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.     

以胡锦涛同志为总书记的党中央对党的思想政治工作理论的新贡献

党的十六大以来,以胡锦涛同志为总书记的党中央根据思想政治工作面临的新形势、新任务和新要求,提出了一系列的新思想、新观点和新论断,为新世纪新阶段的思想政治工作,提供了新指导,做出了新定位,指明了新目标,拓展了新内容,开辟了新途径,对党的思想政治工作理论做出了新贡献。     

新型城市化研究综述

学术界对新型城市化研究主要集中在新型城市化的概念、新型城市化与新型工业化的关系、新型城市化道路、城市化存在阶段性和地域性、城市化中政府作用等方面。新型城市化研究有许多创新之处,也存在许多值得商榷之处。     

安徽近年高等植物分类研究概述

本文总结十余年来在安徽省境内发现的50种新的植物分类群,包括1新属、1新组合、31新种、1新亚种、14新变种、2新变型,其中景天科7种、百合科5种、唇形科5种、马兜铃科3种、禾本科7种、其他植物23种.并结合地理学、生态学及药用植物亲缘关系等,对其中部分新种的药用价值的开发利用进行了探讨.     

新媒体时代中原经济区新农村文化建设研究

“中原经济区”战略对辖区新农村文化建设有着巨大推进作用,而具有时代特色的新媒体．对中原经济区新农村文化建设也发挥着重要作用。因此,建设中原经济区新农村文化,须结合新媒体,突出其工作重要性;利用新媒体,提高新农村文化工作趣味性;依托新媒体,注重新农村文化工作经常性;紧抓新媒体,增强新农村文化工作实效性。     

新疆青海极端环境发现大量未知放线菌

 从新疆、青海的重盐碱地区、盐湖采集样品,分离其中的嗜盐、嗜碱及低温放线菌.研究了它们在几种盐的不同浓度,不同 pH条件下的生长情况.利用多相分类程序进行鉴定,发现嗜盐放线菌、放线细菌的新科 1个(Yaniaceae),新属 2个(Yania and Streptomonospora),新种8个,嗜碱放线菌新种4个,低温放线菌新种1个.对其中部分新种、新属做了描述.认为新疆、青海的重盐碱地区蕴藏着大量的未知放线菌资源 ;新菌种必然有新基因,新产物,新活性和新用途,是药物开发的重要来源.     

中国自由生活革螨调查报告(Ⅻ)(蜱螨亚纲:中气门目)

通过整理和鉴定,有革螨12科20属32种,其中省区新记录14种。包括厉螨科Laelapidae西宁下盾螨Hypoaspis xiningensis Ma et Lin, 2009(西藏自治区新记录);湖南下盾螨Hypoaspis hunanensis Ma et Zheng, 2000(云南省新记录)。镰螨科Blattisocidae帕尔巴特手绥螨Cheiroseius parbatensis Evans et Hyatt, 1960(西藏自治区新记录)。裂胸螨科Aceosejidae半裂北绥螨Arctoseius semiscissus(Berlese, 1892)(山西省新记录)。寄螨科Parasitidae邓氏寄螨Parasitus tengkuofani Ma, 1995(西藏自治区新记录)。囊螨科Ascidae安氏囊螨Asca anwenjui Ma,2003(西藏自治区新记录)。胭螨科Rhodacaridae单刺枝厉螨Dendrolaelaps unispinatus Ishikawa,1977(北京市新记录);匈牙利拟枝厉螨Dendrolaelaspis hungaricus Hirschmann et Wisniewski,1982(山西省新记录)。美绥螨科Ameroseiidae越南美绥螨Ameroseius vietnamensis Micherdzinski,1965(西藏自治区新记录);印度新曲厉螨Neocypholaelaps indica Evans,1963(西藏自治区新记录)。犹伊螨科Eviphididae果洛蜣盾螨Scarabaspis guoluoensis Liu,Gu et Ma,1992(西藏自治区新记录)。植绥螨科Phytoseiidae伪新小绥螨Neoseiulus fallacies (Garman,1948)(西藏自治区新记录);装饰新小绥螨Neoseiulus ornatus (Liang et Ke,1984)(西藏自治区新记录);芬兰真绥螨Euseius finlandicus (Oudemans,1915)(西藏自治区新记录)。     

中国自由生活革螨调查报告(XII) （蜱螨亚纲：中气门目）

通过整理和鉴定,有革螨12科20属32种,其中省区新记录14种。包括厉螨科Laelapidae西宁下盾螨Hypoaspis xiningensis Ma et Lin, 2009（西藏自治区新记录）;湖南下盾螨Hypoaspis hunanensis Ma et Zheng, 2000（云南省新记录）。镰螨科Blattisocidae帕尔巴特手绥螨Cheiroseius parbatensis Evans et Hyatt, 1960（西藏自治区新记录）。裂胸螨科Aceosejidae半裂北绥螨Arctoseius semiscissus (Berlese, 1892)（山西省新记录）。寄螨科Parasitidae邓氏寄螨Parasitus tengkuofani Ma, 1995（西藏自治区新记录）。囊螨科Ascidae安氏囊螨Asca anwenjui Ma, 2003（西藏自治区新记录）。胭螨科Rhodacaridae单刺枝厉螨Dendrolaelaps unispinatus Ishikawa, 1977（北京市新记录）;匈牙利拟枝厉螨Dendrolaelaspis hungaricus Hirschmann et Wisniewski, 1982（山西省新记录）。美绥螨科Ameroseiidae越南美绥螨Ameroseius vietnamensis Micherdzinski, 1965（西藏自治区新记录）;印度新曲厉螨Neocypholaelaps indica Evans, 1963（西藏自治区新记录）。犹伊螨科Eviphididae果洛蜣盾螨Scarabaspis guoluoensis Liu, Gu et Ma, 1992（西藏自治区新记录)。植绥螨科Phytoseiidae伪新小绥螨Neoseiulus fallacies (Garman, 1948)(西藏自治区新记录);装饰新小绥螨Neoseiulus ornatus (Liang et Ke, 1984)（西藏自治区新记录）;芬兰真绥螨Euseius finlandicus (Oudemans, 1915)（西藏自治区新记录）。     

“两型三新”技术在福建送电线路中的应用

阐述了福建省输电线路建设特点,介绍了新技术、新材料、新工艺在福建送电线路中的应用,指出它们符合"资源节约型、环境友好型"的要求.     

新时期新词新义的修辞透视

新时期新词新义的大量出现并得到广泛运用是我国当前语言生活的一个突出现象,其中有相当一部分新词新义是通过修辞方式产生的,比喻等修辞手法已成为新时期新词新义生成的一种充满活力的方式,且这一类新词新义在词义的构成上也具有明显的特征,即词义色彩鲜明,带有丰富的情感体验性和浓烈的形象感,有着典型的民族语言风格.     

"和谐世界"与中国外交新理念

"和谐世界"的构想是新时期我国"和平"外交理念的发展与升华,它把中国近年来在国际上所倡导的新秩序观、新安全观、新发展观和新文明观等有机地联系在一起.在"和谐世界"指引下的中国外交呈现出新的面貌.