首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
珠江广州河段不同粒径沉积物中多氯联苯(PCBs)的分布特征   总被引:5,自引:1,他引:5  
采用湿分法分别将采自珠江广州河段芳村和黄埔水域的沉积物样品分成5个粒径的组分,并测定各组分中多氯联苯(PCBs)、矿物组成、总有机碳(TOC)和碳黑的含量。结果表明,有机质类型是控制多氯联苯在不同粒径组分中的分布特征和富集能力的主要因素。不同粒径组分对含不同氯原子数PCB同系物的富集能力也受有机质类型的影响。在本实验中,含煤屑和焦碳的粒径组分对含有较多氯原子(≥4)PCB同系物的富集能力较强,而含无定型有机质的粒径组分对含较少(2~3)氯原子PCB同系物的富集能力较强。  相似文献   

2.
泥质烃源岩密度分级分离与有机碳分配   总被引:4,自引:0,他引:4  
选取东营凹陷第三系11 块泥质烃源岩样品,粉碎后按小于1.6 g/cm3,1.6~2.2 g/cm3 和大于2.2 g/cm3 的密度,分离成1,2,3 三个组分,希望可以把烃源岩中游离的有机质、无机矿物与有机黏土复合体分别提取出来。对各组分进行质量、有机碳及扫描电镜分析,探讨不同密度组分中有机质赋存形式及有机碳分配方式的差异性。密度分组后各组分的质量、有机碳量回收率基本上达到100%,表明密度分离方法可信,且对烃源岩的破坏较弱。通过扫描电镜观察发现,1 组分中存在大量的生物碎屑有机质,经盐酸处理后,有机质颗粒表面干净,而2,3 组分中只见有大量的矿物颗粒,但能谱分析显示了C 元素的存在。这些特征表明1 组分为生物碎屑有机质,而2,3 组分中有机质与无机矿物相混合。有机碳分析表明,1 组分有机碳含量平均高达14.24%,但其仅占全岩有机碳量的1.11%;2,3 组分中有机碳含量分别为3.26%,2.77%,两者占全岩有机碳量的90% 以上。由此看来与无机矿物相结合是烃源岩中有机质较为重要的赋存方式,这部分有机质对全岩生烃量的贡献不容忽视。  相似文献   

3.
河流沉积物多环芳烃标准样品的制备与定值   总被引:2,自引:1,他引:2  
多环芳烃环境标准样品是保证多环芳烃环境监测和污染调查数据可靠性以及不同实验室间分析数据可比性必不可少的计量工具。美国NIST、欧盟IRMM、英国LGC等研究机构已有沉积物多环芳烃环境标准样品,但浓度水平大部分集中在mg/kg浓度水平,与我国当前的污染水平存在一定差距,难以满足痕量分析(μg/kg)质量保证与质量控制的要求。而我国受天然基体标准样品制备技术和定值分析技术的制约,尚没有研制沉积物多环芳烃环境标准样品。本文研制了适合我国多环芳烃环境监测和科学研究需要的河流沉积物标准样品。沉积物样品采集自松花江哈尔滨段流域,经过自然阴干、研磨、筛分、混匀和灭菌等加工处理,分层随机抽取15瓶样品对16种多环芳烃进行均匀性研究,结果表明样品均匀性良好。在30℃避光保存条件下,采用线性模型进行稳定性研究,标准样品在16个月稳定性检验期间未发现不稳定变化趋势。11家实验室对该河流沉积物标准样品采用气相色谱-质谱法和液相色谱法进行联合定值,经统计分析处理评定出14种多环芳烃的标准值和不确定度,并给出2种多环芳烃的参考值,特性量值在6.9~158 μg/kg之间,不确定度在1.5~25 μg/kg之间,可以满足多环芳烃痕量分析质量保证与质量控制的要求。该标准样品被批准为国家标准样品,填补了国内此类标准样品和标准物质空白,已成功应用于土壤和沉积物样品中多环芳烃的监测,可为进一步开展有机污染物环境基体标准样品研制提供参考和借鉴。  相似文献   

4.
泥质沉积物颗粒分级及其有机质富集的差异性   总被引:12,自引:0,他引:12  
在泥质沉积物颗粒分级的基础上,用显微镜检、XRD和色谱分析等手段获取有机质和无机矿物的特征,探讨二者间的相互关系以及有机质富集的差异性。沉积物偏粗粒级中主要富集的是颗粒有机质,有机碳含量高,C29色谱峰显著;偏细粒级中主要富集的是可溶有机质,有机碳和氯仿沥青A含量均高,C17色谱峰显著,呈现出有机质向粗和细两个端元富集的特点。粗粒级中无机矿物是化学性质稳定的长石和石英等碎屑颗粒;细粒级中是具有较强的化学活性的粘土矿物。因此,在粗粒级中有机质是通过颗粒有机质与矿物颗粒相互共生而富集;在细粒级中有机质是通过可溶有机质与粘土矿物相互结合形成复合体而富集,这反映了不同类型有机质富集机制的差异,会对有机质的保存和演化以及有机质生烃和碳循环过程产生影响,应引起高度重视。  相似文献   

5.
通过对长江口、杭州湾、舟山海域及东海陆架4个海区表层沉积物样品的粒度敏感组分分析,发现东海陆架与长江口具有相似的三级组分物质组成,杭州湾与舟山海域具有相似的两级组分物质组成.综合4个区域粒级组分分布特征,采用湿分法将4个海域表层沉积物样品分成6个粒级:<0.004 mm,0.004~0.025 mm,0.025~0.063 mm,0.063~0.125 mm,0.125~0.250 mm和>0.250 mm,分别提取各级组分和全样进行有机碳及同位素测试.定量分析各级组分有机碳含量、来源及物质组分,除杭州湾海域粗粒级外,基本上<0.004 mm的粘土组分有机碳含量最高;富集在杭州湾海域粗颗粒中的有机质主要来源于陆源植物碎屑.沉积物颗粒大小、物质组成类型是不同粒级有机质富集的主要控制因素.  相似文献   

6.
南岭山地湖泊多环芳烃的大气沉降历史记录   总被引:1,自引:0,他引:1  
高大山脉对大气环流具有阻挡或屏障作用.通过分析测定南岭山地湖泊沉积物中多环芳烃(PAHs)的垂直分布,结合210Pb定年,探讨了大气PAHs污染在南岭山地的沉积历史.结果显示,沉积物中的PAHs主要以低环数化合物为主,其中尤以菲的含量为最高.在剖面深度0~28 cm范围内,总多环芳烃的含量范围为86~778 ng/g.自1970年开始,PAHs含量持续增加,其中20世纪80、90年代中后期PAHs含量略有降低;在2000年后,沉积柱中的PAHs含量呈急剧增加之势态.多环芳烃在大气迁移过程中发生了组成分异,沉积物中相对富集轻组分(低环数)PAHs,与颗粒物结合的大气干湿沉降是PAHs向偏远山地积的主要途径.  相似文献   

7.
广州市空气颗粒物中烃类物质的粒径分布   总被引:13,自引:1,他引:12  
用 Andersen六段分级大流量采样器 (粒径为 : 10~ 7.2 μ m, 7.2~ 3.0 μ m, 3.0~ 1.5 μ m, 1.5~ 0.95 μ m, 0.95~ 0.49 μ m, ≤ 0.49 μ m)采集了广州市荔湾区 4个季度的大气颗粒物样品 , 用气相色谱 (GC)定量分析了其中的正构烷烃 (n-alkanes)组分,用气相色谱-质谱 (GC-MS)定量分析了其中的多环芳烃 (PAHs)组分. CPI2(代表石油成因的碳优势指数 )、 CPI3(代表生物成因的碳优势指数 ) 和 Wax(植物蜡含量 )表明了石油成因的烷烃倾向于富集在细颗粒物上,而生物成因的烷烃倾向于富集在粗颗粒物上.正构烷烃和低相对分子质量多环芳烃表现出双峰模型分布,高相对分子质量多环芳烃呈现单峰模型分布,仅在细颗粒段有一峰值.烷烃和芳烃秋冬季的 MMDs(质量中值直径 )比春夏季的大.在高温季节化合物优先富集在细颗粒物上,而在低温季节则向粗的颗粒物方向偏移.  相似文献   

8.
<正>泥质沉积物(岩)在现代及古代地层都广泛发育,且富集有机质,因而,开展有机-无机相互作用研究对于认识泥质沉积物(岩)沉积过程、有机质富集过程和演化以及油气的勘探开发都具有重要的意义。泥质沉积物(岩)由无机矿物和有机质组成。无机矿物包括碎屑(石英和长石等)、黏土矿物(蒙脱石和伊利石等)、非黏土矿物(氧化物及方解石和白云石等);碎屑颗粒具有较强的惰性,而黏土矿物和氧化物等都含有电荷及较强的化学活性,不同类型矿物的性质差异较大,具有较完善的演化系列。有机质来自于生物  相似文献   

9.
用5%的次氯酸纳从地表沉积物中萃取有机结合金是可行的。对于有机质含量高的湖泊和河流沉积,从有机相中金的回收率接近于定量分析。对于有机质含量低的河流沉积和土壤,由于释放的金被样品的无机组分吸附使金的回收复杂化。对于这些物质有机结合金的回收率低于70%是可能的。对含金53.4ppb的河流沉积物取10克样品时,此方法的精确度约为6%。当用5克河流沉积物样品时约为14%。所有试验获得的结果表明,沉积物和土壤中的金多以有机结合金的形式存在。  相似文献   

10.
本文测定了柯西河流域中尼跨境河段23个河床表层沉积物样品的矿物组分及微量元素含量。结果表明,上、下游沉积物中长石/石英比分别为0.55和0.37,碳酸盐矿物分别以方解石(12%)和白云石(3%)为主,反映上游化学风化强度小于下游;上下游微量元素Zr、Hf、Cs、Li的分布差异与源岩及河流分选作用有关;与其他发源于青藏高原的河流相比,科西河沉积物中∑REE含量总体较高,主要受源区重矿物影响,其中上游∑REE低于下游,与河流分选造成的重矿物分布有关;LREE明显富集及δEu负异常(0.3~0.59)指示沉积物为长英质物源,结合微量元素图解和富集因子分析表明沉积物主要来源于花岗片麻岩,受人为影响较小。  相似文献   

11.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。  相似文献   

12.
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.  相似文献   

13.
郯庐断裂南段研究进展与断裂性质讨论   总被引:13,自引:3,他引:13  
据1:5万区域地质调查和专题研究资料,就郯庐断裂带是否南延与消失的原因,其与大别—苏鲁造山带交截形成的假位错效应,以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上,讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。  相似文献   

14.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

15.
某高速公路下伏煤矿采空区稳定性分析   总被引:10,自引:0,他引:10  
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。   相似文献   

16.
塘口水电站大坝基础座落在断层和裂隙较发育的龟裂纹灰岩上,岩体完整性差、透水性强,多年运行后,大坝灌浆廊道和排水廊道出现多处集中性漏水,为确保大坝安全和电站正常发电,根据渗漏性质和成因,采用对灌浆廊道补充帷幕灌浆,对排水廊道进行固结+帷幕+回填灌浆。通过灌浆处理后,效果良好,表明灌浆工程有效的将导致坝基渗漏的上下游的裂隙通道封闭,并顺利的经受了随后的汛期洪水考验,大坝安全得到保障。  相似文献   

17.
The Global Stratotype Section and Point (GSSP) for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy (SSS) proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy (ICS). The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob's Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.  相似文献   

18.
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix.  相似文献   

19.
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.  相似文献   

20.
正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号