Catálogo de publicaciones - revistas

<jats:p>Porphine has a great potential application in molecular electronic devices. In this work, based on the density functional theory (DFT) and combining with nonequilibrium Green’s function (NEGF), we study the transport properties of the molecular devices constructed by the covalent homocoupling of porphine molecules conjunction with zigzag graphene nanoribbons electrodes. We find that different couple phases bring remarkable differences in the transport properties. Different coupling phases have different application prospects. We analyze and discuss the differences in transport properties through the molecular energy spectrum, electrostatic difference potential, local density of states (LDOS), and transmission pathway. The results are of great significance for the design of porphine molecular devices in the future.</jats:p>

<jats:p>Based on a femtosecond laser plasma-induced hard x-ray source with a high laser pulse energy (&gt; 100 mJ) at 10 Hz repetition rate, we present a time-resolved x-ray diffraction system on an ultrafast time scale. The laser intensity is at relativistic regime (2 × 10<jats:sup>19</jats:sup> W/cm<jats:sup>2</jats:sup>), which is essential for effectively generating <jats:italic>K<jats:sub>α</jats:sub> </jats:italic> source in high-<jats:italic>Z</jats:italic> metal material. The produced copper <jats:italic>K<jats:sub>α</jats:sub> </jats:italic> radiation yield reaches to 2.5 × 10<jats:sup>8</jats:sup> photons/sr/shot. The multilayer mirrors are optimized for monochromatizating and two-dimensional beam shaping of <jats:italic>K<jats:sub>α</jats:sub> </jats:italic> emission. Our experiment exhibits its ability of monitoring the transient structural changes in a thin film SrCoO<jats:sub>2.5</jats:sub> crystal. It is demonstrated that this facility is a powerful tool to perform dynamic studies on samples and adaptable to the specific needs for different particular applications with high flexibility.</jats:p>

<jats:p>Artificial stock market simulation based on agent is an important means to study financial market. Based on the assumption that the investors are composed of a main fund, small trend and contrarian investors characterized by four parameters, we simulate and research a kind of financial phenomenon with the characteristics of pyramid schemes. Our simulation results and theoretical analysis reveal the relationships between the rate of return of the main fund and the proportion of the trend investors in all small investors, the small investors’ parameters of taking profit and stopping loss, the order size of the main fund and the strategies adopted by the main fund. Our work is helpful to explain the financial phenomenon with the characteristics of pyramid schemes in financial markets, design trading rules for regulators and develop trading strategies for investors.</jats:p>

<jats:p>Campus security has aroused many concerns from the whole society. Stampede is one of the most frequent and influential accidents in campus. Studies on pedestrian dynamics especially focusing on students are essential for campus security, which are helpful to improve facility design and emergency evacuation strategy. In this paper, primary and middle school students were recruited to participate in the single-file experiments. The microscopic movement characteristics, including walking speed, headway, gait characteristics (step length, step frequency and swaying amplitude) and their relations were investigated. Age and gender differences in the headway-speed diagram and space requirements were analyzed by statistical tests. The results indicated that the impacts of age and gender were significant. There were three stages for the influence of gender on the headway-speed diagram for both age groups. The impacts on students’ space requirements were consistent for different age and gender groups. But the impacts of age and gender on free-flow speed were affected by each other. Due to the connection of walking speed and gait characteristics, the comparisons of gait characteristics between different ages and genders were performed to understand the corresponding differences in speed more deeply. The results showed that differences in step length and swaying amplitude between males and females were significant for both age groups. The effect of gender on step frequency was significant for primary students. But for middle school students, whether gender had significant impact on step frequency was not clear here because of the large <jats:italic>P</jats:italic>-value. Besides, the influence of age on gait characteristics changed with gender.</jats:p>

<jats:p>Despite the growing interest in macroscopic epidemiological models to deal with threats posed by pandemics such as COVID-19, little has been done regarding the assessment of disease spread in day-to-day life, especially within buildings such as supermarkets where people must obtain necessities at the risk of exposure to disease. Here, we propose an integrated customer shopping simulator including both shopper movement and choice behavior, using a force-based and discrete choice model, respectively. By a simple extension to the force-based model, we implement the following preventive measures currently taken by supermarkets; social distancing and one-way systems, and different customer habits, assessing them based on the average individual disease exposure and the time taken to complete shopping (shopping efficiency). Results show that maintaining social distance is an effective way to reduce exposure, but at the cost of shopping efficiency. We find that the one-way system is the optimal strategy for reducing exposure while minimizing the impact on shopping efficiency. Customers should also visit supermarkets less frequently, but buy more when they do, if they wish to minimize their exposure. We hope that this work demonstrates the potential of pedestrian dynamics simulations in assessing preventative measures during pandemics, particularly if it is validated using empirical data.</jats:p>

<jats:p>We would like to acknowledge the misprinted terms in our published paper “Simultaneous effects of magnetic field and space porosity on compressible Maxwell fluid transport induced by a surface acoustic wave in a microchannel” [<jats:italic>Chin. Phys. B</jats:italic> <jats:bold>22</jats:bold> 124702 (2013)]. Since only two misprints exist and the main results of the published paper are correct, we present the correct equations in this erratum.</jats:p>

<jats:p>Equations (8) and (9) in the original paper [<jats:italic>Chin. Phys. B</jats:italic> <jats:bold>30</jats:bold> 036301 (2021)] are corrected.</jats:p>