Researchers used pot experiments to investigate, through measuring plant physiological and biochemical indicators, soil nutrient elements and enzyme activities, as well as analyzing the gene expression of Astragalus sinicus L, that earthworms can mitigate the negative effects of polypropylene microplastics (PP-MPs) on plant growth and further explore the mechanisms of this mitigation.

Abstract

Purpose – We investigate the interconnectedness between the financial sectors and new energy companies in China from the perspective of the multilayer network, and analyze the static and time-varying characteristics of the multilayer network at system and company levels, respectively.

Design/methodology/approach – We employ the multilayer network containing the realized volatility (RV here after) layer, the realized skewness (RS here after) layer and the realized kurtosis (RK here after) layer. The three realized indicators adopted to construct the multilayer network are generated by the intraday trading data from 2012 to 2022.

Findings – (1) Different layers have different characteristics, and can provide supplementary information. (2) Banks tend to play the role of risk transmitters on the whole, while the insurances and new energy companies tend to play the role of risk receivers on average. (3) The connectedness strength of financial sectors and new energy companies varies over time, and climbs sharply during the major crisis events. The roles of financial sectors and new energy companies may change from risk transmitters to risk receivers, and vice versa.

Originality/value – We adopt three realized indicators to construct the three-layer network, which provides a more comprehensive perspective for understanding the connectedness between the financial sectors and new energy companies in China.

The non-uniform pore size distribution and high flammability of commercial separators pose significant challenges to the safe application of high-energy-density lithium-ion batteries. In this study, a flame-retardant composite separator (P@HLi) with high thermal stability was successfully developed, which not only suppressed lithium dendrite growth but also improved high-temperature cycling performance of batteries and significantly enhanced their thermal safety. Li//Li symmetric batteries equipped with P@HLi-20 separators demonstrated stable cycling for over 600 h at a low polarization potential (approximately 50 mV), effectively reducing the formation of “dead lithium” and lithium dendrites. The LFP//Li and NCM811//Li cells with P@HLi-20 separators delivered initial discharge specific capacities of 142.0 and 167.9 mAh/g, respectively. Notably, the LFP//Li battery with P@HLi-20 separator showed excellent high-temperature cycling performance, maintaining 98.0% capacity retention and a discharge capacity of 131.1 mAh/g after 100 cycles at 1 C at 90 °C. Furthermore, pouch cells assembled with P@HLi-20 separators exhibited reductions of 52.67% in peak heat release rate (PHRR) and 68.42% in total heat release (THR) compared to those using Celgard separators, demonstrating superior thermal safety. These results confirm that the P@HLi separator offers comprehensive improvements in both electrochemical performance and safety characteristics.

A research team has developed a causal deep learning model to personalize corticosteroid therapy for intensive care unit patients with sepsis. Using data from patients across two major databases, the model accurately identified which patients would benefit, not benefit, or be harmed by treatment. Patients with severe metabolic acidosis and circulatory dysfunction showed the greatest survival benefit. This breakthrough could potentially optimize critical care decisions, reduce treatment risks, and improve survival rates in sepsis.

In the study, researchers identified top-performing covalent organic frameworks (COFs) for both adsorption and membrane separation, showing that 3D COFs with small pores excel in adsorption, while 2D COFs with large pores are ideal for membrane separation. The team also uncovered key features governing COFs' separation performance, pointing to more efficient ways to extract helium from natural gas.

Composite polymer electrolytes (CPEs) offer a promising solution for all-solid-state lithium-metal batteries (ASSLMBs). However, conventional nanofillers with Lewis-acid–base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously. Here, by regulating the surface charge characteristics of halloysite nanotube (HNT), we propose a concept of lithium-ion dynamic interface (Li⁺-DI) engineering in nano-charged CPE (NCCPE). Results show that the surface charge characteristics of HNTs fundamentally change the Li⁺-DI, and thereof the mechanical and ion-conduction behaviors of the NCCPEs. Particularly, the HNTs with positively charged surface (HNTs⁺) lead to a higher Li⁺ transference number (0.86) than that of HNTs⁻ (0.73), but a lower toughness (102.13 MJ m⁻³ for HNTs⁺ and 159.69 MJ m⁻³ for HNTs⁻). Meanwhile, a strong interface compatibilization effect by Li⁺ is observed for especially the HNTs⁺-involved Li⁺-DI, which improves the toughness by 2000% compared with the control. Moreover, HNTs⁺ are more effective to weaken the Li⁺-solvation strength and facilitate the formation of LiF-rich solid–electrolyte interphase of Li metal compared to HNTs⁻. The resultant Li|NCCPE|LiFePO₄ cell delivers a capacity of 144.9 mAh g⁻¹ after 400 cycles at 0.5 C and a capacity retention of 78.6%. This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.

Abstract

Purpose – Testing several approaches for implied volatility modeling and forecasting.

Design/methodology/approach – Comparative empirical study with four traded options.

Findings – Non-parametric higher-order spline is better than parametric stochastic volatility inspired (SVI) in China.

Research limitations/implications – Our results imply that even though popular on Wall Street, SVI seems not to be utilized by traders and market-makers in China.

Practical implications – Traders may consider higher-order splines as a better method for implied volatility modeling and forecasting.

Originality/value – Propose to model and forecast implied volatility via the fifth-order spline interpolation as a first; initiates studies of the empirical performance of SVI and the fifth-order spline models in implied volatility modeling and forecasting.