羟基对界面水分子的扰动与其对非离子型氢氟烃杂化表面活性剂聚集行为的改变

本文合成并比较了具有和不具有羟基的两种非离子型氢氟烃杂化表面活性剂,它们均表现出良好的热稳定性和优异的表面活性. 实验观察到羟基对改变其溶液的表面张力和所形成胶束的形态具有较大的影响. 该作用可归因于烷烃基团从空气/水表面上方到其下方的重排以及由羟基诱导的界面水结构的扰动. 本工作提供了一种通过修改界面处的取向结构来弱化碳氢链和碳氟链之间的不混溶性,从而利于设计具有不同界面性质表面活性剂的策略.     

近红外光谱法检测聚醚多元醇伯羟基与仲羟基的相对含量

文章利用近红外光谱法,采用多元线性回归检测了聚醚多元醇的伯羟基与仲羟基的相对含量,得到了较好的预测结果,对工业在线检测具有重要的参考价值。     

EPR of Charge Carriers Stabilized at the Surface of Metal Oxides

Some cases of formation and stabilization of charge carriers (electron and holes) at the surface of solid oxides are discussed. Charge carriers can be simultaneously or independently stabilized at the surface metal oxides. In the former case, they usually derive from a process of charge separation in the solid triggered by above band gap irradiation. In the second case, the charge carrier isolation is the result of a chemical alteration of the stoichiometric equilibrium of the solid either by matter addition or by effect of chemical impurities (valence induction). Electron paramagnetic resonance (EPR) is highly suited to monitor the process of charge separation and to characterize electron or hole centers stabilized in the solid or at its surface. In this paper examples of trapped electron and/or trapped hole centers as detected by continuous-wave EPR at the surface of simple binary oxides are discussed with particular emphasis to the formation mechanism, the EPR parameters and the chemical reactivity.     

AFM Observation of a Mica Surface Treated with Silane Coupling Agent Having a Mercapto Group

The topography of mica surface after treatment with silane coupling agent having a mercapto group was studied using an atomic force microscope. The cleaved mica plate was used as a model inorganic surface. The effect of treatment condition on the topography of the mica surface was investigated. Agglomerates consisting of self-condensed silane molecules were observed on the surface. However, their amount and size were smaller than those for silanes having other organo-functional groups such as amino, methacryloxy and vinyl groups. Aqueous and water/2-propanol mixture solutions gave a smoother surface as compared with a 2-propanol solution. There was no significant influence discernable from di- and trialkoxy structures. The aqueous solution of silane coupling agent having a mercapto group showed an acidic pH. This was the reason why the smoother silane-treated layer was formed by the silane with the mercapto group than by those with other organic functional groups, because the silanol group generated by hydrolysis is stable in an acidic pH.     

多价态高分子链在受体平面上的超选择性吸附

利用三维朗之万动力学模拟研究了多价态高分子链在受体平面上的吸附行为。其在受体平面上的吸附具有超选择性,随着高分子链上配体浓度的增大,发生超选择性吸附时的平面受体浓度范围变窄;而超选择性吸附最显著时的平面受体浓度,即最佳平面受体浓度随着链上配体浓度的增大而减小。对处于吸附态的多价态高分子链的构象性质进行了系统地研究,发现链的平衡回转半径R_g及其水平分量R_g},随着平面受体浓度的增大都存在极大值。其平衡回转半径R_g与其链长N间的标度指数表明当平面受体浓度的增大时,处于吸附态的链构象介于二维链构象和三维链构象之间;随着平面受体浓度的进一步增大,吸附在平面上的多价态高分子链发生轻微的塌缩     

硅藻土表面羟基的漫反射红外光谱(DRIFT)研究

运用傅里叶变换漫反射红外光谱（DRIFT）及氘化技术,研究了硅藻土的表面羟基结构及其在热处理中的变化。     

内陆河道表层水体反射光谱的走航观测研究

现场水体光谱观测是水体光学性质、水色遥感反演建模等研究不可或缺的基础性工作之一.常规的倾斜观测方法受其较为严格的观测几何条件限制,需要依据船体位置、太阳方位等不断调整观测角度,特别是针对河道水体光谱观测时,还须考虑河道走向、岸线遮蔽物等情况,因此,只能设置若干站点进行离散样点的观测,难以在岸线环境较为复杂的河道水体开展...     

水催化脱卤反应:构建每次一个水分子的纳米化学反应体系(英文)

pacc:8240,8760E Acombinedexperimentalandtheoretical studyofthephotochemistryofCHBr3inpurewa terandinacetonitrile/watermixedsolventsisre portedthatelucidatesthereactionsandmecha nismsresponsibleforthephotochemicalconver sionofthehalogenatomsinCHBr3intothre…     

Understanding Symmetric and Asymmetric DNA Patterns by Water Flow on a Solid Surface

In order to use DNA for making molecular device, specific DNA patterns on a solid surface should be constructed. In this paper, we will show that the random interactions between the DNA segments and the solid surface play an important role in the final symmetric and asymmetric DNA patterns obtained by water flow.     

Steric Effect of an ortho-Alkyl Group on the Stretching Vibration Frequency of Phenol Hydroxyl

It is shown that the derivatives of mono-ortho-alkylsubstituted phenols, which in the ortho-position have primary and secondary alkyl groups, and also tertiary alkyl groups have different correlations between the frequencies of the stretching vibration of the OH bond and Pal'm's steric constants E _s ⁰.     

Experimental Simulation of the Generation of a Vortex Flow on a Water Surface by a Wave Cascade

The generation of a vortex flow by waves on a water surface, which simulate an energy cascade in a system of gravity waves at frequencies of 3, 4, 5, and 6 Hz, has been studied experimentally. It has been found that pumping is accompanied by the propagation of waves on the surface at different angles to the fundamental mode and by a nonlinear interaction between waves resulting in the generation of new harmonics. It has been shown that large-scale flows are formed by modes of the lowest frequency of 3 Hz intersecting at acute angles. The energy distribution of the vortex motion can be described by a power-law function of the wavenumber and is independent of the energy distribution in a system of surface waves. The energy coming to large-scale vortex flows directly from the wave system is transferred to small scales. A direct rather than inverse energy flux is established in the system of vortices.     

表面羟基辅助甲醛分子在金红石型TiO2(110)表面迁移动力学研究

As the photo-dissociation product of methanol on the TiO₂(110) surface,the diffusion and desorption processes of formaldehyde (HCHO) were investigated by using scanning tunneling microscope (STM) and density functional theory (DFT).The molecular-level images revealed the HCHO molecules could diffuse and desorb on the surface at 80 K under UV laser irradiation.The diffusion was found to be mediated by hydrogen adatoms nearby,which were produced from photodissociation of methanol.Diffusion of HCHO was significantly decreased when there was only one H adatom near the HCHO molecule.Furthermore,single HCHO molecule adsorbed on the bare TiO₂(110) surface was quite stable,little photo-desorption was observed during laser irradiation.The mechanism of hydroxyl groups assisted diffusion of formaldehyde was also investigated using theoretical calculations.     

圆柱体出水运动的自由面效应及水冢现象分析

以圆柱体为例,研究自由面附近刚性物体的受力状态,分析垂直运动圆柱体出水时的自由面效应以及水冢现象.建立基于势流理论考虑自由面效应的数学模型,并用边界元方法求解该模型.求解过程中考虑非线性自由面运动学以及动力学边界条件.通过求解控制方程以及边界条件,模拟恒速刚性圆柱体出水时的水冢现象及其穿越水冢过程.通过数值解和实验值的比较验证方法的可靠性.分析结构出水时的压力变化、自由液面变形、圆柱体所受的垂向合外力以及流场速度矢量的变化,并展开讨论.结果表明:考虑自由面效应的非线性方法能够更准确地预报自由面附近刚性运动物体的受力特性.     

傅里叶红外光谱仪测定地表水中的石油类

傅里叶红外光谱仪测定地表水中石油类,用一次定量萃取代替两次萃取定容,用无水硫酸钠过滤吸水代替经过硅酸镁柱.方法的精密度和准确度均达到国家标准要求,减轻了工作量,提高了分析速度,可用于日常样品地表水中石油类的监测.     

表面等离子体共振技术研究肝素对高迁移率族蛋白1与晚期糖基化终产物受体亲合力的影响

测定肝素与高迁移率族蛋1(HMGB1),及其与晚期糖基化终产物受体(RAGE)的亲和力,探讨肝素对HMGB1/RAGE亲和力的影响.用表面等离子体共振技术,实时分析肝素与HMGB1,HMGB1与RAGE的亲和常数,利用其binding analysis分析肝素对HMGB1/RAGE配受体结合的影响.肝素与HMGB1的动力学速率常数ka=1.78×105 L·(mol·s)-1,kd=8.02×10-4·s-1,亲和常数KA=2.22×108L·mol-1,KD=4.5×10-9 mol·L-1;HMGB1与RAGE的动力学常数ka=1.85×103L·(mol·s)-1,kd=1.81×10-4·s-1,亲和常数KA=1.02×107L·mol-1,KD=9.77×10-8mol·L-1.肝素与RAGE的亲和力极低.当浓度分别为50,100,1 000,10 000 U·L-1的肝素与HMGBl混合后,后者与RAGE的亲和力下降.上述不同浓度的肝素对HMGB1/RAGE亲和力的影响没有显著差异.结果表明,肝素可与HMGB1结合并影响后者与RAGE的亲和力,该作用并不与肝素浓度呈正相关.     

球端面梯折透镜最佳耦合条件的探讨

本文就利用球端面梯折（梯度折射率）透镜进行半导体激光器和光纤耦合问题进行了探讨，给出了最佳耦合的条件。     

ICP-AES测定地表水中总砷

用ICP—AES测定地表水中总砷，检出限为：2．97μg/L，回收率在95％-105％之间，相对标准偏差为1.13％-2．24％，结果令人满意。     

气相色谱法测定地表水中的内吸磷

实验建立了气相色谱法测定地表水中内吸磷的方法.两种内吸磷化合物能有效分离,且方法线性均良好,当取样量为250mL时,两种内吸磷的方法检出限均为0.3μg/L,在两个不同加标水平下,实际地表水样品中两种内吸磷的平均加标回收率为98.3％-107.4％,相对标准偏差为2.1％-3.9％.本方法可准确测定地表水样品中的内吸磷.     

Doppler Spectra of Centimeter and Millimeter Microwaves Backscattered from a Rough Water Surface at low Grazing Angles

We present the results of processing of X- and Ka-band radar signals backscattered from a rough water surface at low grazing angles. Processing is made by the method of decomposing a Doppler spectrum into three basic line profiles. Each of these profiles corresponds to a certain scattering mechanism. Comparative evaluations of the contribution of the Bragg mechanism described by the Gaussian line profile and two non-Bragg mechanisms described by the Lorentz and Voigt profiles are obtained.