5G green cellular networks considering power allocation schemes

It is important to assess the effect of transmit power allocation schemes on the energy consumption on random cellular networks. The energy efficiency of 5G green cellular networks with average and water-filling power allocation schemes is studied in this paper. Based on the proposed interference and achievable rate model, an energy efficiency model is proposed for MIMO random cellular networks. Furthermore, the energy efficiency with average and water-filling power allocation schemes are presented, respectively. Numerical results indicate that the maximum limits of energy efficiency are always there for MIMO random cellular networks with different intensity ratios of mobile stations (MSs) to base stations (BSs) and channel conditions. Compared with the average power allocation scheme, the water-filling scheme is shown to improve the energy efficiency of MIMO random cellular networks when channel state information (CSI) is attainable for both transmitters and receivers.Comment: 14 pages, 7 figure

Bis(μ-5-carb­oxy­benzene-1,3-dicarboxyl­ato)-κ3 O 1,O 1′:O 3;κ3 O 3:O 1,O 1′-bis­[(2-phenyl-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthrene-κ2 N 7,N 8)lead(II)]

In the title compound, [Pb2(C9H4O6)2(C19H12N4)2], the PbII atom is five-coordinated by two N atoms from a chelating 2-phenyl-1H-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthrene (L) ligand and three O atoms from two Hbtc ligands (H3btc is benzene-1,3,5-tricarb­oxy­lic acid), resulting in a distorted PbN2O3 coordination. Two PbII atoms are bridged by the Hbtc ligands, forming a discrete centrosymmetric dinuclear complex. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds and π–π inter­actions between the pyridine and imidazole rings, and between the pyridyl rings of the L ligands [centroid–centroid distances = 3.600 (6) and 3.732 (6) Å] lead to a three-dimensional supra­molecular structure

Triply heavy tetraquark states with the QQQˉqˉQQ\bar{Q}\bar{q} configuration

In the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the $QQ\bar{Q}\bar{q}$ tetraquark states and estimated their rough masses in this work. These systems include the explicitly exotic states $cc\bar{b}\bar{q}$ and $bb\bar{c}\bar{q}$ and the hidden exotic states $cc\bar{c}\bar{q}$, $cb\bar{b}\bar{q}$, $bc\bar{c}\bar{q}$, and $bb\bar{b}\bar{q}$. If a state around the estimated mass region could be observed, its nature as a genuine tetraquark is favored. The strong decay patterns shown here will be helpful to the experimental search for these exotic states.Comment: 14 pages, 3 figures and 9 tables. Accepted by Eur. Phys. J.