Search results for "funktio"
showing 10 items of 319 documents
Thouless-Valatin moment of inertia and removal of the spurious mode in the linear response theory
2020
Symmetry breaking at the mean-field level leads to an appearance of a symmetry restoring Nambu-Goldstone (NG) mode in the linear response theory. These modes represent a special kind of collective motion of the system. However, they can interfere with the calculated intrinsic physical excitations and, hence, they are often called as spurious modes. I discuss translational and rotational NG mode and the inertia parameter associated with these modes, by using the finite amplitude method formalism. I will also discuss how to remove spurious mode from the calculated transition strength function.
Regularized pseudopotential for mean-field calculations
2019
We present preliminary results obtained with a finite-range two-body pseudopotential complemented with zero-range spin-orbit and density-dependent terms. After discussing the penalty function used to adjust parameters, we discuss predictions for binding energies of spherical nuclei calculated at the mean-field level, and we compare them with those obtained using the standard Gogny D1S finite-range effective interaction.
Mappings of exponentially integrable distortion: Decay of the Jacobian
2018
We establish an integrability result on the reciprocal of the Jacobian determinant for a mapping of exponentially integrable distortion and thus answer a question raised by S. Hencl and P. Koskela.
Fraktaalien luominen tietokoneella
2016
Tässä tutkielmassa esitellään muutamia tunnettuja menetelmiä Mandelbrotin ja Julian joukkojen ja iteroitujen funktiojärjestelmien luontiin. This paper presents some known methods for generating Mandelbrot and Julia sets and iterated function systems.
Historiallisen toimijuuden rakentuminen lukiolaisten esseevastauksissa
2018
Artikkelissa tarkastellaan historiallisen toimijuuden representoitumista osana tiedon rakentumista lukiolaisten kirjoittamissa dokumenttipohjaisissa esseissä. Tutkimuksen aineistona on 23 historian esseetä, joiden tehtävänantona on pohtia kylmän sodan aloittajaa annetun oheisaineiston valossa. Artikkelissa tekstitaitoja lähestytään sosiokulttuurisesti rakentuvina ja tiedonalakohtaisina taitoina. Esseiden kielen piirteiden tarkastelu sidotaan siis historian tiedonalan tiedonmuodostukseen sekä koulu-kontekstiin liittyviin piirteisiin.
 Artikkelin teoreettinen ja metodologinen viitekehys pohjautuu systeemis-funktionaaliseen kieliteoriaan. Historiallista toimijuutta lähestytään transitiivi…
Plasmon Excitations in Mixed Metallic Nanoarrays
2019
Features of the surface plasmon from macroscopic materials emerge in molecular systems, but differentiating collective excitations from single-particle excitations in molecular systems remains elusive. The rich interactions between single-particle electron-hole and collective electron excitations produce phenomena related to the chemical physics aspects within the atomic array. We study the plasmonic properties of atomic arrays of noble (Au, Ag, and Cu) and transition-metal (Pd, Pt) homonuclear chains using time-dependent density functional theory and their Kohn-Sham transition contributions. The response to the electromagnetic radiation is related to both the geometry-dependent confinement…
Atomically Precise, Thiolated Copper–Hydride Nanoclusters as Single-Site Hydrogenation Catalysts for Ketones in Mild Conditions
2019
Copper-hydrides are known catalysts for several technologically important reactions such as hydrogenation of CO, hydroamination of alkenes and alkynes, and chemoselective hydrogenation of unsaturated ketones to unsaturated alcohols. Stabilizing copper-based particles by ligand chemistry to nanometer scale is an appealing route to make active catalysts with optimized material economy; however, it has been long believed that the ligand-metal interface, particularly if sulfur-containing thiols are used as stabilizing agent, may poison the catalyst. We report here a discovery of an ambient-stable thiolate-protected copper-hydride nanocluster [Cu25H10(SPhCl2)18]3- that readily catalyzes hydrogen…
Charge Transfer Plasmons in Dimeric Electron Clusters
2020
The tunability of the optical response of dimers of metal clusters and nanoparticles makes them ideal for many applications from sensing and imaging to inducing chemical reactions. We have studied charge transfer plasmons in separate and linked dimers of closed-shell electron clusters of 8 and 138 electrons using time-dependent density functional theory. The simple model clusters enable the systematic study of the charge transfer phenomenon from the electronic perspective. To identify the charge transfer plasmons, we have developed an index, the Charge Transfer Ratio, for quantifying the charge transfer nature of the excitations. In addition, we analyze the induced transition density and th…
Density functional theory description of random Cu-Au alloys
2019
Density functional alloy theory is used to accurately describe the three core effects controlling the thermodynamics of random Cu-Au alloys. These three core effects are exchange correlation (XC), ...