Tooth-locked quick-opening pressure vessel is widely used. The fast opening structure was an important part of the pressure vessel door opening and closing operation and the meshing degree of the tooth determined the safe of the container's operation. A tooth-meshing autoclave was taken as an example and the finite element analysis was used as a method to carry on the numerical simulation to its meshing tooth in load condition and the strength check to its dangerous path. In the case of the incomplete meshing in the circumferential direction, the incomplete meshing in the radial direction and the combined operation in which the two directions were not fully meshed. According to the analysis results, it could be seen that with the decrease of meshing tooth circumferential or radial meshing degree, the stress increased. Under the dangerous working condition of combined meshing (i.e.circumferential meshing degree was 80%, radial dislocation was 3.0 mm)，the tooth's stress reached the maximum. After the strength check, the primary local membrane stress exceeded the allowable value, so the stress didn't meet the requirements. According to the analysis results, the quick-opening container should be avoided to working with incomplete meshing tooth to ensure the safe use.

The Keggintype phosphotungstovanadic heteropolyacid catalyst was synthesis by N a 2HP O4、 N a VO3  and N a 2WO4·2H2O. Then,H4PW1 1VO4 0 heteropolyacid hybrid materials was prepared by reacting H3PMo12O40 with 1butyl3methylimidazolium bromide ionic liquid. The prepared catalyst was characterized by XRD and IR, and the results showed a characteristic Keggintype structure of 4PW1 1VO4 0/ S i O2,以 H2O2  catalyst was prepared using SiO2 as the support. The suppoted catalyst was then applied as catalyst for the degradation of Rhodamine B using the H2O2 as the oxidant. The obtained optimal reaction conditions was 3 mL of H2O2, the weight of 4PW11VO40 20% loading, 0.35 g of catalyst at 40 ℃ for 1.5 h. Under the optimal condition, the degradation rate of Rhodamine B was up to 98.4%. The catalyst shoed good reusability and can be reused for many times without the decrease of degradation activity of Rhodamine B .

Gd ₂O ₂S:Dy ³⁺  phosphors were synthesized by a homogeneous precipitation method from Gd ₂O ₃, Dy ₂O ₃, H ₂SO ₄ and Urea starting materials. The characterizations of Gd ₂O ₂S:Dy ³⁺  phosphors were investigated by means of XRD, FE-SEM and PL spectra. XRD analysis shows that the precursor can be transformed into pure Gd ₂O ₂S powder by calcining at 900 ℃ for 1 h in hydrogen. FE-SEM observation shows that the Gd ₂O ₂S powder particles are quasi-spherical in shape, with a mean particle size of about 300~500 nm. Photoluminescence (PL) spectroscopy reveals that the main and second emission peaks are located at 579 nm and 488 nm under 270 nm UV light excitation, which corresponds to the  ⁴ F _9/2→ ⁶H _13/2 and the ⁴F _9/2→ ⁶H _15/2 transitions of Dy ³⁺ ions, and both transitions of Dy ³⁺ ions have a single exponential decay behavior. The quenching concentration of Dy ³⁺ ions is 1 %. The CIE coordinate and the color temperature of (Gd _0.99,Dy _0.01) ₂ O ₂S phosphor are (0.308, 0.379, 0.313）and 6 464 K respectively.

The microstructure of pearlite spheroidized 20g steel during tensile deformation was investigated with field metalloscope. SEM images of the specimen were taken after deformation. The results show that during tensile deformation, pearlite spheroidized 20g steel got deformed in some of its grains. It causes a large amount of glide bands, and piles-up at the grain boundary. Some of other grains start to deform, which form favorable orientation in order to complete further deformation. During tensile deformation, microcracks generate at the pearlite on the edge of the specimen. Microscopic voids generated at the ferrite and pearlite grain boundary inside the specimen, then extend and connect to microcracks, it shows as transcrystalline and intercrystalline fracture.

 

The 400 MPa ultrafine grained steel strip with thickness of 8 mm was connected by CO2+Ar arc welding under single-pass welding and double-pass welding, and the low-temperature toughness for weld joints was investigated by series impact test. The experimental results show that the low-temperature toughness for weld is worse among the weld joint. The low-temperature toughness for weld joint by double-pass welding is better than that of single-pass welding, and its heat affected zone(HAZ) is decreased because smaller heat input reduces grain growth coarsening.