Application of entropy analysis of in situ droplet-size spectra in evaluation of oil chemical dispersion efficacy

In situ droplet-size distributions were measured using a laser in situ scattering and transmissiometry (LISST-100X) particle size analyzer during the evaluation of natural and chemical dispersion efficiency of crude oils under different wave and current conditions. An entropy grouping of the in situ dispersed oil droplet-size spectra has classified the multi-modal droplet-size distributions into different groups based on similar droplet-size spectra characteristics within groups and distinction between groups. A generalized linear logistic regression model was fitted to analyze the effects of a number of factors and their interactions on the grouping of oil droplet-size spectra. The grouped results corresponded to the oil dispersion efficiency at different levels. This new method for droplet-size distribution data analysis can have significant implication in field evaluation of natural and chemical dispersion efficiency of oil.     

Preface to the special issue on seismic array analysis and CEArray

A seismic array is a set of seismographs being arranged in a regular geometric pattern to improve signalto-noise ratio (SNR).Seismic arrays at various length scales have been introduced since early 1960s and have been proved to be superior to single three-component stations for detecting and characterizing signals from earthquakes and explosions.     

雅丹地貌研究评述与展望

雅丹地貌是风蚀地貌研究的重要对象,目前研究较为薄弱.雅丹地貌自瑞典探险家斯文赫定命名并开始研究以来,已有百余年的历史.随着科学技术的不断进步和研究方法的更新,已取得了重要进展,但仍存在许多问题.首先对雅丹地貌的科学定义、空间分布、形态特征、形成发育条件、形成发育过程、形成年代、与环境的关系和分类等8方面的进展和问题进行...     

鱼洞河滑坡地质特征及稳定性分析

在分析滑坡体工程地质条件和滑带土特征的基础上,分析影响因子对滑坡稳定性的敏感性.采用不平衡推力法和简布法,模拟多种外部条件,分析滑坡稳定性表明,滑坡整体处于稳定状态,局部可能失稳,对大坝安全运行不造成巨大危害.     

墙角型陡坡带岩性圈闭油气成藏条件研究——以渤海湾盆地石南陡坡带中段BZ3区古近系东营组为例

BZ3区西部陡坡带位于渤海湾盆地渤中凹陷石南陡坡带中段,构造上处于石臼坨凸起与凸起倾没端相交的夹角地带,石南一号断裂和石南二号断裂在此处相交,形成由多个复杂断阶所组成的复式墙角型陡坡坡折带.通过高精度层序地层学研究认为,BZ3区东营组东二下亚段发育3个4～5级基准面旋回,每个基准面旋回的上升半旋回的下部和下降半旋回均控...     

Characteristics of wind-blown sand and dynamic environment in the section of Wudaoliang-Tuotuo River along the Qinghai-Tibet Railway

Based on the detailed wind data and in situ observation of wind-blown sand in the section of Wudaoliang-Tuotuo River along the Qinghai-Tibet Railway, the dynamic environment of sand flow, involving sand-laden wind, drift potential, sand transport and their time variation were investigated. The prevailing direction of sand-laden wind obviously varies seasonally. Sand-laden wind presents unidirectional characteristics from winter to the next spring and its prevailing direction is westerly. In summer, northeasterly wind begins to increase and lasts for a short period. The annual drift potential along the Qinghai-Tibet Railway reaches 970.54 Vector Units (VU), which belongs to a high-energy wind environment. Directional variability of wind regime (RDP/DP, RDP is the resultant drift potential (RDP) and DP is drift potential) is 0.88. The RDP is 854.31VU in the direction of 89.7°, which indicates that westerly sand-laden wind prevails in this region. Sand transport is well correlated to the frequency of sand-laden wind and increases with drift potential logarithmically.     

Analytic solution of long wave propagation over a submerged hump

A new analytical solution of the long wave refraction by a submerged circular hump is presented. The geometry of the hump is assumed to be axisymmetric and be described by a power function in the radial direction with arbitrary values of both the exponent and the scaling factor. The submergence of the hump is also variable. The water surface elevation governed by the long wave version of the mild slope wave equation is solved by separation of variables, and a series solution of the Frobenius type is obtained. The solution is shown to be valid when the hump is sufficiently submerged or is of a relatively small height. Matching method is employed to illustrate the refraction of long waves under given conditions of incidence. Effects of the shape, the scale, and the submergence of the hump on wave refraction are discussed.     

四川冕宁稀土矿床脉石矿物的微量及稀土元素地球化学特征

包裹体地球化学研究表明，四川冕宁稀土矿床中存在着岩浆成因的萤石、重晶石和方解石，它们的微量元素地球化学特征与热液成因对应矿物有明显差别：岩浆成因重晶石相对富集亲石元素，贫亲硫元素；无论是岩浆成因重晶石，还是萤石均明显富集挥发分。稀土元素地球化学研究显示，不同成因萤石、重晶石在稀土元素总量、ＬＲＥＥ／ＨＲＥＥ、（Ｌａ／Ｙｂ）Ｎ、δＥｕ及δＣｅ等一系列稀土元素地球化学参数上都存在明显的差异。该项研究还揭示了岩浆成因萤石、重晶石是在相对还原和酸性体系内结晶而成的。     

REMOTE SENSING OF ATMOSPHERIC CONSTITUENTS AND THE MULTI-FUNCTION SPECTROPHOTOMETER

A multi-functional solar and skylight spectrophotometer has been developed for the study of atmosphericconstituents and aerosols. The instrument and its performance are described. Due to telescope structure andlock-in amplification technique adopted,the sensitivity of the instrument is high enough to conduct direct sunmoon and twilight measurement for several atmospheric species and the degree of polarization and intensityobservation for sky light. From measured results, the total column abundance of atmospheric species and theoptical characteristics of aerosol can be retrieved. In this paper, the daily averaged column abundance of O_3measured in Beijing by direct sun was compared with Dobson spectrophotometer nearby. The two did notshow significant difference.     

江汉-洞庭盆地构造特征和地震活动的初步分析

本文根据地质、地球物理和地震等资料,初步分析了江汉-洞庭盆地构造及其演化和地震活动的基本特征。此盆地由江汉坳陷、华容隆起和洞庭湖坳陷组成,整个盆地呈现二坳一隆、多凹多凸的构造特征。盆地之下是低缓的北东向莫霍面隆起带,埋深30—31km。自早白垩世至第四纪盆地经历了裂陷、强烈裂陷和区域性沉降等复杂过程,第四纪仍存在一定程度的断裂活动和断块差异活动。盆地区有中强地震和小震活动,地震带基本位于第四纪差异活动较明显的地区和莫霍面隆起的斜坡带