We present a phenomenological theory of the log-normal statistics commonly observed in filamentary resistive memory and related devices. Based on the central limit theorem that statistics are shown ...to emerge regardless of the underlying material properties when the processes are dominated by thermal activation or tunneling. That takes place in particular for the read-out resistances in the high-resistive (OFF) state, and the random telegraph noise amplitudes, but can be observed in the low-resistive (ON) state as well. We show that the statistics of switching times becomes log-normal when the switching is due to the field induced nucleation.
This paper describes an approach enabling the continuous monitoring of all devices on the Synchrotron Radiation Facility Siberian Circular Photon Source (SRF SKIF) accelerator complex units ...synchronically with the measurements of beam parameters. The operation of devices is monitored in distributed controllers with a frequency of 10 kHz. After detecting any deviations from specified parameters above the tolerance value in the operation of a device, the controller of this device sets a corresponding signal. When a beam exhibits an abnormal behavior, the comparative analysis of synchronous data from the distributed controllers and the beam diagnosing electronics is performed to reveal the device resulting in such a behavior.
Recent expansion of fundamental knowledge on the physiology of lactation, and breast milk exosomes, stem cell biology, mother-child interactions from prenatal period to postnatal development requires ...a progressive, dynamic view from the scientific community and practicing physicians when analyzing known, generally accepted clinical phenomena and patterns (development of the immune system of infants and young children, natural and artificial feeding, features of postnatal development and growth of organs and tissues in children born prematurely). The components of the mother-breast-milk-infant triad are closely related to each other and influence developmental trajectory of the infant. According to modern concepts, breast milk of a nursing woman is a “living, metabolic / endocrine signaling system”, which may be considered an “immune organ” significant for postnatal growth and body programming of a premature baby. A valuable phenomenon of early postnatal development is actively discussed in the special literature, i,e., “microchimerism” caused by breastfeeding which, according to modern concepts, may play a key role in development of immune system and the whole body. Absence of protective (immunomodulatory and regenerative) effects of breast milk from a nursing woman on the spontaneous, uncorrectable impact of adverse factors of prematurity is likely predispose for remodeling and dysfunction of heart in prematurely born children, and, at longer range, in adults. The young children born prematurely show a unique cardiac phenotype characterized by reduced biventricular volume, relatively lower systolic and diastolic function, disproportionate muscle mass gain, clinically manifesting by increased risk of cardiovascular disease, hypertension, and decreased exercise tolerance. Hence, the premature birth may be considered a chronic disease state. Therefore, the natural feeding which provides a natural evolutionarily protective mechanism for the child’s heart should be attributed to the fundamental factors that play a vital role in prevention of cardiovascular diseases in prematurely born children and at later life periods.
Using a low-pressure flow reactor, the kinetic regularities of the reaction of atomic fluorine with monochloroacetic acid at temperature
T
= 293 K are studied. The concentrations of the reagents are ...monitored by molecular beam mass spectrometry, detecting the molecular peaks of the substances. Using the published data, the value of the reaction rate constant
cm
3
molecules
–1
s
–1
, which is the average value determined by comparison with the rate constants of competing reactions (
k
ref
), is calculated. The ratios of the rate constants
k
/
k
ref
, equal to 0.99 ± 0.12 and 0.75 ± 0.04, respectively, are determined for two competing reactions: a fluorine atom with 2-fluoroethanol and a fluorine atom with cyclohexane. The rate constants of the reaction of atomic fluorine with monochloroacetic acid are compared with the rate constants of reactions of atomic fluorine with chlorine-substituted acetic acids: dichloroacetic and trichloroacetic acids.
An increase in the birth rate of premature and low birth weight children at the current level of medical development requires the development of fundamental ideas about the physiology of the ...cardiovascular system in a history of preterm birth from the point of view of pre- and postnatal ontogenesis. For practicing neonatologists, pediatricians, therapists, cardiologists, reproductologists, etc., it is necessary to improve the traditional ideas about the mechanisms of damage to the cardiovascular system in this category of patients. Because it is established that this clinical subgroup is characterized by increased risks of early onset of pathology of the heart and blood vessels, as well as a high mortality rate in adulthood. Pathological changes of the cardiovascular system in conditions of prematurity can occur at various levels of integration of the body (molecular, subcellular, cellular, organ, functional systems, organismal). The use of modern noninvasive technology of “spot tracing” makes it possible to study the features of segmental deformation and the variety of forms of left ventricle (LV) torsion mechanics during postnatal growth and development in prematurely born children. Optimization of research and diagnostic processes in the field of mechanics of the infant heart in the prenatal and postnatal periods from the point of view of progressive data on anatomy, histology, and clinical biochemistry allows us to study the nature of various contractile–rotational models, as well as reasonably assume the contribution of the fibrous skeleton of the infant heart to the formation of “childhood types” of left ventricular twisting. The search and development of informative criteria for the early diagnosis of latent subclinical heart dysfunction in childhood, taking into account the possibilities of non-invasive ultrasound technology of spot tracing (analysis of types of rotational movement, determination of areas of reduced longitudinal deformation of the LV), based on the current provisions of evidence-based medicine, have become quite possible in modern conditions and are demonstrated by the authors in this review. The information offered to the readers will allow them to expand the understanding of the physiology and pathophysiology of the infant heart with a history of premature birth, bearing in mind the fact that prematurity is considered a chronic condition.
The kinetics of the reaction between fluorine atoms and pentafluoropropionic acid has been studied experimentally at T = 262–343 K. The overall reaction rate constant decreases with temperature: k ...1(T) = 6.1 × 10–13 exp(+1166 K)/T) cm3 molecule–1 s–1. The potential energy surface of the reaction has been studied using quantum chemistry. The results were used in transition state theory calculations of the temperature dependences of the rate constants of the two channels of the reaction. The abstraction channel ultimately producing HF, C2F5, and CO2 is dominant at the experimental temperatures; the addition–elimination channel producing C2F5 and CF(O)OH becomes important above 1000 K.
An expression for the binding energies of electrons in the ground state of an atom is derived on the basis of the Bohr–Sommerfeld quantization rule within the Thomas–Fermi model. The validity of this ...relation for all elements from neon to uranium is tested within a more perfect quantum-mechanical model with and without the inclusion of relativistic effects, as well as with experimental binding energies. As a result, the ordering of electronic levels in filled atomic shells is established, manifested in an approximate atomic-number similarity. It is proposed to use this scaling property to analytically estimate the binding energies of electrons in an arbitrary atom.
VEPP-5 Injection Complex Emanov, F. A.; Astrelina, K. V.; Balakin, V. V. ...
Physics of particles and nuclei letters,
08/2023, Letnik:
20, Številka:
4
Journal Article
Recenzirano
—
The VEPP-5 injection complex is a source of intense electron and positron beams that supplies the VEPP-4M and VEPP-2000 accelerator complexes through the K-500 transport channel. At present, the ...injection complex is in regular operation. Work is being carried out to improve the performance and stability of the facility, and possible ways of working with perspective beam users are being considered. This article presents a description of the injection complex and the experience of its operation, as well as the latest improvements being considered.
Experiments on the synthesis of isotopes of element 114 in the
242
Pu +
48
Ca reaction were carried out at a new gas-filled separator DGFRS-2 online to the DC-280 cyclotron of the Superheavy Element ...Factory at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research. The decay properties of
286
Fl and
287
Fl, as well as their α-decay products, were refined. The possibility of the existence of isomeric states in successive α-decays of
287
Fl is discussed. The maximum cross section of
pb was measured for the
242
Pu(
48
Ca, 3
n
)
287
Fl reaction.
