There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons.
We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.
The pÀFÀT behavior of 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) was measured from T = (232 to 400) K with pressures up to 10 MPa using a two-sinker densimeter. The measurements extend from low-density vapor to compressed-liquid states, and include the extended critical region. Vapor pressures from T = (250 to 366) K were also measured. The expanded (k = 2) uncertainty in density is (56 3 10 À6 3 F þ 0.0014 kg 3 m À3 ) at near-ambient conditions, increasing to (99 3 10 À6 3 F þ 0.0014 kg 3 m À3 ) at T = 400 K and p = 10 MPa. The maximum uncertainties in temperature and pressure are 0.004 K and (51 3 10 À6 3 p þ 2.0 kPa), respectively. The analysis for density accounts for the force transmission error in the magnetic suspension coupling of the densimeter and includes corrections for vertical density gradients in the measuring cell. These data, together with other data from the literature, have been used to develop an equation of state explicit in the Helmholtz energy covering the fluid region from T = (220 to 410) K with pressures up to 30 MPa. Comparisons to experimental data, including other literature data, are given to establish the accuracy of the equation of state.
This paper presents the application of nonlinear model predictive control (NMPC) to a point absorber wave energy converter (WEC). Model predictive control (MPC) is generally a promising approach for WECs, since system constraints and actuator limits can be taken into account. Moreover, it provides a framework for defining optimal energy capture and it can benefit from predictions. Due to possible nonlinear effects, such as the mooring forces, an NMPC is proposed in this paper, whose performance is compared to that of a linear MPC. Both controllers are supposed to control a nonlinear point absorber model. Computer simulations show that the proposed NMPC is able to optimize the energy capture while satisfying system limits.Index Terms-Nonlinear model predictive control, point absorber, wave energy converter.
The Born cross section for the process e þ e − → pp is measured using the initial state radiation technique with an undetected photon. This analysis is based on datasets corresponding to an integrated luminosity of 7.5 fb −1 , collected with the BESIII detector at the BEPCII collider at center of mass energies between 3.773 and 4.600 GeV. The Born cross section for the process e þ e − → pp and the proton effective form factor are determined in the pp invariant mass range between 2.0 and 3.8 GeV=c 2 divided into 30 intervals. The proton form factor ratio (jG E j=jG M j) is measured in 3 intervals of the pp invariant mass between 2.0 and 3.0 GeV=c 2 .
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