Search results for "Prussia"

Estimation of individual Gibbs energies of cation transfer employing the insertion electrochemistry of solid Prussian blue

2011

Abstract A novel method to determine the Gibbs energy of cation transfer between two miscible solvents is described. This method uses electrochemical data for the reversible cation-assisted solid-state reduction of Prussian blue using ferrocene as internal potential standard. Voltammetric data can be used for a direct measurement of the Gibbs energy of ion transfer from one solvent to another using midpeak potentials in solutions of suitable salts in each one of the solvents separately or mixtures of the solvents. Excess Gibbs energies of solvation in solvent mixtures can also be directly estimated. Gibbs energies of cation transfer of Li+, Na+ and K+ ions from water to MeOH, MeCN and DMSO …

Vēsture: Sabiedrība, pārvalde un saimniecība Baltijas jūras reģionā no aizvēstures līdz jaunajiem laikiem

2012

Šajā LU Rakstu sējumā iekļautie raksti pamatojas gan uz referātiem, kas tikuši nolasīti 2008.–2010. gadā LU 66., 67. un 68. zinātniskās konferences Arheoloģijas, kā arī Viduslaiku un jauno laiku vēstures sekcijā, gan uz LU Vēstures un filozofijas fakultātes doktorantu pētījumiem. Raksti ir sadalīti divās daļās, kas, lai gan hronoloģiski pārklājas, tomēr atspoguļo dažādas vēstures jomas – pirmā krājuma daļa ir veltīta aktuāliem arheoloģiskiem pētījumiem, savukārt otrajā daļā iekļautie raksti pievēršas viduslaiku un jauno laiku vēstures problemātikai. Krājuma rakstos no dažādām pētnieciskām perspektīvām aplūkoti Baltijas jūras reģiona – pārsvarā Latvijas teritorijas (viena raksta gadījumā att…

Federico II di Prussia e la letteratura

2013

Corsican war and the diplomatic measures for the redemption of the prince of Paterno

2007

Photoinduced effects on the magnetic properties of the (Fe0.2Cr0.8)1.5[Cr(CN)6] Prussian blue analogue

2019

International audience; One of the most attractive characteristics of some Prussian blue derivatives is the sensitivity of their magnetic properties to the irradiation with light. In this work photoinduced effects in the (Fe0.2Cr0.8)1.5[Cr(CN)6]·15H2O PBA have been studied by means of X-ray-based spectroscopies and magnetometry. It is found that the photosensitivity of this compound is mostly centred on the Fe cations: the exposure to green light induces a transfer of electrons from them to the Cr that provokes a reversal of the previously existing linkage isomerization and increases the elastic strain caused by the misfit of the unit cells of the Fe–NC–Cr and Cr–NC–Cr sublattices. The gree…

Ziemie Prus w trakcie polskiej wojny sukcesyjnej i wojny siedmioletniej

2021

W trakcie licznych konfliktów zbrojnych rozegranych w osiemnastowiecznej Europie Prusy Wschodnie tylko raz były teatrem działań wojennych: latem 1757 r. – zimą 1758 r. Dwukrotnie jednak działania zbrojne toczyły się nad jej granicami, a w latach 1734-1735 przez prowincje pruską przechodziły transporty i oddziały walczących wojsk. Taka postawa nie przyniosła wówczas królowi pruskiemu żadnych korzyści, ale też uchroniła Prusy Wschodnie oraz jego mieszkańców przed ewentualnymi negatywnymi skutkami wojny na terytorium Rzeczpospolitej. Jednak ponad dwadzieścia lat później Prusy Wschodnie nie uniknęły już okrucieństw wojny. Król Fryderyk II atakiem w sierpniu 1756 r. na Saksonię chciał uprzedzić …

Enhancing the electrocatalytic activity and stability of Prussian blue analogues by increasing their electroactive sites through the introduction of …

2021

Prussian blue analogues (PBAs) have been proven as excellent Earth-abundant electrocatalysts for the oxygen evolution reaction (OER) in acidic, neutral and alkaline media. Further improvements can be achieved by increasing their electrical conductivity, but scarce attention has been paid to quantify the electroactive sites of the electrocatalyst when this enhancement occurs. In this work, we have studied how the chemical design influences the specific density of electroactive sites in different Au-PBA nanostructures. Thus, we have first obtained and fully characterized a variety of monodisperse core@shell hybrid nanoparticles of Au@PBA (PBA of NiIIFeII and CoIIFeII) with different shell siz…

Charge-transfer driven by ultrafast spin-transition in a CoFe Prussian blue analogue

2020

Photoinduced charge-transfer is an important process in nature and technology and is responsible for the emergence of exotic functionalities, such as magnetic order for cyanide-bridged bimetallic coordination networks. Despite its broad interest and intensive developments in chemistry and material sciences, the atomic-scale description of the initial photoinduced process, which couples intermetallic charge-transfer and spin transition, has been debated for decades; it has been beyond reach due to its extreme speed. Here we study this process in a prototype cyanide-bridged CoFe system by femtosecond X-ray and optical absorption spectroscopies, enabling the disentanglement of ultrafast electr…

The role of potassium and hydrogen ions in the Prussian Blue ⇆ Everitt's Salt process

1998

Cyclic voltammetry experiments have proved very useful in the knowledge and understanding of the role of the potassium and hydrogen ions during the Prussian Blue ⇄ Everitt's Salt process. While potassium ions act as a stoichiometric reactant, the hydrogen ions play a very important role in the kinetics of the electron-hopping process. The entropy change for the reaction PB ⇄ ES has proved to be dependent on the degree of crystallinity of the film, indicating that this entropy change is related to the fixation of inner counterions on the crystal structure of the films.

The correlation between electrochemical impedance spectra and voltammograms of PB films in aqueous NH4Cl and CsCl

1998

Abstract Voltammetric curves of reduction of Prussian Blue Films to the Everitt’s Salt form and oxidation to the Prussian Yellow form show important differences depending on the supporting electrolyte countercation. The rate of the overall electron-hopping depends on the countercation. Apparent diffusion coefficients are evaluated from impedance spectra at different stabilization potentials. The dependence of the apparent diffusion coefficients on the stabilization potential can help understand the dependence of the voltammograms shape on the countercation nature.