Expanding proton dripline by employing a number of muons

Through mean-field calculations, we demonstrate that, in a large $Z$ nucleus binding multiple muons, these heavy leptons localize within a few dozen femtometers of the nucleus. The mutual Coulomb interactions between the muons and the protons can lead to a substantial decrease in proton chemical potential, surpassing 1 MeV. These findings allow for expanding the proton-dripline on the nuclear chart in principle, suggesting the possible production of nuclei with Z around 120.Comment: 15 pages, 9 figure

A Well-Balanced Central-Upwind Scheme for the Thermal Rotating Shallow Water Equations

We develop a well-balanced central-upwind scheme for rotating shallow water model with horizontal temperature and/or density gradients---the thermal rotating shallow water (TRSW). The scheme is designed using the flux globalization approach: first, the source terms are incorporated into the fluxes, which results in a hyperbolic system with global fluxes; second, we apply the Riemann-problem-solver-free central-upwind scheme to the rewritten system. We ensure that the resulting method is well-balanced by switching off the numerical diffusion when the computed solution is near (at) thermo-geostrophic equilibria. The designed scheme is successfully tested on a series of numerical examples. Motivated by future applications to large-scale motions in the ocean and atmosphere, the model is considered on the tangent plane to a rotating planet both in mid-latitudes and at the Equator. The numerical scheme is shown to be capable of quite accurately maintaining the equilibrium states in the presence of nontrivial topography and rotation. Prior to numerical simulations, an analysis of the TRSW model based on the use of Lagrangian variables is presented, allowing one to obtain criteria of existence and uniqueness of the equilibrium state, of the wave-breaking and shock formation, and of instability development out of given initial conditions. The established criteria are confirmed in the conducted numerical experiments

Wideband bandpass-to-all-stop reconfigurable filtering power divider with bandwidth control and all-passband isolation

A novel wideband bandpass-to-all-stop reconfigurable filtering power divider is proposed in this study, which allows for four-order bandpass-to-all-stop reconfigurable operating function and equal power division. Its circuit configuration includes the cascaded coupled-line sections with tight coupling to extend the impedance transforming. Furthermore, with the introduction of the half-wavelength open-circuit stubs, which controls the bandwidth, extra transmission poles located at the cut-off frequency are generated, thus resulting in high frequency selectivity. Moreover, by using a single resistor between input coupled-lines, the high all-passband isolation can be achieved. The grounding are then loaded to the output coupled-lines to enable bandpass-to-all-stop operating functionality. For demonstration, a prototype operating at 2 GHz is designed, simulated, and measured with a 15 dB bandwidth of 51%, 19 dB stopband rejection up to 5 GHz, and 14.5 dB all-passband isolation, which shows a good agreement between the simulated and measured results

A Broadband Graphene-Based THz Coupler with Wide-Range Tunable Power-Dividing Ratios

A wide-band coupler based on the graphene with inherent DC-block function and adjustable power-dividing ratios is proposed. This coupler uses three sections of the two-line coupled lines, four sections of the three-line coupled lines, and four graphene stubs (two U-shaped stubs and two rectangular stubs). The graphene stubs allow the coupler to own dynamic surface conductivity, which could be tuned by altering the chemical potentials. The tunable power-dividing ratios could be achieved by varying the chemical potentials applied to the U-shaped graphene stubs and the rectangular graphene elements, respectively. In addition, the widths of two-line coupled lines in the proposed coupler are analyzed to affect the power-dividing ratios in detail. Finally, the power-dividing ratios of the proposed coupler have a variation range from 5.4 to 9.56 dB at 1.75 THz with a flat 90° phase shift. The minimum −10 dB impedance bandwidth is 44 % from 1.47 to 2.3 THz, thus indicating a wide-band performance

Wideband Filtering Power Divider With Ultra-Wideband Harmonic Suppression and Isolation

In this paper, a wideband filtering power divider (PD) with ultra-wideband harmonic suppression and isolation is proposed. The dual coupled-line sections are embedded to the conventional quarter-wavelength transmission lines, which helps to extend the passband of the PD. With the introduction of the short-circuit stubs shunted at the output ports and the coupled lines with the open-circuit stubs, the ultra-wide stopband can be implemented more efficiently, thus resulting in five transmission zeros from 2 to 6 GHz. Furthermore, the improved isolation structure with series connected a resistor and a capacitor can be utilized to realize the ultra-wide isolation frequency band. Using a single resistor between two output ports, we have achieved an excellent in-band isolation. For demonstration, a wideband filtering PD operating at 1 GHz with a 20-dB bandwidth of 50% and an ultra-wide stopband better than 20 dB from 2 to 6 GHz is designed, fabricated, and measured. The measured results agree well with the anticipation