Three series of europium(Ⅲ) ion-doped tungstates red phosphors were prepared by the high temperature solid-state reaction method. Their photo-luminescent properties were investigated at room temperature. The results indicate that the phosphors show intensely red emission under 395 and 465 nm light excitation, matching with the light-emitting wavelength of a near-UV-emitting InGaN chip and a blue-emitting InGaN chip, respectively. Therefore the tungstates phosphors can be applied as an efficient red component for NUV InGaN-based and blue InGaN- based white LEDs. No concentration quenching of Eu³⁺ in Ca₉Eu₂W₄O₂₄ and Sr₉Eu₂W₄O₂₄ is observed, while the quenching concentration of Eu³⁺ in Ca₃La₂W₂O₁₂ is about 40%. Finally the related LEDs are fabricated with Ca₉Eu₂W₄O₂₄, Sr₉Eu₂W₄O₂₄ and Ca₃La_1.2Eu_0.8W₂O₁₂, and the performances of these LEDs are discussed to analyze the advantage and deficiency of such tungstates phosphors in applications for WLEDs.

Using NH₄HCO₃-NH₃·H₂O as a mixed precipitator, CaMoO₄：Eu³⁺ red phosphor was successfully synthesized by chemical co-precipitation method. The processes of thermal decomposition and phase formation for CaMoO₄：Eu³⁺ precursor were analyzed by TG-DTA and XRD. Compared with solid-state method, both surface morphology and luminescence properties of CaMoO₄：Eu³⁺ red phosphor using precipitators NH₄HCO₃, NH₃·H₂O and NH₄HCO₃-NH₃·H₂O are evaluated by means of SEM and PL respectively. After calcination at 700℃, the precursor is completely converted to a single scheelite structure of CaMoO₄：Eu³⁺. Photoluminescence intensity of the phosphor reaches the maximum value at 900℃. The phosphor prepared by using mixed precipitator is uniform spherical particle, and has no aggregation with average size of 0.9μm. Compared with solid-state method, the Eu-O CTS of the red phosphor slightly shifts toward long wavelength. The strong electron absorbability of ⁷F₀→⁵L₆ (394nm) and ⁷F₀→⁵D₂ (465nm) effectively improves the performance of red phosphor. In addition, the photoluminescent intensity from the mixed precipitation is increased to 2 times of that of the red phosphors prepared by solid-state method.

Lu_xY_1-xAlO₃：Ce single crystal samples were prepared by the Czochralski method. By adopting micropolariscope, field emission stereoscan, electron probe and thermal stress analysis, the macroscopic defects in Lu_xY_1-xAlO₃：Ce single crystals such as split, iridium inclusion, gas hole, gas cavity, twin, cleavage were investigated. It is supposed that, in the crystals of different shapes, the direction of the composite force of thermal stress varies, thus resulting in the different orientations of cracked section. Factors including enhancing heat preservation, installing a suitable temperature field in accordance with crystal shapes may contribute to the acquisition of perfect Lu_xY_1-xAlO₃：Ce single crystals. High temperature melt erodes iridium crucibles, and the microcontent oxygen in protective atmosphere oxidizes iridium crucibles, thus resulting in the iridium inclusions in Lu_xY_1-xAlO₃：Cesingle crystals. Decreasing oxygen content in the furnace, pressure die casting iridium crucibles using iridium of high purity and other factors may help reduce iridium inclusions. With increasing melt temperature moderately to decrease its viscosity and air pressure in the furnace, gas inclusions decrease. The cell parameters a and b are very close in Lu_xY_1-xAlO₃：Ce single crystals with low Lutetium content, and the adjacent cell parameters interchange with the inducement of stress, thus leading to twining along <110> direction.

High optical quality 0.2at% Fe doped YAP and 0.5at% Cu doped YAP single crystals were grown successfully by Czochralski method respectively. The separation coefficients of Fe ion in 0.2at% Fe doped YAP and Cu ion in 0.5at% Cu doped YAP crystals determined by ICP-AES method were 0.13 and 0.28 respectively. The absorption spectra and X-ray excitation luminescence spectra of the Fe:YAP and Cu:YAP crystals annealed in reduction/oxidation atmosphere were measured at room temperature. Microcosmic mechanisms of the spectra characteristics and the effects of anneal on crystals were analyzed. Finally, the thermoluminescence spectra of Fe:YAP and Cu:YAP crystals were also studied. It is found that Cu:YAP crystal is a prospective dosimetry material.

Zinc germanium phosphide crystals about 20mm×90mm were grown by using Bridgman techniques. The three measured crystal sheets with thickness 4.0mm were obtained from the tail, middle and top of single crystal ingot. The infrared absorption properties were studied according to the experimental and theoretical data. The results show that the transmitted intensity gradually increased from top to bottom of ZGP crystals, which is caused by the inhomogeneous distribution of different kinds of intrinsic point defect. The absorption spectra of donor defects and acceptor defect  in ZGP crystals are calculated theoretically. It is found that the influence of acceptor defect  on absorption spectra is stronger than that of donor defect.

The zinc oxide nano-materials with three structures including 30?80nm spherical, length of 350nm rod and thickness of 50nm flake were synthesised at different volume ratio of water and oil phase (R) by the reverse phase microemulsion which consist of surfactant JFC, 1-octanol, cyclohexane and aqueous solution. The microstructures of zinc oxide nano-materials were observed by XRD, SEM, and HRTEM. The results show that the dimensions of zinc oxide nano materials are controlled by the shape of water core, and their crystal structures are controlled by the dynamic exchange of reactants between water cores and ZnO anisotropic growth in aqueous solution. Because the microemulsion conductivity is closely related to the water core shape, different morphology of zinc oxide nano-materials can be synthesized by adjusting conductivity. In addition, the photocatalytic properties of the different dimensions ZnO were evaluated with methyl orange aqueous solution as simulate pollutant. The result show that 1-D nano-ZnO has higher photocatalytic activity than 0-D and 2-D nano-ZnO materials.

The molecular sieve catalysis material of Si-MCM-41, Sn-MCM-41 were preparaed under the condition of low template concentration in weak base and the samples were characterized by XRD, N₂ adsorption-desorption, FT-IR, ICP-AES and TEM techniques. Effect of the synthesis methods on the Sn-containing MCM-41 were studied. The results showed that Sn species were mainly incorporated into the framework of MCM-41 molecular sieves prepared by direct hydrothermal synthesis method (DHT), while Sn species were mainly existed on the wall surface of Sn-MCM-41 molecular sieves prepared by template-ion exchange method (TIE). The catalytic properties of Sn containing MCM-41 molecular sieves in Baeyer-Villiger oxidation of cyclohexanone were investigated. Catalytic activity results show that under the reaction condition of n(H₂O₂):n(Cyclohexanone)＝3:1, 30 g dioxane, at 70℃ for 6 h, the conversion of cyclohexanone and the selectivity of ε-caprolactone reach 40.02% and 45.69%, respectively.

Copper-doped silica membranes were prepared via Sol-Gel process with tetraethylorthosilicate(TEOS) and copper nitrate as precursors. The status of copper in the membranes was detected by means of FT-IR, XPS, XRD and the pore structure was determined by N₂ adsorption. The effects of copper dopant and H₂O/TEOS molar ratio on the pore structure were investigated and the stability of the pore structure under hydrothermal conditions was studied in detail. The results show that when the molar ratio of TEOS to H₂O is 0.5, it leads to microporous structure, with a pore volume of 0.155 cm³/g and a sharp pore size distribution centered at 0.5nm for the sample with a Cu/Si molar ratio of 0.8. A faction of copper is incorporated into silica framework by replacing silicon atoms, and the residual mainly exists as crystalline phase such as Cu and Cu₂O outside the framework. The microporous structure of the doped samples could be preserved for a short time (240h) under hydrothermal conditions but finally collapsed after further hydrothermal treatment.

Lead-free glass in SnO-CaO-P₂O₅ ternary system were fabricated by melt quenching method. The glass-forming region, coefficient of thermal expansion (CTE), volume resistivity as well as chemical durability of the glass were investigated by the methods of X-ray diffractometer, thermal expansion instrument, insulation resistance instrument, and grain mass loss method. The results show that the glass-forming region is larger than that of SnO-ZnO-P₂O₅ ternary system. The minimum content of P₂O₅ to form glass phase should be 25mol%, while it increases rapidly to about 40mol% with the increase of CaO amount. Softening temperature (about 445℃) and CTE (9.0×10?6-10.0×10^-6/℃) of the glass are equivalent with those of Pb-based sealing glass. The volume resistivity presents a maximum at about 50mol% P₂O₅ content with the increase of P₂O₅ amount, while it decreases with the increase of SnO amount. Research on the samples of 10SnO-40CaO-50P₂O₅-xSiO₂ system show that with the increase of SiO₂ amount, the CTE decreases from 9.8×10^-6/℃ to 7.6×10^-6/℃ and the volume resistivity increases gradually, while the mass loss decreases gradually in acid and neutral condition and increases in basic condition.

It is research focus that composite materials including glass and skeletal structure are used as sealant in solid oxide fuel cell (SOFC). The composite sealant with 10wt%-30wt% ZrO₂-filler in the Bi₂O₃-BaO-SiO₂(BiBaSi) glass were researched in order to improve sealing properties at high temperature. As a result, the coefficients of thermal expansion of the composite sealants were increased than that of basic glass. The suitable sealing temperatures of composite sealant vary from the 720℃ of base glass to 780℃, 860℃ and 900℃ of BiBaSi-10Zr, BiBaSi-20Zr, BiBaSi-30Zr, respectively. ZrO₂-fillers in base glass have two roles: Parts of ZrO₂-fillers as skeletal structure materials always exist in base glass, which help to maintain the required shape and size of sealant. The other ZrO₂-fillers can also drop into the network of the BiBaSi glass and therefore form a new phase Bi₄Si₃O₁₂. Two kinds of crystal phase of ZrO₂ and Bi₄Si₃O₁₂ coexist in the composite sealant to improve the stability of composite system in high temperature. The properties of sealing materials could be easily controlled in SOFC sealant by changing the amount of ZrO₂-fillers in composite materials.

The nanoparticles of Al(NO₃)₃-Zr(NO₃)₄ as the precursor of nano Al₂O₃-ZrO₂ particulates were prepared by means of supercritical fluid antisolvents (SAS) process using CO₂ as antisolvents and absolutely ethanol as solvent. The effects of temperature and pressure on the preparation process and the co-antisolvent effect of Al and Zr components in the precursor were investigated. The spherical Al₂O₃-ZrO₂ nanoparticles were obtained via the calcination of Al(NO₃)₃-Zr(NO₃)₄. The nanoparticles and precursor were characterized by TG-MS, XRD, XPS, FEG-TEM and TPR. In addition, the reducing property of Al₂O₃-ZrO₂ nanoparticles supported Ni was examined. Compared with the catalyst support prepared from conventional impregnation-precipitation method, Ni could be dispersed better on the Al₂O₃-ZrO₂ nanoparticles prepared from SAS. It suggests that the nano-particulates prepared from SAS can be a promising candidate for catalyst support.

Compaction process of the functional ceramic materials were dynamically simulated by discrete element method (DEM), and the particles distribution, stress and porosity of the green compact under the actions of gravity and microgravity were also analyzed. The results showed that under the action of gravity, the distribution of different size particles was inhomogeneous, a substantial part of small size particles were found concentrated near the upper punch, while under the action of microgravity, the heterogeneity of particles was significantly reduced. Compared with microgravity condition, the distribution of stress gradients was larger under the gravity condition, and the stress near the upper and low punches was lager than that at the middle region, and the distribution gradient of the porosity was also larger.

Advanced TEM techniques were applied for studying precursor derived Si-B-C-N (T2-1) ceramics, which provided a direct view of nano-scaled microstructure evolution and nucleation. The results showed that after directly pyrolysis at 1400℃, SiC and Si3N4 nano-crystals, graphitic and BCN clusters nucleated from T2-1 amorphous matrix. In order to avoid the high temperature decomposition caused by the reaction between carbon and Si₃N₄, as well as to keep the strength of material and also improve its high temperature stability, T2-1 was also produced at relatively lower pyrolysis temperature (1000℃) for study and comparison. Different from T2-1 pyrolyzed at 1400℃, the results of microstructure show that lower pyrolysis temperature efficiently retards the crystallization of Si₃N₄, which is approved by the samples further annealed at 1400℃. Such phenomenon is believed being caused by early stage phase separation, which only provides SiC an advantage of nucleation. Thus, pyrolysis process is approved becoming one of the effective methods not only to control microstructure development, but also to improve the high-temperature stability of this material.

Based on thermodynamic analysis, (TiB₂+TiC)/Ti₃SiC₂ composite ceramics were in-situ prepared by hot-pressing with TiH₂, Si, graphite and B₄C powders as raw materials. The phase composition and microstructure of the materials were characterized by XRD, SEM and TEM. Effects of sintering temperature on phase composition, sintering performance, microstructure and mechanical properties were investigated. The results indicate that fully densified (TiB₂+TiC)/Ti₃SiC₂ composite ceramics could be obtained after sintered at 1400-1600℃. With the increase of sintering temperature, the bending strength, fracture toughness and Vickers hardness of the composite increase gradually. The materials sintered at 1500?1600℃ show optimized microstructure and consequently excellent mechanical properties, i.e., bending strength of above 700MPa, fracture toughness of above 9MPa·m^1/2 and Vickers hardness of 7.33-8.31GPa. As reinforcing agents, columnar TiB₂ grains and equiaxed TiC grains, were incorporated by in-situ reaction during hot-pressing process to increase the strength and toughness of Ti₃SiC₂ matrix dramatically by the synergistic action of the mechanisms such as particulate reinforcement, crack deflection, grain's pull-out and fine-grain toughening.

A novel crosslingking system, hydroxyapatite-D-glucono-δ-lactone (HA-GDL) was developed to prepare alginate hydrogel, in which calcium ions can be released to initiate gelation. A series of hydrogels were prepared by adjusting the sodium alginate (SA) concentration and the molar ratio of calcium ion in HA to carboxyl of SA. Gelation time, surface morphology, mechanical property and swelling capacity of hydrogels crosslinked by HA-GDL system were characterized and compared with that crosslinked by the calcium carbonate- D-glucono-δ-lactone (CaCO₃-GDL) system. The results show that under the same conditions, the hydrogels obtained from the HA-GDL system have faster gelation rate, more uniform structure, stronger mechanical strength and lower swelling ratio compared with that obtained from CaCO₃-GDL system. Chondrocytes of newborn rabbit are embedded in alginate hydrogels to construct tissue engineered cartilage in vitro. Primary results show that the alginate hydrogels prepared with HA-GDL system have good cell compatibility and are with potential to be used as a scaffold for cartilage repair.

Hierarchical polyaniline/multiwalled carbon nanotube (MWCNT) nanocables was synthesized by in-situ chemical polymerization directed by cationic surfactant cetyltrimethylammonium bromide (CTAB). Morphological and structural characteristics, gas-sensing properties, as well as thermal stability of the hybrid nanocomposites were characterized by using various techniques, including Fourier transform infrared spectroscope (FT-IR), UV-Visible absorption spectrum(UV-Vis), scanning electron microscope (SEM), transmission electronmicroscope (TEM), thermogravimetric analyzer and gas-sensing measurement. The results indicate that the as-prepared PANI/MWCNT is uniform with 20nm thick needle-like PANI shell. The sensors based on PANI/MWCNT nanocomposites and pure PANI are tested for ammonia gas. Compared with the reported PANI/MWCNT without needle-like PANI, the as-prepared PANI/MWCNT nanocomposites sensors have higher sensitivity and repeatability, and better response/reproducibility towards ammonia at room temperature and also exhibits the higher sensitivity.

Micron-size multiphase nickel hydroxides with nanosheets structure were synthesized by coordination homogeneous precipitation method. Chemically oxidized NiOOH nanoparticles were added subsequently in order to improve their electrochemical performance. The samples were characterized by XRD and SEM. The results show that the NiOOH particles with flake-like morphology are dispersed randomly on the surface of the multiphase Ni(OH)₂. The simulated Ni/MH battery with the multiphase Ni(OH)₂ as positive active material has the discharge capacity of 306 mAh/g at 0.2C charge/discharge rate. The existence of chemically oxidized NiOOH in the nickel electrode exert great effect on the improvement of electrochemical performance. The discharge capacity of the sample added with 7 wt% NiOOH reaches 326 mAh/g at 0.2C and 311mAh/g at 2C.

Highly oriented single-crystalline TiO₂ nanowire bundle arrays on transparent conductive fluorine- doped tin oxide (FTO) substrates were prepared by hydrothermal method using the precursors of tetrabutyl titanate, deionized water and hydrochloric acid. The structure and morphology characteristics of all the samples were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). Results show that highly uniform and dense vertical arrays of single crystalline nanowire bundles with flat tetragonal crystallographic planes are formed. The nanowire bundles have a width of 110-210 nm (approximately 20-40 nanowires in each bundle), the single nanowire’s diameter is between 4-6 nm, and the length of the nanowire bundle is about 3μm. Dye-sensitized solar cells (DSSCs) made from oriented TiO₂ nanowire arrays anode are studied. The open circuit voltage, short circuit current density and fill factor of the cells are about 0.72 V, 2.9 mA/cm² and 0.42, respectively. The power conversion efficiency is about 0.88%.

Spectral properties of Nd³⁺ ion in Sr₃Gd₂(BO₃)₄ crystal were investigated, where the crystal was grown successfully by the Czochralski method. The absorption spectrum in the range of 200-1000 nm was measured. The fluorescence spectrum and lifetime were determined excited with 808nm wavelength, and the emission cross-section was calculated. Based on the Judd-Ofelt theory the spectral parameters were obtained, which were compared with others Nd-doped crystals.

ZnO nanorods were grown on different substrates (quartz glass, Si and ITO glass) by the wet chemical bath deposition (CBD) method at a relatively low temperature of 95℃. X-ray diffraction (XRD) and scanning electron microscope (SEM) results illustrate that the ZnO nanorod arrays with hexagonal wurtzite structure are grown densely and vertically on all the substrates, whereas the average diameter and length are found to be closely related to the substrates nature. High intensity near-band edge ultraviolet (UV) emission peak are observed in room temperature photoluminescence (PL) spectra for the ZnO nanorod arrays on all substrates, yet the usually observed defect related deep level emissions are nearly undetectable regardless of crystalline or amorphous, indicating high optical quality ZnO nanorod arrays can be achieved via this low temperature easy process chemical approach. Moreover, the small shift in the UV emission among different substrates is interpreted in terms of compress stress, which is further demonstrated by the Raman spectra measurement results.