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Superfine wool powder was blended and extruded with poly(propylene) (PP) to produce blend pellets, and the extruded pellets were hot‐pressed into a blend film. SEM photographs show that the powder could be uniformly incorporated with PP after extrusion. FT‐IR spectra shows that no substantial changes occurred in the chemical structure of both PP and wool powder in the blend film. X‐Ray diffraction analysis indicates that crystallinity of the blend film was much higher than that of the wool powder and little lower than that of PP. TG‐tested results indicate that the thermal stability of the blend film declined with an increase in the powder content. Endothermic peaks of the wool powder in the blend film become more obvious as the powder content increases. Mechanical properties decline greatly with an increase in the wool powder content in the blend film.magnified image

Ocean internal-wave phenomena occur with the variation in seawater vertical temperature, and most internal-wave detections are dependent on the measurement of seawater vertical temperature. A seawater temperature sensor based on a microfiber knot resonator (MKR) is designed theoretically and demonstrated experimentally in this paper. Especially, the dependences of sensing sensitivity on fiber diameter and probing wavelength are studied. Calculated results show that sensing sensitivity increases with the increasing microfiber diameter with the range of 2.30–3.91 μm and increases with the increasing probing wavelength, which reach good agreement with results obtained by experiments. By choosing the appropriate parameters, the maximum sensitivity measured can reach to be 22.81 pm/°C. The seawater temperature sensor demonstrated here shows advantages of small size, high sensitivity, easy fabrication, and easy integration with fiber systems, which may offer a new optical method to detect temperature of seawater or ocean internal-wave phenomenon and offer valuable reference for assembling micro sensors used for other parameters related to seawater, such as salinity, refractive index, concentration of NO3− and so on.

The solubilities of L-valine in water, ethanol, N,N-dimethylformamide, acetone, and isopropyl alcohol were experimentally measured by the synthetic method over the temperature range from (293.15 to 343.15) K at atmosphere pressure. The solubilities of L-valine in pure solvents increase with increasing temperature and in the following order: acetone < N,Ndimethylformamide < isopropyl alcohol < ethanol < water. The solubilities correlated using the modified Apelblat model show good agreement with the experimental data, and the dissolution enthalpy, dissolution entropy, and the molar Gibbs energy were predicted. The experimental solubilities and the modified Apelblat model can be used as essential data and model in the industrial manufacturing process of L-valine.

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We design an ultrabroadband polarization splitter based on three-core photonic crystal fiber (PCF). A modulation core and two fluorine-doped cores are introduced to achieve an ultrawide bandwidth. The properties of three-core PCF are modeled by using the full-vector finite element method along with the full-vector beam propagation method. Numerical results demonstrate that an ultrabroadband splitter with 320 nm bandwidth with an extinction ratio as low as -20  dB can be achieved by using 52.8 mm long three-core PCF. This splitter also has high compatibility with standard single-mode fibers as the input and output ports due to low splicing loss of 0.02 dB. All the air holes in the proposed structure are circular holes and arranged in a triangular lattice that makes it easy to fabricate.

No abstract

An ultrabroadband polarization splitter based on a modified three-core photonic crystal fiber is proposed. Two fluorine-doped cores and a central microstructured modulation core are introduced to achieve an excellent performance and an ultrawide bandwidth. Numerical simulation demonstrates that the splitter has a bandwidth as wide as 300 nm, with an extinction ratio (ER) as low as -20  dB. At the wavelength of 1.55 μm, the ER reaches -30  dB. All the air holes in our design are circular holes and are arranged in a triangular lattice that is easy to fabricate with the method of stack and draw. A suitable mode field area and a Gaussian-like mode field distribution lead to a low splicing loss that is as low as 0.04 dB when splicing with standard single-mode fibers as the lead-in and lead-out ports.