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.     

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.     

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.     

PLGA/硬石复合涂层镁基纳米复合材料在植入应用时的体外生物活性和腐蚀行为

A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications. The microstructure, corrosion, and bioactivity of the coated and uncoated samples were assessed. Mechanical alloying followed by sintering was applied to fabricate the Mg–3Zn–0.5Ag–15NiTi nanocomposite substrate. Moreover, different contents of poly(lactic-co-glycolic acid) (PLGA) coatings were studied, and 10wt% of PLGA content was selected. The scanning electron microscopy (SEM) images of the bulk nanocomposite showed an acceptable homogenous dispersion of the NiTi nanoparticles (NPs) in the Mg-based matrix. In the in vitro bioactivity evaluation, following the immersion of the uncoated and coated samples in a simulated body fluid (SBF) solution, the Ca/P atomic ratio demonstrated that the apatite formation amount on the coated sample was greater than that on the uncoated nanocomposite. Furthermore, assessing the corrosion resistance indicated that the coatings on the Mg-based substrate led to a corrosion current density (i_corr) that was considerably lower than that of the substrate. Such a condition revealed that the coating would provide an obstacle for the corrosion. Based on this study, the PLGA/hardystonite (HT) composite-coated Mg–3Zn–0.5Ag–15NiTi nanocomposite may be suitably applied as an orthopedic implant biomaterial.     

矿山尾矿作为碱活化原料的研究进展

The mining industry produces billions of tons of mine tailings annually. However, because of their lack of economic value, most of the tailings are discarded near the mining sites, typically under water. The primary environmental concerns of mine tailings are related to their heavy metal and sulfidic mineral content. Oxidation of sulfidic minerals can produce acid mine drainage that leaches heavy metals into the surrounding water. The management of tailing dams requires expensive construction and careful control, and there is the need for stable, sustainable, and economically viable management technologies. Alkali activation as a solidification/stabilization technology offers an attractive way to deal with mine tailings. Alkali activated materials are hardened, concrete-like structures that can be formed from raw materials that are rich in aluminum and silicon, which fortunately, are the main elements in mining residues. Furthermore, alkali activation can immobilize harmful heavy metals within the structure. This review describes the research on alkali activated mine tailings. The reactivity and chemistry of different minerals are discussed. Since many mine tailings are poorly reactive under alkaline conditions, different pretreatment methods and their effects on the mineralogy are reviewed. Possible applications for these materials are also discussed.     

动态应变时效的应力状态依赖性:热硬化和蓝脆

This study aims to discover the stress-state dependence of the dynamic strain aging (DSA) effect on the deformation and fracture behavior of high-strength dual-phase (DP) steel at different deformation temperatures (25–400°C) and reveal the damage mechanisms under these various configurations. To achieve different stress states, predesigned specimens with different geometric features were used. Scanning electron microscopy was applied to analyze the fracture modes (e.g., dimple or shear mode) and underlying damage mechanism of the investigated material. DSA is present in this DP steel, showing the Portevin–Le Chatelier (PLC) effect with serrated flow behavior, thermal hardening, and blue brittleness phenomena. Results show that the stress state contributes distinctly to the DSA effect in terms of the magnitude of thermal hardening and the pattern of blue brittleness. Either low stress triaxiality or Lode angle parameter promotes DSA-induced blue brittleness. Accordingly, the damage mechanisms also show dependence on the stress states in conjunction with the DSA effect.     

关于钢水质量窄窗口稳定控制的思考

In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption (raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.     

不同应变速率下Mg?B4C纳米复合材料的力学性能表征

Magnesium has wide application in industry. The main purpose of this investigation was to improve the properties of magnesium by reinforcing it using B₄C nanoparticles. The reinforced nanocomposites were fabricated using a powder compaction technique for 0, 1.5vol%, 3vol%, 5vol%, and 10vol% of B₄C. Powder compaction was conducted using a split Hopkinson bar (SHB), drop hammer (DH), and Instron to reach different compaction loading rates. The compressive stress–strain curves of the samples were captured from quasi-static and dynamic tests carried out using an Instron and split Hopkinson pressure bar, respectively. Results revealed that, to achieve the highest improvement in ultimate strength, the contents of B₄C were 1.5vol%, 3vol%, and 3vol% for Instron, DH, and SHB, respectively. These results also indicated that the effect of compaction type on the quasi-static strength of the samples was not as significant, although its effect on the dynamic strength of the samples was remarkable. The improvement in ultimate strength obtained from the quasi-static stress–strain curves of the samples (compared to pure Mg) varied from 9.9% for DH to 24% for SHB. The dynamic strength of the samples was improved (with respect to pure Mg) by 73%, 116%, and 141% for the specimens compacted by Instron, DH, and SHB, respectively. The improvement in strength was believed to be due to strengthening mechanisms, friction, adiabatic heating, and shock waves.     

“质明”正解

"质明"的"质"训为"端始","质明"训为"黎明的开始"的观点不甚允当。"质"应当训为正,"质明"就是天正亮。"质明"不是"黎明的开始",而恰恰是黎明的"结束"。     

词义札记二则

前贤对古文的注释多有商榷之处。本文围绕古文“更取器用”之“更”和“众不见信”之“众”、“见”的训释进行讨论和辨析,提出释“更”为“取”,“众”不作“终”训,“见”当属指代用法．     

腾冲“罗古城”、“罗密城”的历史渊源及其语义考证

腾冲的“罗古城”、“罗密城”是白族的先民在宋“大理国”时期所建。它们以白语命名,“罗古城”是“虎踞的关口之城”,“罗密城”是“老虎的生命之城”。它们不是后人传说的“哥哥”城、“妹妹”城的意思。     

"象"的境界与"数"的真理--作为中西古典美学意义之发端的老子"象论" 与毕达哥拉斯学派的"数论"

老子“象论”与毕达哥拉斯学派“数论”分别构成了中西古典美学的意义之发端。两在思想路向上存在着巨大的差异。老子“象论”及其人生论的思想路向启发了中国古典美学中的“意象”本体论和以“境界”为最高审美理想的思想;毕达哥拉斯学派“数论”及其知识论的思想路向启发了西方古典美学中的“形式”本体论和以“真理”为最高审美理想的思想。     

《论语》"当仁"章释义考辨

考《论语》“当仁,不让于师”一章注释,或以“谦让”释“让”,以“老师”“先生”释“师”,或以“谦让”释“让”,以“众”释“师”。笔者认为二说俱有偏误,从语言文字、孔子思想、社会实情三点辨正。     

<诗经>释义四题

结合语词产生的环境和具体运用情况,对“雨雪”、“窈窕”、“采采”、“愿言”、“薄言”等词语的意义作出较合理的解释。     

清代两位诗话家对诗趣的集中论评与阐说

清代袁枚、朱庭珍对诗趣予以了集中论评与阐说。袁枚评诗推尚偏于由才性而催生出的"趣"的审美形态,他以"趣"为审美标的,以性灵为根本,以天才、真、自然为支点,建构出一个有别于他人的诗趣论系统。朱庭珍评诗反对"恶趣"、"魔趣",推尚意趣充蕴之作;他强调作诗要"培之以理趣之府",提出了"意趣活泼"的审美要求,在诗趣的生成创造上,则论及到由"情"而"趣"、由"思"而"趣",对诗中之趣语的运用也予以了界划。他们为古典诗趣论的最终深化和完善做出了突出的贡献。     

“玉山雅集”与“北郭诗社”的差异性研究

"玉山雅集"与"北郭诗社",以张士诚入吴为标志,先后繁荣于吴中地区。同为吴中文人团体,二者有巨大的差异,表现在三个层面:在雅集方式上,呈现出从"娱乐化"向"文艺化"的转变;在文人心态上,表现为从"纵欲"到"闲适"、从"庆幸"到"无奈"的转变;在诗学思想上,诗人对诗歌功能的理解、诗法与诗体的选择及诗歌的审美风貌都不同。这三个层面相辅相成,既体现了易代之际吴中文人内部的差异性,也反映了吴中文人的整体风貌。     

非匀强电场对颗粒污垢的抑垢特性

目前,电场抑垢研究兴趣集中于电场对碳酸钙晶体形貌的改变,电场对已成垢的颗粒是否有抑垢作用鲜有研究。针对电场颗粒污垢抑垢机理不明的问题,提出非匀强电场颗粒物污垢抑垢模型,解释了电场对流体管道内污垢颗粒存在抑垢作用。电场60V至180V、频率50Hz、颗粒质量100条件下研究结果表明:匀强电场并不会使颗粒产生抑垢作用,颗粒污垢在非匀强电场受到介电泳力（）,改变原本运动轨迹,达到抑垢的效果。随着电场强度升高,碳酸钙颗粒受到的从,升至。硫酸钙受到的从升至。碳酸镁颗粒受到的升至。电场强度对多种污垢颗粒产生的,是影响抑垢效果的关键因素。     

道德与天地：论新理学“境界”之如何可能-兼答邓联合博士的一个问题

冯友兰新理学的"境界"是以"觉解"为枢纽的.在新理学的境界思想中, "觉解"有"形上"和"形下"的两个向度.<新理学>严格区分了"形上"与"形下";而在<新原人>的道德境界与天地境界里,本来所严格区分的"形上"与"形下"又得到了有机的结合;从而使新理学之道德境界与天地境界的实现成为可能.