Two-dimensional Parameter Relationships for W UMa-type Systems Revisited

Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems.In this investigation,two-dimensional(2D)relationships for P–MV(system),P–L1,2,M1,2–L1,2,and q–Lratiowere revisited.The sample used is related to 118 contact binary systems with an orbital period shorter than 0.6 days whose absolute parameters were estimated based on the Gaia Data Release 3 parallax.We reviewed previous studies on 2D relationships and updated six parameter relationships.Therefore,Markov chain Monte Carlo and Machine Learning methods were used,and the outcomes were compared.We selected 22 contact binary systems from eight previous studies for comparison,which had light curve solutions using spectroscopic data.The results show that the systems are in good agreement with the results of this study.

Formation of a Rapidly Rotating Classical Be-star in a Massive Close Binary System

This paper investigates the spin-up of a mass-accreting star in a close binary system passing through the first stage of mass exchange in the Hertzsprung gap. Inside an accreting star, angular momentum is carried by meridional circulation and shear turbulence. The circulation carries part of the angular momentum of the accreted layers to the accretor's surface. The greater the rate of arrival of angular momentum in the accretor is, the greater this part. It is assumed that this part of the angular momentum can be removed by the disk further from the accretor. If the angular momentum in the matter entering the accretor is more than half the Keplerian value, then the angular momentum obtained by the accretor during mass exchange stage does not depend on the rate of arrival of angular momentum. The accretor may have the characteristics of a Be-star immediately after the end of mass exchange.

Type Ia Supernova Explosions in Binary Systems:A Review

Type Ia supernovae(SNe Ia)play a key role in the fields of astrophysics and cosmology.It is widely accepted that SNe Ia arise from thermonuclear explosions of white dwarfs(WDs)in binary systems.However,there is no consensus on the fundamental aspects of the nature of SN Ia progenitors and their actual explosion mechanism.This fundamentally flaws our understanding of these important astrophysical objects.In this review,we outline the diversity of SNe Ia and the proposed progenitor models and explosion mechanisms.We discuss the recent theoretical and observational progress in addressing the SN Ia progenitor and explosion mechanism in terms of the observables at various stages of the explosion,including rates and delay times,pre-explosion companion stars,ejecta–companion interaction,early excess emission,early radio/X-ray emission from circumstellar material interaction,surviving companion stars,late-time spectra and photometry,polarization signals and supernova remnant properties.Despite the efforts from both the theoretical and observational sides,questions of how the WDs reach an explosive state and what progenitor systems are more likely to produce SNe Ia remain open.No single published model is able to consistently explain all observational features and the full diversity of SNe Ia.This may indicate that either a new progenitor paradigm or an improvement in current models is needed if all SNe Ia arise from the same origin.An alternative scenario is that different progenitor channels and explosion mechanisms contribute to SNe Ia.In the next decade,the ongoing campaigns with the James Webb Space Telescope,Gaia and the Zwicky Transient Facility,and upcoming extensive projects with the Vera C.Rubin Observatory's Legacy Survey of Space and Time and the Square Kilometre Array will allow us to conduct not only studies of individual SNe Ia in unprecedented detail but also systematic investigations for different subclasses of SNe Ia.This will advance theory and observations of SNe Ia sufficiently far to gain a deeper understanding of their origin and explosion mechanism.

Speckle-interferometric Study of Close Visual Binary System HIP 11253(HD 14874)using Gaia(DR2 and EDR3)

We present a comprehensive set of physical and geometrical parameters for each of the components of the close visual binary system HIP 11253(HD 14874).We present an analysis for the binary and multiple stellar systems with the aim to obtain a match between the overall observational spectral energy distribution of the system and the spectral synthesis created from model atmospheres using Al-Wardat's method for analyzing binary and multiple stellar systems.The epoch positions are used to determine the orbital parameters and the total mass.The parameters of both components are derived as:T_(eff)^(a)=6025,T_(eff)^(b)=4710,logg_(a)=4.55,logg_(b)=4.60,R_(a)=1.125 R_(⊙),R_(b)=0.88R_(⊙),L_(a)=1.849 L_(⊙),L_(b)=0.342 L_(⊙).Our analysis shows that the spectral types of the components are F9 and K3.By combining the orbital solution with the parallax measurements of Gaia DR2 and EDR3,we estimate the individual masses using the H-R diagram as M_(a)=1.09 M_(⊙)and M_(b)=0.59 M_(⊙)for using Gaia DR2 parallax and M_(a)=1.10 M_(⊙)and M_(b)=0.61 M_(⊙)for using Gaia EDR3 parallax.Finally,the location of both system's components on the stellar evolutionary tracks is presented.

Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731,TIC72392575,and TIC 318007796

We analyze the frequencies of three known roAp stars,TIC 96315731,TIC 72392575,and TIC 318007796,using the light curves from the Transiting Exoplanet Survey Satellite.For TIC 96315731,the rotational and pulsational frequencies are 0.1498360 day^(-1)and 165.2609 day^(-1),respectively.In the case of TIC 72392575,the rotational frequency is 0.25551 day^(-1).We detect a quintuplet of pulsation frequencies with a center frequency of135.9233 day^(-1),along with two signals within the second pair of rotational sidelobes of the quintuplet separated by the rotation frequency.These two signals may correspond to the frequencies of a dipole mode.In TIC318007796,the rotational and pulsational frequencies are 0.2475021 day^(-1),192.73995 day^(-1),and196.33065 day^(-1),respectively.Based on the oblique pulsator model,we calculate the rotation inclination(i)and magnetic obliquity angle(b)for the stars,which provide the geometry of the pulsation modes.Combining the phases of the frequency quintuplets,the pulsation amplitude and phase modulation curves,and the results of spherical harmonic decomposition,we conclude that the pulsation modes of frequency quintuplets in TIC96315731,TIC 72392575,and TIC 318007796 correspond to distorted dipole mode,distorted quadrupole mode,and distorted dipole mode,respectively.

Photometric Studies of EV Cnc and AH Cnc in the Open Cluster M67

Contact binaries at various stages of evolution unveil various operating mechanisms that drive them.We report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster M67.We observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler observations.The photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q~0.41 and~0.15 with an inclination of i=42°and87°respectively.These solutions suggest that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact binary.The study of O-C variation analysis indicates that for both systems,the period is increasing which suggests the mass transfer is occurring from secondary to primary.In the case of AH Cnc and based on simulations by randomly varying the time of minima to fit the LITE solution,we noted the third body orbital period to be around P_(3)=26.82±2.54 yr,which is different from earlier reported values and conclude that future observations are required to confirm this scenario.We compare these two systems with other similar contact binaries to get an estimate of the final configuration of the respective systems.

Periodic Variation Studies of the Two Short Period W UMa-type Eclipsing Binaries: LX Lyn and V0853 Aur

In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) code.In order to explain their asymmetric LCs,cool starspots on the components were employed.It is suggested that their fill-out degrees are f=12.0%(LX Lyn) and f=26.3%(V0853 Aur).At the same time,we found that LX Lyn is a W-type eclipsing binary(EB) with an orbital inclination of i=84°.88 and a mass ratio of q=2.31.V0853 Aur is also a W-type CEB with a mass ratio of q=2.77 and an orbital inclination of i= 79°.26.Based on all available times of light minimum,their orbital period changes are studied by using the O-C method.The O-C diagram of LX Lyn reveals a cyclic oscillation with a period of about 14.84 yr and an amplitude of 0.0019 days,which can be explained by the light-travel time effect(LTTE) due to the presence of a third body with a minimum mass of0.06M_⊙.For V0853 Aur,it is discovered that the O-C diagram of the system also shows a cyclic oscillation with a period of 9.64 yr and an amplitude of 0.03365 days.The cyclic oscillation of V0853 Aur can be attributed to the LTTE by means of a third body with a mass no less than 3.77M_⊙.The third body may play an important role in the formation and evolution of these systems.

Point-symmetry in SNR G1.9+0.3:A Supernova that Destroyed its Planetary Nebula Progenitor

I analyze a new X-ray image of the youngest supernova remnant(SNR)in the Galaxy,which is the type Ia SNR G1.9+0.3,and reveal a very clear point-symmetrical structure.Since explosion models of type Ia supernovae(SNe Ia)do not form such morphologies,the point-symmetrical morphology must come from the circumstellar material(CSM)into which the ejecta expands.The large-scale point-symmetry that I identify and the known substantial deceleration of the ejecta of SNR G1.9+0.3 suggest a relatively massive CSM of■1M⊙.I argue that the most likely explanation is the explosion of this SN Ia into a planetary nebula.The scenario that predicts a large fraction of SN Ia inside PNe(SNIPs)is the core degenerate scenario.Other SN Ia scenarios might lead to only a very small fraction of SNIPs or none at all.

Investigation of WZ Sge-type Dwarf Nova ASASSN-19oc:Optical Spectroscopy and Multicolor Light Curve Analysis

In this study,we present an investigation of the newly discovered dwarf nova ASASSN-19oc during its superoutburst on 2019 June 2.We carried out detailed UBVRcIc-photometric observations and also obtained a spectrum on day 7 of the outburst,which shows the presence of hydrogen absorption lines commonly found in dwarf nova outbursts.Analysis of photometric data reveals the occurrence of early superhumps in the initial days of observations,followed by ordinary and late superhumps.We have accurately calculated the period of the ordinary superhumps as Pord=0.05681(10)days and determined the periods at different stages,as well as the rate of change of the superhump period(P_(dot)=(5)P/P=8.1×10^(-5)).Additionally,we have derived the mass ratio of the components(q=0.09),and estimated the color temperature during the outburst as~11,000 K,the distance to the system(d=560 pc)and absolute magnitude of the system in outburst(MV=5.3).We have shown that outbursts of this star are very rare:based on brightness measurements on 600 archival photographic plates,we found only one outburst that occurred in 1984.This fact,as well as the properties listed above,convincingly shows that the variable ASASSN-19oc is a dwarf nova of WZ Sge type.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

V0405 Dra:A New Deep and Low Mass Ratio Contact Binary with Extremely Fast Decrease in the Orbital Period

V0405 Dra is a W UMa-type binary star.Based on the TESS data,we have conducted an orbital period study and performed a light curve analysis for the system.The orbital period study reveals that the O-C curve for V0405 Dra exhibits secular decrease at an extremely high rate of d P/dt=-2.71×10^(-6)day year^(-1),along with periodic variations characterized by an amplitude of A_(3)=0.0032 day and a period of P_(3)=1.413 years.The orbital periodic change is possibly due to the light-travel time effect resulting from an additional third body in the system,for which we estimate a minimum mass of M_(3)=0.77M_(⊙).By employing the 2013 version of the Wilson-Devinney(W-D)method to synthesize a light curve,we derived photometric solutions indicating that V0405 Dra is a new deep(f=68.7%)and low-mass ratio(q=0.175)contact binary.The fast decrease in its orbital period is likely caused by mass transfer from the more massive primary star to the less massive secondary star,or due to angular momentum loss.With further mass transfer and loss of angular momentum,the binary will gradually evolve into a tighter contact configuration,eventually leading to a merger into a single star,following the evolutionary paths suggested for such deep and low mass ratio contact binaries.

西藏交通警察道路执法工作的风险与防范

西藏自治区自然、地理与气候环境复杂且特殊,道路交通环境相对恶劣,这导致当地交通警察道路执法工作面临诸多风险,包括警员人身安全和执法效能等风险。对此,文章对西藏交通警察道路执法工作风险进行了调查分析,从地区环境、警员安全意识与技能、执法装备、社会宣传和教育等角度探讨了相关风险的成因,针对性相关风险成因,提出从优化警力配置与道路信息推送、加强警员培训、完善警务装备、加强法治化宣传教育等工作来消除相关风险,以期保障警员安全并改善西藏交通环境。

Morphological Assessment of the Small Intestine of Broilers Fed Dietary Natural Zeolite Including Plant Extract

Many kinds of feed additives （e.g., probiotics, prebiotics, antibiotics, etc.） can be used in chicken diets to stimulate intestinal morphological maturation and, consequently, intestinal function. The aim of this trial was to investigate the possibility that natural zeolite including plant extract （ZEM） could encourage the hypertrophy of intestinal villi and the absorptive function of epithelial cells in broiler chickens. At 7 days old, 64 male Marshall Chunky broilers were divided into four groups, each with four replicates of four chickens. The birds were fed a basal mash diet supplemented with ZEM at 0% （control）, 0.05%, 0.1%, and 0.2% for 42 days. At 49 days old, four chickens from each treatment were killed to obtain intestinal samples. Morphological intestinal assessment was conducted using both a light and a scanning electron microscope. A tendency to increased villus height and cell area could be observed throughout the intestinal segments of the broilers fed ZEM. Particularly, the villus height in the duodenum was significantly increased （P 〈 0.05） in the 0.05% ZEM group when compared with the control group. The area of the villus cells tended to be higher in the ZEM groups in all intestinal regions and showed a significant increase （P 〈 0.05） in the ileal part of the 0.2% ZEM group. Also, the assessment of cells mitosis in the intestinal crypts showed significantly higher numbers （P 〈 0.05） in all levels of ZEM groups in the duodenum and a tendency to increase in value in the jejunum and ileum, as compared with the control group. More protuberated cells and multi-cell clusters were found in the ZEM groups than in the control group, resulting in a rough cellular surface. In conclusion, the present study might suggest that the intestinal villi and epithelial cells on the villus apical surface are hypertrophied in the ZEM groups, and that intestinal villi adapt to enhance their absorption capacity by increasing the absorptive surface area. These results are indicated that ZEM can provide effective nutritive value when used as a feed additive.

A Precise Description of the Electronic Structures and Spin-Allowed Transition Properties of PF and Its Cation:All-Electron Configuration-Interaction Investigations Including Relativistic Effect

The electronic structures of PF and PF＋ are calculated with the high-level configuration interaction method. To improve the precision of calculations, the spin-orbit coupling effect, the scalar relativistic effect, and the Davidson correction（q-Q） are also considered. The spectroscopic parameters of bound states are derived by the electronic structures of PF and PF＋, which are in good accordance with the measurements. The transition dipole moments of spin-allowed transitions are evaluated, and the radiative lifetimes of several A S states of PF and PF＋ are obtained.

Anterior transhepatic approach for total caudate lobectomy including spigelian lobe,paracaval portion and caudate process:A Brazilian experience

To the Editor:Nowadays,because of the infiltration of cholangiocarcinoma to the parenchyma and/or bile ducts of the caudate lobe,the inclusion of caudate lobe combined with a major hepatectomy remains the gold standard approach for a resectable hilar cholangiocarcinoma.Since the last years of the 20th century,some authors have begun to report isolated caudate lobe resection for hepatocellular

Geometric Scaling Analysis of Deep Inelastic Scattering Data Including Heavy Quarks

An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive structure function F2 measured in lepton-hadron scattering experiments at small values of Bjorken x. It is shown that the descriptions of the inclusive structure function F2 and longitudinal structure function FL are improved with the massive analytic structure function, which may imply the gluon saturation effect dominating the parton evolution process at HERA. The inclusion of the heavy quarks prevent the divergence of the lepton-hadron cross section, which plays a significant role in the description of the photoproduction region.

Delayed peripheral treatment with neurotrophin-3 improves sensorimotor recovery after central nervous system injury

Neurotrophin-3 (NT3) is a growth factor found in many body tissues including the heart, intestines, skin, nervous system and in skeletal muscles including muscle spindles (Murase et al., 1994). NT3 is required for the survival, correct connectivity and function of sensory (“proprioceptive”) afferents that innervate muscle spindles;these neurons express receptors for NT3 including tropomyocin receptor kinase C. These proprioceptive afferents are important for normal movement (Boyce and Mendell, 2014) and signals from muscle spindles are important for recovery of limb movement (e.g., after spinal cord lateral hemisection)(Takeoka et al., 2014). The level of NT3 declines in most tissues during postnatal development;its level is low in adult and elderly humans and other mammals (Murase et al., 1994). Elevation of NT3 has been shown to improve outcome in various animal models of neurological disease and injury. For example, many groups have shown that delivery of NT3 directly into the central nervous system promotes recovery after spinal cord injury but this often involved invasive routes or gene therapy (Boyce and Mendell, 2014;Petrosyan et al., 2015;Wang et al., 2018).

Specific Heat of a Unitary Fermi Gas Including Particle-Hole Fluctuation

We investigate the particle-hole fluctuation correction to the specific heat of an ultracold Fermi gas at unitarity within the framework of the non-self-consistent T-matrix approximation in the normal phase. We find good agreement between our theoretical predictions and the experimental data measured by the MIT group, apart from discrepancies near the transition temperature. At high temperature, our calculated specific heat has the tendency to approach the specific heat of the Boltzmann gas.

Theoretical Study on the Spectroscopic Parameters and Transition Properties of MgH Radical Including Spin-orbit Coupling

An accurate theoretical study on the MgH radical is reported by adopting the high-level relativistic MRCI＋Q method with a quintuple-zeta quality basis set. The reliable potential energy curves of the five A-S states of MgH are derived. Then the associated spectroscopic parameters are determined and found to be in good accordance with the available experimental results. The permanent dipole moments （PDMs） and the spin-orbit （SO） matrix elements of A-S states are computed. The results show that the abrupt changes of PDMs and SO matrix elements are attributed to the variations of electronic configurations at the avoided crossing point. The SOC effect leads to the five A-S states split into ten Ω states and results in the double potential well of （2）1//2 state. Finally, the transition properties from the （2）1//2, （1）3//2 and （3）1//2 states to the ground state X2∑＋1//2 transitions are obtained, including the transition dipole moments, Franck-Condon factors and radiative lifetimes.

Evolution Toward the Observational Features of a Stripped Envelope TypeⅡb Supernova in a Binary System

TypeⅡb supernovae(SNeⅡb)that have a thin layer of hydrogen left in their outer envelope have been believed to belong to core collapse supernovae.Mass transfer via Roche lobe overflow can significantly change the nucleosynthesis and surface chemical elements of the progenitors of SNeⅡb.We aim to explore what conditions a close binary can meet with the observational features of SNeⅡb.We find that an observed low mass SNⅡb cannot be produced by a low mass isolated star with M<20,M_(⊙)due to the existence of a thick hydrogen envelope regardless of rotation.Binaries dominate as progenitors in the mass interval(i.e.,M<20 M_(⊙))considered in this paper.The 16 M_(⊙),primary with a 14 M_(⊙) companion in a binary system with~10 days <P_(orb) <720 days can reproduce observational features of SNe Ⅱb(i.e.,T_(eff),log L/L_(⊙),M_(He),M_(H),etc.).With the decrease of the hydrogen-rich envelope mass,the radius of the progenitor shrinks.The associated types of SNⅡb progenitors from RSGs and YSGs to BSGs are closely related to the amount of hydrogen left in the envelopes.Rotation can bring the production of the CNO reaction to the stellar surface at an early phase,which would explain the nitrogen-rich circumstellar material of SN 1993 J and can also explain the large He/H ratio of supernova ejecta.Rotation can increase the corresponding region of the orbital period which can produce an SNⅡb.