Search

The low-alloy steel matrix composites locally reinforced with in situ TiC particulates have been successfully produced utilizing the self-propagating high-temperature synthesis (SHS) reaction of (Ti, Fe)-C systems during casting. Two types of TiC particulates synthesized by different mechanisms exhibit a relatively uniform distribution in the local reinforcing region. The large rectangular TiC particulates with an average size of ∼2μm or more, which are formed by the nucleation-growth mechanism through the contact reaction process, are mainly present in the local reinforcing region of the composites fabricated by (28Ti, Fe)-C system and the matrix region nearby the interface between the steel matrix and reinforcing region. The fine spherical/near-spherical TiC particulates, which are synthesized by reaction, solution and precipitation mechanism during the SHS reaction, are mainly existent in the reinforcing region. Moreover, the average size of spherical/near-spherical TiC particulates increases from ∼0.1 to ∼0.5, and then to ∼1 μm with the increase in Ti content from 28 to 48, and then to 68wt% in (Ti, Fe) powders. The interfaces of the composites are clean, which results in a good metallurgical bonding between steel matrix and reinforcing region in the composites. Moreover, the micro-hardness and wear resistance of the local reinforcing region of the composites are significantly higher than those of the unreinforced steel matrix.

To investigate the timing changes of apoptosis (APO) and PCNA after intra-arterial infusion chemotherapy for nasopharyngeal carcinoma.Ten patients were subjected to percutaneous superficial temporal artery catheterization and infusion of anticancer drugs: 5-Fu, DDp, BLM, nicotinamide. The biopsy of nasopharyngeal tumor tissues was performed before chemotherapy and 7 days after chemotherapy. Apoptotic cells were examined by TOT-mediated DUTP-fluorescein and labeling. The expression of proliferating cells nuclear antigen (PCNA) was detected with immunohistochemical staining.AI of nasopharyngeal cancer cells before chemotherapy and 7 days after chemotherapy was 0.52% and 1.42%, PI was 42.4% and 51.2%.Intra-arterial infusion chemotherapy not only induced apoptosis effectively, but also inhibited temporarily tumor cells proliferation in patients. The curative surgical treatment should be performed as soon as possible after chemotherapy.

Melt of La68Al10Cu20Co2 alloy was solidified by rapid compression within 20msto5.5GPa at 733K. The structural analysis demonstrates that the recovered alloy is a fully glassy structure indicating that the method is an effective way for preparing bulk metallic glass. Differential scanning calorimetry analysis indicates the glass-forming ability of the alloy is enhanced according to the reduced glass transition temperature. It is found that exist markedly differences in thermodynamic and mechanical properties between the metallic glasses prepared by melt quenching and rapid compression.