Avoidance of crude-oil contaminated sediment by the Australian seastar, Patiriella exigua (Echinodermata: Asteroidea)

This study attempted to determine whether Patiriella exigua, an Australian seastar, could detect and/or avoid oiled sediment when given an equal choice of unoiled sediment. The sediment was spiked once to produce one of three concentrations of oiled sediment used in the test chambers versus unoiled sediment. Behavioral observations were repeated over a 32 day period to test the effects of aging the oiled sediment. Results show that Patiriella exigua was capable of detecting oiled sediment and/or an oiled environment. Seastars avoided oiled sediment, with significantly higher numbers choosing either to reside on the clean sediment (p<0.05) or to travel up the glass sides of the tanks (p<0.001). Avoidance of oiled sediment increased with increasing sediment oil concentrations. Aging the oiled sediment decreased the oil content of the sediment and increased the number of seastars able to inhabit it (p<0.001). A potential narcotic effect of exposure to oiled sediment was observed.     

Space-time visualization and analysis in the Cancer Atlas Viewer

This article describes the Cancer Atlas Viewer: free, downloadable software for the exploration of United States cancer mortality data. We demonstrate the software by exploring spatio-temporal patterns in colon cancer mortality rates for African-American and white females and males in the southeastern United States over the period 1970–1995. We compare the results of two cluster statistics: the local Moran and the local G*, through time. Overall, the two statistics reach similar conclusions for most locations. Where they disagree reveals functional differences in the kinds of local spatial variation to which the statistics are sensitive and identifies some interesting patterns in the data. There are only two persistent clusters of colon cancer mortality through time, and these are clusters of low values.This project was funded by grant CA92669 from the National Cancer Institute to BioMedware, Inc. The perspectives stated in this article are those of the authors and do not necessarily represent the official views of the National Cancer Institute. Constructive criticism from Heidi Durbeck of BioMedware, Peter Rogerson of SUNY-Buffalo, and three anonymous reviewers helped us improve the interpretation and presentation of these results.     

利用矿物成分概率神经网络法进行矿床分类

为了进一步确定量化矿床模式是否令人满意，本文对利用矿物成分概率神经网络法进行矿床分类做了检验。典型类型矿床的矿石和蚀变矿物成分存在与否被用来训练神经网络。为了降低要考虑的矿物种类，只利用至少一类矿床中矿物区占２０％以上的那些矿物。这一限制的好处在于单个或很少出现的矿物不会影响到正确分类结果。概率神经网络在贝叶斯定理基础上能定量地提供令人信服的分类度量，并且相对地对异常值不敏感。以Ｐａｒｚｅｎ密度估     

亚马逊水下三角洲底部边界层的测量

亚马逊水下三角洲底部边界层的测量Ｄ．Ａ．Ｃａｃｃｈｉｏｎｅ等近底边界层为流体剪切为直接作用于悬浮物及底床表层沉积物以形成冲刷或沉积的地带．对水下三角洲生长及结构的动力过程的认识主要借助于分析近底边界层重要的物理及沉积参数来进行的．本文我们利用ＧＥＯＰ...     

Prediction of the thermodynamic properties of aqueous metal complexes to 1000 degrees C and 5 kb

A large number of aqueous metal complexes contribute significantly to hydrothermal, metamorphic, and magmatic processes in the crust of the Earth. Nevertheless, relatively few thermodynamic data other than dissociation constants (K) for a few dozen of these complexes have been determined experimentally at elevated temperatures and pressures. The calculations summarized below are intended to supplement these experimental data by providing interim predictions of the thermodynamic properties of supercritical aqueous metal complexes using the revised HKF (Helgeson et al., 1981) equations of state for aqueous species (Tanger and Helgeson, 1988; Shock et al., 1992) and correlations among equations of state parameters and standard partial molal properties at 25 degrees C and 1 bar (Shock and Helgeson, 1988, 1990; Shock et al., 1989). These equations and correlations permit retrieval of the conventional standard partial molal entropies (mean S0), volumes (mean V0), and heat capacities (mean C0P) of aqueous metal complexes at 25 degrees C and 1 bar from published values of log K in the supercritical region and the limited number of experimental dissociation constants available in the literature over relatively short ranges of elevated temperature at PSAT (PSAT and SAT are used in the present communication to refer to pressures corresponding to liquid-vapor equilibrium for the system H2O except at temperatures <100 degrees C, where they refer to the reference pressure of 1 bar). The standard partial molal properties computed in this way can then be used to generate corresponding values of delta mean S0, delta mean V0, and delta mean C0P of association, which for similar complexes correlate linearly with mean S0, mean V0 and mean C0P, respectively, of the constituent cations and ligands at 25 degrees C and 1 bar. Generalizing these correlations and combining them with the equations of state permits prediction of the temperature and pressure dependence of log K and other thermodynamic properties of a large number of aqueous metal complexes. As a consequence, it is possible to retrieve values of log K at 25 degrees C and 1 bar from the results of hydrothermal experiments at higher temperatures and pressures or to predict values of log K at hydrothermal conditions when no experimental data are available at temperatures and pressures above 25 degrees C and 1 bar. Such predictions can be made for temperatures and pressures from 0 degrees C and 1 bar to 1000 degrees C and 5000 bars.     

1993年矿物岩石地球化学青年学者学术讨论会暨第二届全国矿物岩石地球化学青年科学家及研究生学术讨论会纪要

由中国科学院和国家自然科学基金委员会、中国矿物岩石地球化学学会主办,中国科学院地球化学研究所承办的“1993年矿物岩石地球化学青年学者学术讨论会(暨第二届全国矿物岩石地球化学青年科学家及研究生学术讨论会)”,于1993年7月26～29日在贵阳举行。会议收到论文摘要198篇,并于会前由地震出版社出版了名为《矿物岩石地球化学新探索》的论文摘要集。出席本次会议的代表共120人,其中国内青年代表82人,回国留学人员和外籍学者13人,特邀代表25人。大