海洋生物质纤维材料的开发与研究

海洋生物质多糖拥有来源丰富可再生、可生物降解、快速的凝胶性能和良好的生物相容性等优异性能,被广泛应用作药物缓释、组织工程支架、医用敷料等领域,但国内外对于其在功能纤维的制备和应用等方面的研究尚处于初级阶段。结合本课题组已经取得的海洋生物质纤维制备的成果,本文对具有代表性的海洋生物质纤维材料——海藻酸盐纤维和卡拉胶纤维的...     

Coolant choice for the central beryllium pipe of the BESⅢ beam pipe

In order to take away much more heat on the BESⅢ beam pipe to guarantee the normal particle detection,EDM-1（oil No.1 for electric discharge machining）,with good thermal and flow properties was selected as the candidate coolant for the central beryllium pipe of the BESⅢ beam pipe.Its cooling character was studied and dynamic corrosion experiment was undertaken to examine its corrosion on beryllium.The experiment results show that EDM-1 would corrode the beryllium 19.9 μm in the depth in 10 years,which is weak and can be neglected.Finite element simulation and experiment research were taken to check the cooling capacity of EDM-1.The results show that EDM-1 can meet the cooling requirement of the central beryllium pipe.Now EDM-1 is being used to cool the central beryllium pipe of the BESⅢ beam pipe.     

微波协助下方便快捷的溴代芳烃均同偶联反应

芳香族的溴化物在钯催化剂和六丁基二锡存在下经过均同偶联反应能生成二联芳烃.该合成方法在微波协助下只需15min便可得到60%～84%的得率,具有方便、快捷、普适等特点.各种缺电子和富电子芳烃和杂环溴化物,如苯、噻吩、呋喃、吡啶、噻唑和嘧啶的溴化物均易偶联.此方法还适应于稠环芳烃如萘、喹啉、苯并噻吩和吲哚的溴化物,且与羟基、氨基、羧基、醛基、酰基、酯基、硝基、氰基等反应性基团相容.反应是通过溴代芳烃与六丁基二锡先原位生成芳烃有机锡,芳烃有机锡再与溴代芳烃发生Stille偶联反应进行的.