聚胺与鲑鱼精DNA相互作用中的盐效应

通过浊度、紫外吸收和Zeta电位测定,研究了盐对聚胺与鲑鱼精DNA相互作用的影响。结果表明,加入盐产生屏蔽效应,使体系Zeta电位下降,当c(NaC l)=5 mmol/L时,SPM-DNA体系Zeta电位由0 mV降至-4mV,SPD-DNA体系电位由-2.5 mV降至-4 mV。浊度和紫外吸收结果证明了盐屏蔽效应的存在,并随盐浓度的升高,屏蔽效应增大,且Ca2+、Mg2+的屏蔽作用大于K+、Na+。pH的升高使聚胺-DNA的相互作用减弱。     

铁矿石预选工艺及设备发展前景

介绍了磁铁矿预选的重要性和必要性,详细分析了大块预选工艺、粗粒预选工艺、细粒预选工艺及红矿预选工艺及相关设备情况,并提出了一种新的破碎—预选工艺。分析认为:采用合理的预选工艺和生产设备是矿山节能降耗、降低生产成本的主要途径;同时针对铁矿石预选工艺及设备存在的问题和不足,提出了未来发展建议。     

荧光光谱与Zeta电位法研究十二烷基二甲基氧化胺与DNA的相互作用

通过荧光光谱与Zeta电位法研究了十二烷基二甲基氧化胺(DDAO)与鲑鱼精DNA的相互作用.非离子态DDAO胶束与DNA间存在弱的疏水相互作用.阳离子态DDAO与DNA的强烈静电相互作用导致体系荧光猝灭.胶束的形成有利于DNA构象的压缩与体系Zeta电位的提高.外加NaCl的静电屏蔽作用减弱了DDAO胶束与DNA间的静电引力.     

不同岩性条件下预应力锚索锚固力损失规律研究

There are many and complex factors that affect the anchoring effect of prestressed anchor cables, and each factor also affects each other. The loss of anchoring force is closely related to the properties of rock and soil. Through theoretical analysis, experimental research, numerical simulation, and other methods, the influence mechanism of creep deformation and compression deformation of rock and soil on anchoring force loss is studied. The law of prestressed anchor cable anchoring force loss caused by hard rock, weak rock, broken rock, and soil is studied. The research shows that the properties of rock and soil are different, The loss of anchoring force caused by prestressed anchor cables is also different: the better the quality of the rock and soil, the smaller the loss of anchoring force under the same initial anchoring force conditions. This research achievement can guide the design, construction, and operation management of anchoring engineering, which is beneficial for improving the economic and social benefits of anchoring engineering     

N,N-二甲基癸基氧化胺与鲑鱼精DNA相互作用的研究

通过浊度、紫外吸收和表面张力的测定,研究了N,N-二甲基癸基氧化胺(C10DAO)与鲑鱼精DNA的相互作用。结果表明:中性条件时C10DAO不能诱导DNA发生相分离;C10DAO浓度高于6.0 mmol/L的C10DAO-DNA体系达到临界pH时,静电相互作用导致体系浊度发生跃变;C10DAO浓度为6.0~16.0 mmol/L时,对应的临界pH改变显著。紫外吸收和表面张力结果也证实了相互作用的存在;荧光猝灭表明低质子化度的C10DAO可诱导DNA构象发生转变。