Palaeoclihlatic Indicators of China's Quaternary Saline Lake Sediments and Hydrochemistry

In this paper the authors classify saline lake sediments into the cold, warm and eurythermal phases, reveal the consistency between the zoning of hydrochemical types of modern saline lake water and climatic zoning and give climatic parameters under the conditions of typical cold phase (mirabilite and natron), warm phase (thenar-dite) and slightly warm phase (bloedite) saline lake deposition.     

微生物絮凝剂絮凝活性研究

用微生物絮凝剂对2g/L,200目高岭土悬浊液絮凝率的测定,得出培养液中絮凝活性分布及活性菌产生絮凝剂时的最佳条件.这种菌产絮凝剂的最佳条件如下pH值7.5～9.0,温度28～30℃,300r/min摇床培养45～60h.     

表面活性剂强化空气扰动修复氯苯污染含水层

通过一维砂柱实验研究了阴离子表面活性剂十二烷基苯磺酸钠(SDBS)对空气扰动技术(air sparging,AS)修复氯苯污染地下水的强化效果.结果表明,SDBS的加入降低了地下水的表面张力,减小了水气两相毛细压力,从而提高了地下水中的空气饱和度.当曝气量为100 mL/min,地下水的表面张力由72.2 mN/m降至49.5 mN/m时,地下水中空气饱和度由13.2%提高至50.1%,而后随着表面张力的进一步降低,空气饱和度不再提高,反而有小幅下降.通过污染物的去除实验发现,SDBS的加入大大提高了氯苯的去除率,且去除率的变化与空气饱和度的变化趋势基本相符.因此,表面活性剂的加入可以作为空气扰动技术一种十分有效的强化手段.      

Geochemistry evidence for depositional settings and provenance of Jurassic argillaceous rocks of Jiyuan Basin,North China

This paper aims to discuss the depositional settings and provenances for the Jurassic in Jiyuan basin, North China, based on the rare earth element (REE) and trace element features of 16 Jurassic argillaceous rock samples from the Anyao, Yangshuzhuang and Ma’ao Formations, respectively. Generally, geochemical analysis results show that chondrite-normalised REE distribution patterns of all the three formations are characterised by light-REE (LREE) enrichment, moderately negative Eu anomalies, slightly negative Ce anomalies, and strong fractionation between LREE and heavy-REE (HREE). Trace element proxies V/(V + Ni), Ce _anom index, Ce/La, Sr/Ba, and Sr/Cu indicate a weak oxidation–reduction environment, progressively decreasing reducibility and water depth from the bottom up during Jurassic in Jiyuan basin. Palaeoclimate varied from humid in the Early Jurassic to arid in the Middle Jurassic, corresponding with the variations of palaeoredox and palaeosalinity. The provenances of Jurassic rocks in Jiyuan basin are mainly from felsic sources related to active continental margin and continental island arc. The Early–Middle Jurassic (Anyao and Yangshuzhuang Formations) provenances are mainly derived from North Qinling and partially from the eroded recycled felsic sedimentary covers of Taihang Mountain. In the late stage of Middle Jurassic (Ma’ao Formation), Taihang Mountain has been the primary source to Jiyuan basin. We conclude that the Jurassic rocks of Jiyuan basin reveal the progressive uplift and denudation processes of the Taihang Mountain.     

北祁连造山带石包城地区花岗岩年代学及成因

北祁连造山带内发育大量早古生代花岗质岩石,对其进行研究有助于加深对造山带构造演化的理解。本文以带内西段石包城地区的花岗岩为研究对象,对其进行锆石U-Pb年代学、Hf同位素以及地球化学方面的研究。结果表明:(1)该花岗岩形成时代为465~463Ma,地球化学数据表明其属于钙碱性系列,并具强过铝质特征;(2)该花岗岩T_(Zr)和T_(REE)平均温度分别为760℃和732℃,ε_(Hf)(t)变化于+7.6~+13.5,二阶段模式年龄变化于581~957Ma;(3)可能属I-S过渡型花岗岩,是新生基性地壳低温条件下由于角闪石脱水分解而发生部分熔融而成,并混入了少量中-新元古代沉积组分,岩浆未发生明显的分离结晶作用,残留相为石榴石、角闪石和斜长石为主的麻粒岩;(4)该花岗岩形成于北祁连洋北向俯冲的活动大陆边缘背景之下,并在侵位上升过程中加入了部分沉积物质。     

天山地区夏季极端降水特征及气候变化

基于1961—2007年天山地区32站的逐日降水资料,分析了夏季天山地区极端降水事件的气候分布和时间变化特征.结果表明:夏季天山地区的极端降水量、极端降水日和极端降水比分布存在明显的区域差异.局地极端降水频繁,平均3～4d就有1次发生,大范围极端降水较少发生.连续性极端降水以1d为主.极端降水量在天山南北坡均随地形增加而增多,地形高度对降水的影响,北坡要大于南坡.在相同高度范围内,北坡极端降水量基本均大于南坡.天山地区的极端降水事件呈增多趋势,在1970年代中后期至1980年代中前期,极端降水事件为低值期,而1990年代是高值期.     

Final Closure Time of the Paleo‐Asian Ocean: Implication from the Provenance Transformation from the Yangjiagou Formation to Lujiatun Formation in the Jiutai Area,NE China

The Jiutai area is tectonically situated at the eastern segment of the Central Asian Orogenic Belt(CAOB) and is close to the North China Craton(NCC) to the south, serving as an ideal place to investigations of the closure of the PaleoAsian Ocean(PAO). Sandstone samples collected from the Yangjiagou Formation and the Lujiatun Formation in this area have been studied in detail in terms of petrology, geochronology and geochemistry. The maximum depositional time of the Yangjiagou and Lujiatun formations has been constrained to early Middle Triassic(ca. 245 Ma) and middle Late Triassic(ca. 219 Ma), respectively. The Yangjiagou Formation, with a major provenance of dissected island arcs, is dominantly composed of Phanerozoic sediments from Northeastern China(NE China) massifs. The Lujiatun Formation, with major sediments from active continental margins, has a relatively larger proportion of Precambrian sediments, in which the ～1.85 Ga and ～2.5 Ga sediments are typical of the crystalline basements of the NCC and NE China massifs, which were uplifted and eroded during the closure of the PAO. Besides, both formations show the enrichment in LREEs and the depletion in HREEs, the common Eu negative anomalies, and trace element contents similar to that of the upper continental crust. Based on the provenance analysis of these two formations, the final closure time of the PAO in this area is constrained as from the early Middle Triassic(ca. 245 Ma) to the middle Late Triassic(ca. 219 Ma).     

直流电弧原子发射光谱法测定钛和钛合金中微量杂质元素

高纯度的钛及钛合金具有良好的可塑性,当有杂质存在时变得脆而硬而影响其性能,准确分析杂质元素的含量有利于对钛生产工艺进行质量控制。对于杂质元素的分析,现行国家标准方法是采用样品蒸发温度较高的直流电弧作为光源,摄谱仪测定,需要经过显影、定影、测量黑度等步骤,操作繁琐,流程长,测量误差较大。本文应用中阶梯光栅和电荷耦合器件(CCD)组成的直流电弧(DC Arc)原子发射光谱仪(波长范围200~800nm),谱线干扰分析和谱线强度测量可以同时进行,能更大限度地获取光谱信息,建立了快速测定钛及钛合金中10种微量杂质元素(锰锡铬镍铝钼钒铜锆钇)的分析方法。实验讨论了测定过程中的四类谱线干扰,包括钛作为基体元素的谱线干扰、钛合金中添加的化学成分元素干扰、铁谱线的干扰、杂质元素之间的干扰,确定了适当的分析线;并应用一种浅孔薄壁细颈杯形电极装入试样,提高了样品的蒸发效果;用氯化银和碳粉的混合物作缓冲剂,提高了待测元素的谱线强度。本方法的检测范围为0.001%~0.06%,精密度小于15%,回收率为90.0%~110.0%,适合于大批量钛及钛合金样品中杂质元素的同时检测。     

Chemical Analysis of Water and the Resource of Br,K Prospects of Oilfield Brines from Ordovician and Carboniferous in Tarim,China

正China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of Ordovician     

近40年来气候变化对青海盐湖及其矿产资源开发的影响——以小柴旦湖为例

青海是中国盐湖主要分布区之一,蕴藏着丰富的矿产资源。文章以RS和GIS技术为基础,从20世纪70年代、90年代、2000年前后、2008~2009年和2013~2014年五期Landsat遥感影像中提取了青海面积大于10 km2的所有盐湖(不包括干盐湖),分析了其近40年来的变化趋势:总体上,盐湖总面积除在2000年前后有所减少外,基本上呈现增加的趋势;具体而言,2000年前后,萎缩的盐湖主要分布在柴达木盆地;其他时期均呈现全面扩张的趋势。在全球气候变暖的大背景下,通过分析青海地区11个气象台站的年平均气温、年降雨量和蒸发量数据,可知青海地区气候呈现了向暖湿方向转型的趋势,且2002年之后更为明显。最后,以青海省小柴旦湖为例,分析了湖泊淡化、矿产资源贫化对盐湖资源开发的影响,具体为:1资源开发成本升高、难度加大,甚至使一些处于工业开发临界品位的盐湖失去开发价值;2盐湖淡化条件下,锂等矿产资源有效提取技术亟待研发;3政府制定矿产资源开发政策时,需要对气候及盐湖的动态变化过程综合考虑。以上说明,青海地区的暖湿气候使盐湖大幅度淡化,给盐湖矿产资源开发带来了新的挑战。