The nucleus^{206}Po was studied in the two proton transfer reaction^{204}Pb(^{16}O,^{14}C)^{206}Po and the lifetime of the first excited 2^{+}state was determined by utilizing the Recoil Distance Doppler Shift method. The experimental results are compared with shellmodel calculations based on different effective interactions. The calculations qualitatively reproduced the experimentally observed
In this work, we develop a deep neural network model for the reaction rate of oxidative coupling of methane from published highthroughput experimental catalysis data. A neural network is formulated so that the rate model satisfies the plug flow reactor design equation. The model is then employed to understand the variation of reactant and product composition within the reactor for the reference catalyst Mn–Na_{2}WO_{4}/SiO_{2}at different temperatures and to identify new catalysts and combinations of known catalysts that would increase yield and selectivity relative to the reference catalyst. The model revealed that methane is converted in the first half of the catalyst bed, while the second part largely consolidates the products (i.e. increases ethylene to ethane ratio). A screening study of
 Award ID(s):
 2045550
 NSFPAR ID:
 10385832
 Publisher / Repository:
 IOP Publishing
 Date Published:
 Journal Name:
 Journal of Physics: Energy
 Volume:
 5
 Issue:
 1
 ISSN:
 25157655
 Page Range / eLocation ID:
 Article No. 014009
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
More Like this

Abstract value, suggesting that the $B(E2;{2}_{1}^{+}\to {0}_{1}^{+})$ state of^{206}Po exhibits a collective nature. However, the employed effective interactions revealed some limitations, particularly in their description of the ${2}_{1}^{+}$ states. These results emphasize the importance of understanding the properties of lowlying states, especially their evolution from singleparticle dynamics to collective modes, in evaluating various effective nuclear interactions. ${4}_{1,2}^{+}$ 
Abstract We measure the thermal electron energization in 1D and 2D particleincell simulations of quasiperpendicular, lowbeta (
β _{p}= 0.25) collisionless ion–electron shocks with mass ratiom _{i}/m _{e}= 200, fast Mach number –4, and upstream magnetic field angle ${\mathcal{M}}_{\mathrm{ms}}=1$θ _{Bn}= 55°–85° from the shock normal . It is known that shock electron heating is described by an ambipolar, $\stackrel{\u02c6}{\mathit{n}}$ parallel electric potential jump, ΔB ϕ _{∥}, that scales roughly linearly with the electron temperature jump. Our simulations have –0.2 in units of the preshock ions’ bulk kinetic energy, in agreement with prior measurements and simulations. Different ways to measure $\mathrm{\Delta}{\varphi}_{\parallel}/(0.5{m}_{\mathrm{i}}{{u}_{\mathrm{sh}}}^{2})\sim 0.1$ϕ _{∥}, including the use of de Hoffmann–Teller frame fields, agree to tensofpercent accuracy. Neglecting offdiagonal electron pressure tensor terms can lead to a systematic underestimate ofϕ _{∥}in our lowβ _{p}shocks. We further focus on twoθ _{Bn}= 65° shocks: a ( ${\mathcal{M}}_{\mathrm{s}}\phantom{\rule{0.25em}{0ex}}=\phantom{\rule{0.25em}{0ex}}4$ ) case with a long, 30 ${\mathcal{M}}_{\mathrm{A}}\phantom{\rule{0.25em}{0ex}}=\phantom{\rule{0.25em}{0ex}}1.8$d _{i}precursor of whistler waves along , and a $\stackrel{\u02c6}{\mathit{n}}$ ( ${\mathcal{M}}_{\mathrm{s}}\phantom{\rule{0.25em}{0ex}}=\phantom{\rule{0.25em}{0ex}}7$ ) case with a shorter, 5 ${\mathcal{M}}_{\mathrm{A}}\phantom{\rule{0.25em}{0ex}}=\phantom{\rule{0.25em}{0ex}}3.2$d _{i}precursor of whistlers oblique to both and $\stackrel{\u02c6}{\mathit{n}}$ ;B d _{i}is the ion skin depth. Within the precursors,ϕ _{∥}has a secular rise toward the shock along multiple whistler wavelengths and also has localized spikes within magnetic troughs. In a 1D simulation of the , ${\mathcal{M}}_{\mathrm{s}}\phantom{\rule{0.25em}{0ex}}=\phantom{\rule{0.25em}{0ex}}4$θ _{Bn}= 65° case,ϕ _{∥}shows a weak dependence on the electron plasmatocyclotron frequency ratioω _{pe}/Ω_{ce}, andϕ _{∥}decreases by a factor of 2 asm _{i}/m _{e}is raised to the true proton–electron value of 1836. 
Abstract We present the directimaging discovery of a giant planet orbiting the young star AF Lep, a 1.2
M _{⊙}member of the 24 ± 3 Myrβ Pic moving group. AF Lep was observed as part of our ongoing highcontrast imaging program targeting stars with astrometric accelerations between Hipparcos and Gaia that indicate the presence of substellar companions. Keck/NIRC2 observations in with the vector vortex coronagraph reveal a point source, AF Lep b, at ≈340 mas, which exhibits orbital motion at the 6 $L\prime $σ level over the course of 13 months. A joint orbit fit yields precise constraints on the planet’s dynamical mass of ${3.2}_{0.6}^{+0.7}$M _{Jup}, semimajor axis of au, and eccentricity of ${8.4}_{1.3}^{+1.1}$ . AF Lep hosts a debris disk located at ∼50 au, but it is unlikely to be sculpted by AF Lep b, implying there may be additional planets in the system at wider separations. The stellar inclination ( ${0.24}_{0.15}^{+0.27}$i _{*}= ) and orbital inclination ( ${54}_{9}^{+11}\xb0$i _{o}= ) are in good agreement, which is consistent with the system having spin–orbit alignment. AF Lep b is the lowestmass imaged planet with a dynamical mass measurement and highlights the promise of using astrometric accelerations as a tool to find and characterize longperiod planets. ${50}_{12}^{+9}\xb0$ 
Abstract The interplay between charge transfer and electronic disorder in transitionmetal dichalcogenide multilayers gives rise to superconductive coupling driven by proximity enhancement, tunneling and superconducting fluctuations, of a yet unwieldy variety. Artificial spacer layers introduced with atomic precision change the density of states by charge transfer. Here, we tune the superconductive coupling between
monolayers from proximityenhanced to tunnelingdominated. We correlate normal and superconducting properties in $\text{NbS}{\text{e}}_{\text{2}}$ tailored multilayers with varying SnSe layer thickness ( ${\left[{\left(\text{SnSe}\right)}_{1+\delta}\right]}_{m}{\left[\text{NbS}{\text{e}}_{\text{2}}\right]}_{1}$ ). From highfield magnetotransport the critical fields yield Ginzburg–Landau coherence lengths with an increase of $m=115$ crossplane ( $140\mathrm{\%}$ ), trending towards twodimensional superconductivity for $m=19$ . We show crossovers between three regimes: metallic with proximityenhanced coupling ( $m>9$ ), disorderedmetallic with intermediate coupling ( $m=14$ ) and insulating with Josephson tunneling ( $m=59$ ). Our results demonstrate that stacking metal mono and dichalcogenides allows to convert a metal/superconductor into an insulator/superconductor system, prospecting the control of twodimensional superconductivity in embedded layers. $m>9$ 
Abstract Polyatomic molecules have been identified as sensitive probes of chargeparity violating and parity violating physics beyond the Standard Model (BSM). For example, many linear triatomic molecules are both lasercoolable and have parity doublets in the ground electronic
state arising from the bending vibration, both features that can greatly aid BSM searches. Understanding the $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ state is a crucial prerequisite to precision measurements with linear polyatomic molecules. Here, we characterize the fundamental bending vibration of $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ YbOH using highresolution optical spectroscopy on the nominally forbidden ${}^{174}$ $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ transition at 588 nm. We assign 39 transitions originating from the lowest rotational levels of the $\to \tilde{A}{}^{2}{\mathrm{\Pi}}_{1/2}(000)$ state, and accurately model the state’s structure with an effective Hamiltonian using bestfit parameters. Additionally, we perform Stark and Zeeman spectroscopy on the $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ state and fit the moleculeframe dipole moment to $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ ${D}_{\mathrm{m}\mathrm{o}\mathrm{l}}=2.16(1)$D and the effective electrong factor to . Further, we use an empirical model to explain observed anomalous line intensities in terms of interference from spin–orbit and vibronic perturbations in the excited ${g}_{S}=2.07(2)$ state. Our work is an essential step toward searches for BSM physics in YbOH and other linear polyatomic molecules. $\tilde{A}{}^{2}{\mathrm{\Pi}}_{1/2}(000)$