酸性镀铜液中Cl^—离子的作用机理研究

用电化学测量、Ｘ射线衍射和Ｘ射线电子能谱等方法研究酸性镀铜液中Ｃｌ＾－离子的作用机理。结果表明：镀液中Ｃｌ＾－离子加速Ｃｕ＾２＋离子的放电反应并使后者按两个单电子步骤进行；Ｘ射线衍射结果表明铜沉积层呈立方结构Ｃｕ，也包含立方结构ＣｕＣｌ；ＸＰＳ谱观察到两个ＣｕＣｌ特征谱峰，Ｃｕ电沉积层中含有ＣｕＣｌ导致其电化学活性降低。     

公安通信保障技术实训教学体系研究

公安通信保障技术实训教学采用模拟警务实战的方式,完成了公安通信保障技术的实训教学方案,设计出与公安实战工作紧密结合的实训教学体系,有利于培养学生的警务专业技能。实训方案探讨程控交换机的实际操作、系统维护及故障检查,加入了更加贴近公安实战探索和创新方法,并给予学生充分的自主设计空间,学生自愿组合,自己设计方案,整体研究方案符合公安信息化建设整体思路,缩短教学与警务实战的差距。     

Effect of Media on the in vitro Degradation of Biodegradable Ureteral Stent

The biodegradable ureteral stent should retain their supporting properties for defined period and then gradually degrade to small particles with the flow of urine. The mechanism and process of the stent’s degradation should be investigated and understood well due to its direct impact on the stents’ usage. An enhanced braidbased degradable ureteral stent composed of poly-glycolic acid(PGA) and the copolymer of lactic and glycolic acid(PGLA) was evaluated in vitro in this study with four kinds of degradable media:human urine(HU,pH = 7. 4),artificial urine(AU,pH = 5. 8),and phosphate buffer solutions( PBS,pH = 5. 8 and 7. 4) so as to compare the effects of media on the degradation of stents. The mechanical properties and morphology were observed at different degradaing time intervals of 0,7,14,21,28,and 35 d. The in vitro degradation behaviors of stents in four kinds of media were extremely different. The degradation rate of stents in HU was the highest. The impact of media’s pH to the degradation is not obvious while the components in the media contribute much to the difference.     

Properties of Scaffold Reinforcement for Tendon Tissue Engineering in vitro Degradation

Four kinds of braided yarns were produced with different proportions of polyglycolic acid( PGA) and polylactic acid( PLA)multifilaments( 2PGA /1PLA, 2PGA /2PLA, 3PGA /1PLA, and3PGA /2PLA). A novel artificial plain stitch scaffold reinforcement was manufactured by braiding technology and knitting technology respectively. Tendon scaffold reinforcements were investigated for 8weeks in phosphate buffered solution( PBS)( pH = 7. 4) at 37 ℃.The degradation was studied with regard to the mass loss,tensile properties,grams per square meter( g /m2),thickness,caliber,and porosity of scaffold reinforcements. The experimental showed that during the process of 8-week degradation,the mass losses of scaffold reinforcements were small in the first 3-week,but they increased rapidly after 3-week,and the speeds tended to be small gradually after 6-week; the tensile properties dropped rapidly in the first 2-week; the grams per square meter and thicknesses speeded down obviously between 3-week to 6-week. The caliber and porosity of scaffold reinforcements first decreased and then increased gradually. The porosity can reach more than 97%.