaewon Choi Sang Moon Lee Hae Jin Kim Yoon‐Joo Ko Seung Uk Son 《化学:亚洲杂志》2019,14(18):3173-3180
The so‐called colloidal template synthesis has been applied to the preparation of surface‐engineered nanoadsorbents. Colloidal microporous organic network nanotemplates (C‐MONs), which showed a high surface area (611 m2 g?1) and enhanced microporosity, were prepared through the networking of organic building blocks in the presence of poly(vinylpyrrolidone) (PVP). Owing to entrapment of the PVP in networks, the C‐MONs showed good colloidal dispersion in EtOH. MoS2 precursors were incorporated into the C‐MONs and heat treatment afforded core–shell‐type C@MoS2 nanoparticles with a diameter of 80 nm, a negative zeta potential (?39.5 mV), a high surface area (508 m2 g?1), and excellent adsorption performance towards cationic dyes (qmax=343.6 and 421.9 mg g?1 for methylene blue and rhodamine B, respectively). 相似文献
998.
Frank E. Marshall Nicole Moon Thomas D. Persinger David J. Gillcrist Nelson E. Shreve William C. Bailey 《Molecular physics》2019,117(9-12):1351-1359
ABSTRACTThe microwave spectrum of 3-bromo-1,1,1,2,2-pentafluoropropane has been observed using CP-FTMW spectroscopy. Potential energy scans have been performed and confirm the existence of two conformers – trans and gauche – for which further structural optimisations and electric field gradient calculations have been performed in order to get highly accurate nuclear quadrupole coupling constants for assignment purposes. The combination of multiple conformers and large nuclear quadrupole coupling constants produce a very dense spectrum at an estimated 1?transition/MHz, near the continuum limit. This spectral density makes it necessary to have very sophisticated computational approaches in order to get geometric and electronic structures that are very close to experimental observation. Analysis of the spectrum allowed for the assignment of the trans conformer, but the gauche proved to be prohibitive, although it is believed to be present in the current spectrum. Full analysis of the rotational spectroscopic parameters of two isotopologues – the79Br and81Br – have been observed and are reported. Geometric analysis of the experimentally observed conformer is also reported using Kraitchman coordinate and second moments arguments. Further analysis of the spectrum reveals the occurrence of dipole-forbidden, nuclear quadrupole allowed transitions with one forbidden transition possessing the first known x-type forbidden transition linkage pathway. 相似文献
999.
Dmytro I. Danylchuk Seonah Moon Ke Xu Andrey S. Klymchenko 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15062-15066
Visualization of the nanoscale organization of cell membranes remains challenging because of the lack of appropriate fluorescent probes. Herein, we introduce a new design concept for super‐resolution microscopy probes that combines specific membrane targeting, on/off switching, and environment sensing functions. A functionalization strategy for solvatochromic dye Nile Red that improves its photostability is presented. The dye is grafted to a newly developed membrane‐targeting moiety composed of a sulfonate group and an alkyl chain of varied lengths. While the long‐chain probe with strong membrane binding, NR12A, is suitable for conventional microscopy, the short‐chain probe NR4A, owing to the reversible binding, enables first nanoscale cartography of the lipid order exclusively at the surface of live cells. The latter probe reveals the presence of nanoscopic protrusions and invaginations of lower lipid order in plasma membranes, suggesting a subtle connection between membrane morphology and lipid organization. 相似文献
1000.
Comparison of the effects of particle shape on thin FeSiCr electromagnetic wave absorber 总被引:2,自引:0,他引:2
Moon Suk Kim 《Journal of magnetism and magnetic materials》2009,321(6):581-585
The raw materials of FeSiCr were processed in the ball mill for 30 h and the shape of the FeSiCr particles was changed from sphere to flake type, which was observed using a scanning electron microscope. And FeSiCr composite microwave absorbers were mixed with silicone for mobile phones and the effects of the thickness of the samples on the absorption were measured using a network analyzer in order to investigate the relationship between the microwave absorption and the material constants. The flake-type FeSiCr-rubber composite showed high reflection loss, which was due to the high complex permittivity and permeability. Also, the matching frequency shifted toward lower frequency range with microwave absorber thickness, and the maximum reflection loss of −8.7 dB was observed in 1.85 GHz for a 1.6 mm thickness. 相似文献