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.     

国内外信息安全研究现状及发展趋势

阐述了信息安全在国计民生和企业经营中的重要性及信息技术的发展与应用,针对国内外信息安全研究的现状及发展趋势,介绍了安全协议理论与技术、信息对抗理论与技术,重点说明了密码理论与技术、安全体系结构理论与技术、网络安全与安全产品,从社会发展和国家安全角度,指出加大发展信息安全技术的力度已刻不容缓。     

打造变革型科协组织的探索与实践

 科协组织作为党和政府联系科技工作者的桥梁与纽带，应以习近平总书记关于群团组织、科技创新的重要论述和要求作为根本遵循，以“政治性、先进性、群众性”为发展建设根本属性和要求，强化自身建设。从新时代群团特点、发展规律和科协组织自身属性出发，梳理了群团改革要求对科协组织发展建设的要求、科协组织在助力高水平科技自立自强方位中的发展定位，提出要统筹“四个面向”的发展要求，聚焦“四服务”的建设标准，以建设“开放型、枢纽型、平台型”变革型组织为切入点和着力点，将科协组织打造成为红色群团、实干群团、为民群团、数智群团、品牌群团。     

审计监督在反腐倡廉中的地位和作用

从主、客观因素分析了当前存在违反财经法纪现象的主要原因，阐述了审计监督在廉政建设中的地位及其在反腐斗争中的作用，指出应通过审计监督，反馈反腐倡廉的信息，制定反腐倡廉的措施，完善反腐倡廉的制度，特别是加强对领导干部经济行为的约束和监督。     

扩大世界史学科影响促进横向学术交流

世界历史是一门既年轻而又实用性很强的学科,它与时代发展息息相关.如何搞好世界历史的教学与研究,同时又理论联系实际,密切关注当代社会文化发展,是从事该学科教学与研究者必须解决的现实问题.依据“世界现代史与当代社会文化发展”学术研讨会提供的论文,就各专家学者围绕“世界现代史教学与研究”“世界现代史与当代社会发展”“世界现代史与当代文化发展”等问题讨论的观点进行归纳和总结,对扩大学科影响力,促进横向学术交流,拓展史学教育功能具有重要意义.     

基于5W模型的教育认同效果影响因素实证——以高校思想政治教育为例

基于传播学视角，借助5W模型，实证了高校思想政治教育传播过程中传播主体、传播内容、传播渠道、传播对象等因素对思想政治教育认同效果的影响.结果表明，传播者与接受者关系强度、传播者专业能力、传播对象专业能力、传播内容、传播媒介均对思想政治教育认同效果有显著的正向影响，且传播内容、传播媒介、传播者与接受者关系强度对当前高校思想政治教育认同效果的影响最大.因此，当前高校思想政治教育应着力创新并丰富传播内容，系统运用好现代社会化媒介，借助“课程思政”强化教育主体双方的关系，进而促进高校思想政治教育认同的效果.     

基于5W模型的教育认同效果影响因素实证——以高校思想政治教育为例

基于传播学视角,借助5W模型,实证了高校思想政治教育传播过程中传播主体、传播内容、传播渠道、传播对象等因素对思想政治教育认同效果的影响.结果表明,传播者与接受者关系强度、传播者专业能力、传播对象专业能力、传播内容、传播媒介均对思想政治教育认同效果有显著的正向影响,且传播内容、传播媒介、传播者与接受者关系强度对当前高校思想政治教育认同效果的影响最大.因此,当前高校思想政治教育应着力创新并丰富传播内容,系统运用好现代社会化媒介,借助“课程思政”强化教育主体双方的关系,进而促进高校思想政治教育认同的效果.     

试论科技成果商品化、产业化与国际化的法律保护

知识经济时代,加强对科技成果转化的法律保护日趋重要.论述了科技成果商品化、产业化、国际化的法律保护,指出只有如此,才能全面落实科学发展观,实施科技兴国和可持续发展战略,提高科技成果转化率,加强国际合作与交流,真正发挥科学技术第一生产力的作用.     

中亚地区费尔干纳盆地油气地质特征

对中亚地区费尔干纳盆地的地层、沉积和石油地质特征等进行了综合研究.该盆地的烃源岩为下第三系、上白垩统和中下侏罗统的海相与湖相泥岩、页岩和泥灰岩,有四套含油气层系,主要油气储集层为下第三系的滨浅海相和三角洲相砂岩和碳酸盐岩,多套泥岩、膏岩和泥灰岩为区域性和局部盖层,油气主要运移期和聚集期发生在早上新世,油气圈闭和油气田(藏)主要有构造型、构造-地层复合型和地层型等3种,目前油气主要分布在南部边缘构造带的两个含油气区.全盆地最大的油气田--明布拉克油气田的发现,使盆地油气潜力评价价值更高,可为整个中亚地区的油气勘探开发提供借鉴和指导作用.     

地质灾害风险思维培育

 自然条件和人为活动的双重作用导致地质环境日益恶化、地质灾害频发,造成了前所未有的生命和财产损失,而汶川大地震直接促成中国"防灾减灾日"的设立。为了最大限度地减少地质灾害造成的生命财产损失,迫切需要改变地质灾害防治"重灾后整治、轻灾前预防"的传统安全性思维。本文分析了地质灾害防治从传统安全性思维到风险思维转变的必要性和紧迫性,建议加强地质灾害风险评估与管理的相关研究,注重防灾减灾救灾知识的宣传、教育和地质灾害风险思维的培育,特别强调以"防灾减灾日"为契机,不断提高公众的风险思维和防灾减灾意识,构建地质灾害风险文化,最终促成综合防灾减灾救灾能力和水平的提高。     

试论医学科技查新原则和方法

科技查新是通过科技文献检索和对比分析,对科技项目的新颖程度作出判断的信息咨询活动和文献查证工作.本文从科技查新的性质和重要性、科技查新的程序和方法、科技查新咨询与一般文献检索的区别、查新咨询与专家评审的比较、医学科技查新的类型和特点、医学科技项目的新颖性评价与查新结论及科技查新对科技人员的要求等六个方面,试论了医学科技查新原则和方法.