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.     

微生物浸矿技术在我国的研究现状及发展前景

As the world’s second largest economy experiencing rapid economic growth, China has a huge demand for metals and energy. In recent years, China ranks first, among all the countries in the world, in the production and consumption of several metals such as copper, gold, and rare earth elements. Bioleaching, which is an approach for mining low grade and refractory ores, has been applied in industrial production, and bioleaching has made great contributions to the development of the Chinese mining industry. The exploration and application of bioleaching in China are reviewed in this study. Production and consumption trends of several metals in China over the past decade are reviewed. Technological processes at key bioleaching operations in China, such as at the Zijinshan Copper Mine and Mianhuakeng Uranium Mine, are presented. Also, the current challenges faced by bioleaching operations in China are introduced. Moreover, prospects such as efficiency improvement and environmental protection are proposed based on the current situation in the Chinese bioleaching industry.     

不同结构和形态的天然镁硅酸盐:与K反应制备生物柴油的K2MgSiO4催化剂

In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile (which have the same general formula Mg₃Si₂O₅(OH)₄), and talc (Mg₃Si₄O₁₀(OH)₂) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20wt% K and treatment at 700–900°C led to a solid-state reaction to mainly form the K₂MgSiO₄ phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K₂MgSiO₄ formation. All the materials showed catalytic activity for the transesterification of soybean oil (1:6 of oil : methanol molar ratio, 5wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K₂MgSiO₄.     

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.     

贤能优劣论

统治阶级在不同时期有着不同的用人选择。“贤”是“德”的又一种表述,没有标准可界定,统治阶级择人用人,在战乱等非常用人时期,多用“能”,而在和平守成时期,立即改为用“贤”,而总是达不到预期的目的。而“能”,既可治国,又可安邦,却不常被用。     

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。     

从“危机”中寻找“机遇”

发端于美国次贷危机的金融危机已经对中国的实体经济造成明显的冲击和影响,突出表现为外部需求减少,而且这种冲击和影响目前看起来还没有马上停止的迹象,其深度和广度有可能在今年进一步扩大.     

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。     

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。     

关于"李约瑟问题"与"诺贝尔现象"的思考

一、对“李约瑟问题”的反思上个世纪 ,著名的科学家李约瑟曾经提出一个问题 :在公元前１世纪到公元１４世纪的漫长岁月中 ,中国科学和技术曾处于世界领先地位 ,并对整个人类文明做出了许多原创性的贡献。但在近三四百年中 ,中国社会为什么没有能够孕育出近代科学和技术？是什么原因导致近代中国科学和技术落后于西方的？这就是所谓的“李约瑟问题”。围绕“李约瑟问题” ,中外学者不但从不同的角度探讨了中国科学和技术本身所存在的缺陷 ,而且更多地讨论了中国社会和文化在政治、经济、文化等方面存在的种种不足和局限。这些讨论对于中国科…     

怎样"求"才能获得"是"

实事求是包括了解、掌握“实事”与从“实事”中“求是”这两个方面的工作,但许多研究者却很少涉及如何从“实事”中“求是”的问题。这是一个不足。毛泽东“求是”,一是用分析与综合的方法,分析矛盾、矛盾方面以及条件的特点,综合、比较,得出结论。二是用归纳与概括的方法,概括实践发现的联系,揭示出事物运动的规律性。近代科学的早期,人们认识规律采用的主要是“实验一归纳法”,现代科学则侧重于运用“假设一演绎法”。解决从经验事实中“求是”的问题则有主要依靠逻辑方法和主要依靠理智去发明等主张。这些不同的方法都有许多成功的实例。我们应当学习、掌握这些方法,并把它们结合起来,以利于我们在实践中真正做到实事求是。     

《孽海花》之“孽海”与“花”新解

正确理解“孽海”与“花”的含义,有助于深入解读小说《孽海花》。本通过对小说本和有关资料的研析,指出《孽海花》中的“孽海”主要指当时正在沉沦的中国社会环境,“花”则既指名妓傅彩云,也指晚清“名士”。     

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。