Lower Bounds of Concurrence for Multipartite States

We study the entanglement of multipartite quantum states. Some lower bounds of the multipartite concurrence are reviewed. We further present more effective lower bounds for detecting and qualifying entanglement, by establishing functional relations between the concurrence and the generalized partial transpositions of the multipartite systems.Comment: 13 page

Research on web security test based on kali Linux

web security is mainly divided into server security and client security, in B/S architecture occupies half of the Internet service today, the security level of the web level determines the user and enterprise information security protection level. The purpose of penetration testing is to help enterprises and companies fi nd possible vulnerabilities, and carry out threat analysis of vulnerabilities, and provide vulnerabilities recurrence and repair suggestions. kali Linux, which redevelops BackTrack based on the Debian development standard, is a specialized penetration testing and security audit platform pre-installed with a wealth of penetration testing tools. Using kali Linux during penetration testing will greatly reduce the time and cost of testing, and the use of tools and scripts will make the penetration testing work more eff ective and eff ective. In this paper, the author will develop a simulation of the penetration test of simulated network services which based on kali Linux security tools and python scripts, and make principle analysis and repair suggestions on the existing vulnerabilities

External characteristic analysis and stator parameter optimization for a torque converter

The performance of a flattened hydraulic torque converter is optimized with orthogonal experiment and response surface method, considering parameters of its stator blade, defined with nonuniform rotational B-splines. The optimization model, with maximum of the stalling torque ratio as an objective, is determined through an external characteristic statistical analysis under the new European Driving Cycle condition. The optimization results show that the stall torque ratio is increased by 10.83%, while the highest efficiency is above 84%

Excitation functions of parameters extracted from three-source (net-)proton rapidity distributions in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

Experimental results of the rapidity spectra of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a three-source distribution. The values of the distribution width $\sigma_C$ and contribution ratio (relative contribution) $k_C$ of the central rapidity region, and the distribution width $\sigma_F$ and rapidity shift $\Delta y$ of the forward/backward rapidity regions, are then obtained. The excitation function of $\sigma_C$ increases generally with increase of the center-of-mass energy per nucleon pair $\sqrt{s_{NN}}$. The excitation function of $\sigma_F$ shows a saturation at $\sqrt{s_{NN}}=8.8$ GeV. The excitation function of $k_C$ shows a minimum at $\sqrt{s_{NN}}=8.8$ GeV and a saturation at $\sqrt{s_{NN}}\approx 17$ GeV. The excitation function of $\Delta y$ increase monotonously with $\ln \sqrt{s_{NN}}$ in the considered energy range.Comment: 19 pages, 8 figures, The European Physical Journal A, accepte

Acute aerobic exercise alters executive control network in preadolescent children

The present study aimed to investigate the effect of acute aerobic exercise on executive function (EF) and executive control network (ECN) in preadolescent children, and further explored the neural basis of acute aerobic exercise on EF in these children. We used a within-subjects design with a counterbalanced order. Nine healthy, right-handed children were scanned with resting-state functional magnetic resonance imaging and performed an EF task both in baseline session and exercise session. The exercise session was consisted of 30 minutes of aerobic exercise on a bicycle ergometer at 60% of their estimated maximum heart rate. Compared with the baseline session, acute aerobic exercise benefitted performance in the EF task, increased the functional connectivity between right dorsolateral prefrontal and left cerebellum, further, the increment of functional connectivity was negatively correlated with the EF' s behavioral performance change. These findings suggest that acute aerobic exercise enhances children's EF, and the neural basis may be related to functional connectivity changes in the ECN elicited by acute aerobic exercise.El objetivo de esta investigación es estudiar la influencia del ejercicio aeróbico agudo en la función ejecutiva (EF) y la red de control ejecutiva (REC) en niños preadolescentes, además explorar la base neutral de estos ejercicios aeróbicos en los niños. Hemos utilizado un diseño de orden equilibrado. Nueve niños diestros saludables fueron escaneados con resonancia magnética funcional y se llevaron a cabo tareas de EF, sesiones de ejercicio y sesiones de medición basal. Comparado con las sesiones de base, la sesión de ejercicio consistió en 30 minutos de ejercicios aeróbicos en bicicleta ergométrica al 60% del ritmo cardiaco máximo estimado. Comparado con la sesión basal, el ejercicio aeróbico agudo benefició el desempeño en la tarea EF, aumentó la conectividad funcional entre el prefrontal dorsolateral derecho y el cerebelo izquierdo, además, el incremento de conectividad funcional se correlacionó negativamente con el cambio en el comportamiento del EF. Los resultados de estos estudios demuestran que el ejercicio aeróbico agudo refuerza, y puede provocar ciertos cambios