The Exploration of the Food Education Program in Primary and Secondary Schools

Nowadays, unhealthy dietary habits, insufficient food knowledge, and lack of manual skills are typical issues among primary and secondary school students in China. To help students build up a strong constitution and life wisdom, Weifang Hansheng School of Shandong developed a food education course. This paper expounds on the course framework, contents of food education textbooks and the measures to implement the course

Performance Analysis of Different Modulation Techniques for Free-Space Optical Communication System

Free space optical system is a hot topic, which has gaining more and more attention. But,when the signal transmitted in the channel ,the performance could be severely degraded due to the atmosphere turbulent.The purpose of this paper is to find a most suitable modulation method for FSO system under FSO channel.The performance of power efficiencies,bandwidth efficiency,BER and SNR for the four modulation schemes have studied and compared in this paper include On-Off keying (OOK), Binary Phase Shift Keying(BPSK),Differential Phase Shift Keying(DPSK) and Quadrature Phase Shift Keying (QPSK) without atmospheric turbulence. Numerical   experiments show that BPSK and QPSK schemes are better compared to other schemes in BER performance and power requirements. When take intensity scintillation under Gamma-Gamma turbulence channel into consideration and the average BER is derived with Meijer-G function, BER performances of BPSK and QPSK scheme approximate the same .Compared with BPSK,BER performance for QPSK is 3dB lower .From the simulation results, modulation for BPSK is robust resist turbulence. As a result, BPSK scheme is suitable for free-space optical communication system

Thermal, optical, interfacial and mechanical properties of titanium dioxide/shape memory polyurethane nanocomposites

To further understand effects of titanium dioxide (TiO2) nanoparticles on thermal, optical, microstructural, interfacial and mechanical properties of shape memory polyurethane (SMPU), TiO2/SMPU nanocomposites with different TiO2 contents were synthesized. Then various properties of TiO2/SMPU nanocomposites were characterized. Results indicate that the melting temperature of soft segments in SMPU can be used as the shape memory transition temperature of TiO2/SMPU nanocomposites. TiO2 nanoparticles are almost filled in SMPU pores to form compact skeleton structures in TiO2/SMPU when the TiO2 content is 3% by weight. Further, the used TiO2 is rutile phase, and lowers the SMPU crystallinity. The suitable TiO2 content can increase the absorptivity to UV light and enhance the reflectivity to visible light of TiO2/SMPU nanocomposites, lowering its photo-aging properties and prolonging its service life. Also, TiO2/SMPU shows a higher scattering intensity and a faster decreasing trend than SMPU due to the larger electron density difference between TiO2 and SMPU. The microphase separation and ordered structures in SMPU are decreased due to added TiO2 nanoparticles. There are electron density fluctuations at the interfaces between hard and soft phases in SMPU, and between SMPU and TiO2 nanoparticles. Finally, the prpared TiO2/SMPU nanocomposites have better shape memory effects and tensile properties when TiO2 content of 3% is proposed to synthesize TiO2/SMPU nanocomposites for practical engineering applications

Distributed Robust Partial State Consensus Control for Chain Interconnected Delay Systems

Partial state consensus (PSC) is investigated for chain interconnected systems with time-varying delays and parameter uncertainties. A novel design philosophy of PSC control is proposed and a sequential calculation method is presented to guarantee the robustness of the controller. A sufficient condition based on linear matrix inequalities (LMIs) is derived and the stability is proven by the Lyapunov method. The proposed approach can ensure that the states which are subject to a consensus constraint achieve consensus, while those without a consensus constraint track their own set points. Finally, numerical simulations and a solution proportioning experiment are developed to validate the effectiveness of the proposed method

Charge Measurement of Cosmic Ray Nuclei with the Plastic Scintillator Detector of DAMPE

One of the main purposes of the DArk Matter Particle Explorer (DAMPE) is to measure the cosmic ray nuclei up to several tens of TeV or beyond, whose origin and propagation remains a hot topic in astrophysics. The Plastic Scintillator Detector (PSD) on top of DAMPE is designed to measure the charges of cosmic ray nuclei from H to Fe and serves as a veto detector for discriminating gamma-rays from charged particles. We propose in this paper a charge reconstruction procedure to optimize the PSD performance in charge measurement. Essentials of our approach, including track finding, alignment of PSD, light attenuation correction, quenching and equalization correction are described detailedly in this paper after a brief description of the structure and operational principle of the PSD. Our results show that the PSD works very well and almost all the elements in cosmic rays from H to Fe are clearly identified in the charge spectrum.Comment: 20 pages, 4 figure