Regional and temporal changes in bivalve diversity off the south coast of Portugal

From 2000 to 2006, a total of 75 bivalve species were identified, varying from 29 (spring 2001) to 54 species (spring 2005) per year. Seasonal tendencies in diversity varied according the year, thus the interpretation of long-term and regional scales is essential before drawing any conclusions in other studies. Richness and diversity consistently decreased with depth and increased with sediment grain size (from low in very coarse sand to high in coarse silt). Diversity decreased progressively from 3 to 16 m depth, thus the harsher shallower environments (due to waves and tidal air exposure) showed greater diversity than the most stable areas. Communities in finer sediments were more diverse than those in coarser sand. Evenness showed patterns opposite to diversity, overall.Diversity and evenness maps (produced with multivariate universal kriging), showed that most geographic areas with greater diversity were farer from river outflows and wastewater treatment plants. Two types of geographic pattern were observed: areas with persistently greater bivalve diversity through time and areas that changed locally from year to year. This spatial analysis can be used to establish priority conservation areas for management purposes, and to analyse the persistency of regional diversity patterns. The area with most habitat heterogeneity (Sotavento) corresponded to greatest diversity.There was a positive relationship between Spisula solida and Chamelea gallina landings and bivalve diversity 2 years and 1 year later, respectively. Possibly, local fisheries, by selectively withdrawing the commercial numerically dominant species from the ecosystem, increased diversity 1 to 2 years later, as the ecological niches of the dominants are quickly filled by several other species thereby creating a more even community. On regional scales, no significant impact was found on long-term bivalve diversity in local fisheries,     

巴黎大都市区商业的发展及其新近的变化

阐述了近二十年来巴黎大都市区商业所经历的巨大增长和迅速变化。     

复杂构造应力扰动场与发震构造识别问题的研究

在地震短临阶段异常是由局部断层扩展或弱化引起。实验与数值模拟结果曾得到与之相伴的是平均应力扰动场的四象限分布和最大剪应力扰动场的八瓣式分布。为检验此结果的普适性作了进一步的研究。结果表明不论区域构造及其基本应力场如何复杂，这种四象限分布与八瓣式分布型式不变，这为最终判定失稳区提供了依据。与此同时，在复杂构造情况下这种应力扰动场的畸变也不容忽视     

内蒙古霍林河煤田内蒙古拟刺葵(新种)Phoenicopsis (Phoenicopsis) neimengensis sp.nov.的首次发现

笔者首次发现了内蒙古霍林河煤田霍林河组(K1h)茨康类拟刺葵属拟刺葵亚属的一个新种—内蒙古拟刺葵(Phoenicopsis(Phoenicopsis)neimengensis sp.nov.)。该新种以表皮构造下气孔式,上表皮细胞未见乳突,下表皮普通表皮细胞发育中央乳突,气孔器副卫细胞多发育乳突,孔缝不定向等特征区别于拟刺葵属已知种。新种的研究对于了解拟刺葵属(Phoenicopsis)的分类,以及恢复古地理、古气候有重要作用。     

玉树断裂活动性研究

通过实地考察和室内工作，对玉树断裂的活动性进行了分段研究。该断裂划分为３段：（１）西北段全新世以来活动强烈，以水平左旋活动为主，水平滑动速率达７．３ｍｍ／ａ，沿断裂带展布大量的古地震事件遗迹；（２）中段第四纪以来的主体活动时段在晚更新世以前，以正断层活动为主；（３）东南段全新世以来活动强烈，以水平左旋活动为主，水平滑动速率约５ｍｍ／ａ，沿断裂带分布有大量的古地震事件遗迹，历史上记载的最大地震为１８９６年的邓柯７．０级地震     

Performance of the stereoscopic system of the HEGRA imaging air erenkov telescopes: Monte Carlo simulations and observations

Based on the Monte Carlo simulations we have studied the performance of the HEGRA system of imaging air erenkov telescopes (IACTs) in its present configuration of 4 IACTs as well as in its future final configuration of 5 IACTs. Here we present the results on the basic characteristics of the IACT system which are used in the standard data analysis procedure, i.e., the collection areas, the detection rates, the angular resolution, the energy resolution, and the γ/hadron-separation efficiency. By comparing several key Monte Carlo predictions with experimental results it is possible to check the accuracy of the simulations. The Monte Carlo results concerning hadron-nuclear showers are tested with the recorded cosmic ray events and the results concerning photon-induced showers are tested with a large data sample of γ-rays observed from BL Lac object Mkn 501 during its high flaring activity in 1997. Summarizing the simulations and current observations we give the basic recommendations of using the instrument and the major values of its sensitivity.     

上海覆盖区活断层

应用物、化探相结合的方法，首次证实了广为第四纪松散沉积层（平均厚度达２４０ｍ）所覆盖的上海地区存在着第四纪活断层，并对其基本特征和活动情况作了初步论述     

华北隐伏活动断裂H＿2异常特征及其异常机制研究

在华北北部３条断裂活动性和地震活动性差异较大的隐伏断裂上取５４个土壤气样品。经对比研究发现，隐伏活动的唐山断裂和夏垫断裂上，Ｈ２异常显著，一般比背景值高几十倍；而隐伏不活动的香河－皇庄断裂上，Ｈ２则没有异常。在探讨隐伏活动断裂Ｈ２异常机制中，认为Ｈ２不是生物作用的产物，而是来源于结晶基底片岩、片麻岩等的破裂或水岩反应。不论Ｈ２来源如何，它都与断裂活动密切相关     

抚顺市煤矸石对生态环境的影响及综合利用

抚顺市煤田开采悠久，煤矸石的堆积量大，对生态环境的影响显著，并且占用大量土地，严重污染环境，以及出现边坡失稳现象。本文详细地分析了煤矸石对生态环境的影响，阐述了目前煤矸石资源化的综合利用情况，以及开发利用煤矸石具有环保和经济双重意义。     

网上零售企业的空间组织研究——以"当当网"为例

零售商业活动及其空间组织历来是城市和经济地理学研究的重要主题之一.伴随着新的信息和通信技术的应用和普及,一种新的商业业态--网上购物,正在被越来越多的商家和消费者所接受.这一趋势对零售业的价值链、商业模式以及空间组织均产生了不可忽视的影响.本文试图通过对国内主要的电子商务企业之一"当当网"的研究,初步探讨网上零售企业的...