Symbol or substance? Environmental regulations and corporate environmental actions decoupling.

Our paper focuses on how firms strategically respond to environmental regulations on environmental actions. Given the greater discretion in environmental information disclosure and relaxed environmental regulations enforcement in China, we propose that firms tend to say more while do less to obtain environmental legitimacy, namely corporate environmental actions decoupling. Using a sample of 5422 Chinese firm-year observations over the period of 2012-2018, we document that stringent environmental regulations contribute to a significant inconsistency between environmental reporting and actual environmental performance. Moreover, we demonstrate that this inconsistency is exacerbated when firms possess greater bargaining power and fewer financial resources. Our paper not only advances the understanding of how firms navigate external regulations by examining the tradeoffs between symbolic and substantive actions, but also sheds light on factors influencing decoupling/greenwashing practices from the perspective of government-business relations in China, and potentially in other emerging economies.

Topology optimization of the azimuth-rotation-independent polarization conversion metasurface for bandwidth enhancement.

Metasurfaces offer an unprecedented opportunity for flexible manipulation of electromagnetic wave. The azimuth-rotation-independent (ARI) polarization conversion metasurface (PCM) is an ultrathin device, which could convert an arbitrary linearly-polarized incident wave to its cross-polarized state. However, the bandwidth of an ARI PCM with a high cross-polarized transmission is usually limited. Here, a topology optimization method of multi-feature points based on the differential evolution (DE) algorithm is adopted to enhance the bandwidth of the traditional ARI PCM while maintaining a high transmission and polarization conversion ratio. The simulated results of the optimized structure indicate a 2.08 times bandwidth expansion in the cross-polarization conversion compared with the original structure. In addition, the measured results are consistent with the simulated ones and the ARI characteristic is validated. The proposed method provides a promising route for efficient high-performance metasurface designs.

Study of symmetries of chiral metasurfaces for azimuth-rotation-independent cross polarization conversion.

The realization of cross-polarization conversion has attracted great interest in polarization conversion metasurfaces (PCMs), particularly due to polarization manipulation of electromagnetic (EM) waves with small size and low loss. An azimuth-rotation-independent (ARI) cross-polarization converter is a kind of 90° polarization rotator, which can rotate the polarization of linearly polarized incident electromagnetic (EM) waves with an arbitrary polarization direction to the orthogonally polarized transmitted EM waves. In this paper, we study the symmetry properties of chiral metasurfaces using the Jones matrix method for ARI 90° polarization rotators. The previous designs could only address C4 symmetry, but with this approach, the derived unit cell structure of the ARI PCM should possess Cn(n ≥ 3, n ∈ N+) symmetry. To confirm the design concept, two chiral structures with different symmetries are investigated by full-wave numerical simulations. The experimental results are also carried out and excellently agree with the simulated results. It could be used for polarization conversion applications and further utilized in antenna applications, polarization detection, and telecommunication applications.

Temporal and spatial variations of meteorological elements and reference crop evapotranspiration in Alpine regions of Tibet, China.

Reference evapotranspiration (ET0) is an important parameter for characterization of the hydrological cycle, and it is also important for agricultural, environmental, and other studies. In this study, by collecting the daily meteorological data of 31 base stations in high-altitude areas of Tibet for 35 consecutive years, the daily reference crop evapotranspiration (ET0) of each base station is calculated by the ASCE Penman-Monteith formula. The Mann-Kendall method is applied primarily to test the trend of meteorological elements and ET0. In addition, the software ArcGIS was used to generate spatial interpolation distribution maps of meteorological elements and ET0 so that the spatio-temporal variation trend of each base station is carried out. The ET0 in Shigatse shows an insignificant downward trend, while the other six regions show an upward trend, which is related to temperature and humidity directly with R2 of 0.23 and 0.67. The relative humidity (RH) and sunshine duration (SD) in Tibet show an overall three-step distribution in the east, middle, and west with RH decreasing from east to west and SD increasing from east to west. Annual cumulative ET0 of Ngari is the largest and decreases from west to east gradually, while ET0 increasing from east (lower elevation) to west (higher elevation) of Tibet with ranging from 730 to 1255 mm/year. This study not only is important for understanding of ET0 changes but also provides the preliminary and elementary reference for agricultural water management in Tibet with high elevation.

Local government responses to catalyse sustainable development: Learning from low-carbon pilot programme in China.

Though there has been a proliferation of strategies and initiatives formulated at both national and international levels to catalyse sustainable development, most are, in effect, implemented in the subnational jurisdictions. Therefore, it is important to address how local government responds to catalyse sustainable development under an environmental decentralisation regime. Prior studies focusing on environmental decentralisation come mainly from developed countries, whereas our paper examines how local governments in China involved in a low-carbon pilot programme react to stringent environmental regulations (ERs) from central government, reflected by changes in land transfer of pollution-intensive industries (PIIs). Our results show that a low-carbon pilot programme reduces land transfer of PIIs by 34.45 ha, due mainly to a decrease in the number of small PII projects. Meanwhile, our research furthers the understanding of environmental decentralisation literature by showing that public awareness, fiscal imbalance, and market-oriented reform can improve local enforcement. Besides, our study contributes to understanding the mixed effect of ERs on firm location, which is likely to be driven by the socio-economic conditions of jurisdictions. Our study also provides practical implications for catalysing sustainable development in those countries with traits of environmental decentralisation and disparate development.