An economical, efficient, and environmentally friendly technology was developed for simultaneous remediation of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in soil and water. In this ...study, using pinecones powder as the precursor, the core-shell structural nitrogen-doped carbon foam loaded with nano zero-valent iron (nZVI@NCF) was synthesized through Mannich reaction and high-temperature carbon reduction. The nZVI@NCF was applied as the adsorbent and catalyst to simultaneously remediate the composite pollutants of Cd (II) and naphthalene (NAP). Under the optimal conditions, the adsorption capacity of Cd (II) in water and soil were 13.9 mg·g−1 and 1.97 mg·g−1, respectively, and the adsorption process conformed to the pseudo-second-order kinetic model. The degradation rates of NAP in water (10 mg·L−1) reached almost 100% as well as it could reach 59.12% in soil (10 mg·kg−1). In addition, it was proved that the presence of NAP could compete with Cd (II) for the active sites on the surface of the material to inhibit the adsorption of Cd (II), while the co-existence of Cd (II) could improve the degradation of NAP by the nZVI@NCF/PMS system due to the nZVI-Cd bimetallic effect and the pro-oxidant effect of Cd (II) promoting the generation of ROS. The free radical quenching experiment revealed that the generated ·O2− was the main substance that mediated the redox of nZVI/Fe2+/Fe3+ to oxidative NAP during the degradation process. Furthermore, the results of the phytotoxicity test demonstrated that the nZVI@NCF/PMS system could effectively remediate the soil co-contaminated with Cd (II) and NAP as well as improve the soil environment quality. This research will provide new materials and potential technologies for the efficient treatment of the composite pollutants in the environment.
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•Core-shell structural nZVI@NCF was prepared by an economical and facile method.•The nZVI@NCF was used to simultaneously remediate the Cd-NAP composite pollutants.•The co-existence of Cd could promote the degradation of NAP in nZVI@NCF/PMS system.•A multi-step repair mechanism of environmental composite pollutants was proposed.•The nZVI@NCF/PMS system presented a low ecological risk for environment and plants.
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•CO2 and H2O adsorption on fully oxidized CeO2 and partially reduced CeO2−x were in situ studied by NAP-XPS.•CO2 adsorbs weakly on fully oxidized CeO2 while strongly adsorbs on ...partially reduced CeO2−x with carbonate formed.•H2O strongly dissociates on reduced CeO2−x with surface OH and H species formed stable up to 600 K.•Reoxidation of CeO2−x occurs by both CO2 and H2O adsorption.
Insights of CO2 and H2O activation on cerium oxide based catalysts are of great interest to many important catalytic processes, which are widely studied in model systems under ultrahigh vacuum conditions. Here, in situ near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) was used to study CO2 and H2O adsorption on fully oxidized CeO2 and partially reduced CeO2−x surfaces. It is found that CO2 only weakly interacts with the stoichiometric CeO2 but strongly adsorbs on partially reduced CeO2−x surfaces with surface carbonate formation. H2O dissociatively adsorbs reversely on the CeO2 surface with H2O exposure pressure above 1 × 10−3 mbar, while H2O strongly dissociates on the partially reduced CeO2−x surfaces. The surface dissociated OH and H species are stable on the CeO2−x surface up to 600 K. Both CO2 and H2O adsorption cause clear reoxidation of partially reduced CeO2−x. This study provides new insights into CO2 and H2O interaction with cerium oxide surfaces at near ambient pressure conditions.
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•The Bi/Cu(111) interface shows enhanced activity towards CO2 activation with the synergetic effect as compared to Cu(111)•The interfacial structure is demonstrated to be important ...for the CO2 dissociation by forming the Bi-O-Cu heterostructure.•Further formation of Cu+ induced by the defective oxygen from the decomposition of Bi oxide promotes the dissociation of CO2.
Thermocatalytic CO2 reduction reaction (CO2RR) is one of the promising strategies to mitigate CO2 emissions. Meanwhile, understanding the reduction mechanism of CO2 on the catalyst surface is imperative for advancing catalyst design and the eventual industrialization under mild conditions. In this work, the catalytic role of bismuth/copper interface towards CO2RR is elaborately investigated via a combination of near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS), ambient-pressure scanning tunneling microscopy (NAP-STM) and density function theory (DFT). It is demonstrated that the initial deposition of Bi on Cu results in the formation of Bi-Cu heterogenous structure, while the interface is buried at the thick coverage. Upon CO2 exposure, Bi is oxidized at interface due to the activation of CO2 on Cu sites and subsequent migration of oxygen to Bi, while Cu+ is induced afterwards in annealing acting as the further dissociation site. Compared with the pure Cu(111), the fraction of oxidation including both lattice and defective oxygen is significantly higher on the Bi/Cu interface, indicating the synergistic effect of Bi-Cu interface in the activation of CO2. Thus, our work clearly reveals the dissociation site evolution of the Bi-Cu bimetallic heterostructure and might promote the design of Cu-based catalysts for advancing thermocatalytic CO2RR.
•This study investigated the effects of different stages of nap on memory of faces in habitual nappers.•The sleep group exhibited significantly longer reaction times (RT) after nap.•The normalized RT ...difference was positively related with the duration of N3 sleep.•The sleep group was more conservative in the judgment of faces after nap.•A nap immediately after face learning renders the memories not readily accessible.
This study investigated the effects of diurnal nap in the recognition memory for faces in habitual nappers. Thirty volunteers with habitual midday napping (assigned as the sleep group) and 28 non-nappers (assigned as the wake group) participated in this study. Participants were instructed to memorize faces, and subsequently to perform two recognition tasks before and after nap/wakefulness, i.e., an immediate recognition and a delayed recognition. There were three experimental conditions: same faces with the same view angle (S-S condition); same faces with a different view angle (22.5°) (S-D condition); and novel faces (NF condition). A mixed repeated-measures ANOVA revealed that the sleep group exhibited significantly longer reaction times (RT) following their nap compared to those of the wake group; no significant between-group differences were observed in accuracy or sensitivity (d’). Furthermore, both groups were more conservative in the delayed recognition task compared to the immediate recognition task, but the sleep group was more conservative after their nap (vs pre-nap), reflected by the criterion (β, Ohit/Ofalse alarm). Further stepwise regression analysis revealed a positive relationship between duration of stage N3 sleep and normalized RT difference before/after nap on the S-S condition. These findings suggest that an immediate nap following face learning is associated with memory reorganization during N3 sleep in habitual nappers, rendering the memories not readily accessible.
Bacteria are inherently in a hydrated state and therefore not compatible to ultra‐high vacuum techniques such as XPS without prior sample preparation involving freeze drying or fast freezing. This ...has changed with the development of near‐ambient pressure (NAP)‐XPS, which makes it possible to characterise the bacterial surface with minimal sample preparation. This paper presents NAP‐XPS measurements of Escherichia coli under various NAP conditions: at 11 mbar in a humid environment, at 2 mbar after drying in the chamber, pre‐dried at 4 mbar, and at 1 mbar after overnight pumping at 10−4 mbar. The high‐resolution spectra of carbon, nitrogen, and oxygen are presented and found to be in general agreement with XPS measurements from freeze‐dried and fast‐frozen bacteria. However, it was found that the amount of carbon components associated with polysaccharides increases relative to aliphatic carbon during drying and increases further after overnight pumping. This implies that drying has an impact on the bacterial surface.
•CeVO4 samples with various morphologies were prepared by glycol-aided hydrothermal method.•Ce2 sample with fusiform morphology exhibited the highest photodegradation of naphthalene.•The fusiform ...morphology of Ce2 favored the separation of photoexcited carriers.•Naphthalene was directly conversed to CO2 and H2O in the photocatalytic reaction by Ce2 sample.
Various morphologies and structure properties of CeVO4 photocatalysts were prepared via ethylene glycol (EG)-aided hydrothermal method and characterized by XRD, SEM, EDX, TEM, XPS, UV–Vis diffuse reflectance, PL emission and transient photocurrent responses, respectively. The influence of EG content on morphology and structure of as-prepared samples was examined as regard the photodegradation performance of naphthalene (Nap) in natural seawater. The results showed that Ce2 (CeVO4) sample with 10 mL EG addition exhibited the highest photodegradation efficiency of Nap, because the fusiform morphology of Ce2 sample favoredthe transportation of visible light and the separation of photoexcited carriers. In addition, the possible intermediate products were detected by FTIR, 3D fluorescence and GC–MS and the results showed only one mechanism of Nap direct conversion to CO2 and H2O was include in the photocatalytic reaction by Ce2 sample. The active species were detected by ESR and trapping experiments and the results showed that ∙OH played a more significant role in the photochemical degradation. Finally, the possible photodegradation mechanism of Nap over Ce2 sample was proposed on the basis of intermediate products and the active species formed in photodegradation process, and Ce4+/Ce3+ redox centers of Ce2 sample was performed under the irradiation of visible light.
Graphene-like ZnO (g-ZnO) nanostructures (NSs) and thin films were prepared on Au(111), and their reactivities toward CO and H2 were compared with that of wurtzite ZnO (w-ZnO) (0001) single crystals. ...The interaction and reaction between CO/H2 and the different types of ZnO surfaces were studied using near-ambient-pressure scanning tunneling microscopy (NAP-STM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. The reactivity of the w-ZnO(0001) surface toward CO and H2 was found to be more prominent than those on the surfaces of g-ZnO/Au(111). CO oxidation took place primarily at the edge sites of w-ZnO(0001) and the interface between g-ZnO NSs and Au(111), while g-ZnO thin films on Au(111) appeared to be inert below 600 K. Similarly, the w-ZnO(0001) surface could dissociate H2 at 300 K, accompanied by a substantial surface reconstruction, while g-ZnO on Au(111) appeared inert for H2 activation at 300 K. DFT calculations showed that the reactivities of ZnO surfaces toward CO could be related to the formation energy of oxygen vacancy (E Ovf), which could be related to the charge transfer to lattice oxygen atoms or surface polarity.
Purpose
This study explored the relationship between naps and memory among habitual nappers in China.
Methods
Medical college students participated and were divided into 30-min, 60-min, and 90-min ...time-in-bed groups. To evaluate declarative and procedural memory performance, A–B and A–C interfering word pair and interfering finger tapping tasks were employed.
Results
Among 60 students, a significant decrease in the correct recall rate in the declarative task after having a nap was found only in the 30-min group (
p
= 0.005). After learning interference (A-C word pairs), the correct recall rate for the declarative task decreased significantly in all interference tests (
p
s < 0.001). In the procedural task, the speed of sequence A in the retests increased after having a nap in all three groups (
p
s < 0.048), with a significant decrease in accuracy only in the 30-min group (
p
= 0.042). After learning interference (sequence B) in the procedural task, the speed of sequence A increased in the 60-min group after 1 h (
p
= 0.049), and both the 60-min and 90-min groups showed increased speed after one night (
p
s < 0.022). No significant improvement in speed was found in the 30-min group (
p
s > 0.05), and this group showed the lowest accuracy for sequence A (
p
s < 0.16).
Conclusion
A habitual nap time-in-bed of 60 or 90 min had better effects on declarative and procedural memory consolidation and better memory resistance against interference in procedural memory.
A few studies have reported that nighttime sleep and daytime napping are significantly associated with sleep disorders, memory, concentration, cognitive ability, and academic performance in children. ...Moreover, sleep is identified as an important factor that has a profound effect on children’s athletic performance. If a short daytime nap is shown to benefit children involved in sports activities, this evidence could be used to improve children’s athletic performance in the afternoon. In this study, we investigated whether a short daytime nap could reduce the decline in athletic performance observed in the afternoon in children involved in basketball games. We investigated 10 elementary school-age male basketball players. The study was performed under two conditions, with and without a 20-min nap during the lunch break, and evaluation was performed under both conditions for 3 days each. The reaction and 20-m sprint times were measured after morning practice, before afternoon practice, and at the end of practice on all days. At the beginning of afternoon practice, the 20-m sprint time was significantly shorter (p<0.05) in the no-nap group (4.18±0.27 s) than in the nap group (4.24±0.24 s). In conclusion, our results suggest that a short daytime nap in children may reduce the decline in exercise performance observed in the afternoon.
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