No abstract

No abstract

Articles you may be interested inInterfacial and coexistence properties of soft spheres with a short-range attractive Yukawa fluid: Molecular dynamics simulations J. Chem. Phys. 136, 154702 (2012); 10.1063/1.3703507 Surface properties of the polarizable Baranyai-Kiss water model A nonadditive methanol force field: Bulk liquid and liquid-vapor interfacial properties via molecular dynamics simulations using a fluctuating charge model J. Chem. Phys. 122, 024508 (2005); 10.1063/1.1827604Effect of uniform electric field on homogeneous vapor-liquid nucleation and phase equilibria. II. Extended simple point charge model water Extensive efforts are currently devoted to the development of water models for computer simulations that explicitly incorporate molecular polarizability. Liquid-vapor coexistence properties for the polarizable point charge ͑PPC͒ model of water are examined in this contribution with the aid of molecular dynamics calculations. An accurate analytical equation of state for the high-temperature states of the PPC model is presented, including its critical region. The liquidvapor coexistence curve and the critical point parameters for the PPC water are extracted from its equation of state. The critical temperature, pressure, and density for the PPC water are found to be within 10% of their experimental values and its critical compression factor is within 2%. The effect of applying an external electric field to the system on the coexistence properties is investigated. A shift of the critical point of water to higher temperature and pressure is observed, a result similar to that of the introduction of an electrolyte to water. A large applied electric field is capable of inducing phase separation of a subcritical fluid on the time scale of a typical simulation run.

No abstract

Wide field-of-view (WFOV) imaging is extensively used in fields as diverse as macro photography, virtual reality, machine vision, and microscopy. Conventional WFOV cameras are bulky since they require multiple refractive lenses. Here, we design, fabricate, and characterize a 100° FOV camera with a total-track length of ∼2 mm, composed of an inverse-designed multi-level diffractive doublet with an input-aperture diameter of 0.204 mm, a back-focal length of 1 mm, and operating at λ = 850 nm (bandwidth ∼ 34 nm). Using careful experiments, we characterize the focusing and imaging performance as well as demonstrate de-vignetting based on experimental calibration. The spatial frequency at 10% modulation-transfer-function contrast was measured at 150 and 38 lp/mm for 0 and 50° incident angles, respectively. Our approach can be scaled to larger aperture sizes and smaller f/#s, potentially leading to thin, lightweight WFOV cameras for portable applications.