560 research outputs found
3- and 4-body Interactions from 2-body interactions in Spin Models: A Route to Abelian and Non-Abelian Fractional Chern Insulators
We describe a method for engineering local -body interactions
() from two-body couplings in spin- systems. When implemented
in certain systems with a flat single-particle band with a unit Chern number,
the resulting many-body ground states are fractional Chern insulators which
exhibit abelian and non-abelian anyon excitations. The most complex of these,
with , has Fibonacci anyon excitations; our system is thus capable of
universal topological quantum computation. We then demonstrate that an
appropriately tuned circuit of qubits could faithfully replicate this model up
to small corrections, and further, we describe the process by which one might
create and manipulate non-abelian vortices in these circuits, allowing for
direct control of the system's quantum information content.Comment: 4 pages + references and supplemental informatio
The decarboxylative Ireland-claisen rearrangemet : methodology studies and approaches to the total synthesis of (-) -suaveoline
This thesis is divided into three sections. Section one is a review of recent progress in the synthesis of macroline, sarpagine and ajmaline-related indole alkaloids. The review covers approximately the last ten years of published literature. Section two is divided into two parts and discusses the results of research into the decarboxylative Ireland-Claisen rearrangement. Part one gives the background to the project and discusses the mechanism of this rearrangement. The development of methodology for the synthesis of bifunctional rearrangement substrates is detailed. The competitive rearrangement of these bifunctional substrates is outlined and trends in reactivity are discussed. An account is given of the application of the decarboxylative Ireland-Claisen rearrangement to a cyclic malonate, which gave rise to a cyclopropane. Efforts towards a cyclic malonate substrate are detailed, including the use of carbon suboxide.
Part two concerns studies towards the total synthesis of (-)-suaveoline. The retrosynthetic analysis is explained and pertinent methodology introduced. The initial construction of a synthetically relevant rearrangement substrate is outlined. The reasons for the failure of this substrate to rearrange are discussed, as is the modified protecting group strategy that was adopted. Subsequent successful rearrangement and the synthesis of a key cyclopentenyl intermediate are described. Unsuccessful attempts to alkylate this cyclopentene are detailed and an alternative strategy is put forward. Novel methodology for the formation of pyridine-A/-oxides is disclosed and attempts to apply this to the synthesis of suaveoline are discussed. Section three is the experimental section, which gives detailed descriptions of the synthesis and spectroscopic characteristics of the compounds discussed in section two.Open acces
Mission Impossible: The Influence of Incumbent Industries on Mission-Oriented Innovation Policy Targeting Carbon Lock-In
In this paper, we explore how the power wielded by regional incumbents has impacted subnational innovation agendas. Our findings suggest that the design of mission-oriented innovation policies should be more attentive to regional innovation policies and their relationship to how innovation may serve to bolster incumbents and not undermine them. We use a case-study of innovation in fossil fuels.
Recently, innovation policy literature has explored innovation policy and global climate as a major topic. On the one hand, carbon lock-in has been used to explain why there has been such difficulty in reducing carbon emissions, in many cases, despite an increasing emphasis of mission-innovation policies. On the other hand, mission-innovation policies are believed to be a key to the development of disruptive innovations that could break this carbon intensive path dependency. Although the two literatures explore the same problem,
there could be more integration. While carbon lock-in is being considered in the mission- innovation literature, it nevertheless has been largely overlooked at the mission-setting stage. On the other hand, the lock-in literature has tended to overlook the findings of mission-oriented innovation literature in offering solutions, which suggests that there is
a more productive role for mission-oriented innovations in breaking free of previous constraints to serve in the low-carbon energy transition.
To make our case, we argue it is important to distinguish among the various impacts disruptive innovations have on the market shares of incumbents’. We propose the following three schema: new market, market rewarding and market destroying. By variegating the potential impact of innovations, we suggest that mission-oriented innovation polices may be designed to only support certain types of innovations that do not directly undermine the market share of incumbents.
Using a detailed case study of the Province of Alberta, Canada, we then explore the roleof the province’s mission-oriented policy in the development of technology to produce the Canadian oil sands. The case study illustrates how incumbents influenced the establishment and direction of the mission’s goal. Shifts in incumbency opposition toward the province’s mission-oriented innovation policy coincided with the changing impact of the innovation from being market destroying to market rewarding. We suggest that future researchshould be more attentive to the role of incumbents in influencing mission-oriented innovation policy and the importance of their influence at the mission-setting stage. Furthermore, we suggest that to meet the grand challenge of addressing climate change through mission-oriented innovation policies, these policies must be designed to break free of these institutional constraints
The rheology of saltwater taffy
Saltwater taffy, an American confection consisting of the main ingredients sugar, corn syrup, water, and oil, is known for its chewy texture and diverse flavors. We use a small amplitude oscillatory shear test to probe the linear viscoelastic properties of commercial taffy. At low frequencies, self-similar relaxation behavior characteristic of a critical gel is observed. The storage and loss moduli are power-law functions, with the same exponent, of the frequency. Such self-similarity arises from the distribution of air bubbles and oil droplets in the taffy, where air is incorporated and oil is emulsified through an iterative folding process known as “taffy-pulling.” Taffy obeys the time–temperature superposition principle. Horizontally shifting the dynamic moduli obtained at different temperatures yields a master curve at a chosen reference temperature. As a sufficiently high frequency is exceeded, taffy transitions from a critical gel-like state to an elastic solid-like state. The master curve can be described by the fractional Maxwell gel (FMG) model with three parameters: a plateau modulus, a characteristic relaxation time, and a power-law exponent. The master curves for taffy of different flavors can all be described by the FMG model with the same exponent, indicating that minor ingredients like flavorings and colorings do not significantly affect the rheology of taffy. Scaling the master curves with the plateau modulus and relaxation time results in their collapse onto a supermaster curve, hinting at a more fundamental time–temperature–taffy superposition principle. Guided by this principle, we hand-pull lab-made model taffies successfully reproducing the rheology of commercial taffy.journal articl
Mission Impossible: The Influence of Incumbent Industries on Mission-Oriented Innovation Policy Targeting Carbon Lock-In
In this paper, we explore how the power wielded by regional incumbents has impacted subnational innovation agendas. Our findings suggest that the design of mission-oriented innovation policies should be more attentive to regional innovation policies and their relationship to how innovation may serve to bolster incumbents and not undermine them. We use a case-study of innovation in fossil fuels.
Recently, innovation policy literature has explored innovation policy and global climate as a major topic. On the one hand, carbon lock-in has been used to explain why there has been such difficulty in reducing carbon emissions, in many cases, despite an increasing emphasis of mission-innovation policies. On the other hand, mission-innovation policies are believed to be a key to the development of disruptive innovations that could break this carbon intensive path dependency. Although the two literatures explore the same problem,
there could be more integration. While carbon lock-in is being considered in the mission- innovation literature, it nevertheless has been largely overlooked at the mission-setting stage. On the other hand, the lock-in literature has tended to overlook the findings of mission-oriented innovation literature in offering solutions, which suggests that there is
a more productive role for mission-oriented innovations in breaking free of previous constraints to serve in the low-carbon energy transition.
To make our case, we argue it is important to distinguish among the various impacts disruptive innovations have on the market shares of incumbents’. We propose the following three schema: new market, market rewarding and market destroying. By variegating the potential impact of innovations, we suggest that mission-oriented innovation polices may be designed to only support certain types of innovations that do not directly undermine the market share of incumbents.
Using a detailed case study of the Province of Alberta, Canada, we then explore the role
of the province’s mission-oriented policy in the development of technology to produce the Canadian oil sands. The case study illustrates how incumbents influenced the establishment and direction of the mission’s goal. Shifts in incumbency opposition toward the province’s mission-oriented innovation policy coincided with the changing impact of the innovation from being market destroying to market rewarding. We suggest that future research
should be more attentive to the role of incumbents in influencing mission-oriented innovation policy and the importance of their influence at the mission-setting stage. Furthermore, we suggest that to meet the grand challenge of addressing climate change through mission-oriented innovation policies, these policies must be designed to break free of these institutional constraints
The SINS Survey: Broad Emission Lines in High-Redshift Star-Forming Galaxies
High signal-to-noise, representative spectra of star-forming galaxies at z~2,
obtained via stacking, reveal a high-velocity component underneath the narrow
H-alpha and [NII] emission lines. When modeled as a single Gaussian, this broad
component has FWHM > 1500 km/s; when modeled as broad wings on the H-alpha and
[NII] features, it has FWHM > 500 km/s. This feature is preferentially found in
the more massive and more rapidly star-forming systems, which also tend to be
older and larger galaxies. We interpret this emission as evidence of either
powerful starburst-driven galactic winds or active supermassive black holes. If
galactic winds are responsible for the broad emission, the observed luminosity
and velocity of this gas imply mass outflow rates comparable to the star
formation rate. On the other hand, if the broad line regions of active black
holes account for the broad feature, the corresponding black holes masses are
estimated to be an order of magnitude lower than those predicted by local
scaling relations, suggesting a delayed assembly of supermassive black holes
with respect to their host bulges.Comment: 11 pages, 5 figures. Accepted version, incorporating referee
comments, including changes to title, abstract, figures, and discussion
sectio
Современные исследования по социальной истории Беларуси (по материалам исторической научной периодики 1991–2014 гг.)
Материалы XI Междунар. науч. конф. студентов, аспирантов и молодых ученых, Гомель, 17-18 мая 2018 г
Whole Genome Sequencing of a Methicillin-Resistant Staphylococcus aureus Pseudo-Outbreak in a Professional Football Team.
Two American football players on the same team were diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections on the same day. Our investigation, including whole genome sequencing, confirmed that players did not transmit MRSA to one another nor did they acquire the MRSA from a single source within the training facility
Ebookness
Since the mid-2000s, the ebook has stabilized into an ontologically distinct form, separate from PDFs and other representations of the book on the screen. The current article delineates the ebook from other emerging digital genres with recourse to the methodologies of platform studies and book history. The ebook is modelled as three concentric circles representing its technological, textual and service infrastructure innovations. This analysis reveals two distinct properties of the ebook: a simulation of the services of the book trade and an emphasis on user textual manipulation. The proposed model is tested with reference to comparative studies of several ebooks published since 2007 and defended against common claims of ebookness about other digital textual genres
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