电芬顿降解苯乙酮过程中有机物三维荧光特征的变化规律

采用荧光光谱技术检测分析了苯乙酮在电芬顿处理过程中的三维荧光光谱特征变化规律,研究了苯乙酮的三维荧光特征及其指纹特征,对苯乙酮去除率和荧光峰强度变化进行线性拟合研究.结果表明,苯乙酮具有两个荧光峰,分别在λEx/Em=270/305 nm(Peak A)和λEx/Em=215/305 nm(Peak B)处,且荧光指纹...     

纳米三氧化钨的制备、表征及对六硝基六氮杂异伍兹烷热分解的影响

采用水热法通过控制前躯体钨酸钠的加入量和反应时间制备了长方体形纳米WO₃,利用X射线粉末衍射(XRD)、透射电镜(TEM)、扫描电镜及能量散射光谱仪(SEM-EDS)对样品进行表征。并运用差示扫描量热法(DSC)研究纳米WO₃对六硝基六氮杂异伍兹烷(CL-20)热分解特性的影响。结果表明:与单组分CL-20相比,纳米WO₃的加入使复合物WO₃/CL-20的热分解峰温降低2.95℃,活化能减小7.74 kJ·mol^-1,因此纳米WO₃能够加速CL-20的热分解。     

Wronskian,Gramian, Pfaffian and periodic-wave solutions for a (3+1)-dimensional generalized nonlinear evolution equation arising in the shallow water waves

Application of the shallow water waves in environmental engineering and hydraulic engineering is seen. In this paper, a (3+1)-dimensional generalized nonlinear evolution equation (gNLEE) for the shallow water waves is investigated. The Nth-order Wronskian, Gramian and Pfaffian solutions are proved, where N is a positive integer. Soliton solutions are constructed from the Nth-order Wronskian, Gramian and Pfaffian solutions. Moreover, we analyze the second-order solitons with the influence of the coefficients in the equation and illustrate them with graphs. Through the Hirota-Riemann method, one-periodic-wave solutions are derived. Relationship between the one-periodic-wave solutions and one-soliton solutions is investigated, which shows that the one-periodic-wave solutions can approach to the one-soliton solutions under certain conditions. We reduce the (3+1)-dimensional gNLEE to a two-dimensional planar dynamic system. Based on the qualitative analysis, we give the phase portraits of the dynamic system.

     

A convergent and stereocontrolled cycloaddition strategy toward eudesmane sesquiterpenoid: total synthesis of (±)-6β,14-epoxyeudesm-4(15)-en-1β-ol

We present in this report the development of a convergent and highly stereocontrolled cycloaddition strategy toward the synthesis of C-1, C-6, and C-14 tris-oxygenated eudesmane sesquiterpenoids. This approach was demonstrated in the first total synthesis of (±)-6β,14-epoxyeudesm-4(15)-en-1β-ol (1), a structurally unique ethereal eudesmane sesquiterpenoid, via an effective Diels-Alder construction of a compact functionalized tricycle intermediate from readily available N-benzylfurfurylamine (2) and homoprenyl maleic anhydride (3) as the C(5) and C(10) building blocks, respectively.