Distribution and assessment of mercury (Hg) in surface sediments of Futian mangrove forest,China

Environmental Geochemistry and Health - To investigate the distribution of mercury (Hg) in Futian mangrove wetland, surface sediments from land to sea were collected, including Kandelia obovata,...     

Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China

Concentrations of eight trace metals (TMs) in road dust (RD) (particles?<?25 μm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg^?1, respectively. When compared with TM levels in background soil, the samples generally display elevated TM concentrations, except for Cr and Mn, and for Cd the enrichment value was 69.6. Spatial variations indicated TMs in RD from park path would have similar sources with main roads, collector streets and bypasses. Average daily exposure doses of the studied TMs were about three orders of magnitude higher for hand-to-mouth ingestion than dermal contact, and the exposure doses for children were 9.33 times higher than that for adults. The decreasing trend of calculated hazard indexes (HI) for the eight elements was As?>?Pb?>?Cr?>?Mn?>?Cd?>?Zn?>?Ni?>?Cu for both children and adults.     

蚯蚓对垃圾与底泥中镉的富集现象

通过蚯蚓处理垃圾及纳污河流底泥实验研究发现蚯蚓可选择吸收并富集垃圾及底泥中的镉，但对其他重金属元素铅、铜、锌等并无此种富集吸收现象。     

农村经济活动对云南野生稻居群的影响

云南野生稻包括普通野生稻(O.rufipogon Griff)、疣粒野生稻(O.meyeriana Baill)和药用野生稻(O.officinalis Wall),是属于全国仅存的几处宝贵基因资源库之一。野生稻具有许多优良特性及其相应的基因,在栽培稻育种和生物技术利用等方面具有巨大的潜力。文章在对云南野生稻居群长期调查或考察的基础上,分析了云南野生稻居群濒危的现状,认为热区经济开发、游牧、木材消耗、采集草药、外来种入侵和环境污染等农村经济活动是致濒的主要因素。阐明了选择合理的保护方法、加大普法和执法力度、完善保护体制与运行机制、调整种植结构是当前云南野生稻居群保护管理与经济协调发展的四项重点措施。     

云南籼稻核心种质回交后代苗期耐冷性研究

早春低温和连续阴雨是导致籼稻烂秧的主要因素之一,筛选耐冷的种质资源,将耐冷性基因导入高产的籼稻品种之中是防止低温冷害最为经济有效的方法。加强籼籼稻杂交后代的苗期耐冷性研究,可为籼稻耐冷性育种提供条件。以235份云南籼稻核心种质和云南主栽籼稻品种滇屯502(Oryzasatica)配制的杂种F5、BC1F4、BC2F3和BC3F2代为材料,在昆明自然条件下,对亲本及其后代进行苗期(三叶)耐冷性研究。结果表明,(1)不同回交世代与杂种与亲本间的苗期耐冷强弱差异较大,总体趋势为回交供体亲本>F5>BC1F4>BC2F3>BC3F2;揭示了随着回交世代的增加,其回交杂种苗期耐冷性减弱,越来越趋于轮回亲本,在耐冷育种上对回交供体亲本及其早世代材料进行选择更易获得苗期强耐冷材料。(2)同一稻作区,回交供体亲本的苗期耐冷强于杂种后代;稻作区划间,回交供体亲本及杂种F5总趋势相近,滇中一季籼稻粳稻区和滇东北高原粳稻区材料耐冷最强,而BC1F4、BC2F3和BC3F23个回交世代存在一定差异。     

河流水环境质量评价研究——对评价系统、评价方法的新探讨

本文旨在对河流水环境资源中水质、水量二要素的评价以及对定量、定性数据的综合评价进行方法论上的探讨。文中提出了模糊数学评价的改进方法,建立了一套水量评价标准和评价方法;建立了“优势度”概念并提出了水质、水量多目标定量、定性数据综合评价方法。以四川省沱江为例,对上述方法进行验证,根据评价结果划分河段,并对各河段的水资源合理利用及水环境规划提出建议。     

Propylene glycol vapor contamination in controlled environment growth chambers: toxicity to corn and soybean plants

A major, often unrecognized variable regulating plant growth in semi-closed environment is air contaminant. The vapor of propylene glycol (PG), which was used as coolant in growth chambers, has been found to be toxic to corn (Zea mays L.) and soybean (Glycine max L.) plants. PG solution leaked from a valve packing system and volatilized to vapor, which was trapped in a semi-closed growth chamber. Symptoms of leaf edge chlorosis, later developing into necrosis, were observed on the third day of emergence or on the third day after moving healthy plants into the chamber. For young soybean plants, symptoms were slightly different from those observed in corn plants; the chlorosis symptoms were not uniformly distributed on all leaves. Some soybean leaves curled up and others had white spots. This problem was identified by using a portable photoionization detector to obtain instantaneous readings of total volatile organic compound concentrations inside the chambers. The presence of PG in selected chambers was verified using sample collection with solid phase microextraction (SPME) followed by analysis with multi-dimensional gas chromatography mass spectrometry (MD-GC-MS). This information is pertinent to researchers who use controlled environment to grow plants.     

荧光化学传感器的制备及其在环境分析监测中的应用

随着荧光分析技术和传感技术的发展,荧光化学传感器已经成为一种重要的连续分析测量装置.它具有很高的选择性和灵敏度,可以实现对pH、溶解氧、含氮化合物、有毒害重金属离子、有机污染物进行实时和在线测定,因此在环境分析监测方面具有广泛的应用前景.简要介绍了荧光化学传感器的原理、制备及分类,综述了近年来荧光化学传感器的发展及其在环境分析监测中的最新研究成果,并探讨了荧光化学传感器在环境分析监测领域的应用前景和发展方向.