113 research outputs found
Dielectric Properties of the Quasi-Two-Dimensional Electron Liquid in Heterojunctions
A quasi-two-dimensional (Q2D) electron liquid (EL) is formed at the interface
of a semiconductor heterojunction. For an accurate characterization of the Q2D
EL, many-body effects need to be taken into account beyond the random phase
approximation. In this theoretical work, the self-consistent static local-field
correction known as STLS is applied for the analysis of the Q2D EL. The
penetration of the charge distribution to the barrier-acting material is taken
into consideration through a variational approach. The Coulomb from factor that
describes the effective 2D interaction is rigorously treated. The longitudinal
dielectric function and the plasmon dispersion of the Q2D EL are presented for
a wide range of electron and ionized acceptor densities choosing GaAs/AlGaAs as
the physical system. Analytical expressions fitted to our results are also
supplied to enable a widespread use of these results.Comment: 39 pages (in LaTeX), including 8 PostScript figure
Costly mating delays drive female ornamentation in a capital breeder
How fecundity might be traded off with mate attraction and other aspects of reproduction in females remains poorly understood. We investigated these allocation trade-offs using the common glowworm (Lampyris noctiluca), a lampyrid beetle, in which flightless, sedentary females only use resources gathered during the larval stage to attract flying males by glowing. While sexual signaling was not found to have a significant fecundity cost, a delay in successfully attracting a mate greatly increased the risk of reproductive failure, with fecundity losses being more severe in small females. These findings are among the first to show that failure to quickly attract a mate can decrease female fecundity. The results also show how the length of delay before mating can drive the evolution of female sexual ornamentation.Peer reviewe
Axonal Dynamics of Excitatory and Inhibitory Neurons in Somatosensory Cortex
Electrophysiology-delivery of fluorescent viral vectors-and two-photon microscopy were used to demonstrate the rapidity of axonal restructuring of both excitatory and inhibitory neurons in rodent cortical layer II/III following alterations in sensory experience
Status and Prospects of ZnO-Based Resistive Switching Memory Devices
In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges
Metathesis of Electron-Rich Olefins: Structure and Reactivity of Electron-Rich Carbene Complexes
Synapses of Horizontal Connections in Adult Rat Somatosensory Cortex Have Different Properties Depending on the Source of their Axons
Interface and Bulk Trapping Centers in Low Temperature Ion-Beam Sputtered Silicon Dioxide Films
- âŠ