Effects of oxygen vacancy on adhesion of incoherent metal/oxide interface by first-principles calculations

We investigate effects of oxygen vacancies on adhesion behavior of incoherent Ni/MgO(0 0 1) interface with large misfit, based on the density functional theory. We demonstrate that oxygen vacancies at any local atomic configuration of the incoherent geometry enhance the image-chargelike interaction between the ions in MgO and the ion-induced images in Ni, and stabilize adhesion of the Ni/MgO(0 0 1) interface. The adhesion energy of the defective interface is remarkably larger than that of the perfect interface. We also show that force constants of the adhesive interactions near the oxygen vacancies are comparable to the Ni-Mg bond at the perfect interface. The vacancy-induced enhancement of the image electron accumulation hardly contributes to the interfacial stiffness, while it is reduced by losing the covalent Ni-O interaction due to an ontop oxygen vacancy.     

Combination probe for optically assisted ultrasonic velocity-change imaging aimed at detecting unstable blood vessel plaque

Optical Review - Blood vessel plaque with a large lipid core is at risk of becoming thrombus and is likely to induce acute heart disease. To prevent this, it is necessary to determine not only the...     

Effects of oxygen-vacancies in high-temperature cuprate superconductors

We investigate the effects of oxygen vacancies on the magnetic properties and superconducting transition temperature of high-temperature cuprate superconductors. Starting with the d-p Hamiltonian, we simultaneously employ the coherent potential approximation to account for the effects of oxygen vacancies, and the fluctuation-exchange scheme to address the copper-site Coulomb interactions. Our results show that the presence of oxygen vacancies weakens the antiferromagnetic spin fluctuations of d-electrons subsequently lowering the superconducting transition temperature.     

The falling cat as a port-controlled Hamiltonian system

In this article, the falling cat is modeled as two jointed axial symmetric cylinders with arbitrary twist under the constraint of the vanishing total angular momentum. As a control system with the constraint taken into account, this model is formulated as a port-controlled Hamiltonian system defined on the cotangent bundle of the shape space for the jointed cylinders. A control is then designed as a function on the cotangent bundle, according to a standard procedure. Thus, the equations of motion are determined on the cotangent bundle together with the control. The whole motion as a vibrational motion of the falling cat is obtained after integrating the constraint equation of the vanishing total angular momentum. An example of the falling cat is given in which the model turns a somersault to approach a target state in equilibrium with an expected rotation after finishing a vibrational motion.