What Made Me the Teacher I Am Today? A Reflection by Selected Leonore Annenberg-Woodrow Wilson Teaching Fellows

The report offers a series of short essays from 18 teachers, each reflecting on what inspired and guided them into the teaching profession. Some of the highlights include:"I've come to realize that my learning process in the classroom actually feels a whole lot like the science I practiced at the bench: engineering experimental procedures, collecting and analyzing data, and formulating questions about next steps. It turns out that my scientific worldview can really improve learning outcomes for my students," said Kristin Milks, a biology and earth science teacher in Bloomington, IN, who enrolled in a teacher preparation program shortly after completing her Ph.D. in biochemistry."What transforms someone from being a good teacher to being a great teacher is the passion to make connections with students, to constantly evaluate and adjust their practice to do what is in the students' best interest," said Catherine Ann Haney, a Virginia Spanish teacher who has recently been teaching in Santiago, Chile."Enrolling in a teacher education program, instead of starting my career as a teacher first and then obtaining my master's degree after, meant I had a cohort of other soon-to-be teachers to learn with as we persevered through a very rigorous and demanding year," said Jeremy Cress, a math teacher in Philadelphia."I realized that being a good math teacher does not mean explaining clearly, making kids like me, or making math fun. Rather, it means giving students the opportunity to solve problems by themselves from start to finish, to struggle and persevere, and to learn from each other's particular strengths," said Brittany Leknes, a math teacher from Sunnyvale, CA."Together my students and I co-create their identities, their sense of themselves, and their understanding of their place in society. Because I believe wholly in my students' own power, I teach to disrupt school cultures that suggest that students need to be anything less than their whole selves," said Kayla Vinson, who taught social students in the Harlem Children's Zone.Created in 2007, the Leonore Annenberg-Woodrow Wilson Teaching Fellowship was designed to serve as the equivalent of a national "Rhodes Scholarship" for teaching. Working with Stanford University, the University of Pennsylvania, the University of Virginia, and the University of Washington, the Woodrow Wilson Foundation provided $30,000 stipends for exceptionally able candidates to complete a yearlong master's degree program. In exchange, the teacher candidates agreed to teach for three years in high-need secondary schools across the country. The Leonore Annenberg Teaching Fellowship was funded through grants from the Annenberg Foundation and Carnegie Corporation of New York. It served as the basis for the Woodrow Wilson Foundation's successful Teaching Fellowship program, which now operates in five states (Georgia, Indiana, Michigan, New Jersey, and Ohio), operating in partnership with 28 universities. Woodrow Wilson Teaching Fellows complete a rigorous yearlong master's degree program, coupled with a robust yearlong clinical experience. Once they earn their degrees, Woodrow Wilson Teaching Fellows teach in high-need STEM classrooms, while receiving three years of coaching and mentoring

Correlation between structure and electrical transport in ion-irradiated graphene grown on Cu foils

Graphene grown by chemical vapor deposition and supported on SiO2 and sapphire substrates was studied following controlled introduction of defects induced by 35 keV carbon ion irradiation. Changes in Raman spectra following fluences ranging from 10^12 cm^-2 to 10^15 cm^-2 indicate that the structure of graphene evolves from a highly ordered layer, to a patchwork of disordered domains, to an essentially amorphous film. These structural changes result in a dramatic decrease in the Hall mobility by orders of magnitude while, remarkably, the Hall concentration remains almost unchanged, suggesting that the Fermi level is pinned at a hole concentration near 1x10^13 cm^-2. A model for scattering by resonant scatterers is in good agreement with mobility measurements up to an ion fluence of 1x10^14 cm^-2

Nitrogen-Doped Graphene and Twisted Bilayer Graphene <i>via</i> Hyperthermal Ion Implantation with Depth Control

We investigate hyperthermal ion implantation (HyTII) as a means for substitutionally doping layered materials such as graphene. In particular, this systematic study characterizes the efficacy of substitutional N-doping of graphene using HyTII over an N⁺ energy range of 25–100 eV. Scanning tunneling microscopy results establish the incorporation of N substituents into the graphene lattice during HyTII processing. We illustrate the differences in evolution of the characteristic Raman peaks following incremental doses of N⁺. We use the ratios of the integrated D and D′ peaks, <i>I</i>(D)/<i>I</i>(D′) to assess the N⁺ energy-dependent doping efficacy, which shows a strong correlation with previously reported molecular dynamics (MD) simulation results and a peak doping efficiency regime ranging between approximately 30 and 50 eV. We also demonstrate the inherent monolayer depth control of the HyTII process, thereby establishing a unique advantage over other less-specific methods for doping. We achieve this by implementing twisted bilayer graphene (TBG), with one layer of isotopically enriched ¹³C and one layer of natural ¹²C graphene, and modify only the top layer of the TBG sample. By assessing the effects of N-HyTII processing, we uncover dose-dependent shifts in the transfer characteristics consistent with electron doping and we find dose-dependent electronic localization that manifests in low-temperature magnetotransport measurements

Acoustic cavities in 2D heterostructures

Two-dimensional (2D) materials offer unique opportunities in engineering the ultrafast spatiotemporal response of composite nanomechanical structures. In this work, we report on high frequency, high quality factor (Q) 2D acoustic cavities operating in the 50–600 GHz frequency (f) range with f × Q up to 1 × 10(14). Monolayer steps and material interfaces expand cavity functionality, as demonstrated by building adjacent cavities that are isolated or strongly-coupled, as well as a frequency comb generator in MoS(2)/h-BN systems. Energy dissipation measurements in 2D cavities are compared with attenuation derived from phonon-phonon scattering rates calculated using a fully microscopic ab initio approach. Phonon lifetime calculations extended to low frequencies (<1 THz) and combined with sound propagation analysis in ultrathin plates provide a framework for designing acoustic cavities that approach their fundamental performance limit. These results provide a pathway for developing platforms employing phonon-based signal processing and for exploring the quantum nature of phonons

Looking at the distant universe with the MeerKAT array: discovery of a luminous OH megamaser at z > 0.5

In the local universe, OH megamasers (OHMs) are detected almost exclusively in infrared-luminous galaxies, with a prevalence that increases with IR luminosity, suggesting that they trace gas-rich galaxy mergers. Given the proximity of the rest frequencies of OH and the hyperfine transition of neutral atomic hydrogen (H i), radio surveys to probe the cosmic evolution of H i in galaxies also offer exciting prospects for exploiting OHMs to probe the cosmic history of gas-rich mergers. Using observations for the Looking At the Distant Universe with the MeerKAT Array (LADUMA) deep H i survey, we report the first untargeted detection of an OHM at z &gt; 0.5, LADUMA J033046.20-275518.1 (nicknamed "Nkalakatha"). The host system, WISEA J033046.26-275518.3, is an infrared-luminous radio galaxy whose optical redshift z &#x2248; 0.52 confirms the MeerKAT emission-line detection as OH at a redshift z OH = 0.5225 &#xB1; 0.0001 rather than H i at lower redshift. The detected spectral line has 18.4&#x3C3; peak significance, a width of 459 &#xB1; 59 km s-1, and an integrated luminosity of (6.31 &#xB1; 0.18 [statistical] &#xB1; 0.31 [systematic]) &#xD7; 103 L &#x2299;, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity L FIR = (1.576 &#xB1;0.013) &#xD7; 1012 L &#x2299; marks it as an ultraluminous infrared galaxy; its ratio of OH and infrared luminosities is similar to those for lower-redshift OHMs. A comparison between optical and OH redshifts offers a slight indication of an OH outflow. This detection represents the first step toward a systematic exploitation of OHMs as a tracer of galaxy growth at high redshifts

Looking at the Distant Universe with the MeerKAT Array: Discovery of a luminous OH megamaser at z>0.5z > 0.5

In the local Universe, OH megamasers (OHMs) are detected almost exclusively in infrared-luminous galaxies, with a prevalence that increases with IR luminosity, suggesting that they trace gas-rich galaxy mergers. Given the proximity of the rest frequencies of OH and the hyperfine transition of neutral atomic hydrogen (HI), radio surveys to probe the cosmic evolution of HI in galaxies also offer exciting prospects for exploiting OHMs to probe the cosmic history of gas-rich mergers. Using observations for the Looking At the Distant Universe with the MeerKAT Array (LADUMA) deep HI survey, we report the first untargeted detection of an OHM at $z > 0.5$, LADUMA J033046.20$-$275518.1 (nicknamed "Nkalakatha"). The host system, WISEA J033046.26$-$275518.3, is an infrared-luminous radio galaxy whose optical redshift $z \approx 0.52$ confirms the MeerKAT emission line detection as OH at a redshift $z_{\rm OH} = 0.5225 \pm 0.0001$ rather than HI at lower redshift. The detected spectral line has 18.4$\sigma$ peak significance, a width of $459 \pm 59\,{\rm km\,s^{-1}}$, and an integrated luminosity of $(6.31 \pm 0.18\,{\rm [statistical]}\,\pm 0.31\,{\rm [systematic]}) \times 10^3\,L_\odot$, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity $L_{\rm FIR} = (1.576 \pm 0.013) \times 10^{12}\,L_\odot$ marks it as an ultra-luminous infrared galaxy; its ratio of OH and infrared luminosities is similar to those for lower-redshift OHMs. A comparison between optical and OH redshifts offers a slight indication of an OH outflow. This detection represents the first step towards a systematic exploitation of OHMs as a tracer of galaxy growth at high redshifts