作为热机的自然对流∶CAPE理论

在许多行星上，不断有热量供给地面，且热量也不断通过大气向太空发出红外辐射。由于在高压区是热源不是热汇，因此，该系统能够做机械功。大气对流是可以在此系统中运转的自然浮力、垂直速度及其覆盖区域。在对流热机一次循环期间，来自地面层（热源，热区）的热，其中一部分被报废到空间自由对流层（热汇，冷区），并从那里辐射到太空，其余部分变为机械功。此机械功用于克服机械耗散维持对流运动上。最终，机械能耗尽，转变成热能     

地气相互作用的自适应多级模拟

自适应多级模拟（ＡＭＭ）方法能将大气模式和陆面水文模式安全耦合，并保持其大尺度（大气）分量和区域（陆地）分量间的一致性，用这个方法研究了三个个例。     

GPS在机场定位测量中的应用及数据处理

本文介绍了将ＧＰＳ用于机场定位测量的全过程，包括ＧＰＳ网的布设，外业观测和数据处理，着重讨论了ＧＰＳ网络束平差中固定基准选取的有关问题，对不同约束条件的平差方案进行了说细的分析和比较，最后得出最优结果。     

Kinetics of vitellogenin protein and mRNA induction and depuration in fish following laboratory and environmental exposure to oestrogens

Plaice, flounder and sand goby were exposed to ethynylestradiol (EE2) for 21 days and then followed for up to 31 days after removal of the oestrogen. Plasma vitellogenin (VTG) and hepatic VTG mRNA were determined in groups of fish sampled during the induction and post-exposure phases. VTG mRNA increased slightly earlier than plasma protein, but both reached maxima by 21 days. In contrast, VTG mRNA decayed much more rapidly than protein after EE2 exposure was terminated (typical values t(1/2) mRNA 3 days, protein 15-30 days). Vitellogenin and VTG mRNA thus measure different temporal events and this is illustrated by field data of male flounder in which both parameters have been determined. Few fish show co-ordinate increased VTG mRNA and vitellogenin but rather more fish have increased vitellogenin. Low level increases of VTG mRNA (5 X) is observed in some fish without increased vitellogenin and this may represent polymorphic differences between individual fish.     

CSAMT法接收系统中电磁耦合效应研究

针对可控源音频大地电磁法(CSAMT)野外数据采集中接收电缆线之间、接收电缆线和大地之间存在的电磁耦合效应,通过电磁耦合理论研究和等效电路计算,推导正演模拟计算公式,结合各种模型的正演模拟计算和野外实际数据对比,研究了可控源音频大地法中影响电磁耦合效应的三种因素,包括:电缆线长度、不极化电极接地电阻、信号频率,总结出三种因素对应的电磁耦合特征,即:接收系统中电缆线长度越长,电缆线之间的耦合电容越大,视电阻率曲线在高频段出现下降的趋势越明显,曲线畸变越明显;野外不极化电极上接地电阻越大,视电阻率曲线在高频段表现出下降的趋势越明显,曲线畸变越明显;电路中信号频率越高,感抗和容抗越大,曲线畸变越明显,当信号频率增大到一定的值时,电路中的感应容抗就不再继续增大,曲线趋于稳定。     

Inorganic and methylmercury: do they transfer along a tropical coastal food web?

Methylmercury (MeHg) and inorganic mercury (Hg_inorg) were evaluated in the water of a Brazilian estuary, with two size classes of plankton and seven fish species of different feeding habits. Water partition coefficients (PCs) in microplankton were fourfold higher for MeHg than for Hg_inorg; and water PCs in mesoplankton were 26 times higher for MeHg than Hg_inorg. Difference between microplankton and mesoplankton MeHg bioaccumulation factor (BAF) was higher (0.60 log units) than Hg_inorg BAF (0.24 log units), indicating that trophic transfer of MeHg between planktonic organisms is more efficient than Hg_inorg transference. MeHg concentrations, proportion of mercury as MeHg and its biotransference factors (BTFs) in the microplankton, mesoplankton and fish increased with increasing trophic level while biotic concentrations of Hg_inorg and proportion of mercury as Hg_inorg decreased thus indicating that MeHg was indeed the biomagnified species of mercury. MeHg reflected the vertical trophic guilds distribution, due to the fact that the top predator fish presented the highest concentration (0.77 μg g⁻¹ d.w.), followed by the less voracious species (0.43 μg g⁻¹ d.w.); while planktivorous fish presented the lowest concentrations (0.044 μg g⁻¹ d.w.). Hg_inorg did not present the same behavior. Results suggest that feeding habits and trophic guild are important parameters, influencing biotransference and biomagnification processes.     

Comparative effects of herbicides on photosynthesis and growth of tropical estuarine microalgae

Pulse amplitude modulation (PAM) fluorometry is ideally suited to measure the sub-lethal impacts of photosystem II (PSII)-inhibiting herbicides on microalgae, but key relationships between effective quantum yield [Y(II)] and the traditional endpoints growth rate (mu) and biomass increase are unknown. The effects of three PSII-inhibiting herbicides; diuron, hexazinone and atrazine, were examined on two tropical benthic microalgae; Navicula sp. (Heterokontophyta) and Nephroselmis pyriformis (Chlorophyta). The relationships between Y(II), mu and biomass increase were consistent (r(2)0.90) and linear (1:1), validating the utility of PAM fluorometry as a rapid and reliable technique to measure sub-lethal toxicity thresholds of PSII-inhibiting herbicides in these microalgae. The order of toxicity (EC(50) range) was: diuron (16-33nM)>hexazinone (25-110nM)>atrazine (130-620nm) for both algal species. Growth rate and photosynthesis were affected at diuron concentrations that have been detected in coastal areas of the Great Barrier Reef.     

Variability of metal contents in the sea rush Juncus maritimus-estuarine sediment system through one year of plant's life

Metal accumulation by Juncus maritimus and the effect this plant might have on the physico-chemical composition of sediments, from Douro river estuary (NW Portugal), were investigated through one year of plant's life. The contents of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined (by atomic absorption spectrophotometry) in sediments, rhizosediments (those among plant roots and rhizomes) and different tissues of J. maritimus. Two estuarine sites with different characteristics were studied, one a sandy sediment with relatively low organic matter content, the other a muddy site. The role of the plant seemed to be markedly dependent on the sediment composition. At the sandy site, significant variations throughout the year (a decrease from winter to summer and an increase in autumn) either in rhizosediment and sediment or in J. maritimus roots were only observed in Cd and Cu levels. These variations were the same in both compartments, probably caused by tidal water movements and the activity of the plant. At the muddy site, variations throughout the year were observed for all studied elements but Pb. Changes in the Cd and Zn contents of roots were opposite to those in the rhizosediment (uptake of Cd and Zn by J. maritimus roots in summer may have caused a decrease in rhizosediment levels). Fe and Mn showed similar patterns of variation in both roots and rhizosediment (contents significantly increasing in summer). Higher contents of Fe and Mn in roots in summer could be related to changes in mass, higher availability of the elements, or accumulation at the surface of the root in (hydr)oxides forms. For the remaining elements no significant correlations between rhizosediment and roots variations were observed, indicating that their uptake and release by roots were not based on single exchanges with the sediment. J. maritimus showed capacity to accumulate Cu, Zn and particularly Cd, thus appearing to be useful for the phytostabilization of these metals.     

Spatial and seasonal variations of the macrobenthic community and metal contamination in the Douro estuary (Portugal)

The macrobenthic community structure and characteristics of sediments were studied in samples collected seasonally at five stations in the lower mesotidal Douro estuary, Portugal. Sediment characterisation included grain size distribution, total-recoverable metals (Al, Fe, Mn, Zn, Cu, Cr, Pb, Ni and Cd), acid-volatile sulphides (AVS) and simultaneously extracted metals (SEM) and total organic matter contents. Spatial variation surpassed temporal variation both in terms of environmental parameters and community structure. Clear anthropogenic contamination in terms of Zn, Cr, Cu and Pb, and a positive SEM-AVS, indicating the potential bioavailability of these metals, were detected on the north bank of the estuary. Multivariate analysis revealed that in addition to natural sediment characteristics, the anthropogenic metal contamination was influencing the macrobenthic community structure. In fact, greater concentrations of Zn, Cr, Cu and Pb were associated with lower number of species and/or diversity. Finally, the dry weight-normalised metal concentrations appeared as a more useful tool than the SEM-AVS model in predicting disturbance of the macrobenthic community in the studied area.     

AMT近源干扰压制方法

音频大地电磁法(AMT)在野外采集的是包含了多种频率的时间序列数据,这些数据中常含有干扰信号。大量查看音频大地电磁法野外实测时间序列数据,发现测量数据受到严重的近源干扰,但干扰信号不是连续出现的。于是通过分析V5-2000大地电磁仪的原始数据格式,根据干扰信号的特征,提出一种自动筛选时间序列数据的方法。宁芜地区的实测资料处理结果表明,该方法能在一定程度上压制近源干扰。