Electromagnetic absorption properties of flowerlike cobalt composites at microwave frequencies

In this work,we report the electromagnetic absorption（EMA） properties of composites consisting of micrometersized cobalt with flowerlike architecture synthesized by a facile hydrothermal reduction method.Compared with the conventional spherical Co-paraffin composites,the flowerlike Co-paraffin composites are favorable with respect to EMA performance in the low frequency region,ascribing interfacial polarization loss and Ohmic loss to the improvement in the impedance match.

Fe-based multi-phase nanocrystalline ribbons with hierarchically flowerlike structured metal oxides after modified by Orange II for Cr^VI absorption

Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.

Fabrication of Flowerlike Supramolecular Architectures of Fullerene Derivatives Bearing a Small Nitrophenyl Substituent

Flowerlike supramolecular architectures were fabricated from fulleropyrrolidincs bearing a small para-, meta-, or ortho-nitrophenyl group. The self-assembled architectures were characterized by scanning electron micro-scopy（SEM） and X-ray diffraction（XRD）. It was found that these flowerlike architectures were assembled from na- noplatcs that formed from fundamental subunit of interdigitated lamellar bilayer structure.

A CONFORMATION STUDY OF POLYELECTROLYTE-DENDRITIC SURFACTANT COMPLEXES IN DILUTE SOLUTIONS

Three dendronized polymers from generation one to generation three have been prepared by complexing negatively charged Frechet-type dendrons with a polyanion, poly（diallydimethylammoniurn chloride） （PDADMAC）. The gaffing degree has been confirmed mainly by elemental analysis. In dilute solutions of tetrahydrofuran, static light scattering studies indicate that the first generation complex has a coil-like conformation, even more flexible than PDADMAC. The second and third generation complexes exhibit polyelectrolyte behavior. Dynamic light scattering experiments indicate that all the three complexes have almost the same hydrodynamic radius, indicating that they might own similar coil conformation. Atomic force microscopy shows the existence of disordered globules formed by one or a couple of complex coils. All these observations can be explained by the flowerlike coil conformation, which is formed by the intra-molecular association. This is totally different from the stretched chain conformation formed by covalently connected dendronized polymers. This result also explains why some ordered supramolecular structures, found in condensed state of the similar complexes, are not as perfect as those of conventional dendronized polymers.

A ZnO decorated 3D copper foam as a lithiophilic host to construct composite lithium metal anodes for Li-O_(2) batteries

Lithium metal batteries(LMBs) with a high theoretical capacity are seen as a type of the most potential energy storage system.Unfortunately,the growth of lithium dendrite,the irreversible side reactions,and the infinite volume alteration still curb the practical utilization of lithium metal anodes,resulting in low Coulombic efficiency(CE) and safety problems,etc.Herein,we synthesize a lithiophilic 3D copper foam host with uniformly distributed nano-flower-like ZnO particles(CuF/ZnO) and obtain the composite lithium metal anode containing the Li_(2)O,LiZn alloy,and pure Li by the infusion of molten Li(CuF/Li_(2)O-LiZn@Li).Benefitting from the advantages of the 3D structure of copper foam and the lithiophilicity of ZnO sites,the composite lithium metal anode can restrain the volume alternation and regulate the uniform deposition of lithium.The symmetrical cells of the composite lithium metal anode have a 1600 h long cycle life with a low polarization voltage of 15 mV,and the Coulombic efficiency can maintain about 97.8% at 1.0 mA·cm^(-2),1.0mAh·cm^(-2).

Geochronology,Geochemistry and Sr-Nd-Pb Isotopic Study of the Wulong Flower-Like Glomerophyric Diorite Porphyry(Central China):Implications for Tectonic Evolution of Eastern Qinling

The Wulong diorite porphyry displays a very unusual flower-like glomerophyric texture and is thus well-known as a gemstone type of ＂Luoyang peony stone＂ for non-geologists. Hereby, we present a comprehensive study in terms of petrography, zircon U-Pb geochronology, geochemistry and Sr-Nd-Pb isotope. The rock exposed as small-scale dykes in the field, intruding in the Archean migmatized biotite- plagioclase genesis at the southern margin of the North China Craton. It exhibits typical porphyrite texture with plagioclase and amphibole as dominant and subdominant phenocrysts, respectively. The diorite porphyry rocks contain 51 wt.%-59 wt.% SiO2, belonging to medium-K calc-alkaline rock series. They are characterized by enrichment of large ion lithophile elements （LILEs, e.g., Ba） and depletion of high field-strength elements （HFSEs, e.g., Nb, Ta, Zr and Hf）, resembling island arc magmatic rocks. They show high initial Sr isotopic ratios （0.710 7-0.715 8）, low eNd（t） values （-9.9 to -13.3） and variable initial Pb isotopic ratios （206pb/204Pb vary from 17.3 to 19.3）, similar to the coeval intermediate and mafic magmatic rocks of adjacent region. These geochemical features indicate that the Wulong diorite porphyry is likely to originate from an enriched mantle with contamination of crustal materials. Zircon U-Pb dating results reveal a magma crystallization age of 480-A3 Ma, consistent with the summit of the magmatic events of the Qinling orogenic belt and reflecting the northernmost Paleozoic magmatic activity of the belt. This may indicate the influence of northward subduction of Paleotethyan oceanic slab can extend a distance of ca. 200 km to the north and reach Luoyang-Songshan region in the East Qinling Orogen.