Lead free piezoelectric ceramics with perovskite structure have attracted considerable attention as new piezoelectric materials because of their good piezoelectric properties. In this paper, The research progress and trend of (Na_0.5K_0.5)NbO₃-based ceramics were summarized and reviewed with emphasizes on the addition of new compositions and sintering aids, ions substitution and processing techniques. The future research works for the developments of (Na_0.5K_0.5)NbO₃-based lead free piezoelectric ceramics were also suggested.

Template-induced epitaxial crystallization of SiC, TiB₂ and SiO₂ in TiN/SiC, TiN/TiB₂ and TiN/SiO₂ nano-multilayer films and its influence on mechanical properties of the corresponding films were investigated. Results reveal that amorphous SiC, TiB₂ and SiO₂, which are more favorable under sputtering conditions, crystallize at smaller layer thicknesses due to the template effect of c-TiN layers. In particular, SiC crystallizes out in the face-centered cubic structure when its thickness is less than 0.6nm, which improves the crystal quality and structural integrity of the films; While TiB2, with thickness less than 2.9nm, forms hcp structure. The epitaxial orientation relationship between TiN and TiB2 is {111} TiN//{0001} _TiB2, <100> _TiN//<11-20> _TiB2; SiO₂, different from the above two, forms fcc pseudo-crystalline structure under a thickness of 0.9nm. With the crystallization of SiC, TiB₂ and SiO₂, hardness anomalous enhancement, i.e. superhardness effect, appears in those films. This phenomeon of hardness enhancement disappears rapidly when further increase the thickness of SiC, TiB₂ and SiO₂ layers, and at the same time, crystallines of SiC, TiB₂ and SiO₂ transform into their amorphous forms, respectively. The formation of these relatively soft amorphous layers, which blocks the coherent growth of the multilayer films, is the main reason of hardness decline at large SiC, TiB₂ and SiO₂ layer thicknesses.

A novel connectivity topological index( ^mB) based on the adjacency matrix and the ionic parameter of binding force(b_i) was derived in the present paper. The 0 and 1 order indexes⁰B and ¹B of ^mB were derived to correlate the long wavelength limit(λ) and the lattice energy (U) of 23 different types of transparent ionic crystals in infrared range. The relative coefficients (R=0.96904,
0.98523, 0.99185, 0.97635) of the derived equations are all in the range of higher level standards. Therefore, the results of present research could be useful for the design and evaluation of the long wavelength limit of ionic crystals.

The Yb ³⁺ -doped 32CaO-12Y₂O₃-24Al₂O₃-31SiO₂-1Yb₂O₃glasses were prepared by a melting method, then the glasses were annealed at 950C, 1050C and 1100C. The crystallographic structures of the glasses annealed at different temperatures were analyzed by XRD, the glass annealed at 1050℃ was observed by TEM. The spectroscopic properties of the glass before and after annealing were investigated. The results show that the glass annealed at 1050℃is YAG glass-ceramics with no impurity crystalline phase. The spectroscopic properties indicate that Yb3+ ions are preferentially entered into the YAG crystal phase. The transparent Yb:YAG glass-ceramics obtained are based on the controlled nucleation and crystallization of CaO-Y₂O₃-Al₂O₃-SiO₂ system glasses containing Yb ³⁺ ions.

The structure of hair was replicated via a sol-gel process using human hair as the template. When using silicate and TEOS as the precursor, the cell structure of hair cuticle was not well replicated. When using Ti (OnBu)4 as the precursor, however, titania microtubes were obtained, with nanopores in their wall and nanoporous platelets on their outer surfaces, which were derived from cuticle cells on hair surfaces. The nanopores in the microtubes acted as an effective nanoreactor for in situ synthesis of Au nanoparticles. The microchannels, nanopores and noble metal nanoparticles may provide a unique combination that would be attractive in such applications as catalysis, adsorption, and separation.

Nanocrystalline SiC powder was synthesized by carbothermal reduction of the precursor of carbon black and silica gel prepared by precipitationspray drying slurry of carbon black and water glass. The carbothermal reduction of the precursors can be completed at 1500℃ for 5h because the method provides intimate contact between the reactants. The product was characterized by XRD, BET, SEM and TEM, the influence of temperature and time on the reaction was also studied. The results show that the powder synthesized at 1500℃ for 5h has characteristics of high quality with an average crystalline size of 37nm and specific surface area of 12.4m²/g. It reveales that during carbonthermal reation, appropreately rising temperature and shortening reaction time will be favorable to obtain the reation product of SiC with high quality.

The present work was aimed at in-situ studies of temperature and time induced phase transition, morphologic evolution, growth mechanism, and microstructure of KTi₆O₁₃ nano-whiskers synthesized by calcination reaction using nanometer TiO₂ as the starting material. The experimental results indicate that the use of nanometer TiO greatly reduces calcination temperature with a suitable calcination temperature range of 900~1100℃. Observation of morphologic evolution and dynamic HTXRD analysis show that the phase transition and growth of KTi₆O₁₃ whiskers are quite sensitive to calcination temperature, and the morphologic evolution of KTi₆O₁₃ whiskers is mainly based on the fulminous phase transition at the initial stage and subsequent concatenation-parallel growth in length and diameter. The growth of KTi₆O₁₃ whiskers follows the concatenation-parallel growth mechansim developed in this study, which directly results in the formation of growth steps along the axis of the whiskers.

The preparation of ultrafine cubic Sb₂O₃ was studied by using oxychloride (Sb4O5Cl2) neutralized with ammonia under ultrasonic field. The results show that Sb₂O₃ obtained in the process is cubic crystalline and well-dispersed, which has an average particle size of 0.777μm when the ultrasonic power is 100W, the ultrasonic time is 30min, and the temperature is 20℃. The effects of ultrasonic power, time, ratios of distilled water to oxychloride, and temperature on the crystal structure and particle size of the Sb₂O₃ formed were investigated by means of XRD, SEM and laser sizer.

We used sucrose as carbon precursor and sodium silicate as silica precursor, and then generated a silica gel network and sucrose copolymer by the process of heat treatment. After carbonizing and etching the silica template, mesoporous carbons were obtained, whose pore sizes were 8-25nm. The obtained porous carbons were characterized by scanning electron microscope observation and nitrogen adsorption/desorption isotherms, we found that when the sucrose/ silica mol ratio was 0.33, pH ratio of the sol solution was 3, gelling tempreture was 80℃ and carbonization temperature was 850℃, the porous carbon prepared had BET surface area of 597.63m²/g, good pore volume, and mesoporosity, and had fine adsorption properties to rhamnolipid.

A series of La-Ni-O compounds were synthesized with modifying the mol ratio of La to Ni by citric acid complexometry and used as the catalyst precursors to prepare carbon nanotubes (CNT) by the chemical vapor deposition method (CVD). At the same time, H₂, N₂ and C₂H₂ were used as the reduction gas, protection gas and carbon source gas, respectively. The structures of the catalyst precursors before and after reducing by H₂ were characterized by XRD and the patterns of the CNT obtained from the catalyst precursors were characterized by TEM. The results show that only chemical compounds LaNiO₃ and La₂NiO₄ in the series La-Ni-O catalyst precursors have the ability to prepare CNT. However, the yield of CNT from the catalyst precursor LaNiO₃ is greatly higher than that from the catalyst precursor La₂NiO₄. And the reason is that the content of nano-meter metal Ni (111) crystal face in the productions from LaNiO₃ after being reduced is higher than that from La₂NiO₄. That is to say the higher the content of nano-meter metal Ni (111) crystal face and the larger the grain size, the higher the yield of CNT and the larger the inner diameter of CNT.

The structure and morphology of carbon nanotubes modified by high-temperature calcination and miling with high speed were studied. The surface area of carbon nanotubes was measured. The morphology of the carbon nanotubes electrocatalytic electrodes pressed at noal temperature was observed. Active red X-3B simulated wastewater was disposed by active carbon, graphite and carbon nanotubes electrocatalytic electrodes, respectively. The experimental results show that the stability of carbon nanotubes electrodes is good and the dye degradation of X-3B can reach
96.55%. The efficiency of carbon nanotubes electrodes is obviously better than that of active carbon and graphite electrodes.

The CdS nanobelts with high quality and even morphology were fabricated via a rapid evaporation route on Si substrate without any catalyst. XRD, TEM and SEM investigations reveal that the as-prepared samples are single-crystals of CdS nanobelts with a hexagonal wurtzite structure growing along the [001] direction. The VS model is proposed for the growth mechanism of CdS nanobelts.

MnO_x coatings deposited on a Ti/SnO₂+Sb₂O₃ were prepared by the thermal decomposition of Mn(NO₃)₂. Surface morphology and microstructure of the coating were investigated by X-ray diffraction and scanning electron microscopy. The electrocatalytic activity of the anodes was assessed by polarization curves and voltammetric charge at 25C and 1.0mol/L in aqueous H2SO4, and accelerated life tests were performed at 60C and 1.0mol/L in aqueous H2SO4 with an anodic current density of 4.0A/cm2. The aim of this work was to prepare anodes based on ternary oxides showing high stability and electro-catalytic activity in acid solution. The XRD analysis reveals that MnO₂ is formed at 200℃, after that, MnO₂ and Mn₂O₃ coexist between 300℃ and 400℃ and above 450℃ main composition is Mn₂O₃. It is suggested that calcination temperatures affect the electro-catalytic activity and the lifetime of the anodes. The anode possesses relatively low overpotential, when the coexistence of
MnO₂ and Mn₂O₃. The Ti/SnO₂+Sb₂O₃/MnO_x electrode, the MnO_x coatings prepared at 400℃, exhibits excellent electrocatalytic activity and higher coating stability with accelerated life of 39h.

Porous silicon (PS) due to its porous structure and large surface-to-volume ratio is prospective to substitute the traditional diffusion layer materials such as carbon paper or carbon cloth in miniaturized fuel cell based on MEMS technology. On singal-crystalline silicon n<100>(0.04--0.15Ω·cm) PS film was prepared. In order to make the preparation controllable, the effects of various experimental conditions including HF concentration, current density and anodization duration on porosity, pore depth and anodization rate were systematically examined. The C-V curves of PS film with 40% porosity, 500--700nm aperture and 60μm depth in 0.5mol/L H₂SO₄ solution indicate that PS electrode surfaces exhibit comparable catalytic activity with that of carbon paper. Therefore, the PS film shows potential application value in μPEMFCs .

With liquified petroleum gas as hydrocarbon, carbon felt as porous preform, C/C composites were fast fabricated by multi-coupling fields CVI process. C/C composites with density more than 1.7 g·cm^-3 were obtained with lower 650℃ in one cycle within 15h, and pyrocarbon microstructures were investigated with a polarized light microscope (PLM). At the same time, densification process and deposition mechanism of pyrocarbon were discussed. The results show that the density is uniform, and there is existing pyrocarbon with rough laminar(RL), smooth laminar(SL) and banded structure in the same sample.

A SiC coating was derived from a gaseous methyltrichlorosilane (MTS)/H₂ precursor by forced pressure-pulsed CVI (FP-CVI) process at low temperatures and reduced pressure. In the present experiment, the FP-CVI
process was studied, and the correlation between the coating thickness and the depositing conditions, i.e. the deposition temperature, the pressure, the deposition time per pulse and the pulse number was investigated. In 1000--1100℃and (5--25)kPa, the homogeneous β-SiC coating synthesized has (111) orientation. The coating thickness increases as the holding time per pulse and the pulse number increase. It shows a nonlinear behavior between the coating thickness and the pulse number. When the pulse number reaches 300 in all, the mass increment is 36.18% after coating on the carbon fiber.

In order to enhance densification efficiency and decrease the costs of preparation, a novel isothermal chemical vapor infiltration process for fabrication C/C composites was developed by decreasing the space of around preforms in the conventional hot wall reactor. With volume fraction of 28.7%, and infiltrated by the novel ICVI at ambient pressure and 1100℃, residence time of 0.1s, and methane as precursor, nitrogen as diluted gas, the 2D fiber felt preform was densified. The texture of the obtained sample was investigated by using a polarized light microscope and the flexural stength was determined by three-point bonding tests, after the tests, the morphology of the fracture surface was observed by using SEM. The resuts show that the bulk density of the C/C composite prepared in 125h is 1.73g/cm³, and the density distribution is uniform. Its texture is pure rough laminar. Its flexural strength is 250.87MPa. Its flexural modulux is 29.29GPa. The C/C composite exhibits a pseudo-plastic failure behavior.

2D C/SiC and niobium alloy NbHf10-1M were successfully joined. The joining material, posited between 2D C/SiC and NbHf10-1M, was a lamination formed by a main interlayer of Ti-Cu and an assistant interlayer of Cu. The joining process consisted of solid diffusion bonding and transient liquid phase diffusion bonding (TLP-DB). The study shows that the increase of the thickness of assistant interlayer Cu can decrease the thermal stress in joint. The Ti-Cu liquid alloy formed in TLP-DB process, has good wettability with C/SiC and easily infiltrates into C/SiC and wrapes the C fibers on the joining surface.
The highest shear stress of joint is 14.1 MPa.

An in situ reaction-bonding technique was developed to fabricate porous silicon carbide (SiC) ceramics in air from SiC and Al₂O₃, using graphite as the pore former. The main phase is SiC and the bonded phases are mullite and cristobalite in porous SiC ceramics. The reaction-bonded SiC ceramics possess connected open pores. The linear shrinkage of the specimens before and after sintering is between --1.5% and +1.5%. Open porosity decreases with the sintering temperature and forming pressure, but increases with the graphite content. Bulk density and mechanical
strength increase with sintering temperature and forming pressure, but decrease with the graphite content. The pore size distribution takes on a bimodal distribution when the graphite particle size is 20.0μm. In addition, as-fabricated porous SiC ceramics exhibit low coefficient of thermal expansion, high N₂ permeability, excellent high temperature-oxidation
resistance, good acid endurance and relatively bad alkaline endurance.

SiC particles, pure aluminum powder and silicon powder were applied to prepare SiC particles reinforced Al-matrix composites for electronic packaging application. Al-matrix composites reinforced with SiC particles were fabricated by SPS. The composites were dense and SiC particles distributed homogenously in Al-matrix. According to the investigation of SPS process, the sintering process of the composite, belongs to a reactive sintering, the majority of sintering shrinkage can be finished in a short period. Effects of SiC volume fraction and particles sizes
on thermal conductivity and coefficient of thermal expansion were investigated. The results indicate that thermal conductivity and coefficient of thermal expansion decrease with the increase of SiC volume fraction, and thermal
conductivity increases but coefficient of thermal expansion decreases with the increase of SiC particles sizes.

The neodymium doped yttrium aluminum garnet (Nd:YAG) powders were synthesized by the low temperature combustion and the transparent ceramic disks with 9mm in diameter and 1mm in thickness were prepared by the vacuum sintering at 1700℃ for 5h after being 300MPa model pressing. The transparent ceramics were characterized by optical transmittance, field emission gun-environment scanning microscope and the study were carried out on the qualitative relationship between the optical transmittance and
microstructure parameters using stereology theory and method. The results show that the optical transmittance of Nd:YAG transparent ceramics with 9mm in diameter and 1mm in thickness is about 45% in visible region and 55% in infrared region and increase with the incidence light wavelength increasing. The optical transmittance increases with three dimensionally corresponding diameter (D_3S ) of grain climbing and reaches the theoretical value of single crystals when D_3S is 20μm. The optical transmittance decreases with the grain and single grain mean specific area enhancing and mean free distance of grains adding.

A series of
Ce-Zr-Mn compound oxides oxygen storage materials were synthesized by a
co-precipitation method and characterized by X-ray diffraction (XRD), BET,
oxygen adsorption and temperature programmed reduction (TPR). The modification of the textural and structural properties, oxygen storage capacity, redox
behavior, and phase changes were investigated. The results show that incorporating a small amount of manganese into Ce-Zr solid solution can remarkably improve the oxygen storage capacity and decrease the temperature of the reduction of the oxygen storage materials. Moreover, only a stable
cubic phase CeO₂-ZrO₂ solid solution is formed. The Ce-Zr-Mn Compound oxide indicates the highest oxygen storage capacity (OSC) and excellent property of resistance to aging when manganese content (mole fraction) is
0.025, its surface area can reach 57.8m²/g after aging 5h at 1273K.

The samples of Bi ₂ V _0.9 Cu _0.1-x Sn _x O _5.5-δ (0≤ x ≤0.75) were prepared by solid-state reaction. Room temperature powder X-ray diffraction (XRD) indicates that the synthesized compounds present the tetragonal γ-phase structure. The measurement results show that doped-Sn benefits to the control of microstructure of the sample and favor its mechanic property though it doesn’t further improve the electrical conductivity of the system. The oxygen permeation measurement result indicates oxygen transport in Bi ₂ V _0.9 Cu _0.1-x Sn _x O _5.5-δ system is controlled mainly by the process of surface oxygen exchange.

β-Ca ₃(PO ₄) ₂/CaSiO ₃ (β-TCP/CS) composite bioceramics with weight ratio of 50:50 were fabricated by using the β-TCP/CS nano-composite powders. The β-TCP/CS composite bioceramics with >96% relative density and 120nm grain size were obtained after sintering at 1150℃ for 5h. The bending strength of the samples reached about 126MPa, which was similar to those of the human cortical bone. After soaking in simulated body fluid for 1 day, the samples were completely covered wity hydroxyapatite layers. The degradability of the
samples reached 10.1% within 28 days in~ vitro. The results suggest excellent
in~ vitro bioactivity and degradability of the β-TCP/CS composite
bioceramics. Therefore, these β-TCP/CS composite bioceramics may be
potential candidates as good mechanical strength, bioactive and degradable
biomaterials for hard tissue repair applications.

A new type of bioactive calcium
phosphate cement with an excellent property of anti-washout for bone replacement was prepared by using cellulose as additive and non-aqueous solvent as liquid. The property of anti-washout, physical chemistry performances, hydration products and the biocompatibility were investigated. The results indicate that the improved CPC has an excellent anti-washout property and can be easily shaped as well as injected. The addition of the cellulose does not have obviously effect on the setting time and compressive strength of the CPC hardened body. The cultural cells are attached, dispersed and preferentially proliferated on the surface of the improved CPC. The fabricated biomaterials can be used as the filler of the bone defect or vertebroplasty or kyphoplasty in micro invasive surgery.

A polymeric precursor method by using citric acid as the chelating agent was invesigated and single-phase and well-crystallized BaSm₂Ti₄O₁₂ powder was synthesized at 1000℃ for 3h. As a comparison, an oxalate co-precipitation method was applied to synthesize BaSm₂Ti₄O₁₂ powder, but 1300℃ was needed to get the pure BaSm₂Ti₄O₁₂. The different phase behavior and reaction sequences are here believed to answer for the different calcining temperatures needed via these two wet chemical methods. In the co-precipitation method, when heating the precipitate, intermediate phase Sm₂Ti₂O₇ reacts with BaTi₄O₉ and BaTiO₃ to produce BaSm₂Ti₄O₁₂, which is
similar to the solid-state route. As to the polymeric precursor route, however, BaTi₂O₅ intermediate phase produces during the thermal decomposition process, which results in totally different reaction sequences from the solid-state reaction mechanism, and promotes the formation of BaSm₂Ti₄O₁₂ phase.

Based on the electromagnetic wave propagation laws, a three-layered sheet radar (microwave) absorbing system with the impedance-graded structure was designed. The surface layer, composed of TiO₂, easily realizes matching to the free space and protection from destroying. The last layer, made up of magnetic micropowder (MMP) ballmilled from Fe, Co, etc, has significant absorbing effects. The medium layer, comprised of MMP and carbon fibers, forms the impedance-graded structure from the surface to the last layer. The results of experimental measurement show that reflectivity for the three-layer absorber is below --8dB in the frequency range of (8--18)GHz. Tensile strength is 10.8MPa, and peeling strength is 75.2N/cm, satisfying the use of engineering.

Crystalline β-BBO thin films were successfully prepared on (001)-oriented Sr ²⁺ -doped α-BBO substrates by using liquid phase epitaxy, pulsed laser deposition and vapor transport equilibration techniques. The films were characterized by X-ray diffraction and X-ray rocking curve. The present results manifest that the β-BBO thin films grown on Sr ²⁺ -doped α-BBO substrates have larger degree of orientation f value and smaller X-ray rocking curve FWHM than the ones grown on other reported substrates. Compared with other substrates, α-BBO has the similar structure, the same UV cutoff and the same chemical properties to β-BBO. These results reveal that Sr ²⁺ -doped α-BBO single crystal may be a promising substrate proper to the growth of β-BBO films.

Using a sol-gel route with polyvinyl pyrrolidone as the surfactant, the carbonyl iron microparticles were uniformly and fleetly coated by SiO₂ nanoshell, whose thickness was conveniently different by changing reaction time. The influences of shell thickness on the properties of the Fe/SiO₂ core-shell particles were studied. The results show that increasing the thickness of SiO₂
nanoshell (D_shell), the anti-oxidation property of the Fe/SiO₂ core-shell
composite particles is obviously improved while microwave permittivity decreased monotoneously. The saturation magnetization shows a maximum
value while both the coercivity and remnant magnetization show minimum
values at D _shell=15nm. Meanwhile, the radar absorbing coating based on the
Fe/SiO₂ core-shell composite particles with D _shell=15nm shows a maximum
bandwidth of more than 10GHz, in which the reflective loss is less than --8dB.

The damaging effects of nanosized
TiO₂ on human Bel-7402 liver cancer cell were investigated by means of HE
dye method and MTT colorimetric assay under condition of photoinduce. The
influences of nanosized TiO₂ content, and irradiation time on cancer inhibition were systematically studied, and the inhibition mechanism was primarily discussed. The results show that nanosized TiO₂ exhibits good inhibition effects under appropriate TiO₂ concentration, and the inhibition process obeys first order reaction rule approximately; In addition, activity oxygen produced by nanosized TiO₂ under illumination can react with organicmolecules in and out the cancer cell membrane, so that lead to damage cell structure, result into imbalance of Ca ²⁺ in the cancer cell, and induce microtubule reassembly due to expression changes of microtubule-associated protein-2, which are responsible for the apoptotic and dead cancer cells.

Single-crystalline WO₃ nanorods were fabricated by a hydrothermal method in the presence of Na₃PO₄. The properties of products were characterized by SEM, TEM, XRD and EDX. The effects of other alkali salts (NaCl, NaNO₃ and Na₂SO₄) on the morphologies of WO₃ nanocrystals were also investigated. The resuts show that Na₃PO₄ plays an important role in synthesizing the WO₃ nanorods. As the content of the assisted Na₃PO₄ reaches 50g, the WO₃ nanorods synthesized in this reaction system have better quality.

Nanocrystalline NiZn ferrite powders with spinel structure were prepared by a new chemical method---refluxing method. Refluxing time and the mechanism of NiZn ferrite spinel formation were discussed based on the XRD analysis and pH value measurement. The results show that the optimum refluxing time is 6h. The particle sizes of Ni_0.5Zn_0.5Fe₂O₄ nano-powders prepared by the refluxing method are about 10~20nm with TEM analysis, and the results of HRTEM AND SAED approve that Ni_0.5Zn_0.5Fe₂O₄ nano-powders prepared are with the single spinel phase. VSM results reveal that the prepared Ni_0.5Zn_0.5Fe₂O₄ powder has typical soft magnetic characteristics.

We succeeded in the fabrication of polyananiline/Bi₂Te₃ heterostructured nanorods by means of two-step electrochemical depositions from aqueous solution. In the first step, polyaniline nanotubules were electrodeposited in alumina template. In the second step, using conducting polyaniline nanotubules as template, Bi₂Te₃ nanorods were electrodeposited. Characterizations of XRD indicate that the deposited Bi₂Te₃ rods are highly textured in the {110} direction. Furthermore, FESEM and TEM analysis show that the Bi₂Te₃ nanorods are well enveloped in polyaniline tubules in pores of alumina template. The two-step electrodeposition method provides a promising path for fabricating organic-inorganic heterostructured nanorods.

Dense BaTiO₃ ceramic fibers were obtained by solvothermal treatment of the green gel fibers, which were drawn from a sol using barium acetate hydrate and catechol-complexed titanium isoproposide as starting materials, at 180℃ for 12h in n-hexane following a heat process to 1100℃ with a heating rate of 1℃/min for crystallization. The as-synthesized BaTiO₃ ceramic fibers were characterized by X-ray diffraction (XRD), Infrared (IR) spectra and scanning electron microscope (SEM) techinques.

In this paper, uniform and dispersive CaSO_4·0.662H₂O nanorods were synthesized in reverse micellae (W/O microemulsion) containing AEO, cyclohexane, and n-pentanol. The average diameter and length were 50nm and 800~-1600nm respectively. The study of the preparation conditions showed that the preferred synthesis conditions were: ω(H₂O/surfactant)=6~15, γ(oil/surfactant)=5~12 and the reactant concentration 0.05~0.3mol/L. The property study showed that nano calcium sulphate could produce stronger purple light emission at 339nm. This property would have a very expansive application prospect in the fields of nano-electric devices and so on.

The YBCO precurcor oxide-water sol adulterated with Au clusters was successively prepared by pulsed laser ablation at the interface of Au target submerged in flowing YBCO precurcor oxide-water sol, YBCO precurcor oxide-water sol with Au clusters dopant was first obtained, then YBCO hybrid materials were obtained after calcination in air. The sol was characterized by TEM and the hybrid materials were characterized by XRD and SEM with an EDX analysis. The TEM and XRD results show that the size of YBCO hybrid materials doped with Au clusters is smaller and its crystallization degree is obviously reduced. EDX analysis indicates that there’s no evidence showing the deviation of Y, Ba and Cu in the YBCO hybrid materials, but Au clusters are detected only in a few regions, which indicates that Au clusters may agglomerate during high temperature calcination.

Microwave sintering is a new and highly active kind of singtering technology which is superior to the technology of traditional sintering. With highly pure AlN powders and without singtering additives, AlN transparent ceramics were obtained by using microwave sintering at 1700℃ for 2h. The result of experiments indicates that the AlN transparent ceramics prepared by this process have fine grain sizes (less than 10μm), uniform grain distribution, and no oxidized phrases. From above analysis, it is proved that AlN transparent ceramics can be sintered at low temperature by the microwave sintering technology.

Magnesium-doped zinc silicate (Zn₂SiO₄:Mn) was prepared on oxidized silicon wafer by a simple sol-gel process. The crystallinity of films was characterized by X-ray diffraction and optical properties were measured by UV-Vis and photoluminescence spectra. The influence of annealing temperature on films properties was also studied systematically. It’S found that proper ZnO can enhance the photoluminescence intensity of Zn₂SiO₄:Mn films. And the mechanism was explained by using the model of quantum confinement-luminescence center proposed by G.G. Qin.

Li-N-H codoped p-type ZnO films were fabricated on glass substrates by DC reactive magnetron sputtering. X-ray diffraction, Hall-effect measurement, photoluminescence spectra and transmittance spectra were used to characterize the films. The results show that the codoped films are highly c-oriented with a p-type conduction, resistivity of 25.2Ω·cm, Hall mobility of 0.5cm²/(V·s), carrier density of 4.92×10¹⁷cm^-3, and transmittance of about 90%.