六氟环氧丙烷的合成

介绍了六氟环氧丙烷的性质、用途及其制备方法,并对其几种制备方法进行了比较.     

一氯二氟醋酸的合成和应用

一氯二氟醋酸是一典型的含氟化学品,本文对其性质、合成方法和应用进行介绍.     

中国岩溶地面塌陷及防治

根据大量资料和试验对中国岩溶塌陷的成因类型和机理提出了新的看法,对近代岩溶塌陷提出了自然充气防塌法并已取得良好效果。     

六氟丁醇的制备和应用

六氟丁醇（HFB）是一种十分有用的含氟醇，有着广泛的应用前景。六氟丁醇（２，２，３，４，４，４－Hexafluorobutanol－１；Hexafluorobutanol），结构式：CF３CFHCF２CH２OH，分子式：C４H４F６O，分子量：１８２．０６，CAS号：３８２—３１—０。六氟丁醇为淡黄色液体，密度（２５℃）：１．５４g／cm３，沸点：１１４℃（１０１．３kPa），闪点：５１℃；室温时的饱和蒸汽压：１０mmHg；折射率nD２５：１．３１４１；粘度（２０℃）：４．４cs；易燃、有毒，LD５０：９５０mg／kg。１六氟丁醇的应用１．１作溶剂六氟丁醇…     

Properties of Magnetite Nanoparticles Produced by Magnetotactic Bacteria

The magnetic nanoparticles(magnetite) were prepared through the fermentation of the Magnetospirillum strain WM-1 newly isolated by our group. The samples were characterized by TEM, SAED, XRD, rock magnetic analysis, and Mossbauer spectroscopy. TEM and SAED measurements showed that the magnetosomes formed by strain WM-1 were single crystallites of high perfection with a cubic spinel structure of magnetite. X-ray measurements also fitted very well with standard Fe3O4 reflections with an inverse spinel structure of the magnetite core. The size of crystal as calculated by the Debye-Scherrer's equation was approximately 55 nm. Rock magnetic analysis showed WM-1 synthesized single-domain magnetite magnetosomes, which were arranged in the form of linear chain. The high delta ratio((δFC / δZFC = 4) supported the criteria of Moskowitz test that there were intact magnetosomes chains in cells. The Verwey transition occurred at 105 K that closed to stoochiometric magnetite in composition. These observations provided useful insights into the biomineralization of magnetosomes and properties of M. WM-1 and potential application of biogenic magnetite in biomaterials and biomagnetism.     

Dynamic mechanical property of hybrid fiber reinforced concrete(HFRC)

The uniaxial compressive response of steel-polypropylene hybrid fiber reinforced concrete(HFRC) and steel fiber-reinforced concrete(SFRC) was analyzed under high strain rate loading with a 74 mm diameter split Hopkinson pressure bar(SHPB).The experimental investigation focused on recorded data and resulted in distinguishing the strain rate that mobilized different ductility of steel-polypropylene hybrid fiber reinforced concrete(HFRC) and steel fiber-reinforced concrete(SFRC).64 specimens of HFRC and SFRC with higher static compressive strength were tested at the strain rates changing from 20 to 120 s-1.The static compressive strength and dynamic stress-strain curves of the two materials were obtained at 4 different strain rates and the failure stress,and peak strain and peak toughness were also analyzed.The results show that HFRC has quite good dynamic mechanical property and clear strain-rate effect,and the failure mechanism of HFRC and SFRC was also compared based on the specimens’ failure modes in static and dynamic compressive tests.     

中国国际贸易中心三期主塔楼结构设计

位于中国北京的中国国际贸易中心三期主塔楼高330米,包括一座五星级酒店和甲级写字楼。建筑物的高度和北京的高抗震烈度设计对于结构设计师都是一个挑战,特别是考虑到中国规范中各项严格的要求。在结构设计过程中,各种结构类型及不同材料的使用都经过讨论研究。最终的结构体系是一个组合支撑框架核心筒和组合周边刚性框架筒,在机电层再辅以伸臂桁架连接两个筒。由于塔楼外立面宽度逐渐收小,结构上采用了三层腰桁架,而在腰桁架之间柱子的数量逐渐减少。塔楼的底部是八层高带转换桁架的V型柱,以符合建筑上对五星级酒店和甲级写字楼首层宏大的主入口的要求,同时又可平缓地过渡到上部的抗弯刚架。结构体系中根据不同的部位相对采用了各种类型的组合构件来满足刚度、延性、冗余度并达到最好的性能价格比。组合钢板墙(C-SPW)可能是首次在中国的结构中应用,以增加剪力墙的抗剪承载力和刚度,并改善延性。结构设计中运用了精确的有限元分析及先进的非线性弹塑性时程分析来评估结构的性能及确保建筑物在不同地震水准下的安全性。     

2-溴-3,3,3-三氟丙烯的制备

以3,3,3-三氟丙烯和溴为原料,经加成反应合成了中间产物1,2-二溴-3,3,3-三氟丙烷,随后在氢氧化钠水溶液中进行消除反应制备了目标产物2-溴-3,3,3-三氟丙烯,通过试验得到了较佳的反应条件。     

“黑灯库房”在山钢冷轧厂的实现与应用

针对当前轧钢企业智能工厂及智能物流的建设,介绍了“黑灯库房”在山钢日照公司冷轧厂轧后库和成品库的应用情况;主要对无人行车的硬件组成及关键技术,如防碰撞技术、智能扫描定位系统、吊具防摇摆技术、智能吊具系统等,进行了详细阐述,并对库管系统及其功能进行了介绍。实际应用表明,采用“黑灯库房”不仅能够带来良好的经济效益,而且库存周转更快、更高效,在安全上提供了更强有力的保障,使山钢日照公司智能制造水平有了较大提升,为下一步智能梦工厂的实现打下了良好的基础。     

参数化和生成式风景园林设计 以清华建筑学院研究生设计课程作业为例

复杂系统和非线性科学将世界看作是由大量个体相互联系组成的动态系统。基于计算机技术的参数化和生成式设计方法在这种新的科学体系和世界观的影响下产生。风景园林作为自然生态系统的一部分,具备了复杂系统的特征,因此,在设计中运用参数化和生成式设计方法具有其独特的合理性和意义。针对这一议题进行了分析,并以研究生设计课的学生作品为例,展示了在参数化和生成式风景园林设计理念和方法上的最新的教学成果。