Heavy metals have become ecotoxicological hazards owing to their tendency to not degrade but accumulate in the vital organs of biological bodies. Biosorption is now an efficient method to purify industrial wastewater containing toxic heavy metal ions by using biomass as sorbents. In this work, mimicking the fabricating process of "Tofu", soy protein was heatdenatured and transformed into soy protein hollow microspheres (SPMs) with a diameter of about 4−45 μm, which were then used as biosorbents to remove heavy metal ions in the water system. The trace amount of remaining metal ions was tested by atomic absorption spectroscopy, and the sorption kinetic and isotherm models were calculated and set up to describe the adsorption behavior. The results showed adsorption capacities of Zn(II), Cr(III), Cd(II), Cu(II), Pb(II), and Ni(II) by SPMs at 70°C of 254.95, 52.94, 120.83, 115.01, 235.56, and 177.11 mg/g, respectively, which are much higher than that of many other natural polymeric sorbents. The pseudofirst-order kinetic model and Freundlich isotherm model were well correlated to the experimental data. Overall, SPMs were efficient sorbents for binding heavy metal ions, and their sorption capacities were dependent on factors like denaturation content, temperature, time, pH, and initial ionic concentration.

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To fulfill the dual-frequency requirements, elements are needed to resonate at two different, independently adjustably frequencies. A low weight, low cost, and easy to fabricate single-layer dual-frequency reflectarray is designed, fabricated, and measured, with gain values of 27 and 29.2 dBi at 20 and 30 GHz, respectively.

With the development of urbanization, the environment is the key to the safety of residents’ life and health and the United Nations’ Sustainable Development Goals (SDGs). Urban environmental changes and microclimate problems have attracted widespread attention. For the SDGs, monitoring the urban microclimate more accurately and effectively and ensuring residents’ environmental health and safety is particularly important when designing applications that can replace the traditional fixed-point urban environment or pollution monitoring. Based on the BeiDou Navigation Satellite System platform, this paper proposes a fine-granularity urban microclimate monitoring method using wearable multi-source (PM2.5, PM10, and other air pollutants) sensors innovatively, which includes the satellite position function by adopting the satellite pseudo-range differential positioning technology, environmental data perception through the embedded system and wireless transmission, as well as the GIS data processing and analysis system. The wearable sensor acquires position and service information data through the satellite positioning system and acquires environmental parameters through integrated mobile multi-source sensors. The data are cached and wirelessly transmitted to the cloud server for digital processing. The urban microclimate is evaluated and visualized through algorithm and map API. Mobile monitoring can be flexibly applied to complex and diverse urban spaces, effectively realizing all-weather, all-directional, and accurate microclimate monitoring of urban environmental quality.

Enlarging or reducing the antenna beam width of antennas can improve the positioning capability of detection systems. A miniaturized and easily fabricated ultra-wideband (UWB) antenna system for long-distance electromagnetic detection is proposed in this article. Two ultra-wideband Vivaldi antennae were designed. One was the transmitting antenna with a beam width of 90° or above, the other was a narrow beam antenna array with beam width less than 10°, as a receiving antenna. Both proposed antennae feature broadside gain diagrams with stable radiation patterns and wideband impedance matching in the frequency range between 2.5 GHz and 4 GHz. After detecting their frequency and time-domain behaviors, the detection system can achieve measurements covering a radius of 30 m.

A method of measuring the shielding effectiveness of the irregular cavity is proposed in this paper. An electromagnetic topology model of the irregular cavity is established according to the characteristics of the irregular cavity, and the electromagnetic field distribution characteristics inside the irregular cavity are obtained based on the simulation of the field distribution of the irregular cavity. Combined with the test method of regular cavity shielding effectiveness, the characterization and testing methods of the shielding effectiveness of the irregular cavity are given comprehensively, which compared with the conventional testing method, verifies how effectively the shielding effectiveness of the irregular cavity is tested.

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