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1.
Noncommensurate 2D interfaces hold great promise toward low friction and nanoelectromechanical applications. For identical constituents, the crystals interlock at specific rotational configurations leading to high barriers for slide. In contrast, nonidentical constituents comprising different lattice parameters should enable robust superlubricity for all rotational configurations. This is however not the case for gold–graphite interfaces, as both theory and experiments show scaling behavior of the sliding force as a function of the interface contact area. By simulating the sliding force for gold–graphite interfaces, this work shows that the origin for high force barriers at special angular configurations is a result of commensurability between the moiré structure and the contact geometry. Consequently, this paper suggests new geometries that can potentially overcome such commensurability effects to enable robust superlubricity. 相似文献
2.
Scientometrics - This paper studies academic in-group bias in the top five economics journals. We examine citation counts for articles published in these journals during the years 2006–2015,... 相似文献
3.
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5.
In this article we examined aspects of negotiation within a persuasion framework. Specifically, we investigated how the provision of arguments that justified the first offer in a negotiation affected the behavior of the parties, namely, how it influenced counteroffers and settlement prices. In a series of 4 experiments and 2 pilot studies, we demonstrated that when the generation of counterarguments was easy, negotiators who did not add arguments to their first offers achieved superior results compared with negotiators who used arguments to justify their first offer. We hypothesized and provided evidence that adding arguments to a first offer was likely to cause the responding party to search for counterarguments, and this, in turn, led him or her to present counteroffers that were further away from the first offer. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
6.
We propose a novel framework for regularization of symmetric positive-definite (SPD) tensors (e.g., diffusion tensors). This
framework is based on a local differential geometric approach. The manifold of symmetric positive-definite (SPD) matrices,
P
n
, is parameterized via the Iwasawa coordinate system. In this framework distances on P
n
are measured in terms of a natural GL(n)-invariant metric. Via the mathematical concept of fiber bundles, we describe the tensor-valued image as a section where
the metric over the section is induced by the metric over P
n
. Then, a functional over the sections accompanied by a suitable data fitting term is defined. The variation of this functional
with respect to the Iwasawa coordinates leads to a set of
\frac12n(n+1)\frac{1}{2}n(n+1)
coupled equations of motion. By means of the gradient descent method, these equations of motion define a Beltrami flow over
P
n
. It turns out that the local coordinate approach via the Iwasawa coordinate system results in very simple numerics that leads
to fast convergence of the algorithm. Regularization results as well as results of fibers tractography for DTI are presented. 相似文献
7.
Yaniv Ganor Doron Shilo Nadege Zarrouati Richard D. James 《Sensors and actuators. A, Physical》2009,150(2):277-279
A new method for propulsion using a Ni2MnGa ferromagnetic shape memory flapper is introduced. We optically examine the magnetic field induced strain of pure shear by means of a state of the art generator that provides alternating magnetic fields of 7000 Oe at frequencies of up to 100 Hz. Preliminary measurements show local shear deformation of about 5%, which open new frontiers in propulsion mechanisms. 相似文献
8.
Itzhaq Azoulay Nataly Kucherenko Esther Nachliel Menachem Gutman Abdussalam Azem Yossi Tsfadia 《International journal of molecular sciences》2013,14(6):12675-12695
Hsp70 chaperones consist of two functional domains: the 44 kDa Nucleotide Binding Domain (NBD), that binds and hydrolyses ATP, and the 26 kDa Substrate Binding Domain (SBD), which binds unfolded proteins and reactivates them, utilizing energy obtained from nucleotide hydrolysis. The structure of the SBD of the bacterial Hsp70, DnaK, consists of two sub-domains: A β-sandwich part containing the hydrophobic cavity to which the hepta-peptide NRLLLTG (NR) is bound, and a segment made of 5 α-helices, called the “lid” that caps the top of the β-sandwich domain. In the present study we used the Escherichia coli Hsp70, DnaK, as a model for Hsp70 proteins, focusing on its SBD domain, examining the changes in the lid conformation. We deliberately decoupled the NBD from the SBD, limiting the study to the structure of the SBD section, with an emphasis on the interaction between the charges of the peptide with the residues located in the lid. Molecular dynamics simulations of the complex revealed significant mobility within the lid structure; as the structure was released from the forces operating during the crystallization process, the two terminal helices established a contact with the positive charge at the tip of the peptide. This contact is manifested only in the presence of electrostatic attraction. The observed internal motions within the lid provide a molecular role for the function of this sub-domain during the reaction cycle of Hsp 70 chaperones. 相似文献
9.
Parkinsonian behavioral deficits are reduced in the presence of strong eliciting stimuli and are most pronounced when the response requires internal generation. In the present study, rats' head entries into a food compartment were measured in the presence and absence of an eliciting stimulus. The D2 receptor blocker raclopride suppressed the emission of spontaneous head entries but did not slow head entries emitted in response to a food cue. Rats subjected to a pharmacological disruption in dopamine (DA) transmission show response impairments that are reduced, and in this case eliminated, in the presence of strong eliciting stimuli. The present results support the view that neuroleptic-induced reductions in DA transmission do not produce an absolute limit on the speed with which an individual response can be generated but that they reduce the likelihood of response generation in the absence of strong eliciting stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Ruth Osovsky Doron Kaplan Hadar Rotter Shai Kendler Michael Goldvaser Yossi Zafrani Ishay Columbus 《Carbon》2011,49(12):3899-3906
Thermal and hydrothermal degradations of adsorbed sulfur mustard (HD) on activated carbon particles from a chemical protective over-garment were studied. Carbon loaded with 5 wt.% HD was heated in a closed reactor at temperatures up to 160 °C for 0.5–6 h and analyzed by solid-state 13C MAS NMR. On dry carbon at room temperature, HD was stable for months. On a thoroughly pre-wetted carbon, adsorbed HD partially degraded to thiodiglycol (TDG) and TDG-sulfoxide (TDG-SO) within 2–3 months. Heating dry HD-loaded carbon to 160 °C caused partial degradation within 4 h to 1,4-thioxane, along with 1,4-dithiane and vinyl sulfides. Complete degradation within 2.5 h to the same products occurred upon hydrothermal treatment of the HD-loaded carbon, using a water/carbon ratio of 0.3:1. With higher water/carbon ratios of 0.6:1–5:1 at temperatures of 120 °C and above, adsorbed HD hydrolyzed rapidly within 0.5 h. The latter reaction led to the formation of TDG concurrent with either thioxane (at 160 °C) or TDG-SO and TDG-dimer (at 120 °C). The mechanisms of the observed degradation processes are discussed. 相似文献