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.     

氧化锌矿物浸出渣中铅、锶的提取及动力学分析

NH₄HCO₃ conversion followed by HCl leaching was performed and proven to be effective in extracting Pb and Sr from zinc extracted residual. The mechanism and operating conditions of NH₄HCO₃ conversion, including molar ratio of NH₄HCO₃ to zinc extracted residual, NH₄HCO₃ concentration, conversion temperature, conversion time, and stirring velocity, were discussed, and operating conditions were optimized by the orthogonal test. Experimental results indicate that NH₄HCO₃ conversion at temperatures ranging from 25 to 85°C follows the shrinking unreacted core model and is controlled by inner diffusion through the product layer. The extraction ratios of Pb and Sr under optimized conditions reached 85.15% and 87.08%, respectively. Moreover, the apparent activation energies of Pb and Sr were 13.85 and 13.67 kJ·mol?1, respectively.     

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.     

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.     

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.     

说滕文公之"文"

我们平时所说的战国时期的滕文公 ,实际上是滕元公 ,至于他为什么后世称他为“文”,则可以从几个方面来考虑 :其一 ,作为谥号的“元”和“文”差别并不是很大 ;其二 ,春秋战国时期的谥法并没有得到应有的尊重 ;其三 ,我们还要注意到儒家思想对中国社会文化影响的渐进性。     

对“以人为本”中“人”的几种理解的辨析

学界对"以人为本"当前主要有四种理解。把"以人为本"中的"人"理解为"人民群众",是从政治视角而言的,针对的是"少数人"范畴;把"以人为本"中的"人"理解为"全体公民",是从法律视角而言的,针对的是"部分公民"范畴;把"以人为本"中的"人"理解为"人类",是从人类共同利益视角而言的,针对的是"自然"和"物"范畴;把"以人为本"中的"人"理解为"具体的个体的人",是从工作落实视角而言的,针对的是理论层面抽象的"人"范畴。应在特定的范围内理解"以人为本"中的"人",超出其特定适应范围便容易导致对其中的"人"的误读。党中央提出的"以人为本"中的"人",无疑应当是指中国最广大人民群众,而学界所作的拓展性理解则是适应于特定范围、解决特定问题的。     

从“无兵的文化”到“竞逐富强”

一个民族的兴盛与一个民族是否具有捍卫自己利益的能力和决心有关,也与一个能够发挥市场优势的制度安排有关。因此,在一个以竞逐富强(thepursuitofpower)为原则而发展起来的现代世界中,中华民族在进行经济与政治制度变革的同时,必须改变自己文化上无兵的传统。     

国书馆“传统”与“现代”论

从藏书结构、服务模式、管理方式等方面阐述了传统图书馆模式的特点,并从图书馆的虚拟化和图书馆管理的人本化方面分析了现代图书馆的发展走向。     

审判质量管理的“满意”与“公正”之间

公众对案件的"满意度"与"司法公正"的内涵本身存在的原理性冲突,当事人对事件结果公正的不同理解、媒体对社会舆论的导向,直接影响着公众对司法案件的认识和评价。一旦舆情被某种因素引导,社会舆论就容易发展趋向于一种或几种极端的论调,产生"群体极化"现象。其中非理性的部分社会舆情将产生巨大的力量,可能引发"满意"与司法公正的较量。"河北王朝案"就是发生在审判质量管理背景下舆情与司法的一次激烈冲突。因此,应弱化以"满意度"作为案件质量评估的指标,从而回归司法独立、司法公正的本质。     

"真"的创世与"真"的毁灭--《花腔》之"花腔"叙事

<花腔>的发表引起评论界的关注.<花腔>的出众之处不完全在于文本作者得意、论者激赏的"先锋性"的两套叙事话语体系的设置,更在于通过调用"真"的创世与毁灭的叙事智慧对历史话语权的质疑和对"红色"知识分子荒谬人生的深刻阐释.     

重新审视"环境决定论"——《人文类型》所给予的启示

自然环境为人类文化的创造提供了活动舞台,对人类生活具有重要意义,尤其是人类社会早期发展阶段对自然环境的依赖是不言自明的。人类学家和地理学家探求文化特质地理分布的简单原因,在于环境决定论的解释模式是基于世界性探险而搜集到的大量有关人类差异材料进行分类和解释的一种简单的方法。文章从早期理论学者开始进行追述和回顾,认为:如果将强调或者突出“气候的作用”的学者归为“环境决定论者”,这种扩大“气候”外延的论说方式不能成立。     

论《酉阳杂俎》的“史性”特征

在中国古代小说的发展初期,对于小说的功能,论者往往定之以＂可补经史之阙＂。因此在古代小说的发展之初,小说常在作者的写作态度以及叙述故事、塑造人物等方面体现出鲜明的＂史性＂特征。段成式的《酉阳杂俎》虽然成书于＂始有意为小说＂[1]（P39）的唐朝,但是从其创作态度、写作方法、内容题材等来看,仍具有突出的＂史性＂特征。     

从“实然”与“应然”解“世风日下”之迷

古今中外,哀叹“世风日下”的呼声不绝于耳,在我国社会转型时期“世风日下”观念更加强化。笔者在文中从社会转型期市场经济条件下人们道德观念领域的“实然”与“应然”的矛盾入手,对“世风日下”观念在当前社会中异常强化的原因进行了探析并对道德嬗变的走向进行了展望,对于解决人们在社会转型时期的道德迷茫有一定的现实意义。     

对"矛盾"、"对立"范畴的再认识

韩非的“矛盾”富言属于逻辑矛盾。他的“矛盾”思想则是非此即彼、非彼即此,二者必居其一。这种仅仅在对立两极中的思维方法并非完全正确。哲学上的辩证关系,借用“矛盾”、“对立”范畴来表述,也不十分恰当,因为矛与盾不是对立的双方,而辩证关系也应包括对立统一、鼎立统一、多立统一。所以我们必须确立立体矛盾观,即对立面-中介-对立面,或正中反矛盾论,或同异反分析法。