Search Results (5)

In coastal waters, tributyltin chloride (TBTC), a persistent organic pollutant, is extensively present. It is uncertain, therefore, if exposure to TBTC can harm haarders and how. This study exposed the fish for 60 days in order to investigate the molecular mechanism of haarder following TBTC poisoning. Our findings demonstrated that growth indices dropped, liver tissue was damaged, and the liver’s total tin concentration rose following TBTC exposure. Furthermore, we discovered that blood reactive oxygen species rose while total blood cell count decreased. As malondialdehyde levels rose, total antioxidant capacity and antioxidant enzyme activity (superoxide dismutase, catalase, and glutathione peroxidase) were markedly reduced. After being exposed to TBTC, liver cells displayed clear signs of apoptosis. Differentially expressed genes were primarily linked to oxidative stress, energy metabolism, and apoptosis, according to the transcriptome study of livers. Overall, the long-term stress of TBTC resulted in the antioxidant system being harmed, as well as serious malfunction of the energy metabolism and apoptotic response. Full article

The double-story isolation structure is a novel development based on the mid-story isolation structure. To accurately reflect the seismic response of the double-story isolation structure, this study considers a dynamic elastoplastic analysis model that incorporates soil–structure interaction (SSI). Comparative models of a base-fixed structure and a mid-story isolation structure are also established. The results indicate that the double-story isolation structure has a longer structural period compared to the mid-story isolation structure. Furthermore, the structural period increases as the soil softens and the structure becomes more flexible. When considering SSI on hard soil versus not considering SSI, the double-story isolation structure exhibits smaller base shear, story force, inter-story displacement, maximum acceleration of the top floor, and displacement of the upper isolation layer, indicating the significant shock-absorbing effect of the double-story isolation structure. However, when SSI is considered on soft soil, the shock-absorbing effect of the isolation structure diminishes, and the effectiveness of the double-story isolation structure may not necessarily surpass that of the mid-story isolation structure. In all three soil conditions, the compressive stresses of the isolation bearings in the upper isolation layer of the double-story isolation structure were lower than those in the isolation bearings of the base isolation layer. Additionally, the double-story isolation structure demonstrates reduced compressive stress in the isolation bearings, fewer plastic hinges in the frame, and less stress damage compared to the mid-story isolation structure. Consequently, the risk of overturning damage in the double-story isolation structure is significantly reduced compared to the mid-story isolation structure. The effect of soft ground on structures can be highly detrimental, which should be paid more attention to during the design process. This study offers valuable insights for future research on double-story isolation systems and serves as a reference for the development of high-performance building structures in the future. Full article

Understanding on the spatiotemporal interactions between ecosystem services (ESs) and social–ecological drivers is crucial for the design of sustainable development strategies for coastal wetlands. In this paper, we took the Yellow River Delta (YRD) as a case study, based on multiple evaluation methods to study the spatiotemporal dynamics of ESs in the YRD from 1980 to 2020. With the help of principal component analysis (PCA) for identification of multiple drivers, we researched the spatiotemporal differentiation and influence mechanism of drivers on ESs, using the coupling coordination degree (CCD) model and geographically and temporally weighted regression (GTWR) model, and subsequently provided the development strategy for each district in Dongying City. The results showed that (1) the patterns of ESs were spatially heterogeneous, with a fluctuating upward trend from 1980 to 2020, which was mainly affected by regulating service. (2) Our spatiotemporal analysis of ES interactions identified that cultural service was mainly disorder with other ESs. Nevertheless, in wetlands, various ESs can basically develop in a coordinated manner. (3) We integrated multiple drivers into five principal components by PCA, to which the response of ESs had spatial heterogeneity. (4) Consequently, we integrated spatiotemporal knowledge on ES interactions and their drivers into spatial planning. Full article

During the winters of 2009/2010 and 2020/2021, observations were carried out at an eastern port of Liaodong Bay to examine the variations in sea ice thickness and atmospheric conditions. The daily ice thickness (DIT) and the cumulative ice thickness (CIT) are the two main observation items related to the thickness of sea ice. For DIT, the sea ice thickness gradually decreases as the temperature increases, and the freezing rate a is 1.48 cm/(°C·d)^1/2. For CIT, when the temperature is −12 °C, the maximum growth rate of ice thickness decreases from 3.5 cm/d to 1.5 cm/d as the ice thickness increases from 0 to 20 cm. The residual method was applied to calculate the oceanic heat flux, which is an important parameter of ice modeling, and both the analytic model (Stefan’s law) and numerical model (high-resolution thermodynamic snow-and-ice model) were utilized in this work. It was found that the accuracy of the simulation results was high when the growth coefficient of the analytic mode was 2.3 cm/(°C·d)^1/2. With an oceanic heat flux of 2 W·m⁻², the maximum error of the numerical model approached 60% in 2010 and 3.7% in 2021. However, using the oceanic heat flux calculated in this work, the maximum error can be significantly reduced to 4.2% in the winter of 2009/2010 and 1.5% in 2020/2021. Additionally, the oceanic heat flux in Liaodong Bay showed a decreasing trend with the increase in ice thickness and air temperature. Full article

The Chinese government started an important project “Geographical conditions monitoring (GCM)” in 2012, which aims at fully revealing the spatial pattern of natural resources, and economic and social development. Urban development assessment and analysis are an important topic of the comprehensive statistics in GCM project. This study quantitatively evaluates the sustainable development level of 287 cities at prefecture level and above in China and analyzes their spatial distribution. Both an index system of urban sustainable development (USI) constructed by three aspects, namely society, economy and environment, and the TOPSIS-Entropy method are adopted. The results show that the overall level of urban sustainable development in China is not high, and obvious differences in urban sustainable development among cities exist. The coordination of social, economic and environmental sustainable development in China is at a low level. In terms of spatial distribution, cities from eastern coastal areas of China are at relatively higher levels of sustainable development with central and northeastern cities ranking second and western ones lowest. Several spatial clusters of urban sustainable development can be found. The “High–High” clusters, in which cities have high levels of sustainable development, are distributed in urban agglomerations. Finally, some suggestions have been provided to achieve all-round sustainable development in China. Full article