Triangle mechanism in the decay process B0→J/ψK0f0(980)(a0(980))B_0 \to J/\psi K^0 f_0(980)(a_0(980))

The role of the triangle mechanism in the decay process $B_0\to J/\psi K^0f_0 \to J/\psi K^0\pi^+\pi^-$ and $B_0\to J\psi K^0a_0\to J/\psi K^0 \pi^0\eta$ is probed. In these process, the triangle singularity appears from the decay of $B^0$ into $J/\psi\phi K^0$ then $\phi$ decays into $K^0\bar{K^0}$ and $K^0\bar{K^0}$ merged into $f_0$ or $a_0$ which finally decay into $\pi^+\pi^-$ and $\pi^0\eta$ respectively. We find that this mechanism leads to a triangle singularity around $M_{\rm inv}(K^0f_0(a_0))\approx1520\ {\rm MeV}$, and gives sizable branching fractions ${\rm{Br}}(B_0\to J/\psi K^0f_0\to J/\psi K^0\pi^+\pi^-)=1.38\times10^{-6}$ and ${\rm{Br}}(B_0\to J/\psi K^0a_0\to J/\psi K^0\pi^0\eta)=2.56\times10^{-7}$. This potential investigation can help us obtain the information of the scalar meson $f_0(980)$ or $a_0(980)$.Comment: 8 pages, 6 figure

Pole determination of X(3960)X(3960) and X0(4140)X_0(4140) in decay B+→K+Ds+Ds−B^+\to K^+D_s^+D_s^-

Two near-threshold peaking structures with spin-parities $J^{PC}=0^{++}$ were recently discovered by the LHCb Collaboration in the $D_s^+D_s^-$ invariant mass distribution of the decay process $B^+\to D_s^+D_s^-K^+$. In our study, we employed a coupled-channel model to fit the experimental results published by the LHCb collaboration, simultaneously fitting the model to the invariant mass distributions of $M_{D_s^+D_s^-}$, $M_{D_s^+K^+}$, and $M_{D_s^-K^+}$. We utilized a coupled-channel model to search for the poles of $X(3960)$ and $X_0(4140)$. The determination of the poles is meaningful in itself, and it also lays an foundation for the future research on $X(3960)$ and $X_0(4140)$. Upon turning off the coupled-channel and performing another fit, we observed a change in the fitting quality, the effect was almost entirely due to the peak of $X(3960)$, so we suggest that $X(3960)$ may not be a kinematic effect.Comment: 6 pages, 7 figure

Modélisation Stochastique de Réseaux Radio

La modélisation stochastique permet à de nombreux travaux d'étudier les réseaux fixes et d'évaluer leurs performances. Aujourd'hui la modélisation et l'évaluation de performance est souvent étendue aux problématiques des réseaux radio. Les variations spatiales et temporelles du médium à partager opposent ces réseaux aux réseaux filaires de part la disponibilité à l'instant $t$ d'une ressource. Cette caractérisation suffit à comprendre qu'un modèle issu d'un environnement fixe et étendu aux réseaux radio ne peut être satisfaisant. La plupart des propositions existantes font l'hypothèse que les canaux de transmission sont parfaits, l'aspect des caractéristiques radios sont rarement pris en compte. L'objectif de ce travail est de proposer une méthode pour intégrer la caractérisation de l'environnement radio dans un modèle analytique. Avec ce modèle, nous sommes en mesure d'évaluer les performances (taux d'utilisation bande passante en fonction du nombre de machine, probabilité de retransmission, etc.) d'un réseau 802.11b déployé en indoor suivant une couverture radio (issue de l'outil de planification WILDE, Wireless Lan Designing Tool,C'est un outil de propagation indoor pour réseau 802.11b, développé au laboratoire CITI). Dans ce mémoire nous proposons, en premier lieu, une analyse sur la carte de couverture radio. Elle nous permet d'exprimer certains paramètres stochastiques en fonction des caractéristiques radios. Puis dans un deuxième temps, nous intégrons ces paramètres dans un modèle analytique bien connue dans le domaine de l'évaluation de performances des réseaux radio. Nous illustrons aussi les problématiques d'une modélisation d'un réseau radio dans un environnement réel

Investigation on Combination of Airflow Disturbance and Sprinkler Irrigation for Horticultural Crop Frost Protection

Frost tends to be detrimental to the growth and development of horticultural crops, leading to yield or quality reduction with sizable economic losses. Therefore, it is very important to develop frost protection technology for horticultural crops. In this study, the development of frost protection technology is reviewed, and the research of mechanized frost protection technology in recent years is analyzed. In view of the poor frost protection effect of some single mechanized frost protection technology, the combination frost protection technology is put forward. The combination frost protection technology with airflow disturbance and sprinkler irrigation is discussed and analyzed

Catalytic trajectory of a dimeric nonribosomal peptide synthetase subunit with an inserted epimerase domain.

Nonribosomal peptide synthetases (NRPSs) are modular assembly-line megaenzymes that synthesize diverse metabolites with wide-ranging biological activities. The structural dynamics of synthetic elongation has remained unclear. Here, we present cryo-EM structures of PchE, an NRPS elongation module, in distinct conformations. The domain organization reveals a unique "H"-shaped head-to-tail dimeric architecture. The capture of both aryl and peptidyl carrier protein-tethered substrates and intermediates inside the heterocyclization domain and L-cysteinyl adenylate in the adenylation domain illustrates the catalytic and recognition residues. The multilevel structural transitions guided by the adenylation C-terminal subdomain in combination with the inserted epimerase and the conformational changes of the heterocyclization tunnel are controlled by two residues. Moreover, we visualized the direct structural dynamics of the full catalytic cycle from thiolation to epimerization. This study establishes the catalytic trajectory of PchE and sheds light on the rational re-engineering of domain-inserted dimeric NRPSs for the production of novel pharmaceutical agents

Error-Mitigated Quantum Simulation of Interacting Fermions with Trapped Ions

Quantum error mitigation has been extensively explored to increase the accuracy of the quantum circuits in noisy-intermediate-scale-quantum (NISQ) computation, where quantum error correction requiring additional quantum resources is not adopted. Among various error-mitigation schemes, probabilistic error cancellation (PEC) has been proposed as a general and systematic protocol that can be applied to numerous hardware platforms and quantum algorithms. However, PEC has only been tested in two-qubit systems and a superconducting multi-qubit system by learning a sparse error model. Here, we benchmark PEC using up to four trapped-ion qubits. For the benchmark, we simulate the dynamics of interacting fermions with or without spins by applying multiple Trotter steps. By tomographically reconstructing the error model and incorporating other mitigation methods such as positive probability and symmetry constraints, we are able to increase the fidelity of simulation and faithfully observe the dynamics of the Fermi-Hubbard model, including the different behavior of charge and spin of fermions. Our demonstrations can be an essential step for further extending systematic error-mitigation schemes toward practical quantum advantages.Comment: 15 pages, 11 figure

IRE1α promotes cell apoptosis and an inflammatory response in endoplasmic reticulum stress-induced rheumatoid arthritis fibroblast-like synovial cells by enhancing autophagy

Endoplasmic reticulum (ER) stress can induce autophagy via the unfolded protein response (UPR), and autophagy can regulate the activation of inflammasomes. Inositol-requiring enzyme 1α (IRE1α) is a transducer of the UPR in cells with ER stress. Here, we investigated the role of IRE1α and its impact on ER stress in rheumatoid arthritis fibroblast-like synovial cells (RA-FLSs). RA-FLSs were isolated from rheumatoid arthritis (RA) patients and stimulated with thapsigargin (TG) to produce ER stress cells. ER stress-, autophagy and the expression of apoptosis-associated factors were investigated by western blotting and the qRT-PCR. Cellular ROS levels were assessed by flow cytometry. ELISAs were performed to determine the concentrations of inflammatory mediators. TG treatment promoted IRE1α, GRP78, CHOP, and ATP6 mRNA and protein expression. ROS generation was increased in TG-induced RA-FLSs; additionally, TG was found to induce cell inflammation by upregulating the expression of inflammasome markers and the concentrations of inflammatory mediators. The levels of autophagy markers, apoptosis-associated proteins, and mRNA were increased in TG-stimulated RA-FLSs. However, transfection with si-IRE1α suppressed TG-induced increases in ROS generation, inflammation levels, cell apoptosis, and autophagy in RA-FLSs. Treatment with the autophagy activator RAPA attenuated the protective effects of IRE1α silencing on TG-induced RA-FLS apoptosis and inflammatory damage. Our findings showed that in RA-FLSs, IRE1α silencing alleviated ER stress-induced inflammation and apoptosis caused by autophagy

Scalable and Programmable Phononic Network with Trapped Ions

Controllable bosonic systems can provide post-classical computational power with sub-universal quantum computational capability. A network that consists of a number of bosons evolving through beam-splitters and phase-shifters between different modes, has been proposed and applied to demonstrate quantum advantages. While the network has been implemented mostly in optical systems with photons, recently alternative realizations have been explored, where major limitations in photonic systems such as photon loss, and probabilistic manipulation can be addressed. Phonons, the quantized excitations of vibrational modes, of trapped ions can be a promising candidate to realize the bosonic network. Here, we experimentally demonstrate a minimal-loss phononic network that can be programmed and in which any phononic states are deterministically prepared and detected. We realize the network with up to four collective-vibrational modes, which can be straightforwardly extended to reveal quantum advantage. We benchmark the performance of the network with an exemplary algorithm of tomography for arbitrary multi-mode states with a fixed total phonon number. We obtain reconstruction fidelities of 94.5 $\pm$ 1.95 % and 93.4 $\pm$ 3.15 % for single-phonon and two-phonon states, respectively. Our experiment demonstrates a clear and novel pathway to scale up a phononic network for various quantum information processing beyond the limitations of classical and other quantum systems