岷江上游叠溪古堰塞湖沉积物粒度特征及环境意义

利用古堰塞湖沉积物中连续的地质记录来研究区域过去气候变化规律,这一方法是继通过深海沉积、极地与高山冰芯、黄土、湖泊、洞穴石笋、珊瑚等沉积物中的地质记录来研究全球气候变化途径之后的又一新途径。反映沉积物中环境信息的代用指标有多种,其中粒度特征就是其中一种,它可以反映沉积过程中的古环境、古气候特征。通过该项研究可以建立青藏高原东部边缘(岷江上游叠溪地区)2万年以来的古环境古气候演化规律以及地质环境的演化规律,找到气候环境变化与地质环境演化的相关性。本文采用精细粒度分析和系统粒度分析等方法提取了堰塞湖相沉积物的粒度特征资料,并与已有的冰川湖沉积物的研究成果进行了对比分析。通过精细分析得到了堰塞湖相沉积物多为粉土和黏土; 深色沉积物与粗颗粒相对应,浅色沉积物与细颗粒相对应的关系; 并结合有机质测试发现:深色沉积物有机质含量多于浅色沉积物,表明粗颗粒土代表的是雨水充沛水动力条件好且植被相对茂盛的气候环境特征,细颗粒土则与其相反; 沉积物中深浅交替的纹层厚度约为2~5cm; 这些特征与冰川湖沉积物特征差别很大,因此其代表的气候环境意义也完全不同。通过整个剖面的系统粒度分析得到了整个沉积过程的粒度变化特征,并据此结合年代测试结果将整个沉积剖面划分了7个粒度变化周期,揭示了该沉积过程中该地区经历了7次气候环境的变迁。     

Combined approach of isotope mass balance and hydrological water balance methods to constrain the sources of lake water as exemplified on the small dimictic lake Silbersee,northern Germany

Stable isotopes of hydrogen and oxygen are often used for water balance calculations of lakes. We present an approach combining the lake water balance with an isotope mass balance to constrain the sources and sinks of the water of a small dimictic lake subjected to eutrophication. Meteorological and hydraulic data in combination with measured isotope signatures of the different water compartments enabled to assess the degree of surface water/groundwater interaction and the amount of overland flow into the lake. Groundwater could be excluded as a lake water source, as its water level was always below the lake water level. In the absence of a channelled inflow, precipitation and overland flow were the remaining options, whereby the latter was only active during periods of exceptionally high rainfall. While the groundwater signatures adjacent to the lake showed an influence of lake water, the lake water balance itself indicated that the associated volumetric water loss to groundwater is rather negligible. In the present case, only a combined assessment of hydrological and isotopic data allowed for an accurate characterization of the studied lake and a quantification of its water sources and sinks, highlighting the importance of using more than one methodological approach for such a purpose.     

Low-density solvent-based dispersive liquid-liquid microextraction followed by HPLC-ICP-MS for speciation analysis of phenylarsenics in lake water

A simple and fast method of low-density solvent based dispersive liquid-liquid microextraction (LDS-DLLME) followed by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation analysis of organoarsenic and inorganic arsenic in water samples. The low-density solvent (octanol) was given as the organic phase and injected into the aqueous sample (donor phase) with methanol as the disperser. With As (V), As (III), p-APAA, 4-HPAA, ROX and PAA as target species, factors of LDS-DLLME including pH value, anionic carriers, elution conditions and extractant, were studied in detail. Besides, volumes of solvents were further optimised by response surface methodology. Under the optimal conditions, the limits of detection for four phenylarsenics and arsenate were in the range of 0.001–0.039 μg L^?1. The relative standard deviations (RSDs) were 3.6–9.4% and the enrichment factors varied from 6.2 to 70.8. The proposed method of LDS-DLLME-HPLC-ICP-MS was satisfactorily applied to the determination of six arsenic compounds in water samples with recoveries of 81.8–111.7% for the spiked lake water samples.     

Two novel yellow pigments natronochrome and chloronatronochrome from the natrono(alkali)philic sulfur-oxidizing bacterium Thialkalivibrio versutus strain ALJ 15

Two novel membrane-bound yellow pigments natronochrome (1) and chloronatronochrome (2) were isolated from the obligately chemolithoautotrophic sulfur-oxidizing natrono(alkali)philic bacterium Thialkalivibrio versutus strain ALJ 15. They were derivatives of fully unsaturated fatty acids with a phenyl group, and their structures were determined by spectral data.     

THE DURABILITY OF GLASS FIBER REINFORCED COMPOSITE REBARS IN SALT LAKE HIGH AND COLD AREA1)

对玻璃纤维(glass fiber reinforced polymer, GFRP)筋和GFRP -钢筋夹芯复合筋在盐湖地区多重环境因素耦合作用下进行耐久性试验,分析环境类型及作用时间对极限抗拉强度、弹性模量、极限应变的影响。结果表明：在多重因素耦合作用下,随着盐湖卤水腐蚀周期、冻融次数、干湿循环次数的增加,GFRP筋和GFRP夹芯复合筋的抗拉强度逐渐减小,但是GFRP筋减小的幅度较小,而GFRP夹芯复合筋由于有钢筋的存在,抗拉强度减小比较大,特别是在盐湖卤水90 d以上、冻融150次以上时GFRP夹芯复合筋的极限抗拉强度实验不是很明显,屈服强度几乎不存在并且与抗拉极限强度相接近,表现出明显的脆性;在各种因素作用下,GFRP筋随着龄期的增加,弹性模量先减少后增加,而GFRP夹芯复合筋的弹性模量逐渐减小,相对来讲减小的幅度不是很大;各种耦合因素作用下GFRP筋和GFRP夹芯复合筋的极限抗拉强度、弹性模量均比单因素作用下小,且腐蚀性的大小关系是盐湖卤水+干湿循环+冻融耦合>盐湖卤水+干湿循环>冻融>盐湖卤水。     

太湖水体中有机污染物的分析

利用超临界流体萃取与热脱附两种样品预自理方法的优势互补,与气相色谱分析相结合对太湖水体中不同沸点有机污染物进行了分析,发现太湖水中除了烃类污染物外还存在大量含氮有机污染物。其分布表明入湖河道中排放的工业污染物的流入是导致太湖水富营养化的一个重要因素。     

“西溪”和“西湖”两个风景区的比较研究

准备开发利用的西溪风景区即杭州蒋村南部的水网平原不同于西湖风景区,它由全新世中—晚期冲积—湖积作用形成的．固有的自然环境和民风俗习使它拥有一派田园水乡风光和逸致文化的氛围．“西溪”的“田园式”风光与“西湖”的“公园式”风光有很大区别,但它与“西湖”构成了杭州东西两地旅游资源优势互补的良好格局．重建西溪景区可以为21世纪追求“回归自然”的人们和钟情于“文化观光”的人们提供一个理想的去处,对广大游客有强大的吸引力,也能为促进杭州旅游业的持续发展创造有利条件．     

南四湖水中多环芳烃的分析及分布研究

采用固相萃取结合气相色谱-质谱(GC-MS)方法对南四湖水中13种多环芳烃进行了分析。南四湖水中检出的多环芳烃以二环、三环为主,检出的6种多环芳烃中相对含量较高的是菲、芴和苊,多环芳烃总浓度范围为0.004~3.53μg/L。入湖河口各点浓度比湖内点位低,上级湖的入湖河口含量高于下级湖的入湖河口,且湖内各点位多环芳烃的含量按湖水流向逐渐降低。     

黄河上游戈龙布滑坡高速下滑成因机制及堵江分析

黄河上游戈龙布滑坡位于积石峡水电站库区内,经过现场调查可知,戈龙布滑坡为一大型滑坡,整个滑坡体积达到5040万m3,一共分为4个区。研究表明,戈龙布滑坡成因机制为滑移－拉裂型,滑坡在黄河右岸经过高速远程下滑过后撞击上游山体,部分滑体越过黄河堆积于左岸并堵塞黄河达数百年,堰塞湖内有厚度达30余米的纹泥沉积,初步分析滑坡坝的高度在100m左右,库水深在70m左右,滑坡堵江时代在Q4时期。滑坡坝溃决后导致黄河改道,残留的滑体分别位移黄河的左岸和右岸。     

盐湖卤水硼同位素测定中硼的二次离子交换分离

根据盐湖卤水水化学特点,介绍了一种用阳、阴离子交换树脂,动态和静态交换相结合,对盐湖卤水中的硼进行分离纯化的简易方法。用该方法从盐湖卤水中分离出来的硼足以满足同位素质谱分析的需要,分离过程不产生同位素分馏,获得了理想的实验结果。