The First Appearance of Cattle in Denmark Occurred 6000 Years Ago: An Effect of Cultural or Climate and Environmental Changes

Stable carbon and nitrogen isotope ratios from bones of contemporaneous Late Atlantic aurochs and early cattle in eastern Denmark are significantly different and provide information on the origin and feeding strategies of the earliest domestic cattle. The data show that the early cattle were feeding on grass right from the beginning 4000 cal. yr BC. In contrast, the youngest aurochs population primarily browsed and grazed from the dense forest floor resulting in rather negative δ¹³C values measured on bone collagen. The oldest aurochs have similar isotope values to the earlier cattle, whereas the youngest aurochs have similar values to Late Atlantic red deer from the same locality. As eastern Denmark was largely covered by forest, speculations on the origin of the grazing areas are many. The grass may have grown in openings in the forest, at the forest fringe, or more likely on the newly reclaimed coastal land areas exposed by the decreasing rate of eustatic sea‐level rise contemporaneously with isostatic uplift, during the Littorina transgressions. The stable isotope values do not indicate that leaf foddering of the early cattle was of importance.     

Synchrotron IR study of hydrous ringwoodite (γ-Mg2SiO4) up to 30 GPa

High-pressure synchrotron infrared (IR) absorption spectra were collected between 650 and 4,000 cm⁻¹ at ambient temperature for hydrous Mg-ringwoodite (γ-Mg₂SiO₄) up to 30 GPa. The main feature in the OH⁻ stretching region is an extremely broad band centred at 3,150 cm⁻¹. The hydrogen bond is strong for most protons and the most probable site for protonation is the tetrahedral edge. With increasing pressure, this band shifts downward while decreasing its integrated intensity until disappearance at a pressure of 25 GPa. Only one band at 2,450 cm⁻¹ and an absorption plateau persist with a maximum wavenumber of 3,800 cm⁻¹. This behaviour is reversible upon pressure release. We interpret this as a second-order phase transition occurring in hydrated Mg-ringwoodite at high pressure (beyond ∼ 25 GPa). This result is compatible with the observation by Kleppe et al. (Phys Chem Miner 29:473–476, 2002a) who suggested the presence of Si–O–Si linkages and/or partial increase in the coordination of Si. Beyond the phase transition, the protons are delocalized and their environment on the ringwoodite structure is probably quite different from that at low pressure. Data obtained in situ at high pressures and temperatures are needed to better understand the effect of protonation on the structure and to better constrain this phase transition.     

古—中生代之交的全球变化与生物效应

古—中生代之交是显生宙以来最大的一次生物绝灭期 ,其形成机制一直是地学界长期探讨的热点课题之一。地史重大转折期是地球内、外各圈层长期作用下 ,各种量变达到阀值 ,加之可能的外因激化 ,在短时间内以连锁反应形式相继质变 ,形成了全球变化 (包括生物绝灭 )的地球突变期。文中从可能的外因 (外星体撞击事件 )及内因 (岩石圈的变化 ,地球表层的变化和生物圈的变化 )两个方面探讨了古—中生代之交的全球变化与生物效应     

Labour markets in transition. The experiences of women in two border regions of East Germany

The political turning point in the former GDR and the transformation processes that have been observed since then have significantly affected economic and social structures in the new Federal States. Gender roles, however, were subjected to even more dramatic changes. Whilst many women experienced the employment policies of the GDR era as beneficial, social researchers often designate them as the losers of unification nowadays. This is largely because the abundance of State support measures for employed women and mothers has been drastically reduced and women as a group have been hit hardest by the crisis on the East German labour market. Using two cases (Mecklenburg-Westpommerania and Thuringia), this paper aims to illustrate the impact of the transformation process on the everyday (working) lives of women. We are particularly concerned with a comparative analysis of how women experience and deal with regional disparities in East Germany. This revised version was published online in July 2006 with corrections to the Cover Date.     

The eastern Tonale fault zone: a ‘natural laboratory’ for crystal plastic deformation of quartz over a temperature range from 250 to 700 °C

Near the eastern end of the Tonale fault zone, a segment of the Periadriatic fault system in the Italian Alps, the Adamello intrusion produced a syn-kinematic contact aureole. A temperature gradient from 250 to 700 °C was determined across the Tonale fault zone using critical syn-kinematic mineral assemblages from the metasedimentary host rocks surrounding deformed quartz veins. Deformed quartz veins sampled along this temperature gradient display a transition from cataclasites to mylonites (frictional–viscous transition) at 280±30 °C. Within the mylonites, zones characterized by different dynamic recrystallization mechanisms were defined: Bulging recrystallization (BLG) was dominant between 280 and 400 °C, subgrain rotation recrystallization (SGR) in the 400–500 °C interval, and the transition to dominant grain boundary migration recrystallization (GBM) occurred at 500 °C. The microstructures associated with the three recrystallization mechanisms and the transitions between them can be correlated with experimentally derived dislocation creep regimes. Bulk texture X-ray goniometry and computer-automated analysis of preferred [c]-axis orientations of porphyroclasts and recrystallized grains are used to quantify textural differences that correspond to the observed microstructural changes. Within the BLG- and SGR zones, porphyroclasts show predominantly single [c]-axis maxima. At the transition from the SGR- to the GBM zone, the texture of recrystallized grains indicates a change from [c]-axis girdles, diagnostic of multiple slip systems, to a single maximum in Y. Within the GBM zone, above 630±30 °C, the textures also include submaxima, which are indicative of combined basal a- and prism [c] slip.     

Al hematites prepared by homogeneous precipitation of oxinates: material characterization and determination of the Morin transition

A novel method for synthesis of aluminium hematites, based upon the homogeneous precipitation of Fe and Al oxinates in various proportions, is presented. The precursor precipitates are heated in air at 700?°C. X-ray diffraction, thermal analyses, BET, FTIR, optical reflection analysis, TEM and Mössbauer spectroscopy at room temperature and 80?K of the resulting products indicate that single-phase hematites are formed with structural Al substitution of up to 10 at%. Interestingly, the particle size (>100?nm) is not substantially reduced by the Al content. Although it remains difficult to obtain a homogeneously distributed Al substitution in the final hematite, this processing line offers a unique opportunity to separate the effects of grain size and Al substitution on the Morin transition temperature (T _M) of Al hematite. From the comparison between the present hematites and a series of Al-substituted hematites with lepidocrocite as precursor, it could be shown that the effect on T _M, associated with a change of a factor 10 in grain size, is about 1/3 of the effect caused by a change of 10 in the degree of substitution. Finally, it is suggested that proper thermal treatments under different conditions of the same precursors are likely to produce spinel phases.     

软基上高速铁路路桥过渡段的技术措施研究

通过对高速铁路路基与桥梁过渡段动力特性分析，指出结构物沉降差是导致轨面不平顺的主要因素。分析了沉降差产生的原因，提出了软基上路桥过渡段的结构设计方案，并对其施工方法及质量检测标准进行了探索。     

浅论新疆海相火山热水沉积矿床的分带及其找矿意义

新疆海相火山热水沉积矿床，一般在时间上没有明显的集中生长期。空间上依附于活动大陆边缘火山岛弧带，它在区域上和矿床本身具有矿种转化、类型转换、配套与分带特征。以块状氧化物、块状碳酸盐和块状硫化物转换序次来研究该类矿床。利用铁木尔特铅锌矿上部铅锌下部铜金，预须开普台铁矿上铁下铜；莫托沙拉铁锰矿上锰下铁中间铅锌重晶石等矿种转化规律和由块状氧化物和块状碳酸盐向块状硫化物成生过渡特点，预测诸如蒙库铁矿、赤龙峰火山盆地中铁矿和喀喇昆仑山各铁矿床(点)外围与深部转换、发展成为铜金矿的成矿前景。     

论上海软土地基⑦⑧⑨层压缩模量Es的定值问题

上海地区深部土层⑦⑧⑨层埋深在30～70m。对其压缩模量Es的定值问题,现行《上海市地基基础设计规范》(DGJ08 11 1999)(后文中简称《规范》)长期以来确定室内试验E0 1～0 2值为沉降计算值,导致沉降计算值与建(构)筑物实际沉降量之间相差2～8倍。为符合规范的变形要求,设计人员不得不采取桩加粗、加长、加密的办法,从而造成桩基投资的极大浪费。为了正确认识深部土层的Es值,上海岩土工程界进行了多种形式的试验研究。近年来,笔者结合上海高、大、深、重建(构)筑物的工程实践,深入进行上海深部⑦⑧⑨层压缩模量Es的试验研究,获得许多新的认识,对其定值问题作了研究,提出⑦⑧⑨层的建议值,供同行参考研讨。     

时态GIS初探

时态GIS是GIS一个新兴的研究领域，目前仍处于理论与模型的研究阶段。章总结了时态GIS的研究现状，介绍了时间数据库与时空数据库的概念以及类型。在已有的研究成果基础上，归纳了时态GIS的主要功能，应包括输入、存储、编辑和更新，时空数据库管理，查询和检索，时空分析，显示和输出等功能模块。并提出了基于传统GIS解决时间方面问题的一些思路。