Advancing Hierarchical Equations of Motion for Efficient Evaluation of Coherent Two-dimensional Spectroscopy

To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonlinear optical response function. The new approach is also integrated with optimized hierarchical theory and numerical filtering algorithm. Different configurations of coherent two-dimensional spectroscopy of model excitonic dimer systems are investigated, with focusing on the effects of intermolecular transfer coupling and bi-exciton interaction.

New Realization Method for Airborne SAR Motion Compensation

After analyzing the characteristics of airborne SAR motion deviation in detail, a new realization method for airborne SAR motion compensation based on two-dimensional division processing is described. By combining the division of local tracks in azimuth direction and the division of sub-mapping strips in range direction, the motion deviation will be compensated accurately. Furthermore, both theoretic analysis and simulation result show that by using this method the problems of motion compensation under complex condition with large motion deviation and large mapping strip width can be resolved well.

Disturbance evolution and the nonlinear stability to the basic flows for two-dimensional quasi-geostrophic motion

The status of disturbances of both initial values and parameters in the models is further investigated, the exact explicit estimates on the disturbance energy and disturbance potential enstrophy are given; and while the initial disturbance fields rely only on the initial disturbance potential enstrophy, initial disturbance velocity circulation along the boundary, disturbance parameters, and the nonlinear stability criteria paralleling to Arnold’s second theorem are obtained, and the main results of Mu are generalized.

Numerical Simulation of Viscous Flow Around a Rolling Cylinder with Ship-Like Section

Two-dimensional unsteady incompressible viscous flow around a rolling cylinder with ship-like section is numerically simulated by employing the computational scheme previously developed by the authors, in which the continuity and momentum equations are satisfied simultaneously at each time step for oscillating flow. The numerical results show that the motion of vortices around a rolling ship hull is cyclical. It is found that the location of the vortices is very similar to the existing experimental result. Using these simulation results, we can calculate the roll damping of ships including viscous effects.

Assessment of diaphragmatic function by ultrasonography:Current approach and perspectives

This article reports the various methods used to assess diaphragmatic function by ultrasonography.The excursions of the two hemidiaphragms can be measured using two-dimensional or M-mode ultrasonography,during respiratory maneuvers such as quiet breathing,voluntary sniffing and deep inspiration.On the zone of apposition to the rib cage for both hemidiaphragms,it is possible to measure the thickness on expiration and during deep breathing to assess the percentage of thickening during inspiration.These two approaches make it possible to assess the quality of the diaphragmatic function and the diagnosis of diaphragmatic paralysis or dysfunction.These methods are particularly useful in circumstances where there is a high risk of phrenic nerve injury or in diseases affecting the contractility or the motion of the diaphragm such as neuro-muscular diseases.Recent methods such as speckle tracking imaging and ultrasound shear wave elastography should provide more detailed information for better assessment of diaphragmatic function.

A Solution of Kepler’s Equation

The present study deals with a traditional physical problem: the solution of the Kepler’s equation for all conics (ellipse, hyperbola or parabola). Solution of the universal Kepler’s equation in closed form is obtained with the help of the two-dimensional Laplace technique, expressing the universal functions as a function of the universal anomaly and the time. Combining these new expressions of the universal functions and their identities, we establish one biquadratic equation for universal anomaly (χ) for all conics;solving this new equation, we have a new exact solution of the present problem for the universal anomaly as a function of the time. The verifying of the universal Kepler’s equation and the traditional forms of Kepler’s equation from this new solution are discussed. The plots of the elliptic, hyperbolic or parabolic Keplerian orbits are also given, using this new solution.

1D-2D nanohybrid-based textile strain sensor to boost multiscale deformative motion sensing performance

The development of strain sensors with both superior sensitivity(gauge factor(GF)>100)and broad strain-sensing range(>50%strain)is still a grand challenge.Materials,which demonstrate significant structural deformation under microscale motion,are required to offer high sensitivity.Structural connection of materials upon large-scale motion is demanded to widen strainsensing range.However,it is hard to achieve both features simultaneously.Herein,we design a crepe roll structure-inspired textile yarn-based strain sensor with one-dimensional(1D)-two-dimensional(2D)nanohybrid strain-sensing sheath,which possesses superior stretchability.This ultrastretchable strain sensor exhibits a wide and stable strain-sensing range from microscale to large-scale(0.01%–125%),and superior sensitivity(GF of 139.6 and 198.8 at 0.01%and 125%,respectively)simultaneously.The strain sensor is structurally constructed by a superelastic 1D-structured core elastomer polyurethane yarn(PUY),a novel high conductive crepe roll-structured(CRS)1D-2D nanohybrid multilayer sheath which assembled by 1D nanomaterials silver nanowires(AgNWs)working as bridges to connect adjacent layers and 2D nanomaterials graphene nanoplates(GNPs)offering brittle lamellar structure,and a thin polydopamine(PDA)wrapping layer providing protection in exterior environment.During the stretching/deformation process,microcracks originate and propagate in the GNPs lamellar structure enable resistance to change significantly,while AgNWs bridge adjacent GNPs to accommodate applied stress partially and boost strain.The 1D crepe roll structure-inspired strain sensor demonstrates multifunctionality in multiscale deformative motion detection,such as respiratory motions of Sprague–Dawleyw rat,flexible digital display,and proprioception of multi-joint finger bending and antagonistic flexion/extension motions of its flexible continuum body.

Hydromechanics for the formation and development of radial sandbanks (Ⅰ)——Plane characteristics of tidal flow

Based upon the long-term observation of field data, a two-dimensional numerical model is applied to simulating the tidal flow covering from the neap tide to spring tide in the radial sandbank area in the southern Yellow Sea. From the development of tidal current ridges under the hydrodynamic action, multi-purpose analysis and study are carried out, which include the propagation process of tidal wave, the distributions of tidal wave energy rate and tidal range, the tidal ellipses and traces. It is shown that the tidal current is the major dynamic factor for the formation and development of the radial sandbanks, and the differences of tidal wave energy rate and current strength determine the distinct plane shapes of ridges and troughs in this region.

Dynamic ordering transitions in charged solid

The phenomenon of group motion is common in nature,ranging from the schools of fish,birds and insects,to avalanches,landslides and sand drift.If we treat objects as collectively moving particles,such phenomena can be studied from a physical point of view,and the research on many-body systems has proved that marvelous effects can arise from the simplest individuals.The motion of numerous individuals presents different dynamic phases related to the ordering of the system.However,it is usually difficult to study the dynamic ordering and its transitions through experiments.Electron bubble states formed in a two-dimensional electron gas,as a type of electron solids,can be driven by an external electric field and provide a platform to study the dynamic collective behaviors.Here,we demonstrate that the noise spectrum is a powerful method to investigate the dynamics of bubble states.We observed not only the phenomena of dynamically ordered and disordered structures,but also unexpected alternations between them.Our results show that a dissipative system can convert between chaotic structures and ordered structures when tuning global parameters,which is concealed in conventional transport measurements of resistance or conductance.Moreover,charging the objects to study the electrical noise spectrum in collective motions can be an additional approach to revealing dynamic ordering transitions.