苏南江阴-嘉定断裂带断层泥扫描电镜研究及其地震地质意义

本文在分析苏南江阴-嘉定北西向断裂带宏观构造特征的基础上,对断层泥中石英碎砾表面溶蚀结构进行了扫描电子显微镜研究,并与郯-庐断裂带山东段断层泥进行了电镜图象的对比分析,从而确定了江阴-嘉定断裂带的相对(最新)活动年代及其地震活动性;此外,就江阴-嘉定断裂带不同区段活动年代差异及其纵向迁移模式、断层泥石英碎砾表面结构电镜图象聚类的概率分布特征及其地震地质意义等有关问题展开了讨论     

Great new insights from failed experiments,unanticipated results and embracing controversial observations

Experimental data and observations, whether telescopic or analytical, are never wrong, though data derived from such sources can be misinterpreted or applied inappropriately to derive conclusions that are incorrect. Given that nature always behaves according to the laws of physics and chemistry, rather than according to currently popular models and theories, experimental results should always be considered correct even when the results are far from those that one might initially expect. We discuss a number of cases where the results of experiments, even one carried out as a simple calibration measure, produced wildly different results that generally required many years of effort or contemplation to understand. On the positive side, exploration of the circumstances that produced the “errant” results often led to new and interesting insights concerning processes that might occur in natural environments and that were well worth the effort involved.Specifically, we show how an experiment that “failed” due to a broken conductor led to experiments that made the first refractory oxide solids containing mass independently fractionated oxygen isotopes and to 1998 predictions of the oxygen isotopic composition of the sun that were confirmed by the analysis of Genesis samples in 2011. We describe a calibration experiment that unexpectedly produced single magnetic domain iron particles. We discuss how tracking down a persistent source of “contamination” in experiments intended to produce amorphous iron and magnesium silicate smokes led to a series of studies on the synthesis of carbonaceous grain coatings that turn out to be very efficient Fischer–Tropsch catalysts and have great potential for trapping the planetary noble gases found in meteorites. We describe how models predicting the instability of silicate grains in circumstellar environments spurred new measurements of the vapor pressure of SiO partially based on previous experiments showing unexpected but systematic non-equilibrium behavior instead of the anticipated equilibrium products resembling meteoritic minerals. We trace the process that led from observations of the presence of crystalline minerals detected in the comae of some comets to the 1999 prediction of large-scale circulation of materials from the hot, innermost regions of the solar nebula out to the cold dark nebular environments where comets form. This large-scale circulation was ultimately confirmed by analyses of highly refractory Stardust samples collected from the Kuiper Belt Comet Wild 2. Finally we discuss a modern and still unresolved conflict between the assumptions built into three well known processes: the CO Self Shielding Model for mass independent isotopic fractionation of oxygen in solar system solids, rapid and thorough mixing within the solar nebula, and the efficient conversion of CO into organic coatings and volatiles on the surfaces of nebular grains via Fischer–Tropsch-type processes.     

云南西北部丽江—剑川地区古近纪宝相寺组石英砂颗粒表面特征

石英砂具有丰富的颗粒表面特征,是判别沉积环境的重要标志。利用扫描电镜对云南丽江—剑川地区宝相寺组（E2b）的石英砂颗粒表面特征进行了系统分析：下部样品具水成特征,中部样品具风成特征,上部样品则具经水流改造后的风成特征。结合野外观察结果,从宝相寺组石英砂颗粒表面特征的变化规律可以看出,下部为近源洪积环境、中部为风成沙丘环境、上部为湖泊环境。其中中部样品的石英砂磨圆、分选极好,普遍具有标准的碟形、新月形撞击坑和毛玻璃化表面,是典型的沙漠砂沉积。     

云南西北部丽江—剑川地区古近纪宝相寺组 石英砂颗粒表面特征

石英砂具有丰富的颗粒表面特征,是判别沉积环境的重要标志。利用扫描电镜对云南丽江—剑川地区宝相寺组(E2b)的石英砂颗粒表面特征进行了系统分析:下部样品具水成特征,中部样品具风成特征,上部样品则具经水流改造后的风成特征。结合野外观察结果,从宝相寺组石英砂颗粒表面特征的变化规律可以看出,下部为近源洪积环境、中部为风成沙丘环境、上部为湖泊环境。其中中部样品的石英砂磨圆、分选极好,普遍具有标准的碟形、新月形撞击坑和毛玻璃化表面,是典型的沙漠砂沉积。     

加速溶剂萃取-气相色谱法测定谷物中有机氯农药和多氯联苯

针对大米、小麦、玉米和黄豆等谷物样品中有机氯农药(OCPs)和多氯联苯(PCBs)检测的前处理过程较为复杂,消耗溶剂多,易导致部分挥发性化合物损失而影响分析的准确度,本文优化了加速溶剂萃取(ASE)提取大米、小麦、玉米和黄豆等谷物样品中OCPs和PCBs的条件,比较了凝胶渗透色谱(GPC)和固相萃取柱(SPE)两种净化方式净化样品的效果,采用气相色谱-电子捕获检测器实现了样品中17种OCPs和8种PCBs单体的系统分析.结果表明,选择二氯甲烷-丙酮混合溶剂(体积比1∶1),采用ASE萃取,同时加入弗罗里硅土在线净化,可满足样品提取需求;除了黄豆和黑豆等豆制品样品需采用GPC结合SPE的净化方法外,大米、小麦、玉米等大部分谷物样品采用SPE净化即可满足测定需求.采用弗罗里硅土SPE净化,仅用9 mL正己烷-乙酸乙酯淋洗液(体积比1∶1)即可将所有目标物回收,克服了有机试剂用量大、同时使用多种试剂及试剂毒性大的问题.添加低、高两个浓度水平0.69 μg/kg和5.52μg/kg,OCPs和PCBs单体的平均回收率为71.0％ ～ 112.0％,相对标准偏差为3.6％～16.7％(n=7);方法检出限为0.07 ～0.30μg/kg,低于国家标准方法的检出限.该方法净化效率高,操作简单,分析成本较低,适用于大批量谷物样品中多种OCPs和PCBs的快速分析.     

The significance of stretching lineations in terms of progressive deformation and finite strain

Abstract

For a given increment of deformation, stretching lineations can be defined either by old grains or by new grains.

Progressive strain accumulated in a matrix causes reorientation of old grains. The velocity field acting within a grain depends on the degree of non-coaxiality of the progressive strain in the matrix, and on the competence contrast between grain and matrix (e.g. Lister & Williams, 1983). Deformed populations of old grains do not systematically track the principal directions of finite stretch; this depends on the mechanical behavior of the grains. On the other hand, these populations may be good markers of finite strain magnitude, provided that the initial distribution is known.

In contrast, the statistical shape orientation distribution of population of new grains cannot be related in a simple way to the finite strain magnitude, but their preferred orientation is considered to be the best indicator of the principal directions of finite stretch.

An example is considered from the schistes lustrés near Kenestrelle (Val Chisone, Western Alps), where the observed mineral lineation is attributed to a late E-W stretching event in the alpine orogenic history.     

天然胶结钙质土强度及微观结构研究

自20世纪80年代起,国内就开展了关于岛礁钙质土岩土工程性质的研究工作,至今已经取得了大量的研究成果,但上述研究工作均是针对松散钙质土进行的,针对岛礁上广泛分布的胶结钙质土的研究工作尚未系统开展。而国外大量工程实践表明,胶结钙质土具有完全不同于松散钙质土的工程性状。针对天然胶结钙质土的空间各向异性,从微观角度研究影响其强度的主要参数,为今后的胶结钙质土的分类研究提供理论指导。文中采用多种试验研究方法,最后建立了天然胶结钙质土的密度、胶结度、孔隙度、颗粒大小等参数与强度间的对应关系,当前的研究结果表明,天然胶结钙质土的密度及胶结度与强度间存在良好的相关性。     

The electrification of dust-lofting gust fronts (‘haboobs’) in the Sahel

Two Doppler radars and a suite of auxiliary surface observations are used to document the electrical, aerosol and aerodynamic properties of dust-lofting gust fronts near Niamey, Niger during the AMMA (African Monsoon Multidisciplinary Analysis). Electrification with dominant negative polarity is a common behavior, consistent with earlier studies on dust devils and the Harmattan wind in dry environments.     

通过碎屑低温年龄恢复西南天山古高度

目前使用低温年代学来恢复造山带古地形,主要是采用在造山带内部采样来做原地高度的恢复。本文提出用碎屑颗粒低温年代学来恢复造山带平均古高度变化率的方法,即通过山间盆地或山前堆积碎屑物大量的单颗粒年龄,获取蚀源区大面积的、区域性的平均剥露速率,进而通过均衡校正计算出蚀源区的平均古高度变化率,为造山带古地形恢复提供了新的途径。本文以西南天山为例进行尝试,通过已发表的339个碎屑颗粒裂变径迹年龄,获得西南天山的68 Ma(年龄峰期)的剥露速率为0.740.60km/Ma,平均古高度变化率为0.150.23km/Ma、0.120.19km/Ma(降低率)。显示西南天山在68 Ma以来发生了比较快速的剥露,如果不考虑构造抬升等因素,平均古高度也发生了比较快速的降低,如果按8 Ma以来计算,则正好降低了1 0001 500m。