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In this study, the biomass expansion factor (BEF) method was combined with the tree growth function in order to obtain a more accurate growth function of tree species through the fitting of different growth functions to tree growth, and to determine the characteristics of the forest carbon stock as well as the carbon sink potential of Huangshan National Forest Park (HNFP) in China. The carbon sink potential of each tree species and the integrated influencing factors, such as the stand and soil, were directly represented by structural equation modelling (SEM) to clarify the size and path of each influencing factor against the carbon sink potential. The results showed the following: (1) the logistic growth function fitting results for the seven major tree species in HNFP were better than those from the Richard–Chapman growth function, and the R2 was greater than 0.90. (2) In 2014, the total carbon stock of the forest in HNFP was approximately 9.59 × 105 t, and the pattern of carbon density, in general, was higher in the central region and the northeastern region and lower in the northern and southern regions, while the distribution of carbon density was lower in the northern and southern regions. The carbon density pattern generally showed a higher distribution in the central and northeastern regions and a lower distribution in the northern and southern regions; most of the high-carbon-density areas were distributed in blocks, while the low-carbon-density areas were distributed sporadically. (3) The total carbon sink of the forest in HNFP was 8.26 × 103 t in 2014–2015, and due to the large age structure of the regional tree species, the carbon sinks of each tree species and the total carbon sink of HNFP showed a projected downward trend from 2014 to 2060. (4) For different tree species, the influencing factors on carbon sink potential are not the same, and the main influence factors involve slope position, slope, altitude, soil thickness, etc. This study identified the carbon stock and carbon sink values of the forest in HNFP, and the factors affecting the carbon sink potential obtained by SEM can provide a basis for the selection of new afforestation sites in the region as well as new ideas and methods to achieve peak carbon and carbon neutrality both regionally and nationally in the future. [ABSTRACT FROM AUTHOR]

Background: Large-scale vaccine production requires downstream processing that focuses on robustness, efficiency, and cost-effectiveness. Methods: To assess the robustness of the current vaccine production process, three batches of COVID-19 Omicron BA.1 strain hydrolytic concentrated solutions were selected. Four gel filtration chromatography media (Chromstar 6FF, Singarose FF, Bestarose 6B, and Focurose 6FF) and four ion exchange chromatography media (Maxtar Q, Q Singarose, Diamond Q, and Q Focurose) were used to evaluate their impact on vaccine purification. The quality of the vaccine was assessed by analyzing total protein content, antigen content, residual Vero cell DNA, residual Vero cell protein, and residual bovine serum albumin (BSA). Antigen recovery rate and specific activity were also calculated. Statistical analysis was conducted to evaluate process robustness and the purification effects of the chromatography media. Results: The statistical analysis revealed no significant differences in antigen recovery (p = 0.10), Vero HCP residue (p = 0.59), Vero DNA residue (p = 0.28), and BSA residue (p = 0.97) among the three batches of hydrolytic concentrated solutions processed according to the current method. However, a significant difference (p < 0.001) was observed in antigen content. Conclusions: The study demonstrated the remarkable robustness of the current downstream process for producing WIBP-CorV vaccines. This process can adapt to different batches of hydrolytic concentrated solutions and various chromatography media. The research is crucial for the production of inactivated SARS-CoV-2 vaccines and provides a potential template for purifying other viruses. [ABSTRACT FROM AUTHOR]

In this study, polyvinylidene fluoride (PVDF) composite films were prepared by fused deposition modeling, and the effects of ionic liquid (IL) content on the printability, crystallization behavior, and electrical properties of melted PVDF were systematically investigated. The results show that the addition of IL increased the temperature sensitivity of melted PVDF and decreased its viscosity, while IL acted as a plasticizer to lower the melting point of PVDF and improve its FDM printability. The imidazole cations in IL had electrostatic interactions with the -CF2- groups in PVDF, which promoted the transformation of the nonpolar phase to the polar phase in PVDF; thus, the addition of IL was beneficial to the increase in the polar β phase. The PVDF with 20 wt.% IL contained the highest proportion of β phase content (32.59%). Moreover, the increase in polar β-phase content also increased the polarization strength of PVDF and improved its ferroelectric properties. PVDF with 10 wt.% IL had the highest residual polarization strength (16.87 μC/m2). [ABSTRACT FROM AUTHOR]

Pipeline leakage causes enormous safety and economic concerns; therefore, sensors which are high-performance and durable are in high demand for improving monitoring accuracy and for avoiding economic loss. In this work, mica-based flexible PZT sensors showed high sensitivity, with 140 mV N−1 and 467 mV N−1 for the output voltage, with regard to the tapping and bending modes, respectively. They can monitor airflow in normal conditions with high sensitivity and a linearity of 424 mV MPa−1 and 0.99, respectively. In the event of a pipeline leak, the mica-based sensors exhibited a rapid response time as short as 0.578 s. Furthermore, they generated distinct voltage levels at different distances from the leakage point, thus providing valuable information for accurately locating the source of the leakage. [ABSTRACT FROM AUTHOR]

Due to the unique electromechanical energy conversion capability of ferroelectric materials, they have been at the forefront of materials science for a variety of applications such as sensors, actuators and energy harvesting. Researchers have focused on exploring approaches to achieve improved ferroelectric performance, and to ensure that the available material systems are more environmentally friendly. This comprehensive review summarizes recent research progress on porous ceramics and highlights the variety of factors that are often ignored, namely the influence of porosity on the Curie temperature, and applications of porous ferroelectric materials with adjustable Curie temperature. Finally, the development trends and challenges of porous ferroelectric materials are discussed, aiming to provide new insights for the design and construction of ferroelectric materials. [ABSTRACT FROM AUTHOR]

Antibiotics in water have attracted increasing attention due to their potential threat to aquatic ecosystems and public health. Most previous studies have focused on heavily polluted environments, while ignoring urbanized rivers with high population density. Taking Suzhou Creek in Shanghai as an example, this study attempted to explore the antibiotic pollution characteristics of typical urbanized rivers. Further, it screened out priority antibiotics so as to provide reference for the regular monitoring of antibiotics in urban surface water in the study's later stage. Four classes of 27 antibiotics in surface water samples and sediment samples were detected and analyzed by SPE-UPLC-MS/MS under both wet season and dry season. Results demonstrate that the total amount of antibiotics detected reached 1936.9 ng/L and 337.3 ng/g in water samples and sediment samples, respectively. Through Pearson correlation analysis, it can be shown that there is a very significant correlation between a variety of antibiotics in water and sediment. The results of ecological risk assessment based on risk quotient (RQ) show that certain antibiotics presented high and medium risk to the surrounding ecosystem. Finally, the priority antibiotics selected by optimized priority screening method were EM, SPD, CLR and RTM. Therefore, we have proven that the antibiotics being discharged in urbanized rivers show different types of antibiotics, while presenting a toxicological risk to certain species. [ABSTRACT FROM AUTHOR]

Dielectric composites based on ferroelectric ceramics nanofibers are attracting increasing attention in capacitor application. In this work, the sol–gel method and electrospinning technology are utilized to prepare one-dimensional Na0.5Bi0.5TiO3 (NBT) nanofibers, and the influence of electrospinning process parameters such as spinning voltage, liquid supply rate, and collector speed on the morphology and structure of nanofibers are systematically explored. The final optimized parameters include the applied voltage of 20 kV, the solution flow rate of 1 mL/h, and the collector's rotation speed of 1500 rpm. The optimized NBT nanofibers are introduced into the PVDF polymer matrix for energy storage application. Owing to the enhanced interfacial polarization between PVDF matrix and NBT nanofibers with a high aspect ratio, the NBT–PVDF nanocomposites achieve a high discharge energy density of 14.59 J cm−3 and an energy efficiency of 53.69% at 490 kV mm−1, which are higher than those of pure PVDF, i.e., 10.26 J cm−3 and 48.17% at 420 kV mm−1, respectively. The results demonstrate that the strategy of synthesizing NBT nanofibers using the electrospinning method is of great potential for high-performance dielectric capacitor application. [ABSTRACT FROM AUTHOR]

Global greening over the past 30 years since 1980s has been confirmed by numerous studies. However, a single-dimensional indicator and non-spatial modelling approaches might exacerbate uncertainties in our understanding of global change. Thus, comprehensive monitoring for vegetation's various properties and spatially explicit models are required. In this study, we used the newest enhanced vegetation index (EVI) products of Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 to detect the inconsistency trend of annual peak and average global vegetation growth using the Mann–Kendall test method. We explored the climatic factors that affect vegetation growth change from 2001 to 2018 using the spatial lag model (SLM), spatial error model (SEM) and geographically weighted regression model (GWR). The results showed that EVImax and EVImean in global vegetated areas consistently showed linear increasing trends during 2001–2018, with the global averaged trend of 0.0022 yr−1 (p < 0.05) and 0.0030 yr−1 (p < 0.05). Greening mainly occurred in the croplands and forests of China, India, North America and Europe, while browning was almost in the grasslands of Brazil and Africa (18.16% vs. 3.08% and 40.73% vs. 2.45%). In addition, 32.47% of the global vegetated area experienced inconsistent trends in EVImax and EVImean. Overall, precipitation and mean temperature had positive impacts on vegetation variation, while potential evapotranspiration and vapour pressure had negative impacts. The GWR revealed that the responses of EVI to climate change were inconsistent in an arid or humid area, in cropland or grassland. Climate change could affect vegetation characteristics by changing plant phenology, consequently rendering the inconsistency between peak and mean greening. In addition, anthropogenic activities, including land cover change and land use management, also could lead to the differences between annual peak and mean vegetation variations. [ABSTRACT FROM AUTHOR]

Operationalization of sustainability assessments is necessary to promote the sustainable development of agroecosystems. However, primarily, focus has been on the development of sustainability assessment tools with less attention on whether these are suitable for adoption and implementation in specific areas. This drawback could lead to inappropriate management guidance for agricultural practices. Hence, three extensively used models, i.e., the Driver–Pressure–State–Impact–Response (DPSIR) framework, ecological footprint (EF), and emergy analysis (EMA), were applied to quantify the sustainability performance of the agroecosystems in 27 cities in the Yangtze River Delta Urban Agglomeration (YRDUA), China, in 2016. The models were compared using the Pearson correlation analysis and natural break method, to determine a more adaptive method for agricultural sustainability assessments. The level of agricultural sustainable development of each city varied according to the methodology considered for its calculation. Compared with the EMA model, the DPSIR and EF models showed a better relationship (Pearson correlation coefficient of 0.71). The DPSIR model more accurately represented regional rankings of the agricultural sustainability at the municipality level due to its comprehensive consideration of multiple dimension factors and significance for policy making. However, each methodology has its own contribution depending on the study objectives. Hence, different models should be used for adequate determination of agricultural sustainable development at different regional scales; this would also enable better implementation of agricultural practices as well as policies in any given agricultural area for promoting the sustainable development of agroecosystems. [ABSTRACT FROM AUTHOR]

A simple method for the controllable synthesis of Au nanocrystals–metal selenide hybrid nanostructures via amino acid guiding strategy is proposed. The results show that the symmetric overgrowth mode of PbSe shells on Au nanorods can be precisely manipulated by only adjusting the initial concentration of Pb2+. The shape of Au–PbSe hybrids can evolve from dumbbell-like to yolk-shell. Interestingly, the plasmonic absorption enhancement could be tuned by the symmetry of these hybrid nanostructures. This provides an effective pathway for maneuvering plasmon-induced energy transfer in metal–semiconductor hybrids. In addition, the photoactivities of Au–PbSe nanorods sensitized TiO2 electrodes have been further evaluated. Owing to the synergism between effective plasmonic enhancement effect and efficient interfacial charge transfer in these hybrid nanostructures, the Au–PbSe yolk-shell nanorods exhibit an outstanding photocurrent activity. Their photocurrent density is 4.38 times larger than that of Au–PbSe dumbbell-like nanorods under light irradiation at λ > 600 nm. As a versatile method, the proposed strategy can also be employed to synthesize other metal–selenide hybrid nanostructures (such as Au–CdSe, Au–Bi2Se3 and Au–CuSe). [ABSTRACT FROM AUTHOR]

Piezoelectric fiber composites (PFC) have shown excellent performance in the areas of vibration control and deformation control. The viscosity and rigidity of the epoxy resin before and after curing, respectively, were very important factors that affected the performance of PFC. In this paper, Aradite 2020, DP 460, and DP 490 epoxy resins, with the viscosities of 0.15, 25.0, and 250.0 Pa·s, respectively, were employed to encapsulate the piezoelectric fiber composite. The PFC that was packaged with Araldite 2020 had the best free strain of 1420 ppm and tip displacement of 17.8 mm. DP 490 caused the lowest performance of PFC, due to the highest viscosity. When the environmental temperature increased from −40 to +80 °C, the free strain of PFC with Aradite 2020 increased at first and then decreased, reaching a maximum value of 1440 ppm at 30 °C, which was mainly related to the mismatch of the resin/ceramic thermal expansion coefficient. [ABSTRACT FROM AUTHOR]

In this study, polyvinylidene fluoride (PVDF) composite films were prepared by fused deposition modeling, and the effects of ionic liquid (IL) content on the printability, crystallization behavior, and electrical properties of melted PVDF were systematically investigated. The results show that the addition of IL increased the temperature sensitivity of melted PVDF and decreased its viscosity, while IL acted as a plasticizer to lower the melting point of PVDF and improve its FDM printability. The imidazole cations in IL had electrostatic interactions with the -CF 2 - groups in PVDF, which promoted the transformation of the nonpolar phase to the polar phase in PVDF; thus, the addition of IL was beneficial to the increase in the polar β phase. The PVDF with 20 wt.% IL contained the highest proportion of β phase content (32.59%). Moreover, the increase in polar β-phase content also increased the polarization strength of PVDF and improved its ferroelectric properties. PVDF with 10 wt.% IL had the highest residual polarization strength (16.87 μC/m 2 ).