72 resultados para NI-CR ALLOY


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针对鞍山大孤山排岩场由大小不一的石砾组成、无任何土壤、保水性能差、植物所需的营养成分极其贫乏、含有限制植物生长的有毒有害物质等特殊的立地条件,以营养成分丰富的城市污泥、粉煤灰等固体废弃物配制的人工土壤做为修复基质,通过室内模拟试验从人工土壤的保水性能、肥力水平和重金属含量及其活动性等方面研究粉煤灰钝化污泥用做无土排岩场植被再建的可行性,并进行了现场验证试验,结果表明: 采用当地城市生活污泥、粉煤灰以及铁矿尾砂为原料进行合理配比的人工土壤具有较好的持水保水性能;而且该人工土壤中有机质和速效氮、磷、钾的含量都极其丰富,处于高肥力水平;人工土壤的重金属含量符合国家农用标准。因此将这种养分含量较高的粉煤灰钝化污泥人工土壤用做无土排岩场生态修复的基质从理论上是可行的。 人工土壤熟化过程中对地下水的潜在影响研究表明:粉煤灰的加入有效抑制了污泥中氮素硝化作用的发生,同时也降低了钝化污泥人工土壤中SO42-、Cl-的浓度;人工土壤溶液中Cd、Pb、Cu、Zn、Ni、Cr、Mn平衡浓度均显著低于水质中重金属含量的毒害临界水平。因此,将该人工土壤用于鞍山大孤山排岩场植被再建,其土壤浸提溶液不会对地下水造成潜在威胁。 现场试验研究表明,钝化污泥人工土壤用做陡坡无土排岩场的修复基质适宜于乔木刺槐的生长,具有较好的植被成活率及生长势,该修复模式用于陡坡无土排岩场植被再建是可行的。

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通过添加不同比例的粉煤灰对城市生活污泥进行钝化,系统的研究了粉煤灰对钝化污泥中金属元素Cd、Pb、Cu、Zn、Ni、Cr、Mn、Fe含量及其有效化的影响。结果表明:粉煤灰对污泥中有效态Cd、Pb、Ni、Cr、Mn、Fe具有钝化作用,其中对Cd和Fe的钝化效果最明显;但对Cu却有促进其向有效态转化的作用;总体上看钝化污泥人工土壤中重金属含量符合国家农用标准,而其中有效态Cd、Pb、Ni、C r的含量均远远低于对植物体造成毒害的临界水平。

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The sorption on humic acid (HA) of metals from an aqueous solution containing Hg(II). Fe(III), Pb, Cu, Al, Ni, Cr(III), Cd, Zn, Co and Mn, was investigated with special emphasis on effects of pH, metal concentration and HA concentration. The sorption efficiency tended to increase with rise in pH, decrease in metal concentration and increase in HA concentration of the equilibrating solution. At pH 2.4. the order of sorption was: Hg Fe Pb Cu=Al Ni Cr=Zn=Cd=Co=Mn. At pH 3.7. the order was: Hg and Fe were always most readily removed, while Co and Mn were sorbed least readily. There were indications of competition for active sites (CO2H and phenolic OH groups) on the HA between the different metals. We were unable to find correlations between the affinities of the eleven metals to sorb on HA and their atomic weights, atomic numbers, valencies, and crystal and hydrated ionic radii. The sorption of the eleven metals on the HA could be described by the equation Full-size image (1K), where Y = % metal removed by HA; X = mgHA; and A and B are empirical constants

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本文研究了火焰原子吸收,石墨炉原子吸收,结合基体改进剂和平台技术,测定了人参中Pb、Ca、Co、Ni、Cr、Ba、K、Na、Cd、Mg、Fe、Cu、Zu、Mn、Sr等十五个微量元素,结果满意。

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本文通过对冲绳海槽北端和南部两个海区沉积物样品的粒度、矿物和元素组成与分布特征的研究,探讨了冲绳海槽沉积物的来源,给出了一定元素组合的物源意义。通过对冲绳海槽两个柱状沉积物的粒度、矿物、元素在地层中的分布特征的研究,结合浮游有孔虫氧同位素地层划分,探讨了冲绳海槽晚第四纪沉积记录的古环境意义。 冲绳海槽陆架和陆坡沉积物明显具有陆架残留沉积的特征,沉积物主要由陆源碎屑矿物、生物碎屑、粘土矿物和少量自生矿物组成。在冲绳海槽北端,陆架和陆坡砂质区沉积物的主要来源是冰期低海面时古黄河的残留沉积,在现代沉积环境下受到海洋生物和自生沉积作用的改造;济州岛南部的细粒沉积区的物源主要是周围陆架残留沉积,在黄海暖流和黄海沿岸流的综合作用下,残留沉积中的细粒组分再沉积形成的。冲绳海槽北端海槽区沉积物主要是火山活动的产物,火山玻璃和火山型的辉石、紫苏辉石和磁铁矿明显富集。冲绳海槽南部沉积物的主要物源是长江沉积物,此外还有大量的海相生物沉积和自生沉积。对元素分布特征的研究表明,冲绳海槽陆架区富含陆源粗碎屑组分SiO_2和生源碎屑组分CaO和Sr,生物沉积对陆源沉积明显具有稀释作用。陆坡区由于受黑潮暖流的影响,往往富集Fe_2O_3和P_2O_5。在海槽区,陆源细粒组分以及与细粒组分相关的元素A1_2O_3、K_2O、Cu、Zn、Co、Ni和Cr等明显富集。利用R型因子分析的方法确定了两个研究区元素组合,结合沉积物的矿物组成给出不同元素组合的物源意义。对冲绳海槽北部(Y127孔)和南部(E017孔)两个柱状沉积物的浮游由孔虫的δ~(18)O进行了分析,将其与本区具有高分辨率的柱状样氧同位素曲线对比进行,结果表明,δ~(18)O值较敏感地记录了冲绳海槽晚第四纪以来的古环境变化。δ~(18)O的高值往往与冷期相对应,δ~(18)O的低值与暖期相对应。冲绳海槽在12ka BP左右开始了逐渐转暖的过程,在10ka BP左右(YD事件)发生了短暂的降温过程,但降温幅度很小。根据沉积物化学组成在地层中的变化规律,大部分元素较敏感地记录了全新世气候转暖事件,但是对于千年尺度的YD事件,多数元素对此没有明显的响应。冲绳海槽火山活动对沉积物的组成和沉积环境的塑造起到了至关重要的作用。根据氧同位素地层划分,在冲绳海槽北部12ka BP曾有火山活动的纪录,距今约8ka BP以来,冲绳海槽有两次较大规模火山活动的记录。火山活动往往会在短期引起气候的变冷,从而造成海区生态环境的破坏,生物沉积作用减弱。但从长期变化来看,可能是气候变暖的因素之一。火山层的主要特征为沉积物主要由粉砂组成,平均粒径明显高于周围层位,在矿物组成上表现为蒙皂石、火山玻璃和火山型的辉石、紫苏辉石和磁铁矿的含量较高,在化学组成上表现为Na_2O与Zr的同高于周围层位,而陆源性较强的元素TFe_2O_3和K_2O,以及生源组分CaCO_3和Sr的含量普遍低于周围非火山层。

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对传统藏药材波棱瓜中12种微量元素进行了分析。结果显示,在波棱瓜中人体必需微量元素Cu、Fe、Zn、Mn、Co、Ni、Cr、Se等含量较高;对西藏地区不同产地的波棱瓜中的微量元素含量作比较,有极显著差异。提示在选用药材时,应重视其产地。

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测定了胜利油田惠民凹陷14件辉绿岩的过渡元素(Sc、Ti、Cr、Mn、Fe、Ni、Cu和Zn)含量。结果显示岩石中Cr和Ni含量具有很宽的范围(分别为76.9×10^-6~1049×10^-6和56.7×10^-6~495×10^-6),样品商745.2出现异常高的Cr和Ni含量,分别为8718×10^-6和4530×10^-6;Cu和Zn含量高且变化范围大,半数以上样品的Cu和Zn含量分别大于1000×10^-6(1082×10^-6~8111×10^-6)和500×10^-6(634×10^-6~2198×10^-6)。分析认为,本区辉绿岩Cr和Ni含量变化范围宽与岩浆结晶分异作用有关,具异常高Cr和Ni含量样品可能为岩浆演化相对后期,有大量铬铁矿结晶的产物;岩石富集Cu和Zn可能与岩浆上升过程中遭受地壳物质混染作用有关.

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近年来铜、锌同位素地球化学研究已经进入了快速发展时期。作为新兴的同位素技术手段,铜锌同位素工具已普遍应用于地球化学、矿床学、古海洋学和生物学等多种领域,然而铜、锌同位素在湖泊生态系统中的研究却相对较少。湖泊生态系统中,重金属的迁移、循环与转化一直是地球科学家们关注的焦点,但研究手段仅局限于含量与形态的测定。因此本论文旨在通过对湖泊生态系统中铜、锌同位素的研究,揭示影响铜、锌同位素组成的主要因素,为铜、锌同位素成为湖泊系统中新的重金属示踪工具奠定基础。 本论文通过一系列条件实验,确定了用于MC-ICP-MS测定环境样品中铜、锌同位素时最佳的化学分离条件。随后选取红枫湖和阿哈湖为主要研究对象,用此实验流程对湖泊水体及其主要支流悬浮物中的铜、锌同位素的季节及剖面变化进行了初步研究。除此之外,对水体中重金属如Cu、Zn、Mn、Ni、Co、Cr、Cd和Pb的形态分布特征及物质循环进行了研究。主要得出以下几点认识: 1、环境样品中铜锌的最佳分离条件是,采用AG MP-1(100-200目)阴离子交换树脂,分别以7 mol/L HCl + 0.001% H2O2,2 mol/L HCl+ 0.001% H2O2,0.5 mol/L HNO3作为淋洗液,并分别在适当的体积接收淋洗液,可以有效地分离沉积物、植物和悬浮物等样品中的铜和锌。化学分离过程中回收率接近100%,同位素比值的变化均在误差范围以内。 2、红枫湖、阿哈湖水体及主要支流悬浮物和红枫湖生物样品中的δ65Cu分布范围为-2.64‰~1.11‰,可达到3.75‰的变化。红枫湖夏季水体悬浮物的δ65Cu变化为-0.08‰~0.25‰,入湖河流水体悬浮物δ65Cu的变化范围为0.13‰~ 1.11‰;阿哈湖夏季水体悬浮物δ65Cu的变化范围为-0.62‰~0.37‰,入湖河流水体悬浮物δ65Cu的变化范围为-1.08‰~0.60‰。两湖冬季水体悬浮物的δ65Cu值均较负。红枫湖生物样品中δ65Cu较负(-1.54‰~ 0.03‰)。 红枫湖水体悬浮物中δ65Cu的随水深的变化趋势主要受到藻类吸收作用的控制,而阿哈湖δ65Cu的随水深的变化趋势主要受到其物源的控制。说明在贫营养化湖泊中,铜同位素组成可以示踪物源;而在富营养化湖泊中,铜同位素组成则可以示踪生物活动。同时水温的垂直变化也可能是其影响因素之一。 3、红枫湖水体及其主要支流水体悬浮物中的δ66Zn变化范围分别为-0.29‰~0.26‰和-0.04‰~0.48‰,阿哈湖水体及其主要支流水体悬浮物中的δ66Zn变化范围分别为-0.18‰~0.27‰和-0.17‰~0.46‰,均表现出支流中的锌同位素组成较重的趋势。而生物样品中的δ66Zn变化范围较大,为-0.35‰~0.57‰。说明湖泊生态系统中各端元的锌同位素组成存在明显差异。 红枫湖夏季δ66Zn随着湖水深度的变化,与Chla(叶绿素)呈极显著的正相关(R=0.97)。说明锌同位素组成与藻类生物量有一定的响应关系,主要是藻类对锌的有机吸附或是吸收过程改变了锌同位素组成。阿哈湖的锌同位素组成主要受到其源区的控制作用,从而可利用锌同位素示踪源区;此外,红枫湖和阿哈湖悬浮物中的锌同位素比值均表现出夏季小于冬季,说明大气的干湿沉降可能是一个较负的锌同位素源。生物样品中的δ66Zn变化范围较大,说明由于生物作用过程导致的锌同位素分馏大于非生物过程。 4、红枫湖重金属Mn、Ni、Co、Cr、Cd和Pb的含量在南湖高于北湖,主要是羊昌湖的输入所导致;重金属入湖通量的季节性变化,直接导致了重金属含量的季节性变化。沉积物-水界面在冬夏季节,由于“富氧”和“贫氧”状态的改变,导致了溶解态Mn、Ni和Cr的季节性变化;水粒相互作用过程中,溶解有机碳(DOC)、氧化铁胶体、氧化锰胶体和水生藻类的生长繁殖,影响了重金属不同结合形态的变化。

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双泉金矿床是地质工作者最近在东准噶尔地区金矿勘探中的一个新突破,地质研究和勘探程度低导致其成因还不清楚。本文通过对双泉金矿床的控矿特征、矿石矿物组成和结构构造、不同矿化阶段的矿物组合及变形特征、矿石稀土元素、氢氧同位素地球化学特征等方面的研究,探讨了双泉金矿床地质地球化学特征及成矿时代、成矿流体、成矿物质来源等,提出了该矿床的矿床成因,取得如下认识: 双泉金矿床产于下石炭统南明水组地层中,并受控于清水-苏吉泉韧性剪切带。矿石中金矿物主要以显微 (0.2mm~0.2μm)和次显微 (<0.2μm)的裂隙金、晶隙金等形式存在。矿化阶段划分为三阶段,第Ⅰ阶段黄铁矿-毒砂,第Ⅱ阶段金-石英-毒砂-黄铁矿为主要矿化阶段,第Ⅲ阶段矿化弱。利用金矿化相关的热液矿物稳定范围和毒砂的主要成分含量,通过相图得出第Ⅰ和第Ⅱ阶段温度范围分别为330~450℃和300~430℃。对矿石及近矿围岩亲硫元素组合的相关性分析和R类聚类分析得出成矿元素组合为Au-Ag-As-Sb。 卡拉麦里强应变构造带基本控制了金矿带的分布,而其中韧-脆性剪切部位控制了双泉金矿床、矿脉、矿体的产出。韧性剪切带的后两期走滑脆-韧性、脆性剪切变形控制了第Ⅰ、Ⅱ矿化阶段的金矿化。最早于中石炭世开始的区域走滑脆-韧性变形和区域最新赋矿地层主要为石炭系大致限定了双泉金矿床成矿时代为晚石炭世。 双泉金矿床成矿流体的δD为-86~-99(‰),第Ⅰ、Ⅱ矿化阶段的δ18O值随温度降低而降低,根据水岩反应模拟计算得出初始水为变质水。两种矿石稀土元素球粒陨石配分模式呈右缓倾斜型,轻重稀土属弱分离型,δEu弱负异常,与矿区围岩(南明水组地层)基本一致。矿石轻重稀土分异程度介于围岩与蛇绿岩之间,以及热液中有大量与镁铁质、超镁铁质有关的Co、Ni、Cr、Zr、V 等组份,显示成矿流体对蛇绿岩的淋滤迁移和对围岩的叠加改造。这些反映了成矿物质来源与蛇绿岩体与围岩变质有关。 双泉金矿床形成于晚石炭世,是与韧性剪切带有关的,中高温的变质热液型金矿床。

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The laser-solidified microstructural and compositional characterization and phase evolution during tempering at 963 K were investigated using an analytical transmission electron microscope with energy dispersive X-ray analysis. The cladded alloy, a powder mixture of Fe, Cr, W, Ni, and C with a weight ratio of 10:5:1:1:1, was processed with a 3 kW continuous wave CO2 laser. The processing parameters were 16 mm/s beam scanning speed, 3 mm beam diameter. 2 kW laser power, and 0.3 g/s feed rate. The coating was metallurgically bonded to the substrate, with a maximum thickness of 730 mu m, a microhardness of about 860 Hv and a volumetric dilution ratio of about 6%. Microanalyses revealed that the cladded coating possessed the hypoeutectic microstructure comprising the primary dendritic gamma-austenite and interdendritic eutectic consisted of gamma-austenite and M7C3 carbide. The gamma-austenite was a non-equilibrium phase with extended solid solution of alloying elements and a great deal of defect structures, i.e. a high density of dislocations, twins, and stacking faults existed in gamma phase. During high temperature aging, in situ carbide transformation occurred of M7C3 to M23C6 and M6C. The precipitation of M23C6, MC and M2C carbides from austenite was also observed.

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Coatings of TiCp reinforced composite have been produced by laser cladding. Two kinds of coating with different TiCp origins were investigated, i.e. undissolved TiCp and in situ TiCp. For undissolved TiCp, epitaxial growth of TiC, precipitation of CrB, and a chemical reaction occur at phase interfaces, and nanoindentation loading curves show pop in marks caused by the plastic deformation associated with crack formation or debonding of TiCp from the matrix. As for in situ TiCp, no pop in mark appears. Meanwhile, in situ TiCp produces hardness and elastic modulus values that are higher than those produced by the coating that contains undissolved TiCp.

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本文以对热工模具进行失效分析的基础上,利用激光熔覆技术,在5CrMnMo基础上设计并制备强韧兼备的抗高温磨损涂层。

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Titanium carbide particle (TiCp) reinforced Ni alloy composite coatings were synthesized by laser cladding using a cw 3 kW CO2 laser. Two kinds of coatings were present in terms of TiCp origins, i.e. undissolved and in situ reacted TiCp, respectively. The former came from the TiCp pre-coated on the sample, whereas the latter from in situ reaction between titanium and graphite in the molten pool during laser irradiation. Conventional and high-resolution transmission electron microscope observations showed the epitaxial growth of TiC, the precipitation of CrB, and the chemical reaction between Ti and B elements around phase interfaces of undissolved TiCp. The hardness, H, and elastic modulus, E, were measured by nanoindentation of the matrix near the TiCp interface. For undissolved TiCp, the loading curve revealed pop-in phenomena caused by the plastic deformation of the crack formation or debounding of TiCp from the matrix. As for in situ generated TiCp, no pop-in mark appears. On the other hand, in situ reacted TiCp led to much higher hardness and modulus than that in the case of undissolved TiCp. The coating reinforced by in situ generated TiCp displayed the highest impact wear resistance at both low and high impact conditions, as compared with coatings with undissolved TiCp and without TiCp. The impact wear resistance of the coating reinforced by undissolved TiCp increases at a low impact work but decreases at a high impact work, as compared with the single Ni alloy coating. The degree of wear for the composite coating depends primarily on the debonding removal of TiCp.

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The rapidly solidified microstructural and compositional features, the precipitation and transformation of carbides during tempering, and the impact wear resistance of an iron-based alloy coating prepared by laser cladding are investigated. The clad coating alloy, a powder mixture of Fe, Cr, W, Ni, and C with a weight ratio of 10:5:1.1.1, is processed using a continuous wave CO, laser. Microstructural studies demonstrate that the coating possesses the hypoeutectic microstructure comprising the primary dendritic gamma-austenite and interdendritic eutectic consisting of gamma-austenite and M7C3 carbides. gamma-Austenite is a non-equilibrium phase with an extended solid solution of alloying elements. During high temperature tempering at 963 K for 1 h, the precipitation of M23C6, MC and M2C carbides in austenite and in situ carbide transformation of M7C3 to M23C6 and M7C3 to M6C respectively are observed. In addition, the microstructure of the laser-clad coating reveals an evident secondary hardening and a superior impact wear resistance.