人工神经网络在轻板隔墙隔声预计中的应用

轻钢龙骨薄板墙(简称轻板隔墙)的隔声性能由于其构造的复杂性,没有简单公式可以预计其隔声量。在大量实验结果的基础上,利用人工神经网络对一些常见的轻板墙组合构造进行计权隔声量(RW)的预计。根据相关分析和主成份分析的结果,选用板材面密度、墙体总厚度、腔内吸声层厚度、龙骨型式和垫层等因子作为网络的输入变量,由此进行隔声性能的预计,可达到较满意的结果。     

新型双核铜金属配合物为中性载体的硫氰酸根离子高选择性电极的研究

研制了基于N,N'-亚乙基(μ-5,5-亚甲基-二水杨醛根)(乙酰丙酮根)合二铜(II) [Cu₂(II)-MDSBAE]金属配合物为中性载体的阴离子选择性电极. 试验表明, 以Cu₂(II)-MDSBAE金属配合物为中性载体的电极对SCN^－具有良好的电位响应特性, 且呈现反Hofmeister行为,其选择性序列为: SCN^－＞Sal^－＞I^－＞ClO₄^－＞NO₃^－＞Br^－＞NO₂^－＞Cl^－≈SO₃^2－＞SO₄^2－. 在pH 5.0的磷酸盐缓冲体系中, 电极电位呈现近能斯特响应, 线性响应范围为1.0×10^－6～1.0×10^－1 mol/L, 斜率为－53. 6 mV/dec (25 ℃), 检测下限为8.1×10^－7 mol/L. 用交流阻抗研究了电极的响应机理, 并用紫外可见光谱技术测定了电极载体与SCN^－, Sal^－, I^－, ClO₄^－和NO₃^－离子间的配位数及缔合常数. 将该电极用于实验室废水和工业废水中硫氰酸根的检测, 其结果令人满意.     

带次线性中立项的二阶广义Emden-Fowler微分方程的Philos型振动准则

研究一类带次线性中立项的二阶非线性广义Emden-Fowler时滞微分方程的振动性.利用Riccati变换和不等式技巧,在非正则条件下建立了该类方程多个简便的Philos型和Kamenev型新振动准则.所得定理也适应于包括经典Euler方程等线性非中立型方程,推广和改进了已有文献中的相应结果.最后还给出应用实例展示了所...     

基于物理中面FGM板屈曲的有限元分析

基于物理中面的概念,根据最小势能原理推导了功能梯度材料FGM薄板屈曲的有限元控制方程,求得临界荷载的有限元解。利用FGM板的屈曲方程与参考均匀板的屈曲方程之间的相似性,建立了FGM板的临界荷载与参考均匀板的临界荷载之间的相似转换关系式,从而将FGM板临界荷载的计算转变为参考均匀板的临界荷载和材料不均匀系数的计算,极大地提高了计算效率,为FGM的推广起积极的推动作用。通过数值算例,将由有限元法和转换关系式得到的临界荷载进行了比较,并讨论了边界条件、荷载工况、材料组成和几何尺寸等对FGM板临界荷载的影响。     

Implementation of a separate fluid-neutral energy equation in SOLPS-ITER and its impact on the validity range of advanced fluid-neutral models

In plasma edge transport codes for nuclear fusion devices, fluid-neutral models offer an interesting alternative to the currently used kinetic Monte Carlo simulations, especially for cases of high ion-neutral collisionality. In this paper, we elaborate a separate neutral energy equation in the state-of-the-art SOLPS-ITER code suite, which previously assumed perfect ion-neutral temperature equilibration. Furthermore, we study the coupled plasma-neutral solutions for a range of divertor operating regimes, proving the validity of these fluid-neutral models for high-recycling and detached regimes.     

Experimental studies on the effect of ultrasonic treatment and hydrogen donors on residual oil characteristics

Residual oil, the residue after the distillation of crude oil, imposes deleterious effects on refinery due to its high viscosity and asphaltene content. In this context, ultrasonic technology has been widely applied in refining processes given its high efficiency and minimal environmental impacts. To guide the selection of operation parameters, in this work, we probed the effect of treatment duration, power, and hydrogen donor on the characteristics of residual oil under ultrasonic treatments. Underlying mechanisms of ultrasonic treatments, in the absence and presence of hydrogen donors, were verified through systematically analyzing viscosity, component conversion, molecular weight, hydrogen distribution, and functional groups of residual oil. While viscosity reductions under low-power density treatment are caused by colloidal system disaggregation, high-power density treatment can bring in both chemical bond cleavage and colloidal system disaggregation. In addition, adding hydrogen donor can effectively prevent radical recombination, and thus increases the yield of saturate. These results provide fundamental understandings on the effects of ultrasonic treatments.     

Synthesis, Structure and Geometrical Calculation of a Novel Co-crystal of {[4-Bromo-2-(benzimidazol-2-yl)phenolato][2- (1-butylbenzimidazol-2-yl)phenolato]zinc(Ⅱ)] and Bis[μ-2- (1- butylbenzimidazol-2-yl)phenolato]- 1κN3: 2κO; 1κO:2κN3-bis{[2-(1-butylbenzimidazol-2-yl)phenolato-κ2N3,O]zinc(Ⅱ)}

The title compound has been synthesized and characterized crystallographically. It is a co-crystal consisting of two different neutral zinc(Ⅱ) complexes with Hbpbm (Hbpbm = 4-bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol).One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of[Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21·2.Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a= 15.0141(12), b = 20.9941(17), c =18.4686(15) (A), β = 97.445(2)°, V= 5772.4(8) (A)3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm3,μ = 1.579mm-1, F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I＞ 2σ(Ⅰ)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.     

Structure and Aromaticity of AlCO-substituted Semibullvalene

The structures, energies and aromaticity (the nuclear-independent chemical shifts, NICS) of AlCO-substituted semibullvalenes were investigated at the B3LYP/6-311+G** level. Similar to BCO-substituted analogues, [2,6]-AlCO-semibullvalene is neutral bishomoaromatic. The NICS values reveal that the aromaticity of AlCO-substituted structures is smaller than that of BCO analogues.     

聚中性红膜修饰电极测定痕量NO2^—的研究

研究了聚中性红膜修饰电极对ＮＯ－２的催化氧化性能，建立了测定ＮＯ－２的新方法。ＮＯ－２的浓度在２．０×１０－６～５．０×１０－３ｍｏｌ／Ｌ范围内与催化氧化峰电流呈良好的线性关系，检测限为６．０×１０－７ｍｏｌ／Ｌ。若利用计时电流法分析，检测限可达８．０×１０－８ｍｏｌ／Ｌ。     

聚中性红膜修饰电极的电化学特性及其电催化性能

研究了中性红在玻碳电极表面电聚合成膜的方法和条件，对膜内电荷传输过程和电化学特性分别用循环伏安技术和电位阶跃暂态技术进行了初步探讨。该膜对维生素Ｃ和亚硝酸盐有较强的电催化作用，催化电流与底物浓度在很宽的范围内呈线性关系，可用于实际样品的分析。