普兰店组植物化石新发现

普兰店组的植物化石过去虽曾有些记录,但从未正式研究。本文报导植物化石17属23种,其中有10属15种是首次发现,包括3个新种。主要有:Pseudofrenelopsis,Suturovagina intermedia,Cuprgssinocladus gracilis,Pagiophyllum(Araucarites?),Araucarites?,Onychiopsis,Otozamites等,未见银杏类,蕨类中仅有Onychiopsis。上述植物群与中国白垩纪南方型植物群的特点相同。这些化石的发现,为普兰店组的时代确定及区域地层对比增添了新的证据。同时也进一步证明在早白垩世辽东地块曾发生过长距离自南而北的运移。     

On the Formulation of Lagrangian Stochastic Models of Scalar Dispersion Within Plant Canopies

Lagrangian stochastic models, quadratic in velocity and satisfying the well-mixed condition for two-dimensional Gaussian turbulence, are used to make predictions of scalar dispersion within a model plant canopy. The non-uniqueness associated with satisfaction of the well-mixed condition is shown to be non-trivial (i.e. different models produce different predictions for scalar dispersion). The best agreement between measured and predicted mean concentrations of scalars is shown to be obtained with a small sub-class of optimal models. This sub-class of optimal models includes Thomson's model (J. Fluid Mech. 180, 529–556, 1987), the simplest model that satisfies the well-mixed condition for Gaussian turbulence, but does not include two other models identified recently as being in optimal agreement with the measured spread of tracers in a neutral boundary layer. It is therefore demonstrated that such models are not universal, i.e. applicable to a wide range of flows without readjustment of model parameters. Predictions for scalar dispersion in the model plant canopy are also obtained using the model of Flesch and Wilson (Boundary-Layer Meteorol. 61, 349–374, 1992). It is shown that, when used with a Gaussian velocity distribution or a maximum-missing-information velocity distribution, which accounts for the measured skewness and kurtosis of velocity statistics, the agreement between predictions obtained using the model of Flesch and Wilson and measurements is as good as that obtained using Thomson's model.     

Effects of coal fly ash amended soils on trace element uptake in plants

Variations in As, Ba, Bi, Cd, Co, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Th, Tl, U, W, and Zn uptake were evaluated in young, middle-aged, and mature basil, tomato, zucchini, and sunflower plants grown in soils amended with 5, 10, and 20% by weight fly ash. Elements susceptible to uptake with increasing fly ash were As and Tl, with As exceeding potentially toxic levels in basil and zucchini. Temporal variations in element uptake included (1) increasing Ba and Cd concentrations in tomato and As, Ba, Cd, and Tl in zucchini, (2) decreasing Co concentrations in tomato, zucchini, and sunflower, Ni in zucchini, and Tl in basil, and (3) increasing As and Ni concentrations in basil and Pb in zucchini and sunflower during early growth followed by decreasing concentrations at maturity. Although most of the trace elements were below reported toxic levels, the elevated concentrations of As in plant tissue suggests that fly ash treatment programs can lead to potentially toxic accumulations of As, and thus, should be carefully monitored.     

台湾北部四种软珊瑚体内十八种金属累积于共肉组织与中轴骨骼的特性

分别检测采自台湾北部和平岛沿岸海域及淡水河出海口海域的侧扁软柳珊瑚(Subergorgia suberosa)、扁刺柳珊瑚(Echinogorgia complexa)、网刺柳珊瑚(Echinogorgia reticulata)和1未定种柳珊瑚4种软珊瑚样品体内18种金属元素。比较同株珊瑚中金属累积于共内组织与中轴骨骼含量的特性．研究结果显示铜(Cu)及钒(V)于4种珊瑚中累积于中轴骨骼的量高于共内组织，Zn、Fe、Mn、Ca、Cd、Ni、Pb及Se则恰相反，Al、As、Co、Cr及Sn累积部位没有规则，Ag,Au及Ba因有ND值(未检出值)无法归纳其累积倾向，但若忽略ND值，则Ag与Ba累积于共肉组织较高，Au累积于中轴骨骼较高．此研究结果显示环境中金属倾向累积于软珊瑚共肉组织或中轴骨骼可能有一定之脉络可循．     

口虾蛄超氧化物歧化酶同工酶的组织特异性研究

以口虾蛄为材料进行研究，用聚丙烯酰胺凝胶电泳法，对其肌肉、心脏、腹鳃、肝胰腺及眼球5种组织器官进行超氧化物歧化酶(SOD)同工酶的研究分析。结果表明：不同组织中超氧化物歧化酶(SOD)的同工酶谱带存在差异，具有明显的组织特异性。眼球、腹鳃、肝胰腺和心脏中有2条酶带，肌肉中几乎不表达，心脏中SOD2和肝胰腺中SODl谱带表达最浓，而腹鳃中的酶带表达最弱。     

冬季室温铁碳内电解质下4种水生植物及其组合的净化效果

为探究冬季室温不同铁碳内电解基质下4种水生植物及其组合对人工湿地污水的净化效果,通过构建小试试验装置来探究冬季室温铁碳内电解质下菖蒲、鸢尾、金鱼藻、狐尾藻4种水生植物及菖蒲+鸢尾、金鱼藻+狐尾藻、菖蒲+鸢尾+金鱼藻+狐尾藻3种组合在不同试验时间内对污水中COD、NH_3+-N、TN、TP 4种污染物的净化效果。结果表明:冬季室温不同铁碳内电解基质下,4种植物及其组合对COD、TN、TP去除效果均较好,无显著性差异。NH3+-N净化效果较好的是菖蒲组和金鱼藻+狐尾藻组合。研究发现,铁碳内电解基质在COD、TN、TP的去除过程中发挥了主要作用。在TN去除方面,铁碳内电解质与植物的组合效果比单纯内电解质对污水的净化效果好。4种植物及其组合在NH_3+-N去除方面均发挥了重要作用,且不同处理间存在显著差异。     

Geochemistry and biogeochemistry of rare earth elements in a surface environment (soil and plant) in South China

Plants and soils derived from different kinds of parent materials in South China were collected for analyses of rare earth elements (REEs) by inductively coupled plasma-mass spectrometry (ICP-MS). The distribution patterns and transportation characteristics of REEs in the soil–plant system were studied. The results show that geochemical characteristics of REEs depend on the types of soils, soils derived from granite being the highest in REE concentration. In a soil profile, REE concentrations are higher in B and C horizons than those in A horizon, with Eu negative anomaly and Ce positive anomaly. Plants of different genera growing in the same sampling site have quite similar REE distribution pattern, but plants of the same genera growing in different soils show considerable variation in characteristics of REEs. The patterns of the different parts of plant resemble each other, but the slope of the patterns becomes different. REEs have fractionated when they were transported and migrated from soil to plant root, stem and leaf, revealing that heavy REEs are relatively less available. REEs distributions in plants are influenced by the soil they grow in and also characterized by their individual biogeochemical characteristics. Biological absorption coefficients indicate difference of REE absorption capacity of plants. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Securing forests from the scourge of chestnut blight: The biopolitics of nature and nation

Bringing a biopolitical framework to bear on historical geographies of nature, this article traces the recent history of the American chestnut, with a focus on the pivotal time period in the early 20th century (1905–1925) during which the tree’s ecological, economic, and cultural roles changed dramatically. Once an ecologically dominant and culturally important forest tree in eastern North America, the American chestnut was rendered functionally extinct following the accidental introduction of a fungal pathogen, known as the chestnut blight, at the turn of the 20th century. Calling attention to the historical ties between nature and nation, I demonstrate how blight control, chestnut breeding, and restoration efforts were formulated in conversation with broader anxieties about the fate of the American nation in the wake of social, environmental, economic, and racial change. Through an exploration of three themes distilled from archival research—chestnut blight as national threat, fear and desire for exotic nature, and the shared histories of plant breeding and racial improvement—this paper illustrates the role that nature has played in the construction and circulation of biopolitical discourses, nationalist sensibilities, and gendered and racial logics.     

红砂正常和脱水组织中总RNA提取的改进CTAB法

红砂属于柽柳科超旱生小灌木,是荒漠半荒漠地区植被中的优势种。为了研究促分裂原激活的蛋白激酶(MAPK)信号传导通路在这类植物抗旱中的作用,我们尝试了很多RNA提取的方法都没有获得完整的RNA。在脱水组织中由于多糖、多酚以及其他与核酸能结合或共沉淀的化合物的含量升高而更不容易得到高质量的RNA。以CTAB为基础的改进的RNA提取方法,能成功地从少量的红砂植物的正常组织和脱水组织中获得高质量的RNA。这种方法经济且操作方便,提取的RNA纯度和完整性都很好,可用于RT-PCR反应并成功克隆了550 bp 左右的MAPK基因片段。     

甘谷驿油田采油厂延长组长6油层组储层裂缝研究

通过露头、岩芯裂缝描述及应用古地磁裂缝检测方法,长6储层裂缝主要以EW为主,次为SN向;在最大主应力方向为NE80°的应力场背景下,外力诱使东西向裂缝优先开启和连通,油井受效明显,含水上升快且易产生水淹,近南北向裂缝处于挤压闭合状况,裂缝孤立、连通性差,油井见效缓慢。