China Jiliang University

About: China Jiliang University is a education organization based out in Hangzhou, China. It is known for research contribution in the topics: Fiber optic sensor & Optical fiber. The organization has 9291 authors who have published 8932 publications receiving 95279 citations. The organization is also known as: China Institute of Metrology.

Density and Phonon-Stiffness Anomalies of Water and Ice in the Full Temperature Range.

Abstract: The specific-heat difference between the O:H van der Waals bond and the H-O polar-covalent bond and the Coulomb repulsion between electron pairs on adjacent oxygen atoms determine the angle-length-stiffness relaxation dynamics of the hydrogen bond (O:H-O), which is responsible for the density and phonon-stiffness oscillation of water ice over the full temperature range. Cooling shortens and stiffens the part of relatively lower specific-heat, and meanwhile lengthens and softens the other part of the O:H-O bond via repulsion. Length contraction/elongation of a specific part always stiffens/softens its corresponding phonon. In the liquid and in the solid phase, the O:H bond contracts more than the H-O elongates, hence, an O:H-O cooling contraction and the seemingly "regular" process of cooling densification take place. During freezing, the H-O contracts less than the O:H elongates, leading to an O:H-O elongation and volume expansion. At extremely low temperatures, the O:H-O angle stretching lowers the density slightly as the O:H and the H-O lengths change insignificantly. In ice, the O-O distance is longer than it is in water, resulting in a lower density, so that ice floats.

An Optical Fiber Curvature Sensor Based on Two Peanut-Shape Structures Modal Interferometer

Abstract: A novel curvature sensor based on optical fiber modal interferometer is demonstrated. It consists of two peanut-shape structures that are formed only by single mode fibers. The two peanut-shape structures can split and recombine the core and cladding modes, consequently, it produces modal interference. The experimental results show that the shift of the peak wavelength is almost linearly proportional to the change of curvature, and the sensitivities of the sensors with the lengths of 21, 26, and 30 mm are -18.46, -21.87, and 13.68 nm/m-1, respectively. The proposed curvature sensor is simple, high sensitive, and inexpensive.

Density, Elasticity, and Stability Anomalies of Water Molecules with Fewer than Four Neighbors.

Abstract: Goldschmidt–Pauling contraction of the H–O polar-covalent bond elongates and polarizes the other noncovalent part of the hydrogen bond (O:H–O), that is, the O:H van der Waals bond, significantly, through the Coulomb repulsion between the electron pairs of adjacent oxygen (O–O). This process enlarges and stiffens those H2O molecules having fewer than four neighbors such as molecular clusters, hydration shells, and the surface skins of water and ice. The shortening of the H–O bond raises the local density of bonding electrons, which in turn polarizes the lone pairs of electrons on oxygen. The stiffening of the shortened H–O bond increases the magnitude of the O1s binding energy shift, causes the blue shift of the H–O phonon frequencies, and elevates the melting point of molecular clusters and ultrathin films of water, which gives rise to their elastic, hydrophobic, highly-polarized, ice-like, and low-density behavior at room temperature.