生活饮用水水质处理进展

综述了生活饮用水水质处理技术如饮用水水质标准、水源水水质处理标准、饮用水出厂水质处理、管网水质研究、末梢水质净化研究的进展,并指出今后应加强的改进建议。     

甘蔗糖蜜成分分析及黄血盐预处理对比分析

采用先进技术手段对湛江地区糖蜜原料进行较为详细的综合分析,测得了糖蜜中蔗糖、转化糖、灰分、总氮、水分等的含量。又从黄血盐预处理结果的对比分析中,对糖蜜中的多种常量、微量元素的含量进行测定。证明黄血盐对不同阳离子的沉淀作用是有差别的,不同类型的微生物发酵需要采取不同的预处理方法。     

环境样品中痕量多氯联苯的前处理方法及萃取材料的研究进展

多氯联苯(PCBs)是环境中一类强致癌性持久性有机污染物,而其在环境中含量极低(10-9～10-8mg/kg级),选择合适的前处理方法,以实现对环境复杂背景中痕量PCBs的分离富集,这对于PCBs的环境毒理学研究具有重要意义。使用绿色环保的前处理技术,减少有机试剂用量,并能简化实验步骤,提高富集和分离效率,且最大程度上减少背景干扰是当前PCBs前处理方法发展的方向。近年来PCBs的前处理方法取得了较快发展,开发新型的萃取材料是发展高效快捷前处理方法的关键因素。文章综述了国内外PCBs的前处理方法,包括液液萃取、超临界流体萃取、微波萃取、加速溶剂萃取、固相萃取。固相萃取已经成为富集PCBs的最佳提取方法之一,固相萃取方法使用的材料(键合硅胶、有机物聚合树脂、活性炭、纳米材料、分子印迹材料)对PCBs富集原理和富集效率、操作过程等各有优缺点。新型的磁性固相纳米萃取材料由于其极高的比表面积和强吸附性能,较常规的固相萃取方法大大缩短了前处理时间;分子印迹萃取纳米材料对PCBs兼具高富集性和高选择性的突出优点,可以大大降低背景干扰,非常适合于痕量PCBs的无干扰萃取。这两种材料是今后主要的发展方向。     

生物样品中硒形态分析前处理技术

样品前处理过程在硒形态分析中至关重要。文章对生物样品中硒形态分析的前处理方法,包括液相萃取、微波辅助萃取、固相微萃取、液相微萃取等及其应用进行归纳总结,指出了痕量、超痕量硒形态分析前处理技术的未来发展方向主要集中在满足简单、快速和环境友好的自动化处理,并着重于样品前处理的各种萃取技术在线耦合以及与硒形态分析检测器联用技术。     

不同前处理方法对南方红土粒度测量的影响——以安徽宣城第四纪红土剖面为例

以安徽宣城官塘村第四纪红土剖面为例,研究了不同前处理方法对南方红土粒度测量的影响。结果表明:(1)南方红土中所含的有机质对粒度测量结果会产生明显影响,在进行粒度测量前处理时,必须加入双氧水去除有机质;(2)南方红土因淋溶强烈,碳酸钙含量极低,对粒度测量结果无影响,无需加入盐酸进行去钙处理。加入盐酸反而使得所测粒径偏粗;(3)与六偏磷酸钠相比,氢氧化钠作为分散剂因其强碱性产生的复杂化学反应,会导致所测得的粒度频率曲线峰态出现异常,且<1μm的黏粒组分含量减少,故不宜用作南方红土粒度测量的分散剂;(4)在对南方红土进行粒度测量时,建议使用H2O2+(NaPO3)6的前处理方法,即先使用双氧水去除有机质,再使用六偏磷酸钠作为分散剂,并用超声波清洗仪震荡后上机测试。     

Study on antithrombotic and antiplatelet activities of low molecular weight fucoidan from Laminaria japonica

The antithrombotic and antiplatelet effects of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica were compared in order to examine the influence of chemical character on their antithrombotic activity and the possible mechanism. Both LMW fucoidan fractions exhibited favorable antithrombotic activity in an Fecl3-induced arterial thrombosis. The antithrombotic activity of LMW fucoidan was related with decrease of TXB2 and whole blood viscosity and hematocrit. LMW fucoidan showed a correlation between anticoagulant, antiaggregant and antithrombotic effects in vivo. For LMW fucoidan, antithrombotic activity required high dose of 5-10 nmol kg-1, concomitantly with increase in anticoagulant activity and inhibition of platelet aggregation. Administration of LMW fucoidan significantly promoted the 6-keto-PGF1α content and decreased the TXB2 content, indicating its inhibition of tissue factor pathway and regulation of metabolism of arachidonic acid. By comparison, highly sulfated fucoidan LF2 with Mw 3900 seemed to be a more suitable choice for antithrombotic drug for its antithrombotic activity accompanied with specific inhibitory activity on platelet aggregation, low anticoagulant activity and low hemorrhagic risk in vivo.     

海底浮岩前处理方法的实验研究

为了解海底浮岩气孔充填物对全岩微量元素组成的影响,并获得有效的海底浮岩前处理方法,对冲绳海槽中部的浮岩碎成大于5 cm,1~2 cm及小于5 mm的碎块分别进行前处理,然后通过扫描电镜(SEM)和X射线衍射光谱(XRD)分析对清洗的效果进行观察对比。结果表明,对大块浮岩直接清洗以及将浮岩碎成厘米级小块后清洗都难以将浮岩气孔内充填的细粒沉积物去除干净,而对浮岩碎成毫米级(5 mm)颗粒后再清洗可以有效清除浮岩气孔内的充填物。本文所确定的一套有效的海底浮岩前处理方法总结如下:(1)将小于5 mm的浮岩颗粒置于超声波清洗机内用蒸馏水清洗,每隔15 min换一次水,直到清洗样品后的水足够清澈;(2)将样品先后浸入无水乙醇和稀盐酸溶液中,分别去除有机质和次生碳酸盐、铁氧化物;(3)将浮岩样品置于40℃超纯水中浸泡7 d左右,并每天换水,直至向上层清液加硝酸银溶液无白色沉淀出现。XRD分析表明,海底浮岩气孔中充填物的矿物组成包括斜长石、石英等。少量的气孔充填物对浮岩全岩的微量元素配分模式影响不大,但会造成Pb、Sr等元素含量的增加,因此可能会对浮岩全岩的Pb-Sr同位素组成造成干扰。     

FHD质子磁力仪数据预处理及月报编制软件

针对FHD质子磁力仪日常数据处理工作实际,开发了"FHD质子磁力仪数据预处理及月报编制软件",该软件具有很强的针对性和实用性,能够方便快捷的对FHD质子磁力仪仪器产出数据进行常规预处理,产出丰富的数据产品,并能够进行月报表的制作等,明显提高了数据资料可用性和台站日常数据处理的效率。     

Reliable radiocarbon dating of fossil pollen grains: It is truly possible

Radiocarbon dating of fossil pollen concentrates has the potential to reduce limitations for sample selection in chronological studies of sedimentary archives. The recent development of the technology for rapidly preparing highly purified fossil pollen concentrates using a cell sorter makes it realistic to turn this dream into reality. Before utilizing pollen as a material for dating with confidence, however, it is necessary to understand the factors that may affect the result of the measurements, and to establish criteria to assess the reliability of the radiocarbon ages produced. In this study, peat soils which are commercially available in large quantities, and are hence used as our laboratory standard, as well as the varved lacustrine sediments from Lake Suigetsu, which has one of the best terrestrial radiocarbon stratigraphies in the world, were used to assess the accuracy of radiocarbon ages of pollen concentrates and to establish an appropriate protocol for sample preparation. A pollen-rich fraction prepared by a recently proposed combined method of physio-chemical pre-treatment and cell sorter (Yamada et al. 2021) was submitted to a range of different posterior treatments and radiocarbon measurement. The results were also compared with SEM (Scanning Electron Microscoic) and Fourier Transform Infrared Spectroscopic observations. It was discovered that the sample prepared by the initial pre-treatment and cell sorter were not sufficiently pure and did not yield radiocarbon ages that were consistent with the terrestrial leaf fossils. Instead, the Acid-Base-Acid treatment with ultrafiltration following on from the cell sorter step proved to be highly effective in the removal of contaminants and improve the measured ages. The comparison with Suigetsu's terrestrial radiocarbon dataset also indicated that accuracy could be improved through closer assessment using the pollen taxa composition, carbon content (%C), and stable isotope ratios (δ¹³C) of the pollen concentrates. The age-depth models established by the radiocarbon dating of fossil pollen grains extracted from the Suigetsu sediments agree very well with that of plant macrofossils, and even improve the precision of the combined model. As long as handling was appropriate, the pollen concentrates prepared by the cell sorter provide reliable radiocarbon ages and the method can significantly contribute to Quaternary sciences in the future.     

西藏高原夏季降水对ENSO的响应

通过合成分析指出包括雅藏布江中西段在内的西藏高原中西部地区夏季（6－8月）降水在ENSO的不同位相期间存在着显著的差异。利用交叉谱和奇异值分解等方法，分析了高原夏季降水场与太平洋海温场在时间和空间上的联系，结果表明，ENSO的暖（冷）位相期，高原大部分地区夏季降水以偏少（多）为主。