水浴法对工业级氢氧化镁的改性研究

水浴加热条件下,表面活性剂SDS、SLS和PEG10000的复配体改性工业级Mg(OH)2,得到了中位径(D50)1.55μm、分散性好的改性Mg(OH)2。水浴法改性Mg(OH)2的工艺条件为氢氧化镁浓度1.50 mol/L、表面活性剂用量2.50%、矿化剂氯化镁用量3.50%、水浴温度80℃、水浴时间6.0 h、搅拌速度850 r/min。     

改性石英填料的性能及评价方法

本文主要介绍改性石英填料的粘度、浸润性能（渗透时间、浸润角、浸润点等）等指标，以及表面改性效果的评价方法。     

Surface Trace Gases at a Rural Site between the Megacities of Beijing and Tianjin

The North China Plain （NCP） has recently faced serious air quality problems as a result of enhanced gas pollutant emissions due to the process of urbanization and rapid economic growth. To explore regional air pollu- tion in the NCP, measurements of surface ozone （O3）, nitrogen oxides （NOx）, and sulfur dioxide （SO2） were car- ried out from May to November 2013 at a rural site （Xianghe） between the twin megacities of Beijing and Tianjin. The highest hourly ozone average was close to 240 ppbv in May, followed by around 160 ppbv in June and July. High ozone episodes were more notable than in 2005 and were mainly associated with air parcels from the city cluster in the hinterland of the polluted NCP to the southwest of the site. For NOx, an important ozone precur- sor, the concentrations ranged from several ppbv to nearly 180 ppbv in the summer and over 400 ppbv in the fall. The occurrence of high NOx concentrations under calm condi- tions indicated that local emissions were dominant in Xianghe. The double-peak diurnal pattern found in NOx concentrations and NO/NOx ratios was probably shaped by local emissions, photochemical removal, and dilution re- sulting from diurnal variations of surface wind speed and the boundary layer height. A pronounced SO2 daytime peak was noted and attributed to downward mixing from an SO2-rich layer above, while the SO2-polluted air mass transported from possible emission sources, which differed between the non-heating （September and October） and heating （November） periods, was thought to be responsible for night-time high concentrations.     

有机硅涂层表面能对海生物附着的影响

随着海洋生态环境保护和防止海洋生物污损的要求,人们试图用具有特殊表面性能的涂层取代有毒涂层来减弱或消除海生物的附着。本文通过对含有机硅防污涂层表面能的测量计算,探讨了涂层表面能各分量对附着生物的影响。实验结果表明,在表面能低色散分量的含有机硅涂层上,随涂层与水的相互作用力分量减小,绿藻和玻璃海鞘的污损增加。     

影响黄土湿陷性因素的微观试验研究

借助扫描电子显微镜和光学数码显微镜, 分析了不同含水率黄土试样表面微区结构变化与黄土湿陷性的关系和不同埋深土样在水与外力共同作用下湿陷前后微观结构的变化特征。利用图像处理软件对所获取的微结构图像进行研究, 分析了黄土湿陷前后土样中大、中、小孔隙和微孔隙数量的变化。结果表明:湿陷后比湿陷前土样微孔隙增多31.18%, 小孔隙增多54.07%, 中孔隙减少30.49%, 大孔隙减少90.14%。这说明随着压力的不断增大, 黄土中的孔隙被逐渐压缩, 大孔隙和中孔隙的数量逐渐减少, 小孔隙和微孔隙的数量逐渐增加, 为黄土的湿陷变形提供了充分的空间。讨论了土样中4类孔隙对黄土湿陷的贡献量, 从微观角度综合分析了黄土湿陷的成因机理。     

Interaction of Waves, Surface Currents, and Turbulence： the Application of Surface-Following Coordinate Systems

Surface waves comprise an important aspect of the interaction between the atmosphere and the ocean, so a dynamically consistent framework for modelling atmosphere-ocean interaction must take account of surface waves, either implicitly or explicitly. In order to calculate the effect of wind forcing on waves and currents, and vice versa, it is necessary to employ a consistent formula- tion of the energy and momentum balance within the airflow, wave field, and water column. It is very advantageous to apply sur- face-following coordinate systems, whereby the steep gradients in mean flow properties near the air-water interface in the cross-interface direction may be resolved over distances which are much smaller than the height of the waves themselves. We may account for the waves explicitly by employing a numerical spectral wave model, and applying a suitable theory of wave–mean flow interaction. If the mean flow is small compared with the wave phase speed, perturbation expansions of the hydrodynamic equations in a Lagrangian or generalized Lagrangian mean framework are useful: for stronger flows, such as for wind blowing over waves, the presence of critical levels where the mean flow velocity is equal to the wave phase speed necessitates the application of more general types of surface-following coordinate system. The interaction of the flow of air and water and associated differences in temperature and the concentration of various substances (such as gas species) gives rise to a complex boundary-layer structure at a wide range of vertical scales, from the sub-millimetre scales of gaseous diffusion, to several tens of metres for the turbulent Ekman layer. The bal- ance of momentum, heat, and mass is also affected significantly by breaking waves, which act to increase the effective area of the surface for mass transfer, and increase turbulent diffusive fluxes via the conversion of wave energy to turbulent kinetic energy.     

基于微结构参数主成分的黄土湿陷性评价

黄土的湿陷性与其微观结构特征密切相关,它的微结构又受其应力状态和所处的含水状态影响。通过改变含水率与固结压力,对西安原状黄土进行了湿陷性试验,由此分析了不同含水率与固结压力条件下湿陷性的差异与联系,同时通过电镜扫描（SEM）获取了湿陷前、后黄土试样的微结构照片,进而获取了相应条件下的SEM照片的简单微结构参数。分析了湿陷前、后微结构参数的变化,探讨了简单微结构参数间相关关系,基于主成分分析法构建了合成微结构参数。研究表明：随着固结压力的增大,颗粒体所占比重越来越大,第1主成分近似线性增大,黄土湿陷系数与其累积主成分呈线性关系。根据这一重要认识,建立了主成分得分的湿陷系数计算方法,进而建立了黄土湿陷性评价方法。该研究对定量研究黄土湿陷性的微结构效应做了有益的探索。     

低渗透储层微流动机理及应用进展综述

低渗透储层具有孔喉细小、孔隙结构复杂、比表面积大,黏土矿物类型丰富等特点,这些特点致使流体在低渗透储层中流动会产生强烈的微流动效应。微流动效应主要包括稀薄效应和不连续效应、表面优势效应、低雷诺数多流态效应、多尺度多相态效应等,这些特殊效应将影响描述流体流动的微分方程及边界状态。孔隙结构特征、黏土矿物产状、润湿性、岩石矿物荷电性等是低渗透储层微流动的影响因素,通过控制这些因素,可以改变流体在低渗透储层中的流动特征,从而控制油、气、水产量。目前已经形成了界面修饰技术、电化学驱油等采油新技术。以微流动机理为基础,结合孔隙结构特征,找出影响低渗透储层流体流动的主控因素,采用具有针对性的开采技术将成为高效开发低渗透油气资源的有效途径。     

任意方向震源二维兰姆问题的一个精确解

均匀弹性半空间表面或内部震源产生的地震波场的解析解属于Lamb问题,采用Cagniard-deHoop方法,对与水平面呈任意夹角的表面线源,求解了其作用于弹性半空间时的拉普拉斯-傅里叶双积分变换解.以δ-脉冲函数为例,给出了任意方向作用力下波场的构成,并定量解出了P波、S波、首波和Rayleigh波等各波的位移表达式,分析了不同作用方向下各波位移的相对大小.建立数值模型并进行数值模拟,模拟结果验证了理论研究的正确性.研究成果为近地表地震波场的研究提供了理论依据.     

利用漂流浮标资料对黑潮及其邻近海域表层流场及其季节分布特征的分析研究

利用1987年以来WOCE项目及我国自行投放或进入黑潮及其邻近海域(15°~36°N,114°~135°E)的共计323个卫星跟踪海表面漂流浮标资料,得到全年平均及季节平均的浮标轨迹及(1/4)°×(1/4)°格点平均的表层流矢量结果。分析认为:对于全年平均的表层流场,黑潮表层流路主要表现了对大洋西边界地形的适应,并呈现出6个较大的弯曲,其中在反气旋型弯曲处都发生分支或入侵现象、气旋型弯曲处这种现象却不明显。对于季节平均的表层流场,黑潮表层不同流段分别表现出各自显著的季节差异:吕宋海峡附近海域,表层水向南海的入侵只发生在秋、冬两季,而春、夏两季却不发生;在台湾以东海域,黑潮表层流路与黑潮右侧反气旋涡的存在与否密切相关,春季没有涡旋存在时,黑潮表层流路常出现气旋式大弯曲,其他三个季节反气旋涡存在时,黑潮表层流路相对平直;在台湾东北海域,黑潮表层水向东海南部陆架区的入侵以秋、冬季最强,春季次之,而夏季几乎不发生;在赤尾屿以北的东海黑潮中段,黑潮流动比较稳定,其表层平均流径走向由偏北到偏东依次约为冬(北偏东30°)、春(北偏东33°)、秋(北偏东38°)、夏(北偏东45°);流路宽度由宽至窄依次约为秋(90 km)、春(80 km)、冬(70 km)、夏(60 km),而流速由大至小依次为夏、春、秋、冬,且各季节都表现出北段流速大于南段的现象;在九州西南海域,春、秋两季黑潮表层水发生明显的向北入侵,入侵的黑潮水与东海外陆架水共同成为对马暖流的一部分来源,而夏季这种现象不明显,九州西南海域黑潮表层流路北界的位置以秋季最为偏北(但最北不超过31°N)、流路也最宽;在琉球群岛外缘海域,南半部基本没有北上的表层流存在,只有在冲绳群岛-奄美群岛以东海区,秋、夏、春三季表层反气旋涡旋都比较活跃,在涡旋的西侧有顺着冲绳群岛-奄美群岛的东北向流,其中秋季最为明显。这些结果可以为黑潮及其邻近海域的深入研究提供较为客观、直接的参考。