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.     

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.     

采用超声组装与滚压工艺制备铝–碳纳米管复合材料

This study introduced a novel fabrication of aluminum–carbon nanotube (CNT) composites by employing bulk acoustic waves and accumulative roll bonding (ARB). In this method, CNT particles were aligned using ultrasonic standing wave in an aqueous media, and the arrayed particles were precipitated on the aluminum plate substrate. Then, the plates rolled on each other through the ARB process with four passes. Optical and scanning electron micrographs demonstrated the effective aligning of CNTs on the aluminum substrate with a negligible deviation of arrayed CNTs through the ARB process. The X-ray diffraction pattern of the developed composites showed no peaks for carbon and aluminum carbide. In addition, tensile tests showed that the longitudinal strength of the specimens processed with aligned CNTs was significantly greater than that of the specimens with common randomly dispersed particles. The proposed technique is beneficial for the fabrication of Al–CNT composites with directional mechanical strength.     

几种特殊模糊二元关系的探讨

讨论了竞赛，全序，偏序，弱序，拟序，严格全序，严格偏序，严格弱序八种特殊的二元关系，指出了它们之间的联系。如全序关系一定是弱序关系，弱序关系一定是拟序关系等；以T，S三角模算子为基础，在丁非对称，S强完全，T传递，S负传递这些概念的基础上，分别给出了模糊竞赛，模糊全序，模糊偏序，模糊弱序，模糊拟序，模糊严格全序，模糊严格偏序，模糊严格弱序关系的定义，并讨论了它们之间的联系，如T-S全序一定是T-S弱序，T-S弱序一定是T拟序等，得出了与普通情形下相一致的结论。     

二维顺序统计量的概率分布

研究了二维样本的次序统计量的分布问题,给出了依第一分量排序的次序统计向量的分布的计算公式,证明了在给定第一分量的一个次序统计量的条件下,第二分量的次序统计量的条件分布与某个一维样本的次序统计量的分布是相同的。     

保序且保等价部分变换半群上的自然偏序关系

研究了保序且保等价部分变换半群上的自然偏序关系.首先给出了保序且保等价部分变换半群上的自然偏序关系的定义.利用自然偏序关系定义,考察了此半群中两个元素何时关于此自然偏序关系是相关的,并探讨了关于此偏序关系左(右)相容的元素,所得结果推广了保序且保等价变换半群上的自然偏序关系.     

Fast algorithms for Walsh transform in bit-reversed sequency order

Bit-reversed sequenry order or bit-reversed Walsh order (M) is presented. Walsh functions in this order can be processed cnsily, and there is a simple relation between sequency order and bit-reversed sequency order. 8 fast algorithms for discrete Walsh transform in bit-reversed sequency order are given.     

复合反应的胶束催化研究Ⅱ—— CTAB胶束对结晶紫褪色反应的影响

研究了在５．００×１０－３ｍｏｌＬ－１ＮａＯＨ溶液中,表面活性剂ＣＴＡＢ胶束对结晶紫褪色反应的影响,建立了平行一级和二级反应胶束催化的数学模型,得出了胶束相中的一级和二级反应速率常数．实验结果表明,ＣＴＡＢ胶束对结晶紫的一级反应表现出催化作用,ＣＴＡＢ胶束相中的一级速率常数为本体相中一级速率常数的１６２５倍,而ＣＴＡＢ胶束对结晶紫的二级反应表现出禁阻作用,ＣＴＡＢ胶束相中的二级速率常数为本体相中二级速率常数的０．００７１１倍     

单位圆上线性微分方程解的几个性质

研究了单位圆内解析函数的线性微分方程解的性质,得到某些一阶、二阶、高阶线性微分方程所有解为不可允许解的充分条件,以及二阶、高阶线性微分方程所有解为无穷级的一个充分条件.     

有关高阶的Genocchi数、Euler数与Bernoulli数的一些恒等式

根据高阶Euler数、高阶Bernoulli数及高阶Genocchi数定义,利用发生函数方法建立起高阶Euler数、高阶Bernoulli数与高阶Genocchi数之间的恒等式,得到这些高阶数分别用其他普通数表示的几组计算公式,推广了已有的相关结果.     

配价理论与汉语语序研究

语序问题是语法的核心问题,汉语语序的特点在很大程度上能够反映出汉语的特点。笔者根据配价理论建立起汉语语序的基本模型,并以此为参照描写汉语语序的种种变异形式：（1）价成分位序的改变：主要包括单纯的位序改变、分裂移位,以及部分同前置词隐现有关的位序改变。（2）价成分数量的改变,包括价成分的减少、增加及汉语特有的共价现象。笔者认为语序变异的深层动因是汉语”线性增量”的表意需要;并列举了语序研究的一个实例：语序变异研究对汉语作为第二语言的教学实践有着积极的促进作用。     

高阶非齐次线性微分方程解沿径向的振荡性质

运用角域上值分布的理论和方法,研究了高阶非齐次线性微分方程的无穷级解沿径向上的振荡性质,得到了方程的无穷级解沿Borel方向上的超级和超级零点收敛指数的估计.     

Laplace-Stieltjes变换所定义的整函数的增长性

研究了由Laplace-Stieltjes变换所定义的整函数的级和下级,通过适当引入序列O□λfn↑+∞,建立了该变换的级和下级与其系数及指数之间的关系,即该变换的级和下级的充分必要条件,推广了Dirichlet级数的相关结果。