Exercise during chemotherapy is safe and should be encouraged because of beneficial effects on QoL and physical functioning. More research is required to determine the impact on chemotherapy completion rates and prognosis.

Recently, the application of high-Tc superconductors with longitudinal geometry to linear bearings and transportation devices has reached a higher stage of development. For these maglev systems, static stability has already been established; but dynamic stability is still under investigation, since these systems have multiple degrees of freedom and their dynamics are coupled with intricate superconducting phenomena. In this paper, in terms of Newton’s second law, the thermal diffusion equation, and Maxwell’s equations together with a nonlinear power-law constitutive relation, we build a two-dimensional thermal–electromagnetic coupling model to study the dynamics of actual maglev systems composed of a superconductor and a guideway formed by conventional and Halbach arrays of permanent magnets. We assume that the zero-field-cooled superconductor slowly descends to a working height and then its dynamic motion is triggered by an external disturbance or excitation. The results show that when the superconductor has a disturbance-induced initial translational or angular velocity at the working position, vibration and drift phenomena occur simultaneously in the lateral, vertical and rotational directions, and the local temperature rise will aggravate the center of the drift of vibration but will shorten the levitation stabilization time. Lowering the ambient temperature is effective at alleviating the levitation drift. However, a balance between the levitation force and lateral stability should be noted because an excessively low ambient temperature may lead to instability. Additionally, a resonance phenomenon will occur under an external excitation if its frequency is too close to the system’s resonance frequency, which causes a dramatic rise in local temperature and a further large drift for the center of vibration.

For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

We investigate the optical gradient force in 2D hybrid and plasmonic waveguides. By comparing with conventional dielectric waveguides, we show that the optical force can be enhanced by at least 1 order of magnitude in the hybrid and plasmonic waveguides due to strongly enhanced optical fields at the waveguide surfaces. We compare coupled plasmonic waveguides with different geometries, including rectangular, circular, and triangular cross sections and find that the rectangular waveguides provide the strongest force. We also show that the plasmonic enhancement is nonresonant and thus can be used for a broad range of wavelengths.

In the design of maglev systems, the levitation force determines the levitation height and the dynamic stability associated with potential vibrations, especially the offset of the levitation point relative to the working point. However, such two key parameters are often antagonistic: a relatively low dynamic stability comes with a high levitation force, whereas a relatively low levitation force can come with a high dynamic stability. In this paper, we will discuss several strategies to deal with this problem by means of a two-dimensional numerical model based on Newton's second law and Maxwell's equations together with a power-law constitutive relation. The dynamics of maglev systems consisting of a bulk high-temperature superconductor and a Halbach-type permanent-magnet guideway with soft ferromagnets are analyzed. The results show that the drift phenomenon occurs in both vertical and lateral directions triggered by a transverse disturbance, and preloading can alleviate such a phenomenon, but this will lead to a reduction in the levitation force. Improved preloading is effective in enhancing the levitation force without sacrificing the dynamic stability. In some systems, the levitation force and dynamic stability can be further improved by adjusting the soft ferromagnets to an appropriate location in the guideway. Moreover, some guidelines on how the superconducting part should be designed are provided in order to overcome the technical difficulty and reduce the material consumption while at the same time maintaining the dynamic levitation performance.