Submicro-composites of core-shell C/Co were synthesized by a two step process of liquid synthesis and heat treatment with C as core- and Co as shell-material, and then their microwave absorption properties were investigated. Results show that the heat treatment process can enhance the crystallinity of the prepared C/Co-composites and alter their morphology, i.e. transforming from a core/shell structure with snowflak like shell to a core/shell structure with enclosed shell. Meanwhile,their saturation magnetization of increases while coercivity decreases. Finally a mixture of the prepared C/Co-composite with paraffin (50%, mass fraction) show excellent microwave absorption property i.e. a layer of such mixture of 2.5 mm in thickness exhibits a minimum reflection loss (RL) of -23 dB at 11 GHz ,and an effective bandwidth (RL<-10 dB) of 3 GHz. With the increase of layer thickness, the absorption peak shifts gradually to low frequencies and multiple-absorption peaks emerge. The excellent microwave absorption properties may be attributed to the better impedance matching, dielectric loss and quarter-wavelength interference cancellation etc..

The ferroelectric phase transition characteristics of the (Ba_0.84Ca_0.15Sr_0.01)(Ti_0.90Zr_0.09Sn_0.01)O₃ (BCSTZS) ceramics were investigated by the temperature-dependent Raman spectroscopy and electrical performance. The Raman active modes of the BCSTZS ceramics can be assigned as modes such as v₃(LO), v₃(TO), v₄(LO), v₂(LO,TO), v₁(TO) and v₁(LO). The modes of v₃(LO) and v₄(LO) disappear abruptly when the temperature extends beyond 80 °C, indicating that the phase structure of the BCSTZS ceramics transforms from tetragonal ferroelectric (FE_T) phase to cubic paraelectric (P_C) phase. The intensity and line width of Raman modes v₃(TO), v₂(LO,TO), v₁(TO) and v₁(LO) exhibit notably anomalous change around room temperature (20℃) and 80℃, showing the signal of FE_O-FE_T (O indicating the orthorhombic ferroelectric phase) and FE_T-P_C phase transitions. The existence of Raman active-modes, maximum strain and d₃₃^* values above the T_C temperatures indicates that the local polar micro-regions still retain in the cubic matrix phase. With the increase of temperature the resonant (f_r) and antiresonant (f_a) frequencies approach to each other, the f_a shows a discontinuous jump around T_C, and the maximum strain and large signal d₃₃^* values decrease gradually, proving further the occurrence of the ferroelectric phase transition.

Palladium and nitrogen co-doped TiO₂ films were prepared by DC magnetron sputtering and then characterized in terms of surface morphology, absorption spectra and photocatalytic reduction property under visible light etc.. The results show that the N-TiO₂ films are composed of anatase while they turn to be composed of rutile gradually due to the presence of Pd. After being co-doped with Pd, the films become loose with rougher surface. The introduction of Pd to N-TiO₂ thin films increases its effective absorption of visible light, as well as enhances its ability to capture electrons and separate photo-generated electron-hole pairs effectively. The photocatalytic reduction property of the films declines with the increasing Pd amount. Among others, the Pd-N-TiO₂ films with 0.4% (atomic fraction) Pd have the best photocatalytic reduction property.

Weld joints of low carbon steel Q235 was prepared by rotary friction welding technique, and the effect of friction time and forge pressure on the seaming ratio and metallurgical quality of weld joints was investigated. The results show that the tensile strength of the seaming zones prepared by the rotary friction welding with different welding parameters is greater than or equal to that of the base metal, in other word, the variation of welding parameters will simply affect the seaming ratio (the ratio of the length of seamed portion to the total length of a joint), while the quality of joints is direct determined by the seaming ratio. Further study shows that the seaming ratio increases with the forging pressure, but the increment slows down gradually and eventually reaches 100% when the forging pressure reaches a critical value. The axial shortening amount increases along with friction time, which then decreases the seaming ratio. The width of the weld zone becomes larger and the grain size increases with friction time. The grain size is not uniform near the weld seam with streamline structure presented. It is concluded that large forging pressure and short friction time are helpful to improve the seaming ratio, reduce the grain size and enhance the quality of the joints.

Nano-catalyst of (Co, N)/C has been successfully synthesized by solvothermal method using Co(Ac)₂, NH₃H₂O and nano-carbon powder as starting materials. The results show that the oxygen reduction reaction (ORR) activity of (Co, N)/C is better than that of single nitrogen-doped or cobalt-doped nano-carbon powder in terms of the onset potential (-0.08 V) and peak potential (-0.165 V), which is comparable to the commercial catalyst Pt-C. The electron-transferred number of (Co, N)/C for ORR is about 3.59, which is close to the first order reaction kinetics of ORR (n=4). The intermediate product of H₂O₂ produced from the ORR takes up about 25%. The (Co, N)/C catalyst also exhibits better methanol durability and stability comparing to the commercial Pt-C (20% Pt). Bonds of N-(C)₂, C-N-C and Co-C are the main active units of the catalyst and Co₃O₄ nano-particles can cooperatively improve the ability of catalyst.

Red phosphors SrMoO₄:Pr³⁺ have been successfully synthesized by hydrothermal method. Their crystal structure, morphology and photoluminescent property were characterized by means of X-ray diffractometer (XRD), field environmental scanning electron microscopy (FESEM) and photoluminescence (PL) spectroscopy. The results show that the phosphors synthesized are a single phase of SrMoO₄:Pr³⁺ with classical octahedral structure. The main excitation peaks are located at 450, 473 and 485 nm, respectively. The main emission peaks are located at 606, 625 and 650 nm, respectively. The phosphors exhibit a red performance at 650 nm, which are appropriate to the blue LED. The luminescent intensity of SrMoO₄:Pr³⁺ increases with the increasing doping amount of Pr³⁺. The luminescent intensity has the optimal value when x=0.02. However, the concentration quenching phenomenon appears when the doping amount of Pr³⁺ further increases. Under the excitation of 450 nm, the strongest emission peak emerged at 650 nm, corresponding to ³P₀→³F₂ transitions. The SrMoO₄:Pr³⁺ phosphors are promising red-emitting phosphors by blue excitation for white light emitting diodes.

Calcium titanite CaTiO₃ with dendrite structure were prepared by solvothermal method while adjusting the molar ratio of Ca/Ti. The microstructure and optical performance of the prepared CaTiO₃ were characterized by means of X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectrometer and UV-visible (UV-vis) spectrophotometer. The results show that Ca/Ti molar ratio has an important effect on the morphologies and phases of the prepared CaTiO₃. The morphology of the obtained CaTiO₃ changed from nano-sheets to aggregated prisms and then to butterfly-like dendrite structure with the increasing Ca/Ti molar ratio. The mechanism for the CaTiO₃ morphology changes was atributed to the transformation from the oriented self-assembly accompanied by Ostwald ripening to the diffusion-controlled process of “dissolution”. When Ca/Ti molar ratio is 1/2-1/1.5, the prepared CaTiO₃ is composed of nanosheets and aggregated irregular prisms. With the increase of Ca/Ti molar ratio, nanosheets transforms to irregular prisms. When Ca/Ti molar ratio is 1/1-1.2/1, the prepared CaTiO₃ exhibited mainly dendritic morphology, which was gradually developed with the increasing Ca/Ti molar ratio. When the Ca/Ti molar ratio rises to 1.25/1 and 2/1, the phases of Ca₃Ti₂O₇ and CaCO₃ appear due to the excess amount of Ca²⁺ ions in the solutions. When Ca/Ti molar ratio is 1.2/1, pure CaTiO₃ with dendrite structure, as a micrometer-scale structured material, showed the optimum value of 0.0187 min^-1 for the photocatalytic degradation, which is much convenient for storage and handling.

Monodispersed microspheres of melamine-formaldehyde (MF) was fabricated by polycondensation crosslinking process with aqueous solution of melamine and formaldehyde as raw material. Then the core-shell structure precursor of composite microspheres MF/Gd(OH)CO₃ was prepared by a urea-based homogeneous precipitation technique with MF microspheres as templates. Finally hollow microspheres of Gd₂O₃ were obtained by calcination of the MF/Gd(OH)CO₃ to remove tempaltes. The morphology and structure of the hollow microspheres Gd₂O₃ were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractomater (XRD), X-ray energy dispersive spectroscopy (XPS), thermal gravimetric analysis (TG) and differential scanning calorimetry (DSC). The results show that the MF templates can be effectively removed and the amorphous precursor of composite microspheres MF/Gd(OH)CO₃ has converted to crystalline Gd₂O₃ during the annealing progress. The generated hollow spheres of Gd₂O₃ possess particle size of about 2.4 μm and shell thickness of 120 nm.

As raw materials, expanded graphite (EG) sheets were prepared from natural graphite via intercalation-reduction method , while thermally reduced graphene sheets (T-rGO) and chemical reduced grapheme sheets (C-rGO) were prepared from graphene oxide (GO), which was synthesized by Hummers method. Then composites of polypropylene (PP)/graphite sheets were prepared with graphite sheets as fillers and PP as matrix by melt-blending method to produce composites of PP/EG, PP/T-rGO and PP/C-rGO respectively with different filler contents. The structure and properties of the three prepared composites of PP/graphite sheets are characterized by means of X-ray diffractormeter (XRD) , scanning electron microscope (SEM), thermal analysis (DSC), thermal gravimetric analysis (TGA), as well as tensile and impact tests. The results show that the tensile strength of composites of PP/EG and PP/T-rGO with 0.1% of EG or T-rGO, can reach 32.2 MPa and 33.5 MPa, which increased by 7.2% and 11.2%, respectively in comparison with that of the pure PP, while the impact strength of PP/EG and PP/T-rGO composites was improved by 27.4% and 19.6%. The tensile strength and impact strength of the composite PP/C-rGO with 0.3% C-rGO were 37.26 MPa and 37.26 kJ/m², respectively, which increased by 23.9% and 27%, in comparison with those of the pure PP. The melting temperatures, crystalline temperatures and crystalline degree of PP/graphite sheet composites were higher than those of the pure PP. In contrast to the pure PP, the melting temperature and crystalline degree of PP/C-rGO composites with 0.1% C-rGO increased 10.2^oC and 4.2%, respectively. It can be attributed to the "heterogeneous nucleation effect" of graphite sheets, which can induce the regular arrangement of PP molecular chains. The maximum decomposition temperatures of PP/EG, PP/T-rGO and PP/C-rGO composites with 0.1% of graphite sheet showed 13.5 ^oC, 9.1 ^oC and 6.9 ^oC respectively higher than that of the pure PP, indicating that the thermal stability of the composites can be improved by adding a small amount of graphite sheets. The fillers have been dispersed homogeneous in the matrix, but agglomeration appeared when excessive fillers were added.

Composites of hollow glass microspheres/epoxy resin were reinforced with carbon fibers (CF) of 1 mm and/or 2 mm in length, with mass fraction: 0.2%, 0.5%, 1% and 3% for the two fibers, respectively. The effect of the length and content of fibers on the flexural strength and flexural modulus, compressive strength and compressive elastic modulus of composites was investigated by three-point bending tester and compression testing. The experimental results show that the addition of carbon fibers of two different lengths can significantly improve the flexural and compressive properties of composite materials. The flexural strength and compressive strength of the composite increase firstly and then decrease with the increasing mass fraction of carbon fibers, which reach a maximum value when the fiber mass fraction is 0.5%, and then decrease with the increasing content of carbon fibers. When the length of carbon fiber is 1mm and the fiber mass fraction is 0.5%, the flexural strength increased by 198% and the compressive strength increased by 110% in contrast to that without addition of carbon fiber. When the length of carbon fiber is 1mm, the change of fiber content has great influence on the flexural strength, compressive strength and compressive modulus of the composite. However, when the length of carbon fiber is 2 mm the effect of the change of fiber content on the flexural strength and compressive strength of composites is a little.

The silica nanospheres were prepared by hydrolysis-condensation reaction of TEOS in isopropanol aqueous solution. Then the silica nanospheres were etched by sodium hydroxide under the protection of polyvinylpyrrolidone. The morphology and specific surface area of the synthetic silica nanospheres were tested by TEM and BET Nitrogen adsorption method, respectively. The model wastewater containing lead ion was used to investigate the adsorption properties and influencing factors of the prepared samples. The results show that the prepared silica have monodipersed porous spherical morphology with the specific surface area of larger than 600 m²/g, which can remove heavy metals in the wastewater efficiently.

Tadpoles-type POSS block copolymer with polystyrene block copolymer and polymethyl methacrylate as arms (PMMA-b-PS) was synthesized by atom transfer radical polymerization (ATRP) method with polysilsesquioxane (POSS) as the initiator and polystyrene block copolymer and polymethyl methacrylate as raw material, and then was characterized by means of FTIR, ¹H NMR and GPC. The results show that the tadpoles-type POSS block copolymer was synthesized successfully. Proton exchange membrane based on the tadpoles-type POSS type block copolymer was prepared, of which the ion exchange capacity, water uptake and swelling rate, proton conductivity and thermal performance was as sessed . The results show that proton exchange membrane based on the tadpole-type POSS block copolymer has higher proton conductivity at high temperature as well as high initial decomposition temperature and high temperature resistant performance.