Ultradispersed nanodiamond powder synthesized by explosive detonation was used for the pretreatment of mirror Si substrate for nucleation and growth of diamond by microwave plasma-CVD. Compared with the scratching pretreatment,
it is found that the pretreatment method by coating substrate with the slurry loading nanodiamond powder not only enhances both of density (up to 10⁹ cm^-2
and nucleation rate, improving the quality of grown-up film greatly, but also controls nucleation easily. In addition, this pretreatment is also very
cost-effective, non-damaging, and reproducible as well.

The application of H₂S gas sensing materials and research progress on H₂S gas sensing materials in the form of solid electrolytes and semiconductive oxides (sintered block, thick film andthin film) were reviewed in this paper, and the latest development of room temperature H₂S gassensing thin films was discussed especially.

A high temperature in-situ observation method was used to observe two different states of convection: diffusive-advective flow
and diffusive-convective flow. Characteristic diffusion distance L can be easily measured from Schlieren photograph and it ranges from
0.01～0.1cm for two different states of convection. By observation of rotating crystal growth processes in the KNbO₃ melt, the widths of
interfacial concentration, heat and momentum transition zone were obtained, which are 7.5×10^-3cm, 8.6×10^-2cm and 4.4×10^-1cm respectively.

An investigation of growth kinetics of KNbO₃ crystal related to the different states of the convection in high temperature melts was performed
by this method. Irrespective of the state of convection in the melt, at the lower supercooling two dimensional nucleation growth was obtained.
At the same supercooling, the discrepancy between the growth rates for two different states of convection was assigned to the buoyancy convective
enhancement of the interfacial mass flow. The free energy per unit length of a step ε, and the thermodynamic potential barrier for two-dimensional
nucleation Δ G*, were calculated from the experimental data for two different states of convection. These data are significant for consideration of the
influence of convective flow on the interface growth kinetics. The effect of convection is to enhance the sharpness of the interface.

The specific heat of LiIO₃ crystal grown in space and on the earth from --110-350℃ wasmeasured by the DSC method. The fitting equations from experimental data of specific heat weregiven. The maximal deviation of the values calculated by empirical equation from experiment datawas about ±1/%. The results show that the specific heats of LiIO₃ crystas grown in space and onthe earth have no obvious differentiation.

The growth, structure, spectra, laser preperties and some physical properties of a new laser crystal Nd:Sr₅(PO₄)₃F (Nd:SFAP) were
studied in order to search and evaluate the applications of the crystal to laser. The Nd:SFAP single crystals were successfully grown by Czochralski method and the laser experiment of the crystal crystal pumped by laser diode
(LD) was demonstrated. The properties of as-grown crystal were measured by advanced equipments. Experimental results showed that Effective distribution
coeffcient K_eff of Nd was 0.52. π polarization light with wavelength of 806nm was the best pumping light. The fluorescence lifetime of 2 at % Nd:SFAP
crystal was 175μs. The pumping threshold of Nd:SFAP laser was 15mW and its slope efficiency was 31.8%. From the investigation we can draw a conchusion:
the Nd:SFAP crystal is an ideal laser mateiral for lower power lasers, but it isn’t suited to be applied to higher power lasers.

Single crystals of KLnN(Ln=La, Ce, Pr, Nd, Sm) can be grown in water solution with pH≈1～2 at about 40℃. Crystals of KLnN
(Ln=La, Ce, Pr, Nd) are orthorhombic with space group Fdd2. KPrN crystal was grwon and its crystal structure was determined for the first time.
The KPrN crystal parameters obtained by the direct method are as follows: a=21.411(3)A, b=11.2210(10)A, c=12.208(2)A, Z=6, R=0.0240. The TG-DTA curves of KLnN(Ln=
La, Ce, Pr, Nd, Sm) demonstrate that the processes of dehydration , melt, irreversible phase transition and decomposition of NO^-₃ take place in sequence with the temperature increasing(except KCN). There are three steps in the
decomposition of NO^-₃ in KLnN(Ln=La, Nd, Sm) while two steps in KLnN(Ln=Ce, Pr). K₂Ln(NO₃)₅·2H₂O are formed at about 225℃
by the reaction of the starting materials of KNO₃ and Ln(NO₃)₃·nH₂O.

Stable and metastable phase equilibria in a binary Bi₂O₃-SiO₂ system were studied and a complete phase diagram
of the system was proposed with DTA and XRD. A peritectic reaction L + SiO₂←→Bi₄Si₃O₁₂ at the SiO₂-rich side of stable phase diagram was identified to have peritectic temperature
at about 1030℃ and peritectic point close to the end of the peritectic isotherm. Bi₄Si₃O₁₂ was observed to be a nearly congruently melting compound and liquidus of the peritectic
reaction was identified by quenching microstructure method. Crystallization behavior of Bi₂O₃
-SiO₂ system was also investigated. The
results show that metastable Bi₂SiO₅ crystallizes out at 845℃.

By using ammonium aluminium sulfate and ammonium hydro-carbonate as the starting materials, the synthesis of ammonium aluminium carbonate hydroxide (NH₄AlO(OH)HCO₃)
was studied. It was found that NH₄AlO(OH)HCO₃ can be synthesized by adding ammonium aluminium sulfate solution to ammonium hydro-carbonate solution
with a adding rate less than 1.2L·h^-1. Under other conditions the precipitate was γ-AlOOH in the experimental range. The sequence of phase transformation of
γ-AlOOH during heating was found to be γ-AlOOH →γ-Al₂O₃→δ-Al₂O₃→θ-Al₂O₃→α-Al₂O₃; while that of NH₄AlO(OH)HCO₃ was found to be NH₄AlO(OH)HCO₃ →amorhous Al₂O₃→θ
-Al₂O₃→α-Al₂O₃. The transformation temperatures of NH₄AlO(OH)HCO₃ to θ-Al₂O₃ and α-Al₂O₃ were both about 100→ lower than those of γ-AlOOH. γ-AlOOH can transform to
α-Al₂O₃ completely by calcining at 1200℃ for 1h, and the obtained powder,with a particle size of 150nm, can be sintered to 84.46% relative density at 1450→
for 2h. NH₄AlO(OH)HCO₃ can transform to α-Al₂O₃ completely by calcining at 1100℃ for 1h, and the obtained powder, with a particle
size of 70nm, can be sintered to 97.80% relative density under the same sintering condition.

Pure Ba₂Ti₉O₂₀ powder was prepared by using traditional ceramic technological process with BaTiO₃ and TiO as the starting raw materials. In order to explore
the phase development sequence, the mixed powder of BaTiO₃ and TiO₂ was calcined with different temperatures from 800℃ to 1150℃ and different keeping
hours from 1/60 to 64h, then identified by X-ray powder diffraction. The results show that the pure phase of Ba₂Ti₉O₂₀ can be obtained at 1000～1150℃/4～32h,
and the homogeneity of the constituents is an important processing factor for obtaining pure Ba₂Ti₉O₂₀ powder.

Uniform acicular hematite particles were prepared by two steps hydrothermal method from Fe(OH)₃ gel. The effect of nucleating temperature,
pH and Sn⁴⁺ ions on the morphologies of hematite particles was studied. The experiments showed that uniform acicular particles can be obtained. First
the suspension of Fe(OH)₃ aged at 50～80℃ for 2h, crystal growing agent was then added, and put into a stainless steel autoclave with
stirring at 150～170℃ for 1.5h. The key problem of the poor repeatability of experimental result was solved. The results were characterized
by TEM and XRD.

The influences of different kinds and contents of dispersents and pH values of slumes on thestabilities of the slumes were studied. The slurry with suitable viscosity, mobility, stability wasobtained, which can be used to prepare α--A1₂O₃ microporous membrane.

The mechanism of the B-site ordering and disordering in Lead Magnesium Niobate (PMN) was examined by using both heat treatment and La-doped methods. The B-site structural ordering characteristics were exposed by
X-ray diffraction (XRD), selected area electron diffraction (SAED) and high-resolution electron microscopy (HREM). The reason of the pyrochlore
phase presenting with the La-doped increased was studied. Based on the analysis of dielectric properties, the increase in the degree of diffuse
phase transition (DPT) in annealed and La-doped PMN observed was interpreted as the Mg²⁺:Nb⁵⁺=1:1 nonstoichiometric short-range
ordered domain accompanied with the segregation of the Nb⁵⁺ in the disordered area. Furthermore, it was demonstrated that the kinetic mechanism
of the ordering micro-domain growing was ion diffusion equilibrium by the effects of the heat treatment on DPT properties of the various amounts
of La-doped.

Sintering behavior, microstructure and microwave dielectric properties of the nonstoichiometric Ba(Mg_1/3Ta_2/3(1+x)O₃ with --0.01≤ x≤0.01 were
investigated. The sintered density was improved by increasing Ta concentration. The ordering parameter S was not only related to the presence of defect in the specimen
but also sensitive to the type of defects. The presence of B-site vacancy might hinder the ordering procedure much more significantly than that of A-site vacancy. The
Q· f value decreased and the dielectric constant increased with the increase of tantalum contents.

The possibility of Sr₂V₂O₇ to be a resistive oxygen-sensitive material was evaluated by studying its electrical properties, bulk and surface resistances of
ceramic Sr₂V₂O₇ at different temperatures and/or oxygen partial pressures were measured experimentally. After mathematical process of the data, some properties of
Sr₂V₂O₇ were achieved. Phase transformation has little influence on the electrical properties; the activation energies for surface and bulk conductances
are 1.91eV and 1.31eV respectively; It has an oxygen sensitive factor m=6 and a relative high temperature coefficient. Sr₂V₂O₇ needs surface
modification if it serves as a potential exhaust gas sensor material.

The dynamic fatigue behaviours of Si₃N₄ material at room temperature, 800and 1100℃ were investigated. It was discovered that the fracture strength
decreases with the increase of σ at a high stress rate, and that the stress corrosion exponent n decreases also with the temperature increasing. The former is the same
as that in transformation toughening ceramics and glass-ceramics, but is of some deviation from the theoretical prediction. The fractographic observation showed that
the dynamic fatigue failure mechanism of Si₃N₄ at elevated temperature is the softing of the glass phase in grain boundaries.

Brittle thin plate with a straight-through crack under biaxial and uniaxial tension in-plane was investigated by thermomechanical method. The
critical stress intensity factor under those two loading modes was measured with disk-shaped specimens of glass and ceramics. The results show that the
crack resistance of brittle materials increases with increasing stress parallel to the crack plane. The effects of biaxial stress reveal that the conventional
criterion with the stress intensity factor is imperfect for biaxial stress issues. It is demonstrated that the crack opening and growth is governed by
the strain at the crack tip.

The formation behavior of the composition of β₁₀-Sialon(Si_5.23Al_0.77O_0.77N_7.23) plus 7.26wt% Nd-melilite solid solution (Nd₂Si₂AlO₄N₃) prepared by
pressureless sintering was studied. Nd ions in the composition enter α-sialon at low temperature, dissolve in the liquid phase of the material with
temperature increasing. Melilite solid solution can be formed as a grain boundary phase of the ceramics by heat-teatment at 1550℃ for 24h. The oxidation behavior
of the hot-pressed and post-sintered samples was also investigated in the range of 1000～400℃. The melilite solid solution doesn’t caues severe cracking
of the material in oxidation at 1000℃ At high temperature, the oxidized surface of the sample contains preferentially oriented A-Nd₂Si₂O₇ grains and bubbles,
which are formed because of the decrease of the silicate viscosity, incurred by the accumulation of Nd ions to the surface.

(1-n)SiO₂-nAl₂O₃ (n=0, 0.01, 0.1) aerogels were prepared by using a sol-gel route and followed by the supercritical drying technique. Nano-ZrO₂ precipitates
were introduced into the pores of the aerogels. Photoluminescence of the ZrO₂/(1-n)SiO₂-nAl₂O₃ nanocomposites was measured. The results show that the luminescence
peak at about 540nm (2.30eV) for nano-ZrO₂ bulk sample shifts to 400nm (3.10eV) (blue shift) for ZrO₂/(1-n)SiO₂-nAl₂O₃ nanocomposites, when the excitation
wavelength is 316nm (3.92eV) at room temperature. The blue shift is about 140nm. The relative intensities of the luminescence peak change with the doping amount of the
nano-Al₂O₃. Mechanism of change of the luminescence peak in the visible region was proposed.

Nano-TiO₂ and micro-TiO₂ thick films were prepared on a-Al₂O₃ substrates by silk netlithograph method, the measured film resistance of nano-TiO₂ was higher than that of micro-TiO₂ in experimental temperature range, nano-TiO₂ film demonstrated more change as the O₂ partialpressure changed. XRD and SEM were also used to characterize the stucture of the prepared films.

Friction and wear characteristics of Ce-TZP-(Al₂O₃ ) against Cr₁₂ steel under the loads of 100--500N were studied in different environments (
air, water, acetic acid, ammonia solution). The wear mechanisms of zirconia ceramics were analyzed based on the morphology and phase composition of all
worn surfaces. Under the load of 100N, the high friction coefficient and wear rate were measured and the main wear mechanism was abrasive wear in air; whereas
in liquid, the friction coefficient and wear rate were all low, and delamination became dominant. Under the load of above 200N, Martensitic transformation occurred on the worn surfaces, and brittle fracture processing
was the controlling mechanism. The friction coefficient decreased while the wear rate increased with increasing load.

The biological friction and wear properties of UHMWPE rubbing against SiC ceramics lubricated with fresh plasma were evaluated by using Falex at 37℃, and the surfaces of the specimenwere observed with SEM and surface profile meter. The results show that the friction coefficient of UHMWPE against SiC is about 0.05, and the wear factor of UHMWPE is lower than8.45×10^--10mm³/N.m. The wear loss of SiC ceramics is very small. Based on the results of XPSanalysis, the mechanism was proposed.

Zro₂(3Y) precursor which uniformly mixed with Y2O3 was prepared via hydrous-zirconia,which was prepared by microwave heating, coated with Y(OH)₃ by heterogeneous nucleation processing. After ZrO₂(3Y) precursor was calcined, its phase structure was analyzed by XRD. It wasfound that m-ZrO₂ didn t exist in ZrO₂(3Y) powder at room temperature. The results indicatedthat Y₂O₃ can uniformly be added in ZrO₂ by coating means and the amount of metastable t-ZrO₂ in ZrO₂(3Y) powder can be increased.

Boehmite (γ-AlOOH) powder was first prepared by Sol-Freeze Drying method using cheap AlCl₃·6H₂O as raw materials, and then γ-Al₂O₃
nanopowder with the average diameter of 6nm and α-Al₂O₃ nanopowder with the mean diameter of 30nm were obtained by the calcination of the above
γ-AlOOH powder at 500 and 1100℃, respectively. The potential～pH diagrams of Al-H₂O system at 25 and 90℃ were presented, separately. Thermodynamic analysis of the main reactions in the process of thermal
decomposition of Al(OH)₃ was also made using Temkin-Schwarzman’s method and by means of regression analysis. Investigations of the potential-pH diagrams of
Al-H₂O system and thermodynamic analysis of the thermal decomposition of Al(OH)₃ provide a certain guide for the formation of boehmite sol and the
heat treatment of boehmite powder, respectively.

Through the testing of K_IC value of 14mol%Ce-TZP and Ce-TZP/Al₂O₃ layered microcomposites with different fabric parameters, the influence of
Al₂O₃ layer thickness and Ce-TZP content in Al₂O₃ layer on the mechanical property of the materials was analysed in material and mechanics
perspective. In order to obtain the qulitatively explanation of the influence of Al₂O₃ layer on the transformation zone shape and transformation quantity, the Laser-Ramman
Micro Zone analysis on the section and side of K_IC sample fractured was adopted, thus the toughening mechanism of materials such as Ce-TZP/Al₂O₃ layered
microcomposites can be expected.

Nano-scale Y₂O₃:Eu³⁺ powders with different grain sizes and Eu³⁺ concentrations were prepared by chemical process, and dealed with coating. It was found that the Eu³⁺ critical concentration of nano-scale Y₂O₃:Eu³⁺ powders was increased obviously, and it caused the luminescentintensity improved. In addition, because the hanging bonds on the surface of coating nano-scaleY₂O₃:Eu³⁺ powders were mostly vanished, the luminescent intensity was further enhanced.

Al₂O₃ ceramics were successfully superfast densified by spark plasma sintering (SPS) under the conditions of heating rate as high
as 600℃/min, no holding time at the sintering temperature from 1350 to 1700 ℃ and then fast cooling to 600℃ within 3 minutes. It showed that Al₂O₃ ceramics could reach to a
higher density at a lower sintering temperature by SPS, as compared with by normal pressureless sintering. The bending strength of pure Al₂O₃
ceramics superfast densified by SPS at the temperature range of 1400～1550℃ was as high as about 800 MPa, which is an excellent datum being of more
than a double of the bending strength for normal pure Al₂O₃ ceramics. SEM micrographs showed that the intragranular fracture was a preponderant
fracture mode in these Al₂O₃ ceramics being of very high bending strength.

Supported;and unsupported mullite membranes were prepared by sol-gel process from bothtetraethyoxysilane (TEOS) and aluminium nitrate precursors. Structure, appearance and poresize of the mullilte membrane were characterized by DAT-TG, XRD, SEM and BET. The resultsshowed non-crystal xerogel membrane transformed into the mullite membrane after heat treatmentat 1050℃. The most concentrative pore diameter of unsupported mullite membrane was about3. 71nm.

The influence of proceeding treatment technology on properties of Ni--HAP composite coatingwas investigated. From the results, the degree of combination of the matrix being treated byelectropolishing with the composite coating was denser and firmer than that of the matrix beingtreated by mechemical polishing with the composite coating. As a result, a new-applied noncorrosive steel-based Ni-HAP composite biomaterial was produced. Moreover, a tentative studyabout the technology and mechanism of getting high-HAP contents coating was done.

The phase composition and microstructure of boron carbide coatings by plasma spray wereinvestigated through X-Rad, XPS and SEM. The porosity and microhardness of the coatings werealso measured. The results showed that The plasma spray boron carbide coatings by using theimproved F4-MB plasma gun under atmospheric pressure had the lower porosity 3%~4% and theclosed microhardness H_v>28GPa compared with the coatings obtained under up to 2kpa argonpressure.

The characteristics of phase transformation and microstructure of nano titanium oxide powders during plasma spraying were discussed. XRD and TEM methods were used to determine thecrystal structure and microstructure of the plasma sprayed nano titanium oxide powders. Moreover, the nano titanium oxide powders were also sintered in a furnace and characterized with XRDand TEM. The results show that plasma spraied titanium oxide powders belong to the triclinicsystem, whose particle size ranges from several nanometers to one hundred nanometers

WO₃ thin films were fabricated on ITO glass substrates by the spin-coating technique using H₂WO₄ and H₂O₂ as precursors. The films annealed at 150℃ for 1h show dynamic coloration and bleaching efficiencies of 10.0,
8.6 cm²/C respectively at 633nm during cycling between --1 and +1V (vs. SCE) in LiClO₄/PC at the scan rate of 20mV/s. The films annealed at 350℃ show improved cycling stability while losing some efficiency.
The films annealed at 150℃　have also been electrochemically cycled by a constant current charge injection, which is found to be more easy to control
the amount of charge injected into the films, and avoid overcharging the films, especially the surface layer.

The effects of reaction-sintering temperature and time, forming pressure, carbon black contentand Fe powder content on in-situ SiC powder content in reaction-sintered ZrO₂-SiC(p) ceramicswere studied by using artificial neural networks. The optimum process parameters were optimizedwith genetic algorithm.

According to the method proposed by Swarts and Shrout, PMN ceramic material with single perovskite phase was prepared, and no any
pyrochloride one was detected by X-ray diffraction analyses. SEM observation shows that the sample was dense without the apparent
pores. The hysteresis (P～E) loop was measured by using a Radiant Technology RT 66a and an amplifier. The change of P～E loop of the
sample with the frequency measured shows that the dependence of the polarization on the field of PMN relaxor ferroelectric ceramic material
at low frequency (e.g.10 Hz) is a curve without any hysteresis at room temperature, and P～E loop appears with the increase of frequency
measured(e.g.>100 Hz), the higher the frequency, the larger the P～E loop, which differs from that of normal ferroelectrics.

SrTiO₃ GBBL capacitor material containing Nb₂O₅, Y₂O₃ , Li₂O, single sintered at 1120℃,was reported. The result shows the material has better dielectric dispersion and lower dielectricloss than usual SrTiO₃ GBBL materials contaiming Li₂O.