Novel Three-Dimensional Graphene-Like Networks Loaded with Fe3O4 Nanoparticles for Efficient Microwave Absorption.

A novel three-dimensional graphene-like networks material (3D-GLN) exhibiting the hierarchical porous structure was fabricated with a large-scale preparation method by employing an ion exchange resin as a carbon precursor. 3D-GLN was first studied as the effective microwave absorbing material. As indicated from the results of the electromagnetic parameter tests, and the minimum reflection loss (RL) of the 3D-GLN reached -34.75 dB at the frequency of 11.7 GHz. To enhance the absorption performance of the nonmagnetic 3D-GLN, the magnetic Fe3O4 nanoparticles were loaded on the surface of the 3D-GLN by using the hydrothermal method to develop the 3D-GLN/Fe3O4 hybrid. The hybrid exhibited the prominent absorbing properties. Under the matching thickness of 3.0 mm, the minimum RL value of hybrid reached -46.8 dB at 11.8 GHz. In addition, under the thickness range of 2.0-5.5 mm, the effective absorption bandwidth (RL < 10 dB) was 13.0 GHz, which covered part of the C-band and the entire X-band, as well as the entire Ku-band. The significant microwave absorption could be attributed to the special 3D network structure exhibited by the hybrid and the synergistic effect exerted by the graphene and the Fe3O4 nanoparticles. As revealed from the results, the 3D-GLN/Fe3O4 hybrid could be a novel microwave absorber with promising applications.

Size-controlled Ag quantum dots decorated on binder-free hierarchical NiCoP films by magnetron sputtering to boost electrochemical performance for supercapacitors.

This paper reports novel binder-free and self-supported electrodes of hierarchical nickel-cobalt phosphide (NiCoP) films decorated with size-controlled Ag quantum dots by magnetron sputtering (Ag/NiCoP). Ag quantum dots with an average particle size of 7.90 nm uniformly distribute over the nanosheet-assembled architecture of NiCoP films. Benefitting from the good ohmic contact in the interfaces between Ag quantum dots and NiCoP nanosheets, Ag/NiCoP exhibits an ultrahigh specific capacitance of 6150 mF cm-2 (3050 F g-1 at 1 A g-1) higher than the 3445 mF cm-2 (1722 F g-1 at 1 A g-1) of bare NiCoP at 2 mA cm-2. The specific areal capacitance has been increased by 78.5% after introducing Ag quantum dots. 34% capacitance retention rate is achieved while the current density increases from 2 to 30 mA cm-2. The cycling stability displays a remarkable capacitance retention of 73% for 4000 cycles at 30 mA cm-2. These boosted electrochemical performances are mainly attributed to the synergistic effects of enough electroactive sites, high electronic conductivity, and easy electrolyte ion diffusion. An asymmetric supercapacitor is fabricated using hierarchical Ag/NiCoP as the positive electrode and activated carbon as the negative electrode. The supercapacitor delivers an energy density of 0.254 mW h cm-2 (1.81 mW h cm-3) at a power density of 1.88 mW cm-2 (13.4 mW cm-3). At a power density of 18.8 mW cm-2 (134 mW cm-3), an energy density of 0.115 mW h cm-2 (0.82 mW h cm-3) can still be maintained. This study provides an avenue to design a novel generation of supercapacitors for energy storage devices.

Enhanced magnetostriction derived from magnetic single domain structures in cluster-assembled SmCo films.

Cluster-assembled SmCo alloy films were prepared by low energy cluster beam deposition. The structure, magnetic domain, magnetization, and magnetostriction of the films were characterized. It is shown that the as-prepared films are assembled in compact and uniformly distributed spherical cluster nanoparticles, most of which, after vacuum in situ annealing at 700 K, aggregated to form cluster islands. These cluster islands result in transformations from superparamagnetic states to magnetic single domain (MSD) states in the films. Such MSD structures contribute to the enhanced magnetostrictive behaviors with a saturation magnetostrictive coefficient of 160 × 10-6 in comparison to 105 × 10-6 for the as-prepared films. This work demonstrates candidate materials that could be applied in nano-electro-mechanical systems, low power information storage, and weak magnetic detecting devices.

The expression and distributions of ANP32A in the developing brain.

Acidic (leucine-rich) nuclear phosphoprotein 32 family, member A (ANP32A), has multiple functions involved in neuritogenesis, transcriptional regulation, and apoptosis. However, whether ANP32A has an effect on the mammalian developing brain is still in question. In this study, it was shown that brain was the organ that expressed the most abundant ANP32A by human multiple tissue expression (MTE) array. The distribution of ANP32A in the different adult brain areas was diverse dramatically, with high expression in cerebellum, temporal lobe, and cerebral cortex and with low expression in pons, medulla oblongata, and spinal cord. The expression of ANP32A was higher in the adult brain than in the fetal brain of not only humans but also mice in a time-dependent manner. ANP32A signals were dispersed accordantly in embryonic mouse brain. However, ANP32A was abundant in the granular layer of the cerebellum and the cerebral cortex when the mice were growing up, as well as in the Purkinje cells of the cerebellum. The variation of expression levels and distribution of ANP32A in the developing brain would imply that ANP32A may play an important role in mammalian brain development, especially in the differentiation and function of neurons in the cerebellum and the cerebral cortex.

[Expression and significance of c-Jun activation domain binding protein 1 in human colorectal carcinoma].

OBJECTIVE: To explore the association of Jab1 (c-Jun activation domain binding protein 1) expression during carcinogenesis and clinicopathological characteristics of colorectal carcinoma (CRC) . METHODS: Tissue specimens were obtained from 80 cases of CRC from January 2007 to December 2008. And the expression of Jab1 protein for each specimen was detected by immunohistochemistry (EnVision). Six representative paired samples of cancerous and paired adjacent normal tissues were collected for Western blot. The relationships between the expression level of Jab1 protein and the clinicopathological characteristics of primary CRC were retrospectively analyzed. RESULTS: A high-level expression of Jab1 was present in cancerous tissues but not in paired adjacent normal tissues. The positive expression rate of Jab1 protein was as high as 96.3% (77/80) . And its high expression rate was 82.5% (66/80) , low expression rate 17.5% (14/80) and 8.8% (7/80) in cancerous and paired adjacent normal tissues respectively (P < 0.05) . Its expression was correlated with differentiation, invasion depth, TNM stage and lymph node metastasis (all P < 0.05) . Jab1 was significantly correlated with Ki-67 (r = 0.548, P < 0.01) and inversely with p27(kip1) (r = -0.461, P < 0.01). CONCLUSIONS: An over-expression of Jab1 protein might play an important role in the pathogenesis of CRC. Thus it may become a novel diagnostic marker and a therapeutic target in patients with CRC.

Structure and luminescence properties of eu3+-doped cubic mesoporous silica thin films.

Eu3+ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol-gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu3+ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of5D0-7F1 and 5D0-7F2 of Eu3+ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu3+ ions-doped mesoporous silica thin films increases linearly with increasing Eu3+ concentration.

Structure and optical properties of ordered mesoporous titania-silica composite thin films.

Highly ordered mesoporous titania-silica (TiO2-SiO2) composite thin films have been prepared by spin-coating technique using poly(alkaline oxide) triblock copolymers EO20PO70EO20 (P123) as structure-directing agent. Low-angle X-ray diffraction analysis shows that the mesoporous composite thin films remain a long range periodic ordered structure even if the TiO2/SiO2 ratio in the thin films is as high as 80%. Wide-angle X-ray diffraction analysis reveals that the average grain size of TiO2 increases from 2.2 to 5.1 nm as the TiO2/SiO2 ratio increases from 20% to 80%. The crystal structure of TiO2 is identified to be the anatase phase. Transmission electron microscopy observations confirm that the mesoporous titania-silica composite thin films have a hexagonally ordered pore array nanostructure. Ultraviolet-visible absorption spectra give the evidence that the TiO2 nanocrystals as well as the four-coordinate Ti co-exist in the silica matrix. The semiconductor TiO2 nanocrystals in the silica matrix have an obvious blue shift phenomenon of the absorption edge. As the average TiO2 grain size increases from 2.2 to 5.1 nm, the band gap of the TiO2 nanocrystals in the mesoporous titania-silica composite thin films decreases from 3.9 to 3.45 eV.

Structure and Photoluminescent Properties of ZnO Encapsulated in Mesoporous Silica SBA-15 Fabricated by Two-Solvent Strategy.

The two-solvent method was employed to prepare ZnO encapsulated in mesoporous silica (ZnO/SBA-15). The prepared ZnO/SBA-15 samples have been studied by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption isotherm, and photoluminescence spectroscopy. The ZnO/SBA-15 nanocomposite has the ordered hexagonal mesostructure of SBA-15. ZnO clusters of a high loading are distributed in the channels of SBA-15. Photoluminescence spectra show the UV emission band around 368 nm, the violet emission around 420 nm, and the blue emission around 457 nm. The UV emission is attributed to band-edge emission of ZnO. The violet emission results from the oxygen vacancies on the ZnO-SiO(2) interface traps. The blue emission is from the oxygen vacancies or interstitial zinc ions of ZnO. The UV emission and blue emission show a blue-shift phenomenon due to quantum-confinement-induced energy gap enhancement of ZnO clusters. The ZnO clusters encapsulated in SBA-15 can be used as light-emitting diodes and ultraviolet nanolasers.