Papers by Author: Hang Wang

Abstract: Translucent AlN ceramics were fabricated using spark plasma sintering (SPS) technique with 3wt% CaF2 as sintering additive. The samples achieved 52.4% maximum transmittance in medium IR region after 10 min holding time by spark plasma sintering at 1800°C and 30 MPa pressure in N2. The results from XRD, SEM, TEM and EDX showed that the sintered bodies were densely compacted and highly pure with fine grain size and uniform microstructures. No secondary phases were observed at the grain boundaries and triple grain junctions, which guaranteed good optical property of the sintered bodies.

Abstract: To investigate the mechanical property (shear strength, bending strength and compressive strength) and the interface combinative ability of the composite of bovine bone morphogenetic protein (bBMP) and porous hydroxyapatite (HA) with different pore diameter. HA1 (Φ100-300μm) and HA2 (Φ130-500μm) were used as carriers of bBMP(5mg). The 4 types material (HA1, HA2, bBMP /HA1, bBMP /HA2) were implanted into the femur of 10 dogs (2 dogs each group) for the shear test and 15 dogs (3 dogs each group) for the bending test and compressive test. The shear strength of all kinds of materials were increased as time went on and the shear strength of bBMP/HA1 was highest in four materials. The bending strength of bBMP /HA1 was close to the normal femur in the 24th week. The compressive strength of all materials was lower than the cortex of the dog’s femur until 24th week. The compressive strength of bBMP /HA1 was the highest in four types. The compressive strength of HA2 and bBMP /HA2 was decreased after implantation. Implant of bBMP /HA with 100-300μm diameter had strong bonding with the host bone, and had better mechanical properties than that with 130-500μm diameter. So the porous bBMP /HA (Φ100-300 μm ) could be a useful graft material due to its strength.

Abstract: Radix salvia miltiorrhiza is a commonly used herbal medicine in China, and tanshinone IIA is one of the major active ingredients. Nano Radix salvia miltiorrhiza particles were successfully prepared by high speed centrifugal sheering (HSCS) technology, and the prepared nanoparticles suspension was subsequently spray-dried. The different properties of nano particles and raw powder were systematically studied by laser light scattering granulometric analyzer, TEM, SEM and FTIR. The extractive quantity of tanshinone IIA was determined by high-performance liquid chromatography (HPLC). The results illustrate that raw Radix salvia miltiorrhiza powder can be ultrafinely ground to nanosize within 50min, and the molecular structure of active ingredients doesn’t change after being ground. Furthermore, the active ingredients can dissolve out directly and fully, and the extractive ratio of tanshinone IIA increases 28.6% by HSCS processing. It is valuable to combine nanotechnology and TCM to improve the bioavailability and rapid releasing.

Abstract: In this paper, we suggest PCH as a method of joining alloys. The temperature distribution in the samples during the joining process was analyzied. From the temperature distribution profiles in PCH joining, it is concluded that PCH for the joining has two advantages: (1) There is a temperature distribution peak along the sample. The contacting surfaces which need high temperature happen to obtain the highest temperature; (2) The parts to be joined at relatively lower temperatures can avoid the damage of heat attack. The optimal joining conditions were discussed. The PCH and HP techniques were compared for the joining of alloys. It was found that the high tensile strength joined structure of alloys can be fabricated by PCH method at lower joining temperature, shorter holding time, and lower pressure, compared with that by HP method. The PCH process was considered to be an eco-friendly process compared with the traditional heat diffusion joining methods.