The paper examined the spectral characteristics of shallow water waves, which was based on the wave data collected along the south coast of Jiangsu. It proposes a tentative spectra model which can work better than Joint North Sea Wave Project (JONSWAP)spectra. Both of the value of tentative spectral parameters (α and γ) increase with significant wave height and spectral peak frequency. According to a regression analysis, empirical equations are achieved, which is related to the parameters with significant wave height and spectral peak frequency. The study shows that the measured wave spectra can be represented by tentative spectra, and the fitting results in high-frequency tail of tentative spectra are better than that of JONSWAP spectrum with modified parameters.

Keywords: FeSi 2 , first-principle, band structure, density of state. Abstract. Electronic structures and optical properties of bulk β-FeSi 2 are investigated in detail by first principles pseudo-potential methods based on the density function theory. The calculated results show that β-FeSi 2 is a quasidirect band gap material with gap value of 0.74eV. The density of states is mainly composed of Fe 3d and Si 3p states. The dielectric constant, absorption coefficient, and the conductivity are also given. The results are compared with previous theoretical calculation and the available experimental data.

Construction of metal selenides with a large specific surface area and a hollow structure is one of the effective methods to improve the electrochemical performance of supercapacitors. However, the nano-material easily agglomerates due to the lack of support, resulting in the loss of electrochemical performance. Herein, we successfully design a three-dimensional graphene (3DG) encapsulation-protected hollow nanoboxes (CoSe2-SnSe2) composite aerogel (3DG/CoSe2-SnSe2) via a co-precipitation method coupled with self-assembly route, followed by a high temperature selenidation strategy. The obtained aerogel possesses porous 3DG conductive network, large specific surface area and plenty of reactive active sites. It could be used as a flexible and binder-free electrode after a facile mechanical compression process, which provided a high specific capacitance of 460 F g-1 at 0.5 A g-1, good rate capability of 212.7 F g-1 at 10 A g-1, and excellent cycle stability due to the fast electron/ion transfer and electrolyte diffusion. With the as-prepared 3DG/CoSe2-SnSe2 as positive electrodes and the AC (activated carbon) as negative electrodes, an asymmetric supercapacitor (3DG/CoSe2-SnSe2//AC) was fabricated, which delivered a high specific capacity of 38 F g-1 at 1A g-1 and an energy density of 11.89 W h kg-1 at 749.9 W kg-1, as well as a capacitance retention of 91.1% after 3000 cycles. This work provides a new method for preparing electrode material.

According the work arrangements and requirements of carried satellite emergency communications, Fujian Meteorological Bureau establishes a satellite emergency communication system for radar stations to meet the needs of data transmission under the radar state of emergency. This paper introduces the main construction content, structure diagram, network diagram, drills and emergency communications procedures of the emergency communication system for the province's meteorological radar satellite and provides the test emergency situation of the province's meteorological radar-satellite data transmission. Satellite emergency communication system can basically meet the needs of emergency radar data transmission.

Amorphous Al2O3 doped Er2O3 films were deposited on Si(001) substrates by radio frequency magnetron sputtering technique. Emission spectra exhibit a strong emission band around 410 nm and a series of emission band near 970, 980, 1018, 1042 and 1080nm. Ellipsometry measurements show that the refractive indexof the ErAlO films in the region of 400～1000 nm is between 1.76-1.83. The reflectivity of the ErAlO on Si is much smaller than that of clean Si and pure Er2O3 films. All the results indicate that ErAlO could be a promising material for Si solar cells.