Use of chemical tracers in assessing the diet and foraging regions of eastern North Pacific killer whales

Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers-stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles-were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n=84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.     

地质雷达：第四纪沉积物中发射频率与最大穿透深度的关系

在美国犹他州Ｂｒｉｇｈａｍ市附近的采石场进行了地质雷达试验，确定２５ＭＨｚ，５０ＭＨｚ，１００ＭＨｚ，２００ＭＨｚ频率的最大穿透深度，发现该沉积地区环境（富含石英质的，厚倾斜砾石层）最适合作试验区。试验时，使用１０００Ｖ的发射机，２５ＭＨｚ天线能探测到５２ｍ深，也可能达５７ｍ深地层，５０、１００、２００ＭＨｚ天线分别在４７、３７、２８ｍ深时信号大量损失，阻碍有效地探查地层界面，经２５０个不同地区的     

大别山地区是地体拼合区

地体是指以深大断裂为边界的,具有区域规模的地质实体,以不同于毗邻地体的地质发展史为特征。地体之间地质面貌截然不同,不存在任何过渡岩相带。这一理论成功地解释了滨太平洋地区的一些地质现象。笔者依据在大别山地区多年工作所积累的资料,认为这一地区实际上是一个地体拼合区,在地史时期发生过复杂的地体运动。依据区域沉积特征、古生物面貌,构造特征、岩浆活动、变质作用和其它特征的不同,可以判定本区存在着三个独立地体:大别地体、随应地体和北淮阳地体。它们以深大断裂为界,拼贴于华北地体,扬子地体和皖东地体之间。     

南太平洋辐合带（SPCZ）研究评述

本文评述了与南太平洋辐合带（ＳＰＣＺ）及其相伴云带有关的环流特征：ＳＰＣＺ的位置、结构和特征；其存在的理论和观测事实；ＳＰＣＺ在全球大气环流中的重要性；其位置和强度和准周期变化；在其影响区域内天气尺度系统的特征（如气旋、副热带急流）。     

Electrokinetic migration of permanganate through low-permeability media

This research was conducted to evaluate the combination of electromigration and potassium permanganate as a potential remediation method for low-permeability media (e.g., soil and sediment) contaminated with dissolved and sorbed organic contaminants. The experimental procedure was composed of two stages: determination of migration rates of permanganate through homogeneous cores and a primarily qualitative analysis of migration in more heterogeneous, two-dimensional scenarios. Results indicated that transport of permanganate through fine-grained porous media and clays can be undertaken using electromigration, and electromigration rates were found to be at least 400% faster than diffusion alone. In addition, the use of an applied electric field in a flushing scenario was shown to result in almost 100% sweep efficiency of a domain consisting of clay blocks interspersed in a glass bead medium. The results of the study show that there is potential for this method to be able to deliver permanganate and other potential remedial agents to treat contaminated zones within heterogeneous and low-permeability porous media through in situ chemical oxidation or other processes.     

地体学说——一种新兴的大地构造理论

从七十年代中期开始,随着大陆边缘地质工作的深入开展和古地磁学方法的广泛应用,首先在北美西部科迪勒拉地区诞生了一种新的大地构造理论——构造地层地体理论(简称地体理论).以后,在美、加、日、澳等国学者共同努力下,很快使这一学说推广到了北起阿留申群岛,南至南极大陆的整个环太平洋地区.在原来认为均一的构造岩相