绕射波在坑道中超前探测小构造的应用

本文阐述了应用绕射波探测坑道掌子面前方小构造的技术,在速度低于上下围岩的中等速度的特定层位中,地震波将在前方的小断层或小构造处反射,以绕射波形式返回到检波器,其最远的探测距离达184m。     

软岩弹性模量的测定与讨论

本文首先介绍一种岩土自动化精密三轴压缩试验系统,并以此试验系统所得的一组实验结果为例,揭示软岩在微小应变(ε_1=10~(-2)—10~(-5))条件下所反应的应力-应变的线性关系,以及根据软岩在弹性范围内所测得的数据求出弹性模量。本文结合以往的研究成果,对软岩的弹性模量及变形系数开展分析和讨论。最后,本文将实验结果与现场测试结果相比较,从中了解两者之间的关系。     

晚期小岩体归宿及其在找矿中的意义初探

本文提出了晚期小岩体不是花岗岩浆演化的产物,而是相当于超浅成的次火山岩。由于它与铀成矿关系密切,因而花岗岩型铀矿与火山岩型铀矿成矿机理相同。对比火山岩中两大系列铀矿,即与次火山岩有关的早期铀矿和与红盆发生发展有关的晚期铀矿,认为花岗岩中也应有相应的两期铀矿。今后找富矿、找深部矿时应注意寻找早期铀矿。同时根据花岗岩中面型蚀变体的存在,推论在面型火山岩铀矿深部应寻找次火山岩型铀矿。     

Measuring Demographic Change: The Split Tract Problem

Census tracts in rapidly growing areas often are split into two or more tracts between decennial censuses. The mismatch of tract boundaries between decades poses difficult problems for those researchers interested in measuring demographic change in small areas. The most common solution is to make tracts in both years conform to the earlier boundaries-data from the split tracts are aggregated. An alternative is to apportion data for the earlier year on the basis of land area. A third method estimates the distribution of data for the earlier year by the proportion of population later living in the various split tracts. Comparison of these three methods suggests that, in typical situations, the latter method results in less overall error.     

普查小型矿床时的研究程度问题初议

小型矿床开发利用在我国矿业中占有十分重要的地位。但小型矿床一般只经过普查工作，研究程度低。如何利用普查资料进行小型矿山建设，又不致造成大的失误？这是一个十分现实的问题，本文对其进行了初步探讨。     

小流域水土保持效益的灰色预测分析：以鹿马岔实验区为例

水土保持效益指标是一个多目标、多因素的动态灰色控制系统，其时间序列的动态变化可以用灰色控制理论中的灰色模型进行定理分析与预测。根据对鹿马岔小流域产业结构和经济潜力的分析，其预测值是可信的，从而证明了灰色系统理论是小流域水土保持综合治理效益预测实现模型化、定量化的有效方法之一。     

河口冲淡水运动理论模式及数值应用(续)——(Ⅱ)数值应用

2 计算结果和讨论2.1区域特征和参数选取 具体数值模拟在图2区域上进行。区域水平尺寸为60×80km;河口口门宽5km、深5m;计算网格间距△x=△y=2.5km。海底底形考虑图3类型。其它参数取值在后面的流函数分布图中予以说明。     

A coastal reservoir of terrestrial resources for neanderthal populations in north‐eastern Iberia: palaeoenvironmental data inferred from the small‐vertebrate assemblage of Cova del Gegant,Sitges, Barcelona

Coastal areas as reservoirs of resources for hominid groups have been widely studied in recent years. These areas combine marine with terrestrial and wetland resources and would have been optimum sites for hominids, including Neanderthals. This is the case with the Cova del Gegant, a cave that today opens directly onto the Mediterranean Sea and is located in the north‐eastern Iberian Peninsula. The geomorphological evolution of the Massis del Garraf has provided evidence that during the late Pleistocene there was a littoral platform between 8 and 13 km wide in front of the Cova del Gegant. Within this framework, the data derived from analysis of the small vertebrates and large mammals recovered from Cova del Gegant, including taxa currently absent from the Massis del Garraf, suggest that the landscape surrounding the cave provided a richer terrestrial ecosystem for Neanderthals than is available in this zone today. Analysis of the small‐vertebrate association from the cave reveals that the landscape surrounding the cave was dominated by woodland‐edge and open environments and that the climate was Mediterranean. The results have been compared with the only Iberian site with similar characteristics to the Cova del Gegant, Gorham's cave (southern Iberia, Gibraltar), revealing differences and similarities in the landscape and climate on the basis of the small‐mammal assemblages as well as the differences in the accessibility to terrestrial mammalian resources for the Neanderthal groups. The landscape and the climate were reasonably similar at the two sites, but the differences in the accessibility of resources for the Neanderthals are directly related to the location of the sites and the coastal position. Whereas the Cova del Gegant was on a route of mammal migration (between the Ebro Valley and France) suited for securing terrestrial resources, Gorham's cave is located on a small peninsula with a lower abundance of terrestrial mammal resources. This is probably why the Neanderthal groups at Gorham's cave exploited marine resources, whereas there is no evidence of marine resources having been exploited at Cova del Gegant, even though the seashore was nearby. Copyright © 2011 John Wiley & Sons, Ltd.