Kinds Of Pairs Research Articles

Investment Trade-Off between Mating Behavior and Tonic Immobility in the Sweetpotato Weevil Cylas formicarius (Coleoptera: Brentidae).

Numerous studies have confirmed that the trade-off between anti-predator behavior and mating behavior occurs in certain insect species. This suggests that insects invest more in anti-predator behavior, and fewer resources or time can be used in mating behavior. However, few studies focus on tonic immobility, an important anti-predator behavior in nature, and different stages in mating behavior. Tonic immobility (TI) is considered to be an important anti-predator behavior. Herein, we investigated the relationship between TI and mating behavior in the sweetpotato weevil (SPW), Cylas formicarius. As the first step, we artificially selected SPWs for the longer duration of TI (L-strain) and the shorter duration of TI (S-strain). The effect of courtship and copulation on the duration of TI in two artificial selection strains was tested. Furthermore, we compared the frequency and duration of two mating behaviors in four kinds of pairs (LF×LM, LF×SM, SF×LM, and SF×SM: LM-L-strain male; SM-S-strain male; LF-L-strain female; SF-S-strain female). Finally, we tested insemination success in four kinds of pairs (male and female SPWs from the L-strain or the S-strain). The courtship and copulation significantly reduced the duration of TI. Pairs with males from the L-strain showed lower frequency and longer duration of courtship than pairs with males from the S-strain. Similarly, males from L-strain pairs showed a longer period of copulation than pairs with males from the S-strain. However, there is no significant difference in the frequency of copulation and the success of insemination. These results support that there was a significant trade-off between TI and courtship as well as copulation in the SPW.

Fractionalized Kitaev model in a low magnetic field along [1 1 1

Kitaev model in the presence of the magnetic field along the [111]-direction hosts topological excitations; the field dependence of the Kitaev model is specifically revisited in terms of fractionalized excitations. The weak-field limit is examined in terms of fractionalized spinon excitations employing Hartree-Fock BdG mean-field theory on a fermionized Kitaev model. We show that the original model of spins on a honeycomb lattice can be mapped on to a model of BCS superconductor constituting different kinds of pairing with a local constraint embodied in the model. It is also shown that the ground state Kitaev model has pairing on certain bonds forming a topological quantum order such as dimer model of valence bond solid in the low-field side. This order vanishes with the increasing magnetic field and at a critical field pairing vanishes, hence driving the system to a gapped phase.

Thermodynamic properties in the extended BCS-Bose crossover theory

Superconductivity in a generalized Bose-Einstein condensation theory is addressed. This theory contains three coupled transcendental equations for all temperatures: two gap-like equations and a particle number density equation that guarantees charge conservation. Here we explore the special case of an extended BCS-Bose crossover picture as two-hole Cooper pairs are explicitly included. Using the dimensionless coupling parameter n/nf where n is the total electron number density and nf that of unpaired electrons at zero absolute temperature, we solved the three associated coupled equations yielding two pure Bose-Einstein-condensation phases of two-electron Cooper pairs and/or of two-hole Cooper pairs plus a mixed phase with varying proportions of both kinds of pairs. We find that the mere inclusion of two-hole Cooper pairs can lead to critical temperatures enhanced by several orders of magnitude compared with BCS theory. We also found a weak-intermediate and strong-coupling regimes. Afterwards, we calculated the entropy within the BCS-Bose crossover theory and from the numerical derivative of the entropy we analysed the rest of the well-known thermodynamic quantities that can be compared with experimental data. Results fit better for elemental superconductors, suggesting that two-hole Cooper pairs might be indispensable to describe this kind of materials.

Error correction by Reed–Solomon codes using its automorphisms

The article explores the syndrome invariants of АГ-group of automorphisms of Reed–Solomon codes (RS-codes) that are a joint group of affine and cyclic permutations. The found real invariants are a set of norms of N Г-orbits that make up one or another АГ-orbit. The norms of Г-orbits are vectors with 2 1 Cδ− coordinates from the Galois field, that are determined by all kinds of pairs of components of the error syndromes. In this form, the invariants of the АГ-orbits were cumbersome and difficult to use. Therefore, their replacement by conditional partial invariants is proposed. These quasi-invariants are called norm-projections. Norm-projection uniquely identifies its АГ-orbit and therefore serves as an adequate way for formulating the error correction method by RS-codes based on АГ-orbits. The power of the АГ-orbits is estimated by the value of N2, equal to the square of the length of the RS-code. The search for error vectors in transmitted messages by a new method is reduced to parsing the АГ‑orbits, but actually their norm-projections, with the subsequent search for these errors within a particular АГ-orbit. Therefore, the proposed method works almost N2 times faster than traditional syndrome methods, operating on the basic of the “syndrome – error” principle, that boils down to parsing the entire set of error vectors until a specific vector is found.

Insight on the Mechanical and Tribological Characteristics of Ball-on-Socket Artificial Disc under Alternate Motion of Flexion Extension–Axial Rotation and Lateral Bending–Axial Rotation

Ball-on-socket articulation is the major structural type of artificial joints. The insight on the mechanical and bio-tribological characteristics of this structure is important for designing both the device itself and its wear assessment regime. Two kinds of ball-on-socket structures were studied including a simplified general model and a real artificial cervical disc. The bio-tribological behaviors were evaluated by in vitro wear simulation method using four kinds of pairs with different combinations of structure, frictional material and testing duration under alternate motion of FE-AR (flexion extension and axial rotation) and LB-AR (lateral bending and axial rotation). In order to analyze the formation mechanism of representative wear characteristics, the mechanical behaviors were also studied by finite element analysis method. The results indicated that there were similar mechanical and bio-tribological characteristics for these two structures after about 9 MC (Million Cycles) tests. Under the axial load, it revealed more serious wear severity in the edge region than that in the central region for both convex polymer component and concave metal component, which may be due to much higher values of equivalent stress and equivalent elastic strain in the edge region than that in the central region. Under FE (flexion extension) or LB (lateral bending) motion, it showed common wide and curved wear grooves with ring distribution in the edge region for both ball component and nucleus pulposus component, which may be attributed to the higher equivalent stress and equivalent elastic strain at the limit position. It just indicated several sliding scratches for TC4 (Ti6Al4V alloy) metal component with an abrasive wear mechanism, while it revealed plastic deformation, surface cracks, sliding scratches and wear grooves for XPE (crosslinking polyethylene) polymer component with a mix of abrasive wear and adhesive wear mechanism. Hence, there was a strong correlation between structural design and bio-tribological characteristics for ball-on-socket prostheses.

Common fixed points via asymptotic contraction and application to matrix equations

In this paper, we employ the notion asymptotic contraction of Kirk (J Math Anal Appl 277:645–650, 2003) to obtain some common fixed point results of a pair of mappings and a finite family of mappings. To execute this, we introduce the notion of asymptotic contractions in pair for a finite family of mappings. Then, we obtain our prescribed common fixed point results using these asymptotic contractions in pair concepts. After this, we apply these results to analyze the unique common solution to a certain kind of pair of matrix equations. Finally, we provide some numerical examples to authenticate our results using figurative presentations.

Superconducting pairing symmetries of the Hubbard model on the honeycomb lattice with inhomogeneous hopping strength

Using finite-temperature determinantal quantum Monte Carlo calculations, we find that the dominant pairing symmetries in the standard Hubbard model on the honeycomb lattice depend on the electron filling. When the electron density $\ensuremath{\rho}$ is larger than around 0.25, the dominant pairing symmetry is the $d+id$-wave; when the electron density is low enough ($\ensuremath{\rho}\ensuremath{\lesssim}0.25$), the dominant pairing symmetry is the $p+ip$ wave. For two electron densities $\ensuremath{\rho}=0.1$ and $\ensuremath{\rho}=0.4$, where the dominant pairing symmetries are $p+ip$ wave and $d+id$ wave separately, we study the effect of two types of hopping inhomogeneities (the plaquette and the quasi-$1\mathrm{D}$ hopping inhomogeneities) on the pairing symmetries. For $\ensuremath{\rho}=0.1$, the plaquette hopping inhomogeneity drives the dominant $p+ip$-wave pairing symmetry into the $d+id$-wave; while the quasi-$1\mathrm{D}$ hopping inhomogeneity almost does not affect the $p+ip$ wave, and arises the $f$ wave, causing the coexistence of $p+ip$-wave and $f$-wave pairing. For $\ensuremath{\rho}=0.4$, both the plaquette and the quasi-$1\mathrm{D}$ hopping inhomogeneities destroy the $d+id$-wave pairing symmetry, without causing other pairing symmetry. Our results suggest that the effect of hopping inhomogeneity on the pairing symmetries is robust and depends on the electron filling. This finding may be useful for the design of artificial graphene superconductors with different kinds of pairing, especially for the realization of the $d+id$-wave, $p+ip$-wave, or $f$-wave superconductors at low filling.

Tunneling spectrum in triplet p-wave superconductor-silicene junctions

The tunneling spectrum in normal/triplet p- wave superconductor (N/p S)-undoped and doped silicene junction is studied based on Blonder-Tinkham-Klapwijk (BTK) theory. Three kinds of pairings for p S are chosen: p x , p y , p x + ip y waves. It is found that the normalized conductance (NC) strongly depends on the kind of pairings, the insulating gap which varies in magnitude with an applied electric field (Ez ) and the chemical potential in the normal silicene region. For N/p S-undoped silicene junctions, the Andreev reflection (AR) and the NC can be switched on or off by the applied electric field while the transport can occur for all the bias voltage in doped silicene junctions. A sharp zero-bias conductance peak (ZBCP) is obtained in N/p S-doped silicene junction that is independent of the values of the insulating gap of silicene and distinctly different from the normal/d- wave superconductor-silicene junctions. In addition, for N/p x S-silicene junctions the NC exhibits a double-minimum structure when the bias voltage eV = 0.8Δ0 with Δ0 the zero-temperature energy gap of p S while a little peak appears for N/p y S case. In N/p x +ip y S-silicene junctions a sharp peak and a conductance dip appear at eV = 0.8Δ0 and eV = Δ0 , respectively. It is hoped that the results obtained may guide the design of silicene devices.

Experimental comparison of CuAl10Fe3 journal bearings sliding against two different coatings

PurposeThe purpose of this paper is to study the frictional behaviors of CuAl10Fe3 journal bearings sliding against chromium electroplated 42CrMo shafts and diamond-like carbon-coated 42CrMo shafts, respectively, under two different conditions and to compare the two kinds of friction pairs.Design/methodology/approachAll journal bearing samples underwent 24 h running-in and repeatability verification. Then, the journal bearing friction experiments were carried out under two different conditions. After testing, the torques, friction coefficients, power consumptions and other parameters were obtained.FindingsThe pair of CuAl10Fe3 journal bearing and diamond-like carbon–coated shaft could drive greater load to start up than the pair of CuAl10Fe3 journal bearing and chromium electroplated 42CrMo shaft, but it had greater power consumption during the steady running period under the identical condition. With the changing of specific pressure or rotational speed, the friction coefficients had different variations. The frictional oscillations appeared at 32 rotations per minute under heavy loads for both kinds of pairs, the oscillation frequencies were equal to rotational frequency of the test shaft and the oscillation amplitude for diamond-like carbon coating was much greater.Originality/valueThese results have guiding significance for practical industrial applications.

On the Cooperativity Effect in Watson and Crick and Wobble Pairs for a Halouracil Series and Its Potential Quantitative Application Studied through Surface-Enhanced Raman Spectroscopy.

The nature of the cooperativity effect of hydrogen bonds in Watson and Crick and wobble base pairs formed with thymine, uracil, and its 5-halogenated derivatives (5-fluoro, -chloro, and -bromouracil) has been studied through SERS and by using chemometric tools to process data and extract relevant information. Remarkable differences between the two kinds of pairs were clearly observed, and the behavior correlated to the withdrawing character of different substituents at the 5-position of uracil was verified. Multivariate analyses have also unveiled information about the pair's stability, and a stronger cooperativity effect seems to rule the Watson and Crick pairs when compared to wobble pairs. Defined patterns in the behavior of Watson and Crick pairs allowed the design of an indirect methodology for quantifying 5-bromouracil using a partial least squares (PLS) method with variable selection. Limit of detection (LOD) values of 0.037 and 0.112 mmol L-1 in the absence and presence of structurally similar interferences were reached, while its direct surface-enhanced Raman spectroscopy (SERS) quantification is only possible at ∼45 mmol L-1.

On Instantiating Pairing-Based Protocols with Elliptic Curves of Embedding Degree One

Since the discovery of identity-based encryption schemes in 2000, bilinear pairings have been used in the design of hundreds of cryptographic protocols. The most commonly used pairings are constructed from elliptic curves over finite fields with small embedding degree. These pairings can have different security, performance, and functionality characteristics, and were therefore classified into Types 1, 2, 3 and 4. In this paper, we observe that this conventional classification is not applicable to pairings from elliptic curves with embedding degree one. It is important to understand the security, efficiency, and functionality of these pairings in light of recent attacks on certain pairings constructed from elliptic curves with embedding degree greater than one. We define three kinds of pairings from elliptic curves with embedding degree one, discuss some subtleties with using them to implement pairing-based protocols, and provide an estimated cost of implementing them on modern processors.

The Biotribological Behaviour of an Artificial Cervical Disc Model with Ball-on-Socket Contact Type Under Different Material Configurations

The artificial cervical disc was simplified and designed as a ball-on-socket model with the material configuration of polymer-on-Ti6Al4V (TC4). The material of polymer ball included ultra-high molecular weight polyethylene and poly(ether ether ketone) (PEEK). In order to improve the wear resistance of TC4, a W-DLC composite coating was also prepared on TC4 socket by physical vapour deposition method. Hence, there were three kinds of pairs including PE/TC4, PE/W-DLC and PEEK/W-DLC. The long-term wear behaviours of these three material configurations were assessed in vitro using a wear simulator under 10 million cycles (MC) testing intervals. The articulating surfaces of ball and socket were characterized by light microscopy and scanning electron microscopy, respectively. The results indicated that polymer component suffered severe damage characterized by scratches, fatigue cracks and arc-shaped wear grooves on the edge zone of ball. Metal component only revealed thin scratches. Compared with polymer component, the wear rate can be omitted for metal component. The dominant wear mechanism was abrasion wear for metal component while the dominant failure mechanism was a mix of ploughing, fatigue and plastic deformation for polymer component. W-DLC coating protected TC4 from being scratched. However, it also brought many coating wear debris and intensified the wear of polymer component. The most wear-resistant material configuration was PE/TC4 with a total wear rate of about 0.81 mg/MC among the three pairs. Titanium was alternative as a bearing surface in cervical implant.

Methodology To Predict PVC Plasticization Using Molecular Simulation by Pairs

This paper presents a methodology to predict PVC plasticization using molecular simulation of binary interaction between molecules in three kinds of pairs: plasticizer-plasticizer, PVC-PVC, and PVC-plasticizer. The plasticization prediction is based on three complementary criteria calculated from thermodynamic data, obtained from molecular simulation. The methodology was applied to a group of commercial products and to potential new plasticizers, specifically glycerol and isosorbide esters. The predictions were contrasted with the experimental performance evaluated with several tests usually employed in PVC industry. The methodology can be used to test molecular structures and to reduce the experimental work necessary for the evaluation of new PVC plasticizers.

Self-Calibration of Catadioptric Camera with Two Planar Mirrors from Silhouettes

If an object is interreflected between two planar mirrors, we may take an image containing both the object and its multiple reflections, i.e., simultaneously imaging multiple views of an object by a single pinhole camera. This paper emphasizes the problem of recovering both the intrinsic and extrinsic parameters of the camera using multiple silhouettes from one single image. View pairs among views in a single image can be divided into two kinds by the relationship between the two views in the pair: reflected by some mirror (real or virtual) and in a circular motion. Epipoles in the first kind of pairs can be easily determined from intersections of common tangent lines of silhouettes. Based on the projective properties of these epipoles, efficient methods are proposed to recover both the imaged circular points and the included angle between two mirrors. Epipoles in the second kind of pairs can be recovered simultaneously with the projection of intersection line between two mirrors by solving a simple 1D optimization problem using the consistency constraint of epipolar tangent lines. Fundamental matrices among views in a single image are all recovered. Using the estimated intrinsic and extrinsic parameters of the camera, a euclidean reconstruction can be obtained. Experiments validate the proposed approach.

Speciation in aqueous solutions of nitric acid

In this study, speciation in aqueous solutions of nitric acid at 25 °C was assessed in two independent ways. First, Raman experiments were carried out and interpreted in terms of free nitrate ions, ion pairs and neutral HNO(3) molecules. In parallel, a model was developed to account for the formation of these two kinds of pairs. It was based on an extension of the binding mean spherical approximation (BiMSA), or associative MSA (AMSA), in which the size and the charge of the ions in the chemical pair may differ from those of the free ions. A simultaneous fit of the osmotic coefficient and of the proportion of free ions (obtained from Raman spectroscopy experiments) led to an estimation of the speciation in nitric acid solutions. The result obtained using this procedure was compared with the estimation obtained from the Raman experiments.

Superconductivity in multiband disordered systems: A vector recursion approach

We present a vector recursion based approach to study the effect of disorder on superconductivity in a system modeled by the two-band attractive Hubbard model. We use the augmented space formalism for the disorder averaging. In the presence of only intraband pairing in a two-band disordered system with disorder in either or both bands, our calculations reveal that the gap survives in the quasiparticle spectrum; similar to single band systems. However, for interband pairing the gap in the quasiparticle spectrum ceases to exist beyond a critical value of the disorder strength. In the presence of both interband and intraband pairing interaction, depending on the relative magnitude of the pairing strength, only a particular kind of pairing is possible for a half filled two-band system.

PAIRING IN NON-FERMI LIQUID IN TERMS OF THE BETHE-SALPETER EQUATION

Pairing between two fermionic excitations in a non-Fermi liquid is considered in terms of the Bethe-Salpeter equation. We consider the pairing in a Fermi system with vanishing spectral weight. It is well known that the quasiparticle pole in the single-particle Green's function in a Non-Fermi liquid is absent or weak. The examples of such systems can be viewed as the "Marginal" Fermi liquid and Luttinger liquid. Another example that has also been considered is the Fermi system with pseudogap behavior in the spectral weight. Although the pairing between two excitations in a non-Fermi liquid is, in general, absent, nevertheless we show that the Cooper's type of pairing can occur and the conditions for such a kind of pairing are discussed. The results have also been applied to the systems with smeared or non-monotonic Fermi distribution. A system that transits from Fermi-type to Bose-type behavior can serve as an example of such systems as discussed.

Generalized BEC in superconductivity

A generalized Bose–Einstein condensation (GBEC) statistical theory of superconductors accounts not for BB interactions but rather for boson–fermion (BF) interactions. It extends the 1989 Friedberg–Lee BEC theory by including as bosons two-hole (2h) singlet Cooper pairs (CPs) in addition to the usual two-electron (2e) ones. It contains BCS theory when both kinds of pairs are equal in the BE condensate and in excited states—at least as far as identically reproducing the BCS gap equation for all temperatures T as well as the T = 0 BCS condensation energy for all couplings. As a ternary BF model with BF interactions, it yields T cs one-to-three orders-of-magnitude higher than BCS theory with the same Cooper/BCS model electron–phonon interaction. These T cs appear to be surprisingly insensitive to the BF interaction.

Theory of the proximity effect at the interface of a normal metal and tripletp-wave superconductor in the clean limit

The superconducting proximity effect in normal metal (N)/triplet $p$-wave superconductor (P) junctions is studied based on the quasiclassical Green's function theory. We present theoretical results for self-consistently determined pair potentials on both the N and P sides as well as the quasiparticle local density of states near the interface. In the present study, for the P side, in order to consider promising pairing symmetries as in ${\mathrm{Sr}}_{2}\mathrm{Ru}{\mathrm{O}}_{4}$, we choose three kinds of pairings: (i) ${p}_{x}$, (ii) ${p}_{y}$, or (iii) ${p}_{x}+i{p}_{y}$ waves. Here, we assume that an attractive interelectron potential on the $N$ side can induce a subdominant $s$-wave pair potential. The spatial dependencies are sensitive to the transparency of the junctions, while the proximity-induced $s$-wave component on the N side does not enhance the magnitude of the pair potential, which breaks the time-reversal symmetry on the P side. The resulting local density of states at the interface has a zero-energy peak, and its splitting depends on the transparency and symmetry of the pair potentials of the junction.

Dual pairs of orthogonal systems of rational matrix-valued functions on the unit circle

SummaryWe analyse certain dual pairs of orthogonal systems of rational matrix-valued functions with poles not located on the unit circle. The rational matrix-valued functions belonging to such kind of pairs are recursively connected similar as the functions of the first and the second kind in the classical theory of orthogonal polynomials on the unit circle. We present some basic facts on these dual pairs and, in particular, we show that the rational matrix-valued functions in question admit specific integral representations.