Analyzing the influencing factors of PMsub.2.5 concentration, scenario simulations, and countermeasure research to address the problem of PMsub.2.5 pollution in Guangdong Province is of great ...significance for governments at all levels for formulating relevant policies. In this study, the ChinaHighPMsub.2.5 dataset and economic and social statistics for Guangdong Province from 2010 to 2019 were selected, and a PMsub.2.5 pollution management compliance path formulation method based on the multi-scenario simulation was proposed by combining the differences in city types and PMsub.2.5 concentration prediction. Based on the prediction model of PMsub.2.5 concentration constructed by the Ridge and SVM models and facing the PMsub.2.5 pollution control target in 2025, the urban PMsub.2.5 pollution control scenario considering the characteristics of urban development was constructed. According to the scenario simulation results of the PMsub.2.5 prediction model, the PMsub.2.5 pollution control path suitable for Guangdong Province during the 14th Five-Year Plan period was explored. The coupling coordination model was used to explore the spatial and temporal pattern evolution of PMsub.2.5 pollution collaborative governance in various prefecture-level cities under the standard path, and the policy recommendations for PMsub.2.5 pollution control during the 14th Five-Year Plan period are proposed. The results showed the following: ① in the case of small samples, the model can provide effective simulation predictions for the study of urban pollutant management compliance pathways. ② Under the scenario of PMsub.2.5 management meeting the standard, in 2025, the annual average mass concentration of PMsub.2.5 in all prefecture-level cities in Guangdong Province will be lower than 22 μg/msup.3, and the annual average concentration of PMsub.2.5 in the whole province will drop from 25.91 μg/msup.3 to 21.04 μg/msup.3, which will fulfil the goal of reducing the annual average concentration of PMsub.2.5 in the whole province to below 22 μg/msup.3, as set out in the 14th Five-Year Plan for the Ecological Environmental Protection of Guangdong Province. ③ Under the path of PMsub.2.5 control and attainment, the regional coordination relationship among prefecture-level cities in Guangdong Province is gradually optimized, the number of intermediate-level coordinated cities will increase, and the overall spatial distribution pattern will be low in the middle and high in the surrounding area. Based on the characteristics of the four city types, it is recommended that a staggered development strategy be implemented to achieve synergy between economic development and environmental quality. Urban type I should focus on restructuring freight transportation to reduce urban pollutant emissions. City type II should focus on urban transportation and greening. For city type III, the focus should be on optimizing the industrial structure, adjusting the freight structure, and increasing the greening rate of the city. For city type IV, industrial upgrading, energy efficiency, freight structure, and management of industrial pollutant emissions should be strengthened.
Human activity plays a crucial role in influencing PM
concentration and can be assessed through nighttime light remote sensing. Therefore, it is important to investigate whether the nighttime light ...brightness can enhance the accuracy of PM
simulation in different stages. Utilizing PM
mobile monitoring data, this study introduces nighttime lighting brightness as an additional factor in the PM
simulation model across various time periods. It compares the differences in simulation accuracy, explores the impact of nocturnal human activities on PM
concentrations at different periods of the following day, and analyzes the spatial and temporal pollution pattern of PM
in urban functional areas. The results show that (1) the incorporation of nighttime lighting brightness effectively enhances the model's accuracy (R
), with an improvement ranging from 0.04 to 0.12 for different periods ranges. (2) the model's accuracy improves more prominently during 8:00-12:00 on the following day, and less so during 12:00-18:00, as the PM
from human activities during the night experiences a strong aggregation effect in the morning of the next day, with the effect on PM
concentration declining after diffusion until the afternoon. (3) PM
is primarily concentrated in urban functional areas including construction sites, roads, and industrial areas during each period. But in the period of 8:00-12:00, there is a significant level of PM
pollution observed in commercial and residential areas, due to the human activities that occurred the previous night.
In order to avoid potential personnel and financial losses, the evaluation of pre-drilling safety is of great importance in oil and gas exploration and development. This paper presents a method of ...evaluating pre-drilling safety through combining the Analytic Hierarchy Process (AHP) with the Alternating Condition Expectation (ACE) method. An indicator system with a 9-3-1 structure was established, incorporating various unrestricted variables to describe the technical factor. Additionally, nine membership functions and weights were determined in order to build the AHP model by connecting the independent variables in the basic layer to dependent variables in the middle layer. Four transformed functions were also formulated to construct the ACE model by linking the middle variables to the pre-drilling safety value in the final layer. A total of 28 sets of on-site drilling data from three oilfields were collected for the establishment and verification of the AHP-ACE model. Average absolute error (AAE) and average absolute relative error (AARE) of the model to predict the training data are 0.03 and 4.29%, respectively, whereas the AAE and AARE for verification samples are 0.03 and 4.51%, respectively. The sensitivity ranking of the three potential variables is as follows: human factor exhibits the highest degree of sensitivity, followed by natural factor and technical factor, in descending order. The AHP-ACE model for pre-drilling safety assessment faces limitations in universal applicability and scope, particularly in real-time drilling activities. However, its potential for improvement lies in integrating insights from past operations and expanding the dataset to enhance accuracy and broaden safety assessment coverage. This method is not limited by blocks, which is of great significance to ensure drilling safety.
While the contribution of biodiversity to supporting multiple ecosystem functions is well established in natural ecosystems, the relationship of the above- and below-ground diversity with ecosystem ...multifunctionality remains virtually unknown in urban greenspaces. Here we conducted a standardized survey of urban greenspaces from 56 municipalities across six continents, aiming to investigate the relationships of plant and soil biodiversity (diversity of bacteria, fungi, protists and invertebrates, and metagenomics-based functional diversity) with 18 surrogates of ecosystem functions from nine ecosystem services. We found that soil biodiversity across biomes was significantly and positively correlated with multiple dimensions of ecosystem functions, and contributed to key ecosystem services such as microbially driven carbon pools, organic matter decomposition, plant productivity, nutrient cycling, water regulation, plant-soil mutualism, plant pathogen control and antibiotic resistance regulation. Plant diversity only indirectly influenced multifunctionality in urban greenspaces via changes in soil conditions that were associated with soil biodiversity. These findings were maintained after controlling for climate, spatial context, soil properties, vegetation and management practices. This study provides solid evidence that conserving soil biodiversity in urban greenspaces is key to supporting multiple dimensions of ecosystem functioning, which is critical for the sustainability of urban ecosystems and human wellbeing.
In this work, a Mg-Zn-Y (ZW31) alloy with good plasticity was introduced into 10 μm 10 vol% SiC
/AZ91 composite materials (PMMCs) via the extrusion compound method, and then the ZW31/PMMC laminate ...was prepared via multi-pass hot rolling. The hot deformation mechanism and elevated temperature tensile fracture mechanism of ZW31/PMMC laminates were studied using the elevated temperature tensile test. The elevated temperature deformation mechanism is influenced by the strain rate. At low strain rates, grain boundary slip is the primary elevated temperature deformation mechanism of the ZW31/PMMC laminate. However, at high strain rates, the activation of pipeline diffusion is facilitated by the particle deformation zone (PDZ) in the PMMC layer with a high dislocation density, leading to the dominance of dislocation climbing as the main mechanism for elevated temperature deformation of the laminate. Additionally, the implementation of a ZW31/PMMC laminate structure effectively inhibits the initiation and propagation of cavities and microcracks within the laminate layer along the normal direction (ND) while simultaneously blunting crack tips via lattice dislocation emission toward the ZW31 layer. Upon cracking of the PMMC layer, stress concentration occurs in the fracture area of the ZW31 layer, ultimately resulting in necking-induced detachment.
The cathode material is one of the main restricting factors for the development of potassium‐ion batteries (PIBs). The poor conductivity, sluggish reaction kinetics, and unstable crystal structure of ...cathode materials have impeded their electrochemical performance. Here, controlled intercalation of TiSe2 with Cu is used to yield a layered superconductor Cu0.11TiSe2, which exhibits increased electrons and ions transfer rates and improved crystal structure stability. The insertion of Cu not only improves the electronic conductivity and reduces the diffusion barrier but also plays a role in crystal structure support, which further leads to a highly reversible charge and discharge process of Cu0.11TiSe2. The layered superconductor Cu0.11TiSe2 exhibits an excellent cycling performance with a capacity retention of 80% after 300 cycles at a current density of 20 mA g−1 and a superior rate capability with a capacity of 45 mAh g−1 at 1000 mA g−1 (≈8C). Furthermore, a full battery assembled with the Cu0.11TiSe2 cathode and graphite anode exhibits a high reversible capacity of 74 mAh g−1 at a current density of 20 mA g−1. This study provides a new path for developing the high‐performance cathode material of PIBs and other alkali metal‐ion batteries.
The layered superconductor Cu0.11TiSe2, which can be obtained by controlled intercalation of TiSe2 with Cu, has increased electrons and ions transfer rates. It exhibits a superior rate capability and long cycling stability as a cathode of potassium‐ion batteries. Cu ions also play a role as a pillar between layers, delivering the highly reversible phase transformations during cycles.
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•Biomimetic silicate–polyvinyl alcohol composite with a tooth enamel biomimetic microstructure was controllably constructed using a novel coaxial printing methodology.•Enamel ...biomimetic structure comprising flexible polyvinyl alcohol and rigid silicate components enhances strength and toughness at multiscale.•The interpenetrated microstructure of biomimetic silicate–polyvinyl alcohol composite effectively blocks crack propagation, addressing the inherent brittleness of silicate-based composites.
The trade-off between strength and toughness in traditional silicate-based materials presents a notable challenge in engineering infrastructure. The limited range of suitable components means that chemical modification does not fully address inherent brittleness. This study introduces a novel coaxial 3D printing method to create tooth enamel biomimetic composites using stiff silicate and flexible polyvinyl alcohol (PVA) as strengthening and toughening agents, respectively. Unlike standard silicate composites, this method produces an interpenetrated microstructure in which silicate and PVA maintain geometric continuity. This biomimetic structure, regulated internal stress, and crack propagation inhibition contribute to the silicate–PVA composites considerably enhanced mechanical properties, including flexural strength (10.3 MPa), ductility (4.68 %), and fracture energy (1.5±0.9×104N/m), beyond the inherent brittleness of pure silicate blocks. In situ characterization and multiscale simulation of stress distribution and deformation behavior further validated multiple toughening mechanisms. These mechanisms include silicate bridge fracture, interface detachment, and PVA rupture, along with complex cracking patterns. The significantly strengthened and toughened biomimetic silicate–PVA composite suggests promising potential for use as a structural material in engineering resilient structures.
Premature ovarian failure (POF) is a common female reproductive disorder and characterized by menopause, increased gonadotropin levels and estrogen deficiency before the age of 40 years old. The ...etiologies and pathogenesis of POF are not fully clear. At present, hormone replacement therapy (HRT) is the main treatment options for POF. It helps to ameliorate perimenopausal symptoms and related health risks, but can't restore ovarian function and fertility fundamentally. With the development of regenerative medicine, bone marrow mesenchymal stem cells (BMSCs) have shown great potential for the recovery of ovarian function and fertility based on the advantages of abundant sources, high capacity for self-renewal and differentiation, low immunogenicity and less ethical considerations. This systematic review aims to summarize the possible therapeutic mechanisms of BMSCs for POF. A detailed search strategy of preclinical studies and clinical trials on BMSCs and POF was performed on PubMed, MEDLINE, Web of Science and Embase database. A total of 21 studies were included in this review. Although the standardization of BMSCs need more explorations, there is no doubt that BMSCs transplantation may represent a prospective therapy for POF. It is hope to provide a theoretical basis for further research and treatment for POF.
Porous materials engineered for rapid liquid absorption are useful in many applications, including oil recovery, spacecraft life-support systems, moisture management fabrics, medical wound dressings, ...and microfluidic devices. Dynamic absorption in capillary tubes and porous media is driven by the capillary pressure, which is inversely proportional to the pore size. On the other hand, the permeability of porous materials scales with the square of the pore size. The dynamic competition between these two superimposed mechanisms for liquid absorption through a heterogeneous porous structure may lead to an overall minimum absorption time. In this work, we explore liquid absorption in two different heterogeneous porous structures three-dimensional (3D) circular tubes and porous layers, which are composed of two sections with variations in radius/porosity and height. The absorption time to fill the voids of porous constructs is expressed as a function of radius/porosity and height of local sections, and the absorption process does not follow the classic Washburn’s law. Under given height and void volume, these two-section structures with a negative gradient of radius/porosity against the absorption direction are shown to have faster absorption rates than control samples with uniform radius/porosity. In particular, optimal structural parameters, including radius/porosity and height, are found that account for the minimum absorption time. The liquid absorption in the optimized porous structure is up to 38% faster than in a control sample. The results obtained can be used a priori for the design of porous structures with excellent liquid management property in various fields.
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