scholarly journals Селективное возбуждение и создание инверсной населенности в квантовых системах с помощью униполярных аттосекундных и терагерцовых импульсов

2020 ◽  
Vol 128 (12) ◽  
pp. 1905
Author(s):  
Р.М. Архипов ◽  
М.В. Архипов ◽  
А.В. Пахомов ◽  
М.О. Жукова ◽  
А.Н. Цыпкин ◽  
...  
Keyword(s):  
Strong Field ◽  
Energy Levels ◽  
Weak Field ◽  
Quantum Systems ◽  
Spatial Profile ◽  
Terahertz Pulses ◽  
Selective Population ◽  
Dynamics Of Population ◽  
The Impact ◽  
Level Medium

The possibility of selective population of the energy levels of quantum systems was studied using a single unipolar subcycle pulse and a pair of pulses. Selective population of quantum levels is clearly illustrated based on the numerical solution of the system of equations for the density matrix of a three-level medium interacting with a pair of subcycle attosecond and terahertz pulses. The possibility of creating an population inversion in a three-level medium is shown using a pair of such pulses. The dynamics of population density gratings in a three-level medium is studied at the impact on the system of a pair of large-amplitude Gaussian pulses. If in a weak field the shape of the gratings is harmonic, according to analytical calculations performed according to perturbation theory, then in in the case of a strong field, the spatial profile of the gratings can differ from the sinusoidal one and has complex spike structure.

Crystal field spectra of d3,7 ions. VI. The weak field formalism and covalency

1970 ◽  
Vol 23 (5) ◽  
pp. 861 ◽  
Author(s):  
J Ferguson ◽  
DL Wood
Keyword(s):  
Crystal Field ◽  
Strong Field ◽  
Energy Levels ◽  
Outer Part ◽  
Weak Field ◽  
Field Energy ◽  
Electrostatic Repulsion ◽  
Crystal Field Theory ◽  
Free Ion ◽  
Field Formalism

When the problem of an ion in a crystal field is solved using the unperturbed atomic wave functions as basis functions, the free ion energies appear explicitly in the diagonal terms of the secular determinant where they can be adjusted as experimental parameters. By fitting the observed crystal field energy levels in this scheme, a set of modified free ion energy levels can be derived for Dq = 0, and it is found that in most cases a single set of electrostatic repulsion parameters F2 and F4 describes the energies, provided a Trees correction is applied. The values of F2 and F4 obtained in this way from crystal spectra of Cr3+ in ruby, yttrium gallium garnet, other oxides, and K3Cr(CN)6 and of Co2+ in ZnAl2O4 are reduced by covalency from their free ion values. The reduction for P2 is greater than for F4 because of its greater sensitivity to the outer part of the radial distribution function, where covalency plays its major part. It is concluded that the differential expansion of the t2 and e orbitals in the crystal field is not great, and that nephelauxetic effects in crystal field spectra should more properly be related to the F2 and F4 parameters of Condon and Shortley through the weak field formalism, rather than to Racah's B parameter in the strong field approach. The latter results in unsound conclusions about the effects of covalency. Analysis of the spectra of CrBrs and C0C14" suggests that the d electrons are not adequately described by two electrostatic repulsion parameters and the usual crystal field theory should be applied cautiously.

scholarly journals Adjustment of Whey:Casein Ratio from 20:80 to 60:40 in Milk Formulation Affects Food Intake and Brainstem and Hypothalamic Neuronal Activation and Gene Expression in Laboratory Mice

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 658
Author(s):  
Erin L. Wood ◽  
David G. Christian ◽  
Mohammed Arafat ◽  
Laura K. McColl ◽  
Colin G. Prosser ◽  
...  
Keyword(s):  
Food Intake ◽  
Area Postrema ◽  
Energy Levels ◽  
Early Gene ◽  
Hypothalamic Nucleus ◽  
Laboratory Mice ◽  
Neuronal Activation ◽  
Short Term ◽  
Animal Milk ◽  
The Impact

Adjustment of protein content in milk formulations modifies protein and energy levels, ensures amino acid intake and affects satiety. The shift from the natural whey:casein ratio of ~20:80 in animal milk is oftentimes done to reflect the 60:40 ratio of human milk. Studies show that 20:80 versus 60:40 whey:casein milks differently affect glucose metabolism and hormone release; these data parallel animal model findings. It is unknown whether the adjustment from the 20:80 to 60:40 ratio affects appetite and brain processes related to food intake. In this set of studies, we focused on the impact of the 20:80 vs. 60:40 whey:casein content in milk on food intake and feeding-related brain processes in the adult organism. By utilising laboratory mice, we found that the 20:80 whey:casein milk formulation was consumed less avidly and was less preferred than the 60:40 formulation in short-term choice and no-choice feeding paradigms. The relative PCR analyses in the hypothalamus and brain stem revealed that the 20:80 whey:casein milk intake upregulated genes involved in early termination of feeding and in an interplay between reward and satiety, such as melanocortin 3 receptor (MC3R), oxytocin (OXT), proopiomelanocortin (POMC) and glucagon-like peptide-1 receptor (GLP1R). The 20:80 versus 60:40 whey:casein formulation intake differently affected brain neuronal activation (assessed through c-Fos, an immediate-early gene product) in the nucleus of the solitary tract, area postrema, ventromedial hypothalamic nucleus and supraoptic nucleus. We conclude that the shift from the 20:80 to 60:40 whey:casein ratio in milk affects short-term feeding and relevant brain processes.

Rupture by impact-induced fatigue of a copper foil strip embedded in a multifunctional composite material

2021 ◽  
pp. 002199832199432
Author(s):  
Yacine Ouroua ◽  
Said Abdi ◽  
Imene Bachirbey
Keyword(s):  
Composite Material ◽  
Mechanical Characteristics ◽  
Glass Fibers ◽  
Energy Levels ◽  
Fatigue Tests ◽  
Repeated Impact ◽  
Aeronautical Industry ◽  
Repeated Impacts ◽  
Cracking Mode ◽  
The Impact

Multifunctional composite materials are highly sought-after by the aerospace and aeronautical industry but their performance depends on their ability to sustain various forms of damages, in particular damages due to repeated impacts. In this work we studied the mechanical behavior of a layered glass-epoxy composite with copper inserts subjected to fatigue under repeated impacts with different energy levels. Damage evolution as a function of impact energy was carefully monitored in order to determine the effect of the copper inserts on mechanical characteristics of the multifunctional composite, such as endurance and life. Results of repeated impact tests show that electric current interruption in the copper inserts occurs prior to the total perforation of the composite material, and after about 75% of the total number of impacts to failure. This is the case for the three energy levels considered in this study, [Formula: see text] = 2, 3 and 4 Joules. The epoxy resin was dissolved chemically in order to preserve the mechanical structure of the damaged copper inserts and the composite fibers for further inspection and analysis. Scanning electron microscopy (SEM) of the fractured copper inserts revealed interesting information on the nature of the damage, including information on plastic deformation, strain hardening, cracking mode, temperature increase during the impacts, and most importantly the glass fibers and their roles during the impact-fatigue tests.

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

Ligand Field-Spin Orbit Energy Levels in the d4 and d6 Electron Configurations of Octahedral and Tetrahedral Symmetry

1974 ◽  
Vol 29 (1) ◽  
pp. 31-41 ◽  
Author(s):  
E. König ◽  
S. Kremer
Keyword(s):  
Strong Field ◽  
Energy Levels ◽  
Coulomb Repulsion ◽  
Orbit Interaction ◽  
Complete Agreement ◽  
Ligand Field ◽  
Spin Orbit ◽  
Tetrahedral Symmetry ◽  
Spin Orbit Interaction ◽  
Orbit Perturbation

The complete ligand field -Coulomb repulsion -spin orbit interaction matrices have been derived for the d4 and d6 electron configurations within octahedral (Oh) and tetrahedral (Td) symmetry. The calculations were perform ed in both the weak-field and strong-field coupling schemes and complete agreement of the results was achieved. The energy matrices are parametrically dependent on ligand field (Dq), Coulomb repulsion (B, C) and spin-orbit interaction (ζ). Correct energy diagrams are presentend which display the splittings by spin-orbit perturbation as well as the effect of configuration mixing. Applications to the interpretation of optical spectral data, to the detailed behavior at the crossover of ground terms, and to complete studies in magnetism are pointed out.

scholarly journals Opacities in Strong Magnetic Helds

1995 ◽  
Vol 10 ◽  
pp. 588-590
Author(s):  
Dayal T. Wickramasinghe
Keyword(s):  
Entire Range ◽  
White Dwarfs ◽  
Specific Problem ◽  
Transition Probabilities ◽  
Strong Field ◽  
Energy Levels ◽  
Dipolar Field ◽  
Origin And Evolution ◽  
End Products ◽  
Hydrogen Lines

White dwarfs are one of the most readily studied end products of stellarevolution. Their observed properties have provided and continue to provide important constraints for the theory of stellar evolution. Likewise, a study of magnetism in white dwarfs provides unique insights into the origin and evolution of magnetic fields in stars.Spectacular progress has been made on the specific problem of the structure of the hydrogen atom in strong fields. Energy levels and transition probabilities are now known for all low lying states of hydrogen for the entire range of field strengths appropriate to white dwarfs and neutron stars (104-1013G) (Rosner et al 1984, Forster et al 1984 and Henry and O’Connell 1984). These calculations resulted in the identification of spectral features in the magnetic white dwarf Grw+70°8247 which had remained unidentified for over 50 years (Minkowski 1938), with Zeeman shifted hydrogen lines in a magnetic field of 100 -320 MG ((eg Wickamasinghe and Ferrano 1989). Several other strong field magnetic white dwarfs have since been discovered through hydrogen Zeeman spectroscopy. The data presently at hand show that most hydrogen rich magnetic white dwarfs have complex non-dipolar field structures with strong evidence for higher order multipole components.

scholarly journals Terahertz quantum plasmonics at nanoscales and angstrom scales

Nanophotonics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 435-451 ◽  
Author(s):  
Taehee Kang ◽  
Young-Mi Bahk ◽  
Dai-Sik Kim
Keyword(s):  
Electron Tunneling ◽  
Strong Field ◽  
Field Enhancement ◽  
Dipole Antenna ◽  
Strong Light ◽  
Metallic Structures ◽  
Terahertz Pulses ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Quantum Phenomena

AbstractThrough the manipulation of metallic structures, light–matter interaction can enter into the realm of quantum mechanics. For example, intense terahertz pulses illuminating a metallic nanotip can promote terahertz field–driven electron tunneling to generate enormous electron emission currents in a subpicosecond time scale. By decreasing the dimension of the metallic structures down to the nanoscale and angstrom scale, one can obtain a strong field enhancement of the incoming terahertz field to achieve atomic field strength of the order of V/nm, driving electrons in the metal into tunneling regime by overcoming the potential barrier. Therefore, designing and optimizing the metal structure for high field enhancement are an essential step for studying the quantum phenomena with terahertz light. In this review, we present several types of metallic structures that can enhance the coupling of incoming terahertz pulses with the metals, leading to a strong modification of the potential barriers by the terahertz electric fields. Extreme nonlinear responses are expected, providing opportunities for the terahertz light for the strong light–matter interaction. Starting from a brief review about the terahertz field enhancement on the metallic structures, a few examples including metallic tips, dipole antenna, and metal nanogaps are introduced for boosting the quantum phenomena. The emerging techniques to control the electron tunneling driven by the terahertz pulse have a direct impact on the ultrafast science and on the realization of next-generation quantum devices.

Impact of adding plinabulin to pegfilgrastim for the prevention of TAC chemotherapy (Chemo) induced neutropenia (CIN), on patient quality of life (QoL).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e24031-e24031
Author(s):  
Ramon Mohanlal ◽  
Yvette Lelorier ◽  
Dominic Mitchell ◽  
Lan Huang ◽  
Douglas W. Blayney
Keyword(s):  
Clinical Trial ◽  
Energy Levels ◽  
Breast Cancer Patients ◽  
Emotional Wellbeing ◽  
Phase 3 ◽  
Tac Chemotherapy ◽  
Physical Wellbeing ◽  
The Impact ◽  
Clinical Trial Information

e24031 Background: Plinabulin is a novel non-G-CSF small molecule being developed for the prevention of chemotherapy in conjunction with pegfilgrastim and is administered via 30 min IV infusion, 30 min after chemo on Day (D) 1. The QoL was analyzed using the Functional Assessment of Cancer Therapy - General questionnaire (FACT-G) as part of a phase 3 (Ph3) clinical trial comparing pegfilgrastim alone versus pegfilgrastim and plinabulin for the prevention of neutropenia in newly diagnosed breast cancer patients being treated with Docetaxel (75 mg/m2), Doxorubicin (50 mg/m2), and Cyclophosphamide (500 mg/m2) (TAC) on D1 for four 21 D cycles and study treatment. Methods: The FACT-G was administered to patients in China and Ukraine using an ePRO app downloaded onto patients' phones as part of the Phase 3 PROTECTIVE-2 trial (NCT0329457) with TAC. Patients completed the FACT-G during each chemo cycle at D-1, D1, D8 and D15. Patients received reminders 1 hour before the required completion time and all entries were time stamped. The FACT-G measured the impact of cancer on four categories: Physical wellbeing, Social wellbeing, Emotional wellbeing and Functional wellbeing. Results: Compared to pegfilgrastim alone, patients on plinabulin + pegfilgrastim performed significantly better for Physical wellbeing on D8 and D15 of Cycle 2 (p < 0.0589 and p < 0.0039 respectively) and Cycle 3 (p < 0.0360 and p < 0.0343 respectively). Further analysis of the sub questions showed that both energy levels “I have a lack of energy” and pain”(I have pain” were significantly better for the plinabulin + pegfilgrastim combination versus pegfilgrastim alone (p < 0.0377 and p < 0.0420 respectively). Overall FACT-G completion compliance for the trial was 91%. Conclusions: The Physical wellbeing (in particular, pain and for energy levels) of patients receiving plinabulin in combination with pegfilgrastim for the prevention of TAC CIN, was significantly less impacted by chemo dosing compared to the pegfilgrastim alone arm. In addition, the results suggest that patients receiving the combination therapy recovered their pre-chemo Physical wellbeing levels more rapidly. Clinical trial information: NCT03531099.

scholarly journals The confrontation between general relativity and experiment

2009 ◽  
Vol 5 (S261) ◽  
pp. 198-199
Author(s):  
Clifford M. Will
Keyword(s):  
General Relativity ◽  
Gravitational Wave ◽  
Equivalence Principle ◽  
Gamma Ray ◽  
Strong Field ◽  
Weak Field ◽  
X Ray ◽  
Spacetime Geometry ◽  
Tests Of General Relativity ◽  
Laser Interferometric

AbstractWe review the experimental evidence for Einstein's general relativity. A variety of high precision null experiments confirm the Einstein Equivalence Principle, which underlies the concept that gravitation is synonymous with spacetime geometry, and must be described by a metric theory. Solar system experiments that test the weak-field, post-Newtonian limit of metric theories strongly favor general relativity. Binary pulsars test gravitational-wave damping and aspects of strong-field general relativity. During the coming decades, tests of general relativity in new regimes may be possible. Laser interferometric gravitational-wave observatories on Earth and in space may provide new tests via precise measurements of the properties of gravitational waves. Future efforts using X-ray, infrared, gamma-ray and gravitational-wave astronomy may one day test general relativity in the strong-field regime near black holes and neutron stars.

scholarly journals Ligand-Field Spin-Orbit Energy Levels in the d5 Electron Configuration of Octahedral and Tetrahedral Symmetry

1974 ◽  
Vol 29 (3) ◽  
pp. 419-428 ◽  
Author(s):  
E. König ◽  
R. Schnakig ◽  
S. Kremer
Keyword(s):  
Strong Field ◽  
Energy Levels ◽  
Orbit Interaction ◽  
Complete Agreement ◽  
Ligand Field ◽  
Electron Configuration ◽  
Spin Orbit ◽  
Tetrahedral Symmetry ◽  
Spin Orbit Interaction ◽  
Orbit Perturbation

The complete ligand-field, Coulomb interelectronic repulsion, and spin-orbit interaction matrices have been derived for the d5 electron configuration within octahedral (Oh) and tetrahedral (Td) symmetry. The calculations were performed in both the weak-field and strong-field coupling schemes and complete agreement of the results was achieved. The energy matrices are parametrically dependent on ligand field (Dq), Coulomb repulsion (B, C), and spin-orbit interaction (ζ). Correct energy diagrams are presented which display the splittings by spin-orbit perturbation as well as the effect of configuration mixing. Applications to the interpretation of electronic spectra, and to complete studies in magnetism are pointed out. The detailed behavior at the crossover of ground terms is considered

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