中国典型水域磺胺类合成药物的环境生物地球化学特征

作为广谱抗菌的人工合成药物——磺胺类(SAs)是应用最早的一类人工合成抑菌剂之一,被广泛用于人类医疗、禽畜及水产养殖等。大量磺胺类药物的应用随代谢进入水环境中,对水生生态系统和人类健康产生重要影响并构成潜在风险,截至目前,这些影响和风险并未被探明。因此,对8种典型磺胺类合成药物在我国典型水环境中的分布特征进行了阐述,评估了它们对不同水生生物的生态毒性及生态风险,并诠释了它们在生物体内的代谢及其在生态系统中的降解途径。结果表明,不同水环境中磺胺类合成药物的浓度分布差异显著,磺胺甲恶唑和磺胺嘧啶分别在水体及沉积物中的浓度和污染程度最高;水体藻类是磺胺类合成药物最敏感的水生物种,其次是甲壳类和鱼类,磺胺甲恶唑对水生生态系统构成高风险;磺胺类合成药物进入体内后被代谢成不同的产物,与母体合成药物一同进入水环境中经历降解过程;生物降解是水生生态系统中磺胺类合成药物去除的主要途径,不同种细菌、真菌及藻类均可降解磺胺类合成药物。在以后的研究中,应当进一步加强磺胺类合成药物对水生生物的慢性毒性以及合成药物混合毒性的研究,明晰水环境磺胺类合成药物的分布-代谢-传输-效应的综合过程,探析磺胺类合成药物在水生...     

黄土高原西部弃耕地植被恢复与土壤水分调控研究

选择黄土高原半干旱偏旱区2 a、3 a、4 a、5 a、7 a、9 a、12 a、20 a的弃耕台地和天然台地,调查各弃耕地和天然台地的植物种类、数量、盖度、频度和地上生物量,定期采样分析各样地0~100 cm土层土壤水分。结果表明：农田弃耕后植被沿天然植被方向演替,在演替过程中,植物种类数量逐渐增加,但在弃耕9 a后开始减少,20 a后接近于天然台地;更耐旱的多年生草本和小灌木种增加;除7~9 a波状变化外,植被盖度和地上生物量呈逐渐减少趋势,弃耕初期的植被盖度和地上生物量显著大于弃耕12 a后和天然台地;12 a和20 a弃耕地0~100 cm土层含水量高于其他弃耕地和天然台地,弃耕初期表层土壤含水量较高,天然台地含水量居中,但其植被对水分利用的时间延长,范围扩大,表明天然台地植被的水分利用率提高,植被群落更加稳定。     

西藏多龙矿集区铜金流体演化过程探讨 ——来自硫同位素的证据

西藏多龙矿集区发育世界典型的斑岩铜矿系统,文章选取区内多个代表性矿床开展硫同位素研究,并结合前人数据,为探讨该成矿系统成矿物质来源、流体演化过程提供了新证据.研究表明,波龙、拿若、拿厅、拿顿和铁格隆南矿床δ34S平均值相似(接近于0),指示含矿岩浆提供了各矿床所需的硫元素.此外,区内典型矿床流体演化过程可分为2类:①流体演化主要受控于温度变化,表现为δ34S随温度降低而降低(如拿顿矿床);②流体演化受温度和氧化还原状态共同影响,表现为δ34S随温度降低而升高(如:波龙和拿若矿床),或是随温度降低,δ34S波动变化范围较大(如拿厅和铁格隆南矿床).结合岩相学证据,文章推测热液体系氧化还原状态的变化是由水岩反应所导致,最后,文章提出多龙矿集区内矿化阶段硫化物通常具有较低的δ34S,指示成矿流体为高氧化性流体,并且该特征在类似矿床的找矿勘查工作中也可发挥积极的指示作用.     

Early Cretaceous precious fossil-bearing beds in Weijialing－Yaolugou of Jianchang Basin , western Liaoning

The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning. The fossil-bearing horizons are mainly in the Yixian- and J iufotang formations. In the Weijialing－Yaolugou of southwest Jianchang Basin, many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation. The geologic setting, sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.     

深港西部通道填海区地下水铜、钒、铊、镉、钨迁移的实验研究

填海工程使滨海地区的地下水物理化学条件改变,导致该区域地下水中重金属浓度升高。本文以深港西部通道填海区为例,采用实验室模拟填海条件的办法,初步探讨了影响填海区地下水重金属迁移的关键因素。模拟实验结果表明,填海区地下水中钨元素含量升高与地下水淡化、淤泥氧化过程以及填料风化有关;铜元素含量升高则与淤泥氧化过程以及填料风化有关;钒元素含量升高与地下水淡化和淤泥氧化过程有关,而其他元素含量升高则主要与填料风化释放有关。     

A Comparison Study on the δD Value of Polycyclic Aromatic Hydrocarbons in Hydrous Pyrolysate of Herbaceous Peat with Different Water Medium

To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds, a series of hydrous pyrolyses were conducted on herbaceous peat. Polycyclic aromatic hydrocarbons (PAHs) in hydrous pyrolysed samples and their hydrogen isotopic composition characteristics were studied. The aqueous medium demonstrated a significant influence on the hydrogen isotopic composition of the individual PAHs generated during pyrolysis. The results showed that the PAHs formed after pyrolysis in the presence of a saltwater medium with high δD value from a salt lake had a heavy hydrogen isotopic composition. The PAHs formed after pyrolysis in the presence of a fresh water medium with low δD value from a swamp had a light hydrogen isotopic composition. The difference in the average PAH δD value between the two hydrous experiments varied from –174‰ to –109‰, suggesting that the hydrogen isotopic composition of individual sedimentary PAHs can reflect the source of the diagenetic water medium. In addition, a comparative study found that the hydrogen isotopes of PAHs were superior to those of n-alkanes in the same sample for diagenetic water indications. The results indicated that the exchange of water-derived inorganic hydrogen and organic hydrogen was more intensive in freshwater experiments than in saltwater experiments. With an increase in the simulation temperature, the average δD value of PAHs generated in the hydrous simulation experiments showed an increasing trend, reflecting that the δD value of sedimentary PAHs formed with the participation of diagenetic water media was still closely related to the thermal maturity of organic matter. Comparative studies showed that the δD values of different types of organic compounds produced by hydrous pyrolysis of peat were in the order, PAHs > n-alkanes > methane.     

安徽滁县琅琊山一带燕山期岩浆岩成因及区域找矿方向

滁县琅琊山铜矿床是长江中下游成矿带北东段滁县-庐江铜金成矿带的一部分,为安徽东部目前发现规模最大的铜及伴生金矿床.与成矿关系密切的滁县岩体,长期以来前人鲜有系统的地球化学研究,本文在野外地质调查的基础上,系统采集了一套滁县岩体样品,发现其地球化学特征与典型的埃达克岩基本一致:具有SiO2＞56％,Al2O3≥15％,富Sr、Ba和Cr、Ni,具有高的Sr/Y和(La/Yb)N值,但Y和Yb含量低,无明显Eu异常,另外岩石具有较高的MgO、Mg#及Sr/La值,显示海水蚀变MORB相似的地球化学特征.分析认为,该区燕山期岩浆岩为洋壳俯冲产物,属比较典型的和成矿有关的埃达克岩,伴随着该期侵入岩的上侵,富含Cu、Au的成矿物质随着温度、压力或者氧逸度的降低,在合适的部位富集成矿.对比分析了上腰铺岩体的地球化学特征,认为它和滁县岩体特征基本一致,应该有着相似的成岩成矿背景.同时在滁县岩体西南段发现一条含微细粒黄铁矿碎裂状白云岩质硅化带,在上腰铺岩体周边发现一条多金属矿化硅质脉,并对琅琊山含铜矿化矽卡岩及上述白云岩质硅化带和多金属矿化硅质脉进行了地质分析和痕量元素测试,认为它们与燕山期侵入岩有着密切的关系,上腰铺岩体周边可以作为下步铜及伴生金矿床勘查的新的远景地区,同时指出该区找矿不能只盯着矽卡岩型铜金矿而忽视多金属矿化硅质脉新类型矿的寻找.     

Geological and Geochemical Constraints on the Newly Discovered Yangchongli Gold Deposit in Tongling Region, Lower Yangtze Metallogenic Belt

The newly discovered Yangchongli gold deposit is a unique independent gold deposit in the Tongling ore-cluster region controlled by the tectonic alteration firstly discovered in the Lower Yangtze Metallogenic Belt(LYMB). The host magmatic rocks mainly consist of monzodiorite and K-feldspar granite. The LA-ICP-MS U-Pb zircons dating yielded weighted mean ~(206)Pb/~(238)U ages of 140.7 ± 1.8 Ma and 126.4 ± 1.2 Ma for the monzodiorite and K-feldspar granite, respectively. Monzodiorites are enriched in Sr, Ba, Rb, and depleted in Y, Yb with high Sr/Y and La/Yb ratios, similar to the geochemical features of adakite, considered as products of differentiation of mafic magmas originating from lithospheric mantle melt/fluids caused by metasomatism during paleo-Pacific Plate subduction in the Mesozic. In contrast, the compositions of K-feldspar granites are A-type granites, indicating an extensional tectonic background. Gold ores hosted in the fracture zone occurred as quartz vein within cataclastic rock. Sulfur and lead isotopes from pyrites show crust-mantle mixing characteristics. Metal components from strata also took part in the gold mineralization, and resulted from two episodes of magmatism that were probably related to tectonic transition from a compressive to an extensional setting between 140–126 Ma, which led to the Mesozoic large-scale polymetallic mineralization events in eastern China.     

Fine upper crustal structure of Jiashi strong earthquake swarm region in Xinjiang inferred from high resolution seismic refraction profile data

Introduction Jiashi-Artux area in southwest Xinjiang is one of the most active earthquake provinces at pre-sent in Chinese mainland. In the last century, about 3/4 strong earthquakes in Chinese mainland hit this area, and especially from January 21 to April 16 in 1997, 7 earthquakes with the magnituderanging from 6.0 to 6.9 occurred in a very small area of 9 km×18 km near Jiashi (ZHU et al, 1998). It has never taken place before in Chinese mainland that a series of strong earthquakes shoo…     

高空急流对一次强沙尘暴过程沙尘传输的影响

使用GRAPES_SDM沙尘暴数值模式,对2011年4月28-30日中国北方强沙尘暴天气进行分析,讨论高空急流在此次过程中对沙尘传输的影响,得出以下结论:（1）GRAPES_SDM沙尘暴模式较好地模拟了此次沙尘暴过程的范围和强沙尘暴中心,整体模拟效果较好;（2）沙尘天气发生时间及移动路径与200 hPa高空急流的加强、移动发展有很好的对应关系;（3）高空强纬向风速的加强能够促使中低层形成垂直环流圈,其下沉支流使高空动量有效下传到近地面,进而在地面形成大风及扬沙和沙尘暴天气,强沙尘暴中心位于此垂直环流圈的下沉支;（4）等熵位涡与高空急流及地面沙尘浓度分布演变有很好的对应关系,等熵位涡位于高空急流北侧,地面沙尘浓度中心位于高空急流出口区、等熵位涡中心西南侧、等值线密集带;高层高值位涡区向下延伸的路径与高空急流北侧纬向风速等值线密集带有非常好的对应关系。本文还通过对高空急流轴线动力、热力结构垂直剖面的分析,探讨了高空急流对大范围沙尘天气影响的可能机制。