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.     

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.     

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.     

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.     

网络环境下高等学校院系资料室的重新定位

分析了目前我国高等学校院系资料室的现状以及存在的主要问题,重点探讨了网络环境下高等学校资料室的重新定位问题.院系资料室应该把书刊文献移交图书馆管理,建议高校的院系资料室着重灰色文献的管理利用,直接服务于本院系的教学和科研工作.     

Clues to "the Monstrous Joy" of Mrs.MallardIn " The Story of an Hour "

The author of the present article aims to seek plausible explanations as to Mrs. Mallard＇s controversial response to her husband＇s assumed death by sorting out a couple of clues like address forms the heart trouble of Mrs. Mallard, and her repression as well as her strength. The following textual analysis leads to the conclusion that Mrs. Mallard felt the joy of freedom from her husband＇s manipulation and dominance over herself as well as the domestic affairs, over her body as well as her soul at the assumed death of her husband.     

语域学理论和翻译批评——兼评《大卫·科波菲尔》的两个汉译本

所谓翻译批评，是指根据有关理论和观点对翻译思想、翻译活动和翻译作品进行分析和评论，以提高翻译的整体素质、翻译的整体质量和读对译品的鉴赏能力，是翻译研究的组成部分。但如何使翻译批评具有其应有的公正性和客观性，因而达到翻译批评的目的，需要相应的理论作指导。随着语言学理论的层出不穷，越来越多的语言学理论可以应用于翻译批评。本拟将语域学理论和翻译批评结合起来，从新的角度来诠释英国名的语言学家韩礼德的语域学理论，把语域理论的三要素语旨、语场和语式置于语境中进行分析，旨在使翻译批评更理性化、更具客观性与公正性。     

加强党的执政能力建设,构建社会主义和谐社会

加强党的执政能力建设是一个意义重大的战略举措,也是一个构建、创新的系统工程。在构建社会主义和谐社会过程中,加强党的执政能力建设的主要内容可以归结为八个方面。加强党的执政能力建设,要以马克思列宁主义、毛泽东思想、邓小平理论和“三个代表”重要思想为指导,以密切党和人民群众的血肉联系为核心,以促进国家的全面发展为检验标准,以提高党的干部队伍素质为关键,以健全科学的领导体制和工作机制为保证。     

后发地区文化创意产业发展的现状及对策——以龙岩市为例

基于对龙岩市文化创意产业发展现状和存在问题的分析,提出加快龙岩市文化创意产业发展的若干对策与建议,主要包括：深化认识,营造良好社会氛围;科学规划,制定完善政策体系;项目带动,拓展产业空间;形成集群,构建合理产业布局;夯实基础,打造特色文化品牌;集聚人才,提供有力智力保障。     

论校企合作型职业教育集团化办学——以拟组建的"陕西航空高等职业教育集团"为例

从拟组建的"陕西航空高等职业教育集团"的必要性、可行性入手,分析了该教育集团应创新人才培养机制、加强实训实习基地建设、建立西部航空工业高等职业教育师资培训中心、促进教学成果共享、构建职业技能鉴定和专业认证体系等五方面作用,同时建议该集团在领导机制、运行机制、组织架构和保障机制上如何加强;说明组建"陕西航空高等职业教育集团"是高职教育对人才培养的需要,是陕西航空工业发展的需要.     

论校企合作型职业教育集团化办学——以拟组建的“陕西航空高等职业教育集团”为例

从拟组建的“陕西航空高等职业教育集团”的必要性、可行性入手,分析了该教育集团应创新人才培养机制、加强实训实习基地建设、建立西部航空工业高等职业教育师资培训中心、促进教学成果共享、构建职业技能鉴定和专业认证体系等五方面作用,同时建议该集团在领导机制、运行机制、组织架构和保障机制上如何加强;说明组建“陕西航空高等职业教育集团”是高职教育对人才培养的需要,是陕西航空工业发展的需要。     

企业人才识别、吸引和使用问题的哲学思考

在识别人才方面,应用实事求是的心态去看待人才;从发展的角度观察人才;用一分为二的观点辨别人才.在吸引人才方面,既重吸引人才本身,又重人才保护;既重高物质待遇吸引人才,又重精神吸引人才;既重眼前急需的人才,又重未来需要的人才.在使用人才方面,既用人才之长,又用人才之短;既用高文凭的人才,又用高水平的人才;既用专业型人才,又用复合型人才;既用顶尖人才,又用普通人才;既用老人才,又用新人才.     

关联规则挖掘在高校图书借阅统计分析中的应用

把关联规则挖掘与统计分析相结合,应用在图书借阅数据的分析中,从而找出图书与图书之间以及读者和图书之间的一些关联关系,以确定图书采购的合理性,进一步提高图书采购质量。最后给出了相应的建议,作为高校图书馆改进服务时的参考,最终使高校为学生提供更专业更个性化的服务。     

对十二烷氧基苯甲酸合成中催化剂选择的研究

以三苯基膦和DCC为催化剂,正十二醇与对羟基苯甲酸甲酯为原料来催化合成对十二烷氧基苯甲酸.探讨了反应时间,反应温度,催化剂用量对此催化合成反应的影响,从而确定了较佳催化剂,同时采用正交实验分析法,熔点测定法和红外光谱分析法对得出的产品作出了相应的分析.