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地质元素与精神疾病的相关研究 被引量:1
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作者 张奎 刘振华 +6 位作者 王永红 程伟 蔡海涛 杜学永 王砚英 郭艳梅 葛晓立 《精神医学杂志》 2011年第2期138-140,共3页
目的探讨地质元素和精神疾病的关系。方法采用相关分析方法,分析地质元素与精神疾病总患病率、精神分裂症患病率、情感性精神障碍患病率、精神发育迟滞患病率之间的关联。考虑到地质元素和地域环境有关,又分为平原、丘陵、山区三种地质... 目的探讨地质元素和精神疾病的关系。方法采用相关分析方法,分析地质元素与精神疾病总患病率、精神分裂症患病率、情感性精神障碍患病率、精神发育迟滞患病率之间的关联。考虑到地质元素和地域环境有关,又分为平原、丘陵、山区三种地质条件统计分析。结果 (1)精神疾病和镁、锂存在负相关,而和锌、铜存在正相关。(2)镁、锂对精神疾病的负相关,既表现为单独作用,也表现为和锌、铜比值上。(3)镁、锂、锌、铜对精神疾病的影响在山区、丘陵作用小,在平原地区作用大。(4)镁、锂、锌、铜对精神疾病的影响中,未见对精神分裂症的影响,可见对总患病率、情感性精神障碍、精神发育迟滞影响。尤其是精神发育迟滞更易受到镁、锂、锌、铜的影响。结论镁、锂、锌、铜在平原地区对精神疾病显示明显作用。精神疾病和锂、镁存在负相关,与锌、铜存在正相关。精神发育迟滞最容易受到元素影响,而精神分裂症不受元素影响。本课题提出高锌可能对精神疾病存在促发作用。 展开更多
关键词 地质元素 精神疾病
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以地质元素为核心的全域旅游发展研究
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作者 张东燕 《安阳师范学院学报》 2021年第5期46-50,共5页
旅游产业的快速发展,带来了旅游资源单一性与消费需求多元性的突出矛盾。文章分析了以地质元素为核心的全域旅游发展问题,通过分析发现地质资源全域化及其旅游资源的全域化是问题的核心。最后,借鉴国内先行发展全域旅游的地区经验,为国... 旅游产业的快速发展,带来了旅游资源单一性与消费需求多元性的突出矛盾。文章分析了以地质元素为核心的全域旅游发展问题,通过分析发现地质资源全域化及其旅游资源的全域化是问题的核心。最后,借鉴国内先行发展全域旅游的地区经验,为国内其他地区发展以地质元素为核心的全域旅游发展提出了若干对策。 展开更多
关键词 地质元素 全域旅游 地质资源 全域化地质旅游资源
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由地质元素预测空气环境质量方法研究
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作者 郭烨鹏 贾惠艳 马力 《上海环境科学》 CAS 2015年第4期154-156,159,共4页
收集地质元素与空气质量数据,应用支持向量机确定了氮、硫,磷、钾元素超标与空气质量之间的关系,建立应用地质内元素预测空气质量的模型。使用蚁群算法对模型进行优化,结果显示,蚁群算法提高了模型预测精度,可以广泛应用到空气质... 收集地质元素与空气质量数据,应用支持向量机确定了氮、硫,磷、钾元素超标与空气质量之间的关系,建立应用地质内元素预测空气质量的模型。使用蚁群算法对模型进行优化,结果显示,蚁群算法提高了模型预测精度,可以广泛应用到空气质量评价中。 展开更多
关键词 支持向量机 蚁群算法 空气质量 地质元素
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地质体内元素含量与水体质量的关系分析
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作者 代净 乔宁 《上海环境科学》 CAS 2016年第2期53-55,59,共4页
为分析地质体内元素超标与水体质量的关系,收集了18组统计数据,采用线性回归的数学方法进行分析,得出影响水体质量的元素包括:有机物、无机物、有毒物质和金属元素,并建立了通过以上元素预测水体质量的预测模型,该模型预计结果较... 为分析地质体内元素超标与水体质量的关系,收集了18组统计数据,采用线性回归的数学方法进行分析,得出影响水体质量的元素包括:有机物、无机物、有毒物质和金属元素,并建立了通过以上元素预测水体质量的预测模型,该模型预计结果较为可靠,精度较高。 展开更多
关键词 地质元素超标 水体质量 线性回归 饮用水健康
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电感耦合等离子体质谱法在地质矿物元素成份分析中的应用 被引量:1
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作者 成立 《中国金属通报》 2019年第11期139-139,141,共2页
地球科学的不断向前发展,意味着必须全面了解地质矿物中各种元素组份的含量,但地质矿物元素成份十分复杂,针对这一问题,提出电感耦合等离子体质谱法在地质矿物元素成份分析中的应用。首先,利用电感耦合等离子体质谱法,对地质矿物元素成... 地球科学的不断向前发展,意味着必须全面了解地质矿物中各种元素组份的含量,但地质矿物元素成份十分复杂,针对这一问题,提出电感耦合等离子体质谱法在地质矿物元素成份分析中的应用。首先,利用电感耦合等离子体质谱法,对地质矿物元素成份进行方法设计。而后,通过仿真实验证明电感耦合等离子体质谱法可以实现对地质矿物元素成份准确定量。 展开更多
关键词 电感耦合等离子体质谱法 地质矿物元素 成份分析 应用
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ICP-MS法同时测定地质样品中锗、镓、铟 被引量:3
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作者 刘伟洪 杨峰 《分析仪器》 CAS 2018年第6期46-49,共4页
采用HNO_3-HF-H_2SO_4-H_3PO_4溶样体系,硝酸提取样品,电感耦合等离子体质谱法同时测定地质样品中的Ge、Ga、In。考察了内标元素、分析同位素、溶样体系以及提取液对测定结果的影响。在优化的实验条件下,锗、镓、铟的方法检出限分别为0... 采用HNO_3-HF-H_2SO_4-H_3PO_4溶样体系,硝酸提取样品,电感耦合等离子体质谱法同时测定地质样品中的Ge、Ga、In。考察了内标元素、分析同位素、溶样体系以及提取液对测定结果的影响。在优化的实验条件下,锗、镓、铟的方法检出限分别为0.05、0.78和0.06μg/g,测定了国家标准物质中的Ge、Ga、In,各元素测定值均与其推荐值均吻合,RSD(n=12)均在8%以内,3种元素加标回收率在92%~109%之间。该方法操作简单、快速、准确,适用于大批量地质样品中锗镓铟的同时测定。 展开更多
关键词 地质样品稀有分散元素
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内蒙古乌拉山金矿田变质岩石的地球化学特征
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作者 陈小伍 王振华 刘萍 《矿床地质》 CAS CSCD 北大核心 2002年第S1期577-581,共5页
该文主要对内蒙古乌拉山金矿田几种变质岩系岩石的主要元素、微量元素和稀土元素含量及特征值进行了研究,并与世界主要变质地体进行了对比,总结了本区变质岩石的地球化学特征,确定了其原岩的形成环境,为深入研究内蒙古乌拉山金矿田的成... 该文主要对内蒙古乌拉山金矿田几种变质岩系岩石的主要元素、微量元素和稀土元素含量及特征值进行了研究,并与世界主要变质地体进行了对比,总结了本区变质岩石的地球化学特征,确定了其原岩的形成环境,为深入研究内蒙古乌拉山金矿田的成因奠定了基础。 展开更多
关键词 元素地质化学 变质岩 乌拉山金矿田
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Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China 被引量:11
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作者 TAN Wen-Feng LIU Fan +2 位作者 LI Yong-Hua HU Hong-Qing HUANG Qiao-Yun 《Pedosphere》 SCIE CAS CSCD 2006年第1期72-81,共10页
Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and funct... Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-manganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules. 展开更多
关键词 elemental composition geochemical characteristics iron-manganese nodule soil
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基于改进共轭梯度BP法的化探矿床预测系统开发 被引量:1
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作者 马腾 周仲礼 +1 位作者 陈秀荣 秦飞龙 《软件》 2012年第11期81-84,共4页
在化探数据的采集中,常常会受到很多人为因素的影响。因此,为了既能体现采集参数的客观性又能真实反映地质演变的复杂性,本文以化探元素组合为预测矿床类型的依据,对这一预测过程采用神经网络建模,并进行系统开发。同时考虑到网络的效... 在化探数据的采集中,常常会受到很多人为因素的影响。因此,为了既能体现采集参数的客观性又能真实反映地质演变的复杂性,本文以化探元素组合为预测矿床类型的依据,对这一预测过程采用神经网络建模,并进行系统开发。同时考虑到网络的效率及稳定性,对于传统BP网络进行调整,用改进的共轭梯度法取代最速下降法,经结果测试及检验显示,新模型具有效率高,稳定性强的特点,从而有力推动了化探预测矿床类型的客观性与可行性。 展开更多
关键词 数学地质 化探元素组合数学地质 改进共轭梯度法神经网络 矿床类型预测
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Concentration, Distribution, and Occurrence of REEs in Coals from Chongqing,Southwest China 被引量:5
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作者 LI Da-hua TANG Yue-gang +3 位作者 CHEN Kun DENG Tao CHENG Fang-ping LIU Dong 《Journal of China University of Mining and Technology》 EI 2005年第3期227-233,共7页
The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coalsin different geological periods from Chongqing were studied. The results show that the REE content in coals ... The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coalsin different geological periods from Chongqing were studied. The results show that the REE content in coals fromChongqing is much higher than that of the ordinary Chinese coals, the Late Paleozoic coals from North China, UScoals, and the world coals. Although the concentration of light rare earth elements (LREE) is higher than that of heavyrare earth elements (HREE), the ratio of LREE to HREE is as low as 5.11. The REE content decreases with thecoal-formation periods from old to new. The REE content in the Sinian stone coal is the highest, but it is the lowest inEarly Jurassic coals. The similar REE contents in bituminous coals and anthracite show that the metamorphism has alittle influence on REE content in coal. In addition, silicate association dominates the occurrence mode of REEs incoals from Chongqing. 展开更多
关键词 coal rare earth elements CONCENTRATION CHONGQING
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Geochemical evidence of paleogeography and paleoclimate during deposition of the 2nd Member of Kongdian Formation in Kongnan area
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作者 Qinghua YAN Jing SUN Xudong ZHANG Qinglong MENG Man WANG 《Global Geology》 2007年第1期48-54,共7页
The 2nd Member of Kongdian Formation has been made up of a large number of oil shale and mudstone in the Kongnan aera of Huanghua depression around the Bohai Bay.In the Kongnan area,the lake basins were very large and... The 2nd Member of Kongdian Formation has been made up of a large number of oil shale and mudstone in the Kongnan aera of Huanghua depression around the Bohai Bay.In the Kongnan area,the lake basins were very large and deep during the deposition of the 2nd Member of Kongdian Formation.During that period,the lakes were sealed,uncommunicated with the sea water and the paleoclimate was very warm and wet in Kongnan area.Analyzing the content of the trace element and the rare earth element,carbon and oxygen isotope in the disquisition,The authors prove the two views correct. 展开更多
关键词 Kongnan the 2nd Member of Kongdian Formation trace element rare earth element carbonand oxygen isotopes PALEOCLIMATE PALAEOGEOGRAPHY
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Distribution characteristic and geological signiflcance of rare earth elements in Lopingian mudstone of Permian,Panxian county,Guizhou province 被引量:22
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作者 Shao Yubao Guo Yinghai +2 位作者 Qin Yong Shen Yulin Tian Li 《Mining Science and Technology》 EI CAS 2011年第4期469-476,共8页
In order to discuss the geochemical characteristic of REEs (rare earth elements) and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian (Late ... In order to discuss the geochemical characteristic of REEs (rare earth elements) and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian (Late Permian) mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs (185.56-729.46 ×10-6) is high. The ratios of w(LREE)/w(HREE) (6.84- 13.86) and W(La)N/w(Yb)N (1.01-3.02) show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w(∑REE)- w(La)/w(Yb) diagram. Moreover, abnormal surfaces near the sequence boundaries (SB2, SB3, SB4) are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w(LREE)/w(HREE), Eu/Eu* and Ceanom. 展开更多
关键词 Rare earth element Provenance Sequence boundary Lopingian Panxian county
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Rare earth element geochemistry of groundwater from a deep seated sandstone aquifer,northern Anhui province,China 被引量:2
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作者 Gui Herong Sun Linhua +1 位作者 Chen Luwang Chen Song 《Mining Science and Technology》 EI CAS 2011年第4期477-482,共6页
Deep coal mines in northern Anhui province, China, provide opportunities for tracing the distribution and fractionation of rare earth elements CREEs) in deep seated environments. Major ions, as well as REE concentrat... Deep coal mines in northern Anhui province, China, provide opportunities for tracing the distribution and fractionation of rare earth elements CREEs) in deep seated environments. Major ions, as well as REE concentrations were measured in groundwater from a sandstone aquifer located between -400 and -280 m. Our results indicate that this groundwater consists of CI.HCOH-Na or CI.CO3-Na water types with warm temperature (30.1-31.4~C), circumneutral pH (7.27-8.61) and high levels of total dissolved solids (TDS ~ 1306--2165 mg/L). Concentrations of REEs in groundwater are high as expressed by their Nd con- centrations (0.0086-0.018μg/L). Except for weak heavy REEs (HREE) enrichment relative to light REEs (LREE), the similarity of REE distribution patterns between groundwater and aquifer rock indicate that enrichment of REEs is considered to be controlled by aquifer rock, as well as by their minerals, whereas the fractionation of REEs is controlled by HREE enriched minerals and, to a lesser extent, by inorganic REE complexes. Ce anomalies normalized to Post Archean Average Shale (PAAS) and aquifer rock are weak, which probably reflect the contribution of reduced conditions in combination with pH, rather than a sig- nature of aouifer rock. 展开更多
关键词 Rare earth elements Water-rock interaction Sandstone aquifer Groundwater
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Geochemistry of Neoproterozoic mixosedimentite in northern Anhui and its geological significance
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作者 SUN Linhua GUI Herong CHEN Song 《Global Geology》 2010年第3期128-134,共7页
Major oxides,as well as trace elements (including rare earth elements) compositions have been analyzed for the mixosedimentites from Neoproterozoic Jiayuan Formation in northern Anhui,China. The results show that the ... Major oxides,as well as trace elements (including rare earth elements) compositions have been analyzed for the mixosedimentites from Neoproterozoic Jiayuan Formation in northern Anhui,China. The results show that the concentrations of elements are closely related to the relative proportions of carbonates and terrigenous detritus (varying from 2/3 to 1/9 based on petrographic study). The ratios between some immobile elements (e.g. La,Th,Zr and Sc) are constant and then can be used as tracers for the discrimination of provenance and tectonic setting of terrigenous detritus. The results indicate that the terrigenous detritus mainly came from the felsic volcanics related to continental arc,with minor contribution from the old basement. Combined with recent research progresses,these mixosedimentites imply that the Neoproterozoic sedimentation in northern Anhui was probably taken place in a back arc basin during the convergence of Rodinia super continent between 1.0 and 0.8 Ga. 展开更多
关键词 PROVENANCE tectonic setting mixosedimentites NEOPROTEROZOIC northern Anhui
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Moxibustion eases chronic inflammatory visceral pain through regulating MEK, ERK and CREB in rats 被引量:13
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作者 Zhi-Yuan Li Yan Huang +9 位作者 Yan-Ting Yang Dan Zhang Yan Zhao Jue Hong Jie Liu Li-Jie Wu Cui-Hong Zhang Huan-Gan Wu Ji Zhang Xiao-Peng Ma 《World Journal of Gastroenterology》 SCIE CAS 2017年第34期6220-6230,共11页
AIM To investigate the effects of herb-partitioned moxibustion(HPM) on phosphorylation of mitogen-activated extracellular signal-regulated kinase(MEK)1, extracellular signal-regulated kinase(ERK)1/2 and c AMP response... AIM To investigate the effects of herb-partitioned moxibustion(HPM) on phosphorylation of mitogen-activated extracellular signal-regulated kinase(MEK)1, extracellular signal-regulated kinase(ERK)1/2 and c AMP response element binding protein(CREB) in spinal cord of rats with chronic inflammatory visceral pain(CIVP), and to explore the central mechanism of HPM in treating CIVP.METHODS Male Sprague-Dawley rats were randomized into normal, model, HPM, sham-HPM, MEK-inhibitor and dimethyl sulfoxide(DMSO) groups. The CIVP model was established using an enema mixture of trinitrobenzene sulfonic acid and ethanol. HPM was applied at bilateral Tianshu(ST25) and Qihai(CV6) acupoints in the HPM group, while in the sham-HPM group, moxa cones and herb cakes were only placed on the same points but not ignited. The MEK-inhibitor and DMSO groups received L5-L6 intrathecal injection of U0126 and 30% DMSO, respectively. Abdominal withdrawal reflex(AWR), mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were applied for the assessment of pain behavior. The colonic tissue was observed under an optical microscope after hematoxylin-eosin staining. Expression of phosphor(p)MEK1, p ERK1/2 and p CREB in rat spinal cord was detected using Western blotting. The levels of MEK, ERK and CREB m RNA in rat spinal cord were detected using real-time polymerase chain reaction. RESULTS Compared with the normal group, the AWR scores were increased significantly(P < 0.01) and the MWT and TWL scores were decreased significantly(P < 0.05) in the model, sham-HPM and DMSO groups. Compared with the model group, the AWR scores were decreased significantly(P < 0.01) and the MWT and TWL scores were increased significantly in the HPM and MEK-inhibitor groups(P < 0.05). Compared with the sham-HPM and DMSO groups, the AWR scores were decreased significantly(P < 0.01) and the MWT and TWL scores were increased significantly(P < 0.05) in the HPM and MEK-inhibitor groups. Compared with the normal group, the expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were increased significantly in the model, sham-HPM and DMSO groups(P < 0.01 or < 0.05). Compared with the model group, the expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were reduced significantly in the HPM and MEK-inhibitor groups(P < 0.01 or < 0.05). Compared with the sham-HPM and DMSO groups, expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were reduced significantly in the HPM and MEK-inhibitor groups(P < 0.01 or < 0.05). CONCLUSION HPM down-regulates protein phosphorylation of MEK1, ERK1/2 and CREB, and m RNA expression of MEK, ERK and CREB, inhibiting activation of the MEK/ERK/CREB signaling pathway in the spinal cord of CIVP rats, which is possibly a critical central mechanism of the analgesic effect of HPM. 展开更多
关键词 Herb-partitioned moxibustion Chronic inflammatory visceral pain Pain behavior ANALGESIA MEK Extracellular signal-regulated kinase c AMP response element binding protein Signaling pathway
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FORMATION OF LARGE-SCALE TECTONIC ELEMENTS FROM THE POSITION OF CENTRIFUGAL-INERTIAL FORCE ACTION
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作者 Molchanov V. I. Paraev V. V. 《Geotectonica et Metallogenia》 2005年第1期13-33,共21页
We describe the earlier unknown, when applied to global tectonics, centrifugal inertial mechanism of lithosphere plate moving under the effect of forces appearing as a result of Earth’s planetary rotation. The mechan... We describe the earlier unknown, when applied to global tectonics, centrifugal inertial mechanism of lithosphere plate moving under the effect of forces appearing as a result of Earth’s planetary rotation. The mechanism stated gives an insight into global tectonics of plates with the indirect participation of emanation streams which, in their turn, are the derivatives of centrifugal and inertial forces of planetary motion. The application of this mechanism provides a logical explanation for the regularities of global tectogenesis including the formation of mountain ridges mainly of submeridional and sublatitudinal strike, and also the drift of continental plates from the east to the west and from the south to the north. The mechanism clarifies the significance of the Arctic and the Antarctic Circles as geodynamic barriers. 展开更多
关键词 formation tectonic element centrifugal-inertial force section
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Trace elements and stable isotopic geochemistry of an Early Cambrian chert-phosphorite unit from the lower Yurtus Formation of the Sugetbrak section in the Tarim Basin 被引量:7
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作者 YAO ChunYan MA DongSheng +2 位作者 DING HaiFeng ZHANG XiaoYong HUANG Hui 《Science China Earth Sciences》 SCIE EI CAS 2014年第3期454-464,共11页
A chert-phosphorite unit from the Sugetbrak section in the Tarim Basin was analyzed for rare earth elements(Ce,Eu),redox sensitive proxies,and carbon isotopic compositions(??13C carb and??13C org)in the lower Yurtus F... A chert-phosphorite unit from the Sugetbrak section in the Tarim Basin was analyzed for rare earth elements(Ce,Eu),redox sensitive proxies,and carbon isotopic compositions(??13C carb and??13C org)in the lower Yurtus Formation of the Early Cambrian period.Redox sensitive element ratios(Th/U,V/Cr,Ni/Co,and V/Sc)were employed to determine the palaeoenvironmental conditions during this period.The ratios indicated that the depositional environment of the chert-phosphorite-black shale unit ranged from suboxic to anoxic.Negative Ce and positive Eu anomalies in the chert-phosphorite assemblages of the studied Yurtus Formation indicated the existence of a redox-stratified ocean,similar to that of South China.Overturn or upward expansion of the deep water-mass probably reached the shallow marine zone after the formation of the Yurtus phosphorites.The characteristics of the negative Ce anomaly may be due to phosphoritic inheritance from the Ce-depleted signature of the overlying water column.Subsequent hydrothermal inputs and reduced detrital supplies of the deep water caused by the upwelling affected certain redox sensitive elements in the sedimentary basin.??13C carb and??13C org negative excursions in the Yurtus chert-phosphorite unit may be related to a transgression phase when episodic basinal upwelling moved12C-and P-rich waters from the pelagic basin floor to the continental shelf.Although carbon isotopic compositions in the Yurtus chert-phosphorite assemblages may have suffered from diagenetic alteration,they can be used to probe diagenetic conditions.Multi-proxy geochemical studies indicated that the??13C carb values of the Yurtus chert-phosphorite assemblages might be considered reflections of a predominantly suboxic environment that was subsequently affected by hydrothermal inputs due to the upwelling. 展开更多
关键词 redox sensitive element ratios carbon isotope sedimentary environment Early Cambrian Tarim Basin
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Geochemical characteristics and geological significance of Cretaceous phonotephrite from the Mid-Pacific Mountains 被引量:1
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作者 Shuangshuang CHEN Jiaqi LIU 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第6期745-764,共20页
Systematic analyses were conducted including the petrographic features, major and trace elements, Sr and Nd isotopic compositions, and mineral structure and compositions of whole rocks. Mid-Pacific Mountain volcanic r... Systematic analyses were conducted including the petrographic features, major and trace elements, Sr and Nd isotopic compositions, and mineral structure and compositions of whole rocks. Mid-Pacific Mountain volcanic rocks are mainly phonotephrite with a porphyritic texture. Phenocrysts are mainly composed of Ca-rich plagioclase, clinopyroxene and nepheline.These volcanic rocks are significantly rich in large-ion lithophile and light rare earth elements, without obvious Eu anomalies(δEu=0.99–1.03), and with relatively enriched^(87) Sr/^(86) Sr(0.703829–0.704313) and^(143) Nd/^(144) Nd isotopic ratios(0.512857–0.512871), suggesting that they have similar but more enriched features than the OIB magmatic source. These volcanic rocks may originate from relatively deep magma source with the existence of spinel-garnet Iherzolites, and have undergone partial melting at a low degree of 1–3%. In addition, The residual Nb-Ta minerals(such as sphene, rutile, perovskite) may remain in the mantle source, and the magma components have undergone metasomatism by carbonate melt/fluid or alkali-rich fluid, causing high contents of incompatible elements and significant loss of Nb, Ta and Ti in these volcanic rocks. There are many similarities between the phonotephrites in the Mid-Pacific Mountain and the volcanic rocks in the Line Islands based on the tectonic settings and the geochemical characteristics. We thus speculate that Site 313 volcanic rocks in the Mid-Pacific Mountain is most likely to be a continuation of the Line Islands. 展开更多
关键词 Phonotephrite OIB-type mantle source Carbonatite metasomatism Line Islands Mid-Pacific Mountain
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Simple and cost-effective methods for precise analysis of trace element abundances in geological materials with ICP-MS 被引量:22
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作者 Shuo Chen Xiaohong Wang +7 位作者 Yaoling Niu Pu Sun Meng Duan Yuanyuan Xiao Pengyuan Guo Hongmei Gong Guodong Wang Qiqi Xue 《Science Bulletin》 SCIE EI CAS CSCD 2017年第4期277-289,共13页
Inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion... Inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion, isobaric interferences and instrumental drift remain obvious problems that must be overcome in order to obtain precise and accurate results, For this reason, we have done many experi- ments and developed a set of simple, cost-effective and practical methods widely applicable for precise and rapid determination of trace element abundances in geological materials using ICP-MS. Commonly used high-pressure digestion technique is indeed effective in decomposing refractory phases, but this inevitably produces fluoride complexes that create new problems. We demonstrate that the fluoride complexes formed during high-pressure digestion can be readily re-dissolved using high-pressure vessel at 190 ℃ for only 2 h for 50 mg sample. In the case of isobaric interferences, although oxide (e.g., MO^+/M^+) and hydroxide (e.g., MO^+/M^+) productivity is variable between runs, the (MO^+/M^+)/(CeO^+/Ce^+) and (MOH^+/M^+)/(CeO^+/Ce^+) ratios remain constant, making isobaric interference correction for all other elements of interest straightforward, for which we provide an easy-to-use off-line procedure. We also show that mass-time-intensity drift curve is smooth as recognized previously, for which the correction can be readily done by analyzing a quality-control (QC) solution and using off-line Excel VBA procedure without internal standards. With these methods, we can produce data in reasonable agreement with rec- ommended values of international rock reference standards with a relative error of 〈8% and precision generally better than 5%. Importantly, compared to the widely used analytical practice, we can effectively save 〉60% of time (e.g., 〈24 h vs. 〉60 h). 展开更多
关键词 Inductively coupled plasma mass spectrometry High-pressure digestion Oxide and hydroxide interferences Instrumental drift Correction methods Trace elements
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