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.     

微波预处理对复杂铜矿磨矿及浮选动力学的影响

The effect of CaCO₃, Na₂CO₃, and CaF₂ on the reduction roasting and magnetic separation of high-phosphorus iron ore containing phosphorus in the form of Fe₃PO₇ and apatite was investigated. The results revealed that Na₂CO₃ had the most significant effect on iron recovery and dephosphorization, followed by CaCO₃, the effect of CaF₂ was negligible. The mechanisms of CaCO₃, Na₂CO₃, and CaF₂ were investigated using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectrometry (SEM–EDS). Without additives, Fe₃PO₇ was reduced to elemental phosphorus and formed an iron–phosphorus alloy with metallic iron. The addition of CaCO₃ reacted with Fe₃PO₇ to generate an enormous amount of Ca₃(PO₄)₂ and promoted the reduction of iron oxides. However, the growth of iron particles was inhibited. With the addition of Na₂CO₃, the phosphorus in Fe₃PO₇ migrated to nepheline and Na₂CO₃ improved the reduction of iron oxides and growth of iron particles. Therefore, the recovery of iron and the separation of iron and phosphorus were the best. In contrast, CaF₂ reacted with Fe₃PO₇ to form fine Ca₃(PO₄)₂ particles scattered around the iron particles, making the separation of iron and phosphorus difficult.     

不同硅饱和系数水榴石的碳酸化分解动力学

Carbonated decomposition of hydrogarnet is one of the vital reactions of the calcification–carbonation method, which is designed to dispose of low-grade bauxite and Bayer red mud and is a novel eco-friendly method. In this study, the effect of the silica saturation coefficient (x) on the carbonation of hydrogarnet was investigated from the kinetic perspective. The results indicated that the carbonation of hydrogarnets with different x values (x = 0.27, 0.36, 0.70, and 0.73) underwent two stages with significantly different rates, and the kinetic mechanisms of the two stages can be described by the kinetic functions R3 and D3. The apparent activation energies at Stages 1 and 2 were 41.96–81.64 and 14.80–34.84 kJ/mol, respectively. Moreover, the corresponding limiting steps of the two stages were interfacial chemical reaction and diffusion.     

一种超重力燃烧合成制备高性能高熵合金的新方法

A new method of high-gravity combustion synthesis (HGCS) followed by post-treatment (PT) is reported for preparing high-performance high-entropy alloys (HEAs), Cr_0.9FeNi_2.5V_0.2Al_0.5 alloy, whereby cheap thermite powder is used as the raw material. In this process, the HEA melt and the ceramic melt are rapidly formed by a strong exothermic combustion synthesis reaction and completely separated under a high-gravity field. Then, the master alloy is obtained after cooling. Subsequently, the master alloy is sequentially subjected to conventional vacuum arc melting (VAM), homogenization treatment, cold rolling, and annealing treatment to realize a tensile strength, yield strength, and elongation of 1250 MPa, 1075 MPa, and 2.9%, respectively. The present method is increasingly attractive due to its low cost of raw materials and the intermediate product obtained without high-temperature heating. Based on the calculation of phase separation kinetics in the high-temperature melt, it is expected that the final alloys with high performance can be prepared directly across master alloys with higher high-gravity coefficients.     

窄板坯结晶器内连铸工艺参数对钢液流场的影响

Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting (CC) molds with narrow widths for the production of automobile exposed panels. Reasonable agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC process. The simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the mold. Increases in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation zone. The flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min?1 and casting speed of 1.7 m·min?1. Under the present experimental conditions, the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.     

电渣重熔脱硫技术研究进展

Electroslag remelting (ESR) gives a combination of liquid metal refining and solidification structure control. One of the typical aspects of liquid metal refining during ESR for the advanced steel and alloy production is desulfurization. It involves two patterns, i.e., slag–metal reaction and gas–slag reaction (gasifying desulfurization). In this paper, the advances in desulfurization practices of ESR are reviewed. The effects of processing parameters, including the initial sulfur level of consumable electrode, remelting atmosphere, deoxidation schemes of ESR, slag composition, melting rate, and electrical parameters on the desulfurization in ESR are assessed. The interrelation between desulfurization and sulfide inclusion evolution during ESR is discussed, and advancements in the production of sulfur-bearing steel at a high-sulfur level during ESR are described. The remaining challenges for future work are also proposed.     

利用皮秒激光烧蚀制备非球形铝纳米颗粒

We report the picosecond laser ablation of aluminum targets immersed in a polar organic liquid (chloroform, CHCl₃) with ~2 ps laser pulses at an input energy of ~350 μJ. The synthesized aluminum nanoparticles exhibited a surface plasmon resonance peak at ~340 nm. Scanning electron microscopy images of Al nanoparticles demonstrated the spherical morphology with an average size of (27 ± 3.6) nm. The formation of smaller spherical Al nanoparticles and the diminished growth could be from the formation of electric double layers on the Al nanoparticles. In addition to spherical aluminum nanoparticles, triangular/pentagonal/hexagonal nanoparticles were also observed in the colloidal solution. Field emission scanning electron microscopy images of ablated Al targets demonstrated laser induced periodic surface structures (LIPSSs), which were the high spatial frequency LIPSSs (HSF-LIPSSs) since their grating period was ~280 nm. Additionally, coarse structures with a period of ~700 nm were observed.     

Mineral transition and formation mechanism of calcium aluminate compounds in CaO?Al2O3?Na2O system during high-temperature sintering

The mineral transition and formation mechanism of calcium aluminate compounds in CaO?Al₂O₃?Na₂O system during the high-temperature sintering process were systematically investigated using DSC?TG, XRD, SEM?EDS, FTIR, and Raman spectra, and the crystal structure of Na₄Ca₃(AlO₂)₁₀ was also simulated by Material Studio software. The results indicated that the minerals formed during the sintering process included Na₄Ca₃(AlO₂)₁₀, CaO·Al₂O₃, and 12CaO·7Al₂O₃, and the content of Na₄Ca₃(AlO₂)₁₀ could reach 92wt% when sintered at 1200°C for 30 min. The main formation stage of Na₄Ca₃(AlO₂)₁₀ occurred at temperatures from 970 to 1100°C, and the content could reach 82wt% when the reaction temperature increased to 1100°C. The crystal system of Na₄Ca₃(AlO₂)₁₀ was tetragonal, and the cells preferred to grow along crystal planes (110) and (210). The formation of Na₄Ca₃(AlO₂)₁₀ was an exothermic reaction that followed a secondary reaction model, and its activation energy was 223.97 kJ/mol.     

含细夹层的分矿充填层中流动特性的可视化

Ore particles, especially fine interlayers, commonly segregate in heap stacking, leading to undesirable flow paths and changeable flow velocity fields of packed beds. Computed tomography (CT), COMSOL Multiphysics, and MATLAB were utilized to quantify pore structures and visualize flow behavior inside packed beds with segregated fine interlayers. The formation of fine interlayers was accompanied with the segregation of particles in packed beds. Fine particles reached the upper position of the packed beds during stacking. CT revealed that the average porosity of fine interlayers (24.21%) was significantly lower than that of the heap packed by coarse ores (37.42%), which directly affected the formation of flow paths. Specifically, the potential flow paths in the internal regions of fine interlayers were undeveloped. Fluid flowed and bypassed the fine interlayers and along the sides of the packed beds. Flow velocity also indicated that the flow paths easily gathered in the pore throat where flow velocity (1.8 × 10?5 m/s) suddenly increased. Fluid stagnant regions with a flow velocity lower than 0.2 × 10?5 m/s appeared in flow paths with a large diameter.     

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。     

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。     

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。     

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。     

"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。     

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。     

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。     

《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”。