2-吡嗪羧酸铜配合物的合成及其结构表征

Solvothermal reaction of 2-pyrazinic acid with Cu(SO₄)₂·5H₂O yields the title complex {[Cu₂(Pyz)₂(H₂O)₄]·SO₄}_n(1), which was characterized by elemental analysis, IR and single crystal X-ray diffraction structural analysis. The complex 1 crystallizes in Monoclinic system, space group P2₁/c, with lattice parameters a=1.126 87(6) nm, b=0.073 511(4) nm, c=1.185 06(7) nm, β=95.070(2)°, and V=0.977 83(9) nm³, Z=4, D_c=2.172 Mg·m^-3. CCDC: 692347.     

转型TP207树脂从低浓度稀土溶液中富集稀土的研究

为实现从低浓度稀土溶液中高效富集稀土,通过动态吸附-解吸试验,研究了转型TP207树脂吸附稀土的规律。系统考察了离子交换线速度、吸附液体积、初始p H值、铝离子对树脂吸附稀土容量的影响,以及解吸液体积对稀土解吸率的影响。结果表明：在稀土浓度为1.65g·L^-1,离子交换线速度为3 cm·min^-1,吸附液体积为7.50 L,初始p H值为3.46的条件下,TP207树脂对稀土吸附量Q_n1=0.18 g·g^-1;稀土溶液中铝和稀土存在竞争吸附,当Al³⁺浓度为0.35 g·L^-1时,TP207树脂对稀土吸附量Q_n2降为0.11 g·g^-1;采用5%的稀HCl对饱和树脂进行解吸,在解吸液体积为0.525 L时,稀土解吸率可达99.45%;树脂吸附稀土过程属于阳离子交换反应,符合Langmuir等温吸附模型,为单分子层吸附,树脂中C=O的O原子和C-N的N原子均参与配位反应。     

AN ALGORITHM OF UNCONSTRAINED MINIMIZATION WITHOUT DERIVATIVE AND ITS CONVERGENCE

In [1] the unconstrained minimization problem was considered and presented an algorithm without derivative. But the terminative conditions and convergence proof of the algorithm were not given. In this paper, we present a revised algorithm and prove its convergence.