How the Influence of Different Salts on Interfacial Properties of Surfactant–Oil–Water Systems at Optimum Formulation Matches the Hofmeister Series Ranking

In this work, we present the effects of salts on sodium dodecyl benzene sulfonate micellization and on the interfacial performance of a sodium dodecyl benzene sulfonate–heptane–brine system at optimum formulation, i.e., hydrophilic–lipophilic deviation (HLD) = 0. In order to do that, interfacial tension and dilational interfacial rheology properties of surfactant–heptane–water systems at optimum formulation are measured using an interfacial spinning drop tensiometer with an oscillating velocity, which can accurately measure interfacial rheology properties at both low and ultralow interfacial tensions. The brines used contain one of the following salts: MgCl₂, CaCl₂, NaCl, NH₄Cl, NaNO₃, CH₃COONa, or Na₂SO₄. We performed a one-dimensional salinity scan with each of these salts to achieve an optimum formulation. In relation to the Hofmeister series, we found that, at optimum formulation, systems with chaotropic ions (NH₄⁺, NO₃⁻) present interfaces with ultralow interfacial tensions, very low dilational modulus, and a low phase angle, whereas kosmotropic ions (Mg²⁺, Ca²⁺, SO₄⁻²) generate high interfacial tension and high rigidity monolayers. Intermediate ions in the Hofmeister series (Na⁺, CH₃COO⁻, Cl⁻) present interfaces with intermediate properties. Furthermore, according to the Hofmeister series, interfaces can be respectively ordered from higher to lower rigidity for surfactant counterions Mg²⁺ > Ca²⁺ > Na⁺ > NH₄⁺ and coions SO₄²⁻ > CH₃COO^– > Cl⁻ > NO₃⁻, which correspond to a salting-out (highest rigidity) and salting-in (lowest rigidity) effect. We observed that counterions have a more significant effect on surfactant–oil–water system properties than those that act as coions.     

Co-doping effects of (Al,Ti, Mg) on the microstructure and electrical behavior of ZnO-based ceramics

Co-doped ZnO-based ceramics using Al, Ti, and Mg ions in different ratios were synthesized with the objective to investigate the doping effects on the crystalline features, microstructure and the electrical behavior. For Al and Ti doping, a coexistence of crystalline phases was shown with a major wurtzite ZnO structure and secondary spinel phases (ZnAl₂O₄, Zn₂TiO₄, or Zn_aTi_bAl_cO_d), while Mg doping did not alter significantly the structural features of the wurtzite ZnO phase. The electrical behavior induced by Al, Ti, and Mg co-doping in different ratios was investigated using Raman, electron paramagnetic resonance (EPR) and ²⁷Al and ⁶⁷Zn solid-state nuclear magnetic resonance (NMR). Al doping induces a high electrical conductivity compared to other doping elements. In particular, shallow donors from Zn_i-Al_Zn defect structures are inferred from the characteristic NMR signal at about 185 ppm; that is, quite far from the usual oxygen coordinated Al. The Knight shift effect emanating from a highly conducting Al-doped ZnO ceramics was considered as the origin of this observation. Oppositely, as Ti doping leads to the formation of secondary spinel phases, EPR analysis shows a high concentration of Ti³⁺ ions which limit the electrical conductivity. The correlation between the structural features at the local order, the involved defects and the electrical behavior as function of the doping process are discussed.     

单片机在H^＋—ISFET PH计中的应用

本文是单片机氢离子敏场效应管pH计的研制总结。文中论述了把单片机应用于氢离子敏场效应管pH计中的数学模型和实现方法,以及软件、硬件的组成方式等。     

柱承式贮(群)仓在水平地震作用下的扭转效应

文章引入扭转效应系数的概念,根据群仓平移—扭转耦联振动微分方程,应用反应谱振型分解法,导出了群仓周期扭转效应系数和支柱内力扭转效应系数的解析公式。经过分析简化,找出了主要控制参数,提出了考虑群仓的地震扭转效应时,支柱地震内力的工程算法,并给出了工程设计用数值计算表。     

GPC的浓度效应

本实验用东洋曹达 HLC-802A GPC 仪考察了几种窄分布聚苯乙烯样品和两种宽分布聚苯乙烯样品.结果表明:(1)在0.10～0.15g/100ml 浓度以下几乎没有浓度效应.(2)浓度再增加,淋洗体积随之增加。(3)分子量随浓度增加而降低,且峰加宽.(4)分子量大者,浓度效应显著.窄分布样品比宽分布样品明显.(5)流速大,浓度效应显著.     

新型光学耦合器——梯度折射率透镜

本文用三种方法研究了钛扩散铌酸锂平面光波导与阶跃型多模光纤的耦合.通过测量的数据及理论分析计算,提出了一种新的最佳的光学耦合方法,可改善能量在光纤中的傅输性能,提高耦合效率     

Fabrication and properties of multistage gradient doping Yb:YAG laser ceramics

In order to fully pump and smoothen the temperature gradient of the gain medium, multistage gradient doping Yb:YAG laser ceramics were designed. The composite green bodies were fabricated by tape casting, and multistage gradient doping Yb:YAG ceramics with high optical quality were prepared by vacuum sintering and hot isostatic pressing. For samples pre-sintered at 1740°C for 30 h and then HIP-ed at 1700°C for 3 h in argon at 200 MPa, the in-line transmission values at 1100 nm of YAG, 0.6 at.%Yb:YAG, and 1.5 at.%Yb:YAG ceramics were found to be 83.9%, 84.1%, and 83.3%, respectively. Finally, the 940 nm laser diode was used as the pump source to realize the 1030 nm laser output of multistage gradient doping Yb:YAG ceramic slab with a total energy of 3.43 J. The corresponding optical-to-optical conversion and slope efficiencies were 30% and 45%.     

Correlation between local structure variations and critical temperature of (Bi1.6Pb0.4Sr2Ca2Cu3O10+δ)1-x(TiO2)x superconductor

TiO₂ doping content affects the critical temperature (T_c) and the variations of local structure on Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+δ. The (Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+δ)_1-x(TiO₂)_x samples were fabricated with the solid-state reaction process, where x = 0, 0.002, 0.004, 0.006, 0.008, and 0.01. The T_c values of the samples were obtained by measuring resistivity versus temperature, indicating that T_c gradually decreased with increasing doping content (x). To explain the obtained degradation of T_c, carrier properties, role of interlayer coupling, and local structure were systematically investigated using Azlamozov–Larkin theory and its Lawrence–Doniach modification for strong anisotropic superconductors. The calculation of excess conductivity at the mean field region showed that the c-axis coherence length (ξ_c) and the effective inter-layering spacing (d) increased with increasing doping content. X-ray diffraction patterns also showed that the bond distances increased with increasing TiO₂ content. The copper valence (V) and carrier concentration (p) of the samples were determined by analyzing the Cu L_2,3-edge X-ray absorption near edge structure spectra. The values of V and p showed the same trend of decreasing with increasing x. A close correlation between the changes in local structure parameters and degradation of T_c of (Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+δ)_1-x(TiO₂)_x was then probably concluded.     

Hofmeister Series: From Aqueous Solution of Biomolecules to Single Cells and Nanovesicles

Hofmeister effects play a critical role in numerous physicochemical and biological phenomena, including the solubility and/or accumulation of proteins, the activities of enzymes, ion transport in biochannels, the structure of lipid bilayers, and the dynamics of vesicle opening and exocytosis. This minireview focuses on how ionic specificity affects the physicochemical properties of biomolecules to regulate cellular exocytosis, vesicular content, and nanovesicle opening. We summarize recent progress in further understanding Hofmeister effects on biomacromolecules and their applications in biological systems. These important steps have increased our understanding of the Hofmeister effects on cellular exocytosis, vesicular content, and nanovesicle opening. Increasing evidence is firmly establishing that the ions along the Hofmeister series play an important role in living organisms that has often been ignored.