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1.
Dan Zhang Hui Liu Ying Liang Cheng Wang Hecheng Liang Hesheng Cai 《Frontiers of Earth Science》2009,3(1):73-79
Samples of groundwater were collected from 17 sites in the Jianghan plain in July 2007. Sixteen phthalate esters (PAEs) were
detected in samples collected by using solid-phase extraction (SPE)-gas chromatography (GC). The results show that there were
one or several PAEs in all the samples, and the concentrations of total PAEs ranged from 80.12 to 1882.18 ng/L. Four PAEs,
i.e. di-isobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), bis (2-ethoxyethyl) phthalate (BEEP) and di (2-ethylhexyl)
phthalate DEHP) were the dominant species. Among these, DIBP, DBP and DEHP concentrations were closely related to the water
supply from the Yangtze River, Hanjiang River and Honghu Lake. However, the distribution of BEEP was irregular, which may
be due to the application of some kind of products containing BEEP in the related areas. PAE distribution was irrelevant to
the electrical conductivity and sample depth. 相似文献
2.
Shekhar Gupta P. S. Dandele M. B. Verma P. B. Maithani 《Journal of the Geological Society of India》2009,73(2):202-212
Groundwater in Palnad sub-basin is alkaline in nature and Na+-Cl−-HCO3− type around Macherla-Karempudi area in Guntur district, Andhra Pradesh. Total dissolved solids (TDS) show strong positive
correlation with Cl−, Na+, Ca2+ and Mg2+, and positive correlation with SO42−, K+ and HCO3−. Calcareous Narji Formation is the dominant aquifer lithology, and water-rock interaction controls the groundwater chemistry
of the area. Chloro-alkaline indices (CAI) are positive at Miriyala, Adigopula, Mutukuru, Macherla and Durgi suggesting replacement
of Na+ and K+ ions from water by Mg++ and Ca++ ions from country rock through base exchange reactions. Negative CAI values are recorded at Terala, Rayavaram and Nehrunagar,
which indicate exchange of Na+ and K+ from the rock as cation-anion exchange reaction (chloro-alkaline disequilibrium).
TDS range from 91 to 7100 ppm (Avg. 835 ppm) and exceed the prescribed limit of drinking water around Mutukuru, Durgi, Rayavaram,
Khambampadu and Ammanizamalmadaka areas. Scanty rainfall and insufficient groundwater recharge are the prime factors responsible
for high salinity in the area. Fluoride content ranges from <1 to 3.8 ppm and contaminated areas were identified around Macherla
(1 sq km; 3.8ppm), Mandadi (1 sq km, 2.1ppm) and Adigopula (2 sq km, <1 to 3.7 ppm). The % Na+ content varies from 17 to 85 with the mean value of 57, and eighty (80) samples showed higher %Na+ in comparison to the prescribed limit of 60 for irrigation water. Sodium Adsorption Ratio (SAR) and % Na+ in relation to total salt concentration indicate that groundwater (51%) mostly falls under doubtful to poor quality for irrigation
purpose. Groundwater of Adigopula village is fluoride contaminated and remedial measures are suggested to improve the water
quality. 相似文献
3.
高精度测定渗透系数（K）的重要性不言自明,但是现阶段野外试验手段能够提供的关于K的信息不能满足高度非均质地层中污染物迁移预测模拟的需求。直接推进注入记录器(Direct Push Injection Logger, DPIL)和直接推进渗透仪(Direct Push Permeameter, DPP)是新发展的水文地质参数测量仪器,能够使K值的测定达到前所未有的分辨率和成本效益水平。工具向地下推进过程中,通过对注水量、注水压力和其它的水文地球物理参数的同步监测,直接推进技术(Direct Push, DP)能快捷准确地获得地层渗透系数的垂向分布。DP技术几乎适用于所有野外松散地层,并且对场地的干扰很小。因此,它克服了许多基于既有井的传统含水层测试方法的局限性。最近在美国MADE试验场的一个案例研究表明,使用DPIL/DPP可以获得空间分辨率达15cm的K值垂向分布。未来,高精度直接推进技术还可以与新一代的地球物理技术,例如高精度探地雷达相结合,以实现不同位置DP测定K值的互联以及整个试验场K值三维分布的确定。 相似文献
4.
Aquatic humic substances (AHS) have been intensively studied because they have a number of significant biogeochemical functions in water chemistry. In order to evaluate such functions, which are regulated by their quantity and quality, a quantitative understanding of AHS is necessary. This study shows the seasonal and vertical changes in the AHS concentration in Lake Biwa, the largest monomictic lake in Japan, over 4 years. The concentration of dissolved organic matter carbon (DOM-C) and AHS carbon (AHS-C) ranged from 0.85–1.6 mg C/l and 0.32–0.71 mg C/l, respectively. The percentages of AHS-C in the DOM-C ranged from 32% to 65%. At all depths, the DOM-C decreased and the AHS-C slightly increased or remained at nearly the same level, suggesting that the quality of the water may have changed mainly due to changes in the composition of the organic matter. Although the AHS-C to DOM-C ratio fluctuated and had no seasonal tendency, the average AHS-C ratio increased during the 4 year monitoring period. Because AHS can influence the entire food web starting with phytoplankton, unraveling the mechanism by which they accumulate remains an important goal. 相似文献
5.
游远航 《吉林大学学报(地球科学版)》2015,45(4):1205-1216
为了解广州地区蔬菜基地有机污染物的分布情况,选取了6个代表性基地进行调查采样,测试分析了表层土壤、蔬菜及灌溉水中15种邻苯二甲酸酯(PAEs)化合物、16种多环芳烃(PAHs)化合物和19种有机氯农药(OCPs)化合物的质量分数及质量浓度.结果表明:在15种PAEs化合物的总质量分数(w(ΣPAEs))中,土壤样品为158.0~4 321.0 ng/g,蔬菜样品为1 134.0~48 576.0 ng/g;水样中15种PAEs化合物的总质量浓度(ρ(ΣPAEs))为632.0~14 271.0 ng/L;就单个化合物而言,以DiBP、DBP、DEHP三种污染物为主,其三项之和占所有PAEs质量分数的97.5%~99.1%;在16种PAHs化合物的总质量分数(w(ΣPAHs))中,土壤样品为28.48~1 121.96 ng/g,蔬菜样品为238.09~1 000.61 ng/g;水样中16种PAHs化合物的总质量浓度(ρ(ΣPAHs))为338.21~1 239.78 ng/L;在19种OCPs化合物的总质量分数(w(ΣOCPs))中,土壤为0.04~71.28 ng/g,蔬菜为1.08~9.18 ng/g.总体上看,各基地土壤中DBP质量分数均超标,多环芳烃类在灵山、花东、黄埔菜地土壤中存在轻微污染,有机氯农药均未出现污染. 相似文献
6.
Ian Shennan 《第四纪科学杂志》1986,1(2):155-179
Stratigraphic, micropalaeontologic and radiocarbon data show that since c. 6500 BP the Fenland has been influenced by 7 periods of positive sea-level tendencies and by 6 periods of negative sea-level tendencies. Despite the numerous problems associated with the reconstruction of past altitudes of sea level the periods of positive sea-level tendencies were clearly characterised by a rise in sea level, the development of transgressive overlaps and a landward movement of the coastline. The periods of negative sea-level tendencies were characterised by the development of regressive overlaps, a seaward movement of the coastline and a reduced or negative rate of sea-level rise. The various altitudinal errors do not permit the incontrovertible distinction of periods of falling sea levels. All changes within the Fenland were not synchronous and local factors influenced the exact nature of each sea-level indicator. Dominant regional and local factors have been identified for different areas and different time periods. The chronological and spatial characteristics of the sequences within the Fenland are best explained by a palaeocoastline without supratidal barriers controlling sedimentation. The data indicate an average crustal subsidence in the Fenland of 0.9m/1000 years since c. 6500 BP and the pattern of positive and negative tendencies of sea-level movement is also seen in the chronologies for north west England and north east Scotland. 相似文献
7.
提出了以聚四氟乙烯(PTFE)为氟化剂,氟化辅助ETV-ICP-AES测定难熔元素Nb、Ta、Zr和U的新方法。对待测元素的氟化蒸发行为进行了研究,并探讨了其相应的氟化蒸发机理。该法测定Nb、Ta、Zr和U的线性范围达4个数量级,检出限分别为50、90、16和120pg。 相似文献
8.
原煤尾气和煤渣中多环芳烃相关性测定 总被引：2，自引：0，他引：2
对原煤、尾气和煤渣中多环芳烃进行了相关性测试。在模拟工业锅炉代表性燃烧条件下将烟煤和无烟煤样品在管式炉中燃烧，分别采用ＧＣＭＳ和ＨＰＬＣ法对原煤、尾气和煤渣中的多环芳烃种类和含量进行了定性和定量测定。通过在特定条件下某一煤种中多环芳烃种类、含量在燃前、燃后变化的相关性，探索煤中多环芳烃在燃烧过程中的衍变规律 相似文献
9.
10.
采自西藏阿里地区五县市几个层位的腹足类化石分属早奥陶世、早石炭世、早二叠世、早白垩世(多数)、晚白垩世(少数)及第三纪等时限;共计31种(包括12个新种、3个相似种、8个未定种),归入26属(包括1新属),分属14科。它们的地理分布及与它区的对比也略予论述。 相似文献
11.
Petrological Significance of Zoned Plagioclase in Eldjurti Granite and Mafic Microgranular Enclaves,North Caucasus,Russia 总被引：5，自引：0，他引：5
朱永峰 《中国地球化学学报》1994,13(2):142-155
Plagioclase phenocrysts from mafic enclaves and plagioclase from its host granite possess a pat-tern of complex zonation .A plagioclase phenocryst can generally be divided into three parts:an oscillatory, locally patchy zoned core (An47-19),a ring with dusty, more calcic plagioclase (An64-20) and a normally zoned rim composed of sodic plagioclase (An22-3.3). Major discontinuities in zoning coincide with resorption surfaces that are overgrown by the more calcic plagioclase.The cores of large plagioclase phenocrysts from mafic enclaves and host granite show similar zoning patterns and similar compositions, indicating their crystallization under the same conditions .Steep normal zoning of the rims of plagioclases both from host granite and mafic enclaves illustrates a drastic decrease in An content which is considered to have resulted from the continuous differentiation of hybrid magma and efficient heat loss because of the upward emplacement of the residual magma.Wide rims of plagioclases from the host granite against the discrete rims of plagioclases from mafic enclaves indicate that differentiation and cooling lasted much longer in the host granite than in the mafic enclaves. 相似文献
12.
13.
Mike Müller-Petke 《中国地质大学学报(英文版)》2009,20(3)
In this review article, we present recent developments and Improvements in magnetic resonance sounding (MRS), a newly established geophysical exploration method that provides unique information about hydrogeophysical properties due to its direct sensitivity to hydrogen protons and proton dynamics. Starting with the most sophisticated and complete MRS formulation, we give a detailed view on how to solve the equation, i.e., inverting exactly for all model parameters: water content, decay time, and resistivity. Giving a short review of general inversion schemes used in geophysics, the special properties of MRS inversion are evaluated and the development of MRS inversion over recent years is shown. We present the extension of MRS to magnetic resonance tomography (MRT), i.e., the extension to two-dimensional investigations and appropriate inversions. Finally, we address restrictions, limitations, and inconsistencies as well as future developments. 相似文献
14.
磁电法作为一类特点明显的电磁勘探方法在外国(美国、加拿大、澳大利亚等)已经有了成熟的应用,但是该类方法在我国应用研究较少,甚至不为众人所知。本文从数据采集与分析、正反演技术以及应用现状3个方面详细介绍了国内外磁电法的技术原理和发展现状;总结了磁电法的优缺点及适用的条件,对于我国未来磁电法的发展提出了建议。综述表明:1)目前地面数据采集为中梯方式,可以借鉴其他应用成熟的电磁法观测方式;2)磁电法从静电场理论出发无法得到绝对电导率,可以尝试频率域理论;3)地面数据的深度分辨能力需要提高,可以通过多源多分量三维反演来提高反演的准确性;4)建议在国内将磁电法的应用范围扩展到井中、海洋以及环境和工程领域。 相似文献
15.
应用宁夏气象台站1961-2010年逐候降水量序列资料, 计算了春、夏、秋季3个季降水的集中期、集中度和干旱Z指数, 运用趋势分析、相关分析、合成分析讨论了3季的集中期、集中度与旱涝程度的时空变化特征及其相互关系. 结果表明: 50 a来宁夏春夏秋干旱等级均呈加剧趋势, 秋季加剧更明显, 3季中中部干旱带加剧最严重, 南部山区次之, 北部最小. 春季集中期无明显变化趋势, 但集中度有上升趋势, 夏季集中期、集中度缓慢下降, 秋季集中期、集中度变化不明显;近10 a来3季集中度明显增大, 春夏两季集中期推迟. 春季降水集中度对干旱没有显著影响, 但首场透雨出现早晚对干旱影响显著, 透雨出现偏早, 干旱等级低, 反之亦然;夏季集中期对干旱影响不显著, 但集中度显著影响干旱, 集中度高, 雨涝发生概率越大, 集中度低, 干旱发生概率大;秋季集中期、集中度对干旱都有影响, 集中度高, 集中期早, 雨涝发生概率大, 反之干旱出现概率大. 相似文献
16.
雪峰山西侧地带的地洼型造山-造盆作用 总被引：4，自引：2，他引：4
在晚三叠世前长期处于地台体制的雪峰山西侧地带,上三叠统和中-新生界的沉积相、物质成分、构造变动和地台构造层的构造变动反映,这里于地洼阶段发生了强烈的造山-造盆作用,造成了当今海拔反差达约千米的盆、山景观。这类地洼型造山-造盆作用具有多种运动方式。 相似文献
17.
Petrogenesis of the granite related to the Baishaziling Sn deposit,Dayishan ore field,Southern China
Zhuang Zhao Xiaoyong Yang Wanying Li Tuyan Zhang Youyue Lu Zunzun Zhang 《Chemie der Erde / Geochemistry》2022,82(2):125873
The Baishaziling greisen-type tin deposit is located in the Dayishan ore field, Nanling Range, Southern China. In this study, for the first time, we present both zircon and cassiterite UPb dating, whole-rock elements, zircon LuHf and apatite Nd isotopic compositions to better constrain the petrogenesis of granite and its genetic link with Sn mineralization. Zircon UPb ages of fine-grained granite and coarse-grained granite are 154 ± 1.8 Ma and 153 ± 2.1 Ma, respectively, which are consistent with the cassiterite UPb dating of 154 ± 5.4 Ma, implying genetic relationship between the Baishaziling granite and tin metallogenesis. The Baishaziling granites exhibit high SiO2, K2O + Na2O, Zr + Nb + Ce + Y contents, low P2O5 and Sr contents, and high ratios of Ga/Al, TFeO/(TFeO + MgO), implying A-type granite affinity with characteristics of high-K calc-alkaline and weakly peraluminous. The zircon εHf(t) values and apatite εNd(t) values of the granite vary from ?4.46 to ?1.81 and ?8.37 to ?7.10, with two-stage Hf and Nd model ages of 1.40 to 1.50 Ga and 1.52 to 1.64 Ga, indicating that they were generated by the partial melt of the Proterozoic basement with the involvement of mantle magma. In addition, formation of Dayishan granite was likely associated with an intraplate extensional setting caused by the subduction of the Palaeo-Pacific plate. The Baishaziling reduced granites have high stannum and boron contents, which are in favor of the tin mineralization. 相似文献
18.
《China Geology》2021,4(3):463-475
Ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and anaerobic ammoniaoxidation (anammox) bacteria are very important contributors to nitrogen cycling in natural environments. Functional gene abundances of these microbes were believed to be well relevant to N-cycling in groundwater systems, especially in the Pearl River Delta (PRD) groundwater with unique high intrinsic ammonia concentrations. In this research, 20 sediment samples from two in the PRD were collected for porewater chemistry analysis and quantification of N-cycling related genes, including archaeal and bacterial amoA gene and anammox 16S ribosomal Ribonucleic Acid (rRNA) gene. Quantitative Polymerase Chain Reaction (qPCR) results showed that gene abundances of AOA, AOB, and anammox bacteria ranged from 3.13×105 to 3.21×107, 1.83×104 to 2.74×106, and 9.27×104 to 8.96×106 copies/g in the sediment of the groundwater system, respectively. Anammox bacteria and AOA dominated in aquitards and aquifers, respectively, meanwhile, the aquitard-aquifer interfaces were demonstrated as ammonium-oxidizing hotspots in the aspect of gene numbers. Gene abundances of nitrifiers were analyzed with geochemistry profiles. Correlations between gene numbers and environmental variables indicated that the gene abundances were impacted by hydrogeological conditions, and microbial-derived ammonium loss was dominated by AOA in the northwest PRD and by anammox bacteria in the southeast PRD.© 2021 China Geology Editorial Office. 相似文献
19.
J Rullktter D Leythaeuser B Horsfield R Littke U Mann P.J Müller M Radke R.G Schaefer H.-J Schenk K Schwochau E.G Witte D.H Welte 《Organic Geochemistry》1988,13(4-6)
Four shallow boreholes were drilled in the Hils syncline, northern Germany, in order to determine quantitatively the amount of hydrocarbons generated and expelled during maturation of a typical kerogen-type-II-bearing source rock. The holes penetrated the carbonceous Lias shales (Posidonia shale, Lower Toarcian) and part of the adjacent Dogger α and Lias δ mudstones. The maturity of the organic matter in the cores recovered ranges from immature (0.48% R̄0) to overmature 1.45% R̄0) due to location of the Hils syncline in the vicinity of the Vlotho Massif, which is deep-seated intrusive body. Facies variations of the Lias within the short geographical distances in the study area are negligible.Organic matter mass balance calculations were based on detailed organic geochemical analyses of residual material in the Lias shales (kerogen, bitumen etc.) and on the evidence of a uniform initial composition of these sediments in the study area. Dead carbon determinations supported this latter criterion but were not used as a parameter in the calculations.About 50% of the initial kerogen was transformed into oil, gas and inorganic compounds during the vitrinite reflectance increase from 0.48 to 0.88% R̄o and only marginally more during the maturity increase from 0.88 to 1.45% R̄o. Only a small portion of the generated material remained in the source rock even at a relatively early stage of generation (0.68% R̄o). Expulsion efficiency of oil plus gas reached a value of 86% at the end of the main generation stage (0.88% R̄o). 相似文献
20.
黄山–镜儿泉地区位于新疆东天山东部,是我国重要的铜镍成矿带之一。本次研究以该区1∶20万勘查地球化学数据中的Ni、Cu、Co、V、Ti、Cr、Mg O和Fe_2O_3等8个元素或氧化物作为研究对象,采用主成分分析(PCA)、能谱-面积分形方法(S-A)以及局部奇异性分析(LSA),对与岩浆型铜镍硫化物矿床有关的元素分布特征进行分析,以及对异常进行识别。结果表明:(1)第一主成分(PC1)的方差贡献占总体方差贡献的62.9%,各元素均有较高的正载荷,在空间上与已知铜镍硫化物矿床具有较好的对应关系,可以作为找矿的指示标志;(2)PC1空间分布的复杂性,可能是地质过程、成矿过程以及表生过程综合作用的结果;(3)基于自相似性原理,通过对PC1的复杂场分离以及弱异常增强,发现PC1异常带或PC1异常的奇异值均与NEE向的深大断裂相对应。综合成矿地质条件以及异常带分布特征,认为与康古尔–黄山深大断裂、雅满苏深大断裂以及阿奇克库都克深大断裂等相对应的一系列NEE向的PC1异常带是进一步找矿的有利地段,可优先部署工作。 相似文献