镁橄榄石砂在大型铸钢件中的应用

介绍了镁橄榄石砂在大型铸钢件中的应用情况,为解决大型铸铜件的表面化学黏砂,结合生产实际。提出了将铸件原砂由石英砂改为镁橄榄石砂,并确定出合理配制镁橄榄石砂的工艺,使所生产的大型铸钢件的表面化学黏纱现象得到彻底消除。     

负压薄膜橄榄砂型铸铁件表面光洁度的研究

本文研究用橄榄石砂进行负压薄膜造型时,各种不同工艺因素对铸铁件表面光洁度的影响,试验结果:不同壁厚(5～35mm)的试样,经用光切法显微镜测定,表面不平度为14.0～73.3μm,即国家标准表面光洁度▽5～▽3级;通过计算机计算各影响因素的显著性说明,橄榄石砂粒度分布和涂料的作用最为显著,真空度和浇注温度次之.研究表明,橄榄石砂的化学成分和矿物性能较硅砂优越,用之于铸铁件生产,能提高铸件质量;又由于它不含游离的二氧化硅,兼有减少硅肺公害的特点,所以颇适用于负压薄膜造型.     

铸造常用的特种砂

比较了与普通的石英砂的特点。铸造应用最广的特种砂包括锆英砂、铬矿砂、镁橄榄石砂、铝硅系耐火熟料和其它特种砂。介绍了铸造常用的特种砂的产地、分布、生产过程、产量、特点及其应用,并介绍了铸造常用的特种砂的铸造性能和使用情况。     

添加电熔MgO-ZrO2共晶砂对低MgO-C砖性能的影响

在以电熔镁砂、鳞片石墨为原料、酚醛树脂为结合剂的低碳MgO-C砖中,分别添加10%,15%,20%的电熔MgO-ZrO2共晶砂替代镁砂,经200,1 000,1 500 ℃处理后,对材料的体积密度、显气孔率、耐压强度、线变化率、热膨胀率和抗氧化性进行了检测,并借助XRD研究了试样的物相组成和显微结构.结果表明,随着电熔MgO-ZrO2共晶砂加入量的增加,试样的体积密度逐渐增大,线变化率逐渐减小,耐压强度和抗氧化性均为先增大后减小,试样的热膨胀率逐渐减小,抗热震性得到提高.材料性能的变化主要与电熔MgO-ZrO2共晶砂的体积密度大、热膨胀系数小、氧化锆的相变、镁铝尖晶石和镁橄榄石等物相的生成相关.     

MgO加入量和烧成温度对镁橄榄石材料物相组成和性能的影响

在镁橄榄石细粉中加入不同含量的电熔镁砂,以树酯为结合剂,在不同温度下进行烧成,制备镁橄榄石耐火材料.对烧成制品的物相组成、显气孔率、体积密度和常温耐压强度进行检测,研究不同电熔镁砂含量和烧成温度所制镁橄榄石的物相组成和性能.结果表明,随着镁砂含量的增加,镁橄榄石耐火材料的显气孔率逐渐增大;随着烧成温度的提高,镁橄榄石耐火材料的显气孔率逐步降低,有利于加速其合成.     

西秦岭宕昌好梯新生代火山岩中橄榄石捕虏晶的特征及其地质意义

西秦岭宕昌好梯新生代火山岩中含有少许具有明显环带结构的橄榄石. 这些橄榄石颗粒较大，且常出现裂纹或破碎现象，其中心部分的组成（Mg#为90.4-91.0；［Mg#=100Mg/（Mg+Fe²⁺）］）与火山岩中橄榄岩捕虏体中橄榄石的组成相近，其边缘与火山岩中橄榄石斑晶的组成相近（Mg#为85.5-81.9）；而且，这些橄榄石的CaO含量小于0.1%. 这些特征表明这些具有环带结构的橄榄石是捕虏晶，为地幔橄榄岩的解体矿物. 橄榄石捕虏晶的环带结构是橄榄石与寄主岩浆相互作用的结果. 对比已有的研究资料发现寄主岩浆很可能来源于古老的俯冲蚀变洋壳交代富集的地幔源区. 这些新生代火山岩的形成可能与青藏高原的隆升密切相关.     

人工添加橄榄石促进海洋碳增汇过程

海洋是地球上最大的活跃碳库,其储碳周期远超陆地生态系统碳汇,开发海洋碳汇储碳潜力是实现我国碳中和目标的重要途径。人为加速橄榄石风化被认为是增加海洋碳汇的有效途径之一。该文详细阐述了橄榄石风化促进海洋增汇的原理,沿海增强橄榄石风化的方法,并详细介绍国际上添加橄榄石增汇的Vesta项目,展望了在福建沿海建设橄榄石应用工程的可能性,为实现碳中和目标贡献力量。     

钢包用引流材料的流动性能与烧结性能

基于有关钢包的引流技术,研究了石英质、镁橄榄石质和铬铁矿质引流材料在不同石墨和铬铁矿加入量条件下的流动性能、烧结性能和热膨胀性能.结果表明,石英砂加4%石墨混合物的流动性好;一定量的石英砂、铬铁矿、石墨的混合物可以提高材料的流动性能和获得恰当的烧结性能;加入钾长石粉优化了引流砂的烧结性能和热膨胀性能.     

新疆北山罗东岩体橄榄石特征对岩浆演化和硫化物熔离的指示

 罗东岩体是新疆北山地区沿北山裂谷带的一个典型镁铁质—超镁铁质岩体,研究表明坡北杂岩带与东天山杂岩带的产出时代具有时间上的耦合性,并且其大地构造产出背景与东天山镁铁质—超镁铁质杂岩也具有一定的关系,可能与碰撞背景下幔源物质的上侵有关,并且受到俯冲板片的影响。该岩体具有较完整的岩相分异,包括橄榄岩、辉石岩、辉长岩。镁橄榄石指数Fo值为81~88,属于贵橄榄石,橄榄石具有环带结构,从橄榄石边缘到中心,Mg逐渐升高,说明橄榄石在岩浆演化过程中发生了与残余岩浆的交换反应。通过主量元素反演,得到原始岩浆中w(MgO)=8%、w(FeO)=6%,属于拉斑玄武岩。通过橄榄石的定量模拟计算,显示罗东岩体的橄榄石为正常岩浆演化的产物,橄榄石中Ni的质量分数没有发生明显亏损,这些证据表明岩浆可能没有经历过显著的硫化物熔离作用。     

镁橄榄石合成反应动力学研究

以分析纯氧化镁、高纯熔融石英以及电熔镁砂颗粒为原料,研究了固相法合成镁橄榄石的反应动力学.利用X射线衍射和扫描电子显微镜等手段,研究了合成温度和保温时间对镁橄榄石生成速率的影响,分析了MgO与SiO2的反应机理.根据实验结果,建立了1100~1300℃下MgO与SiO2反应的动力学方程,并求出了表观反应活化能.研究结果表明,随着合成温度的提高和保温时间的延长,镁橄榄石生成率逐渐增加.在反应初期,MgO与SiO2反应生成了镁橄榄石和顽火辉石,在合成反应中后期时Mg2+通过产物层扩散而进一步反应,MgO与SiO2反应合成镁橄榄石的反应过程由Mg2+扩散所控制,反应的表观活化能为(220±20)kJ/mol.     

自密实混凝土配合比的工艺性试验研究

针对寒冷地区的材料特点,应用吉林地区的原材料进行免振捣自密实混凝土的试验研究。以砂率、胶凝材料用量、粉煤灰掺量、水胶比这4个因素做正交试验,选择配合比参数,经过正交试验分析,得出同时满足工作性能和力学性能的自密实混凝土配合比。     

吉林油田花敖泡地区青山口组青一段油藏特征分析

为搞清吉林油田花敖泡地区青一段储量分布情况,为勘探部署工作提供更好的理念依据。通过对花敖泡地区沉积特征、砂岩分布特征、成藏条件、油水分布规律及油气成藏规律的分析,确定了该区砂体及油水分布情况、油藏类型。花敖泡地区在青一段沉积时期主要受西南部沉积体系控制,砂体主要分布在Ⅱ—Ⅳ砂组。油层主要分布于Ⅲ、Ⅳ砂组。本区存在两种油藏,即岩性油藏和断层-岩性油藏。     

长白山地区幔源捕虏体的硫化物相及其演化

长白山地区新生代玄武岩的一些层位广布地幔岩捕虏体,在其橄榄石、辉石等矿物内发现有较多的硫化物相,按产出特征可鉴别出3种类型,即早期硫化物颗粒、硫化物包裹体和裂隙中硫化物。硫化物包裹体可以单相硫化物、硫化物－硅酸盐熔体、CO2－硫化物－硅酸盐熔体形式存在。早期硫化物颗粒以磁黄铁矿为主,并发现有方黄铜矿;硫化物包裹体以镍黄铁矿为主,并有黄铜矿、硫铜铁矿出现;裂隙中硫化物均为镍黄铁矿,并具有比硫化物包裹体高的Ni/Fe和（Fe Ni)／S值。地幔岩中存在自早期硫化物颗粒、硫化物包裹体至裂隙硫化物,Ni/Fe和（Fe Ni)/S比值逐渐增加的规律。这种演化不仅受温度和压力制约,而且受Ni,Fe,Cu的地球化学特性和硫逸度的控制。     

Value enhancement of olivine process dust through air classification

As a result of the production of dry olivine sand products at A/S Olivin's production plant at Åheim in western Norway, an annual quantity of some 20000-30000 t of process dust is produced. The bulk of this material is currently being sold as a slag conditioner at a relatively low price; hence, alternative uses of the process dust are now being sought. Information regarding the chemical composition of the material as a function of particle size facilitates product modifications through exclusion or mixing of individual size fractions. This paper demonstrates how such information can be obtained from air classification experiments when these are combined with chemical analysis of the produced size fractions. The classification and subsequent analysis of the olivine process dust revealed that the finer size fractions had high loss on ignition (LOI) values and were relatively low in MgO when compared with the bulk analysis. Removal of the finer fractions resulted in a remaining coarse product of significantly higher quality. The coarse material could be used as a raw material for further processing; it could be recycled or it could constitute a new product in itself.     

2000—2019年东北三省气溶胶光学厚度的时空分布特征

利用MODIS高时空分辨率(日; 1 km×1 km)气溶胶光学厚度新产品MCD19A2, 研究东北三省2000—2019年气溶胶光学厚度(AOD)的时空分布特征。结果显示, 东北三省近20年来AOD变化不大, 均值为0.23。2003年, 春旱、扬沙和农田秸秆燃烧导致AOD最高(0.38)。AOD从南往北呈递减趋势, 总体上辽宁省>吉林省>黑龙江省。AOD高值区集中在辽中南城市群等人口密集的工业发达地区, 低值区分布在大兴安岭、小兴安岭和长白山脉等山区。AOD具有季节分布特征, 春夏季高, 秋冬季低。研究结果可为气溶胶对大气辐射收支平衡影响的研究以及模拟颗粒物浓度提供基础。     

Hydrous olivine unable to account for conductivity anomaly at the top of the asthenosphere

The oceanic asthenosphere is observed to have high electrical conductivity, which is highly anisotropic in some locations. In the directions parallel and normal to the plate motion, the conductivity is of the order of 10(-1) and 10(-2) S m(-1), respectively, which cannot be explained by the conductivity of anhydrous olivine. But because hydrogen can be incorporated in olivine at mantle pressures, this observation has been attributed to olivine hydration, which might cause anisotropically high conductivity by proton migration. To examine this hypothesis, here we report the effect of water on electrical conductivity and its anisotropy for hydrogen-doped and undoped olivine at 500-1,500 K and 3 GPa. The hydrous olivine has much higher conductivity and lower activation energy than anhydrous olivine in the investigated temperature range. Nevertheless, extrapolation of the experimental results suggests that conductivity of hydrous olivine at the top of the asthenosphere should be nearly isotropic and only of the order of 10(-2) S m(-1). Our data indicate that the hydration of olivine cannot account for the geophysical observations, which instead may be explained by the presence of partial melt elongated in the direction of plate motion.     

松嫩平原西部农田土壤有机质和全氮的空间分布影响因素分析

运用地统计学、GIS和传统统计方法,分析松嫩平原西部吉林省通榆县农田表层土壤有机质和全氮的空间分布,并探讨高程、坡度、土壤类型和人工施肥量等因素对土壤有机质和全氮空间分布的影响.研究结果表明:1)吉林省通榆县农田表层土壤有机质含量西部高,东北和西北部低,而全氮含量为北部高,西南部低;2)不同海拔高度上的土壤有机质和全氮含量变化差异并不显著;3)土壤有机质和全氮含量随着坡度的增大,急剧减少;4)淡黑钙土、栗钙土和草甸土的有机质和全氮含量明显高于风沙土和沼泽土;5)通榆县各乡镇人工施肥量与土壤有机质和全氮空间变异的相关性并不强,说明影响本县土壤有机质和全氮含量的因素以自然环境因素为主.     

清末吉林机器局的筹建与吉林市城市化进程

吉林市是清末吉林省早期城市化发展速度较快的城市之一,而吉林机器局的兴办则是吉林市城市化进程快速运行的重要助推器。本文依据近年新发现的一些档案、报纸材料,从城市史的角度,深入考察吉林机器局筹建的具体过程,进而分析吉林机器局的筹建对近代吉林市城市发展演变所产生的影响。     

Resistance to mantle flow inferred from the electromagnetic strike of the Australian upper mantle

Seismic anisotropy is thought to result from the strain-induced lattice-preferred orientation of mantle minerals, especially olivine, owing to shear waves propagating faster along the a-axis of olivine crystals than along the other axes. This anisotropy results in birefringence, or 'shear-wave splitting', which has been investigated in numerous studies. Although olivine is also anisotropic with respect to electrical conductivity (with the a-axis being most conductive), few studies of the electrical anisotropy of the upper mantle have been undertaken, and these have been limited to relatively shallow depths in the lithospheric upper mantle. Theoretical models of mantle flow have been used to infer that, for progressive simple shear imparted by the motion of an overriding tectonic plate, the a-axes of olivine crystals should align themselves parallel to the direction of plate motion. Here, however, we show that a significant discrepancy exists between the electromagnetic strike of the mantle below Australia and the direction of present-day absolute plate motion. We infer from this discrepancy that the a-axes of olivine crystals are not aligned with the direction of the present-day plate motion of Australia, indicating resistance to deformation of the mantle by plate motion.     

Natural examples of olivine lattice preferred orientation patterns with a flow-normal a-axis maximum

Tectonic plate motion is thought to cause solid-state plastic flow within the underlying upper mantle and accordingly lead to the development of a lattice preferred orientation of the constituent olivine crystals. The mechanical anisotropy that results from such preferred orientation typically produces a direction of maximum seismic wave velocity parallel to the plate motion direction. This has been explained by the existence of an olivine preferred orientation with an 'a-axis' maximum parallel to the induced mantle flow direction. In subduction zones, however, the olivine a axes have been inferred to be arranged roughly perpendicular to plate motion, which has usually been ascribed to localized complex mantle flow patterns. Recent experimental work suggests an alternative explanation: under conditions of high water activity, a 'B-type' olivine preferred orientation may form, with the a-axis maximum perpendicular to the flow direction. Natural examples of such B-type preferred orientation are, however, almost entirely unknown. Here we document widespread B-type olivine preferred orientation patterns from a subduction-type metamorphic belt in southwest Japan and show that these patterns developed in the presence of water. Our discovery implies that mantle flow above subduction zones may be much simpler than has generally been thought.