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.     

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.     

人工闪锌矿氧压酸浸过程中Cu2+的催化机理研究

The potential autoclave was used to study the catalytic mechanism of Cu2+ during the oxygen pressure leaching process of artificial sphalerite. By studying the potential change of the system at different temperatures and the SEM–EDS difference of the leaching residues, it was found that in the temperature range of 363–423 K, the internal Cu2+ formed a CuS deposit on the surface of sphalerite, which hindered the leaching reaction, resulting in a zinc leaching rate of only 51.04%. When the temperature exceeds 463 K, the system potential increases steadily. The increase in temperature leads to the dissolution of the CuS, which is beneficial to the circulation catalysis of Cu2+. At this time, the leaching rate of Zn exceeds 95%. In addition, the leaching kinetics equations at 363–423 and 423–483 K were established. The activation energy of zinc leaching at 363–423 and 423–483 K is 38.66 and 36.25 kJ/mol, respectively, and the leaching process is controlled by surface chemical reactions.     

超声振动辅助钨极惰性气体焊接异种金属 316L 和 L415

Ultrasonic vibration assisted tungsten inert gas welding was applied to joining stainless steel 316L and low alloy high strength steel L415. The effect of ultrasonic vibration on the microstructure and mechanical properties of a dissimilar metal welded joint of 316L and L415 was systematically investigated. The microstructures of both heat affected zones of L415 and weld metal were substantially refined, and the clusters of δ ferrite in traditional tungsten inert gas (TIG) weld were changed to a dispersive distribution via the ultrasonic vibration. The ultrasonic vibration promoted the uniform distribution of elements and decreased the micro-segregation tendency in the weld. With the application of ultrasonic vibration, the average tensile strength and elongation of the joint was improved from 613 to 650 MPa and from 16.15% to 31.54%, respectively. The content of Σ3 grain boundaries around the fusion line zone is higher and the distribution is more uniform in the ultrasonic vibration assisted welded joint compared with the traditional one, indicating an excellent weld metal crack resistance.     

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.     

篮球运动员篮球意识训练的研究

篮球运动中＂篮球意识＂训练,一直是篮球训练工作的重要课题之一,也是提高篮球运动水平的一个重要内容,文章对篮球意识的构成要素、篮球意识的培养方法进行了探讨,以期对篮球运动员的意识训练提供参考。     

浅谈篮球运动中篮球意识的培养

为了了解篮球意识对篮球运动员的影响,通过文献资料法和观察法,对篮球运动员的篮球意识进行研究分析。发现提高运动员的篮球意识有利于提高技、战术,从而得出篮球运动员应加强篮球意识的培养。     

浅谈篮球运动员篮球意识的培养

一个优秀运动员必须具有自觉、积极的“篮球意识”，而“篮球意识”的形成并非一时之事，它必须有较长时间的潜移 默化的熏陶、渗透。为此，笔者认为，培养篮球运动员的“篮球意识”更重要的是要从初学者抓起，从各方面逐步培养，只有这样才 能加快这一意识的形成。笔者对篮球运动员“篮球意识”的培养进行了分析，提出培养“篮球意识”的方法。     

论篮球运动员“篮球意识”的培养

本文通过对篮球队员“篮球意识”的培养和探讨,从技术训练、战术训练、作用训练等几方面进行了阐述,论述了篮球意识是篮球运动员最宝贵的精髓,是比赛中指导正确行动的“活的灵魂”。     

篮球普修课加强学生篮球意识培养初探

篮球意识在比赛中起重要作用，直接影响技术、战术水平的发挥．本文通过运用文献资料、逻辑推理等研究方法．对篮球意识的培养进行探讨，认为在教学中加强对学生意识的培养，可以有效的提高篮球教学水平．     

试论篮球运动员篮球意识的培养与训练

篮球运动是一项十分复杂多变的运动项目，需要篮球运动员在比赛中能够灵活的运用技、战术，能够正确反映篮球运动的规律性，特殊心理素质和生理机能的反射能力，这就是篮球意识，它被称为篮球运动的灵魂．篮球意识的培养需要长期训练和比赛的积累，跨人大学的运动员是培养篮球意识的最佳时期．而篮球意识的培养与训练，是一个循序渐进、日积月累的过程，很大程度上取决于教练员对运动员的科学培养和训练．     

从男篮世锦赛谈中国篮球与欧洲篮球的差距与对策

采用文献资料法、录像观摩法、分析对比法对2010年男篮世锦赛中国篮球与欧洲篮球的分析、比较,可以看出:中国篮球在前锋和后卫方面比较欠缺,中国队球员在身体素质、成长环境等方面都落后于欧洲联赛水平,机制方面也有必要向欧洲学习.     

从中美篮球运动现状思考篮球运动的市场化

通过中、美职业篮球现状、大学生篮球现状、中小学及社会大众篮球运动水平发展现状的对比分析 ,探讨市场化背景下中国篮球运动发展的问题之所在 ,并就中国篮球运动发展前景提出若干建议     

重论如何培养运动员的篮球意识

意识是行动的前导,决定行动的方向与质量。基于篮球运动项目本身特点和运动员实际的比赛意识状态,本文提出了运动员的篮球意识分为即成的篮球心理定势反应和篮球痕迹的专项智能两部分,并进一步提出了在这一理论指导下的运动员篮球意识的培养原则和策略。     

重论如何培养运动员的篮球意识

意识是行动的前导,决定行动的方向与质量.基于篮球运动项目本身特点和运动员实际的比赛意识状态,本文提出了运动员的篮球意识分为即成的篮球心理定势反应和篮球痕迹的专项智能两部分,并进一步提出了在这一理论指导下的运动员篮球意识的培养原则和策略.