Effects of Phi and σ∗\sigma^{*}-meson on properties of hyperon stars including Δ\Delta resonance

In this work, we study the properties of neutron stars using the linear Relativistic Mean-Field (RMF) theory and consider multiple degrees of freedom inside neutron stars, including hyperons and $\Delta$ resonances. We investigate different coupling parameters $x_{\sigma \Delta}$ between $\Delta$ resonances and nucleons and compare the differences between neutron stars with and without strange mesons $\sigma^*$ and $\phi$. These effects include particle number distributions, equations of state (EOS), mass-radius relations, and tidal deformabilities. To overcome the "hyperon puzzle," we employ the $\sigma-cut$ scheme to obtain neutron stars with masses up to $2M_{\odot}$. We find that strange mesons appear at around 3$\rho_0$ and reduce the critical density of baryons in the high-density region. With increasing coupling parameter $x_{\sigma \Delta}$, the $\Delta$ resonances suppress hyperons, leading to a shift of the critical density towards lower values. The early appearance of $\Delta$ resonances may play a crucial role in the stability of neutron stars. Strange mesons soften the EOS slightly, while $\Delta$ resonances predominantly soften the EOS in the low-density region. By calculating tidal deformabilities and comparing with astronomical observation GW170817, we find that the inclusion of $\Delta$ resonances decreases the radius of neutron stars.Comment: 10 pages, 9 figure

Kaon Meson Condensation and Δ\Delta resonance of Hyperonized Star with relativistic mean-field model

We study the equation of state of dense baryon matter within the relativistic mean-field model, and we include ${\Delta}$(1232) isobars into IUFSU model with hyperons and consider the possibility of kaon meson condensation. We find that it is necessary to consider the $\Delta$ resonance state inside the massive neutron star. The critical density of Kaon mesons and hyperons is shifted to a higher density region, in this respect an early appearance of $\Delta$ resonances is crucial to guarantee the stability of the branch of hyperonized star with the difference of the coupling parameter $x_{\sigma \Delta}$ constrained based on the QCD rules in nuclear matter. The $\Delta$ resonance produces a softer equation of state in the low density region, which makes the tidal deformability and radius consistent with the observation of GW170817. As the addition of new degrees of freedom will lead to a softening of the equation of state, the ${\sigma}$-cut scheme, which states the decrease of neutron star mass can be lowered if one assumes a limited decrease of the ${\sigma}$-meson strength at ${\rho_B}$($\rho_B > \rho_0$), finally we get a maximum mass neutron star with $\Delta$ resonance heavier than 2$M_{\odot}$.Comment: 10 pages, 9 figure

From the conventional MIMO to massive MIMO systems: performance analysis and energy efficiency optimization

The main topic of this thesis is based on multiple-input multiple-output (MIMO) wireless communications, which is a novel technology that has attracted great interest in the last twenty years. Conventional MIMO systems using up to eight antennas play a vital role in the urban cellular network, where the deployment of multiple antennas have significantly enhanced the throughput without taking extra spectrum or power resources. The massive MIMO systems “scales” up the benefits that offered by the conventional MIMO systems. Using sixty four or more antennas at the BS not only improves the spectrum efficiency significantly, but also provides additional link robustness. It is considered as a key technology in the fifth generation of mobile communication technology standards network, and the design of new algorithms for these two systems is the basis of the research in this thesis. Firstly, at the receiver side of the conventional MIMO systems, a general framework of bit error rate (BER) approximation for the detection algorithms is proposed, which aims to support an adaptive modulation scheme. The main idea is to utilize a simplified BER approximation scheme, which is based on the union bound of the maximum-likelihood detector (MLD), whereby the bit error rate (BER) performance of the detector for the varying channel qualities can be efficiently predicted. The K-best detector is utilized in the thesis because its quasi- MLD performance and the parallel computational structure. The simulation results have clearly shown the adaptive K-best algorithm, by applying the simplified approximation method, has much reduced computational complexity while still maintaining a promising BER performance. Secondly, in terms of the uplink channel estimation for the massive MIMO systems with the time-division-duplex operation, the performance of the Grassmannian line packing (GLP) based uplink pilot codebook design is investigated. It aims to eliminate the pilot contamination effect in order to increase the downlink achievable rate. In the case of a limited channel coherence interval, the uplink codebook design can be treated as a line packing problem in a Grassmannian manifold. The closed-form analytical expressions of downlink achievable rate for both the single-cell and multi-cell systems are proposed, which are intended for performance analysis and optimization. The numerical results validate the proposed analytical expressions and the rate gains by using the GLP-based uplink codebook design. Finally, the study is extended to the energy efficiency (EE) of the massive MIMO system, as the reduction carbon emissions from the information and communication technology is a long-term target for the researchers. An effective framework of maximizing the EE for the massive MIMO systems is proposed in this thesis. The optimization starts from the maximization of the minimum user rate, which is aiming to increase the quality-of-service and provide a feasible constraint for the EE maximization problem. Secondly, the EE problem is a non-concave problem and can not be solved directly, so the combination of fractional programming and the successive concave approximation based algorithm are proposed to find a good suboptimal solution. It has been shown that the proposed optimization algorithm provides a significant EE improvement compared to a baseline case

Effect of Different Debranning Degrees on the Qualities of Whole Wheat Flour and Chinese Steamed Bread

Abstract: Strong gluten, middle-strong gluten and middle gluten wheat were used as raw materials to obtain whole wheat flour by dry debranning process, and the effect of different debranning degrees on the quality of wheat kernel, whole wheat flour and Chinese steamed bread was evaluated. The results showed that the ash content, hardness index and thousand kernel weight of wheat kernels were decreased with increasing debranning degree by 0.17%, 1.0–1.5 and 1.74–1.82 g, respectively, whereas the volume weight was increased by 22.0–23.4 g/L. The contents of ash and damaged starch in whole wheat flour were decreased by 0.12%–0.14% and 1.0–2.1 UCDc, respectively; insoluble dietary fiber and total dietary fiber were decreased by 0.38%–0.49% and 0.13%–0.17%, respectively, while soluble dietary fiber was increased by 0.22%–0.33% with increasing debranning degree. Besides, the pasting properties of whole wheat flour were increased with increasing debranning degree, the stability time was prolonged by 0.3–0.7 min, and the degree of softening was decreased by 9–25 FU. The hardness, gumminess and chewiness of steamed bread were decreased by 732–1 114 g, 335–549, and 147–346 respectively, and the springiness and resilience were increased by 0.030–0.031, and 0.049–0.066, respectively. At the same time, the overall sensory score and L* value of steamed bread were increased, indicating that debranning treatment can significantly improve the rheological properties of whole wheat flour, and efficiently improve the quality of steamed bread

Doped holographic fermionic system

We construct a two-current model. It includes two gauge fields, which introduce the doping effect, and a neutral scalar field. And then we numerically construct an AdS black brane geometry with scalar hair. Over this background, we study the fermionic system with the pseudoscalar Yukawa coupling. Some universal properties from the pseudoscalar Yukawa coupling are revealed. In particular, as the coupling increases, there is a transfer of the spectral weight from the low energy band to the high energy band. The transfer is over low energy scales but not over all energy scales. The peculiar properties are also explored. The study shows that with the increase of the doping, the gap opens more difficult. It indicates that there is a competition between the pseudoscalar Yukawa coupling and the doping.Comment: 18 pages, 9 figure