24 research outputs found

    Optimization of electrolysis conditions for ti film electrodeposition from lif-licl eutectic molten salt

    Get PDF
    PRiME 2020, Honolulu, USA, October 4-9, 2020.The optimum conditions for electrodepositing compact, smooth, and adherent Ti films in LiF–LiCl–Li₃TiF₆ at 823 K were investigated. The Li₃TiF₆ was formed in-situ in the melt via comproportionation reaction between Li₂TiF₆ and Ti powder. The solubility of Li₃TiF₆ was confirmed to be higher than 7.1 mol% by cyclic voltammetry and ICP-AES measurement. Galvanostatic electrolysis was conducted on Ni plate substrates at various concentrations of Li₃TiF₆ (0.55, 2.6, 7.1 mol%) and cathodic current density (50–1200 mA cm⁻ÂČ). Ti films with smoother surface were obtained at higher Li₃TiF₆ concentration and lower current density. In the present study, Ti films having the smoothest surface were obtained at 7.1 mol% of Li₃TiF₆ and 50 mA cm⁻ÂČ

    Effects of Temperature, Ti(III) Ion Concentration, and Current Density on Electrodeposition of Ti Films in LiF-LiCl Melt

    Get PDF
    The effects of temperature, Ti(III) ion concentration, and current density on the electrodeposition of Ti films were investigated in the eutectic LiF–LiCl melt at 823–973 K. The Ti(III) ions were prepared by adding Li₂TiF₆ and Ti metal to the melt. The diffusion coefficients of Ti(III) were 1.4, 1.8, 2.3, and 3.2 × 10⁻⁔ mÂČ s⁻Âč, at 823, 873, 923, and 973 K, respectively. Galvanostatic electrolysis was conducted at 823–973 K. The surface roughness (Sa) of the Ti films decreases with decreasing temperature. Thus, the electrodeposition of Ti films was conducted at the lowest temperature of 823 K with various Li3TiF6 concentrations (0.55–7.1 mol%) and cathodic current densities (50–1200 mA cm⁻ÂČ). The Sa was lower at higher Ti(III) ion concentrations and lower current densities. The smoothest Ti films with a Sa of 1.23 ÎŒm and a thickness of 10 ÎŒm were obtained at a cathodic current density of 50 mA cm⁻ÂČ and Li₃TiF₆ concentration of 7.1 mol%

    Distillation of Entanglement between Distant Systems by Repeated Measurements on Entanglement Mediator

    Get PDF
    A recently proposed purification method, in which the Zeno-like measurements of a subsystem can bring about a distillation of another subsystem in interaction with the former, is utilized to yield entangled states between distant systems. It is shown that the measurements of a two-level system locally interacting with other two spatially separated not coupled subsystems, can distill entangled states from the latter irrespectively of the initial states of the two subsystems.Comment: 11 pages, 2 figures; the version accepted for publication in Phys. Rev.

    Roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in an insect

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In insect classical conditioning, octopamine (the invertebrate counterpart of noradrenaline) or dopamine has been suggested to mediate reinforcing properties of appetitive or aversive unconditioned stimulus, respectively. However, the roles of octopaminergic and dopaminergic neurons in memory recall have remained unclear.</p> <p>Results</p> <p>We studied the roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in olfactory and visual conditioning in crickets. We found that pharmacological blockade of octopamine and dopamine receptors impaired aversive memory recall and appetitive memory recall, respectively, thereby suggesting that activation of octopaminergic and dopaminergic neurons and the resulting release of octopamine and dopamine are needed for appetitive and aversive memory recall, respectively. On the basis of this finding, we propose a new model in which it is assumed that two types of synaptic connections are formed by conditioning and are activated during memory recall, one type being connections from neurons representing conditioned stimulus to neurons inducing conditioned response and the other being connections from neurons representing conditioned stimulus to octopaminergic or dopaminergic neurons representing appetitive or aversive unconditioned stimulus, respectively. The former is called 'stimulus-response connection' and the latter is called 'stimulus-stimulus connection' by theorists studying classical conditioning in higher vertebrates. Our model predicts that pharmacological blockade of octopamine or dopamine receptors during the first stage of second-order conditioning does not impair second-order conditioning, because it impairs the formation of the stimulus-response connection but not the stimulus-stimulus connection. The results of our study with a cross-modal second-order conditioning were in full accordance with this prediction.</p> <p>Conclusion</p> <p>We suggest that insect classical conditioning involves the formation of two kinds of memory traces, which match to stimulus-stimulus connection and stimulus-response connection. This is the first study to suggest that classical conditioning in insects involves, as does classical conditioning in higher vertebrates, the formation of stimulus-stimulus connection and its activation for memory recall, which are often called cognitive processes.</p

    Stimulation of the cAMP system by the nitric oxide-cGMP system underlying the formation of long-term memory in an insect

    Get PDF
    The nitric oxide (NO)-cGMP signaling system and CAMP system play critical roles in the formation of multiple-trial induced, protein synthesis-dependent long-term memory (LTM) in many vertebrates and invertebrates. The relationship between the NO-cGMP system and cAMP system, however, remains controversial. In honey bees, the two systems have been suggested to converge on protein kinase A (PKA), based on the finding in vitro that cGMP activates PKA when sub-optimal dose of cAMP is present. In crickets, however, we have suggested that NO-cGMP pathway operates on PKA via activation of adenylyl cyclase and production of cAMP for LTM formation. To resolve this issue, we compared the effect of multiple-trial conditioning against the effect of an externally applied cGMP analog for LTM formation in crickets, in the presence of sub-optimal dose of cAMP analog and in condition in which adenylyl cyclase was inhibited. The obtained results suggest that an externally applied cGMP analog activates PKA when sub-optimal dose of cAMP analog is present, as is suggested in honey bees, but cGMP produced by multiple-trial conditioning cannot activate PKA even when sub-optimal dose of cAMP analog is present, thus indicating that cGMP produced by multiple-trial conditioning is not accessible to PKA. We conclude that the NO-cGMP system stimulates the cAMP system for LTM formation. We propose that LTM is formed by an interplay of two classes of neurons, namely, NO-producing neurons regulating LTM formation and NO-receptive neurons that are more directly involved in the formation of long-term synaptic plasticity underlying LTM formation

    Critical role of nitric oxide-cGMP cascade in the formation of cAMP-dependent long-term memory

    No full text
    Cyclic AMP pathway plays an essential role in formation of long-term memory (LTM). In some species, the nitric oxide (NO)-cyclic GMP pathway has been found to act in parallel and complementary to the cAMP pathway for LTM formation. Here we describe a new role of the NO-cGMP pathway, namely, stimulation of the cAMP pathway to induce LTM. We have studied the signaling cascade underlying LTM formation by systematically coinjecting various “LTM-inducing” and “LTM-blocking” drugs in crickets. Multiple-trial olfactory conditioning led to LTM that lasted for several days, while memory induced by single-trial conditioning decayed away within several hours. Injection of inhibitors of the enzyme forming NO, cGMP, or cAMP into the hemolymph prior to multiple-trial conditioning blocked LTM, whereas injection of an NO donor, cGMP analog, or cAMP analog prior to single-trial conditioning induced LTM. Induction of LTM by injection of an NO donor or cGMP analog paired with single-trial conditioning was blocked by inhibitors of the cAMP pathway, but induction of LTM by a cAMP analog was unaffected by inhibitors of the NO-cGMP pathway. Inhibitors of cyclic nucleotide-gated channel (CNG channel) or calmodulin-blocked induction of LTM by cGMP analog paired with single-trial conditioning, but they did not affect induction of LTM by cAMP analog. Our findings suggest that the cAMP pathway is a downstream target of the NO-cGMP pathway for the formation of LTM, and that the CNG channel and calcium-calmodulin intervene between the NO-cGMP pathway and the cAMP pathway

    A controlled-NOT gate in a chain of qubits embedded in a spin field-effect transistor and its process tomography

    No full text
    We have investigated the realizability of the controlled-no
    corecore