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针对目前刺参养殖业中面临的问题,系统研究了刺参的基础生物学、组织学,生理生态学和呼吸生理学特征,评估了刺参的养殖容量,优化了养殖模式,以嵊泗列岛为例,系统研究了刺参南移后的存活和生长等特征。研究结果如下: 1.刺参体腔液细胞存在于刺参的体腔中,体腔液细胞行使免疫防御、营养贮存和运输的功能。根据形态和功能上的特征可分为小淋巴细胞、桑葚细胞、吞噬细胞、结晶细胞、纺缍细胞和振动细胞。体腔液细胞的形态和结构与其功能密切相关。不同特征的细胞可能是同一类型体腔液细胞的不同发育阶段。体腔液细胞平均密度为(3.79 ± 0.65)×106 cells /ml-1. 刺参的血淋巴细胞可分为小淋巴细胞、桑葚细胞、吞噬细胞和结晶细胞。刺参体腔液细胞可分为小淋巴细胞、桑葚细胞、吞噬细胞、结晶细胞、纺锤细胞和振动细胞。刺参吞噬细胞的吞噬率与温度呈正相关,并呈现出强烈的凝集现象。 2.刺参的血管、呼吸树、肌细胞和体腔内皮细胞的超微结构复杂,与其功能密切相关。夏眠前后刺参消化道明显萎缩,上皮细胞重吸收现象显著,结果显示组织结构的改变与外界环境相适应。刺参夏眠时体腔液pH和PO2升高,PCO2降低。连续取样对刺参体腔液血气指标没有显著性影响。刺参体腔液的%Extrw和%EwO2与体重呈负相关。 3.刺参的扰动导致底质中有机物含量、TOC、TN、叶绿素和细菌含量降低,刺参粪便中有机物含量高于周围底质,刺参对摄食底质具有选择性。刺参的扰动能增强底质的稳定性,与对照组相比,硫化物含量和氧化还原电位降低。 4.根据水体理化指标变化和自然沉积有机物的供饵力,结合不同温度下大规格刺参对自然生物沉积物的吸收率,计算刺参的养殖容量。浅海典型水域刺参的养殖容量约为109.40 g y-1m-2。 5.前三岛近岛水域底质有机物含量高于离岸深水水域,且粒度较离岸水域细,大多在0.20 mm以下。刺参的放流浓度和参礁的放置深度应选择在5-12m。刺参的放养规格宜为经人工越冬后体长在8-10厘米的参苗,体重超过30克。 6.研究了三种规格的刺参笼养殖存活和生长特征,初步建立了刺参筏式笼养技术。投喂海带,存活率达到83%以上。密度对刺参的生长有着显著的影响,随着实验的进行,放养密度增加,刺参的体重减小。4月后,随着温度的升高和海况的改变,刺参的生长率下降。刺参南移养殖模式的适宜放养密度应控制在3-5头,放养规格应在40g以上,经过5-6个月的生长能达到100g左右。

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本文研究了国际上刚刚兴起的海浪,天文潮及风暴潮耦合数值模式,考虑了天文潮与风暴潮的相互作用对海浪的影响(简称TSW)。研究表明,TSW的影响依不同的时间、地点和风力强弱而不同,在某些时刻和地点,TSW对波高的影响超过1M,对波向的影响达30#deg#。WTS的影响对天文潮与风暴潮耦合水位起调制作用,在风暴发生初期大一些,后期小一些。

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温度跃层是反映海洋温度场的重要物理特性指标,对水下通讯、潜艇活动及渔业养殖、捕捞等有重要影响。本文利用中国科学院海洋研究所“中国海洋科学数据库”在中国近海及西北太平洋(110ºE-140ºE,10ºN-40ºN)的多年历史资料(1930-2002年,510143站次),基于一种改进的温跃层判定方法,分析了该海域温跃层特征量的时空分布状况。同时利用Princeton Ocean Model(POM),对中国近海,特别是东南沿海的水文结构进行了模拟,研究了海洋水文环境对逆温跃层的影响。最后根据历史海温观测资料,利用EOF分解统计技术,提出了一种适于我国近海及毗邻海域,基于现场有限层实测海温数据,快速重构海洋水温垂直结构的统计预报方法,以达到对现场温跃层的快速估计。 历史资料分析结果表明,受太阳辐射和风应力的影响,20°N以北研究海域,温跃层季节变化明显,夏季温跃层最浅、最强,冬季相反,温跃层厚度的相位明显滞后于其他变量,其在春季最薄、秋季最厚。12月份到翌年3月份,渤、黄及东海西岸,呈无跃层结构,西北太平洋部分海域从1月到3月份,也基本无跃层结构。在黄海西和东岸以及台湾海峡附近的浅滩海域,由于风力搅拌和潮混合作用,温跃层出现概率常年较低。夏季,海水层化现象在近海陆架海域得到了加强,陆架海域温跃层强度季节性变化幅度(0.31°C/m)明显大于深水区(约0.05°C/m),而前者温跃层深度和厚度的季节性变化幅度小于后者。20°N以南研究海域,温跃层季节变化不明显。逆温跃层主要出现在冬、春季节(10月-翌年5月)。受长江冲淡水和台湾暖流的影响,东南沿海区域逆温跃层持续时间最长,出现概率最大,而在山东半岛北及东沿岸、朝鲜半岛西及北岸,逆温跃层消长过程似乎和黄海暖流有关。多温跃层结构常年出现于北赤道流及对马暖流区。在黑潮入侵黄、东、南海的区域,多温跃层呈现明显不同的季节变化。在黄海中部,春季多温跃层发生概率高于夏季和秋季,在东海西部,多跃层主要出现在夏季,在南海北部,冬季和春季多温跃层发生概率大于夏季和秋季。这些变化可能主要受海表面温度变化和风力驱动的表层流的影响。 利用Princeton Ocean Model(POM),对中国东南沿海逆温跃层结构进行了模拟,模拟结果显示,长江冲淡水的季节性变化以及夏季转向与实际结果符合较好,基本再现了渤、黄、东海海域主要的环流、温盐场以及逆温跃层的分布特征和季节变化。通过数值实验发现,若无长江、黄河淡水输入,则在整个研究海域基本无逆温跃层出现,因此陆源淡水可能是河口附近逆温跃层出现的基本因素之一。长江以及暖流(黑潮和台湾暖流)流量的增加,均可在不同程度上使逆温跃层出现概率及强度、深度和厚度增加,且暖流的影响更加明显。长江对东南沿海逆温跃层的出现,特别是秋季到冬季初期,有明显的影响,使长江口海域逆温跃层位置偏向东南。暖流对于中国东南沿海的逆温跃层结构,特别是初春时期,有较大影响,使长江口海域的逆温跃层位置向东北偏移。 通过对温跃层长期变化分析得出,黄海冷水团区域,夏季温跃层强度存在3.8年左右的年际变化及18.9年左右的年代际变化,此变化可能主要表现为对当年夏季和前冬东亚地区大气气温的热力响应。东海冷涡区域,夏季温跃层强度存在3.7年的年际变化,在El Nino年为正的强度异常,其可能主要受局地气旋式大气环流变异所影响。谱分析同时表明,该海域夏季温跃层强度还存在33.2年的年代际变化,上世纪70年代中期,温跃层强度由弱转强,而此变化可能与黑潮流量的年代际变化有关。 海洋水温垂直结构的统计预报结果显示,EOF分解的前四个主分量即能够解释原空间点温度距平总方差的95%以上,以海洋表层附近观测资料求解的特征系数推断温度垂直结构分布的结果最稳定。利用东海陆架区、南海深水区和台湾周边海域三个不同区域的实测CTD样本廓线资料,对重构模型的检验结果表明,重构与实测廓线的相关程度超过95%的置信水平。三个区重构与实测温度廓线值的平均误差分别为0.69℃,0.52℃,1.18℃,平均重构廓线误差小于平均气候偏差,统计模式可以很好的估算温度廓线垂直结构。东海陆架海区温度垂直重构廓线与CTD观测廓线获得的温跃层结果对比表明,重构温跃层上界、下界深度和强度的平均绝对误差分别为1.51m、1.36m和0.17℃/m,它们的平均相对误差分别为24.7%、8.9%和22.6%,虽然温跃层深度和强度的平均相对误差较大,但其绝对误差量值较小。而在南海海区,模型重构温跃层上界、下界和强度的平均绝对预报误差分别为4.1m、27.7m和0.007℃/m,它们的平均相对误差分别为16.1%、16.8%和9.5%,重构温跃层各特征值的平均相对误差都在20%以内。虽然南海区温跃层下界深度平均绝对预报误差较大,但相对于温跃层下界深度的空间尺度变化而言(平均温跃层下界深度为168m),平均相对误差仅为16.8%。因此说模型重构的温度廓线可以达到对我国陆架海域、深水区温跃层的较好估算。 基于对历史水文温度廓线观测资料的分析及自主温跃层统计预报模型,研制了实时可利用微机简单、快捷地进行温跃层估算及查询的可视化系统,这是迄今进行大范围海域温跃层统计与实时预报研究的较系统成果。

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Berberine was abstracted from coptis chinensis and its inhibition efficiency on corrosion of mild steel in 1 M H2SO4 was investigated through weight loss experiment, electrochemical techniques and scanning electronic microscope (SEM) with energy disperse spectrometer (EDS). The weight loss results showed that berbefine is an excellent corrosion inhibitor for mild steel immersed in 1M H2SO4. Potentiodynamic curves suggested that berbefine suppressed both cathodic and anodic processes for its concentrations higher than 1.0 x 10(-4) M and mainly cathodic reaction was suppressed for lower concentrations. The Nyquist diagrams of impedance for mild steel in 1 M H2SO4 containing berbefine with different concentrations showed one capacitive loop, and the polarization resistance increased with the inhibitor concentration rising. A good fit to Flory-Huggins isotherm was obtained between surface coverage degree and inhibitor concentration. The surface morphology and EDS analysis for mild steel specimens in sulfuric acid in the absence and presence of the inhibitor also proved the results obtained by the weight loss and electrochemical experiments. The correlation of inhibition effect and molecular structure of berberine was then discussed by quantum chemistry study. (c) 2005 Elsevier B.V. All rights reserved.

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对小嵩草草甸种子库的大小和物种组成及与种子雨、地上植被的关系进行了初步研究。结果表明,返青期和枯黄期小嵩草草甸种子库单位体积(1.0m×1.0m×0.1m)分别有种子nf=10550粒和nk=13815粒,分别由22种和24种植物组成,分属9个科,其中,莎草科,豆科和龙胆科占优势,禾本科所占比例较小,每平方米种子雨nr=8436.4粒,由25种植物组成,分属10个科,莎草科和禾本科所占比例较大,种子库和种子雨在物种组成上有一定的相似性(r=0.7600,P<0.01),二者共有19个种,分别占种子库和种子雨物种总数的82.61和90.48。地上植被与种子库的相似性较小,地上植被中有43.24和51.35的植物分别在返青期和枯黄期种子库中出现,60%的植物出现于种子雨中。在物种分布和优势度上,地上植被与种子雨间一致性较高,但它们与种子库间有一定的分歧。从地上植被到返青期时的种子库,物种多样性降低了1.61,从而说明种子库不仅是地上植被补充更新的源泉之一,而且是维持植物物种多样性的一种机制。图3参13。

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对高寒草甸藏嵩草 (Kobresiatibetica)种群的繁殖对策进行了初步研究 .结果表明 :藏嵩草属寒冷中生密丛短根茎地下芽植物 ,在高寒生境中采用了以营养繁殖为主、有性繁殖为辅的繁殖策略 ,具体体现在以下几个方面 :藏嵩草种子产量nA=2 0 0 .1m-2 ,但种子萌发率较低 ,室内和野外萌发率分别仅有 4%和 2 % ,经氢氧化钠溶液和赤霉素溶液处理后的种子萌发率分别为 1%和 6 .7% ,而剥去种皮后种子萌发率达 47.3% ,所以种皮坚硬是造成种子萌发率低的主要原因 ;进入种子库、保留至返青期且具有活性的种子仅占种子总数的 31.49% ;单位面积上理论实生苗数仅为1.2 6m-2 ,与此相反 ,藏嵩草营养繁殖所形成的新个体数为 10 1.32m2 ,远远多于种子萌发所形成的实生苗数 .此外 ,藏嵩草营养繁殖效力也远高于有性繁殖效力,营养繁殖效力占总繁殖效力的83.46%(167)。

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This paper selected the Taklamakan Desert and the Badain Jaran Desert as the research areas, tested the carbonate content of surface-sand samples of dunes using Eijkelkamp carbonate goniophotometer, and analyzed the spatial-distribution characteristics of carbonate and estimated the carbonate-stock and secondary carbonate-stock in 1m depth of surface sand in the Taklamakan Desert and the Badain Jaran Desert. In addition, the paper test XRD, SEM, TDA, stable carbon isotope and radioactive strontium isotope of lacustrine deposits in the Taklamakan Desert and carbonates, such as kunkar, root canal, lacustrine deposits, sinter and calcrete, in the Badain Jaran Desert. Resting on the achievements by our predecessors, it analyzed the mineral-composition differences of the carbonates, calculated the contents of secondary carbonate and, furthermore, evaluated their potential of sequestration of CO2 in the atmosphere. The overall goal of this study was to increase our understanding of soil carbonate in the context of carbon sequestration in the arid region in China. That is, to advance our understanding about whether or not secondary carbonate in desert is a sink for atmospheric CO2. The following viewpoints were obtained: 1 Carbonate contents of surface-sand samples decend from the south to the north of the Taklamakan Desert. The minimum lies in the south and the maxmum in the mid. Carbonate content of surface-sand of megadunes in the Badain Jaran Desert has low value generally in the dune-crest and the base of slope, and large value in the mid. The average of Carbonate contents of all sorts of collected samples in the same area of the Taklamakan Desert has small diffetences. The average is about 9%. 2 Using carbonate contents as key parameters, calculate the carbon-stock of carbonates in 1m depth of surface sand in the Taklamakan Desert and the Badain Jaran Deser.They are 1.13Pg and 0.19 Pg respectively. There are 0.53Pg and 0.088Pg carbon-stock of secondary-carbonates in 1m depth of surface sand in the Taklamakan Desert and the Badain Jaran Desert. 3 Through testing data from XRD (X-ray diffraction)and TAD ( Thermal Analysis Data), the most significant conclusion derived from is that the main mineral ingredient is calcite in different carbonate substances in arid regions, From the SEM(Scanning electron microscopy ) images, can obtains the information about the micro environment of different carbonate forms in which they can grow. 4 Selected gas by termal cracking and traditional phosphoric acid method, their δ13C show that δ13C is a good parameter to indicate the micro environment in which different secondary carbonate forms. From the δ13C of the same type samples, if the redeposit degree is hard, theδ13C is light, the redeposit degree is weak, the δ13C is heave. and the δ13C of the different type samples, δ13C is mainly controlled by the micro environment in which secondary formed. if the procedure is characterized by redeposit and dissolve of marine facies carbonate, δ13C is heavy, it is characterized by CO2 which produced by plant respiration,δ13C is light. 5 From the δ13C of lacustrine deposit in the different grain size, there exsit certain differences in their micro environment and secondary degree among different grain size in the same grade. 6 The secondary carbonate content of lacustrine deposits in Taklimakan Desert is 47.26%. And those of root canal, sinter, calcrete, kunkar, lacustrine deposit and surface sand in Badain Jaran Desert are 91.74%, 78.46%, 76.26%, 87.87%, 85.37%and 46.49%, respectively. Of different grain size samples, the secondary carbonate contents of coarse fraction (20-63μm), sub-coarse fraction (5-20μm) and fine fraction (<5μm) are 80.10%, 47.2%and 50.07%, respectively. 7 There is no obvious relevance betweenδ13C of secondary carbonate and the content of secondary carbonate,theδ13C of secondary carbonate mainly reflects the parameters of secondary process, the content of secondary carbonate reflects difference of secondary degree.. 8 Silicates potentially supply 3.4 pencent calcium source during forming process of lacustrine deposits in Taklimakan Desert. If calcium source is mainly supplied by goundwater, it can be calculated that about 5.18 %, 6.13%, 5.68%, 5.64 % and 6.82% silicates supply calcium source respectively for root canal, kunkar, lacustrine deposit, calcrete and sinter, during the forming process of different kinds of carbonates in Badain Jaran Desert.

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Located in the Paleozoic uplift along the southern margin of Tu-Ha basin in eastern Xinjiang, the newly discovered Hongshan Cu-Au deposit occurs in the superimposed Mesozoic volcanic basin upon the north section of later Paleozoic Dananhu-Tousuquan accretionary arc. Kalatage Cu-Au orebelt is controlled by NWW-trend faults, and includes Hongshan and Meiling Cu-Au deposits. The host rocks of Hongshan ore district are mainly rhyolitic-dacitic ignimbrites, whereas Cu-Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and granitic porphyry. Mineralization styles are dominantly veinlet-disseminated and veinlet, occasionally stockwork. The mineral association is chalcopyrite, pyrite, bornite, chalcocite and sphalerite. The hydrothermal alteration consists of silicfication, sericitization, alunitization, pyrophylitization, illitization, hydromuscovitization, and chloritization. Hongshan Cu-Au deposit, on the edge of the desert, is one of the driest areas in eastrn Tianshan. Moreover, the highest temperature has been up to 60℃, and the average rainfall receives only 34.1mm/y. The light rainfall and rapid evaporation in the vicinity of this deposit have allowed the formation of a great variety of water-soluble sulfates. Oxidization zone of this deposit lies on the upper part of primary sulfide orebodies appearing with a depth of 50-60m, which is dominant in sulfate minerals. 1. Based on the field observation, the volcanic and sub-volcanic rock composition, hydrothermal alteration, ore structure and mineralization characteristics, this paper proposed that the Hongshan Cu-Au deposit belongs to a transitional type from high-sulfide epithermal to porphyry Cu-Au deposit, which corresponds with the typical HS-epithermal deposit such as Zijinshan Au-Cu deposit in Fujian Province, SE-China. 2. The Hongshan copper-gold deposit was controlled by the tectonic, stratum, magma activity and volcanic apparatus, whereas Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and fine grained pyritization in hydrothermal activity, and Cu mineralization is closely related to quartz porphyry and hydrothermal explosive breccia. 3. Oxidation zone of Hongshan Cu-Au deposit lies on the upper part of primary sulfide orebodies deposit. 23 sulfate minerals were identified in this work. The results of samples XRD and chemical analysis were furthermore confirmed through thermal, infrared spectrum and mössbauer spectrum analysis. Among those, nine minerals as Ferricopiapite, Cuprocopiapite, Rhomboclase, Parabutlerite, Krausite, Yavapaiite, Metasideronatrite Kroehnkite and Paracoquimbite were founded in China for the first time. And Paracoquimbite was secondly reported in the world (first case reported at 1938 in Chile). 4. EPMA analysis shows that Al impurity in crystal lattice is important to polytype formation of paracoquimbite and coquimbite besides stack fault. 5. Compared with Meiling Cu-Au deposit in the same Kalatage ore belt from the characteristics of δ34S of barite, lithofacies, hydrothermal alteration and homogeneous temperature, Hongshan Cu-Au deposit belongs to the same metallogenic system of HS-epithermal type as Meiling Cu-Au deposit. But Hongshan Cu-Au deposit has less extensive alteration and shallower denudation. 6. Sulfur isotope analyses show that δ34S values of pyrites vary in the range of +1.86‰~+5.69‰, with an average of 3.70‰, mostly in the range of +1.86‰~+3.20‰, and δ34Scp<δ34Spy. Therefore ore-forming fluid of porphyry comes from mantle and was contaminated by the earth’s crust. Sulfur isotope has reached balance in ore-forming process. 7. Sulfur isotope analyses show that δ34S values of sulfates vary in the range of +2.15‰~+6.73‰, with an average of +3.74‰, mostly equals as δ34S values of primary sulfides in Hongshan Cu-Au deposit. So supergene sulfates inherit sulfur of primary sulfide. δ34S values are mostly same in different sulfates. As well as pyrite and chalcopyrite, volcanic hot spring and associated native sulfur underground also provide water medium and sulfur during the formation process of sulfate. 8. According to the EPMA of sample chalcopyrite and pyrite in Hongshan Cu-Au, the value of Cu/Ni is 0.98-34.72, mostly close to the value of 5, which shows that Hongshan deposit is a typical volcanogenic magmaic hypothermal deposit. Au and Ag, Zn, Te and Bi are positive correlation, Cu and Hg, Se, Sb are positive correlation, indicates Au and Cu don’t locate in the factor of mineralization of same mineralization groups. The reasons of gold concentration in the oxidation zone are: 1). Change of redox potential (Eh) makes gold to deposit from the liquid of mineralization zone; 2). PH is one of the most factors of gold’s deposition; 3). Soluble complex and colloid of gold can be adsorbed easily. 9. The biotite and hornblende K-Ar isotopic ages from the wall rock-quartz diorite, biotite granite and monzonite granite are 231.99±3.45Ma, 237.97±2.36Ma and 296.53±6.69Ma respectively. The ore-bearing rhyolitic breccia lava contains breccia of the biotite granite which indicates the volcanism and related Cu-Au mineralization occurred later than the granite, possibly in Mesozoic. K-Ar ages of granitoids in Sanya, Baishiquan and Hongliugou area and Molybdenite Re-Os age of Baishan Mo deposit all are in Triassic. Besides late Paleozoic magmatism, igneous magmatic event of Mesozoic was widespread in eastern Tianshan. 10. The K-Ar age dating indicates that the K-Ar age of Voltaite occurred below surface 1m is 56.02±3.98Ma, K-Ar age of Ferricopiapite occurred below surface 1.5m is 8.62±1.12Ma, K-Ar age of Yavapaiite occurred below surface 14 m is 4.07±0.39Ma, and K-Ar age of Voltaite occurred below surface 10 m is 14.73±1.73Ma. So the age interval of oxidation zone of Hongshan copper-golden bed is between 60 -3.38Ma. Oxidization occurred at Caenozoic era (from 65Ma), which can be identified through comparing with different deposits oxidation zone in other countries. The coupling between global tectonic event and climatic change event which occur from Caenozoic era has some effect on epigeosphere system, which can act on the surface of bed oxidation zone similarly. It induces that the age mentioned above coincide with collision of India-Asia and multistage uplifting of Qinhai-Tibet Plateau happened subsequently. Bed oxidation zone is the effect and record of collision and uplifting of Tibet Plateau. The strong chemical weathering of surface accumulation to which was leaded by PETM event occurred Paleocene and Eocene is the reason of Voltaite sharply rises. On the contrary, Ferricopiapite formed due to the global cold weather. The predecessor did much research through biota, isotopes, susceptibility, but this paper try to use different sulfate mineral instead of climatic change. So the research of sulfate minerals not only indicates a great deal of oxidized zone feature, but also the intergrowth of sulfate minerals may be used to trace paleoenviroment and paleoclimate of oxidation zone. 11. Analysis of the information of alteration and mineralization features of four bore cores, induced activity polarization well logging and Eh-4 geophysical section, deep mineralization anomaly objects of Hongshan ore districts shows low resistance, middle and high polarization, measurements of Eh-4 consecutive conductance section show the existing of concealed porphyry ore body deeper than 450m, on the top of and around rock body there are low resistance body ranged from 100-300Ω•m, this area may be the ore-bearing part. In a word, Hongshan Cu-Au deposit deposit is a combine of upper HS-style epithermal Au deposit and deeper porphyry mineralization system. It has great potential to find large HS-style epithermal-porphyry Au-Cu deposits. This paper consists of seven chapters and twenty seven sections. The geological character of deposit is basic condition in this work. Constitute of oxidation zone, research of sulfate mineral, relation between oxidation and primary zone, K-Ar ages of potassic sulfate are key parts of thesis. Genesis of ore deposit is the further expansion of this research. Analysis of ore-controlling factors is the penetration above basic. Analysis of potential is application of exploration.

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碳酸盐岩由于酸不溶物含量极低,在形成风化壳的过程中伴随巨大的体积缩小,形成1m厚的风化壳往往需要消耗原岩十几米至几十米。所以对于岩溶地区风化壳,尤其是厚层红色风化壳的机理研究中,母岩的均一性判别是必要的,是风化壳研究的基础。通过对贵州岩溶地区贵阳花溪、湖潮剖面和黔北遵义市新蒲剖面三个典型的残积风化壳的粒度分析表明,碳酸盐岩风化壳成土母岩的不均一性是客观存在的,从粒度分布特征给予了良好的指示。而不均一母岩上发育的风化壳的地球化学行为,也必然偏离建立在均一母岩前提下的风化壳的正常演化方向。此外,常作为表生环境下物源示踪的惰性元素比

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短半衰期的137Cs具有高放射毒性,而半衰期较长的Pu的化学毒性极强,它们在环境中富集,进而在食物链中迁移,将直接威胁人类健康,国内在Pu和137Cs的分析方法、环境剂量以及湖泊地质等方面已展开了一些研究,但仍处于起步阶段,内容不够系统全面。湖泊和水库是生活饮用水或农用灌溉水源地,与人类生活息息相关,因此研究湖泊中人为放射性核素的污染状况、来源及归宿显得尤为重要;而且湖泊沉积物作为湖泊中大多污染物的最终归宿地,能够有效地保存湖泊区域的污染历史,研究湖泊沉积物有助于认清湖泊污染历史、探明污染机理,为污染现状评价、水质调查及治理提供可靠的基础依据,钚和铯的特殊性质可为环境科学等方面的研究提供关键的沉积年代学基础数据。 本研究在全国范围内选取具有代表性的不同区域分布、湖泊类型、人为扰动状况的湖泊为研究对象,应用基于γ谱的137Cs分析方法和本文建立的针对淡水湖泊沉积物的Pu同位素分析方法,研究了人为放射性核素Pu和137Cs在全国范围内的分布特征、近源传输及在湖泊中的沉积与迁移机理,并探讨了239+240Pu计年方法的有效性。通过上述研究,得到了如下主要结论: 1、建立了基于阴离子交换树脂分离的Pu同位素ICP-SF-MS分析方法,采用AG1-X8树脂分离Pu与杂质元素以及AG MP-1M纯化Pu同位素。高的仪器灵敏度、良好的U去除效率、足够的Pu同位素化学回收率表明该方法能够有效地检测湖泊沉积物样品中的痕量239Pu和240Pu。此外,纯化Pu同位素时,采用HBr洗脱Pu同位素以排除PbCl+对Pu同位素的干扰,因此该方法除了适应239Pu、240Pu分离分析之外,还可为后期分析浓度更低的241Pu提供技术保证。 2、通过分析沉积物岩芯中的239+240Pu沉积通量和137Cs沉积通量、240Pu/239Pu同位素平均比、239+240Pu/137Cs活度平均比及Pu、137Cs在沉积物岩芯中的剖面分布特征发现博斯腾湖有中国核试验基地的人为放射性核素污染,其表现形式为核爆试验产生的可溶性气溶胶颗粒和热核颗粒沉降后再悬浮造成的偶然性污染和源自罗布泊的地表径流引起的普遍性污染。博斯腾湖的Pu同位素结果表明平流层沉降的中国核试验的核碎片的240Pu/239Pu同位素原始比值可能为0.18左右,非常接近全球大气沉降值。苏干湖和双塔水库有源自中国核试验的可溶性气溶胶颗粒经大气沉降后再悬浮造成的人为放射性核素污染,苏干湖中大约有40%左右的137Cs以及27%左右的239+240Pu源自中国核试验,双塔水库中源自中国核试验的239+240Pu和137Cs所占的比例分别为27.1%和30.6%。 3、单一的239+240Pu和137Cs蓄积峰不能完全解析出沉积速率较慢的青海湖是否有源自在罗布泊进行的中国核武器爆炸试验的污染,但1963年全球大气沉降高峰下端的低240Pu/239Pu同位素比值表明青海湖可能有源自始建于1957年的中国原子城的地表径流泄漏或地下渗透泄漏的人为放射性核素污染。 4、西南地区的湖泊中,云南程海部分137Cs可能源于长距离迁移的中国核试验,但明确中国核试验对西南地区的影响还需要中国核试验源Pu和137Cs长距离迁移的信息,如青藏高原湖泊和西川盆地湖泊沉积物中人为放射性核素来源。其它湖泊中人为放射性核素的污染均源于全球大气沉降。 5、火山成因封闭式玛珥湖,在没有人为扰动的条件下,137Cs和239+240Pu主要以微弱的分子扩散迁移,迁移速率不明显,能较好地保持沉积历史;对人为活动比较频繁的浅水湖泊而言,人为活动、强风等恶劣气候以及上层水体和底层水体的交互对流等因素引起的沉积物再悬浮作用加剧了239+240Pu和137Cs主要以分子扩散迁移作用,造成水体寄宿时间短的浅水湖泊中239+240Pu和137Cs的不同步损失,导致239+240Pu和137Cs峰型的无序化。 6、受人为扰动较弱的湖泊中137Cs比活度和239+240Pu比活度成良好的线性相关,表明239+240Pu蓄积峰的信息能够为此类型湖泊沉积物提供有效的近期沉积年代学数据;对受人为扰动比较大的湖泊来说,137Cs和239+240Pu蓄积峰在近期沉积物计年的方面各有优劣,计年数据的可靠性不强;青海湖各沉积物岩芯的沉积物计年结果表明湖泊的沉积物累积率或沉积速度存在区域性差异。

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硒是人体和动物必需的微量元素,摄入过高或过低均可导致不同的健康效应。已有的研究表明,硒的生物有效性不仅与地质环境中的总硒有关,更取决于硒的形态分布。不同形态的硒具有显著差异的地球化学特性,影响着环境中硒的迁移、循环、生物有效性和毒性。渔塘坝是中国唯一发生过人群硒中毒爆发性流行的地区,该地区风化富硒碳质岩和高硒土壤中有机结合态硒可达到总硒的60%以上,而有机结合态硒的进一步研究有助于深入了解硒的分布和生物可利用性,阐明富硒碳质岩风化及其成土过程中硒的生物地球化学次生富集过程与循环机制。本论文利用改进的7步连续化学浸提技术和优化的有机结合态硒提取方案,使用氢化物发生-原子荧光光谱法,研究了恩施表生高硒环境中有机结合态硒的形态分布,得出了以下几点结论: 1. 在硒七步连续提取方案的基础上,对影响硒提取的因素如液固比、提取剂浓度等进行了优化、并对不同结合态(相态)硒提取中的若干问题进行了讨论。研究结果表明,硒的连续化学提取过程中,液固比为20:1到50:1时能够满足不同结合态硒提取的要求;在水浴加热条件下,NaOH浓度0.1M~0.5M时能有效提取有机结合态硒;1M Na2SO3溶液是元素硒的较好提取剂;而对于硫化物/硒化物结合态硒,合适配比的NaOH+H2O2混合液有利于H2Se的完全吸收,500~600mL/min的载气气流能保证其被CrCl2+HCl混合液还原所产生H2Se气体的完全吸收。 2. 利用优化的连续化学浸提方案提取风化富硒碳质岩石和高硒土壤样品的有机结合态硒,进而分离出富里酸硒和胡敏酸硒,并用高压密闭消化-氢化物原子荧光光谱法测定了硒的含量。该方案的回收率为84.4~104.2%,平均回收率为96.1%;有机结合态硒与胡敏酸富里酸硒加和值之间有良好的一致性,线性相关系数为0.999(n=14),斜率为1.0026。而后使用自制的氢化物反应发生和吸收装置进一步分离了与富里酸(胡敏酸)吸附的Se(IV)和强结合的硒,其中分离富里酸硒的回收率为86.3%~107.6%,平均值为97.1%;分离胡敏酸硒的回收率为85.5%~105.9%,平均值为97.9%。表明本论文所采用的实验方案是切实可行的。 3. 风化富硒碳质岩石样品中胡敏酸硒比例较高,所占比例为36.3%~75.8%,平均值为58.1%,但胡敏酸硒并不是占有绝对的优势,且各个样品之间存在较大差异。高硒土壤样品中富里酸硒占有机结合态比例在25.4%~85.0%,除个别样品外,多数样品的富里酸硒所占比例均在70%~80%,表明富里酸硒是渔塘坝土壤有机结合态硒的一种主要存在形式,在适当的条件下(如环境的pH-Eh变化),能够被转化从而被植物吸收利用。并且这种岩石中胡敏酸硒含量高、土壤中富里酸硒含量高的分布特征指示了硒在风化过程中可能的迁移和转化规律。 4. 富里酸硒和胡敏酸硒的形态分析表明,不同岩石样品中各有机结合态硒的形态分布差异较大,分布规律不明显,这可能与岩石样品的风化程度有关;而对于土壤样品,不论是在富里酸还是胡敏酸中,吸附Se(IV)的含量都大于强结合硒,尤其是富里酸中的吸附Se(IV),平均值为83.4%,最高达95.4%。这部分吸附的Se(IV)相对于强结合的富里酸硒更容易被释放,而这也进一步佐证了富里酸硒易于受环境变化(pH-Eh)和倍半氧化物等的影响而转变为生物可利用态硒。 5. 无论是胡敏酸强结合硒(HA-Se)还是富里酸强结合硒(FA-Se)均在有机结合态硒中以一定的比例存在,对这部分硒的研究还仅局限于定量,而其究竟是以何种形态、以何种方式与腐殖质结合尚不清楚。因此,有必要对这部分硒进行进一步研究。

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在开放(P_水1M) 1.8%: 1np = 15.347-7.130 * (1000/T) (2.82M) 5%: 1np = 14.717 - 6.381 * (1000/T) (5.63M) 10%: 1np = 14.270-5.806 * (1000/T) (11.26M) 20%: 1np = 14.580 - 5.831 * (1000/T) (16.9M) 30%: 1np = 14.412 - 5.519 * (1000/T)根据这些等式求出了在不同压力、温度下各种浓度的CaCl_2-H_2O流体的水逸度系数(£)。由于至目前为止在文献中还没有这方面的实验研究报道,因而无法评价这一新方法所获得的数据的准确性。利用求得的£值,在本篇论文中建立起了不同浓度的CaCl_2-H_2O流体影响钙蒙脱石脱水温度的热力学模式:TD' = [T_1*T_D*(ΔH_(tw) + ΔH_(sv)~盐)/[T_1*(ΔG + ΔH_(dn)~水)-T_D~* (ΔH_(av)~水-ΔH_(sv)~盐)在0-1M浓度范围内,可以认为ΔH_(dh)~水≈H_(dh)~盐,等式变为:TD' = (TD*ΔH_(dh))/(ΔG + ΔH_(dh))根据这个模式,能推导出在实验浓度范围内,钙蒙脱石在盐水体系中的脱水温度。通过本次论文的实验研究知道在一般沉积盆地的埋芷条件下,钙蒙脱石矿物不会发生简单的脱水作用。在缺乏K~+和低盐度的环境中,含水相蒙脱石可稳定地存在在一定深度的地壳中因而不可忽略蒙脱石在海洋化学和俯冲带水来源中的作用。在选择处理簇射性废料的回填料(backfill)时,如其它条件相同,则应优先选择钙蒙脱石,而不是蛭石。在石油采矿和勘探工程中,因压力释放所造成的蒙脱石的脱水作用可能是使钻井变大和塌方的可能性原因之一。