1961-2008年中国西南地区极端气候变化幅度的海拔效应(英文)

A total of 12 indices of temperature extremes and 11 indices of precipitation ex-tremes at 111 stations in southwestern China at altitudes of 285-4700 m were examined for the period 1961-2008. Significant correlations of temperature extremes and elevation in-cluded the trends of diurnal temperature range, frost days, ice days, cold night frequency and cold day frequency. Regional trends of growing season length, warm night frequency, coldest night and warmest night displayed a statistically significant positive correlation with altitude. These characteristics indicated the obvious warming with altitude. For precipitation extreme indices, only the trends of consecutive dry days, consecutive wet days, wet day precipitation and the number of heavy precipitation days had significant correlations with increasing alti-tude owing to the complex influence of atmospheric circulation. It also indicated the increased precipitation mainly at higher altitude areas, whereas the increase of extreme precipitation events mainly at lowers altitude. In addition, the clearly local influences are also crucial on climate extremes. The analysis revealed an enhanced sensitivity of climate extremes to ele-vation in southwestern China in the context of recent warming.     

Heavy metal contamination in western Xiamen Bay sediments and its vicinity, China

Concentrations of selected heavy metals (Cu, Pb, Zn, Cd, Cr, Ni and Fe) in surface sediments from nine sites in western Xiamen Bay and its vicinity were studied in order to understand current metal contamination due to urbanization and economic development in Xiamen, China. The sediment samples were collected in December 2004 and July 2005 respectively in order to examine temporal variations. In this study, we found that heavy metal concentrations in surface sediments sampled in the western Xiamen Bay and adjacent Maluan Bay and Yuandang Lagoon varied from 19 to 97mg kg(-1) for Cu, 45 to 60mg kg(-1) for Pb, 65 to 223mg kg(-1) for Zn, 0.11 to 1.01mg kg(-1) for Cd, 37 to 134mg kg(-1) for Cr, 25 to 65mg kg(-1) for Ni and 3.08 to 4.81% for Fe. Although all metal concentrations in sediments meets Chinese National Standard Criteria for Marine Sediment Quality, both metal enrichment factors (EF) and geoaccumulation index (I(geo)) show that Pb contamination exists in the entire study area and contamination of other metals are also present in some locations depending on the sources, of which sewage outlets and commercial ports are the main sources of contaminants to the area. This study shows that using the sediment quality standard criteria only to assess sediments cannot properly reflect sediment contamination. A multiple approaches should be applied for the sediment quality assessment.     

四川江油渔洞子飞仙关组巨鲕灰岩的成因解释——在微观及超微世界里认识华南早三叠世巨鲕灰岩的成因

作为错时相沉积之一的巨鲕灰岩在我国华南早三叠世地层中广泛出现,在寒武纪之后本已消失的这种沉积类型为什么会在早三叠世又重新出现?在四川江油渔洞子下三叠统飞仙关组鲕粒灰岩的底部,产有一套巨鲕灰岩,通过高倍显微镜及扫描电镜的深入研究,首次发现在巨鲕灰岩的鲕粒和围岩中充满丰富的疑似底栖蓝细菌、疑似颗粒状浮游蓝细菌及其他超微化石。根据这些疑似底栖蓝细菌的结构和构造特点,可以划分出下列几种类型:疑似蛛网状蓝细菌,疑似微球状蓝细菌,疑似网格状蓝细菌,疑似蠕虫状蓝细菌,疑似直管状蓝细菌,疑似链状蓝细菌,疑似花瓣状蓝细菌和Renalsis,疑似颗粒状浮游蓝细菌(主要有两种类型:简单的椭球粒和螺旋状球粒)。超微化石包括钙球和铃铛形超微化石。疑似底栖和浮游蓝细菌及其他超微生物的大量繁盛,是二叠纪-三叠纪之交海洋生态环境恶化、海洋底栖动物大灭绝所产生的后果。这一发现不仅使我们在微观世界和超微世界里重新认识巨鲕灰岩的成因,它是生物和沉积两种主要因素共同作用的结果,从而对巨鲕灰岩的时代分布做出了很好的解释;同时,也可以帮助我们重塑当时该地区的海洋古生态系统。     

卡斯凯迪亚消减带的幕式颤动和滑动：静滑动震颤

发现在最初被认为不活动的北卡斯凯迪亚消减带的深部界面观测到的重复性缓慢滑动事件具有独特的非地震性地震学特征。颤动状的地震信号与用跨越过去6年的地壳运动数据识别出的滑动事件在时间和空间上相关。在滑动事件之间的时段内，颤动活动要么不存在，要么很小。我们称这种颤动和滑动相关现象为幕式颤动和滑动(ETS)。我们认为幕式颤动和滑动的活动可以作为卡斯凯迪亚特大逆冲地震区应力加载的实时指标。     

冀中饶阳凹陷大王庄地区古近系沉积演化特征与储盖组合分析

冀中饶阳凹陷大王庄地区古近系属断陷湖盆演化阶段,分为断陷分割期、断陷扩张期和断陷萎缩期3个时期,发育辫状河三角洲、滨浅湖和曲流河3类沉积体系。在等时地层格架内,分析了该地区沉积演化特征和储盖组合的分布及时空展布规律,指出该区古近系主要发育沙三段、沙二段、沙一段和东营组4套储盖组合,其中沙一段储盖组合为最有利的含油储盖组合。     

Nature Communications:地表侵蚀作用可能引发地震

正11月21日,Nature Communications刊登文章《侵蚀作用影响活动断层的地震活动性》(Erosion Influences the Seismicity of Active Thrust Faults),来自中国台湾和法国的研究团队经研究指出,地表的侵蚀作用可以对于活动断层造成显著的应力变化,进而影响地震活动的发生。长期以来,科学家们一直怀疑地表的侵蚀作用(包括河川的侵蚀搬运等)可能会影响地壳深部的应力平衡,进而影响地震活动的发生。然而过去由于缺乏数据,这个假设一直无法得到证实。来自台湾和法国的研究团队利用过去针对台湾地区活动断层调查所得的数据,搭配文献中记录的台湾地区侵蚀速率,运用力学模型仿真的方法,成功证明板块构造并非是能够影响地震断层活动的唯一机制,地表的侵蚀作用可以对活动断     

Detection and isolation of p-nitrophenol-lowering bacteria from intestine of marine fishes caught in Japanese waters

To determine the existence of p-nitrophenol (PNP)-lowering bacteria in intestine of Japanese coastal fish, the gastro-intestinal contents were incubated in Brain Heart Infusion (BHI) broth and minimal medium (MM) broths containing 1 mmol/L PNP at 30 °C for 7 days. Among 26 samples of 19 fish species, 17 samples showed a decrease in PNP of 0.5-0.8 mmol/L in BHI broth, but no decrease was shown in MM broth. Eighteen PNP-lowering bacterial strains were isolated from four fishes. All of the strains were identified as Lactococcus lactis subsp. lactis. Three L. lactis strains JS1-3 isolated from Japanese seabass Lateolabrax japonicus showed the highest PNP-lowering activity (0.44 mmol/L). Optimum temperature and pH for the growth and PNP decreasing corresponded with the marine environment. These results suggested that marine fishes have PNP decreasing bacteria in their intestine. These bacteria might protect host fish from toxicities of PNP and PNP related compounds.     

天然水中矿物溶解度的预测——25℃时高离子强度的Na-K-Mg-Ca-H-Cl-SO_4-OH-HCO_3-CO_3-H_2O体系

Harvie和Weare(1980)的矿物溶解度模型,被扩展到25℃时高浓度的8组份体系Na-K-Mg-Ca-H-Cl-SO_4-OH-HCO_3-CO_3-CO_2-H_2O。该模型就其水电解质溶液的热力学而言,是以Pitzer(1973)及其同事们的半经验公式为基础的。利用大量的适用于大多数亚体系的有效的等压、电动势及溶解度资料,把模型参数化。模型的推测能力,已通过体系中比参数化所用资料更为复杂的实验资料进行对比而证实。本文讨论了水电解质溶液的化学模型的基本特点和pH与溶液平衡特性之间的关系。     

使用指数密度-深度函数对沉积盆地的重力资料进行三维解释

在用重力模型绘制深部沉积盆地基地的地形中,结合密度随深度按指数函数增加的关系可以改善其精度。为了计算具有这种指数密度-深度关系的三维构造的重力效应,提出了一种以级数展开为基础的频率域正演算法,其数值计算可以用快速傅里叶变换完成。在递归程序中可以应用此算法,以便依据基底起伏来给出反演解。在澳地利东部的潘诺宁(Pannonian)盆地西缘得到的重力资料的二维合成例子和三维野外例子令人满意地检验了这种反演程序,盆地内厚达2.2km的三迭纪沉积物上覆在火成岩或变质岩基底上。几个井内的基地相交证实了这些结果。