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The adaptive finite element material point method (AFEMP) takes advantages of both finite element method (FEM) and material point method (MPM), suitable for dealing with extreme deformation problems. Use AFEMP to simulate the penetration of steel spheres and bullets into ballistic gelatin at high velocities to better understand the damage effects caused by the projectiles to biological soft tissue. Gelatin are initially divided into finite elements and then the elements are converted into MPM particles using the characteristic length ratio and the main direction maximum stretch ratio of element as conversion criteria in order to avoid elements distortion during the solution process. The effect of the background grid size on the calculation results is studied, and the background grid should be slightly smaller than finite element so that it can better describe the severely compressed gelatin. Numerical results are presented to validate the accuracy of AFEMP program of this work, and it can better simulate the temporary cavity than the commercial software LS-DYNA. The propagation of pressure wave can cause crushing and tearing damage of the gelatin. The damaged area caused by pressure wave is larger than the temporary cavity, and its shape is closer to the cylinder with the increase of the speed of the steel sphere. The velocity and shape of projectile play a decisive role in the damage effects. [ABSTRACT FROM AUTHOR]

Abstract We investigate the breathers and their interactions via the N th binary Darboux transformation for the coupled nonlinear Schrödinger equations with negatively coherent coupling in a weakly birefringent fiber, where N is a positive integer. For the two interacting optical modes, we obtain four types of the vector breathers with different structures, i.e., the single- and double-hump Kuznetsov–Ma breathers, double-hump Akhmediev breathers, kink-type breathers, as well as their interactions. Interaction with the varying background amplitude, i.e., interaction between the single-hump/double-hump Kuznetsov–Ma breather and kink-type breather, is pointed out. Interaction between the double-hump Kuznetsov–Ma breather and double-hump Akhmediev breather is elastic with the invariant background amplitude, while interaction between the single-hump Kuznetsov–Ma breather and double-hump Akhmediev breather is inelastic. Breathers and rogue waves can coexist and interact with each other. During the interaction between an eye-shaped rogue wave and a breather, eye-shaped rogue wave can split to a pair of the beak-type rogue waves. Those waves correspond to the slowly varying envelopes of two interacting optical modes in a weakly birefringent fiber. [ABSTRACT FROM AUTHOR]

The magneto-optical properties of simple hexagonal graphite exhibit rich beating oscillations, which are dominated by the field strength and photon energy. The former has a strong effect on the intensity, the energy range of the beating and the number of groups, and the latter modulates the total group numbers of the oscillation structures. The single-particle and collective excitations are simultaneously presented in the magnetoreflectance spectra and can be precisely distinguished. For the loss function and reflectance, the beating pattern of the first group displays stronger intensities and broader energy range than other groups. Simple hexagonal graphite possesses unique magneto-optical characteristics that can serve to identify other bulk graphites. [ABSTRACT FROM AUTHOR]

Taeniasis and cysticercosis, which are caused by Taenia saginata , Taenia solium and Taenia asiatica , are zoonotic parasitic infections with a significant disease burden worldwide. There is consensus amongst experts that T. saginata is a common tapeworm that causes taeniasis in humans as opposed to cysticercosis. This case study of a middle-aged Tibetan man conducted in 2021 challenges the prevailing notion that T. saginata exclusively causes taeniasis and not cysticercosis by documenting symptoms and laboratory studies related to both taeniasis and multiple cysticercosis. The patient's medical record with the symptoms of taeniasis and cysticercosis was reviewed, and the tapeworm's proglottids and cyst were identified from the patient by morphological evaluation, DNA amplification and sequencing. The patient frequently experienced severe headaches and vomiting. Both routine blood screenings and testing for antibodies against the most common parasites were normal. After anthelmintic treatment, an adult tapeworm was found in feces, and medical imaging examinations suggested multiple focal nodules in the brain and muscles of the patient. The morphological and molecular diagnosis of the proglottids revealed the Cestoda was T. saginata. Despite the challenges presented by the cyst's morphology, the molecular analysis suggested that it was most likely T. saginata. This case study suggests that T. saginata infection in humans has the potential to cause human cysticercosis. However, such a conclusion needs to be vetted by accurate genome-wide analysis in patients with T. saginata taeniasis associated with cysts. Such studies shall provide new insights into the pathogenicity of T. saginata. [ABSTRACT FROM AUTHOR]

Coupled nonlinear Schrödinger system with negative coherent coupling in a weakly birefringent fiber is hereby studied. For the slowly varying envelopes of two interacting optical modes, analytic soliton solutions with the coalescence of eigenvalues are derived. Based on the asymptotic analyses, we find three kinds of the counterpropagating solitons, indicating that they consist of the so-called nondegenerate or degenerate solitons. From the plane-wave seed solutions with the certain eigenvalues, single-peak rogue waves are exhibited as well. [ABSTRACT FROM AUTHOR]

The article focuses on the increasingly aging demographic of China and presents information on the 99 Life Care Fund that was founded by Wang Bailing. The Fund, that was launched on May 12, 2011, is said to be the only public fund in the country that is focused on the elderly. Wang says service for the elderly is multifaceted in its scope and China is facing a problem that it will get old before getting affluent. According to statistics released by China National Committee on Ageing, the country's ageing population was 167 million in 2009.

The coalescence between the advancing liquid meniscus and multiple droplets is usually encountered in the liquid filling process and photothermal effect based microdevices. To shed light on how the coalescence between the advancing liquid meniscus and multiple droplets affects the liquid meniscus advancement, its dynamic behaviors are numerically investigated using the coupled level set and volume-of-fluid (CLSVOF) method along with the continuum surface force (CSF) model in this study. Particular attention is paid to the dynamic interfacial phenomena during the coalescence process. The effect of the droplet and its volume distributions is also investigated. The simulation results show that the coalescence between the advancing liquid meniscus and each droplet is able to instantly accelerate the original liquid flow as a result of the induced concave meniscus with large curvature. As compared to the coalescence with a single droplet, the fluctuation and deformation of the interface is stronger in the case of simultaneous coalescence with multiple droplets, which can further lower the average liquid pressure and thus show more significant advancement of the liquid flow. The velocity increment ratio is the largest when four droplets simultaneously coalesce with the advancing liquid meniscus. It is shown that the coalescence with large droplet can result in large velocity increment ratio because more surface energy is supplied. Large length of the advancing liquid segment before its coalescence with the droplets can weaken the advancing effect. It is also found that the overall variation trend of the simulation results is in agreement with that of the experimental results. [ABSTRACT FROM AUTHOR]

A lattice Boltzmann model for high-speed compressible viscous flows is presented based on the double-distribution-function lattice Boltzmann method proposed by Li et al. (2007). The D2Q17 circle function is introduced to take into account first to fourth order constraints of density equilibrium distribution function, in order for better consistency in the heat flux and the energy dynamics. The corresponding total energy equilibrium distribution function is formed. The present model is tested through three problems, i.e., the Riemann problem, regular shock reflection problem and supersonic boundary layer problem. We also observe improved performance of the new model for a supersonic boundary layer problem in comparison to the original coupled double-distribution-function lattice Boltzmann method. [ABSTRACT FROM AUTHOR]

In this study, a fully nonlinear method, in the time domain, is used to simulate ship motion caused by large waves, and the problem of wave climbing along the freeboard in large waves is studied. The method is based on a three-dimensional potential flow theory. Further, the nonlinear free surface condition is adopted, the incident potential and disturbance potential are separated from each other, and the problem of determining the disturbance potential is established. In order to consider the nonlinearity of the body surface, the wetted surface area of the hull is continuously updated with time and extended along the tangential direction of the uppermost grid when the free liquid level exceeds the height of the hull deck. In addition, an artificial damping layer is provided to eliminate the reflection of waves at the outflow boundary. Under the fully nonlinear boundary conditions, the perturbation potential is solved by the Rankine source boundary element method. Introducing auxiliary functions solves the coupling problem between motion and load in the process of solving rigid body motion equations. After the solution is completed, it is updated to the next time step using the Runge-Kutta 4th order method. In this study, the convergence of the computational grid of the numerical model is firstly verified. Then, the motion and load responses of a zero-speed ship in the regular wave of unit wave amplitude using this method are examined and compared with the linear method. The latter verifies the accuracy of this method in the linear field. Afterwards, in order to investigate the superiority of the fully nonlinear method when the nonlinear phenomenon is strong, the motion and load of the ship in the large amplitute wave are simulated and the influence of the nonlinear phenomenon is analyzed. Finally, the phenomenon of wave climbing generated in high waves is analyzed, and the relationship between wave and water heights is evaluated. [ABSTRACT FROM AUTHOR]

• Project selection mechanism is incorporated into threshold public goods game. • Multiple updating rules in project selection promote cooperation. • Higher cooperation corresponds to larger preferred project scale. How evolution favors cooperation is a fundamental issue in social and economic systems. In the business world, actively selecting a suitable project is usually helpful for a businessman to be in an advantageous position. By incorporating project selection mechanism into the threshold public goods game, we have investigated the coupling effect of mutation and imitation in updating one's preferred project scale on the evolution of cooperation. Compared with the situation where there is no project selection mechanism, the existence of project selection may suppress or promote cooperation depending upon different updating rules. There exists a critical ratio of the imitators in the population, below which cooperation is suppressed while above which cooperation is promoted. With the coevolving of individual strategies and preferred project scales, a higher level of cooperation corresponds to a larger average value of the preferred project scales. A theoretical analysis indicates that, as most of the individuals are mutants, the coevolving process is governed by the mutation process, which leads to a smaller average value of the preferred project scales and a lower level of cooperation. As most of the individuals are imitators, the coevolving process is governed by the coupling of the mutation and imitation processes, which leads to a larger average value of the preferred project scales and a higher level of cooperation. As all the individuals are imitators, the coevolving process is governed by the imitation process, which leads to an intermediate average value of the preferred project scales and an intermediate level of cooperation. [ABSTRACT FROM AUTHOR]

Highlights • Under investigation is a higher-order nonlinear Schrodinger system for the simultaneous propagation of two ultrashort optical pulses in an optical fiber. • With respect to the two-component electric fields, infinitely-many conservation laws and N-fold binary Darboux transformation are derived via the symbolic computation. • Nondegenerate one dark–dark soliton which is black or gray in each component is obtained. epsilon has no relation with the soliton amplitudes in each component, but has a linear correlation with the soliton velocities. • Overtaking and head-on interactions between the two dark–dark solitons as well as the bound state are depicted. With the decreasing value of sigma_1, the gray solitons' amplitudes increase, but the black solitons' amplitudes decrease. With the decreasing value of sigma_2, the gray solitons' amplitudes increase, but the black solitons' amplitudes do not change. • Interaction among the three overtaking solitons and interaction between a bound state and one soliton are displayed. We find that the interactions between the two solitons and among the three solitons are elastic. Abstract Optical fiber communication system is one of the core supporting systems of the modern internet age. In this paper, under investigation is a higher-order nonlinear Schrödinger system for the simultaneous propagation of two ultrashort optical pulses in an optical fiber. Based on the Lax pair, with respect to the two-component electric fields, infinitely-many conservation laws and one/ N -fold binary Darboux transformations are derived, where N = 2 , 3 , .... Solitons are discussed: (1) Nondegenerate one dark–dark soliton, which is black or gray in each component, is obtained. ϵ has no relation with the soliton amplitude in each component, but has a linear correlation with the soliton velocities, where ϵ, σ 1 and σ 2 are the constant coefficients in the system; (2) Overtaking and head-on interactions between the two dark–dark solitons as well as the bound state are depicted. With the decreasing value of σ 1 , the gray solitons' amplitudes increase, but the black solitons' amplitudes decrease. With the decreasing value of σ 2 , the gray solitons' amplitudes increase, but the black solitons' amplitudes do not change; (3) Interaction among the three overtaking solitons and interaction between a bound state and one soliton are displayed. We find that the interactions between the two solitons and among the three solitons are elastic. [ABSTRACT FROM AUTHOR]

Facing a heavy task, any single person can only make a limited contribution and team cooperation is needed. As one enjoys the benefit of the public goods, the potential benefits of the project are not always maximized and may be partly wasted. By incorporating individual ability and project benefit into the original public goods game, we study the coupling effect of the four parameters, the upper limit of individual contribution, the upper limit of individual benefit, the needed project cost and the upper limit of project benefit on the evolution of cooperation. Coevolving with the individual-level group size preferences, an increase in the upper limit of individual benefit promotes cooperation while an increase in the upper limit of individual contribution inhibits cooperation. The coupling of the upper limit of individual contribution and the needed project cost determines the critical point of the upper limit of project benefit, where the equilibrium frequency of cooperators reaches its highest level. Above the critical point, an increase in the upper limit of project benefit inhibits cooperation. The evolution of cooperation is closely related to the preferred group-size distribution. A functional relation between the frequency of cooperators and the dominant group size is found. [ABSTRACT FROM AUTHOR]

In this paper, the investigation is on a three-component coupled nonlinear Schrödinger (NLS) system which governs the wave evolution in a multimode optical fiber. We construct a Darboux transformation (DT) induced via a rank-two projection matrix, and then derive an (N , m) -generalized DT and the N th-order solution, where the positive integers N and m denote the numbers of iterative times and distinct spectral parameters, respectively. Focusing on the N th-order solution on the nonzero–zero–zero background, we derive two kinds of waves which could not be derived by the DT induced via a rank-one projection matrix, that is, the so-called fundamental nonlinear wave (N = 1) and degenerate fundamental nonlinear wave (N = 2 and m = 1). Via the asymptotic analysis, we find that the fundamental nonlinear wave is the nonlinear superposition of two dark–bright–bright solitons and a breather/Kuznetsov–Ma​ breather/rogue wave; and the degenerate fundamental nonlinear wave is the nonlinear superposition of four dark–bright–bright solitons and two breathers/two Kuznetsov–Ma​ breathers/a second-order rogue wave. Since such phenomena are not admitted for the one-component NLS equation and two-component coupled NLS system, they are more useful to understand the three-component coupled NLS system than what the latter two models admit. For other three-component coupled systems, more phenomena may be expected when the rank of projection matrix used to construct a DT is two rather than one, because our study presents an example. [ABSTRACT FROM AUTHOR]

Optical fiber communication plays an important role in the modern communication. In this paper, we investigate a variable-coefficient coupled Hirota system which describes the vector optical pulses in an inhomogeneous optical fiber. With respect to the complex wave envelopes, we construct a Lax pair and a Darboux transformation, both different from the existing ones. Infinitely-many conservation laws are derived based on our Lax pair. We obtain the one/two-fold bright-bright soliton solutions, one/two-fold bright-dark soliton solutions and one/two-fold breather solutions via our Darboux transformation. When α (t) , β (t) and δ (t) are the trigonometric functions, we present the bright-bright soliton, bright-dark soliton and breather which are all periodic along the propagation direction, where α (t) , β (t) and δ (t) represent the group velocity dispersion, third-order dispersion and nonlinear terms of the self-phase modulation and cross-phase modulation. Interactions between the two bright-bright soliton, two bright-dark solitons and two breathers are presented. Bound state of the two bright-bright solitons is formed. Widths and velocities of the two bright-bright solitons do not change but their amplitudes change after their interaction via the asymptotic analysis. Periods of the bright-dark solitons decrease when the periods of the trigonometric α (t) , β (t) and δ (t) decrease. [ABSTRACT FROM AUTHOR]