Dali ZHOU
,
Weizhong YANG
,
Guangfu YIN
,
Changqiong ZHENG
,
Yun ZHANG
,
Huaiqing CHEN
,
Rui CHEN
材料科学技术（英文）
To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissue engineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solvent casting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behavior of the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP, the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporated into the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold were determined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Results show that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strength needed for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility and osteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation and osteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It is expected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.
关键词:
β-tricalcium phosphate (β-TCP)
,
null
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms
A static Monte Carlo simulation program has been used to study the influence of primary and secondary knock-on atoms on the angular distribution and the fractionation, for zero-fluence sputtering of Mo-92-Mo-100. At 10 keV Xe ion energy, calculations show that significant depth-dependent momentum asymmetry exists in the near-surface region, as in Refs. (L.P. Zheng, R.S. Li, M.Y.LI, Nucl. Instr, and Meth. B 100 (1995) 490; L.P. Zheng, M.Y. Li, Nucl. Instr. and Meth. B 114(1996) 28). The calculations also show that at the polar emission angle range between 0 degrees and 90 degrees the probabilities of the sputtered primary knock-on atoms for Mo-92 and Mo-100 are small (6.1% for Mo-92 and 6.6% for Mo-100), especially, between 0 degrees and 30 degrees they are very small (2.5% for Mo-92 and 2.8% for Mo-100). At 0.1 keV Ar ion energy, the calculations show that partial momentum flux ratios, for the primary and the secondary knock-on atoms, deviate far from one, through marker plane 1 (about an atomic layer distance from the surface). (C) 1998 Elsevier Science B.V. All rights reserved.
关键词:
mo-92-mo-100;targets
李红
,
孙克
,
李艳萍
,
石毅
,
郭金花
,
卢志超
金属功能材料
提出了采用推杆式热膨胀仪测试非晶合金薄带热膨胀特性的新方法.分析了Fe80Si9B11非晶薄带的热膨胀曲特性和非晶合金晶化过程.根据R.G.Zheng理论分析了结构弛豫中自由体积比变化,发现自由体积比曲线出现双峰.结合晶化前发生相分离的理论分析了这种变化的原因.分析表明:铁基非晶Fe80Si9B11晶化过程中先形成α-Fe(Si)相,再析出Fe3B、二次α-Fe(Si)相.晶化前先发生相分离,自由体积比增大,然后析出结晶相α-Fe(Si),自由体积比降低.随温度升高,B偏聚,自由体积比增大,随后析出Fe3B、二次α-Fe(Si)相,自由体积比降低.
关键词:
铁基非晶薄带
,
热膨胀系数
,
自由体积比
,
结构弛豫
