For domains in R d \mathbb {R}^d , d ≥ 2 d\geq 2 , we prove universal upper and lower bounds on the product of the bottom of the spectrum for the Laplacian to the power p > 0 p>0 and the supremum over all starting points of the p p -moments of the exit time of Brownian motion. It is shown that the lower bound is sharp for integer values of p p and that for p ≥ 1 p \geq 1 , the upper bound is asymptotically sharp as d → ∞ d\to \infty . For all p > 0 p>0 , we prove the existence of an extremal domain among the class of domains that are convex and symmetric with respect to all coordinate axes. For this class of domains we conjecture that the cube is extremal.
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This content will become publicly available on January 23, 2025
Deuteration of heptamethine cyanine dyes enhances their emission efficacy
We demonstrate that deuteration is a generally applicable strategy that leads to enhanced quantum yields of fluorescence, longer-lived singlet excited states and suppressed rates of non-radiative deactivation processes.
more » « less- PAR ID:
- 10489631
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 60
- Issue:
- 8
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 1000 to 1003
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Prosody is an important feature of language that conveys a wide range of information. However, prosody is widely considered to be a difficult domain of study within the language sciences. One consequence of this is that existing grammatical theories of prosody fail to explain prosodic choices that seem to arise from nonlinguistic cognitive demands, such as communicative context, top‐down expectations, and recent articulatory and acoustic experience. We provide an account of some of these phenomena and argue that linguistic theories that do not incorporate these factors into models of prosody are likely to mischaracterize its role in language.
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A free
Plain Language Summary can be found within the Supporting Information of this article. -
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Abstract This perspective piece discusses a set of attentional phenomena that are not easily accommodated within current theories of attentional selection. We call these phenomena attentional platypuses, as they allude to an observation that within biological taxonomies the platypus does not fit into either mammal or bird categories. Similarly, attentional phenomena that do not fit neatly within current attentional models suggest that current models are in need of a revision. We list a few instances of the “attentional platypuses” and then offer a new approach, that we term dynamically weighted prioritization, stipulating that multiple factors impinge onto the attentional priority map, each with a corresponding weight. The interaction between factors and their corresponding weights determines the current state of the priority map which subsequently constrains/guides attentional allocation. We propose that this new approach should be considered as a supplement to existing models of attention, especially those that emphasize categorical organizations.
This article is categorized under:
Psychology > Attention
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