红外测距仪观测中折射率改正公式的发展与应用

电子测距仪是以特定的大气条件进行距离测量的，这种特定的大气条件并不与外业条件完全相同。因此观测获得的距离数据必须进行改正，即将参考大气条件转变为实际大气条件。最初的公式是从紫外到近红外辐的色散理论表达公式的科学研究中得出的。本文阐述了公式的连续演化过程以及测量人员和工程师们应该采用的实用公式。     

Bacterioplanktonic abundance,productivity and petroleum hydrocarbon biodegradation in marinas and other coastal waters in North Carolina,USA

The purpose of this study was to assess the differences in the abundance and activity of the bacterioplankton at sites with varied boating activity, and to determine the response of the communities to additional petroleum pollution. Three sites, including two marinas and a site on Bogue Sound in coastal North Carolina, were selected for monthly experiments. Seasonal patterns of bacterioplanktonic abundance and diesel fuel biodegradation for each site were examined, and possible correlations with intensity of boating activities were explored. Bacterioplanktonic communities at the three sites in this study were more similar in their structure and biodegradation potential than would have been expected from previous studies. We found no differences in the abundance and biodegradation potential of theses communities at the three sites, and only a slightly elevated number of hydrocarbon degraders at one of the marinas. Patterns of biodegradation were more closely related to total bacterial abundance, rather than number of petroleum hydrocarbon degraders. There was a strong seasonal pattern in bacterial abundance and biodegradation at all three sites. The bacterioplanktonic Community at all sites responded similarly to additions of diesel fuel. Bacterial abundance and productivity were both elevated to some extent, and number of petroleum hydrocarbon degraders changed relatively little. These data indicate that marinas may not profoundly after the bacterioplankton and that coastal waters often have resident bacterial communities capable of degrading petroleum hydrocarbon pollution.     

GPR数据时间域交错网格有限差分模拟

用有限差分（ＦＤ）时间域数值方法,我们开发、试验和实施了二维介质中数字探地雷达（ＧＰＲ）波动传播的模拟。由于现有ＧＰＲ仪器的操作频率的缘故,我们考虑了ＴＥ波的一阶效应,与频率有关的衰减以说明记录响应的重要变化。交错网格技术用于使场简单化以及用四阶有限差分逼近空间导数。时间导数用二阶有限差分时间－推进系统来显示。通过结合单程波动的旁轴近似（Ａ２）和阻尼手段（海绵滤波）,我们得到了能有效吸收向内及向外     

Microscale characterization of dissolved organic matter production and uptake in marine microbial mat communities

Intertidal marine microbial mats exhibited biologically mediated uptake of low molecular weight dissolved organic matter (DOM), including D-glucose, acetate, and an L-amino acid mixture at trace concentrations. Uptake of all compounds occurred in darkness, but was frequently enhanced under natural illumination. The photosystem 2 inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) generally failed to inhibit light-stimulated DOM uptake. Occasionally, light plus DCMU-amended treatments led to uptake rates higher than light-incubated samples, possibly due to phototrophic bacteria present in subsurface anoxic layers. Uptake was similar with either 3H- or 14C-labeled substrates, indicating that recycling of labeled CO2 via photosynthetic fixation was not interfering with measurements of light-stimulated DOM uptake. Microautoradiographs showed a variety of pigmented and nonpigmented bacteria and, to a lesser extent, cyanobacteria and eucaryotic microalgae involved in light-mediated DOM uptake. Light-stimulated DOM uptake was often observed in bacteria associated with sheaths and mucilage surrounding filamentous cyanobacteria, revealing a close association of organisms taking up DOM with photoautotrophic members of the mat community. The capacity for dark- and light-mediated heterotrophy, coupled to efficient retention of fixed carbon in the mat community, may help optimize net production and accretion of mats, even in oligotrophic waters.