Catálogo de publicaciones - revistas

<jats:p> <jats:italic>We propose a model for a three-terminal quantum well heat engine with heat leakage. According to the Landauer formula, the expressions for the charge current, the heat current, the power output and the efficiency are derived in the linear-response regime. The curves of the power output and the efficiency versus the positions of energy levels and the bias voltage are plotted by numerical calculation. Moreover, we obtain the maximum power output and the corresponding efficiency, and analyze the influence of the heat leakage factor, the positions of energy levels and the bias voltage on these performance parameters.</jats:italic> </jats:p>

<jats:p> <jats:italic>At low four-momentum transfer squared 0.02 &lt; −<jats:italic>t</jats:italic> &lt; 0.2 (GeV/<jats:italic>c</jats:italic>)<jats:sup>2</jats:sup>, we use the Chou–Yang model to predict the form factor of protons from proton–proton elastic scattering at center-of-mass energy <jats:inline-formula> <jats:tex-math><?CDATA $\sqrt{s}=8$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpl_36_6_061201_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> TeV. By fitting differential cross-sectional data from the TOTEM experiment to a single Gaussian, the form factor is extracted. We use this form factor to find the rms matter radius of the proton to be 0.88 fm, which is in good agreement with the experimental data and the theoretically predicted values of the rms radius.</jats:italic> </jats:p>

<jats:p> <jats:italic>The nucleonic <jats:sup>1</jats:sup> <jats:italic>S</jats:italic> <jats:sub>0</jats:sub> superfluidity is investigated by solving the gap equation for the Reid soft-core potential as the nucleon–nucleon interaction in neutron star (NS) matter which is considered to be made up of n, p, e, <jats:italic>μ</jats:italic> and condensed antikaon matter. We mainly study the influence of the soft pion-induced potential on the nucleonic <jats:sup>1</jats:sup> <jats:italic>S</jats:italic> <jats:sub>0</jats:sub> pairing gaps in the above NS matter. It is found that the intensities of the nucleonic <jats:sup>1</jats:sup> <jats:italic>S</jats:italic> <jats:sub>0</jats:sub> pairing gaps including the soft pion-induced potential are smaller than those calculated in the case of not including the soft pion-induced potential. Furthermore, the nucleonic <jats:sup>1</jats:sup> <jats:italic>S</jats:italic> <jats:sub>0</jats:sub> pairing gaps with the soft pion-induced potential fall into decline with the deepening of the optical potential of antikaons in the above NS matter, whereas they increase with the parameter <jats:italic>η</jats:italic> for the fixed optical potential of antikaons. Due to the appearance of the soft pion-induced potential, the maximum values of nucleonic <jats:sup>1</jats:sup> <jats:italic>S</jats:italic> <jats:sub>0</jats:sub> pairing gaps at parameter <jats:italic>η</jats:italic> = 0.20, 0.55 are suppressed by 1.7%–6.8% with respect to the case without soft pion-induced potential in the above NS matter.</jats:italic> </jats:p>

<jats:p> <jats:italic>Traditional “magic numbers” were once regarded as immutable throughout the nuclear chart. However, unexpected changes were found for unstable nuclei around <jats:italic>N</jats:italic> = 20. With both proton and neutron numbers around the magic number of 20, the neutron-rich <jats:sup>39</jats:sup>Cl isotope provides a good test case for the study of the quantum-state evolution across the major shell. In the present work, the negative parity states in <jats:sup>39</jats:sup>Cl are investigated through the <jats:italic>β</jats:italic> decay spectroscopy of <jats:sup>39</jats:sup>S. Newly observed <jats:italic>γ</jats:italic> transitions together with a new state are assigned into the level scheme of <jats:sup>39</jats:sup>Cl. The spin parity of 5/2<jats:sup>−</jats:sup> for the lowest negative parity state in <jats:sup>39</jats:sup>Cl is reconfirmed using the combined <jats:italic>γ</jats:italic> transition information. These systematic observations of the negative parity states in <jats:sup>39</jats:sup>Cl allow a comprehensive comparison with the theoretical descriptions. The lowest 5/2<jats:sup>−</jats:sup> state in <jats:sup>39</jats:sup>Cl remains exotic in terms of comparisons with existing theoretical calculations and with the neighboring isotopes having similar single-particle configurations. Further experimental and theoretical investigations are suggested.</jats:italic> </jats:p>

<jats:p> <jats:italic>A new observable, the angle between <jats:italic>Λ</jats:italic> and <jats:inline-formula> <jats:tex-math><?CDATA $\bar{\Lambda }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mover accent="true"> <mml:mi>Λ</mml:mi> <mml:mo stretchy="false">¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpl_36_6_062301_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> decay planes, is proposed to test the theoretical predictions on the spin correlation. With 10 billion <jats:italic>J</jats:italic>/<jats:italic>ψ</jats:italic> events collected with the BESIII detector at the BEPCII <jats:italic>e</jats:italic> <jats:sup>+</jats:sup> <jats:italic>e</jats:italic> <jats:sup>−</jats:sup> collider, the distribution of the angle could be measured to verify whether or not a correlation exists.</jats:italic> </jats:p>

<jats:p> <jats:italic>As a crucial parameter for a few-cycle laser pulse, the carrier envelope phase (CEP) substantially determines the laser waveform. We propose a method to directly describe the CEP of an isolated attosecond pulse (IAP) by the vortex-shaped momentum pattern, which is generated from the tunneling ionization of a hydrogen atom by a pair of time-delayed, oppositely and circularly polarized IAP-IR pulses. Superior to the angular streaking method that characterizes the CEP in terms of only one streak, our method describes the CEP of an IAP by the features of multiple streaks in the vortex pattern. The proposed method may open the possibility of capturing sub-cycle extreme ultraviolet dynamics.</jats:italic> </jats:p>

<jats:p> <jats:italic>We experimentally investigate the continuous-wave (cw) and acousto-optical (AO) Q-switched performance of a diode-pumped Ho:(Sc<jats:sub>0.5</jats:sub>Y<jats:sub>0.5</jats:sub>)<jats:sub>2</jats:sub>SiO<jats:sub>5</jats:sub> (Ho:SYSO) laser. A fiber-coupled laser diode at 1.91 <jats:italic>μ</jats:italic>m is employed as the pump source. The cw Ho:SYSO laser produces 13.0 W output power at 2097.9 nm and 56.0% slope efficiency with respect to the absorbed pump power. In the AO Q-switched regime, at a pulse repetition frequency of 5 kHz, the Ho:SYSO laser yields 2.1 mJ pulse energy and 21 ns pulse width, resulting in a calculated peak power of 100 kW. In addition, at the maximum output level, the beam quality factor of the Q-switched Ho:SYSO laser is measured to be about 1.6.</jats:italic> </jats:p>

<jats:p> <jats:italic>We present a planar model system of a silica covered with a monolayer of nonlinear graphene to achieve a tunable Goos–Hänchen (GH) shift in the terahertz range. It is theoretically found that the transition between a negative shift and a large positive one can be realized by altering the intensity of incident light. Moreover, by controlling the chemical potential of graphene and the incident angle of light, we can further control the tunable GH shift dynamically. Numerical simulations for GH shifts based on Gaussian waves are in good agreement with our theoretical calculations</jats:italic>.</jats:p>

<jats:p> <jats:italic>We study the negative thermal expansion (NTE) properties and effect of Na insertion on the NTE of the framework material GaFe(CN)<jats:sub>6</jats:sub> by first-principles calculations based on density functional theory within the quasi-harmonic approximation. The calculated results show that the material exhibits NTE due to the low transverse vibrational modes of the CN groups. The modes demonstrate larger negative values of the mode Grüneisen parameters. Once Na is introduced in the framework of the material, it prefers to locate at the center of the quadrates of the framework material and binds to the four N anions nearby. As a consequence, the transverse vibrational mode of the CN group is clearly hindered and the NTE of the material is weakened. Our theoretical calculations have clarified the mechanisms of NTE and the effect of the guest Na on the NTE of the framework material</jats:italic>.</jats:p>

<jats:p> <jats:italic>Structural, thermal expansion, and magnetic properties of the Dy<jats:sub>2</jats:sub>Fe<jats:sub>16</jats:sub>Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy<jats:sub>2</jats:sub>Fe<jats:sub>16</jats:sub>Cr compound has a hexagonal Th<jats:sub>2</jats:sub>Ni<jats:sub>17</jats:sub>-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy<jats:sub>2</jats:sub>Fe<jats:sub>16</jats:sub>Cr compound. The average thermal expansion coefficient is −0.794 × 10<jats:sup>−5</jats:sup>/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed</jats:italic>.</jats:p>