In the construction of Three Gorges Project, the total amount of concrete is about 28 Mm\+3 , and the total amount of metal works and reinforcement is approximately 0.72 Mt . The TGP is constructed in 3 stages . The p...In the construction of Three Gorges Project, the total amount of concrete is about 28 Mm\+3 , and the total amount of metal works and reinforcement is approximately 0.72 Mt . The TGP is constructed in 3 stages . The preparation period together with the first stage is 5 years , the second stage and third stage are both 6 years .In the second stage construction of 6 years (1998～2003) , there are 18.46 Mm\+3 of concrete to be placed and 0.192 Mt of metal works and embedded parts for mechanical and electric equipment to be installed . In 1999, a world record of annual concrete placement of 4.585 Mm\+3 was set . In 2000, it is planned to place 5.4 Mm\+3 of concrete and to install 38 000 t of metal works . Construction equipments and layout of construction site , concrete production and its temperature control, metal works, mechanical and electric equipments in the second stage construction are presented.展开更多
为减少食品和动物饲料加工过程中无机铜的使用和添加对环境的污染和营养物质的浪费,开发新型氨基酸铜制剂具有重要意义。本实验从食品级猪皮明胶中分离制备L-羟脯氨酸(L-Hyp),并以L-Hyp和Cu SO_4·5H_2O为原料,采用固相微波辐射和...为减少食品和动物饲料加工过程中无机铜的使用和添加对环境的污染和营养物质的浪费,开发新型氨基酸铜制剂具有重要意义。本实验从食品级猪皮明胶中分离制备L-羟脯氨酸(L-Hyp),并以L-Hyp和Cu SO_4·5H_2O为原料,采用固相微波辐射和加压二级处理的方法制备L-羟脯氨酸-Cu(Ⅱ)(L-Hyp-Cu(Ⅱ)),制备条件为:L-Hyp和Cu SO_4·5H_2O物质的量比2.5∶1,即10.5 g L-Hyp和8.0 g Cu SO_4·5H_2O充分混匀,加入引发水20 m L,微波功率600 W,添加除酸剂无水Na_2CO_3 5.6 g,微波时间180 s;二级加压处理,将微波辐射处理后的样品转入加压反应釜中,在二级反应温度90℃、二级反应压强15 MPa、搅拌速率100 r/min条件下,反应35 min。并用紫外光谱、红外光谱、X衍射、扫描电子显微镜、配合分析、元素分析、重量分析等手段对配合物的组成和结构进行表征。结果表明:经微波辐射和加压二级处理可以提高L-Hyp-Cu(Ⅱ)螯合率,产品螯合率为86.4%。通过表征分析发现,Cu(Ⅱ)与L-Hyp中的羧基和亚氨基发生配位,反应所得产物L-Hyp-Cu(Ⅱ)配位比为1∶2,分子式为Cu(C_5H_8NO_3)_2。展开更多
文摘In the construction of Three Gorges Project, the total amount of concrete is about 28 Mm\+3 , and the total amount of metal works and reinforcement is approximately 0.72 Mt . The TGP is constructed in 3 stages . The preparation period together with the first stage is 5 years , the second stage and third stage are both 6 years .In the second stage construction of 6 years (1998～2003) , there are 18.46 Mm\+3 of concrete to be placed and 0.192 Mt of metal works and embedded parts for mechanical and electric equipment to be installed . In 1999, a world record of annual concrete placement of 4.585 Mm\+3 was set . In 2000, it is planned to place 5.4 Mm\+3 of concrete and to install 38 000 t of metal works . Construction equipments and layout of construction site , concrete production and its temperature control, metal works, mechanical and electric equipments in the second stage construction are presented.
文摘为减少食品和动物饲料加工过程中无机铜的使用和添加对环境的污染和营养物质的浪费,开发新型氨基酸铜制剂具有重要意义。本实验从食品级猪皮明胶中分离制备L-羟脯氨酸(L-Hyp),并以L-Hyp和Cu SO_4·5H_2O为原料,采用固相微波辐射和加压二级处理的方法制备L-羟脯氨酸-Cu(Ⅱ)(L-Hyp-Cu(Ⅱ)),制备条件为:L-Hyp和Cu SO_4·5H_2O物质的量比2.5∶1,即10.5 g L-Hyp和8.0 g Cu SO_4·5H_2O充分混匀,加入引发水20 m L,微波功率600 W,添加除酸剂无水Na_2CO_3 5.6 g,微波时间180 s;二级加压处理,将微波辐射处理后的样品转入加压反应釜中,在二级反应温度90℃、二级反应压强15 MPa、搅拌速率100 r/min条件下,反应35 min。并用紫外光谱、红外光谱、X衍射、扫描电子显微镜、配合分析、元素分析、重量分析等手段对配合物的组成和结构进行表征。结果表明:经微波辐射和加压二级处理可以提高L-Hyp-Cu(Ⅱ)螯合率,产品螯合率为86.4%。通过表征分析发现,Cu(Ⅱ)与L-Hyp中的羧基和亚氨基发生配位,反应所得产物L-Hyp-Cu(Ⅱ)配位比为1∶2,分子式为Cu(C_5H_8NO_3)_2。
