东北菱中氨基酸和无机元素含量分析

目的：为评价东北菱的品质并更好地开发利用东北菱这种野生资源提供科学数据。方法：采用原子吸收光谱仪、氨基酸分析仪等分析手段。结果：测定了东北菱中蛋白质、氨基酸及七种微量元素含量。结论：结果表明,东北菱中含有8种人体必需氨基酸,蛋白质在果实和果肉中含量分别为11.90%、18.92%,人体必需微量元素Fe、Zn、Mn、Ca和P含量较高。     

校准曲线的回归与化探样品中痕量金分析准确度间的关系

本文针对日立180—80偏振塞曼石墨炉原子吸收法测定化探样品中痕量金,出现低含量样品测量值为负值的情况,探讨其引起的主要原因及其解决的基本途径。     

微量元素Mo对褐煤有机质热解成烃的影响

有机-无机相互作用是沉积盆地内普遍存在且不可改变的事实。本文采用热模拟实验方法,论述了微量元素Mo对褐煤样品热解生烃产物的影响。结果发现：Mo元素的加入,增大了褐煤热解气态产物的产率,却降低了液态烃类的产率,同时,Mo元素对热解液态抽提物族组分的组成也产生了一定的影响,使产物中芳烃的产率有所减小,从而导致了饱芳比的增加。     

Geochemical signals and source contributions to heavy metal (Cd, Zn, Pb, Cu) fluxes into the Gironde Estuary via its major tributaries

Daily measurements of water discharges and suspended particulate matter (SPM) concentrations and monthly sampling for trace element analyses (Cd, Zn, Pb and Cu) were conducted from 1999 to 2002 on the Garonne, Dordogne and Isle Rivers, the three main tributaries of the Gironde Estuary, France. Dissolved and particulate Cd, Zn, Pb and Cu concentrations in the Isle River were generally higher than those in the Garonne River, despite the known historical polymetallic pollution affecting the Lot-Garonne River system. Even if the relatively high dissolved metal concentrations in the Isle River may be of importance for the local ecosystem, metal inputs into the estuarine and coastal zones are mainly controlled by fluvial transport via the Garonne River. Characteristic element concentration ratios (e.g., Zn/Pb) in SPM and stream sediments from the Dordogne and Isle Rivers suggest two different metal source areas with distinct geochemical signals. Low Zn/Pb ratios (<8) and low Cu/Pb ratios (<0.8) have been attributed to upstream source zones in the Massif Central, featuring various ore deposits and mining areas. High Zn/Pb ratios were assigned to downstream sources (e.g., vineyards), partly explaining high Zn and Cu concentrations and high Cu/Pb ratios (>0.8) in SPM. Although SPM derived from the upstream parts of the studied watersheds may greatly contribute to the observed fluvial metal transport (up to approximately 80% for Pb), the results suggest that intensive agriculture also considerably influences gross metal (e.g., Zn, Cu) fluxes into the Gironde Estuary. Relative contributions of upstream and downstream source zones may vary from one year to another reflecting hydrological variations and/or reservoir management. Monitoring fluxes and identifying distinct geochemical signals from source areas in heterogeneous watersheds may greatly improve understanding of contaminant transport to the coast.     

Groundwater contributions to metal transport in a small river affected by mining and smelting waste

The Riou Mort watershed, strongly affected by former coal mining and Zn ore treatment, has been the major source of the historical polymetallic pollution of the Lot-Garonne-Gironde fluvial-estuarine system. Two decades after the end of ore treatment, the former industrial area still contributes important amounts of metals/metalloids from various, partly unidentified, sources to the downstream river system. This study presents the high spatial variability of metal/metalloid (Cd, Zn, As, Sb, U, V) concentrations in water and suspended particulate matter (SPM) from eight observation sites during a short, intense flood event. Despite important dilution effects, the observed concentration levels at the different sites suggested additional Cd and Zn inputs, probably from polluted groundwater. This formerly unknown metal source was then localized and characterized by sampling water and SPM along two longitudinal profiles during different hydrological situations. Groundwater inputs of "truly dissolved" (<0.02 microm) Cd and Zn occurred along approximately 200 m, contributing 43% and 28% to the total annual (2004) Cd and Zn fluxes in the Riou Mort River. The estimated groundwater concentrations of Cd and Zn (2500-6700 and 83,000-170,000 microg l(-1), respectively) in the source zone were consistent with values measured in samples from the near aquifer (5400-13,000 and 200,000-400,000 microg l(-1)). The present work induced concrete remediation actions (pumping and treatment of the polluted groundwater), that are expected to strongly reduce dissolved Cd and Zn emissions into the Riou Mort River.     

Viability of a low-pressure nanofilter in treating recycled water for water reuse applications: a pilot-scale study

The purpose of this study was to investigate the potential of a low-pressure nanofiltration (NF) membrane for treating recycled water for indirect potable water reuse applications. In particular, the tradeoffs in choosing low-pressure NF over reverse osmosis (RO) were investigated including whether or not significantly lowering operating pressures/costs would result in diminished permeate water quality. A NF membrane (Dow/Filmtec NF-4040) with high permeate productivity was selected for pilot-scale testing over a period of 1200h at a water reuse facility employing conventional RO membranes for treating tertiary treated wastewater effluent prior to aquifer recharge. The novel application of an NF membrane in treating wastewater effluent for water reuse applications permitted a comprehensive screening of NF permeate water quality and allowed for the investigation of trace organic contaminant rejection on pilot scale with environmentally relevant feed water concentrations. Results from pilot-scale testing highlighted the selectivity of NF membranes in removing organic solutes present in wastewater effluents at the parts-per-trillion level. While operating pressures were by a factor of 2-3 lower than conventional RO membranes, and bulk and trace organic rejection generally exceeded 90 percent, not surprisingly, the rejection of monovalent ions such as nitrate was poor. The poor-to-moderate rejection of monovalent ions, however, resulted in lowered brine stream total dissolved solids concentration and sodium adsorption ratio as compared with the brine stream of conventional RO membranes, which may be beneficial for brine disposal strategies.     

陕西葫芦沟金矿找矿地球化学模型与找矿标志

通过对陕西葫芦沟金矿部分微量元素与烃类组分在不同中段的含量变化及在矿体周围的异常展布特征和富集规律的分析和总结,得出该矿床原生晕分带序列为:甲烷、乙烷、丙烷、Zn、As、Ag、Sb(矿前晕)→Ag、Ni、Mn、异丁烷、正丁烷、乙烯、丙烯(矿头晕)→Hg、Pb、Ag、Au(矿中晕)→Co(矿尾晕),建立了矿床地质—地球化学找矿理想异常分带模型,并总结了找矿标志,为其深部以及外围地区的找矿预测评价提供了科学依据。     

微量物证在交通肇事逃逸案中的应用

交通肇事逃逸案件数量日益增加,犯罪嫌疑人反侦查能力增强。微量物证作为交通肇事逃逸案件的突破口,为此类案件提供坚实可信的科学依据,对案件的侦破起到了至关重要的作用,也成为侦破此类案件的最佳手段和措施。结合两起案例,展示了微量物证在交通肇事逃逸案件中的重要作用。     

空间凸轮的数控加工

将曲面与曲面之间的接触原理应用在数控加工中，可解决园柱凸轮，圆锥凸轮等空间凸轮的加工问题．该方法是将凸轮展开后，通过凸轮的轴向坐标、周向坐标和转角的几何关系及其曲线方程，解算出凸轮的切向矢量，进而求出圆柱型铣刀接触点的法向矢量及其接触点的坐标．这样，即完成了凸轮转角与刀具轴向移动间的对应关系——刀具轨迹计算，实现凸轮的数控加工。     

原油中微量元素地球化学特征

利用原油中微量元素的分布，可以明显地将陆相原油和海相原油区分开，结合原油的硫含量，可以初步判断油源岩沉积环境和岩性。利用原油稀土元素配分模式可以进行油／油对比，稀土元素分特征反映原油运移效应。Ｅｕ异常反应油源岩沉积时的相对氧化－还原条件。