烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

具有良好可再生性的新型二氧化硅磁性氧化石墨烯纳米复合材料

Graphene oxide (GO) wrapped Fe₃O₄ nanoparticles (NPs) were prepared by coating the Fe₃O₄ NPs with a SiO₂ layer, and then modifying by amino groups, which interact with the GO nanosheets to form covalent bonding. The SiO₂ coating layer plays a key role in integrating the magnetic nanoparticles with the GO nanosheets. The effect of the amount of SiO₂ on the morphology, structure, adsorption, and regenerability of the composites was studied in detail. An appropriate SiO₂ layer can effectively induce the GO nanosheets to completely wrap the Fe₃O₄ NPs, forming a core-shell Fe₃O₄@SiO₂@GO composite where Fe₃O₄@SiO₂ NPs are firmly encapsulated by GO nanosheets. The optimized Fe₃O₄@SiO₂@GO sample exhibits a high saturated adsorption capacity of 253 mg·g?1 Pb(II) cations from wastewater, and the adsorption process is well fitted by Langmuir adsorption model. Notably, the composite displays excellent regeneration, maintaining a ~90% adsorption capacity for five cycles, while other samples decrease their adsorption capacity rapidly. This work provides a theoretical guidance to improve the regeneration of the GO-based adsorbents.     

摩擦焊接碳钢（EN24）和镍基高温合金（IN718）的显微组织和力学性能

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel (EN24) and nickel-based superalloy (IN718), and the microstructures of three distinct weld zones—the weld interface (WI)/thermo-mechanically affected zone (TMAZ), the heat-affected zone (HAZ), and the base metal—were examined. The joint was observed to be free of defects but featured uneven flash formation. Electron backscatter diffraction (EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ. Moreover, significant refinement in grain size (2–5 μm) was observed at the WI/TMAZ with reference to the base metal. The possible causes of these are discussed. The microhardness profile across the welded joint shows variation in hardness. The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates. The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.     

汽车暴露面板带有表面条状缺陷的夹杂物分布特征分析:一种定量电解方法

The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface. A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology, size, composition, quantity, and distribution of inclusions in the defect and non-defect zone of automobile exposed panel. The Al₂O₃ inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10 μm. The aggregation sections of the Al₂O₃ inclusions are distributed discretely along the rolling direction, with a spacing of 3–7 mm, a length of 6–7 mm, and a width of about 3 mm. The inclusion area part is 0.04%–0.16% with an average value of 0.08%, the inclusion number density is 40 mm?2 and the inclusion average spacing is 25.13 μm. The inclusion spacing is approximately 40–160 μm, with an average value of 68.76 μm in chain-like inclusion parts. The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002% and 1–2 mm?2, respectively, with the inclusion spacing of 400 μm and the size of Al₂O₃ being 1–3 μm.     

在酸性溶液中加压氧化三价砷离子和二价铁离子

The co-oxidation of As(III) and Fe(II) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150°C. It was confirmed that without Fe(II) ions, As(III) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200°C and an oxygen pressure up to 2.0 MPa. Fe(II) ions in the solutions did have a catalysis effect on the oxidation of As(III), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH·) and Fe(IV) in the oxidation process of Fe(II). The effects of such factors as the initial molar ratio of Fe(II)/As(III), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(III) and Fe(II) were studied. It was found that the oxidation of As(III) was limited in the co-oxidation process due to the accumulation of the As(III) oxidation product, As(V), in the solutions.     

活化天然矿石选择性还原二氧化碳为无定形碳

Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H₂ reduction. The temperature-programmed reduction of hydrogen (H₂-TPR) and temperature-programmed surface reaction of carbon dioxide (CO₂-TPSR) were carried out to investigate the processes of oxygen loss and CO₂ reduction. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H₂ atmosphere. Meanwhile, the activity and selectivity of CO₂ reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO₂ reduction at 300°C for 90 min over the activated natural magnetite was 2.87wt% higher than that over the natural magnetite.     

含钛高炉炉渣微波合成碳化钛及其介电性能测定

The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery; it can alleviate the environmental pressure caused by slag stocking. The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method. Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed. The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.     

写在《实验动物管理条例》发布实施三十周年

《实验动物管理条例》（以下简称条例）是我国第一部关于实验动物管理工作的行政法规）《条例》实施30年来,在实验动物工作规范化、法制化管理,保障实验动物和动物实验的质量,推动我国科技发展和民生保障等方面发挥了重要作用。但随着科技进步、社会经济发展和立法工作的深入,实验动物科学研究和管理工作中出现了诸多新情况和新问题,《条例》在实验动物管理工作中的作用已不能完全适应科技创新、经济与社会发展的需要。因此,修订《条例》并将其上升到法律层面,对规范实验动物管理工作,保证实验动物质量,保障实验动物福利,维护公共卫生安全,支撑科技创新,以及促进国际科技合作与交流具有非常重要的意义。     

独立通风笼盒系统内传热传质分析

目的 为了有效控制独立通风笼盒系统(individual ventilated cages, IVC)内环境的舒适性,保证笼盒内实验动物的生存和健康,对笼盒内的温度、湿度及氨浓度进行测试,并对笼盒内传热传质机理进行分析,同时为实验动物生存环境(密闭建筑空间、设备)控制提供参考。方法 小鼠75只,按数量递增顺序随机分为5组,饲养于同一架IVC设备内,分别对笼盒内的温度、湿度和氨浓度进行连续7 d的测试。结果 随着饲养天数的增加,笼盒内和房间内的温度差变化基本一致,相对湿度差和氨浓度差逐渐增大;同时笼盒内、外的氨浓度差同动物数量和时间均相关,有显著差异(P<0.05),即动物只数越多,时间越长,氨浓度差越大。结论 IVC笼盒内温度受设施内温度的影响较大;相对湿度主要与送风空气相对湿度和换气次数有关;氨浓度与换气次数和动物只数有关。     

卫星遥感监测全球大气气溶胶光学厚度变化

 全球大气气溶胶类型和含量变化与气候变化和大气环境污染密切相关,是气象学、环境学和医学研究关注的热点问题。为认识全球气溶胶分布基本特征,发现和跟踪全球气溶胶显著变化地区,本文利用美国NASA 发布的C6 版MODIS气溶胶光学厚度产品分析全球大气气溶胶光学厚度时空年变化特征及其影响因素;分析气溶胶光学厚度分布与中国霾区的关系,提出霾区治理的气溶胶光学厚度年平均值参考标准。分析2003-2014 年卫星监测的气溶胶光学厚度(AOD)空间分布特征显示,全球气溶胶光学厚度稳定高值区位于亚洲东部及其邻近太平洋海区、印度半岛及其邻近印度洋海区、非洲北部和中部及其邻近大西洋海区;重点变化关注区为俄罗斯西伯利亚东部增量区和南美洲亚马逊平原热带雨林减量区。气溶胶光学厚度高值地区的形成与沙尘暴、火山喷发、生物质燃烧、工业排放等自然源,以及工业污染物排放、交通运输、秸秆焚烧等人类活动造成的人为源气溶胶排放直接相关,并受气象因素和山脉等地形阻挡因素影响,这些因素的稳定性与季节变化最终形成全球气溶胶的时空分布特征。中国东部气溶胶光学厚度年平均值大于0.5 的区域为主要霾天气区,其中华北南部、黄淮、江淮、江汉地区和四川盆地为全球气溶胶光学厚度极端高值区,年平均极端高值达到0.8~1.0,为霾天气常态化发生区;通过全球气溶胶光学厚度量值分析认为,气溶胶光学厚度年平均值0.5 可作为中国大气环境最大承载量,中国东部地区高于此值的区域为主要大气污染控制区,大范围工业生产污染物减排可带来整体环境改善,通过工业结构调整有望降低的气溶胶污染中位比率为33%,平均比率为26.5%。     

长宁地区富有机质页岩脆性及与裂缝发育关系

页岩的脆性控制着裂缝的形成和演化,对页岩气层的体积改造和页岩气的增产极为关键。以川南长宁地区龙马溪组页岩为例,通过岩石矿物、地球化学和岩石力学等实验对龙一₁亚段的矿物组分、有机地球化学、孔隙-裂缝结构以及力学性质进行测试,分析不同脆性矿物、有机质以及埋深的页岩脆性特征及其与裂缝发育的关系。结果表明,龙一₁亚段脆性最高者为富有机质硅质页岩岩相,石英、长石和黄铁矿等脆性矿物的总含量大于50%,它们能够调节岩石断块的剪切滑移,所积累的能量大于完成岩石整体剪切破坏过程所需的能量;有机质及其在成熟过程中所产生的有机孔隙与微裂缝可促进裂缝的拓展、贯通以及连接,有机碳含量越高,裂缝系统越发育;随着埋深增加,页岩的脆性下降,岩石破裂模式由复杂的劈裂型向单一的剪切型转变;龙一₁¹、龙一₁²小层脆性矿物和有机碳含量最高,脆性指数分别达到了61.31%和60.70%,为压裂甜点层段。     

生活垃圾分类回收处理对周边土壤中铅、锰重金属污染的影响

为了研究生活垃圾分类回收处理对周边土壤中铅、锰重金属污染的影响,选用我国北方某市生活垃圾中转站及其附近1 km范围内的土壤作为研究样本,在中转站外设立一个垃圾回收对照区。给出土壤p H和土壤有机质测定方法,介绍了铅、锰含量测定过程。通过单因子污染指数和内美罗综合污染指数对土壤中铅、锰的污染情况进行衡量,分析了研究区域生活垃圾物理组成。为了使得到的结果更加准确,对铅、锰的分布特征及其和土壤理化性质间的关系进行分析,确定土壤对铅、锰重金属污染的影响程度。给出不同采样区表层0~20 cm土壤中重金属铅、锰的污染情况和污染指数评价结果。分析了土壤中重金属铅、锰化学形态分布情况。结果表明,土壤p H与有机质含量对生活垃圾分类回收中转站周边土壤中锰含量基本没有影响,可忽略;生活垃圾分类回收能够降低周边环境风险。     

卢卡奇"总体性的辩证法"再思考--读《历史与阶级意识》

本文主要依据卢卡奇的《历史与阶级意识》这一经典文本．从卢卡奇、马克思和黑格尔三者之间的关系出发，提出“总体性的辩证法”由以产生的思想渊源和历史背景，并探讨“总体性”范畴的具体含义。文章认为“总体性”首先是一种具体的总体性，即：部分在总体之中，又存留其个体性．总体具有高于部分的地位．部分只能在与总体的联系中才有意义。其次，“总体性的辩证法”是主体和客体相互作用写统一的辩证法．它仅限于社会历史领域，是研究社会历史中主、客体运动的概念。最后，分析论述了“总体性的渴求”与无产阶级的阶级意识之间的关系．指出“．电体性的辩证法”是卢卡奇为了消解实证主义的马克思主义哲学理论．重新恢复了马克思主义哲学的批判价值功能．从而实现了马克思主义哲学在本世纪初的一次重要转向．     

LPG储罐火灾与爆炸事故分析

近几年我国许多地方都新建了具有一定规模的LPG存储站,LPG储罐的安全可靠运行对安全生产和国民经济有着重大的影响。而LPG储罐容易受到人为因素和自然现象的影响而发生火灾、爆炸等恶性事故。通过对引起LPG储罐发生火灾、爆炸的因素进行了系统分析,建立了以LPG储罐火灾、爆炸为顶事件的事故树。通过对储罐火灾、爆炸事故树的分析,得到了事故树的各阶最小割集,通过对基本事件结构重要度的计算,确立了影响储罐事故的主要因素为LPG储罐超压和LPG泄漏,并提出了相应的改进措施以提高LPG储罐的运行可靠性。     

地理视角下的中国四大油气通道合理性分析

能源是社会经济发展必不可少的战略性资源,而能源中又以油气为主体,控制世界油气者,控制世界油气通道;控制世界油气通道者,控制世界经济.本文立足于世界经济贸易地理、国际政治地理的基本理论,采用数理统计法,利用ArcGis软件,对中国四大油气运输通道进行合理性分析.研究发现,四大通道的油气源地、路线选择和中国受益方面是具备合理性的,但每条通道都存在安全隐患.对此,本文提出了相应的对策建议,以保障中国油气进口的安全.     

泥浆泵滑块、滑套表面处理技术研究

通过对3NB-500型泥浆泵滑块、滑套摩擦副的失效分析,明确指出滑块表面热处理工艺不合格、表面硬度低、严重的磨料磨损等是其失效的主要原因;对比分析了各种表面强化技术特点,确定氧-乙炔火焰喷焊技术是强化滑块表面较为合理的方法。在磨损试验的基础上,优选的强化材料为PHNi60+WC15%,并制定了相应的喷焊工艺;同时,对滑块、滑套摩擦副的结构以及拉杆端密封结构进行了改进设计。现场使用证明,经表面处理后的滑块、滑套摩擦副使用效果很好。     

济阳坳陷中生界碎屑岩储层储集空间特征及控制因素

济阳坳陷中生界碎屑岩储层储集空间主要为溶解孔隙和裂缝,溶解物质主要为长石、岩屑等碎屑颗粒及碳酸盐胶结物;裂缝主要包括构造裂缝、压实裂缝和解理缝.构造裂缝主要形成于燕山期和喜山期,主要分布于不整合面附近的砂体中.碎屑岩储层储集性能主要受沉积作用、构造作用和成岩作用的控制,沉积作用是最重要的控制因素.其中三角洲砂体物性最好,河流砂体次之,冲积扇、扇三角洲及滨浅湖砂体物性较差.构造作用对储集物性的改造主要表现为断层活动和不整合,不整合面之下约100 m内储层裂缝和溶解孔隙最发育、物性明显提高.成岩作用对储层物性的影响受沉积作用和构造作用的控制,对储层的改造程度与沉积相带及距不整合面的距离有密切关系.中生界最有利的碎屑岩储层为不整合面之下约100 m内的河流或三角洲砂体.