Pairing Energy Research Articles

Segmentation Algorithm of Medical Exercise Rehabilitation Image Based on HFCNN and IoT

Deep learning has achieved great success in the field of computer vision, and the precision in image classification and image detection has surpassed humans. Therefore, this paper combines deep learning and medical image segmentation, focusing on how to improve the accuracy and speed of segmentation algorithm of medical exercise rehabilitation image. Aiming at the shortcomings of traditional medical image recognition methods, a medical exercise rehabilitation image segmentation algorithm based on hierarchical features of convolutional neural networks is proposed, this paper calls it as hierarchical features of convolutional neural networks (HFCNN). The algorithm firstly samples the convolution output of multiple layers in the convolutional neural network to a unified scale and combines them to construct a hierarchical feature. This hierarchical feature combines the structural information of objects contained in the shallow layer of the network with the semantic information of objects contained in the deep layers of the network, so it has a strong ability to express. Secondly, the image can be segmented into multiple super pixels by the super pixel segmentation algorithm. The classifier is trained using the hierarchical features of the super pixel, and then the classification result is mapped back to the pixel. Finally, a fully connected conditional random field algorithm including one-potential potential energy and paired potential energy is constructed. The corresponding energy function is used to smooth the classification result of the pixel, and the regional consistency and continuity of the pixel mark are improved. Compared with many classical convolutional neural network algorithms, this algorithm not only accelerates the network convergence speed, shortens the training time, but also significantly improves the accuracy of segmentation algorithm of medical exercise rehabilitation image, showing good practical value.

A Two-Stage Energy-Efficient Approach for Joint Power Control and Channel Allocation in D2D Communication

A large number of mobile multimedia terminals are prominent features of smart cities. Device-to-device (D2D) communication takes advantage of the limited bandwidth resources of cellular networks to accommodate more mobile devices. However, when D2D pairs reuse cellular users channels, serious interference leads to energy consumption, which dissatisfies the requirements of green communication. This paper focuses on energy efficiency maximization of D2D communication under the constraints of both D2D pairs and cellular users quality of service. The formulated resource allocation problem is NP-hard, which is usually difficult to solve within polynomial time. To make the problem easy to handle, we divide it into power control and channel allocation sub-problems. In particular, we propose a power control algorithm based on the Lambert W function to maximize the energy efficiency of a single D2D pair. The preference values of D2D pairs and cellular users are calculated using the power control results, respectively. A channel allocation scheme based on the Gale-Shapley algorithm utilizes preference values to match two sides, which aims at maximizing the signal to interference plus noise ratio of cellular users and the energy efficiency of D2D pairs. The simulation results show that the proposed algorithm could not only guarantee the transmission rate of cellular users but also improve the system and D2D pairs energy efficiency.

ChemGenome2.1: An Ab Initio Gene Prediction Software.

Gene prediction, also known as gene identification, gene finding, gene recognition, or gene discovery, is among one of the important problems of molecular biology and is receiving increasing attention due to the advent of large-scale genome sequencing projects. We designed an ab initio model (called ChemGenome) for gene prediction in prokaryotic genomes based on physicochemical characteristics of codons. In this chapter, we present the methodology of the latest version of this model ChemGenome2.1 (CG2.1). The first module of the protocol builds a three-dimensional vector from three calculated quantities for each codon-the double-helical trinucleotide base pairing energy, the base pair stacking energy, and an index of the propensity of a codon for protein-nucleic acid interactions. As this three-dimensional vector moves along any genome, the net orientation of the resultant vector should differ significantly for gene and non-genic regions to make a distinction feasible. The predicted putative protein-coding genes from above parameters are passed through a second module of the protocol which reduces the number of false positives by utilizing a filter based on stereochemical properties of protein sequences. The chemical properties of amino acid side chains taken into consideration are the presence of sp3 hybridized γ carbon atom, hydrogen bond donor ability, short/absence of δ carbon and linearity of the side chains/non-occurrence of bi-dentate forks with terminal hydrogen atoms in the side chain. The final prediction of the potential protein-coding genes is based on the frequency of occurrence of amino acids in the predicted protein sequences and their deviation from the frequency values of Swissprot protein sequences, both at monomer and tripeptide levels. The final screening is based on Z-score. Though CG2.1 is a gene finding tool for prokaryotes, considering the underlying similarity in the chemical and physical properties of DNA among prokaryotes and eukaryotes, we attempted to evaluate its applicability for gene finding in the lower eukaryotes. The results give a hope that the concept of gene finding based on physicochemical model of codons is a viable idea for eukaryotes as well, though, undoubtedly, improvements are needed.

Correlation energies for many-electron atoms with explicitly correlated Slater functions

In this work we propose a composite method for accurate calculation of the energies of many-electron atoms. The dominant contribution to the energy (pair energies) are calculated by using explicitly correlated factorizable coupled cluster theory. Instead of the usual Gaussian-type geminals for the expansion of the pair functions, we employ a two-electron Hylleraas basis set and discuss the advantages of the latter approach, e.g., a small number of nonlinear parameters that need to be optimized. The remaining contributions to the energy are calculated within the algebraic approximation by using large one-electron basis sets composed of Slater-type orbitals. The method is tested for the beryllium atom where an accuracy better than $1\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ is obtained. We discuss in detail possible sources of the error and estimate the uncertainty in each energy component. Finally, we consider possible strategies to improve the accuracy of the method by 1--2 orders of magnitude and apply it to larger atoms.

Nodeless High-T_{c} Superconductivity in the Highly Overdoped CuO_{2} Monolayer.

We study the electronic structure and superconductivity in a CuO_{2} monolayer grown recently on the d-wave cuprate superconductor Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}. Density functional theory calculations indicate a significant charge transfer across the interface such that the CuO_{2} monolayer is heavily overdoped into the hole-rich regime yet inaccessible in bulk cuprates. We show that both the Cu d_{x^{2}-y^{2}} and d_{3z^{2}-r^{2}} orbitals become important and the Fermi surface contains one electron and one hole pocket associated with the two orbitals, respectively. Constructing a minimal correlated two-orbital model for the e_{g} complex, we show that the spin-orbital exchange interactions produce a nodeless superconductor with extended s-wave pairing symmetry and a pairing energy gap comparable to the bulk d-wave gap, in agreement with recent experiments. The findings point to a direction of realizing new high-T_{c} superconductors in ozone grown transition-metal-oxide monolayer heterostructures.

Empirical pairing gaps and neutron-proton correlations**The work of S. Sidorov was Supported by Foundation for the Advancement of Theoretical Physics and Mathematics BASIS

Analysis of various mass formulas related to neutron-proton correlations in atomic nuclei is carried out. Using the example of the N = Z chain it is shown that for self-adjoint nuclei various formulas proposed in literature for estimating the np pairing energy lead to similar results. Significant differences between the calculation methods arise when nuclei with N ≠ Z are considered, which allows to reveal the complexity of neutron-proton correlations in different types of atomic nuclei and to make assumptions on the correspondence of the mass relation to the real effect of np pairing. The Shell Model parametrization of the binding energy makes it possible to draw additional conclusions on the structure of mass formulas and their relationship.

A universal COMB potential for the whole composition range of the uranium[sbnd]oxygen system

An empirical molecular dynamics potential in the Charge-Optimized Many-Body (COMB) formalism that covers the whole uranium-oxygen composition range has been developed. Extended from a previous potential for uranium metal, this universal UO potential is able to model more than 20 phases of uranium oxides. The potential's flexibility, accuracy and transferability have been fully verified by rigorous testing and comparison with ab-initio calculations and experimental measurements. It is shown to be one of the most versatile and high-quality UO2 potentials, the first potential for U4O9, U3O7 and UO3, and the first usable U3O8 potential. Many important properties of major oxides in the UO phase diagram have been calculated and critically reviewed, including the cohesive energy, formation/reaction energies, lattice parameters, elastic constants, bulk/shear moduli, and energies for non-stoichiometric point defects and stoichiometric defects pairs. Due to its special design and parameterization process, this UO potential is shown to outperform all other existing ones by either obtaining higher accuracy for many of these quantities, or exclusively being able to calculate some of them. The successfully development of this potential provides a useful, reliable and convenient tool for molecular dynamics simulations that are previously impossible or unreliable to do for many materials in the UO system. Correction for several published oxide structures is also included in the appendix.

Thermodynamically Motivated Criterion of Hydrogen Bonds in Water Simulations

A computer simulation study of a system containing 33666 SPC/E water molecules at the atmospheric pressure and room temperature is carried out. A thermodynamically motivated geometric criterion of the hydrogen bond is developed based on statistical regularities of joint distributions of oxygen-oxygen, oxygen-hydrogen distances, and the interaction energies of molecular pairs corresponding to these distances. Using this criterion makes it possible to substantially increase the selectivity of the algorithms for identifying hydrogen bonds during computer simulation.

On classical and non-classical views on nucleation

Classical nucleation theory (CNT) is based on the notion of critical nuclei serving as transition states between supersaturated solutions and growing particles. Their excess standard free energy depends on supersaturation, and determines the height of the barrier for phase separation. However, predictions of CNT nucleation rates can deviate from experimental observations by many orders of magnitude. We argue that this is due to oversimplifications within CNT, rendering the critical nucleus essentially a conceptual notion, rather than a truly existing physical entity. Still, given adequate parametrization, CNT is useful for predicting and explaining nucleation phenomena, since it is currently the only quantitative framework at hand. In the recent years, we have been introducing an alternative theory, the so-called pre-nucleation cluster (PNC) pathway. The truly “non-classical” aspect of the PNC pathway is the realization that critical nuclei, as defined within CNT, are not the key to nucleation, but that the transition state relevant for phase separation is based on a change in dynamics of PNCs rather than their size. We provide a summary of CNT and the PNC pathway, thereby highlighting this major difference. The discussion of recent works claiming to provide scientific evidence against the existence of PNCs reveals that such claims are indeed void. Moreover, we illustrate that an erroneous interpretation of the concentration dependence of the free energy has led to a postulated rationalization of the standard free energy of ion pairs and stable ion associates within CNT, which is not sustainable. In fact, stable ion associates are stuck in a free energy trap from the viewpoint of CNT and cannot be considered in a straightforward manner. On the other hand, the notions of the PNC pathway, by dismissing the idea of the CNT-type critical nucleus as a required transition state, overcome this issue. While a quantitative theory of the PNC pathway is eagerly anticipated, the rationalization of experimental observations that are inconsistent with CNT proves its qualitative explanatory power, underpinning great promise towards a better understanding of, for instance, polymorph selection and crystallization control by additives.

On the improvement of visible-responsive photodegradation through artificial cilia

Photocatalysts as a semiconductor material are widely used in the field of water and environment cleaning applications as it equips with favorite features such as chemical and physical stability, easy availability, inexpensive, and non-toxic in nature. Additionally, photocatalysts can convert the light energy of the irradiation into the chemical energy of the electron-hole pairs. Most commonly used TiO2 can function as the efficient photocatalysts in the presence of light. However it is a material which majorly requires UV light for its activation, and it is not practically being useful. In this aspect, the proposed study demonstrated that with a combination of SnFe2O4 nanoparticles with magnetic artificial cilia, a highly efficient catalytic activity can be achieved under the visible light due to the rapid and uniform mixing within the microfluidic device with least energy budget. To identify the optimal advanced oxidation process using the selected photocatalyst running with the microfluidics, a micro-particle image velocimetry analysis was carried out through three modes of artificial cilia rotation. The study also determined the evolution curves of the degradation rate with respect to time for all of three modes of cilia rotation, and a superior performance was achieved with a maximum degradation rate of 81.7% in 60 min using the presented design concept.

Low-energy phase boundary pairs and preferred crystallographic orientations of olivines in nanometer-sized ultrapotassic fluid inclusions of Aykhal diamond

The healed internal conjugated cleavages at the core of Aykhal octahedral diamond sample AH2 were decorated with {111}dia-facetted ultrapotassic fluid/melt inclusion pockets containing nanosized graphite, phlogopite and olivine (Fo92) inclusions. These olivines are either rounded in pockets with ample fluid, or facetted by the {111}dia mold in the pockets with a fluid film. Transmission electron microscopy revealed two distinct crystallographic characteristics of olivine inclusions: (1) pronounced crystallographic texture of olivines grouped in specific diamond domain, and (2) frequent parallelism or sub-parallelism of specific low-energy faces of the two phases, mainly (010)ol, {120}ol, (001)ol and {111}dia, {110}dia, {100}dia in the order of decreasing preference, forming prominent (010)ol/{111}dia, (010)ol/{110}dia, (001)ol/{110}dia, {120}ol/{111}dia, and {120}ol/{110}dia low-energy phase boundaries with thin liquid film of 1–2 nm in between. These findings not only testify to the extremely low adhesion energies of olivine-diamond boundary pairs, but also imply that, in the presence of a fluid phase, the interfacial energetics and the energetically favored crystallographic orientations of olivine inclusions in diamond can be controlled simply by the settlement/attachment of low-energy facets of olivine crystals precipitating from the parental fluid upon the low-energy {111}dia or {110}dia surfaces of diamond. Such interfacial energetics control and the resultant low-energy boundary pairs are characteristically distinct from the common topotaxy or epitaxy between oxide/silicate mineral pairs, but are in a sense like the Van der Waals heteroepitaxy in artificial systems.

Role of shell and pairing correction in the dynamics of compound nuclei with ACN = 118–196 using collective clusterization approach

Shell and pairing correction are known to significantly affect the binding energy of a nucleus. In the present work, the effect of shell correction and pairing energy on the fusion-evaporation cross sections (σER) and the reaction dynamics of five different hot and rotating compound systems 118Xe⁎, 128Ce⁎, 146Sm⁎, 172Yb⁎, and 196Pt⁎ formed via respective entrance channels namely Si28+Zr90 (ηi=0.525), S32+Mo96 (ηi=0.5), 36S + 110Pd (ηi=0.506), 124Sn + 48Ca (ηi=0.442) and 132Sn + 64Ni (ηi=0.346) (ηi represents the entrance channel mass asymmetry) is studied within the collective clusterization approach. The basis of choosing these reactions is to keep entrance channel mass asymmetry in such a way that the temperature (T) of the compound systems lie in the common range of 1.6 MeV to 1.9 MeV corresponding to the available experimental data. It is observed that the magnitude of fragmentation potential and preformation probability of decaying fragments is influenced with the inclusion of shell correction and pairing energy, while the overall decay pattern remains unaffected except that, few fragments minimized in energy correspond to different atomic (Z)-number compared to the case when the shell and pairing correction is not taken into account. The change of magnitude ultimately modifies the fusion-evaporation cross sections of the compound systems. The effect is more pronounced at the lower temperature or below barrier incident energies. The pairing energy has a relatively lesser influence on the considered observables as compared to the shell correction term. The order of sequence in which the shell and pairing energy is switched off leaves the decay structure unaltered, however the fusion-evaporation cross sections are influenced significantly if the charge of evaporation residue (ER) gets changed.

Application of stable isotope dimethyl labeling for MRM based absolute antigen quantification of influenza vaccine

Determining the precursor/product ion pair and optimal collision energy are the critical steps for developing a multiple reaction monitoring (MRM) assay using triple quadruple mass spectrometer for protein quantitation. In this study, a platform consisting of stable isotope dimethyl labeling coupled with triple-quadruple mass spectrometer was used to quantify the protein components of the influenza vaccines. Dimethyl labeling of both the peptide N-termini and the ϵ-amino group of lysine residues was achieved by reductive amination using formaldehyde and sodium cyanoborohydrate. Dimethylated peptides are known to exhibit dominant a1 ions under gas phase fragmentation in a mass spectrometer. These a1 ions can be predicted from the peptide N-terminal amino acids, and their signals do not vary significantly across a wide range of collision energies, which facilitates the determination of MRM transition settings for multiple protein targets. The intrinsic a1 ions provide sensitivity for acquiring MRM peaks that is superior to that of the typical b/y ions used for native peptides, and they also provided good linearity (R2 ≥ 0.99) at the detected concentration range for each peptide. These features allow for the simultaneous quantification of hemagglutinin and neuraminidase in vaccines derived from either embryo eggs or cell cultivation. Moreover, the low abundant ovalbumin residue originated from the manufacturing process can also be determined. The results demonstrate that the stable isotope dimethyl labeling coupled with MRM Mass spectrometry screening of a1 ions (i.e., SIDa-MS) can be used as a high-throughput platform for multiple protein quantification of vaccine products.

Superconducting Phases in Lithium Decorated Graphene LiC6

A study of possible superconducting phases of graphene has been constructed in detail. A realistic tight binding model, fit to ab initio calculations, accounts for the Li-decoration of graphene with broken lattice symmetry, and includes s and d symmetry Bloch character that influences the gap symmetries that can arise. The resulting seven hybridized Li-C orbitals that support nine possible bond pairing amplitudes. The gap equation is solved for all possible gap symmetries. One band is weakly dispersive near the Fermi energy along Γ → M where its Bloch wave function has linear combination of {d}_{{x}^{2}-{y}^{2}} and dxy character, and is responsible for {d}_{{x}^{2}-{y}^{2}} and dxy pairing with lowest pairing energy in our model. These symmetries almost preserve properties from a two band model of pristine graphene. Another part of this band, along K → Γ, is nearly degenerate with upper s band that favors extended s wave pairing which is not found in two band model. Upon electron doping to a critical chemical potential μ1 = 0.22 eV the pairing potential decreases, then increases until a second critical value μ2 = 1.3 eV at which a phase transition to a distorted s-wave occurs. The distortion of d- or s-wave phases are a consequence of decoration which is not appear in two band pristine model. In the pristine graphene these phases convert to usual d-wave or extended s-wave pairing.

A theoretical and experimental study on the effect of cationic moiety of quaternary ammonium tribromides in bromination reactions

Attempt has been made to explain why different aliphatic quaternary ammonium tribromides (QATBs) show different levels of efficiency in bromination reactions. For this study, tetrabutyl ammonium tribromide (TBATB, [N(C4H9)4]Br3), and cetyl trimethyl ammonium tribromide (CTMATB, [N(CH3)3C16H33]Br3) were used as representative examples. UV–Vis Spectroscopic method was employed to measure the thermodynamic parameters of the reactions. Influence of quaternary ammonium cation on tribromide (Br3−) performance was assessed with the aid of Density Functional Theory (B3LYP/6-311++G(d,p)) by determining the dissociation energy of the QATBs, energies of pairs of their frontier orbitals, which are HOMO and LUMO and calculation of dipole moments.

Potential discovery of staus through heavy Higgs boson decays at the LHC

In this work we present a new search strategy for the discovery of staus at the LHC in the context of the minimal supersymmetric standard model. The search profits from the large s-channel b-quark annihilation production of the heavy CP-even and CP-odd Higgs bosons (H/A) which can be attained in regions of tan β ≫ 1 that avoid the stringent H/A → τ+τ− searches via decays into stau pairs. We also focus on regions where the staus branching ratios are dominated by the decays into a tau lepton and the lightest neutralino. Thus the experimental signature consists of final states made up of a tau-lepton pair plus large missing transverse energy. We take advantage of the large stau-pair production cross sections via heavy Higgs boson decays, which are between one or two orders of magnitude larger than the usual electroweak production cross sections for staus. A set of basic cuts allow us to obtain significances of the signal over the SM backgrounds at the discovery level (5 standard deviations) in the next LHC run with a center-of-mass energy of 14 TeV and a total integrated luminosity of only 100 fb−1.

Site preferences of alloying transition metal elements in Ni-based superalloy: A first-principles study**Project supported by the National Key R&D Program of China (Grant Nos. 2017YFB0701501, 2017YFB0701502, and 2017YFB0701503).

Atomistic characterization of chemical element distribution is crucial to understanding the role of alloying elements for strengthening mechanism of superalloy. In the present work, the site preferences of two alloying elements X–Y in γ-Ni of Ni-based superalloy are systematically studied using first-principles calculations with and without spin-polarization. The doping elements X and Y are chosen from the 27 kinds of 3d, 4d, 5d group transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au) and Al. We find that the spin-polarized calculations for Re–Re, Re–Ru, Re–Cr, Ru–Cr show a strong chemical binding affinity between the solute elements and are more consistent with the experimental results. The binding energies of pairs between the 28 elements have an obvious periodicity and are closely related the electronic configuration of the elements. When the d-electrons of the element are close to the half full-shell state, two alloying elements possess attractive binding energies, reflecting the effect of the Hund’s rule. The combinations of early transition metals (Sc, Ti, V, Y, Zr, Nb, Hf, Ta) have a repulsive interaction in γ-Ni. These results offer insights into the role of alloying elements for strengthening mechanism of superalloy.

Proton Transfer in 1,2,4-Triazolium Dinitramide: Effect of Aqueous Microsolvation.

The gas phase proton transfer process in 1,2,4-triazolium dinitramide (TD) was studied using second-order perturbation theory to determine how the presence of one and two water molecules modifies the potential energy surface that connects the ion pair to the neutral pair. The presence of one water molecule can introduce small proton transfer energy barriers that separate the ion pair from the lower-energy neutral pair. These energy barriers are easily surmounted. Reaction paths were determined for single proton transfers and double proton transfers via one water molecule. In the presence of two water molecules, the global minimum is an ion pair, as are most of the lower-energy local minima. Energy barriers for single, double, and triple proton transfers were also found for TD in the presence of two water molecules. One TD ion pair structure with two water molecules has no corresponding neutral pair energy minimum. A quasi-atomic orbital analysis is used to understand the nature of the bonding in the various species studied in this work.

Time-dependent pair density from the principle of minimum Fisher information.

The Euler equation for the time-dependent pair density is derived from the principle of minimum Fisher information. The same Euler equation is also derived from the recently introduced time-dependent pair density functional theory. The concept of steric effect to electron pairs is proposed and the steric pair energy is defined as the Weizsäcker kinetic energy of electron pairs.

Corrections to the Casimir–Polder potential arising from electric octupole coupling

ABSTRACTMolecular QED theory is employed to derive a generalised formula for the dispersion potential between two molecules with mixed electric multipole polarisability tensors of arbitrary order at each centre. This expression is used to readily extract the pair energy shift between an electric dipole polarisable molecule and a mixed electric dipole–octupole polarisable one, and that between two mixed electric dipole–octupole polarisable species. This is done to see whether these interaction energies give rise to higher-order corrections to the Casimir–Polder potential, as was found in the previously calculated case of the dispersion energy shift between an electric dipole polarisable molecule and an electric octupole polarisable one. Interestingly, for orientationally averaged species, both of the computed interaction energies are independent of the octupole weight-3 term, are retarded, and may be interpreted as higher-order corrections in the fine structure constant to the leading dipole–dipole dispersion potential.