A Novel 3D Supramolecular Framework of Poly[(5-(oxidediphenylphosphino)isophthalate)zinc(Ⅱ)]: Syntheses and Structure

A novel metal-organic framework, namely [Zn(C20H13O5P)]n(1), has been hydrothermally synthesized through the reaction of 5-(oxidediphenylphosphino)isophthalic acid(H2L) with Zn(Ⅱ) salt. The title compound crystallizes in monoclinic, space group P21/c with a = 11.0966(10), b = 14.5651(14), c = 14.7311(15), β = 130.022(6)o, C20H13O5 PZn, Mr = 429.64, V = 1823.3(3) 3, Dc = 1.565 g/cm3, F(000) = 872, μ = 1.463 mm-1, S = 1.054 and Z = 4. The final R = 0.0270 and wR = 0.0739 for 2769 observed reflections with I 2σ(I). In the title complex, the Zn2(CO2)2 binuclear clusters are linked by L2- ligands to result in a pillared layer structure in the bc plane, which is a(4,4)-net composed of helical chains with opposite chirality by sharing Zn2(CO2)2 units. Adjacent layers are further associated together through Zn–O bonds involving the metal center and the oxygen atom of P=O group to achieve a 3D architecture, in which one-dimensional quadrangled channel displays the interweaving of two pairs of coaxial double-helical chains with opposite chirality. The luminescence property and thermogravimetric analysis of the title complex were investigated.     

球形发射换能器多目标优化设计

为了解决球形发射换能器多约束条件下的离散/连续变量混合型非线性多目标优化问题,基于等效电路理论,建立了球形换能器的电学-力学-声学耦合模型,以辐射声源级、输入电功率和质量为优化目标函数,材料属性参数、结构尺寸参数、工作频率范围和输入电压为设计变量,压电陶瓷电退极化极限、结构强度极限、功率容量等物理特性以及设计变量取值等为约束条件,构建了球形换能器多目标优化数学模型;利用第二代非支配排序遗传算法(NSGA-Ⅱ)进行了球形换能器多目标优化设计,获得Pareto前沿解集;并通过实验验证了优化结果的有效性。结果表明,采用多目标优化方法设计和制作的球形发射换能器样机,在满足辐射声源级要求的前提下,工作频率范围内输入功率降低了32.8%,质量减轻了27.4%。研究结果可为严苛条件限制下的发射换能器优化设计提供参考。     

基于显热回收的分离式热管传热特性的实验研究

针对新风空调机组,采用倾角为15°的分离式热管用于显热回收.研究充液率,迎面风速及空气进口温度对显热效率的影响,分析了其影响规律.研究表明,采用热管空调机组设计风速范围内,充液率介于66％～75％时,其换热效率最高.迎面风速较低时,空气进口温度介于34℃～36℃,其显热效率较高.因此,采用分离式热管机组适合用于高热地区...     

BIN法建筑能耗快速计算——对称频数修正法

针对BIN能耗计算方法提出了一种更快的统计算法.BIN方法计算能耗将负荷表示为温度的线性关系,满足迭加原理.常数项部分对应的能耗用常数b乘以总频数即可;正比部分对应能耗用对称频数分布时的能耗乘以修正系数而得.给出了不同温度范围内实际温频数、对称分布的温频数以及修正系数.这种算法不用逐一求负荷然后逐一乘以对应的频数再求和,只需几步简单运算,能耗计算速度大大提高.     

Hydrothermal Synthesis and Crystal Structure of One 3D Coordination Polymer of Nickel(Ⅱ) Achieved from 5-Iodo-isophthalic Acid Ligand

A new coordination polymer [Ni(L)(m-bix)(H2O)]n(1, H2L = 5-iodo-isophthalic acid, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene) has been synthesized by the hydrothermal method and characterized by IR, elemental analysis, powder XRD and single-crystal X-ray analysis. The crystal is of triclinic, space group P1 with a = 9.1638(3), b = 10.2319(3), c = 13.2463(4) ?, α = 80.1710(10), β = 83.671(2), γ = 70.3790(10)o, C22H19NiIN4O5, Mr = 605.02, V = 1150.85(6) ?3, Dc = 1.746 g/cm3, F(000) = 600, μ = 2.225 mm-1, S = 1.045 and Z = 2. The final R = 0.0388 and wR = 0.1257 for 5089 observed reflections with I 2σ(I). In the title complex, the M and P layers are arranged alternately to give a double-layer structure by the symmetry related hydrogen bonds, and these double-layers are further joined together to achieve a 2D supramolecular architecture through I···π interaction involving iodine atoms and imidazole rings. The thermal stability of the title complex was studied by thermal gravimetric(TG) and differential thermal analysis(DTA).