Green, newly felled bamboo stems are prone to cracking during the drying process due to the growth stress and moisture gradient. To improve the drying quality and dimensional stability of bamboo stems, this study applied hygrothermal treatment under atmospheric pressure to newly felled bamboo stems. The temperature, relative humidity, and duration of the treatment were optimized using an orthogonal L₉ (3⁴) experimental design. The results show that the surface color of round bamboo became more uniform after hygrothermal treatment. Furthermore, hygrothermal treatment could reduce the cuticular wax and silicon layer detachment on the surface of round bamboo after drying. According to the range and variance analysis, the relative humidity had the greatest impact on dimensional stability, followed by treatment duration, whereas the temperature had a limited effect. The swelling rate of round bamboo under a hygrothermal treatment at a relative humidity of 95%, a temperature of 95 °C, and a duration of 3 h was decreased 53.72% and 62.76% compared with untreated round bamboo after moisture or water absorption for 7 d, respectively. However, no significant difference was observed in the color of the round bamboo under different hygrothermal treatment conditions. Overall, this study suggests that hygrothermal treatment could be a highly promising technology for improving the dimensional stability of newly felled bamboo stems.

Nowadays, AI reconstructs the human lifestyle. Smart devices are no longer cold machines but 24-hour standby "life assistants" in people's pockets. According to the 55th Statistical Report on the Development of the Internet in China, the number of Internet users in China had reached 1.108 billion by December 2024. And the Internet penetration rate had risen to 78.6%. This means that user interface (UI) design has a huge potential market in China. With the high popularity of digital products, the first impression of the user interface (UI) plays a pivotal role in the user experience. Norman's emotional design theory focuses on emotional interaction between human and products. He defines the emotional design as three levels: visceral, behavioral, and reflective. In the digital era, interface design should consider users’ emotions to enhance human-computer interaction (HCI). This study, based on Norman’s emotional theory, investigates the influence of skeuomorphic aesthetics for middle-aged Chinese users on visceral appeal. On the visceral level, the aesthetic appeal of user interface (UI) can trigger emotional resonance and create a strong first impression, thereby effectively constructing users' loyalty toward a digital product. The initial presentation of visual effects, sound cues, and material texture can directly affect the user's preference and trust in the product. UI designers widely employ skeuomorphic design as a design style. This is because it draws on the appearance and texture of real objects and can arouse users' association with the real world. However, compared with flat design, there is still debate about whether skeuomorphic design can attract strong interest from specific user groups on a visceral level. In China's Internet environment, middle-aged users are immigrants in the digital age. Their aesthetic level and user habits differ from the young generation, who are digital natives. The preference of middle-aged Chinese users for skeuomorphic design has not been fully studied. This study aims to explore the influence of aesthetic elements on skeuomorphic UI design for middle-aged Chinese users. Meanwhile, the identification of UI symbols from middle-aged Chinese users is also revealed in this research.