Search results for "classical"
showing 10 items of 2294 documents
Multireference equation-of-motion coupled cluster theory.
2012
A generalization of the equation-of-motion coupled cluster theory is proposed, which is built upon a multireference parent state. This method is suitable for a number of electronic states of a system that can be described by similar active spaces, i.e., different linear combinations of the same set of active space determinants. One of the suitable states is chosen as the parent state and the dominant dynamical correlation is optimized for this state using an internally contracted multireference coupled cluster ansatz. The remaining correlation and orbital relaxation effects are obtained via an uncontracted diagonalization of the transformed Hamiltonian, Ĥ = e(-T) Ĥe(T), in a compact multire…
Extending Limits of Chlorine Kinetic Isotope Effects
2012
Chlorine kinetic isotope effects exceeding semiclassical limits were observed in enzyme-catalyzed reactions, but their source has not been yet identified. Herein we show that unusually large chlorine kinetic isotope effects are associated with reactions in which chlorine is the central atom that is being passed between two heavy atoms. The origin of these large values is the ratio of imaginary frequencies for light-to-heavy species (the so-called temperature-independent factor).
Stability of melt flow due to a traveling magnetic field in a closed ampoule
2004
The linear three-dimensional instability of the flow due to a low frequency traveling magnetic field in a regular cylinder is studied numerically for height-to-diameter ratios in the range [0.5:2.5]. The first instability has the form of an azimuthal wave with wave numbers between 1 and 6 depending on the aspect ratio. It is shown that the flow is stable if the Reynolds number is below 290. Even stronger stationary flows may be obtained in a flattened cylinder.
Elastohydrodynamic Collision of Two Spheres Allowing Slip on Their Surfaces.
2000
Our goal is to study theoretically the effect of deformation on the collision of two solid spheres allowing slip on their surfaces. The deformed shape of the solid surface is determined via an asymptotic technique assuming that deformation is small compared with the separation between the surfaces. It has previously been shown that the slippage makes collision possible even without any surface attractive force. Here we demonstrate that even a small amount of deformation can preclude spheres from coagulation. Copyright 2000 Academic Press.
Emotion regulation strategies modulate the effect of adverse childhood experiences on perceived chronic stress with implications for cognitive flexib…
2020
Exposure to early life adversity is associated with chronic stress and a range of stress-related health problems in adulthood. Since chronic stress debilitates activity in the prefrontal cortex (pFC), maladaptive regulatory strategies in response to stress have been proposed as one explanation for the impact of early life adversity on health outcomes in adulthood. We conducted a study to examine the impact of adverse childhood experiences (ACEs) on cognitive flexibility, a key executive function implicated in activity in the pFC, in a sample of adults (N = 486). Additionally, we investigated whether perceptions of chronic stress in adulthood would mediate the influence of ACEs on cognitive …
Autobiogrāfiskie motīvi ķīniešu imperatoru dzejā (no Haņ līdz Cjin dinastijai)
2021
Bakalaura darbā “Autobiogrāfiskie motīvi ķīniešu imperatoru dzejā (no Haņ līdz Cjin dinastijai)” tiek analizēta ievērojamāko ķīniešu Haņ līdz Cjin dinastiju imperatoru-literātu dzeja un tajā esošas autobiogrāfiskas iezīmes. Bakalaura darba mērķis ir iepazīstināt ar dažādu dinastiju (no Haņ līdz Cjin dinastijai) ķīniešu imperatoru dzīvēm, kuru dzeja ir saglabājusies līdz mūsdienām. Galvenie uzdevumi ir apskatīt viņu rakstīšanas stilus un to īpašības; izpētīt vēstures fonu un dzejas attīstību katrā no darbā minētajām dinastijām, lai noskaidrotu imperatoru dzejas saistību ar valsts un viņu personīgās dzīves notikumiem, kā arī izvēlēties, tulkot no senķīniešu valodas un analizēt nozīmīgākos dze…
CHIRAL ANOMALY IN ASHTEKAR'S APPROACH TO CANONICAL GRAVITY
1998
The Dirac equation in Riemann–Cartan spacetimes with torsion is reconsidered. As is well-known, only the axial covector torsion A, a one-form, couples to massive Dirac fields. Using diagrammatic techniques, we show that besides the familiar Riemannian term only the Pontrjagin type four-form dA ∧ dA does arise additionally in the chiral anomaly, but not the Nieh–Yan term d* A, as has been claimed recently. Implications for cosmic strings in Einstein–Cartan theory as well as for Ashtekar's canonical approach to quantum gravity are discussed.
Synthesis and characterization of diatomaceous earth chemically modified with γ-aminopropyltrimethoxysilane
2003
A stationary phase for thin-layer chromatography has been prepared by bonding purified diatomaceous earth (rich in silica) with γ-aminopropyltrimethoxysilane. The phase has been characterized by elemental analysis, measurement of the specific surface area, IR spectroscopy, thermal analysis, and chromatographic testing.
A Simple Technique for Measuring Leucocyte Chemotaxis in Reversible Boyden Chambers
1977
A technique for assay of leucocyte chemotaxis in Boyden chambers is described. A set of up to 12 closed chambers with 2 compartments is formed from commercially available migration plates. The set can be turned during the incubation and thus the detachment of cells from the filter, a major source of variation in classical type of chambers, can be prevented. The technique is simple and so inexpensive that it allows the use of the material as disposable if preferred.
Diurnal changes in the perception of emotions in music: Does the time of day matter?
2014
According to the Hindustani music tradition, the ability of a song to induce certain emotions depends on the time of day: playing a song at the right time is said to maximise its emotional effect. The present exploratory study investigated this claim by combining findings in chronobiology, mood research and music perception. It has already been established that some aspects of our mood fluctuations follow a cyclical pattern. Besides, it is a known fact that our current mood influences our perception and assessment of emotions. However, these elements have never been linked together in a study examining the effect of mood cyclicity on perceived emotions in music. To test the hypothesis of a…