微波辅助酶解-超高效液相色谱串联质谱联用法快速检测尿液中的1-羟基芘

 利用微波辅助酶解结合超高效液相色谱串联质谱联用法,建立了人体尿液中1-羟基芘的快速检测方法.通过对比酶解与碱解、恒温水浴酶解与微波辅助酶解、液液萃取与固相萃取等前处理方法对1-羟基芘检测的影响,最终采用微波辅助酶解、固相萃取作为样品检测的前处理方法.考察了基质效应,对比了纯溶剂与空白尿液配标准溶液2种不同的标准溶液配制方法,最终选用空白尿液来配制.方法的标准曲线方程为y=1.24107x-0.130042,相关系数为0.9972,样品回收率在88.6%～97.1%之间,相对标准偏差在2.7%～12.6%之间,日内精密度为6.1%,日间精密度为6.2%,方法检测限为0.08ng/mL,定量限为0.28ng/mL.     

离子色谱法测定烟草种植用有机肥中4种阴离子

氮是影响烟草生长快慢、叶片大小以及产量的关键因素,氮还是烟碱的组成成分,对烟叶香气组成、吸味及刺激性均有重要作用;磷可以促进细胞分裂,提高烟株抗旱性能,施用磷肥过多,烟株暴长、叶片厚、组织粗糙,烤出的烟叶弹性较差、油分少、不利于回软;用量不足,烟株根系生长发育不好、成熟期推迟;硫不是叶绿素的成分,但影响叶绿素的合成;     

Tunneling dynamics of superfluid Fermi gas in a triple-well potential

The tunneling dynamics of superfluid Fermi gas in a triple-well potential in the unitarity regime is investigated in the present paper. The fixed points of the (0, 0) mode and the (∏, ∏) mode are given. We find that the interaction parameter U and the coupling strength k could have an extreme effect on the quantum tunneling dynamics. We also find that, in the zero mode, only Josophson oscillation appears. However, for the ∏ mode, the trapping phenomena take place. An irregular oscillation of the particle number in each well could appear by adjusting the scanning period T* . It is noted that if the scanning period is less than a critical point T , the particle number will come back to the fixed point with small oscillation, while if T T* the particle number cannot come back to the fixed point, but with irregular oscillations. The dependence of the critical point T* on the system parameter of coupling strength k is numerically given.     

ON DE FINETTI'S OPTIMAL IMPULSE DIVIDEND CONTROL PROBLEM UNDER CHAPTER 11 BANKRUPTCY

Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow [44] to revisit the De Finetti dividend control problem under the reorganization process and the regulator’s intervention documented in U.S.Chapter 11 bankruptcy.We do this by further accommodating the fixed transaction costs on dividends to imitate the real-world procedure of dividend payments.Incorporating the fixed transaction costs transfor...