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Flexible materials with both in-plane and out-of-plane piezoelectric coefficients are needed in the development of advanced nanoelectromechanical systems. However, the challenge is to find flexible materials with the coexistence of in-plane and -out-of-plane piezoelectric responses, which hinders the progress of high-performance piezoelectric sensor development. In this paper, we propose the flexible XMAY2 (X = I; M = Ti, Zr; A = Al, Ga; Y = S, Se) monolayers, which belong to the group III-VI XMAY2 family, which showcase notable in-plane and out-of-plane piezoelectric coefficients. The in-plane (d11) and out-of-plane (d31) piezoelectric coefficients of the XMAY2 monolayers vary from 5.20 to 7.04 pm/V and from −0.23 to 0.48 pm/V, respectively. The large in-plane and out-plane piezoelectric responses coexist (d11 = 7.04 pm/V; d31 = 0.48 pm/V) in the IZrGaS2 monolayer, which is larger than other materials in the XMAY2 family, such as SMoSiN2 (d11 = 2.51; d31 = 0.28 pm/V). In addition, the mechanical and transport properties of XMAY2 demonstrate its impressive flexibility characteristics as well as its efficient electrical conductivity. Due to inversion symmetry breaking in both atomic structure and charge distribution of XMAY2 monolayers, the group III-VI XMAY2 family exhibits a potentially rich scope of applications in the field of piezoelectricity.

The Paris Agreement emphasizes the critical role of forests in addressing climate change and ecological protection. High-quality forestry development is an important aspect of forest conservation. As a core strategy for China’s economic transformation, new-type urbanization is increasingly interacting with high-quality forestry development. This study aims to explore this relationship and analyze its impact mechanism. Taking the representative Yellow River Basin in China as an example, this research uses a benchmark regression model, mediation effect model, and threshold effect model from 2010 to 2022 to quantitatively analyze the impact of new-type urbanization on high-quality forestry development. The results show that (1) new-type urbanization has significantly promoted high-quality forestry development, with an estimated coefficient of 0.325; (2) forestry in different regions exhibits significant differences, with the forestry return coefficients for the upper, middle, and lower reaches being 0.326, 0.213, and −0.359, respectively; (3) technological innovation plays a key role in improving forestry production efficiency, resource diversity, and ecosystem services, with an estimated coefficient of 6.543 for technological innovation; (4) the greater the government support, the larger the impact. The p-value of the double threshold is 0.037. Accordingly, to achieve high-quality forestry development, joint efforts are required at both the national and regional levels in promoting new-type urbanization. At the national level, specific ecological areas should be taken as units, and a collaborative development plan for new-type urbanization and high-quality forestry development should be formulated based on the land spatial planning system. This plan should clarify top policy objectives, set up special funds, establish long-term incentives and supervision mechanisms, and ensure that new urbanization has a positive impact on forestry development. At the regional level, appropriate technological innovations should be introduced based on local characteristics, and differentiated new-type urbanization development policies should be formulated to promote high-quality forestry development in the region.

In the construction process of mass concrete structures, the large temperature gradient due to exothermic hydration makes the mass concrete highly susceptible to cracking. This paper carried out research on temperature control methods of mass concrete for the purpose of ensuring construction quality based on the construction of Fengyi cable-stayed bridge caps. Firstly, the temperature and stress change rule in the concrete pouring process of the caps was analyzed though the finite element method (FEM). Then, targeted-oriented comprehensive temperature control schemes were formulated according to the structural characteristics and construction environment of the cap, including the optimization of the material ratio, the arrangement of crack-resistant reinforcing steel, the design of a water pipe cooling scheme and reasonable maintenance. Finally, the whole bridge cap construction process using the optimized water pipe cooling solution was monitored, and the temperature gap between inside and outside the concrete satisfied the specification requirements rigorously. In the concrete demolding session, the concrete surface was smooth and no cracks were found, which indicates the temperature control scheme is reasonable and effective. The research results have reference significance for the pouring and temperature control of mass concrete for bridge caps.