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.     

陕西延川黄河蛇曲国家地质公园旅游资源研究与建设构想析

陕西延川黄河蛇曲是发育在晋陕峡谷中的大型蛇曲群体,完整系统地保留了黄河蛇曲形成、演化过程的地质遗迹,本文通过对该国家地质公园旅游资源的进行调查和系统研究的基础上,采用定性与定量相结合的方法,依据旅游资源的评定体系和评定方法,对陕西延川黄河蛇曲国家地质公园的地景及人文旅游资源质量、区域环境质量和旅游开发利用条件进行评价,表明陕西延川黄河蛇曲国家地质公园达到国家级资源质量标准。并根据陕西延川黄河蛇曲国家地质公园适宜发展地质旅游的特点,提出了建设该国家地质公园的具体建设构想。     

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.     

96例肝硬化并食管胃底静脉曲张分析

目的了解肝硬化患者食管胃底静脉曲张程度与门、脾静脉内径的关系和出血情况。方法分析96例失代偿期肝硬化患者的临床资料,包括胃镜检查所见食管胃底静脉曲张程度,腹部B超所测门静脉内径、脾静脉内径。比较出血组与非出血组门静脉主干、脾静脉内径及其与食管静脉、胃底静脉曲张程度的相关性。结果肝硬化出血组门静脉主干和脾静脉内径均比非出血组增宽（P〈0.01）。食管静脉曲张严重程度与门静脉主干内径正相关（rs=0.332,P=0.001）,胃底静脉曲张严重程度与门静脉主干内径正相关,但无统计学意义（rs=0.184,P=0.073）。食管静脉曲张严重程度与脾静脉内径正相关（rs=0.281,P=0.006）,胃底静脉曲张严重程度也与脾静脉内径正相关（rs=0.330,P=0.001）。结论通过腹部B超测量门静脉、脾静脉增宽程度可判断门脉高压和食管/胃底静脉曲张程度,并预测食管/胃底静脉曲张破裂出血的风险。     

新时代弘扬科学家精神的若干思考

 新时代建设世界科技强国、推动高水平科技自立自强,对广大科技工作者提出了更高要求,必须弘扬科学家精神,铸就新的创新丰碑和新的精神特质。在梳理科学精神和科学家精神发展历程的基础上,分析了新时代弘扬科学家精神的重要意义。针对多部门推进、科学家精神传播体系、作风学风建设、科学共同体微生态建设面临的问题与挑战,探讨了新时代弘扬科学家精神的基本路径：健全部门机构协同推进机制;完善科学家精神传播体系;筑牢作风学风建设底线要求;加强科学共同体微生态建设。     

儒学发展与中国古代文学思潮

儒学在其发展过程中出现过许多学术流派或学术思潮，以此为标志而呈现出明显的阶段性。儒学发展的每一段落，甚至包括其分化和遭到叛逆的段落，均对中国古代文学产生了广泛而深刻的影响或推动，导致其时古代文学思潮、热潮或特定创作倾向的产生。这种情况可大致归纳为：孟、荀尚气劝学与宏辩文学思潮；两汉经学与大赋高潮；魏晋玄学与文学尚简嗜奇热潮；两宋理学与文学尚理倾向；明代理学发展与文学思潮的演变，具体为阳明心学与小说浪漫化思潮、泰州学派与小说世俗化倾向；乾嘉学风与小说炫耀才学热潮。作为中国传统文化中极重要的两个系统，儒学与中国古代文学的这种特定联系，成为中国古代文化发展史的重要现象，具有丰富的文化底蕴和文学理论蕴涵。     

“A。就是说，B”类句式的语用、篇章考察

从语用和篇章的角度考察“A。就是说,B”这类句式中A和B的表达差异及其成因和对B的表达方式与内容的理解问题。先从正面和反面两个表达角度即肯定和否定的表现形式对句式进行分类。然后,又根据A和B在表达方式上的差别或两者之间的关系分出各种小类。通过分析,认为肯定和否定形式使用的原因,与句式的使用意图和使用缘由直接相关。对于B的表达方式和内容的理解,必须联系上文语境和说话人的意图。     

贵阳市乌当区砂石资源的开发利用与保护规划

作为建筑用砂石原料的石灰岩、白云岩在贵阳市乌当区境内分布广泛,资源储量丰富。介绍了贵阳市乌当区的经济、资源状况及砂石资源开发利用现状,阐述了砂石资源开发利用与保护规划取得的成就及面临的问题,提出了砂石资源开发利用及保护规划的目标与指标。     

基于可拓学的大学生网络游戏成瘾防治效果评价研究

针对地方高校大学生网络成瘾防治问题,建立大学生网络游戏成瘾防治效果评价的分级指标体系,采用梯度等级量化方法,量化表示调查结果测评参数;进一步运用可拓学的聚类分析方法,通过物元定义及转换法,分析影响防治效果的各个因素重要程度,并且从网络游戏成瘾大学生、家长、辅导员老师多个角度进行调查,定量地测算出大学生网络游戏成瘾防治综合效果;最后,通过深入分析影响大学生网络游戏成瘾防治评价指标各因素的优缺点,结合大学生成长成才的目标和现实需求,并分析实施措施后大学生游戏成瘾的变化趋势和纠正效果,以此来不断改进防治实施措施,降低大学生网络游戏成瘾的比例,达到更佳的网络游戏成瘾防治效果,契合教育教学改革的需要。     

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.