Anharmonicity Induced Faster Decay of Hot Phonons in Rutile TiO2 Nanorods: A Raman Spectromicroscopic study

Temperature dependent Raman spectromicroscopy from rutile TiO2 nanorods has been studied here to understand the effect of thermal perturbations on different Raman active phonon modes. The TiO2 nanorods, characterized using...

Integro-Differential Equation for the Non-Equilibrium Thermal Response of Glass-Forming Materials: Analytical Solutions

An integro-differential equation describes the non-equilibrium thermal response of glass-forming substances with a dynamic (time-dependent) heat capacity to fast thermal perturbations. We found that this heat transfer problem could be solved analytically for a heat source with an arbitrary time dependence and different geometries. The method can be used to analyze the response to local thermal perturbations in glass-forming materials, as well as temperature fluctuations during subcritical crystal nucleation and decay. The results obtained can be useful for applications and a better understanding of the thermal properties of glass-forming materials, polymers, and nanocomposites.

Feeling Every Bit of Winter – Distributed Temperature Sensitivity in Vernalization

Temperature intrinsically influences all aspects of biochemical and biophysical processes. Organisms have therefore evolved strategies to buffer themselves against thermal perturbations. Many organisms also use temperature signals as cues to align behavior and development with certain seasons. These developmentally important thermosensory mechanisms have generally been studied in constant temperature conditions. However, environmental temperature is an inherently noisy signal, and it has been unclear how organisms reliably extract specific temperature cues from fluctuating temperature profiles. In this context, we discuss plant thermosensory responses, focusing on temperature sensing throughout vernalization in Arabidopsis. We highlight many different timescales of sensing, which has led to the proposal of a distributed thermosensing paradigm. Within this paradigm, we suggest a classification system for thermosensors. Finally, we focus on the longest timescale, which is most important for sensing winter, and examine the different mechanisms in which memory of cold exposure can be achieved.

Footprints of the Alice Springs Orogeny preserved in far northern Australia: An application of multi-kinetic thermochronology in the Pine Creek Orogen and Arnhem Province

The Precambrian Pine Creek Orogen and Arnhem Province represent two of the oldest basement terrains in northern Australia and are often considered to be devoid of significant regional deformation since the cessation of regional metamorphism in the Paleoproterozoic. A major caveat in the current hypothesis of long lived structural inactivity is the absence of published low-temperature thermochronological data and thermal history models for this area. Here we report the first apatite fission track and (U–Th–Sm)/He data for crystalline samples from both the Pine Creek Orogen and Arnhem Province, complemented with apatite geochemistry data acquired by electron microprobe and laser ablation mass spectrometry methods, and present multi-kinetic low-temperature thermal history models. The thermal history models for the Pine Creek Orogen and Arnhem Province reveal a distinct phase of denudation coeval with the Paleozoic Alice Springs Orogeny. By integrating with previous studies, we suggest that this event deformed a larger area of the Australian crust than previously perceived. Localised Mesozoic thermal perturbations proximal to the Pine Creek Shear-Zone additionally record evidence for Mesozoic reheating contemporaneous with mantle induced subsidence and the onset of sedimentation in the Money Shoal Basin, while the Arnhem Province samples demonstrate no evidence of Mesozoic thermal perturbations.Supplementary material: EPMA protocol comparison, AFT plots and modelling, additional geochemistry, datasets and instrumentation parameters are available at https://doi.org/10.6084/m9.figshare.c.5206664

Perturbative countersurveillance metaoptics with compound nanosieves

The progress of metaoptics relies on identifying photonic materials and geometries, the combination of which represents a promising approach to complex and desired optical functionalities. Material candidate options are primarily limited by natural availability. Thus, the search for meta-atom geometries, by either forward or inverse means, plays a pivotal role in achieving more sophisticated phenomena. Past efforts mainly focused on building the geometric library of individual meta-atoms and synthesizing various ones into a design. However, those efforts neglected the powerfulness of perturbative metaoptics due to the perception that perturbations are usually regarded as adverse and in need of being suppressed. Here, we report a perturbation-induced countersurveillance strategy using compound nanosieves mediated by structural and thermal perturbations. Private information can be almost perfectly concealed and camouflaged by the induced thermal-spectral drifts, enabling information storage and exchange in a covert way. This perturbative metaoptics can self-indicate whether the hidden information has been attacked during delivery. Our results establish a perturbative paradigm of securing a safer world of information and internet of things.