深水Stokes漂流公式的一种新形式

本文在未将Stokes波的势函数参数β的前提下使用近似解迭代方法重新推导了Stokes波的水质点的轨迹方程。在具体推导中发现水平位移与垂向位移在作近似解迭代时，收敛于精确解的速度是不相同的，垂向位移在一次迭代后即与精确解非常近似，而对于水平位移必须做二次迭代才能达到较好的精度。由二次迭代的水平位移方程即可获得Stokes漂流公式的一种新式，该形式表明，在三阶精度下Stokes漂流与所在深度的水质点的振幅A的平方成正比。运用由垂向位移方程解得的振幅与参数β的关系式可证明经典Stokes漂流公式可以看作是新漂流公式在特定坐标系下的特定垂直断面处的结果。     

大尺度海温异常对热带大气Kelvin波的影响

本文用一个简单的斜压两层模式，在热力学方程中只考虑牛顿冷却和感热加热，从理论上分析了大尺度海温异常时感热加热带大气压Ｋｅｌｖｉｎ波的影响。研究发现，牛顿冷却使大气Ｋｅｌｖｉｎ波振幅减，并使波速减慢；感热加热可使得Ｋｅｖｉｎ波波速加快；当海气温差超过某一临界值时，波动趋于不稳定。     

Adsorption of uranyl complex ions on hydrous titanium oxide (HTO)——Ⅱ. Infrared spectrum investigation

-The i. r. spectra of Na4 [UO2 (CO3)3], Na [UO2 (OH)3] and the surface species of uranium on HTO underthe condition of flowing natural seawater and concentrated seawater (NaCl-NaHCO3-U) were recorded, with the bands of urany! of surface species obtained and the finding that iigands of surface species besides HTO are mainly water and OH, and there are some CO32- groups under the condition of natural seawater. Some relations between the complex properties and the j. r. spectroscopic characters for uranyl complexes were studied, and the transferred change quantity of surface complex was calculated.Structure models for surface species of adsorption are herein presented and the mechanism for uranium adsorption is deduced.     

河口环流和盐水入侵I--模式及控制数值试验

本文应用ECOM模式,设计1个控制试验,研究理想河口环流和盐水入侵的动力过程.数值计算结果表明,盐水入侵产生盐度锋面,在锋面处底层存在着向陆的密度流,为保持断面上质量连续,上层的流速趋于增大;近口门附近底层流有偏南分量,表明有横向环流存在.在口门外因斜压和底形的作用,产生明显的上升流.盐水入侵在空间上具有不对称性,高盐水位于北岸的下层.在拦门沙上游出现上下2个相反方向的横向环流,而在口门处只出现1个顺时针方向的横向环流.从动力机制上分析了盐水入侵的空间不对称性和横向环流的产生.     

太阳spike辐射中的MHD振荡

我们在1981年5月16日所观测到的典型的微波大爆发的spike辐射中,发现存有～1.4—1.6秒的准周期振荡特征。本文依据MHD波理论,对观测进行了分析讨论,本文认为在日冕圈内外传播着的快磁声波(“腊肠”模)调制了源区的磁场以及电子束的投射角分布,从而影响了ECM不稳定性的增长率,因此而产生了spike辐射中的准周期振荡。另外,本文还对一些有关的物理参数作了定量的估算。     

水库滑坡成因机制研究进展与展望

滑坡是水库库区主要地质灾害类型之一,开展水库滑坡成因机制研究具有重要理论意义和工程应用价值.利用WebofScience(WoS)数据库和VOSviewer文献计量工具对1999-2018年已发表的969篇以水库滑坡为主题的相关论文进行研究趋势分析.文献计量分析表明三峡库区滑坡稳定性和变形研究是未来水库滑坡成因机制研究主要趋势.从库水对滑坡的宏观力学作用方式、库水作用下岩土体渗流应力耦合机理和库水对岩土体劣化作用过程等方面,对国内外水库滑坡成因机制研究的主要成果与进展进行了综述.综合现有的研究成果指出水库滑坡在精细化地质建模、岩土体多场耦合特征参数获取和岸坡长期演化评价等方面尚存在不足.基于上述问题,提出水库滑坡成因机制研究应以多场信息监测为重要手段,立足多学科交叉,采用大数据融合与挖掘和人工智能技术等解决水库滑坡长期演化趋势难题.考虑水库滑坡所处地质环境的复杂性,建议未来应在水库滑坡立体精细地质建模、多场关联监测、地质结构多场多尺度演变过程、基于监测数据大数据分析的滑坡预警阈值确定和原位试验综合平台构建等方面进一步深入研究.     

Linking a prolonged Neo‐Tethyan magmatic arc in South Asia: Zircon U‐Pb and Hf isotopic constraints from the Lohit Batholith,NE India

The Neo‐Tethyan subduction that operated before the India‐Asia collision resulted in an Andean‐type convergent margin in South Asia and was associated with extensive arc magmatism that formed the Transhimalayan batholiths. Magmatism in the Gangdese Batholith, the largest batholith exposed in the Lhasa terrane of southern Tibet, is considered to have lasted from the early Jurassic to Eocene. However, eastward correlation of the Gangdese Batholith is uncertain because it is truncated by the eastern Himalayan syntaxis. Here, we report new data from the Lohit Batholith, NE India, including: (i) zircon U‐Pb ages of five granitoids from ca. 148 to 96 Ma; and (ii) zircon Hf isotopes of these rocks that yield high and positive ε_Hf(T) values. We argue that the Lohit Batholith is the eastward extension of the Gangdese Batholith, and can be correlated southward to the Wuntho‐Popa arc in West Burma, thus linking a prolonged Neo‐Tethyan magmatic arc system from southern Tibet to Southeast Asia.     

Numerical modeling of the elastoplastic damage behavior of dry and saturated concrete targets subjected to rigid projectile penetration

The objective of the present paper is to present a numerical study on the penetration performance of concrete targets with 2 different water contents. Numerical analysis has been performed by using the finite element code Abaqus/Explicit, in which a coupled elastoplastic damage model has been developed for saturated/unsaturated concrete under a wide range of confining pressures. The performance of proposed model has been firstly verified by simulating the triaxial compression tests and penetration tests realized with saturated/dry concretes. Comparisons of available experimental results and numerical simulations show that the proposed model is able to reproduce satisfactorily the mechanical behavior of saturated and dry concretes. A higher failure stress and a more important pores closing are generally obtained in dry concrete samples with respect to saturated ones. Furthermore, the main observed patterns of penetration test realized with saturated concrete targets are also satisfactorily simulated by the numerical results. Therefore, the proposed model is used to numerically predict the penetration performance of dry concrete target, and the penetration performance of dry/saturated concrete target is discussed. We observe that in dry concrete target, the penetration of projectile is strongly declined, and a smaller damage zone is created. The numerical predictions and discussions can help engineers to enhance their understandings on the influence of hydraulic conditions on structural vulnerability of concrete structures subjected to near‐field detonations or impacts.     

Excel在形变观测数据处理中的应用

利用Excel的数据处理功能以及自带的"Visual Basic "语言进行二次开发,然后以宏的形式连接在Excel界面上,实现了形变观测数据的处理.