Capacitive deionization (CDI) is a promising water purification technology. However, the current ion adsorption capacity of CDI electrode materials is still an issue, which cannot meet the rapid ...demand of clean water from saline water. Herein, trace-Fe-enhanced removal of ions from saline water via CDI is presented. The ion adsorption capacity of CDI electrodes is up to 36.25 mg g–1 in a 500 mg L–1 NaCl media at 1.2 V together with stable regeneration property. In situ Raman and ex situ XPS measurements unravel the removal mechanism of ions from saline water, and the reinforced adsorption of ions is due to the introduction of trace Fe boosting electron transfer of electro-adsorption sites during the CDI process. This work presents a promising solution to highly efficient capacitive deionization for saline water.
The comparative catalytic activity and coke resistance are examined in carbon dioxide reforming of methane over Ni/CeO2 nanorods (NR) and nanopolyhedra (NP). The Ni/CeO2–NR catalysts display more ...excellent catalytic activity and higher coke resistance compared with the Ni/CeO2–NP. The high resolution transmission electron microscope reveals that the predominantly exposed planes are the unusually reactive {110} and {100} planes on the CeO2–NR rather than the stable {111} one on the CeO2–NP. The prepared samples were also characterized by X-ray diffraction, transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy, UV and visible Raman spectra, and oxygen temperature-programmed oxidation. The {110} and {100} planes show great superiority for the anchoring of Ni nanoparticles, which results in the existence of strong metal–support interaction effect (SMSI). The SMSI effect can be helpful to prevent sintering of Ni particles, which benefits to reduce the deactivation of catalytic activity. Besides, the oxygen vacancies and the mobility of lattice oxygen also show the morphology dependence. They can participate into the catalytic reaction and be beneficial to the activation of carbon deposition. In conclusion, the excellent catalytic activity and coke resistance of the Ni/CeO2–NR should be attributed to the SMSI effect and abundant oxygen vacancies.
In recent years, dual wavelet frames derived from a pair of refinable functions have been widely studied by many researchers. However, the requirement of the Bessel property of wavelet systems is ...always required, which is too technical and artificial. In present paper, we will relax this restriction and only require the integer translation of the wavelet functions (or refinable functions) to form Bessel sequences. For this purpose, we introduce the notion of weak dual wavelet frames. And for generality, we work under the setting of reducing subspaces of Sobolev spaces, we characterize a pair of weak dual wavelet frames, and by using this characterization, we obtain a mixed oblique extension principle for such weak dual wavelet frames.
Herein, a novel concept for the separation and recovery of heavy metal ions and salt ions from wastewater by 3D graphene-based asymmetric electrodes via capacitive deionization is presented for the ...first time. Instead of the traditional practice to adsorb heavy metals via the stirring method, we rationally design functional 3D graphene by grafting ethylenediamine triacetic acid (EDTA) and 3-aminopropyltriethoxysilane on the 3D graphene surface, and take advantage of capacitive deionization for wastewater treatment. In this process, Pb 2+ is adsorbed by EDTA through chelation reaction and Na + is adsorbed into the 3D graphene pores by electrosorption. Meanwhile, 3D graphene aminated with 3-aminopropyltriethoxysilane is used as an anode to minimize the co-ion effects and improve the removal efficiency. This research investigates the adsorption and desorption behaviors of Pb 2+ and Na + and the influence of operation conditions, such as pH, voltage, concentration and time on Pb 2+ and Na + removal. The removal efficiency is 99.9% at pH 6.0 for Pb 2+ and 98.7% for Na + . It is worth noting that Pb 2+ and Na + can be separated and recovered in the desorption process in two steps due to the different adsorption mechanisms of Pb 2+ and Na + . The desorption rates are ∼99.6% for Pb 2+ and ∼97.2% for Na + , which remain at ∼94.3% and ∼88.2%, respectively, without further degradation after 8 cycles. Overall, CDI with 3D graphene-based asymmetric electrodes is a promising route for the separation and recovery of heavy metals and salt ions from wastewater.
Currently, selective catalytic reduction (SCR) of NOx with NH3 in the presence of SO2 by using vanadium-free catalysts is still an important issue for the removal of NOx for stationary sources. ...Developing high-performance catalysts for NOx reduction in the presence of SO2 is a significant challenge. In this work, a series of Fe2O3-promoted halloysite-supported CeO2–WO3 catalysts were synthesized by a molten salt treatment followed by the impregnation method and demonstrated improved NOx reduction in the presence of SO2. The obtained catalyst exhibits superior catalytic activity, high N2 selectivity over a wide temperature range from 270 to 420 °C, and excellent sulfur-poisoning resistance. It has been demonstrated that the Fe2O3-promoted halloysite-supported CeO2–WO3 catalyst increased the ratio of Ce3+ and the amount of surface oxygen vacancies and enhanced the interaction between active components. Moreover, the SCR reaction mechanism of the obtained catalyst was studied using in situ diffuse reflectance infrared Fourier transform spectroscopy. It can be inferred that the number of Brønsted acid sites is significantly increased, and more active species could be produced by Fe2O3 promotion. Furthermore, in the presence of SO2, the Fe2O3-promoted halloysite-supported CeO2–WO3 catalyst can effectively prevent the irreversible bonding of SO2 with the active components, making the catalyst exhibit desirable sulfur resistance. The work paves the way for the development of high-performance SCR catalysts with improved NOx reduction in the presence of SO2.
Phytolith remains of rice (Oryza sativa L.) recovered from the Shangshan site in the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation. However, ...because of the poor preservation of macroplant fossils, many radiocarbon dates were derived from undifferentiated organic materials in pottery sherds. These materials remain a source of debate because of potential contamination by old carbon. Direct dating of the rice remains might serve to clarify their age. Here, we first validate the reliability of phytolith dating in the study region through a comparison with dates obtained from other material from the same layer or context. Our phytolith data indicate that rice remains retrieved from early stages of the Shangshan and Hehuashan sites have ages of approximately 9,400 and 9,000 calibrated years before the present, respectively. The morphology of rice bulliform phytoliths indicates they are closer to modern domesticated species than to wild species, suggesting that rice domestication may have begun at Shangshan during the beginning of the Holocene.
The purpose of the present study was to investigate the protective effects and the underlying mechanisms of Danshensu on liver injury induced by iron overload. The mouse model was induced by ...injection of iron dextran intraperitoneally for 14 d. Danshensu significantly ameliorated liver injury by decreasing iron accumulation in the liver, possibly by down-regulating the expression of iron uptake-related proteins: divalent metal ion transporters-1 (DMT-1), transferrin receptor (TfR), and L-type calcium channel α1C subunit. Furthermore, Danshensu alleviated oxidative stress injury through potentiating glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities; Immunohistochemistry results demonstrated that Danshensu reduced the expression of inflammatory cytokines: interleukin-6 (IL-6) and transforming growth factor-beta (TGF-β). Moreover, Danshensu prominently inhibited hepatocyte apoptosis through decreasing Bax and Caspase-3 and increasing Bcl-2 expression levels. The present results suggest that Danshensu possess significant hepatic-protection at least partly through inhibition of iron uptake, oxidative stress, inflammatory, and apoptosis. Therefore, we believe that Danshensu could be used as a promising therapeutic agent for preventing and treating iron overload diseases.
Graphene-coated hollow mesoporous carbon spheres (GHMCSs) are rationally designed and originally used as efficient electrode materials for capacitive deionization. The GHMCSs are fabricated by a ...simple template-directed method using phenolic polymer coated polystyrene spheres as templates. The resulting graphene-based composites have a hierarchically porous nanostructure with hollow mesoporous carbon spheres uniformly embedded in the graphene sheets. The hierarchically porous structure of GHMCS electrodes can guarantee fast transport of salt ions, and the improved specific surface area of GHMCSs provides more adsorption sites for the formation of an electrical double layer. In addition, the graphene sheets in the GHMCSs as the interconnected conductive networks lead to fast charge transfer. The unique GHMCS structure exhibits enhanced electrochemical performance with high specific capacitance, low inner resistance and long cycling lifetime. Besides, a remarkable capacitive deionization behavior of GHMCSs with low energy consumption is obtained in a NaCl solution. The proposed carbon composite architectures are expected to lay the foundation for the design and fabrication of high-performance electrodes in the field of energy and electrochemistry.
Image-guided combined chemo-thermal therapy assists in optimizing treatment time, enhancing therapeutic efficiency, and circumventing side effects. In the present study, we developed a ...chemo-photothermal theranostic platform based on polydopamine (PDA)-coated gold nanorods (GNRs). The PDA coating was thin; however, it significantly suppressed the cytotoxicity of the cetyltrimethylammonium bromide template and allowed high cisplatin loading efficiency, arginine-glycine-aspartic acid (RGD) peptide (c(RGDyC)) conjugation, and chelator-free iodine-125 labeling (RGD-125IPt-PDA@GNRs). While loaded cisplatin was released in a pH-sensitive manner, labeled 125I was outstandingly stable under biological conditions. RGD-125IPt-PDA@GNRs had a high specificity for αvβ3 integrin, and consequently, they could selectively accumulate in tumors, as revealed by single photon emission computed tomography/CT imaging, and in target tumor angiogenic vessels, as shown by high-resolution photoacoustic imaging. As RGD-125IPt-PDA@GNRs targets tumor angiogenesis, it is a highly potent tumor therapy. Combined chemo-photothermal therapy with probes could thoroughly ablate tumors and inhibit tumor relapse via a synergistic antitumor effect. Our studies demonstrated that RGD-125IPt-PDA@GNRs is a robust platform for image-guided, chemo-thermal tumor therapy with outstanding synergistic tumor killing and relapse inhibition effects.
The origin of millet from Neolithic China has generally been accepted, but it remains unknown whether common millet (Panicum miliaceum) or foxtail millet (Setaria italica) was the first species ...domesticated. Nor do we know the timing of their domestication and their routes of dispersal. Here, we report the discovery of husk phytoliths and biomolecular components identifiable solely as common millet from newly excavated storage pits at the Neolithic Cishan site, China, dated to between ca. 10,300 and ca. 8,700 calibrated years before present (cal yr BP). After ca. 8,700 cal yr BP, the grain crops began to contain a small quantity of foxtail millet. Our research reveals that the common millet was the earliest dry farming crop in East Asia, which is probably attributed to its excellent resistance to drought.
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