The current study investigates the transient human physiological and comfort responses during sedentary activity following a period of elevated activity in a hot condition. Such metabolic and thermal down-steps are common in buildings as occupants arrive after commuting in summer. It creates a serious problem for thermostatic control, since arriving occupants find their transition uncomfortably warm at temperatures that resident occupants find comfortable. Fifty-nine participants (29 men, 30 women) dressed in 0.6 clo were tested while sedentary for 60 min in 26 °C, after having been exposed to 30 °C for 15min, during which they performed activities metabolically simulating commuting: sitting (SE-1.2 met), or doing three levels of stair-step exercises: low (LEx-2.2 met), medium (MEx-3.0 met), and high (HEx-4.4 met). Subjective comfort and physiological responses (metabolic rate, skin temperature, skin blood flow rate, heart rate, core temperature, and skin wettedness) were collected. Results show that sedentary conditions at 26°C became comfortable and acceptable within 2 min, but thermal sensation required much longer to change from 'warm' or 'hot' to 'neutral': 0, 8, 17, 30 min after SE, LEx, MEx, HEx respectively. Skin wettedness and core temperature did not recover within the60 min. The delays are mainly due to body heat stored during the exercise. A room temperature of 26°C may not provide sufficient cooling after summer commuting. Localized convective cooling of transitional spaces and work areas by ceiling or desk fans represent a way to enhance comfort recovery.

Underwater acoustic communication technology is the core technology in the marine field, occupying a very important position, and has an important supporting role for underwater observation operations and military activities. Underwater acoustic technology is currently the most widely used and longest underwater wireless communication technology. With the increasing demand for development, the complexity of underwater acoustic channels, underwater environment and other factors make the communication speed, communication distance and communication stability of underwater acoustic communication greatly restricted. Despite these limitations, underwater acoustic communication is still valued by professionals from various countries and industries, and has been developed and applied to some extent. This article summarizes the basic content of underwater acoustic communication technology, leads to its general structure as a communication system, the current development of underwater acoustic communication technology, and the characteristics of underwater acoustic communication systems due to the characteristics of underwater acoustic channels. This article summarizes the development and some applications of the underwater acoustic communication system and the full text and some prospects for the future underwater acoustic communication.

BiFeO3 is a photocatalyst with excellent performance. However, its applications are limited due to its wide bandgap. In this paper, MIL-101(Fe)@BiOI composite material is synthesized by hydrothermal method and then calcined at high temperature to obtain BiFeO3@Bi5O7I composite material with high adsorption capacity. Among them, An n-n heterojunction is formed, which improves the efficiency of charge transfer, and the recombination of photo-generated electrons and holes prevents the improvement of photocatalytic efficiency and stability. The result of photocatalytic degradation of tetracycline under visible light irradiation showed, BiFeO3@Bi5O7I (1:2) has the best photodegradation effect, with a removal rate of 86.4%, which proves its potential as a photocatalytic degradation material.

In the study, ZIF-8@BIOI composites were synthesized by the hydrothermal method and then calcined to acquire the ZnO@Bi5O7I composite as a novel composite for the photocatalytic deterioration of the antibiotic tetracycline (TC). The prepared ZnO@Bi5O7I composites were physically and chemically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmet–Teller (BET) surface area, UV–Vis diffuse reflectance spectroscopy (DRS), emission fluorescence spectra, transient photocurrent response, electrochemical impedance spectra and Mott–Schottky. Among the composites formed an n–n heterojunction, which increased the separation efficiency of electrons and holes and the efficiency of charge transfer. After the photocatalytic degradation test of TC, it showed that ZnO@Bi5O7I (2:1) had the best photodegradation effect with an 86.2% removal rate, which provides a new approach to the treatment of antibiotics such as TC in wastewater.