Thomsonbunn7657
The origin of the negative charge at water/air interface was proved to be not only specific adsorption of OH
ions but that of HCO
and/or CO
ions in the previous study [1]. To determine which anionic species is primarily responsible for the surface charge, the surface density of ions in the Stern layer is numerically evaluated from foam-film thickness of aqueous solutions of NaHCO
and Na
CO
.
Equilibrium thickness (equivalent thickness at equilibrium) of the foam films formed from aqueous solutions of NaHCO
and Na
CO
was measured as a function of electrolyte concentration at 298.15K.
Applying a modified Poisson-Boltzmann (PB) equation developed for various kinds of electrolytes to the equilibrium thickness gave the surface density of ions in the Stern layer for NaHCO
and Na
CO
systems. From the concentration dependence of the surface density together with that for NaCl and NaOH in the previous study [1], the negative surface charges for water and very dilute solutions were found to be due to specific adsorption of HCO
ions. The surface charge at high electrolyte concentration is determined by the specific adsorption of electrolyte anions. The specific-adsorption ability of anion increases in the order CO
≫ HCO
> OH
≫ Cl
.
OH-≫ Cl-.Nano-semiconductor materials coupled with piezoelectric effect have received extensive attention due to their wide application in catalysis. In this work, few-layered MoSe2 nanosheets were grown vertically on TiO2 nanorods (TNr) to synthesize a direct Z-scheme heterojunction, exhibiting efficient piezocatalytic and piezo-photocatalytic performance. The MoSe2/TNr heterostructure exhibited superior piezoelectric degradation efficiency, successfully removing over 98% of RhB within 360 s under continuous magnetic stirring in dark. Compared with piezocatalysis, the piezo-photocatalytic system possessed higher degradation efficiency and cycle stability. Furthermore, a piezo-photoelectric synergistic effect of nanocomposites was observed by current outputs. Under stirring conditions, the current density of depleted MoSe2/TNr and MoSe2 nanosheets were respectively 6.3 μA/cm2 and 5.5 μA/cm2. When light and stirring were applied, the MoSe2/TNr current density increased twice to 13.2 μA/cm2, while the MoSe2 nanosheets didn't exhibit improvement. Through the direct Z-scheme heterojunction of MoSe2/TNr, photoexcitation and piezoelectric polarization work together to effectively replenish carriers under light irradiation, and then rapidly separate free charges through piezopotential. This work broadens the application prospects of piezocatalysis and piezo-photocatalysis in renewable energy harvesting and water purification.Carbonaceous-magnetic composites are the most appealing candidates for electromagnetic wave absorption, and creating hollow interiors and nanopores in the composites is commonly recognized as an essential strategy to reinforce their overall performances. Herein, we propose a spatial confinement strategy mediated by Co2(OH)2CO3 nanosheet assemblies for achieving highly dispersed Co nanoparticles into hollow porous N-doped carbon shells (HP-Co@NCS). Systematic multi-technique characterizations indicate that the Co2(OH)2CO3 nanosheet assemblies simultaneously play a trifunctional role during the synthesis, including Co source, template of the hollow interior cavities, and micro-/mesopore porogen. The chemical composition can be modulated by simply varying the ratio of Co2(OH)2CO3 and carbon source (dopamine). The optimized HP-Co@NCS absorber exhibits a well-defined hollow structure and unprecedented high porosity (specific surface area of 742 m2 g-1) even with a high metallic Co content of 35.8 wt%. These profitable structural characteristics can facilitate incident EM waves penetrating the absorber's interior and promoting multiple reflections and scattering. Therefore, the HP-Co@NCS absorber exhibits efficient microwave absorption ability with a minimum reflection loss of -39.0 dB at a thin thickness of 2.5 mm and an effective absorption bandwidth up to 5.5 GHz (12.5-18.0 GHz) at a thin thickness of 2.0 mm. This work provides a new methodology to design advanced carbonaceous-magnetic composite materials with hollow porous structures for microwave absorption.
Development of soft conductive materials has enabled the promising future of wearable electronics for motion sensing. However, conventional soft conductive materials typically lack robust adhesive and on-demand removable properties for a target substrate. Therefore, it is believed that the integration of superior mechanical properties, electrical conductivity, and tunable adhesive properties into hydrogels would support and improve their reliable sensing performance.
A hydrogel ionic conductor composed of cationic micelles crosslinked in the polyacrylamide (PAM) network was designed and fabricated. The viscoelastic, mechanical, adhesion, electrical, and antimicrobial properties of the hydrogel were systematically characterized.
The developed ionic conductor possesses a range of desirable properties including mechanical performances such as excellent stretchability (>1100%), toughness, elasticity (recovery from 1000% strain), conductivity (2.72 S·m
), and antimicrobial property, owing to the multipleand exhibits a tunable adhesive property (triggerable attachment and on-demand removable capabilities) in adapt to the surrounding environmental conditions (i.e., pH, temperature). With all these significant features, the resulting hydrogel ionic conductor serves as a proof-of-concept motion-sensing system with excellent sensitivity and enhanced reliability for the detection of a wide range of motions.Covalent-organic frameworks (COFs) and related composites show an enormous potential in next-generation high energy-density lithium-ion batteries. However, the strategy to design functional covalent organic framework materials with nanoscale structure and controllable morphology faces serious challenges. In this work, a layer-assembled hollow microspherical structure (Sn@COF-hollow) based on the tin-nitrogen (Sn-N) coordination interaction is designed. Such carefully-crafted hollow structure with large exposed surface area and metal center decoration endows the Sn@COF-hollow electrode with more activated lithium-reaction sites, including Sn ions, carbon-nitrogen double bond (CN) groups and carbon-carbon double bond (CC) units from aromatic benzene rings. Besides, the layer-assembled hollow structure of the Sn@COF-hollow electrode can also alleviate the volume expansion of electrode during repeated cycling, and achieve fast electrons/ions transmission and capacitance-dominated lithium-reaction kinetics, further leading to enhanced cycling performance and rate properties. In addition, the effective combination of the inorganic metal and organic framework components in the Sn@COF-hollow electrode can promote its improved conductivity and further enhance lithium-storage properties. Benefited from these merits, the Sn@COF-hollow electrode delivers highly reversible large capacities of 1080 mAh g-1 after 100 cycles at 100 mA g-1 and 685 mAh g-1 after 300 cycles at 1000 mA g-1. This work provides an interesting and effective way to design COF-based anodes of lithium-ion battery with improved electrochemical performances.Limitations of a polythetic-categorical classification system has sparked ongoing quantitative efforts to establish a valid and reliable method for diagnosing mental illness. Dimensional methods of classification, such as the Hierarchical Taxonomy of Psychopathology (HiTOP), have been found to ameliorate the limitations of a categorical approach - despite the provisional placement of a Somatoform spectrum. The current investigation sought to elucidate the placement of the Somatoform spectrum within the HiTOP model, and to further corroborate discriminant and convergent validity of the Somatoform spectrum. Using a sample of patients seeking chronic low-back pain treatment (n = 200), superior model fit suggested Somatoform fits better as a separate spectrum from Internalizing and placing Somatoform as a subfactor of Internalizing did not improve model fit. Discriminant and convergent validity with an external criteria demonstrated distinctiveness of the Somatoform spectrum from the Internalizing spectrum in the HiTOP model.Attentional function in substance use disorder (SUD) is not well understood. To probe attentional function in SUD as a function of primary substance of abuse, we administered the attentional network task (ANT) to 44 individuals with Cocaine Use Disorder (CoUD), 49 individuals with Cannabis Use Disorder (CaUD), 86 individuals with Opioid Use Disorder (OUD), and 107 controls with no SUD, along with the stop-signal task (SST). The ANT quantifies the effects of (temporal) alerting cues and (spatial) orienting cues to reduce reaction time (RT) to targets, as well as probing how conflicting (target-incongruent) stimuli slow RT. The SST quantifies individuals' ability to inhibit already-initiated motor responses. After controlling for sex representation and age, OUD and CaUD participants showed blunted alerting effects compared to controls, whereas CaUD and CoUD participants showed greater stimulus conflict (flanker) effects. Finally, CoUD participants showed a trend toward increased orienting ability. In SST performance, no SUD group showed a prolonged stop-signal reaction compared to controls. However, the OUD group (and CoUD group at trend level) showed prolonged "go" RT to targets and reduced hit rates. These data indicate differences in attentional function in persons with SUD as a function of the primary substance use.Veterans who served in post-9/11 conflicts and experience deployment trauma sequelae frequently endorse disability and dissatisfaction with life. Although correlated, disability and life dissatisfaction represent distinct constructs with separate implications for quality of life. We examined associations between deployment trauma sequelae, disability and life dissatisfaction in 288 post-9/11 Veterans. Participants completed assessments of psychiatric, somatic and social functioning. Self-reports evaluating disability and life dissatisfaction were used to group participants based on established criteria (i.e., Disability and Dissatisfaction, Disability Only, Dissatisfaction Only, or No Disability or Dissatisfaction). MitoTEMPO Multinomial logistic regressions revealed that greater post-traumatic stress disorder (PTSD) and depressive symptom severity were independently associated with increased odds of being in the Disability and Dissatisfaction group, the Disability Only group and the Dissatisfaction Only group, relative to the No Disability or Dissatisfaction group. Number of prior mild traumatic brain injuries (mTBI) was not associated with disability or dissatisfaction after accounting for other trauma sequelae. Social support attenuated the relationship between depression and membership in the Disability and Dissatisfaction group. Participants who reported greater dissatisfaction than disability endorsed greater depression and mTBI frequency. Overall, PTSD and depression convey a heightened risk of both disability and life dissatisfaction, while social support may be protective.
