Measurement of 34S/32S Ratios of NBS 120c and BCR 32 Phosphorites Using Purge and Trap EA‐IRMS Technology

Measurements of sulfur stable isotope ratios (³⁴S/³²S) have suffered from technical difficulties in analysing low‐S materials reducing their use despite their undeniable scientific interest. The measurement of ³⁴S/³²S ratios is a powerful tool for deciphering problems such as determining the sources of environmental pollutants, to detect adulteration, tracking the evolution of the redox state of the oceans and quantifying the role of the bacterial activity in sulfide minerals genesis. We have used a high‐precision method of sulfur isotope determination using a new type of elemental analyser based on ‘purge and trap’ technology. This new technique demonstrates the high quality of ³⁴S/³²S measurements for samples with S concentrations lower than 1% m/m. International calibrated references of diverse sulfur‐bearing materials were used to calibrate two low (< 1%) S‐bearing phosphorites used as compositional reference material for future use as isotopic references: BCR 32 and NBS 120c. δ³⁴S_CDT values of, respectively, 18.2‰ (1s = 0.3; n = 23) and 18.3‰ (1s = 0.4; n = 20) are proposed for these. Calibration of both phosphorites with international reference materials led to calculation of a mean standard error close to 0.4‰. The demonstration of a capability to reliably measure S isotope ratios in low‐S phosphate minerals or rocks opens up new fields of palaeoenvironmental reconstructions.     

Influence of assimilating transports and in situ data from the Rapid-MOCHA array into the GECCO2 ocean synthesis

By assimilating information required for the estimation of the Atlantic meridional overturning circulation (AMOC) by the Rapid-MOCHA array, we investigate how transports should be constrained. For the period 2004–2011, we find that even the large adjustments in Florida Strait transport (FST) imposed by assimilating FST data do not impact the AMOC strength at 26.5° N while the AMOC away from this section changes due to the baroclinic response. Moreover, the high correlation between the FST and AMOC previously reported cannot be confirmed for this longer period. When assimilating FST and AMOC transports in conjunction, simulated transports can both be brought easily into consistency with the Rapid estimates while the representation of the hydrographic data at the mooring locations improves mainly at the eastern boundary. The dynamical constraint through the equations of motion conditions that the errors of the components are correlated and the total AMOC error is a much smaller than the sum of its components. Although Ekman and mid-ocean transports improve when AMOC is assimilated, the excellent AMOC representation relies on error compensation through adjustments of mainly the Ekman component. Assimilating the mooring data together with FST does not improve the representation of the AMOC. Density information is difficult to extract via assimilating temperature and salinity because of the strong density compensation in the subtropical gyre. Alternatively assimilating density from the mooring data directly was of limited success.     

Detection of nitrogenase in individual cells of a natural population of <Emphasis Type="Italic">trichodesmium</Emphasis> using immunocytochemical methods for fluorescent cells

The intercellular distribution of nitrogenase was detected in a natural population of Trichodesmium spp. collected from Shitaba Bay, Uwajima, Ehime Prefecture, Japan. Polyclonal antibodies raised against the Fe-protein and the MoFe-protein (α-subunit) of nitrogenase were used as probes. Visualization of the antibody binding to the nitrogenase was performed using horseradish peroxidase-conjugated secondary antibody and the chromogenic substrate, 3,3′-diaminobenzidine tetrahydrochloride, to avoid the masking effects caused by the bright autofluorescence emitted by the Trichodesmium cells. Nitrogenase proteins were detected in 66 to 81% of the trichomes. More than 77% of the cells were immunostained in individual nitrogenase-containing trichome. The data show natural populations of Trichodesmium spp. do not developed heterocyst-equivalent cells.     

真正射影像生成中遮蔽区域的补偿

经过正射纠正后的真正射影像,往往会出现建筑物遮挡造成的影像信息缺失区域。本文采用相邻影像补偿、图像修复两种方法依次对这些缺失区域进行补偿。对于因相邻影像信息不足,仍未补偿的剩余像素,在引入DBM模型的基础上,进一步提出一种基于有效像素的样本纹理合成方法,实验结果证明,该方法优于常规图像修复算法,生成了完整的真正射影像。     

地下水探测中的地球物理方法探讨

描述了地下水的类型及分布情况,分析了各种地球物理探测方法的基本原理,评价了各种探测技术的精度、特点及其适用范围,给出了与不同地下水环境相适合的探测方案。     

新型壳聚糖季铵盐衍生物的合成与表征

采用甲磺酸作为溶剂兼作氨基保护试剂,对壳聚糖上的羟基选择性酯化,再游离出氨基并对其氯乙酰化,最后进行吡啶成盐,得到新型水溶性的壳聚糖季铵盐衍生物,产物的结构通过核磁共振氢谱和红外光谱进行了表征,从而为壳聚糖季铵盐衍生物的制备提供了一种新途径。     

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Identification of five strains of antarctic bacteria producing low-temperature lipase

1 IntroductionMicroorganism is an important constituentof the antarctic, arctic and deep sea ecosystemswhich are characterized as permanent lowtemperature. To adapt and survive in this ex-treme environment, these microorganisms pro-duce many distinctive substances such as poly-unsaturated fatty acids (PUFA), low-tempera-ture enzymes and novel pigments, etc. (Thomasand Dieckmann, 2002). Low-temperature en-zymes have a property of higher specific activ-ity (Kcat) at low temperature. Owing to…     

滇中地区产汇流分析探讨

依据云南省滇中地区16个水文站共31年(1980~2010年)实测水文资料,应用二水源新安江模型进行降雨径流分析,用推理过程线法进行汇流分析,研究滇中地区产汇流参数地理变化规律,为无水文资料的中小河流开展水文计算和站网规划提供参考。研究结果表明:分析得出的参数具有一定的代表性,分析成果取得较好的效果。     

地质约束条件下的地质体智能综合方法研究

地质体综合是地质图编制工作的重中之重,因其处理涉及内容多、 业务逻辑复杂、 重复工作量大,是影响编图工作推进的主要因素.为了能够实现地质体的高效综合,文章提出了一种以地质约束条件(专家知识)为核心、 以制图综合为空间图形合并手段的新型地质体智能综合方法,设计并实现了围绕地质专家知识(如地质年代、 地层名称等)规则映射开...