Earth, Sun, and Venus

Directed placement of DNA origami could play a key role in future integrated nanoelectronic devices. Here we demonstrated the site-selective attachment of DNA origami on gold dots formed using a pattern transfer method through block copolymer self-assembly. First, a random copolymer brush layer is grafted on the Si surface and then poly (styrene-b-methylmethacrylate) block copolymer is spin-coated to give a hexagonal nanoarray after annealing. UV irradiation followed by acetic acid etching is used to remove the PMMA, creating cylindrical holes and then oxygen plasma etching removes the random copolymer layer inside those holes. Next, metal evaporation, followed by lift-off creates a gold dot array. We evaluated different ligand functionalization of Au dots, as well as DNA hybridization to attach DNA origami to the nanodots. DNA-coated Au nanorods are assembled on the DNA origami as a step towards creating nanowires and to facilitate electron microscopy characterization of the attachment of DNA origami on these Au nanodots. The DNA hybridization approach showed better DNA attachment to Au nanodots than localization by electrostatic interaction. This work contributes to the understanding of DNA-templated assembly, nanomaterials, and block copolymer nanolithography. Furthermore, the work shows potential for creating DNA-templated nanodevices and their placement in ordered arrays in future nanoelectronics.

Sonar sensors play an integral part in underwater robotic perception by providing imagery at long distances where standard optical cameras cannot. They have proven to be an important part in various robotic algorithms including localization, mapping, and structure from motion. Unfortunately, generating realistic sonar imagery for algorithm development is difficult due to the high cost of field trials and lack of simulation methods. To remove these obstacles, we present various upgrades to the sonar simulation method in HoloOcean, our open-source marine robotics simulator. In particular, we improve the noise modeling using a novel cluster-based multipath ray-tracing algorithm, various probabilistic noise models, and material dependence. We also develop and integrate simulated models for side-scan, single-beam, and multibeam profiling sonars.

We report frequency-comb-based measurements of Ca Rydberg energy levels. Counterpropagating laser beams at 390 and 423 nm excite Ca atoms from the 4s^{2 1}S₀ ground state to 4sns¹S₀ Rydberg levels with n ranging from 40 to 110. Near-resonant two-photon two-color excitation of atoms in a thermal beam makes it possible to eliminate the first-order Doppler shift. The resulting line shapes are symmetric and Gaussian. We verify laser metrology and absolute accuracy by reproducing measurements of well-known transitions in Cs, close to the fundamental wavelengths of our frequency-doubled Ti:sapphire lasers. From the measured transition energies we derive the ionization potential of Ca, E_IP=1478154283.42±0.08(statistical)±0.07(systematic) MHz, improving the previous determinations by a factor of 11.

In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks, and gauge fields similar to the SM gluons. We focus on the exploration of such sectors where the dark particles are produced at the LHC through a portal and undergo rapid hadronization within the dark sector before decaying back, at least in part and potentially with sizeable lifetimes, to SM particles, giving a range of possibly spectacular signatures such as emerging or semi-visible jets. Other, non-QCD-like scenarios leading to soft unclustered energy patterns or glueballs are also discussed. After a review of the theory, existing benchmarks and constraints, this work addresses how to build consistent benchmarks from the underlying physical parameters and present new developments for the PYTHIA Hidden Valley module, along with jet substructure studies. Finally, a series of improved search strategies is presented in order to pave the way for a better exploration of the dark showers at the LHC.

Aims. We perform a homogeneous analysis of an unprecedented set of spatially resolved scaling relations (SRs) between interstellar medium (ISM) components, that is to say dust, gas, and gas-phase metallicity, and other galaxy properties, such as stellar mass (M-star), total baryonic content, and star-formation rate (SFR), in a range of physical scales between 0.3 and 3.4 kpc. We also study some ratios between galaxy components: dust-to-stellar, dust-to-gas, and dust-to-metal ratios.

Methods. We use a sample of 18 large, spiral, face-on DustPedia galaxies. The sample consists of galaxies with spatially resolved dust maps corresponding to 15 Herschel-SPIRE 500 mu m resolution elements across the optical radius, with the morphological stage spanning from T = 2 to 8, M-star from 2 x 10(9) to 1 x 10(11) M-circle dot, SFR from 0.2 to 13 M-circle dot yr(-1), and oxygen abundance from 12 + log(O/H) = 8.3 to 8.8.

Results. All the SRs are moderate or strong correlations except the dust-H I SR that does not exist or is weak for most galaxies. The SRs do not have a universal form but each galaxy is characterized by distinct correlations, affected by local processes and galaxy peculiarities. The SRs hold, on average, starting from the scale of 0.3 kpc, and if a breaking down scale exists it is below 0.3 kpc. By evaluating all galaxies together at the common scale of 3.4 kpc, differences due to peculiarities of individual galaxies are cancelled out and the corresponding SRs are consistent with those of whole galaxies. By comparing subgalactic and global scales, the most striking result emerges from the SRs involving ISM components: the dust-total gas SR is a good correlation at all scales, while the dust-H-2 and dust-HI SRs are good correlations at subkiloparsec/kiloparsec and total scales, respectively. For the other explored SRs, there is a good agreement between small and global scales and this may support the picture where the main physical processes regulating the properties and evolution of galaxies occur locally. In this scenario, our results are consistent with the hypothesis of self-regulation of the star-formation process. The analysis of subgalactic ratios between galaxy components shows that they are consistent with those derived for whole galaxies, from low to high redshift, supporting the idea that also these ratios could be set by local processes.

Conclusions. Our results highlight the heterogeneity of galaxy properties and the importance of resolved studies on local galaxies in the context of galaxy evolution. They also provide fundamental observational constraints to theoretical models and updated references for high-redshift studies.

We report the first example of magnetic pair distribution function (mPDF) data obtained through the use of neutron polarization analysis. Using the antiferromagnetic semiconductor MnTe as a test case, we present high-quality mPDF data collected on the HYSPEC instrument at the Spallation Neutron Source using longitudinal polarization analysis to isolate the magnetic scattering cross section. Clean mPDF patterns are obtained for MnTe in both the magnetically ordered state and the correlated paramagnet state, where only short-range magnetic order is present. We also demonstrate significant improvement in the quality of high-resolution mPDF data through the application of ad hoc corrections that require only minimal human input, minimizing potential sources of error in the data processing procedure. We briefly discuss the current limitations and future outlook of mPDF analysis using polarized neutrons. Overall, this work provides a useful benchmark for mPDF analysis using polarized neutrons and provides an encouraging picture of the potential for routine collection of high-quality mPDF data.