Electromagnetic functional ceramics added iron tailings were prepared using the burning method, and the EMWA properties were tested through the arch testing method at 2–18 GHz. It was found that the minimum reflection loss (RL) peak was −16.0 dB at 17.0 GHz, and that the thickness of ceramics was 2.00 cm. With the thickness increasing, the RL value went up, and the RL peak number also increased. The magnetic and dielectric losses of tailing powders acting as an absorbent were the main mechanisms of EMWA properties for ceramics, which could be used for electromagnetic radiation protection of architectural spaces.

在提升工科研究生培养能力的教育实践中,充分发挥导师对青年学生健康成长的引导作用,发掘学生的主观能动性,教授学生科学认识现实社会与科学探索未知世界的思维方法,促进学生综合能力的提高,为中华民族的伟大复兴输送高水平的创新性人才.

A convenient two-step hydrothermal method was developed to synthesize water dispersible NaTaO3 nanoparticles. The growth of the NaTaO3 nanoparticles was retarded with the aid of a water soluble complex agent in the first step, such as citric acid, bicine, triacetin, and EDTA 2Na, which formed complexes with Ta5+. The sizes of the NaTaO3 nanoparticles, ranging from 5 nm to 30 nm, could be tuned by adjusting the reaction time as well as the complexing agent. An ultraviolet photodetector was fabricated with the solution processed NaTaO3 film as the active layer, which presented a sensitive response to 280 nm deep UV illumination with a light to dark current ratio of about 160 and a response time of about 50 ms.

Polyalcohol is one of the important medium temperature phase change materials (PCMs) for thermal energy storage, in which liquid-free solid-solid PCMs are more promising although sublimation can hardly be avoided when crystals transform to the "plastic phase". We reported here the preparation of encapsulated Tris(hydroxymethyl)methyl aminomethane (Tris) with the SiO2 shell by sol-gel process. Through the hydrolysis and polycondensation of the bicomponent silicon precursors mixed with tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTS) of proper ratio, Tris@SiO2 microcapsules with excellent sealing property can be obtained, which prevent the leakage of Tris outside the capsules. Besides, silica encapsulation doubles the thermal conductivity of the PCMs to 0.478 W/(m K). The DSC measurement shows that the Tris@SiO2 capsule owns a reversible phase change in the range of 110-155 degrees C, which will stabilize at about 146 J/g during 70 times of thermal cycling. The Tris@SiO2 capsules have good potential for medium temperature thermal energy storage applications. (C) 2015 Elsevier Ltd. All rights reserved.

Wide bandgap NaTaO3 nanocrystals (NaTaO3 NCs) were synthesized by a two-step hydrothermal method. The hybrid film based on the pyridine modified NaTaO3 NCs and 1, 3, 5-tri(m-pyrid-3-yl-phenyl) benzene (TmPyPB) was prepared by solution processing at room temperature. Photodetector based on the hybrid film presented selective sensitivity to UV signals with wavelength shorter than 317 nm because the bandgap wider than 4.0 eV. Under 5 mW/cm(2) 280 nm illumination through the semi-transparent Al cathode, a high ultraviolet signal-to-noise ratio of 3 orders of magnitude with response time about 200-300 ms can be achieved for the device in the case of -3 V bias. (C) 2015 Elsevier B.V. All rights reserved.

Stable aqueous amino-grafted silicon nanoparticles (SiNPs-NH2) were prepared via one-pot solution method. By grafting amino groups on the particle surface, the dispersion of SiNPs in water became very stable and clear aqueous solutions could be obtained. By incorporating SiNPs-NH2 into the hole transport layer of poly(3,4-ethylenedioxythiophene)/polystyrene sulfonic acid (PEDOT:PSS), the performance of polymer solar cells composed of poly[2-methoxy,5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as active layer can be improved. SiNPs-NH2 are dispersed uniformly in the PEDOT:PSS solution and help form morphologies with small-sized domains in the PEDOT:PSS film. SiNPs-NH2 serve as screens between conducting polymer PEDOT and ionomer PSS to improve the phase separation and charge transport of the hole transport layer. As a result, the sheet resistance of PEDOT:PSS thin films is decreased from (93 ± 5) × 105 to (13 ± 3) × 105 Ω/□. The power conversion efficiency (PCE) of polymer solar cells was thus improved by 9.8% for devices fabricated with PEDOT:PSS containing 1 wt% of SiNPs-NH2, compared with the devices fabricated by original PEDOT:PSS.

One-dimensional crystals of fluorinated perylene diimides were achieved by the self-assembly of them via solvent-nonsolvent exchanging. The π-conjugated fluorinated perylene diimides were assembled into highly-ordered nanostructures of well-defined morphologies in organic solvents due to the π-π interaction between the aromatic cores. It was found that with more introduced F atoms, perylene diimides showed remarkably improved solubility and thus were much easier to grow into crystals, due to the increased polarity induced by the strong electron-withdrawing F group. More importantly, single crystal of N,N′-diperfluorophenyl-3,4,9,10-perylenetetracarboxylic diimide(DPFPP) was obtained, and the unit cell-dimensions of triclinic structure were determined by the selected area electron diffraction( SAED) patterns to be a=0.712 nm, b=1.072 nm, c=2.914 nm, α=97.0°, β=89.6°, γ=93.4°. Owing to most of the longest c-axis orienting nearly vertically to the long axis of the needle crystal, the molecular planes are expected to be vertical to the needle axis.

Mannitol@Silica core-shell capsules were prepared from W/O emulsion by adding silicon precursor into the oil-continuous phase to form silica shell through interfacial polymerization reaction. The bicomponent mixture of tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTS) was used as silicon precursor to form relatively thick silica shell. The reaction was triggered by the penetration of APT'S from oil-continuous phase into the aqueous phase and the silica shell formed as both TEOS and APTS hydrolyzed and polymerized after diffusing through the W/O interface. The growth of the shell layer was believed to be an outside-in mode. The mannitol crystal was well sealed inside the silica capsule under an optimized condition and the leakage was successfully avoided. The Mannitol@Silica core-shell capsules own irreversible phase change character in the range of 142.1-166.2 degrees C with latent heat of 147.4J/g. (C) 2014 Elsevier B.V. All rights reserved.

In this work, we study the correlation of corrosion resistance, characterization of related oxide layer and microstructure mainly using thermohydrogen processing (THP) plus common industrial heat treatment of Ti-6Al-4V alloy. It appears that better corrosion resistance and higher hardness of Ti-6Al-4V alloy can be achieved by post-THP annealing treatment associated with controlled oxidation reaction at 704°C which leads to formation of significant thinner and denser oxide layer with increased amount of TiO2, Al2O3, and V2O5.

Chromatic organic pigment-SiO2 composite particles with six different colors (CYM and RGB) were prepared by a modified sol-gel method. With the aid of a cationic polyelectrolyte, poly(diallyldimethylammoniumchloride), amorphous silica was coated onto the surface of organic pigments which was revealed by the variation of the zeta potential and average particle size, together with TEM images and EDX and XPS results. Because of the fine scattering properties of silica to visible light, the intensity of the reflectance peak increased significantly, which makes the composite particles more vivid than the organic pigments. The chromatic electrophoretic suspension was prepared by mixing Span 85 and the composite particles anchored with a self-made block copolymer PLMA-b-PDMAEMA in tetrachloroethylene. All the colored ink particles have similar zeta potentials and mobility of about 30 mV and 4-5 x 10(-10) m(2) V-1 s(-1), respectively. White/color (CYM and RGB) dual-particle electronic ink containing PLMA-b-PDMAEMA treated pigment-SiO2 composite particles and TiO2 grafted with a polymer present excellent performance and quick response under an applied DC field of 0.15 V mu m(-1).

We have studied the effect of silicon nanocrystals (SiNCs) as a third component on performance of organic bulk heterojunction solar cells composed of poly[2-methoxy,5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend film. By adding suitable amounts of SiNCs into MEH-PPV:PCBM blend, the device performance such as external quantum efficiency, short circuit current density (J(SC)), and power conversion efficiency (PCE) improved. Incorporation of 2.5% SiNCs in the blend led to 13.6% improvement of J(SC), which in turn resulted in 18% improvement of PCE up to 2.28%. The improved performance was mainly due to the improvements both in the charge generation from the interface of MEH-PPV/SiNCs and the charge collection at the cathode.

A triarylamine-containing fluorene derivative (FP) with wide bandgap and excellent thermal stability was synthesized and used as electron donor to construct planar heterojunction organic ultraviolet sensor (UVS), while bis(4-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl)diphenylsilane (NSN) was used as electron acceptor. The UVS ITO/PEDOT:PSS/FP/NSN/LiF/Al showed sensitive visible-blind response to UV illumination from both ITO and cathode sides. When no bias applied, the peak responsivity to UV light through ITO and cathode side was 47 and 33mA/W, respectively. To the irradiation from the semitransparent Al side, the most sensitive response range covers the UVB region. Under a bias of −4V, the peak responsivity at 300nm reaches 473mA/W.

Electrophoretic displays (EPDs) are attracting a great deal of academic and commercial interest due to the advantages of both electronic displays and conventional paper. The key materials for EPD application of microcapsules are the electrophoretic particles and the capsule wall enwrapping the electrophoretic suspension inside. Here, black and white electrophoretic particles with low density and good dispersity such as titanium dioxide, carbon black, and Cu2Cr2O3 were prepared by surface modification of the pigments. The preparation and properties of the gelatin-based microcapsules prepared by complex coacervation methods are also summarized. The microcapsules have transparent and elastic walls of compact structure, which endows them with good barrier properties and thermal stability for EPD application. EPD prototype devices based on the obtained microcapsules were prepared and could be driven at 9 V.

A triphenylbenzene-containing carbazole derivative (PCP) with wide bandgap, good hole mobility, and excellent thermal stability was synthesized and used as electron donor to construct planar heterojunction organic ultraviolet sensors (UVSs), while bis(4-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl)diphenylsilane (NSN) was used as electron acceptor. The UVS ITO/PEDOT:PSS/PCP/NSN/LiF/Al/Ag showed good responses to illumination from both ITO and cathode sides. When a semitransparent cathode was applied, the response region could be further extended to deep-ultraviolet (DUV) region. When the semitransparent Al (9nm)/Ag (30nm) cathode was replaced by Al (13nm), the blue-shift of the response spectra of the UVS could be found. It was especially interesting that the cutoff of response could be changed by using different kind of cathodes. This study may provide a useful guideline to achieve low-cost organic deep-ultraviolet sensors (DUVSs) with tunable spectral response.

The design of the oppositely charged ink particles based on titanium dioxide and carbon black for the monochrome electrophoretic display (EPD) was reported. The white ink particles with acidic surface and black ink particles with basic surface were synthesized and sterically stabilized by long alkyl chains, which were charged oppositely by mixing with basic surfactant (OLOA 1200) and acidic surfactant (Span 80), respectively. The electrophoretic mobility and the Zeta potential were -3.87×10(-10)m(2)V(-1)s(-1) and -25.1 mV for the white ink particles, 3.79×10(-10)m(2)V(-1)s(-1) and 24.6 mV for the black ink particles. In addition, the block copolymer, poly(lauryl methacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate) (PLMA-b-PDMAEMA) synthesized by atom transfer radical polymerization (ATRP), was first incorporated in the modification of the pigments for the fine encapsulation. Then, a stable dual-particle electronic ink with contrast ratio of 120:1 was prepared and encapsulated with the gelatin (GE)/sodium carboxymethylcellulose (NaCMC)/sodium dodecyl sulfate (SDS) microcapsules by complex coacervation method. Finally, the matrix character display prototype driven at a low voltage exhibited excellent performance, the contrast ratio of which was 8:1 at 9 V DC.