289 research outputs found
Anderson localization of a Tonks-Girardeau gas in potentials with controlled disorder
We theoretically demonstrate features of Anderson localization in the
Tonks-Girardeau gas confined in one-dimensional (1D) potentials with controlled
disorder. That is, we investigate the evolution of the single particle density
and correlations of a Tonks-Girardeau wave packet in such disordered
potentials. The wave packet is initially trapped, the trap is suddenly turned
off, and after some time the system evolves into a localized steady state due
to Anderson localization. The density tails of the steady state decay
exponentially, while the coherence in these tails increases. The latter
phenomenon corresponds to the same effect found in incoherent optical solitons
Bose Hubbard Models with Synthetic Spin-Orbit Coupling: Mott Insulators, Spin Textures and Superfluidity
Motivated by the experimental realization of synthetic spin-orbit coupling
for ultracold atoms, we investigate the phase diagram of the Bose Hubbard model
in a non-abelian gauge field in two dimensions. Using a strong coupling
expansion in the combined presence of spin-orbit coupling and tunable
interactions, we find a variety of interesting magnetic Hamiltonians in the
Mott insulator (MI), which support magnetic textures such as spin spirals and
vortex and Skyrmion crystals. An inhomogeneous mean field treatment shows that
the superfluid (SF) phases inherit these exotic magnetic orders from the MI and
display, in addition, unusual modulated current patterns. We present a slave
boson theory which gives insight into such intertwined spin-charge orders in
the SF, and discuss signatures of these orders in Bragg scattering, in situ
microscopy, and dynamic quench experiments.Comment: 4 pages + references + supplementary inf
48. Influence of the Central Auditory Disorders on Behavior in Children with Hearing Loss Connected to Otitis Media with Effusion
Efficient passive network description of IC conducted emission models for model reduction
This article adresses the model reduction of IC conducted emission models. A method to efficiently deal with the high number of independent sources in IC conducted emission models, which are a strong limitation for model order reduction, is presented. A network alteration is proposed, which allows for a much higher model reduction than standard approaches. The system of the altered network can be more efficiently reduced with standard model order reduction algorithms in order to speed up frequency-simulations. Synthesising the reduced system into a passive electrical network enables fast time-simulations to be made with circuit simulators. The whole procedure is validated by reducing an example of an IC conducted emission model of an 32 Bit microcontroller.BMBF/01M 3169 ABMBF/01M 3169 DBMBF/01M 3169
Efficient modelling of IC conducted emission for power integrity analysis
In this paper two methodologies to reduce the complexity of IC conducted emission models for Power Integrity analysis in ICs are presented. The methodologies differ concerning the applicability in simulation tools, complexity and accuracy of the generated models. The first methodology uses a complex model and reduces its order to generate a model with a fewer number of elements. This methodology therefore involves a model order reduction approach. A second minimum complexity, module based modelling approach is introduced for rough estimations, as the order reduced model is still too complex for some applications. The two methodologies are applied to an IC conducted emission model of two digital modules of a 32 Bit microcontroller. The results of the three models are compared and discussed. Fields of application for the introduced modelling approaches are the estimation of the magnitude and time behaviour of the supply current as well as the determination of the number and position of the IC's supply pins.BMBF/01M 3169 ABMBF/01M 3169 DBMBF/01M 3169
Model order reduction of linear time invariant systems
This paper addresses issues related to the order reduction of systems with multiple input/output ports. The order reduction is divided up into two steps. The first step is the standard order reduction method based on the multipoint approximation of system matrices by applying Krylov subspace. The second step is based on the rejection of the weak part of a system. To recognise the weak system part, Lyapunov equations are used. Thus, this paper introduces efficient solutions of the Lyapunov equations for port to port subsystems.BMBF/01 M 3169
Primjena tehnologije rekombinantne DNA za pripravke kolinesteraza kao antidota i detektora organofosfata
To develop new avenues for synthesizing novel antidotes for organophosphate poisoning and for detection of the organophosphates, we have turned to recombinant DNA methods to synthesize cholinesterases with unusual properties. For antidotal therapy we describe mutations of the native mouse and human enzymes that allow for enhanced rates of oxime reactivation. Such enzymes, when localized in the circulation, would enable the circulating cholinesterase to become a catalytic rather than simply a stoichiometric scavenger. Hence, “oxime-assisted catalysis” provides a means for scavenging the organophosphates in the circulation thereby minimizing their tissue penetration and toxicity. Accordingly, the oxime antidote or prophylactic agent has a dual action within the circulation and at the tissue level. Second, through a novel chemistry, termed freeze-frame, click chemistry, we have used organophosphate conjugates of acetylcholinesterase as templates for the synthesis of novel nucleophilic reactivating agents. Finally, acetylcholinesterase can be modified through cysteine substitution mutagenesis and attachment of fluorophores at the substitution positions. When linked at certain locations in the molecule, the attached fluorophore is sensitive to organophosphate conjugation with acetylcholinesterase, and thus the very target of insecticide or nerve agent action becomes a detection molecule for organophosphate exposure.Razvijajući novi pristup sintezi antidota pri otrovanju organofosfatima kao i njihovu detekciju, primijenili smo metode rekombinantne DNA za pripremu kolinesteraza s neuobičajenim svojstvima. Za antidotsku terapiju istražili smo mutacije prirodnih enzima miša i čovjeka koje povećavaju brzine reaktivacije oksimom. Takvi enzimi bi po unosu u cirkulaciju postali katalitički, a ne samo stehiometrijski odstranjivači organofosfata. Na taj način “oksimom potpomognuta kataliza” omogućava čišćenje organofosfata iz cirkulacije umanjujući prodiranje organofosfata u tkiva i njihovu toksičnost. Prema tome, oksim kao antidot ima dvojaku ulogu: u cirkulaciji i na razini tkiva. S druge strane, uporabom novog sintetskog pristupa u oblikovanju biološki aktivnih spojeva poznatog kao “klik kemija” diskretnih proteinskih konformacija, organofosforilirani konjugati acetilkolinesteraze služe kao kalup u sintezi novih nukleofilnih reaktivatora. Naposljetku, acetilkolinesteraza se može mutagenezom modificirati uvo|enjem cisteina na koje se mogu vezati fluorofori. Fluorofori uvedeni na određena mjesta u molekuli acetilkolinesteraze mijenjaju svoja fluorescentna svojstva pri konjugaciji organofosfata s enzimom koji na taj način od objekta djelovanja insekticida i živčanih bojnih otrova postaje molekula za detekciju izloženosti organofosfatima
Exotic quantum spin models in spin-orbit-coupled Mott insulators
We study cold atoms in an optical lattice with synthetic spin-orbit coupling
in the Mott-insulator regime. We calculate the parameters of the corresponding
tight-binding model using Peierls substitution and "localized Wannier states
method" and derive the low-energy spin Hamiltonian for fermions and bosons. The
spin Hamiltonian is a combination of Heisenberg model, quantum compass model
and Dzyaloshinskii-Moriya interactions and it has a rich classical phase
diagram with collinear, spiral and vortex phases.Comment: 5 pages, 3 color figure
"General Domville": plovidba Saint John - Hong Kong - Split
U Zbirci likovnih radova Hrvatskoga pomorskog muzeja Split čuva se portret jedrenjaka koji je imao važnu ulogu u pomorskoj povijesti kanadske pokrajine New Brunswick. Godine 2009., kada je restaurirano to ulje na platnu, visine 44 cm i širine 59 cm, jedina poznata činjenica bila je to da prikazuje drveni trojarbolni jedrenjak imena „General Domville” te da se može datirati u drugu polovicu 19. stoljeća. Daljnja istraživanja s godinama su donijela dodatne informacije o putovanjima tog broda, no upravo je suradnja dviju muzejskih institucija tijekom pandemijske 2021. godine omogućila da se priča o „Generalu Domwilleu” konačno zaokruži. Slika jedrenjaka „General Domville” nije potpisana, ali ima veliku sličnost s djelima kineske škole, koja se bavila „portretiranjem” brodova. Istraživanja također pokazuju da ju je vjerojatno naslikao Pun Woo, koji je radio u Hong Kongu 1880-ih. Slika prikazuje „Generala Domvillea” gotovo punih jedara kako ulazi u luku Hong Kong s neidentificiranom zastavom na glavnom jarbolu (vjerojatno brodovlasnikovom) te s britanskom na stražnjem jarbolu. U pozadini desno vide se još neka plovila, uključujući kinesku džunku i parobrod na kotač
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