东海南部黑潮区春季温盐度垂直分布类型及其逆现象成因的初步分析

用１９８８～１９９６年在东海南部黑潮区共５个航次的春季水文观测资料,分析了该海区温、盐度垂直分布类型的地理分布,讨论了春季温、盐度逆转现象的形成原因。这主要是春季季风已转变为南风,在南风的驱动下,迫使表层水离岸向东向外海扩张,台湾暖流向北伸展,黑潮次表层水的向岸入侵的结果     

建立天空场景的模拟算法

建立真实感的天空场景,在环境仿真和气象现象模拟中,有着极其重要的应用价值,也是计算机可视化研究中的难题。首先通过确定色彩层次模型,改进基于中点的变位方法生成基本云图,然后使用基于图像的方法进行云图映射,最后融合气象信息要素等过程生成天空背景,并采用光照叠加、背景合成及色彩调整等方法,产生千姿百态、形象逼真的天空场景图。可在多种气象现象的模拟仿真,纹理贴图的产生以及气象信息可视化系统的开发等方面发挥重要的作用。     

Revisiting the existence of an effective stress for wet granular soils with micromechanics

A possible effective stress variable for wet granular materials is numerically investigated based on an adapted discrete element method (DEM) model for an ideal three‐phase system. The DEM simulations consider granular materials made of nearly monodisperse spherical particles, in the pendular regime with the pore fluid mixture consisting of distinct water menisci bridging particle pairs. The contact force‐related stress contribution to the total stresses is isolated and tested as the effective stress candidate for dense or loose systems. It is first recalled that this contact stress tensor is indeed an adequate effective stress that describes stress limit states of wet samples with the same Mohr‐Coulomb criterion associated with their dry counterparts. As for constitutive relationships, it is demonstrated that the contact stress tensor used in conjunction with dry constitutive relations does describe the strains of wet samples during an initial strain regime but not beyond. Outside this so‐called quasi‐static strain regime, whose extent is much greater for dense than loose materials, dramatic changes in the contact network prevent macroscale contact stress‐strain relationships to apply in the same manner to dry and unsaturated conditions. The presented numerical results also reveal unexpected constitutive bifurcations for the loose material, related to stick‐slip macrobehavior.     

新疆库米什盆地硝酸盐类矿床成矿离子迁移规律及成矿模型

为了深入认识库米什盆地硝酸盐矿床成矿离子的空间分布特征、表层沉积物中硝酸盐含量较高的原因,以盆地硝酸盐矿床为研究对象,开展研究区内各类补给水样和沉积物样可溶性盐类物质化学组成的定量分析研究;结合野外地质踏勘工作,探讨研究区硝酸盐矿床成矿离子的迁移规律,初步建立盆地硝酸盐矿床沉积成矿作用模型.结果表明,K+、Na+、NO...     

降雨形式对毛细阻滞覆盖层防渗性能的影响研究

毛细阻滞覆盖层的防渗性能对于控制渗滤液和减轻垃圾填埋场周边环境的污染具有重要意义,因此得到广泛研究。前人在研究中多采用恒定降雨强度来模拟降雨气象条件,而对降雨形式对毛细阻滞覆盖层防渗性能的影响关注较少。因此,采用自主研发的土柱降雨入渗试验系统,分别对短时强降雨和长时弱降雨两种降雨情况下,降雨形式对毛细阻滞覆盖层防渗性能的影响开展了研究,并揭示了最不利降雨形式。同时,采用SEEP/W软件对各试验工况进行数值模拟,以使模拟结果与试验结果能够相互印证。研究结果表明：试验结果与模拟结果基本一致,最大误差不大于3%;在短时强降雨情况下,降雨形式仅对覆盖层上部的体积含水率和孔隙水压力有较大影响;而在长时弱降雨条件下,降雨形式对整个覆盖层的体积含水率和孔隙水压力均有显著影响;降雨形式对覆盖层突破时间及渗漏量均有影响,前锋型降雨的突破时间最短,产生的渗漏量最大,后锋型降雨的突破时间最长,产生的渗漏量最小;前锋型降雨更易造成覆盖层突破失效而产生较大的渗漏量,为最不利降雨形式。该研究结果可为毛细阻滞覆盖层设计提供参考依据。     

Comprehensive tests on rising height of capillary water for coarse grained soil

According to the comprehensive tests on the rising height of capillary water for seven kinds of different coarse grained soil by use of the method of standpipe,the relationship between the rising height of capillary water and time was obtained,and the influencing factors and rules were analyzed.The data of the steady rising height of capillary water were obtained,and the regression equation of coarse grained soil on steady height and physical indexes(effective grain d 10 and porosity n) was found.Compared with Hazen’s and other expressions that could estimate the steady height of capillary water of coarse grained soil,the proposed method is satisfactory and the defects of the latter were pointed out.     

岷县漳县6.6级地震后申都乡地窖宏观异常现象及其机理探讨

2013年7月22日甘肃岷县漳县M_s6.6地震后岷县申都乡某地窖出现冒白色烟雾的宏观异常现象。本文通过土壤气Rn、Hg现场检测和采样后气相色谱检测、生物显微镜观察结果,探讨了气体来源、赋存和运移机理以及异常形成的物理化学机制。认为该点具有灵敏的断层活动响应,可作为今后开展断层活动及未来甘东南地震趋势预测判定的断层土壤气监测点进行长期监测。     

从断裂强度到临界点──重整化群理论在地震预报中的应用述评

介绍了临界自组织现象和重整化群方法的基本原理，对地震的自组织临界行为作了较为深入的讨论，并就这一领域中的一些概念和观点发表了作者自己的见解。     

On estimating the hydraulic properties of soil,Part 2. A new empirical equation for estimating hydraulic conductivity for sands

A new empirical equation to estimate hydraulic conductivity is proposed, based on a large set of measured data for hydraulic properties of soil. The equation is simpler and more accurate than the series-parallel model. Under conditions of insufficient data, the new equation provides a good estimation of hydraulic conductivity for sands. For the same class of soils, another empirical equation is proposed to estimate the power N in the Averjanov-Irmay function.