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We investigate the dynamics of beating solitons in a two-component Bose–Einstein condensate with tunable Rabi coupling strength. Our results demonstrate that the balance between transition and beating effects permits the emergence of a novel family of asymmetric solitons in the symmetric physical settings. We derive the exact analytical solutions for them, which primarily consist of one bright soliton and one dark soliton element. The analytical solutions provide us with precise balance conditions required for the formation of asymmetric solitons. We also show that the degree of asymmetry can be effectively manipulated by adjusting the background density flow of dark soliton element, initial relative phase between two soliton elements, and their width. Furthermore, we discuss the oscillation behavior of asymmetric solitons in a harmonic potential, and the interaction between them. [ABSTRACT FROM AUTHOR]

The experiment was used fermentation bed technology to study the effect of fermentation bed on diarrhea rate, growth performance and blood physicochemical indexes of lambs in winter. Three batches of experiments were carried out in a row, and 30 hybrid ewes who had just given birth and gave birth to two lambs in each batch were randomly assigned to two closed houses with windows and the same building structure, one floor was transformed into a fermentation bed (experimental group), and the other was used as a control group. The lambs were fed in a single pen for 7 d and then transferred out. Each group was randomly divided into three pens, transferred to semi-open houses, and continued to be fed until weaning at 60 d. The results showed that on 1~7 d, the diarrhea rate of lambs in experimental group was significantly lower than that in control group (P<0.05). From birth to weaning, the diarrhea rate and mortality of lambs in experimental group were decreased by 2.49% and 2.95% compared with control group (P<0.05). On 7 d of experiment, the body height, body length and chest circumference of lambs in experimental group were increased by 1.71, 0.56, 0.66 cm compared with control group, respectively (P<0.05). On 8~30 d, the average daily gain of lambs in experimental group was increased by 22.59% compared with control group ( P<0.05). The average daily gain of experimental group was significantly higher than that of control group during the whole experiment period (1~60 d) (P<0.05). At 60 d of age, the body weight of lambs in experimental group was increased by 13.42% compared with control group ( P<0.05). The percentage of lymphocyte in whole blood of lambs in experimental group was significantly higher than that in control group (P<0.05), and the content of GLU, TP and GLB in serum were increased by 8.45%, 3.34% and 10.49% compared with control group, respectively (P<0.05). The study indicates that using a fermentation bed feeding mode within 7 d of birth can reduce the rate of diarrhea and mortality before weaning, and improve the apparent digestibility and blood physicochemical indicators of lambs. [ABSTRACT FROM AUTHOR]

We report a kind of kink-like breathers in one-dimensional Bose-Einstein condensates (BECs) with helicoidal spin-orbit coupling (SOC), on whose two sides the background densities manifest obvious difference (called kink amplitude). The kink amplitude and shape of breather can be adjusted by the strength and period of helicoidal SOC, and its atomic number in two components exchanges periodically with time. The SOC has similar influence on the kink amplitude and the exchanged atomic number, especially when the background wave number is fixed. It indicates that the oscillating intensity of breather can be controlled by adjusting initial kink amplitude. Our work showcases the great potential of realizing novel types of breathers through SOC, and deepens our understanding on the formation mechanisms of breathers in BECs. [ABSTRACT FROM AUTHOR]

For a scalar integrable model, it is generally believed that the solitons interact with each other elastically, for instance, multi-bright solitons from the nonlinear Schrödinger equation and the Korteweg-de Vries equation, etc. We obtain double-valley dark solitons from the defocusing Hirota equation by the Darboux transformation. Particularly, we report a remarkable phenomenon for the inelastic interaction of the double-valley dark solitons, in contrast to the solitons interacting with each other elastically for a scalar integrable model in previous works. Furthermore, we give the explicit conditions for the elastic collision based on the asymptotic analysis results. It is shown that the double-valley dark solitons could also admit elastic interaction under the special parameters settings. [ABSTRACT FROM AUTHOR]

In this work, we explore systematically various SO(2)-rotation-induced multiple dark–dark (DD) soliton breathing patterns obtained from stationary and spectrally stable multiple dark–bright (DB) and DD waveforms in trapped one-dimensional, two-component atomic Bose–Einstein condensates. The stationary states stemming from the associated linear limits (as the eigenfunctions of the quantum harmonic oscillator problem) are parametrically continued to the nonlinear regimes by varying the respective chemical potentials, i.e. from the low-density linear limits to the high-density Thomas–Fermi (TF) regimes. We perform a Bogolyubov–de Gennes spectral stability analysis to identify stable parametric regimes of these states, finding a wide range of stability intervals in the TF regimes for all of the states considered herein. Upon applying an SO(2)-rotation to stable steady states, one-, two-, three-, four-, and many DD soliton breathing patterns are observed in the numerical simulations. Furthermore, analytic solutions up to three DB solitons in the homogeneous setting, and three-component systems are also investigated. [ABSTRACT FROM AUTHOR]

We study numerically the evolutions of perturbations at critical points between modulational instability and stability regimes. It is demonstrated that W-shaped solitons and rogue waves can be both excited from weak resonant perturbations at the critical points. The rogue wave excitation at the critical points indicates that rogue wave comes from modulation instability with resonant perturbations, even when the baseband modulational instability is absent. The perturbation differences for generating W-shaped solitons and rogue waves are discussed in detail. These results can be used to generate W-shaped solitons and rogue waves controllably from weak perturbations. [ABSTRACT FROM AUTHOR]

Dark solitons are common topological excitations in a wide array of nonlinear waves. The dark soliton excitation energy is crucial for exploring dark soliton dynamics and is necessarily calculated in a renormalized form due to its existence on a finite background. Despite its tremendous importance and success, the renormalized energy form was at first only suggested with no detailed derivation, and was then "derived" in the grand canonical ensemble. We revisit this fundamental problem and provide an alternative and intuitive derivation of the energy form from the fundamental field energy by utilizing a limiting procedure that conserves number of particles. Our derivation yields the same result, thus putting the dark soliton energy form on a solid basis. [ABSTRACT FROM AUTHOR]

We investigate tunneling behavior between two bright solitons in a Bose-Einstein condensate with attractive contact interactions between atoms. The explicit tunneling properties including tunneling particles and oscillation period are described analytically, which indicates that the periodic tunneling form is a nonlinear Josephson type oscillation. The results suggest that the breathing behavior of solitons comes from the tunneling mechanism in an effective double-well potential, which is quite different from the modulational instability mechanism for Akhmediev breather and K-M breather. The relative phase between the two solitons has no effects on the tunneling period and particle exchanging rate. Furthermore, we obtain a phase diagram for two-soliton interaction which admits tunneling property, particle-like property, interference property, and a resonant interaction case. The explicit conditions for them are clarified based on the defined critical distance $$d_c$$ and spatial interference period D. [ABSTRACT FROM AUTHOR]

Typical Al-Ti-B master alloys are good inoculant for aluminum alloys, which have shown obvious dependence on some alloying elements. In this work, in situ AlN-TiN-TiB2/Al composite refiner was successfully prepared by nitrogen alloying based on an Al-8Ti-1B melt. It is found that the refining, tensile strength, yield strength, and hardness of the pure aluminum modified by in situ AlN-TiN-TiB2/Al composite inoculant were all obviously improved. The enhanced refining and reinforcing effects of the refiner can be attributed to the following aspects: the formation of AlN and TiN particles, the homogeneous distribution of AlN, TiN, and TiB2 particles and the miniaturization of Al3Ti phases. The above three factors are all caused by nitridation and have a combining effect for improving the nucleation rate of α-Al. [ABSTRACT FROM AUTHOR]

We study on non-linear localized waves on continuous wave background in a dispersion and non-linearity management fibre. We find a stable supercontinuum pulse can be generated from a small modulation on continuous wave in a proper management way, for which the pulse spectrum width and its growth rate can be controlled well by the management parameters. Additionally, we demonstrate a Kuznetsov–Ma breather like non-linear localized wave can exist in a periodic dispersion management fibre, and its spectrum evolution is distinctive from the Kuznetsov–Ma breather’s. [ABSTRACT FROM AUTHOR]

Interference patterns associated with soliton-soliton interaction are investigated in detail. We find that the temporal and spatial interference patterns exhibit quite different characteristics through performing the density calculation and asymptotic analysis technic on the well-known two-soliton solution. The period of the spatial interference pattern is determined by the relative velocity of the solitons, and the temporal pattern behavior is determined by the peak amplitudes and the kinetic energy of the solitons. Analytical expressions for the periods of the interference patterns are obtained. A method for classifying the nonlinearity of many nonlinear systems is proposed. As an example, we discuss what can be read out from the nonlinear interference pattern between solitons in an ultra-cold atom system. [ABSTRACT FROM AUTHOR]

We investigate the role of asymmetry in the geometric phase of an ultracold bosonic atom-heteronuclear molecule system where the asymmetry denotes the particle-number imbalance between two atomic species. Based on the mean-field approach, we derive the analytical expression of the geometric phase and confirm it by our numerical simulations. It is found that the geometric phase strongly depends both on the atom-number imbalance and the nonlinear particle interaction. We show that the geometric phase can be dramatically enhanced by increasing the imbalance or the repulsive interaction strength. For the symmetric case, a discontinuous behavior for the first-order derivative of the ground-state geometric phase at a critical point is seen which gives a distinct signal of a phase transition from mixed atom-molecule phase to pure molecule phase. The virtual magnetic field interpretation for the geometric phase is also given. [ABSTRACT FROM AUTHOR]

We investigate bright, dark and two rogue waves in two-component Bose-Einstein condensates. It is found that one rogue wave of a new structure that contains two humps and two valleys around one center in the temporalspatial distribution interacts with the conventional rogue wave. We present an effective way to obtain long-lived rogue waves through managing the nonlinear interaction with modulating trapping frequency and interchange atoms between thermal clouds and condensates. The results provide many possibilities to manipulate rogue waves experimentally in the condensate system. [ABSTRACT FROM AUTHOR]

To detect food E. coli O157:H7 contamination rapidly and accurately, it is essential to prepare high specific monoclonal antibodies (mAbs) against the pathogen. Cyclophosphamide (Cy)-mediated subtractive immunization strategy was performed in mice to generate mAbs that react with E. coli O157:H7, but not with other affiliated bacteria. Specificity of 19 mAbs was evaluated by ELISA and/or dot-immunogold filtration assay (DIGFA). Immunogloubin typing, affinity and binding antigens of 5 selected mAbs were also analysed. MAbs 1D8, 4A7, 5A2 were found to have high reactivity with E. coli O157:H7 and no cross-reactivity with 80 other strains of bacteria including Salmonella sp., Shigella sp., Proteus sp., Yersinia enterocolitica, Staphylococcus aureus, Klebsiella pneumoniae, Citrobacter freundii and other non-E. coli O157:H7 enteric bacteria. Their ascetic titers reached 1:106 with E. coli O157:H7 and affinity constants ranged from 1.5761010 to 2.7961010 L/ mol. The antigens recognized by them were different localized proteins. Furthermore, immune-colloidal gold probe coated with mAb 5A2 could specifically distinguish minced beef contaminated by E. coli O157:H7 from 84 other bacterial contaminations. The Cy-mediated subtractive immunization procedure coupled with hybridoma technology is a rapid and efficient approach to prepare discriminatory mAbs for detection of E. coli O157:H7 contamination in food. [ABSTRACT FROM AUTHOR]

We investigate linear interference effects between a nonlinear plane wave and bright solitons, which are admitted by a pair-transition coupled two-component Bose-Einstein condensate. We demonstrate that the interference effects can induce several localized waves possessing distinctive wave structures, mainly including anti-dark solitons, W-shaped solitons, multi-peak solitons, Kuznetsov-Ma like breathers, and multi-peak breathers. Specifically, the explicit conditions for them are clarified by a phase diagram based on the linear interference properties. Furthermore, the interactions between these localized waves are discussed. The detailed analysis indicates that the soliton-soliton interaction induced phase shift brings the collision between these localized waves which can be inelastic for solitons involving collision and can be elastic for breathers. These characters come from the fact that the profile of solitons depends on the relative phase between bright solitons and a plane wave, and the profile of breathers does not depend on the relative phase. These results would motivate more discussions on linear interference between other nonlinear waves. Specifically, the solitons or breathers obtained here are not related to modulational instability. The underlying reasons are discussed in detail. In addition, possibilities to observe these localized waves are discussed in a two species Bose-Einstein condensate. [ABSTRACT FROM AUTHOR]