The emergence of the millimeter wave (mm-Wave; 30 GHz to 300 GHz) frequency band holds a lot of promise for addressing the congestion at low frequency in future mobile networks. Among many mm-Wave generation schemes, optical heterodyning is considered one of the most promising approaches due to its scalability and potential for integration on chip. Employing optical frequency combs (OFC) for optical heterodyning alleviates the significant phase distortions/noise introduced by the optical sources.
View Article and Find Full Text PDFChironomids commonly dominate macroinvertebrate assemblages in aquatic habitats and these non-biting midges are known for their ability to tolerate contaminants. Studies regarding the interplay between gut microbiota and host detoxification ability is currently a point of interest. Cytochrome P450s (P450s) are critical metabolic enzymes in which a subset is involved in xenobiotic detoxification.
View Article and Find Full Text PDFEcotoxicol Environ Saf
October 2022
Chironomids are characterized by their ubiquitous distribution, global diversity and tolerant ability to deal with environmental stressors. To our knowledge, this is the first study presenting the gut microbial structure of chironomid larvae and examining the microbial alteration induced by invading chlorpyrifos and copper with different dosages. Lethal bioassay displayed a significantly decreased percentage survival of Propsilocerus akamusi larvae exposed to 800 mg/L copper and 50 μg/L chlorpyrifos at 96 h.
View Article and Find Full Text PDFWe report on the epitaxial strain-driven electronic and antiferromagnetic modulations of a pseudospin-half square-lattice realized in superlattices of (SrIrO_{3})_{1}/(SrTiO_{3})_{1}. With increasing compressive strain, we find the low-temperature insulating behavior to be strongly suppressed with a corresponding systematic reduction of both the Néel temperature and the staggered moment. However, despite such a suppression, the system remains weakly insulating above the Néel transition.
View Article and Find Full Text PDFElectric fields can transform materials with respect to their structure and properties, enabling various applications ranging from batteries to spintronics. Recently electrolytic gating, which can generate large electric fields and voltage-driven ion transfer, has been identified as a powerful means to achieve electric-field-controlled phase transformations. The class of transition metal oxides provide many potential candidates that present a strong response under electrolytic gating.
View Article and Find Full Text PDFThe formation of an electric double layer in ionic liquid (IL) can electrostatically induce charge carriers and/or intercalate ions in and out of the lattice which can trigger a large change of the electronic, optical, and magnetic properties of materials and even modify the crystal structure. We present a systematic study of ionic liquid gating of exfoliated 2D molybdenum trioxide (MoO) devices and correlate the resultant electrical properties to the electrochemical doping via ion migration during the IL biasing process. A nearly 9 orders of magnitude modulation of the MoO conductivity is obtained for the two types of ionic liquids that are investigated.
View Article and Find Full Text PDFDue to lattice mismatch between epitaxial films and substrates, in-plane strain fields are produced in the thin films, with accompanying structural distortions, and ion implantation can be used to controllably engineer the strain throughout the film. Because of the strain profile, local defect energetics are changed. In this study, the effects of in-plane strain fields on the formation and migration of oxygen vacancies in KTaO are investigated using first-principles calculations.
View Article and Find Full Text PDFWe investigate the solvation shell structures, the distribution of protonic defects, mechanistic details, kinetics, and dynamics of proton transfer for an excess proton in bulk water and for an excess proton in an aqueous solution of triethylene glycol (TEG) via Car-Parrinello molecular dynamics simulations. The PW91, PBE, and PBE with the Tkatchenko-Scheffler (TS) density-dependent dispersion functionals were used and compared for bulk water and the TEG-water mixtures. The excess proton is found to reside predominantly on water molecules but also resides on hydroxyl groups of TEG.
View Article and Find Full Text PDFMagnetic anisotropy (MA) is one of the most important material properties for modern spintronic devices. Conventional manipulation of the intrinsic MA, i.e.
View Article and Find Full Text PDFThe emergence of two-dimensional metallic states at the LaAlO3/SrTiO3 (LAO/STO) heterostructure interface is known to occur at a critical thickness of four LAO layers. This insulator to-metal transition can be explained through the "polar catastrophe" mechanism arising from the divergence of the electrostatic potential at the LAO surface. Here, we demonstrate that nanostructuring can be effective in reducing or eliminating this critical thickness.
View Article and Find Full Text PDFThe recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain.
View Article and Find Full Text PDFIntrinsic point defect complexes in SrTiO3 under different chemical conditions are studied using density functional theory. The Schottky defect complex consisting of nominally charged Sr, Ti and O vacancies is predicted to be the most stable defect structure in stoichiometric SrTiO3, with a relatively low formation energy of 1.64 eV per defect.
View Article and Find Full Text PDFThe interstitial loop is a unique signature of radiation damage in structural materials for nuclear and other advanced energy systems. Unlike other bcc metals, two types of interstitial loops, 1/2<111> and <100>, are formed in bcc iron and its alloys. However, the mechanism by which <100> interstitial dislocation loops are formed has remained undetermined since they were first observed more than fifty years ago.
View Article and Find Full Text PDFJ Phys Condens Matter
September 2012
The fundamentals of the framework and the details of each component of the self-evolving atomistic kinetic Monte Carlo (SEAKMC) are presented. The strength of this new technique is the ability to simulate dynamic processes with atomistic fidelity that is comparable to molecular dynamics (MD) but on a much longer time scale. The observation that the dimer method preferentially finds the saddle point (SP) with the lowest energy is investigated and found to be true only for defects with high symmetry.
View Article and Find Full Text PDFOrganized defect clusters in non-stoichiometric LiNbO₃ are known to dominate macroscale ferroelectric properties; yet the detailed nature of these defects is currently unknown. Here, the relative stabilities of various defect cluster arrangements of lithium vacancies around a niobium antisite in LiNbO₃ are determined using density functional theory combined with thermodynamic calculations. Their effects on the ferroelectricity of the system are also discussed.
View Article and Find Full Text PDF