近海核电厂核素地下水释放通量的模型计算方法

为了定量计算陵区近海核电站排水管线泄漏情景下核素通过地下水途径向海洋环境的释放通量，以某近海核电站为例进行研究。首先，应用GOCAD软件建立三维地形地质模型，刻画地层的分布、剥蚀以及倾向等特点；然后，运用地下水数值模拟软件FEFLOW精细刻画丘陵区地下水系统的补给、径流和排泄特征；最后，以不被吸附滞留的核素³H和被吸附滞留的核素⁹⁰Sr、¹³⁷Cs为对象，通过实验测定了⁹⁰Sr、¹³⁷Cs在不同岩土介质中的分配系数，模拟计算了排水管线连续渗漏60 a后³H、⁹⁰Sr、¹³⁷Cs在地下水中的放射性分布及释放。结果表明：³H迁移速度基本与地下水流速一致，地下水中的最大放射性浓度为0.285 0 Bq/L，第20 000天时向收纳水域的释放通量达到最大值，约526 Bq/d；⁹⁰Sr吸附性能相对较弱，最大迁移距离约80 m，地下水中的最大放射性浓度为0.032 1 Bq/L；¹³⁷Cs吸附能力较强，相当长的时间内被滞留在管线附近，地下水中最大放射性浓度分别为6.840×10^-3 Bq/L，释放通量为0 Bq/d。由弥散度的不确定分析可知，弥散度越大，地下水中³H的最大放射性浓度越小，向海洋环境的释放通量越多。     

随钻测录井地质导向二维分解实时绘图方法

根据随钻测录井实时地质导向和大斜度、水平井评价成图技术需求，针对传统绘图方法存在的弊端，提出了将测录井信息、井眼轨迹和地质模型进行二维分解的实时绘图方法。针对二维分解绘图方法绘图时空复杂度较高的问题，给出了不同事件驱动下的局部实时计算和拷屏重绘算法，控制了对CPU和内存的消耗、提高了绘图效率，消除了实时绘图的闪烁和卡顿现象。应用实例表明，二维分解实时绘图方法能够实现大尺度随钻测录井地质导向图形的流畅、无卡顿实时绘图，可提高大斜度、水平井储层模型评价的刻画精度和时效。     

雄安新区地热地质模型探究：来自地球物理的证据

雄安新区内地热资源丰富，区内有牛驼镇地热田、容城地热田和高阳地热田，地热资源开发利用较早，但是对其深部热源机制仍未形成统一观点。为了研究雄安新区内地热田深部热源机制，在新区及外围进行了深反射地震和长周期大地电磁探测，对取得的同剖面的深反射地震和大地电磁数据进行处理和综合解释，探明了研究区从地表至莫霍面范围内地质构造和电性结构。下地壳结构在深反射地震剖面与大地电磁剖面上有很好的对应关系。电阻率低值区对应着在深反射地震剖面上存在一系列反射同相轴，且同相轴可以延续到莫霍面，电阻率高值区对应着在深反射地震剖面上无明显连续反射同相轴，尤其是在莫霍面之上呈现地震反射近似"空白区"。结合区域地热资料构建了研究区深部地热地质模型，对新区内深部地热机制进行了解释。该模型为"二元"生热模型，其热源包含两个部分，深部地幔热源和地壳放射性元素衰变生热。放射性元素衰变生热占地表热流的接近30%，而幔源热流在地表热流中的占比可达约70%。在牛驼镇下方，莫霍面以上，由于地幔热物质上涌造成下地壳上隆，幔源岩浆底侵作用于下地壳形成了局部热异常，该热异常具有低速高导的地球物理特征，认为是牛驼镇地热田和容城地热田的深部热源；以区域断裂为热通道，大地热流由深部向上传导、扩散到牛驼镇凸起和容城凸起顶部，对碳酸盐岩储水层进行加热，形成地热储层；上覆新近系沉积地层是良好的热盖层。     

30 m global impervious surface area dynamics and urban expansion pattern observed by Landsat satellites: From 1972 to 2019

Using more than three million Landsat satellite images, this research developed the first global impervious surface area (GISA) dataset from 1972 to 2019. Based on 120,777 independent and random reference sites from 270 cities all over the world, the omission error, commission error, and F-score of GISA are 5.16%, 0.82%, and 0.954, respectively. Compared to the existing global datasets, the merits of GISA include: (1) It provided the global ISA maps before the year of 1985, and showed the longest time span (1972–2019) and the highest accuracy (in terms of a large number of randomly selected and third-party validation sample sets); (2) it presented a new global ISA mapping method including a semi-automatic global sample collection, a locally adaptive classification strategy, and a spatio-temporal post-processing procedure; and (3) it extracted ISA from the whole global land area (not from an urban mask) and hence reduced the underestimation. Moreover, on the basis of GISA, the long time series global urban expansion pattern (GUEP) has been calculated for the first time, and the pattern of continents and representative countries were analyzed. The two new datasets (GISA and GUEP) produced in this study can contribute to further understanding on the human’s utilization and reformation to nature during the past half century, and can be freely download from http://irsip.whu.edu.cn/resources/dataweb.php.

     

杨山晚古生代沉积盆地成因类型及其与桐柏-大别造山带关系的探讨

杨山晚古生代沉积盆地位于桐柏-大别山北麓,它具有明显的前陆盆地沉积特点,由早期(D₂?—C₁)的复理石建造到晚期(C₁—P?)的磨拉石建造;古生物地理分析表明其与华北、扬子陆块都有密不可分的联系,其间不可能有古洋盆的存在,因而它应当是桐柏一大别造山带碰撞造山过程中形成的前陆盆地。杨山晚古生代前陆盆地的形成说明,扬子陆块和华北陆块的陆-陆碰撞起始于晚泥盆世之前(S₃—D₂),而桐柏-大别造山带中生代的构造事件则可能代表一次大规模陆内逆冲-推覆作用。     

参数的期望估计及其在形变分析中的应用

利用“参数的期望估计”能准确定位、定量粗差及参数的期望估计不受粗差影响折特殊性质,寻找地壳变形区域和不变形区域,以确定拟稳点,进而进行拟稳变换,分析地菜变,将是一种有效方法。     

Flux determination over a smooth surface under strongly unstable conditions

Careful micrometeorological measurements on an empty parking lot allowed determination of the surface fluxes of sensible heatH and of momentum by applying profile equations derived from Monin-Obukhov similarity theory with two sets of the stability correction function for momentum _m and sensible heat _h . These fluxes were compared with reference values ofH independently determined by means of an eddy correlation technique. In general, better agreement was found betweenH values derived from profiles with the stability functions of Brutsaert (1992) and referenceH values, than when the Businger-Dyer functions were used to deriveH. The disagreement in the latter comparison was especially serious under strongly unstable conditions, with the value ofy=–z/L (wherez is the height andL is the Obukhov length) larger than 10. A closer look at the procedure for calculatingH from the profiles revealed that the large differences between theH values derived with these two different versions of the stability correction functions were caused by the small differences of the _h values, and not by the larger differences of the _m values. This result stems from the strong sensitivity of the resultingH values on the choice of _h .     

合肥遥测台网地震速报系统

论述了适用于遥测地震台网大震速报的一套计算机处理系统,系统设计以《全国遥测台网观测技术规范》和《近震分析》理论为依据,实现了数据输入,震相选择,数据处理,地震定位,震级计算,结果输出及贮存等多项功能,达到了快速确定地震三要素,提高速报速度和精度之目的,是一个较完善的,实用的速报系统。     

地震前水氡短临异常判别指标及预报三要素的方法探讨

本文分析了中国大陆(重点是南北地震带北段)水氧异常变化,深入研究了有震与无震异常的时空分布特征、异常总频次、起始异常时间差等,发现有震异常往往呈现“同步性”或“群体性”特征,而大部分“零散性”异常则属于非地震异常。根据上述研究,本文还提出了利用水氡异常预报地震的发震时间、地点和震级的初步方法。     

Structural similarity and variety at the tips in a wide range of strike–slip faults: a review

Strike–slip faults are often accompanied by a variety of structures, particularly at their tips. The zones of additional fracturing are classified as tip‐damage zones. These zones can be subdivided into several different damage patterns based on the nature and orientation of faults and fractures developed. Damage zones at the ends of small strike–slip faults (mode II tips) develop wing cracks, horsetail splays, antithetic faults, synthetic branch faults and solution surfaces. Similar tip‐damage patterns are also commonly observed at larger (regional) scales, but with a dominance of faulting over tensile cracks and solution surfaces. Wing cracks and horsetail splays developed at small‐scale faults are replaced by normal faults in large‐scale faults. Antithetic faults and synthetic branch faults are observed at small and large scales. Thrust faults are developed at large scales, in a similar pattern to solution surfaces at a small scale. All these structures may show slightly different angular relationships to the master fault at small and large scale, but develop in response similar stress distribution and mechanics around the fault. Thus, mode II tip‐damage zones show similar patterns over a wide range of fault scales.