Origin of abundant moonmilk deposits in a subsurface granitic environment

Subsurface granitic environments are scarce and poorly investigated. A multi‐disciplinary approach was used to characterize the abundant moonmilk deposits and associated microbial communities coating the granite walls of the 16th Century Paranhos spring water tunnel in Porto city (north‐west Portugal). It is possible that this study is the first record of moonmilk in an urban subsurface granitic environment. The morphology and texture, mineralogical composition, stable isotope composition and microbial diversity of moonmilk deposits have been studied to infer the processes of moonmilk formation. These whitish secondary mineral deposits are composed of very fine needle‐fibre calcite crystals with different morphologies and density. Calcified filaments of fungal hyphae or bacteria were distinguished by field emission scanning electron microscopy. Stable isotope analysis revealed a meteoric origin of the needle‐fibre calcite, with an important contribution of atmospheric CO ₂, soil respiration and from weathering of Ca‐bearing minerals. The DNA ‐based analyses revealed the presence of micro‐organisms related to urban contamination, including Actinobacteria, mainly represented by Pseudonocardia hispaniensis , Thaumarchaeota and Ascomycota, dominated by Cladosporium . This microbial composition is consistent with groundwater pollution and contamination sources of the overlying urban area, including garages, petrol stations and wastewater pipeline leakage, showing that the Paranhos tunnel is greatly perturbed by anthropogenic activities. Whether the identified micro‐organisms are involved in the formation of the needle‐fibre calcite or not is difficult to demonstrate, but this study evidenced both abiotic and biogenic genesis for the calcite moonmilk in this subsurface granitic environment.     

Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales

“Southern Resident” killer whales include three “pods” (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as “endangered” in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. ∑PCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993–1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of ∑PBDEs, ∑HCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.     

磁变仪布局的研究

本文提出了改进磁变仪布局的必要性和布局标准,对磁变仪定向及其稳定性、标度值稳定性和分量仪间允许的最小间距进行了研究,提出了可以提高磁变仪记录质量的改进布局和满足布局全部标准的新布局,改进布局特别是新布局可以显著提高磁变仪保持定向、抗干扰能力,获得记录标度值稳定的较理想的磁照图。     

CT引导下肺部穿刺活检的应用分析

本文的目的是分析和评价ＣＴ引民下肺部穿刺活检中体位的选择,穿刺点定位,穿刺针及穿刺方式等因素对本项检查结果的影响。所用材料与方法：回顾性分析分析３６例完整的病例,分别统计了切割法和抽吸法的阳笥率,假阳性率,假阴性率,气胸率及局部出血发生率组织诊断率。得到结论为切割法较抽吸法能获得更高的阳性率和组织学诊断率,但局部少量出血发生率略高     

The orientation of sorted stripes in the maritime subantarctic,Marion Island

The orientation of sorted stripes developed in glacial deposits on Marion Island is examined. This study confirms earlier reports of preferential occurrence of sorted stripes on windward slopes. However, sorted stripes were also found to occur on low angle leeward slopes. Mechanisms for the orientation of sorted stripes by wind action are discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

一种红色砭石的矿物学特征研究

采用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）、热重分析（TG-DTG）及激光诱导离解光谱（LIBS）等分析方法对一种红色砭石的矿物学特征进行了深入的研究。XRD分析表明,红色砭石主要由白云石组成,并含有少量石英和方解石及微量云母、正长石和赤铁矿。SEM结果显示,砭石中的矿物颗粒大多为集合体,粒径大多集中在1～5μm之间,表面光滑程度有所不同。红色砭石在650-850℃范围内出现一个单失重峰,为白云石的分解形成,类质同象或者杂质矿物的存在导致白云石两阶段的分解同步完成。红色砭石的颜色可能与赤铁矿和正长石微晶在砭石中的均匀分布有关。     

卫星天线的单片机快速对星系统

使用GPS接收机模块得到卫星天线所在位置的经纬度,单片机模块进行数据处理得到对星所需要的方位角、仰角,与电子罗盘测得的天线的方位角、仰角进行比较得到其差值,并用液晶显示模块将其结果全部显示出来,指导天线操作人员实现快速、准确对星。     

锚杆在泥石流防治工程中的应用前景

从锚杆的工作原理出发 ,探讨锚杆在泥石流防治工程中应用的可能性。认为锚杆可以增加重力坝或格栅坝的稳定性 ,大幅度减少重力坝或格栅坝的工程量 ,应用前景广阔。介绍新型回收式锚杆的特点 ,并提出移动式格栅坝的设想     

Cytochrome P450 1A1 expression in cetacean skin biopsies from the Indian Ocean

The study describes cytochrome P450 1A1 (CYPA1) expression in the skin of different cetacean species (Megaptera novaeangliae, n = 15; Stenella attenuata, n = 7 and Stenella longirostris, n = 24) from the Mozambique Channel island of Mayotte. Immunohistochemical examination was performed with a monoclonal antibody against scup cytochrome CYPA1. The sex was determined using a molecular approach consisting in the genotyping sex-specific genes. CYPA1 was detected at the junction between epidermis and blubber on dolphins only, mostly in the endothelial cells. Similar observation was obtained in the dermis of one M. novaeangliae. Immunohistochemical slides were scored to evaluate the expression of the CYPA1 and a higher expression was observed in S. longirostris, suggesting a higher exposure to pollutants for this species. The difference of expression between sexes was not significant.