Formation of thick, high energy density, flexible solid supercapacitors is challenging because of difficulties infilling gel electrolytes into porous electrodes. Incomplete infilling results in a low ...capacitance and poor mechanical properties. Here we report a bottom-up infilling method to overcome these challenges. Electrodes up to 500 μm thick, formed from multi-walled carbon nanotubes and a composite of poly(3,4-ethylenedioxythiophene), polystyrene sulfonate and multi-walled carbon nanotubes are successfully infilled with a polyvinyl alcohol/phosphoric acid gel electrolyte. The exceptional mechanical properties of the multi-walled carbon nanotube-based electrode enable it to be rolled into a radius of curvature as small as 0.5 mm without cracking and retain 95% of its initial capacitance after 5000 bending cycles. The areal capacitance of our 500 μm thick poly(3,4-ethylenedioxythiophene), polystyrene sulfonate, multi-walled carbon nanotube-based flexible solid supercapacitor is 2662 mF cm
at 2 mV s
, at least five times greater than current flexible supercapacitors.
Radiation resistance reduces patient survival and is an important challenge in treating lung adenocarcinoma (LUAD). Previous studies have shown that histone H2A variants can affect the ...radiosensitivity of tumors; however, the main role of histone H2A variants in LUAD remains unclear. Using the TCGA database, we found that histone H2A variant H2A.Z.1 is positively associated with the progression and poor prognosis of LUAD. Colony formation, scratch wound-healing, and transwell assays as well as Western blot were performed to assess the role of H2A.Z.1 in vitro. Results suggested that H2A.Z.1 promoted cell migration and invasion, epithelial-mesenchymal transition, stemness, and radiation resistance in LUAD cells. Targeting H2A.Z.1 in combination with radiation therapy could be a potential therapeutic approach for radiation resistant LUAD.
•H2A.Z.1 expression is closely related to the clinical characteristics of LUAD.•H2A.Z.1 is dysregulated in LUAD and correlated with poor prognosis.•Silencing H2A.Z.1 inhibits migration, invasion, and epithelial-mesenchymal transition in A549 and H1975 cells.•H2A.Z.1 contributes to radioresistance in LUAD cells.
This is the first study to estimate the association globally between violence in childhood on educational outcomes, addressing a significant gap in the current evidence base. Systematic reviews and ...meta-analyses were conducted to identify 67 and 43 studies respectively from 21 countries to estimate the relationship between different types of violence in childhood on educational outcomes including school dropout/graduation, school absence, academic achievement and other educational outcomes such as grade retention, learning outcomes and remedial classes. Findings show that all forms of violence in childhood have a significant impact on educational outcomes. Children who have experienced any form of violence in childhood have a 13% predicted probability that they will not graduate from school. Males who are bullied are nearly three times more likely to be absent from school and girls who have experienced sexual violence have a three-fold increased risk of being absent, AOR 2.912, 95% CI (0.904-4.92) and AOR 3.147, 95% CI (0.033-4.57) respectively. Violence in childhood also has a significant impact on children's academic achievement on standardized tests. This study shows how different forms of violence in childhood contribute to inequalities in education-for both boys and girls and that an increased investment in prevention is needed in order to meet the global Sustainable Development Goals of ending violence, raising learning outcomes and creating safe, non-violent and inclusive learning environments. More work is also needed to further define, monitor and measure the link between violence in childhood and educational outcomes in order to achieve the Sustainable Development Goals.
Internal short circuit (ISCr) detection of a battery is critical for preventing thermal runaway and enhancing electrical vehicle safety. In this paper, the electrical characteristics of the ISCr of a ...large format lithium ion battery are analyzed using the equivalent circuit model (ECM). An ISCr detection method is developed based on battery consistency within the battery pack. The ISCr detection method employs the recursive least square (RLS) algorithm based on the mean-difference model (MDM), which is derived from the ECMs consisting of the mean and difference value of cells' voltage and resistance. The algorithm first estimates the basic parameters of the MDM. Then the algorithm calculates the characteristic parameters, such as the differential of the voltage and the fluctuation function of the internal resistance, derived from the basic parameters of the MDM. These characteristic parameters obviously vary once ISCr occurs, thereby helping the battery management system to realize ISCr detection. The effectiveness of the ISCr detection method is validated through a series of experiments.
•Theoretical foundation and practical method of ISCr detection are introduced.•The influence of ISCr on cells' OCV and internal resistance has been discussed.•The effectiveness of the ISCr detection method is validated through experiments.•The specific time consumed to detect ISCr is compared.
•Private tutoring is positively associated with student academic achievement.•Tutored students have higher levels of self-confidence and parent-child relationship.•The positive effects decrease with ...high-intensity private tutoring.
Private tutoring has become a remarkable feature around the world, particularly in East Asia. While much of the studies have focused on the effect of private tutoring on student academic performance, its potential spillovers have been largely neglected. Using data from the China Education Panel Survey (CEPS), this study not only investigates the relationship between private tutoring and academic achievement of Chinese junior high school students but explores the associations of tutoring with student emotional well-being and parent-child relationship. Our study shows that private tutoring is significantly and positively associated with student test scores, especially for subjects of English and mathematics. Furthermore, tutored students tend to report higher levels of self-confidence and parent-child relationship. However, with the intensity of private tutoring increases after a given threshold, its positive effects would be gradually declined. One possible reason examined in this study is that the parental involvement on student homework assistance and leisure activities are crowded out by the high-intensity tutoring. Implications for future research and public policy concerning private tutoring services are discussed.
Background Despite substantial evidence in developed countries showing that child maltreatment can lead to serious life-long consequences, relatively few studies so far have examined the associations ...between childhood maltreatment and adulthood outcomes in developing countries, such as China. It also remains unclear as to the impact of relative poverty on the long-term development of maltreated children. Objective This study aims to investigate the associations between childhood maltreatment and educational, health, and economic outcomes among middle-aged Chinese, as well as explore the moderating effects of relative poverty. Participants and setting The participants of this study were the middle-aged respondents (aged 45 to 59) in the 2011, 2013, and 2015 China Health and Retirement Longitudinal Studies (CHARLS) and the CHARLS Life History Survey (N = 24,114). Methods Physical abuse and emotional neglect were measured to investigate childhood maltreatment. Subjective and objective indicators were used to examine relative poverty. A broad range of midlife outcomes were explored, including educational attainment, physical health, mental health, cognitive functions, labor force participation, wage expenditure, and financial strain. Data analyses were conducted using fixed effects model for panel data and a propensity score matching approach. Results Childhood physical abuse and emotional neglect were both significantly associated with lower levels of midlife educational attainment, cognitive functions, individual wages, and household expenditures, as well as higher rates of chronic diseases, depressive symptoms, poverty, and welfare involvement. Childhood physical abuse also predicted higher risks of difficulty performing the activities of daily living (ADL), unemployment, and fewer work hours. Early-life exposure to relative poverty was linked to a greater likelihood of childhood maltreatment and mid-life adversities. It further aggravated the negative impacts of childhood maltreatment on middle-age outcomes. Conclusion Child maltreatment had a profound effect on long-term child development and midlife outcomes in Chinese contexts. Relative poverty in early life was a moderator that exacerbated the outcomes associated with childhood maltreatment.
Gel polymer electrolytes (GPEs) are one of the most promising candidates to solve safety issues such as liquid leaking, fire, and explosions in battery systems. In this work, novel phosphonate-based ...porous cross-linked gel polymer electrolytes were synthesized by in situ thermal polymerization and applied to sodium-ion batteries. The phosphorus containing GPEs have a high ionic conductivity of 6.29 × 10 −3 S cm −1 and an excellent electrochemical stability of up to 4.9 V ( vs. Na + /Na), and thus could be used as possible non-flammable electrolytes. The Na 3 V 2 (PO 4 ) 3 /GPE/Na cell using GPEs and a Na 3 V 2 (PO 4 ) 3 cathode yields a high capacity of 110.7 mA h g −1 at 1C rate. Moreover, an excellent long-term cycling stability at 5C rate was observed, retaining 81.8% and 69.2% capacity after long-term 4500 and 10 000 cycles, respectively. When cycled at high temperature (60 °C), the sodium-ion Na 3 V 2 (PO 4 ) 3 cell with the GPE also exhibits superior cycling stability compared to a battery with a conventional liquid electrolyte. The excellent cycling performances of the SnS 2 /GPE cell and full cell of SnS 2 /NVP were also observed, holding great promise for the production of safer phosphonate-containing battery systems.
The corrosion of aluminum current collectors and the oxidation of solvents at a relatively high potential have been widely investigated with an aim to stabilize the electrochemical performance of ...lithium-ion batteries using such components. The corrosion behavior of aluminum current collectors was revisited using a home-build high-precision electrochemical measurement system, and the impact of electrolyte components and the surface protection layer on aluminum foil was systematically studied. The electrochemical results showed that the corrosion of aluminum foil was triggered by the electrochemical oxidation of solvent molecules, like ethylene carbonate, at a relative high potential. The organic radical cations generated from the electrochemical oxidation are energetically unstable and readily undergo a deprotonation reaction that generates protons and promotes the dissolution of Al3+ from the aluminum foil. This new reaction mechanism can also shed light on the dissolution of transitional metal at high potentials.
World models learn the consequences of actions in vision-based interactive systems. However, in practical scenarios like autonomous driving, noncontrollable dynamics that are independent or sparsely ...dependent on action signals often exist, making it challenging to learn effective world models. To address this issue, we propose Iso-Dream++, a model-based reinforcement learning approach that has two main contributions. First, we optimize the inverse dynamics to encourage the world model to isolate controllable state transitions from the mixed spatiotemporal variations of the environment. Second, we perform policy optimization based on the decoupled latent imaginations, where we roll out noncontrollable states into the future and adaptively associate them with the current controllable state. This enables long-horizon visuomotor control tasks to benefit from isolating mixed dynamics sources in the wild, such as self-driving cars that can anticipate the movement of other vehicles, thereby avoiding potential risks. On top of our previous work (Pan et al. 2022), we further consider the sparse dependencies between controllable and noncontrollable states, address the training collapse problem of state decoupling, and validate our approach in transfer learning setups. Our empirical study demonstrates that Iso-Dream++ outperforms existing reinforcement learning models significantly on CARLA and DeepMind Control.
Separator as an important part of lithium-ion batteries, allowing the ion to transfer and preventing the direct contact of anode with cathode, determines the safety of the batteries. In this work, a ...kind of polypropylene/hydrophobic silica-aerogel-composite (SAC) separator is fabricated through combining hydrophobic silica aerogel and polypropylene (PP) separator. The rationally designed SAC effectively increases the thermal stability of the separator with slightly growing weight (the area retention rate is 30% higher than that of the PP separator after being heated for 30 min at 160 °C). In addition, the hydrophobic silica aerogel layer in SAC significantly improves the wettability of PP separator to electrolyte owning to the introduced hydrophobic functional groups of -Si(CH3)3 and porous structure, and the contact angles of SAC separator to several common organic electrolytes (EC/DMC, DMC/DOL, Diglyme) are close to 0°. Electrochemical tests show that the prepared SAC separator can decrease the polarization of Li-ion batteries and leads to improved power performance and cycle stability. And the SAC separator is firm with neglectable abscission after folding 200 times. This work provides a new way to improve the safety and simultaneously reduce the polarization of the batteries, implying promising application potential in power batteries.
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•SAC separator is fabricated by combining hydrophobic silica aerogel and PP separator.•The SAC separator has excellent wettability to several different electrolytes.•The SAC separator can improve the power performance Li-ion batteries.•The SAC separator shows negotiable abscission after folding 200 times.•The obtained SAC separator enhances the safety of Li-ion batteries.
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