Search results for "iTED"
showing 10 items of 2408 documents
Origin of the spin Seebeck effect in compensated ferrimagnets
2016
Magnons are the elementary excitations of a magnetically ordered system. In ferromagnets, only a single band of low-energy magnons needs to be considered, but in ferrimagnets the situation is more complex owing to different magnetic sublattices involved. In this case, low lying optical modes exist that can affect the dynamical response. Here we show that the spin Seebeck effect (SSE) is sensitive to the complexities of the magnon spectrum. The SSE is caused by thermally excited spin dynamics that are converted to a voltage by the inverse spin Hall effect at the interface to a heavy metal contact. By investigating the temperature dependence of the SSE in the ferrimagnet gadolinium iron garne…
A study of capillary discharge lamps in Ar–Hg and Xe–Hg mixtures
2011
Low-pressure capillary discharge lamps in Ar–Hg and Xe–Hg mixtures are studied. The discharge size is 0.5 mm (500 µm) in radius. According to the literature, such types of plasma sources are classified as microplasmas. The studies include spectrally resolved optical measurements, tomographic reconstructions and numerical simulations using the collisional–radiative model for an Ar–Hg plasma. We discuss the problems of theoretical modelling and experimental diagnostics of microplasma sources. It is shown that the conventional collisional–radiative model, based on the assumption that transportation of atoms in the highly excited states can be neglected, has limitations in modelling a capillary…
Prophylaxis In Congenital Factor VII Deficiency, Indications, Efficacy and Safety: Results of the STER
2010
Abstract Abstract 665 Introduction Prophylaxis is considered a difficult endeavour in FVII deficiency, especially because of the very short FVII zymogen and FVIIa half-lives, mainly in childhood. The Seven Treatment Evaluation Registry (STER, www.targetseven.org) is a prospective observational, multi-centre, web-based registry concerned with the evaluation of treatments for spontaneous bleeding episodes, surgery and prophylaxis in patients with FVII deficiency. As regards prophylaxis, STER provides the frame for a structured and detailed data capture aiming at: a) identifying patients in whom prophylaxis is advisable, b) defining clinical settings in which prophylaxis is necessary and c) de…
Ab initio SCF and CI calculations on the barrier to internal rotation of 1,3-butadiene
1972
Ab initio SCF and CI calculations employing a set of gaussian lobe functions have been carried out for the ground and excited states of five geometrical C4H6-structures occurring in the course of rotation from cis-butadiene to the trans-isomer. The rotational potential curves are discussed for the ground and excited states. Particularly the potential curve of the lowest triplet state is considered in this connection thereby substantiating quantitatively the proposed mechanism for induced dimerisation of C4H6. Possible assignments of the lowest singlet excited states in trans-butadiene are discussed.
Ultrafast internal conversion of excited cytosine via the lowest pipi electronic singlet state.
2003
Computational evidence at the CASPT2 level supports that the lowest excited state pipi* contributes to the S1/S0 crossing responsible for the ultrafast decay of singlet excited cytosine. The computed radiative lifetime, 33 ns, is consistent with the experimentally derived value, 40 ns. The nOpi* state does not play a direct role in the rapid repopulation of the ground state; it is involved in a S2/S1 crossing. Alternative mechanisms through excited states pisigma* or nNpi* are not competitive in cytosine.
Plants in the UK flower a month earlier under recent warming.
2022
Global temperatures are rising at an unprecedented rate, but environmental responses are often difficult to recognize and quantify. Long-term observations of plant phenology, the annually recurring sequence of plant developmental stages, can provide sensitive measures of climate change and important information for ecosystem services. Here, we present 419 354 recordings of the first flowering date from 406 plant species in the UK between 1753 and 2019 CE. Community-wide first flowering advanced by almost one month on average when comparing all observations before and after 1986 ( p < 0.0001). The mean first flowering time is 6 days earlier in southern than northern sites, 5 days earlier…
Calculation of excited-state properties using general coupled-cluster and configuration-interaction models.
2004
Using string-based algorithms excitation energies and analytic first derivatives for excited states have been implemented for general coupled-cluster (CC) models within CC linear-response (LR) theory which is equivalent to the equation-of-motion (EOM) CC approach for these quantities. Transition moments between the ground and excited states are also considered in the framework of linear-response theory. The presented procedures are applicable to both single-reference-type and multireference-type CC wave functions independently of the excitation manifold constituting the cluster operator and the space in which the effective Hamiltonian is diagonalized. The performance of different LR-CC/EOM-…
Large-scale calculations of excitation energies in coupled cluster theory: The singlet excited states of benzene
1996
Algorithms for calculating singlet excitation energies in the coupled cluster singles and doubles (CCSD) model are discussed and an implementation of an atomic-integral direct algorithm is presented. Each excitation energy is calculated at a cost comparable to that of the CCSD ground-state energy. Singlet excitation energies are calculated for benzene using up to 432 basis functions. Basis-set effects of the order of 0.2 eV are observed when the basis is increased from augmented polarized valence double-zeta (aug-cc-pVDZ) to augmented polarized valence triple-zeta (aug-cc-pVTZ) quality. The correlation problem is examined by performing calculations in the hierarchy of coupled cluster models…
Excited states of the water molecule: Analysis of the valence and Rydberg character
2008
The excited states of the water molecule have been analyzed by using the extended quantum-chemical multistate CASPT2 method, namely, MS-CASPT2, in conjunction with large one-electron basis sets of atomic natural orbital type. The study includes 13 singlet and triplet excited states, both valence and 3s-, 3p-, and 3d-members of the Rydberg series converging to the lowest ionization potential and the 3s- and 3p-Rydberg members converging to the second low-lying state of the cation, 1 math. The research has been focused on the analysis of the valence or Rydberg character of the low-lying states. The computation of the 1 math state of water at different geometries indicates that it has a predom…
Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods
2016
In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.