Creación de personaje en la técnica clown de la puesta en escena "Los merolicos"

La creación de personaje en la técnica clown para la puesta en escena “Los merolicos

Absolute frequency measurements with a robust, transportable ^{40}Ca^{+} optical clock

We constructed a transportable 40Ca+ optical clock (with an estimated minimum systematic shift uncertainty of 1.3*10^(-17) and a stability of 5*10^(-15)/sqrt{tau} ) that can operate outside the laboratory. We transported it from the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan to the National Institute of Metrology, Beijing. The absolute frequency of the 729 nm clock transition was measured for up to 35 days by tracing its frequency to the second of International System of Units. Some improvements were implemented in the measurement process, such as the increased effective up-time of 91.3 % of the 40Ca+ optical clock over a 35-day-period, the reduced statistical uncertainty of the comparison between the optical clock and hydrogen maser, and the use of longer measurement times to reduce the uncertainty of the frequency traceability link. The absolute frequency measurement of the 40Ca+ optical clock yielded a value of 411042129776400.26 (13) Hz with an uncertainty of 3.2*10^(-16), which is reduced by a factor of 1.7 compared with our previous results. As a result of the increase in the operating rate of the optical clock, the accuracy of 35 days of absolute frequency measurement can be comparable to the best results of different institutions in the world based on different optical frequency measurements.Comment: 15 pages, 5 figure

A systematic review of factors influencing signage salience in indoor environments

Wayfinding signage is an intermediary public facility that coordinates the relationship between space and people, and it is crucial to help people find their way in complex indoor environments. In people’s cognitive behaviour towards wayfinding signs, the visual salience of the signs is the prerequisite and key to ensuring their effective operation. This paper aims to review published research articles on the effect of indoor environments on the saliency of wayfinding signs. The literature review was conducted by PICO methodology to formulate the research question and develop search strategies. Relevant research articles were identified by systematically searching electronic databases, including Web of Science, ScienceDirect, ProQuest, and EBSCO. This paper summarises two categories of factors influencing signage salience: (1) floor plan factors and (2) environmental factors. This study examined and condensed the attributes of wayfinding signage and their impact on how pedestrians perceive visuals while navigating. Exploring the elements that influence the visual prominence of indoor signs enhances our comprehension of how pedestrians engage with visually guided information indoors. Furthermore, this offers a theoretical foundation for the realm of indoor wayfinding

Cassava genome from a wild ancestor to cultivated varieties

Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology

Insights on the Formation Mechanism of Ultra-Low Friction of Phenolic Resin Graphite at High Temperature

In the present paper, the influences of high temperature on the tribological properties of phenolic resin graphite (PRG) sliding against tungsten carbide-nickel (WC-Ni) alloy in ambient air were investigated systematically. Results demonstrated that the antifriction behaviors of PRG was sensitive to high temperature and PRG exhibits ultra-low coefficient of friction (CoF) of about 0.01–0.015. The low CoF is attributed to the formation of graphite tribofilms, which shows different formation processes on the contact interface at different temperatures (room temperature, 200, 300 and 400 °C). These findings provide insight into the formation mechanism of graphite tribofilms, and provide an important basis for improving the tribological properties of graphite-based friction materials and manufacturing new graphite for seal applications

Temperature dependent photoexcited carrier dynamics in multiferroic BiFeO3 film: a hidden phase transition

The ultrafast carrier dynamics of the multiferroic BiFeO3 film in a broad temperature range is investigated using optical pump-probe spectroscopy. The photoexcited electrons release their energy with optical phonons emission through electron-phonon coupling in about 1 ps. The following intermediate process is identified as dynamical spin-lattice coupling in several picoseconds. Furthermore, the peak values of the optical reflectivity and the time constants of carrier relaxation channels show significant changes while the temperature varies from 137.5 K to around 195 K, this aligns with the previously reported hidden phase transition. Our study demonstrates that ultrafast spectroscopy is a sensitive method to look into the dynamical interactions among the on-site high-energy electrons accumulated in the p conduction band of Bi, coherent optical phonon, as well as the spin degree of freedom. These features play crucial roles in the characterization of phase transitions

Dynamic analysis on fluid-structure interaction of an elastically mounted square cylinder at low Reynolds numbers

Fluid-structure interaction of an elastically mounted rigid square cylinder of low non-dimensional mass immersed in fluid flow is investigated numerically in the Reynolds numbers range of 60≤Re≤250. The square cylinder is allowed to freely vibrate only in the transverse direction perpendicular to the incoming flow. The two-dimensional incompressible Reynolds-averaged Navier-Stokes equations are solved by the finite volume method for the fluid flow. The equation of motion is solved for the vibration of the square cylinder. The results show that abrupt both the frequency and amplitude ratios curves experience sudden change at Re=90 and 168, which marks the onset of the lock-in and galloping regime, respectively. Thus, four regimes can be divided in the present study and which are the initial regime, the lock-in regime, the lower branch and galloping regime. A local peak value is observed in the force coefficients curve and the maximum value is reached at Re=231. It is found that the peak oscillating amplitude of the lock-in regime is reached at 0.22D and the width of lock-in region with sharp corner is very narrow. In the galloping regime, the peak amplitude of the oscillating square cylinder is close to 0.70D at Re=231. Typical 2S vortex structure is observed in the initial regime, the lock-in regime, and the lower branch. While in the galloping regime, 2P, 2P+2S and more complicated vortex patterns are observed as Re increases