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Modified eggshell adsorbent was prepared with 5% potassium permanganate solution to adsorb phosphorus in simulated wastewater. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to clarify their phosphorus removal mechanisms. Isothermal and kinetic equations were fitted to explain the mechanism of phosphorus adsorption. The results showed that the optimum conditions were as follows: phosphorus concentration of 5 mg·L-1, wastewater pH of 2, adsorbent dosage of 3.5 g, adsorption time of 350 min, phosphorus adsorption rate of modified eggshell was 90.81%, and the experimental results were relatively stable. According to the characterization, the eggshell adsorbent has good crystallinity, irregular surface structure and abundant pore channels，and the main functional groups on the surface are hydroxyl (-OH) and C-H groups, which enhanced the adsorption effect.

This design introduces the theoretical basis of digital audio embedding and de-embedding, and proposes a solution that Verilog language can be used to achieve 3G-SDI audio embedding and de-embedding. SDI video and audio data are input to the FPGA, and the audio signals can be embedded in the SDI line blanking after processing. Moreover, some auxiliary information is embedded in the SDI data, when you need these auxiliary information, you need to use the audio de-embedding process. The process of audio de-embedding is inversed with the process of embedding. It has been proved through practice that this scheme can effectively embed digital audio in SDI data stream, synchronize audio and video data, and can de-embed audio signal. The design is very versatile and can improve the efficiency of the design, thus effectively reducing the cost of the product.

The dependence on foreign trade of China and European Union are both at a relatively high level, and the space for Sino-EU trade is still enormous. So, this paper adopts cointegration analysis and error correction model to study the relationship between Sino-EU trade and economic growth from a long-term and short-term perspective respectively. Cointegration analysis shows that: whether it is Sino-EU trade and China’s economic growth or Sino-EU trade and EU’s economic growth, there exists long-term cointegration relationship between them. Sino-EU trade plays a more important role in economic growth of China than its role in stimulating economic growth of European Union. Error correction model demonstrates that Sino-EU trade may deviate from its long-run equilibrium with economic growth in the short run.