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91.
Spatial Control of Substitutional Dopants in Hexagonal Monolayer WS2: The Effect of Edge Termination
Tianyi Zhang Mingzu Liu Kazunori Fujisawa Michael Lucking Kory Beach Fu Zhang Maruda Shanmugasundaram Andrey Krayev William Murray Yu Lei Zhuohang Yu David Sanchez Zhiwen Liu Humberto Terrones Ana Laura Elías Mauricio Terrones 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(6):2205800
The ability to control the density and spatial distribution of substitutional dopants in semiconductors is crucial for achieving desired physicochemical properties. Substitutional doping with adjustable doping levels has been previously demonstrated in 2D transition metal dichalcogenides (TMDs); however, the spatial control of dopant distribution remains an open field. In this work, edge termination is demonstrated as an important characteristic of 2D TMD monocrystals that affects the distribution of substitutional dopants. Particularly, in chemical vapor deposition (CVD)-grown monolayer WS2, it is found that a higher density of transition metal dopants is always incorporated in sulfur-terminated domains when compared to tungsten-terminated domains. Two representative examples demonstrate this spatial distribution control, including hexagonal iron- and vanadium-doped WS2 monolayers. Density functional theory (DFT) calculations are further performed, indicating that the edge-dependent dopant distribution is due to a strong binding of tungsten atoms at tungsten-zigzag edges, resulting in the formation of open sites at sulfur-zigzag edges that enable preferential dopant incorporation. Based on these results, it is envisioned that edge termination in crystalline TMD monolayers can be utilized as a novel and effective knob for engineering the spatial distribution of substitutional dopants, leading to in-plane hetero-/multi-junctions that display fascinating electronic, optoelectronic, and magnetic properties. 相似文献
92.
Masaru Miyayama Hiroya Terada Hiroaki Yanagida 《Journal of the American Ceramic Society》1981,64(1):19-C-
The metastable β form of bismuth sesquioxide was obtained by doping antimony oxide. The solubility of antimony was 4 to 10 at. %in β specimens, where more than 75% of the antimony atoms were valenced at 5+. 相似文献
93.
94.
Yasuo Suzuki Ryoetsu Yoshino Hisashi Saitoh Kazunori Fukushi Yoshikazu Sonehara 《Journal of Alloys and Compounds》1992,180(1-2):383-389
The mean molal activity coefficients of aqueous scandium chloride, nitrate, bromide and perchlorate solutions were determined at 25.0° for dilute to saturated concentrations, together with the activities of water. In the dilute solutions of scandium halides, the activity coefficients were obtained from electromotive force measurements on galvanic cells, and the osmotic coefficients of all four solutions above 0.1 mol kg−1 were determined from the isopiestic measurements. Least-squares equations were fitted to these coefficients, which were then used to calculate the mean molal activity coefficients and water activities. The relationships between these results and the corresponding activity data for other rare earth salts, and to the cation hydration and ionic interactions, are discussed. The results on scandium perchlorate solutions suggested that the inner-sphere hydration number of tervalent scandium ion may be seven. 相似文献
95.
Peng Mi Horacio Cabral Kazunori Kataoka 《Advanced materials (Deerfield Beach, Fla.)》2020,32(13):1902604
Development of drug-delivery systems that selectively target neoplastic cells has been a major goal of nanomedicine. One major strategy for achieving this milestone is to install ligands on the surface of nanocarriers to enhance delivery to target tissues, as well as to enhance internalization of nanocarriers by target cells, which improves accuracy, efficacy, and ultimately enhances patient outcomes. Herein, recent advances regarding the development of ligand-installed nanocarriers are introduced and the effect of their design on biological performance is discussed. Besides academic achievements, progress on ligand-installed nanocarriers in clinical trials is presented, along with the challenges faced by these formulations. Lastly, the future perspectives of ligand-installed nanocarriers are discussed, with particular emphasis on their potential for emerging precision therapies. 相似文献
96.
Tomoya Ohno Kazunori Numakura Hidenobu Itoh Hisao Suzuki Takeshi Matsuda 《Advanced Powder Technology》2011,22(3):390-395
This paper describes control of the coating layer thickness and the crystallite size of the core–shell hybrid particles by controlling the process parameter. The core–shell hybrid particles were prepared using liquid phase deposition (LPD). We confirmed that the homogeneous coating was attained from the result of the zeta potential and the transmission electron microscope (TEM) observation. Furthermore, the coating layer microstructure was estimated using Brunauer–Emmett–Teller (BET) method. The obtained coating layer of titania was estimated using the band gap energy. Results indicate that the blue shift of the band gap energy signifies that the physical property of the hybrid particles was controlled by the coating layer thickness and the crystallite size, which are determined by the processing parameters. 相似文献
97.
Digital image-based modeling applied to the homogenization analysis of composite materials 总被引:4,自引:0,他引:4
Absract The systematic methodologies to derive accurate microstructural models are developed for studying the mechanical behaviors
of composite materials. Since the geometric information of a microstructure is often given by an image or a set of images,
the direct interpretation of the geometry is possibly by digitizing it. By identifying each pixel or voxel with a finite element
(FE) and accompanying appropriate image processing, an FE model can be automatically generated. It is also emphasized that
the digitized models can be suitable for solving the FE equations by utilizing the uniformity of the FE mesh. The finite element
analysis (FEA) with the homogenization method enables the prediction the thermo-mechanical behavior of the periodic microstructure
(unit cell) as well as the global mechanical response of a structural component, while we are taking into account the specific
effect of the geometric structural configuration of the microstructure through digitization. Several kinds of the digitizing
techniques are presented to illustrate the potential of digital image-based (DIB) FE modeling of the unit cell. Keeping the
microstructural design in mind, the modification of the plane image is introduced and the virtual realization of the unit
cell geometry is presented so that a microstructural analysis utilizing the homogenization method would be realistic. 相似文献
98.
On the treatments of heterogeneities and periodic boundary conditions for isogeometric homogenization analysis 下载免费PDF全文
Seishiro Matsubara Shin‐Nosuke Nishi Kenjiro Terada 《International journal for numerical methods in engineering》2017,109(11):1523-1548
The treatments of heterogeneities and periodic boundary conditions are explored to properly perform isogeometric analysis (IGA) based on NURBS basis functions in solving homogenization problems for heterogeneous media with omni‐directional periodicity and composite plates with in‐plane periodicity. Because the treatment of the combination of different materials in IGA models is not trivial especially for periodicity constraints, the first priority is to clearly specify points at issue in the numerical modeling, or equivalently mesh generation, for IG homogenization analysis (IGHA). The most awkward, but important issue is how to generate patches for NURBS representation of the geometry of a rectangular parallelepiped unit cell to realize appropriate deformations in consideration of the convex‐hull property of IGA. The issue arises from the introduction of overlapped control points located at angular points in the heterogeneous unit cell, which must satisfy multiple point constraint (MPC) conditions associated with periodic boundary conditions (PBCs). Although two measures may be conceivable, we suggest the use of multiple patches along with double MPC that imposes PBCs and the continuity conditions between different patches simultaneously. Several numerical examples of numerical material and plate tests are presented to demonstrate the validity of the proposed strategy of IG modeling for IGHA. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
99.
Hideaki Fujita Kazunori ShimizuYuki Morioka Eiji Nagamori 《Journal of Bioscience and Bioengineering》2010,110(3):359-362
We have studied the effect of enhanced oxygen delivery by perfluorocarbons on the differentiation of C2C12 cells. The extent of differentiation was assessed by means of phase contrast/fluorescence microscopy, active tension measurement and the glucose consumption/lactate production rates. We found that enhanced oxygen delivery is suitable for full differentiation of C2C12 cells. 相似文献
100.
Bifurcation mechanism underlying echelon-mode formation 总被引:1,自引:0,他引:1
Kazuo Murota Kiyohiro Ikeda Kenjiro Terada 《Computer Methods in Applied Mechanics and Engineering》1999,170(3-4):423-448
This paper presents a theory on the underlying mathematical mechanism of the echelon mode (a series of parallel short wrinkles that looks like a flight of stairs or wild geese arranged in formation) which has been observed ubiquitously with uniform materials, but which has long denied successful numerical simulations. It is shown by means of the group-theoretic bifurcation theory that the echelon mode formation can be explained as a recursive (secondary, tertiary, …) symmetry-breaking bifurcation if O(2) × O(2) is chosen as the underlying symmetry to model the local uniformity of materials. This implies, for example, that the use of periodic boundaries is essential to successfully realize the oblique stripe patterns and the subsequent echelon mode formation in numerical simulations. In fact, a recursive bifurcation analysis of a rectangular domain with periodic boundaries subject to uniform uniaxial compression yields various kinds of patterns, such as diamond, stripe and echelon modes, which are often observed for materials under shear. 相似文献