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31.
This paper presents a model‐based adaptive control in task coordinates for robotic manipulators executing multilateral constrained tasks The controller works based on the concept of orthogonality between force and motion in the subspaces derived from the constraints. The control gains are independently adjustable in each subspace. The friction force, depending on the contact force, is compensated adaptively. Asymptotic convergence for both force and motion tracking errors is guaranteed by the Lyapunov‐Like Lemma. Experimental results obtained using a 3 D.O.F. robot are given. 相似文献
32.
We have studied the formation of bundles in mixtures of actin with the Dictyostelium 30 kDa actin-bundling protein as a function of 30 kDa protein concentration, actin concentration, and filament length. The presence of the 30 kDa protein promotes formation of filament bundles at actin concentrations and filament lengths that are not spontaneously aligned into liquid crystalline domains in the absence of the 30 kDa protein. Bundle formation in the presence of the 30 kDa protein was observed over a broad range of actin filament lengths and concentrations. Bundling was filament length dependent, and short filaments were more efficiently bundled. Bundles formed at actin concentrations as low as 2 microM. The volume fraction of the bundled portion and concentrations of actin and the 30 kDa protein in the bundled portion were measured using a sedimentation assay. Bundles have concentrations of actin and 30 kDa protein that are 10-20 and 5-20 times, respectively, greater than that of the bulk solution. Computer modeling reveals that bundling of actin by a bundling protein increases both the mean length and the polydispersity of the length distribution, factors which lower the actin concentration required for spontaneous alignment within the bundle. We propose that entropy-driven spontaneous ordering may contribute to bundle formation in two ways. Bundling of actin creates longer aggregates with a more polydisperse length distribution in which actin aligns spontaneously within the bundle at very low concentrations. In addition, bundling creates locally high concentrations of actin within these aggregates that will spontaneously align, providing an additional driving force for bundle ordering. 相似文献
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Out‐of‐Plane Strain Induced in a Moiré Superstructure of Monolayer MoS2 and MoSe2 on Au(111) 下载免费PDF全文
Satoshi Yasuda Ryosuke Takahashi Ryo Osaka Ryota Kumagai Yasumitsu Miyata Susumu Okada Yuhei Hayamizu Kei Murakoshi 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(31)
Making contact of transition metal dichalcogenides (TMDCs) with a metal surface is essential for fabricating and designing electronic devices and catalytic systems. It also generates strain in the TMDCs that plays significant role in both electronic and phonon structures. Therefore, detailed understanding of mechanism of the strain generation is important to fully comprehend the modulation effect for the electronic and phonon properties. Here, MoS2 and MoSe2 monolayers are grown on Au surface by chemical vapor deposition and it is demonstrated that the contact with a crystalline Au(111) surface gives rise to only out‐of‐plane strain in both MoS2 and MoSe2 layers, whereas no strain generation is observed on polycrystalline Au or SiO2/Si surfaces. Scanning tunneling microscopy analysis provides information regarding consequent specific adsorption sites between lower S (Se) atoms in the S? Mo? S (Se? Mo? Se) structure and Au atoms via unique moiré superstructure formation for MoS2 and MoSe2 layers on Au(111). This observation indicates that the specific adsorption sites give rise to out‐of‐plane strain in the TMDC layers. Furthermore, it also leads to effective modulation of the electronic structure of the MoS2 or MoSe2 layer. 相似文献
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Koreyoshi Imamura Kohshi Kinugawa Ryo Kagotani Mayo Nomura Kazuhiro Nakanishi 《Journal of food engineering》2012
Amorphous matrices made up of sugar molecules, are frequently used in food and pharmaceutical industries. A drawback to their use is that they are susceptible to collapse, as a result of water uptake and an increase in temperature and subsequently crystallize. Herein, the crystallization characteristics of amorphous sugar (sucrose and α-lactose) preparations were analyzed, with the purpose of obtaining knowledge that could lead to the prediction of how long the amorphous state is retained under various conditions. The impact of compression, physical aging and freezing rate on the induction period (tind) for crystallization were examined. Freeze-dried sugar samples were compressed at 74 or 443 MPa (5 min) and then rehumidified at specified RHs. Some freeze-dried sucrose samples were physically aged, and alternatively freeze-drying was conducted under different conditions. The isothermal crystallization of the prepared samples at different temperatures (T), the glass transition and the crystallization temperature (Tcry) were measured, using differential scanning calorimetry. The compression markedly decreased the tind, while significantly lowered the hygroscopicity. Physical aging and slower-freezing also shortened the tind. The tind was found to be correlated exclusively with (Tcry–T), regardless of rehumidification, compression, sugar type, physical aging and freezing rate in the freeze-drying process. 相似文献
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Shizue Furukawa Mikimasa Iwata Kazuo Adachi Tadashi Amakawa 《Electrical Engineering in Japan》2010,170(2):46-52
We investigated by numerical analysis the dependence of vaporization behavior of aluminum particles injected into transferred type arc plasma on injection conditions in synthesis of aluminum nitride ultra fine particles. On the basis of calculation results, we chose one proper injection condition where aluminum particles vaporized more. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(2): 46–52, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20852 相似文献
39.
Many studies have focused on the stabilization of additive manufacturing (AM) in microgravity for its use in various space projects. Nevertheless, this paper presents a vital clue for innovating metal AM technologies from the perspective of high gravity. High-gravitational powder bed fusion has an excellent potential to address various challenges in AM, such as density enhancement, spatter suppression, and precise fabrication. This study summarizes an analogy among phenomena in different gravitational fields and establishes a combined machine for centrifuge and powder bed fusion. The results confirm the spatter suppression and fine-powder availability in high gravity, both theoretically and experimentally. 相似文献
40.
Cationic polymerization behavior of β‐methylglycidyl ether derivatives and physical properties of their cationically cured materials 下载免费PDF全文
β‐Methylglycidyl ethers have been applied to Electrical and Electronic adhesives. However, there is no report about the detailed polymerization behavior and physical properties of their cured products. Hence, we investigated cationic polymerization behavior of bisphenol A di(β‐methylglycidyl) ether (Me‐BADGE) and physical properties of the cured products containing Me‐BADGE. DSC analysis suggested that Me‐BADGE could be cured completely at lower temperature than bisphenol A diglycidyl ether (BADGE). Physical properties were analyzed by dynamic viscoelastic analysis. Glass transition temperature (Tg) of BADGE homopolymer was 194°C. In contrast, the copolymer of BADGE (50 wt %) with Me‐BADGE (50 wt %) showed Tg at 124°C. According to the data of E’ and tan δ, crosslink density of the cured products decreased with increasing the Me‐BADGE content. The analysis of cationic polymerization of monofunctional β‐methylglycidyl ether suggested that the cationic polymerization proceeded not only through oxonium cation but also through carbocation formed by ring‐opening reaction of oxonium cation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42377. 相似文献