Search results for "lek"
showing 10 items of 2808 documents
Control of Molecular Orbital Ordering Using a van der Waals Monolayer Ferroelectric
2022
Two-dimensional (2D) ferroelectric materials provide a promising platform for the electrical control of quantum states. In particular, due to their 2D nature, they are suitable for influencing the quantum states of deposited molecules via the proximity effect. Here, we report electrically controllable molecular states in phthalocyanine molecules adsorbed on monolayer ferroelectric material SnTe. In particular, we demonstrate that the strain and ferroelectric order in SnTe creates a transition between two distinct orbital orders in the adsorbed phthalocyanine molecules. By controlling the polarization of the ferroelectric domain using scanning tunneling microscopy (STM), we have successfully…
Controlling Exciton Propagation in Organic Crystals through Strong Coupling to Plasmonic Nanoparticle Arrays.
2022
Exciton transport in most organic materials is based on an incoherent hopping process between neighboring molecules. This process is very slow, setting a limit to the performance of organic optoelectronic devices. In this Article, we overcome the incoherent exciton transport by strongly coupling localized singlet excitations in a tetracene crystal to confined light modes in an array of plasmonic nanoparticles. We image the transport of the resulting exciton–polaritons in Fourier space at various distances from the excitation to directly probe their propagation length as a function of the exciton to photon fraction. Exciton–polaritons with an exciton fraction of 50% show a propagation length…
Time-linear scaling nonequilibrium Green's function method for real-time simulations of interacting electrons and bosons. II : Dynamics of polarons a…
2022
Nonequilibrium dynamics of the open chain Holstein-Hubbard model is studied using the linear time-scaling GKBA+ODE scheme developed in Pavlyukh et al. [Phys. Rev. B 105, 125134 (2022)]. We focus on the set of parameters relevant for photovoltaic materials, i.e., a pair of electrons interacting with phonons at the crossover between the adiabatic and antiadiabatic regimes and at moderately large electron-electron interaction. By comparing with exact solutions for two corner cases, we demonstrate the accuracy of the T matrix (in the pp channel) and the second-order Fan (GD) approximations for the treatment of electronic (e−e) and electron-phonon (e-ph) correlations, respectively. The feedback …
A conformationally adaptive macrocycle : conformational complexity and host–guest chemistry of zorb[4]arene
2018
Large amplitude conformational change is one of the features of biomolecular recognition and is also the basis for allosteric effects and signal transduction in functional biological systems. However, synthetic receptors with controllable conformational changes are rare. In this article, we present a thorough study on the host–guest chemistry of a conformationally adaptive macrocycle, namely per-O-ethoxyzorb[4]arene (ZB4). Similar to per-O-ethoxyoxatub[4]arene, ZB4 is capable of accommodating a wide range of organic cations. However, ZB4 does not show large amplitude conformational responses to the electronic substituents on the guests. Instead of a linear free-energy relationship, ZB4 foll…
Samtidskunst i skolen : En studie som inviterer elever til en konseptuell workshopspraksis
2019
Masteroppgave kunstfag KF500 - Universitetet i Agder 2019 Both from the elementary school education and the professional life, I have gained insight and an experience basis for commenting on the subject of arts and crafts. There are often techniques and crafts that are in focus. I miss howthe subject to a greater extentcanchallengestudent`s in critical thinking, playful exploration and reflection, especially with regards to visual art. This master thesis focuses on theseperspectives for teaching in the subject arts and crafts, and discuss contemporary art's place intheschool. The thesis can be viewed as a post in the discourse about the new curriculumforarts and crafts, scheduledtobe comple…
Molecular, Supramolecular Structures Combined with Hirshfeld and DFT Studies of Centrosymmetric M(II)-azido {M=Ni(II), Fe(II) or Zn(II)} Complexes of…
2021
The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]
Ammonia Activation by a Nickel NCN-Pincer Complex featuring a Non-Innocent N-Heterocyclic Carbene: Ammine and Amido Complexes in Equilibrium
2015
A Ni0-NCN pincer complex featuring a six-membered N-heterocyclic carbene (NHC) central platform and amidine pendant arms was synthesized by deprotonation of its NiII precursor. It retained chloride in the square-planar coordination sphere of nickel and was expected to be highly susceptible to oxidative addition reactions. The Ni0 complex rapidly activated ammonia at room temperature, in a ligand-assisted process where the carbene carbon atom played the unprecedented role of proton acceptor. For the first time, the coordinated (ammine) and activated (amido) species were observed together in solution, in a solvent-dependent equilibrium. A structural analysis of the Ni complexes provided insig…
Solvent directs the dimensionality of Cu-dicyanoimidazoles
2022
In this paper, we report one-pot reactions of the same reactants 4,5-dicyanoimidazole and CuI in different solvents. In pure MeCN, the reaction resulted in previously reported MOF structure [Cu(4,5-dicyanoimidazole)]n.(MeCN)0.5n (1). On the other hand, when MeCN/MeOH solvent mixture was used, a new coordination polymer [Cu(4,5-dicyanoimidazole)(MeCN)(CuI)]n (2) was formed. The crystallization yielded very different structures as determined by X-ray crystallography. In 1, the solvent molecule acetonitrile occupies the MOF pores via weak interactions, but in 2 it is coordinated to the metal center. Computational DFT calculations and topological charge density analysis were utilized to explore…
Pastāvīgā elektrokardiostimulatora implantācijas indikāciju prognostiskie faktori pēc transkatetra aortas vārstuļa implantācijas
2016
Ievads. Vadīšanas traucējumi pēc transkatetra aortas vārstuļa implantācijas (TAVI) ir bieži sastopami. Ar izmantotu CoreValve protēzi pastāvīgā elektrokardiostimulatora (EKS) implantācija ir līdz 40%. 3. pakāpes atrioventrikulāra (AV) blokāde pēc TAVI ir viens no sinkopes un pēkšņas kardiālas nāves iemesliem, kuru var novērst savlaicīgi implantējot pastāvīgo EKS. Pētījuma mērķis. Novērtēt pastāvīgā EKS implantācijas biežumu pacientiem pēc TAVI procedūras, tā saistību ar iespējamām izmaiņām elektrokardiogrammā, klīniskajiem un ehokardiogrāfiskajiem faktoriem pirms TAVI. Materiāli un metodes. Viena centra pētījumā retrospektīvi tika analizēti 58 pacientu dati, kuriem laika posmā no 2010.gada …
Effects of an Individualized Active Aging Counseling Intervention on Mobility and Physical Activity: Secondary Analyses of a Randomized Controlled Tr…
2020
Objectives: The aim of this study was to report preplanned secondary analyses of the effects of a 12-month individualized active aging counseling intervention on six mobility and physical activity outcomes. Methods: A two-arm, single-blinded randomized controlled trial was conducted among 75- and 80-year-old community-dwelling people. The intervention group (IG, n = 101) received counseling aimed at increasing self-selected, primarily out-of-home activity. The control group (CG, n = 103) received general health information. Data were analyzed with generalized estimating equations. Results: Physical performance improved in the IG more than that in the CG (group by time p = .022), self-repor…