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.     

烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

微生物浸矿技术在我国的研究现状及发展前景

As the world’s second largest economy experiencing rapid economic growth, China has a huge demand for metals and energy. In recent years, China ranks first, among all the countries in the world, in the production and consumption of several metals such as copper, gold, and rare earth elements. Bioleaching, which is an approach for mining low grade and refractory ores, has been applied in industrial production, and bioleaching has made great contributions to the development of the Chinese mining industry. The exploration and application of bioleaching in China are reviewed in this study. Production and consumption trends of several metals in China over the past decade are reviewed. Technological processes at key bioleaching operations in China, such as at the Zijinshan Copper Mine and Mianhuakeng Uranium Mine, are presented. Also, the current challenges faced by bioleaching operations in China are introduced. Moreover, prospects such as efficiency improvement and environmental protection are proposed based on the current situation in the Chinese bioleaching industry.     

不同结构和形态的天然镁硅酸盐:与K反应制备生物柴油的K2MgSiO4催化剂

In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile (which have the same general formula Mg₃Si₂O₅(OH)₄), and talc (Mg₃Si₄O₁₀(OH)₂) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20wt% K and treatment at 700–900°C led to a solid-state reaction to mainly form the K₂MgSiO₄ phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K₂MgSiO₄ formation. All the materials showed catalytic activity for the transesterification of soybean oil (1:6 of oil : methanol molar ratio, 5wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K₂MgSiO₄.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

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.     

体操训赛管理方略之我见

体操的训赛管理工作能否达到预期目标,取决于管理的策略。对此进行了探讨,梳理出“十一规”方略,即：把握规律、精细规划、吃透规则、熟悉规程、狠抓规格、建立规范、严定规矩、巧善规避、勇于规谏、锐意规新、展现规模。     

工科数学教学改革探讨

工科数学教学既要教思想、教方法，又要教做人；既面向全体学生、面向大多数，又要面向两头；要引导学生转变学习观念；同时应加强针对性，注重启发性，提高积极性等，以达到提高学生素质、培养学生能力的目的．     

知识联盟中知识共享的博弈分析

在阐述知识联盟中知识共享的重要性的基础上,分析了知识联盟中的组织在知识共享过程中的收益与成本,指出在知识共享的过程中知识联盟的参与各方均要寻求知识共享成本与知识共享收益的平衡点.运用完全信息动态博弈分析方法,分析了知识联盟中参与各方的知识共享过程,求得子博弈精炼纳什均衡解,从而获取促使联盟各方进行知识共享的条件.对于知识联盟的参与各方知识共享动力匮乏问题提供了解决的思路,有助于知识联盟中的组织实现各自利益的最大化.     

浅谈如何上好新课

上好新课的关键是:一要敢于承担,乐于承担新课,增强对新开课程的兴趣;二要深入钻研教材,认真备好每一堂课,努力实现教学与德育的结合;三要向老教师学习,不断总结教学经验,提高教学艺术;四要重视课后辅导答疑这个环节,做到因材施教,补充课堂教学的不足     

在VB中使用Excel对象的分析

分析了一个在VB中调用Excel对象，实现用VB编程，把原始数据、中间数据及结果都写入Excel文件来求线性方程组解的实例，同时介绍了VB调用Excel，VB把数据写入到Excel中的单元格并对单元格的内容进行格式控制、数值计算，把计算结果从Excel传送回VB的实现方法。     

增强高校网络德育实效性的立体考察

提高高校网络德育的实效性是一项综合性工程,需要开设网络德育课、创新网站德育内容以充分吸引大学生的注意力、创新德育教育手段和途径、建立开放式的互联德育立体网络、加强网络德育队伍的建设、建立和完善网络文化建设,特别是校园网络文化建设的维护机制、引导和鼓励大学生参加实践和加强制度建设,最终形成促进网络德育生态发展的机制。     

实事求是与学校德育

实事求是是学校德育的灵魂。全面认识和处理学校德育中的问题，就要坚持实事求是，反对主观主义，一切从实际出发；反对片面性，辩证地看问题；反对孤立地看德育，在联系中开展工作；反对狭隘封闭，全面客观地评价和推进德育工作。     

浅谈如何提高学生在病理生理学课堂上的主观能动性

病理生理学是一门难教难学的重要医学基础理论课程。课堂是教师教授和学生学习的主要阵地。教师需不断丰富完善自身知识体系，在课堂上运用灵活的教学方法，利用科学先进的教学手段，努力激发学生对病理生理学的学习热情，开发学生学习的主观能动性，提高学生的课堂学习效果，并培养学生将理论应用于实践的临床思维能力。     

《周易》道德修养思想研究

《周易》是最早论述道德修养的著作。从顽强进取，自强不息，谦虚谨慎，勤俭节约，关心民众，以民为本，任人为贤，识贤用贤几方面进行论述。     

路径排序问题基于表面的DNA算法

提出了路径排序问题表面DNA算法三步骤：a．找出两端点的所有链,b．筛选出所有的路,c．得到路序．指出编码问题在DNA计算中的重要性．在算法实现过程中,用保护两端点对应的DNA片段3’端或5’端的办法得到所有的链,并用电泳的方法对链进行排序以及去掉链长大于图权值总和的链;对探针进行生物素标记并且采用观察、记录亮点强度的办法筛选出所有的路;分析实验记录得到路序．将算法推广到最短（长）路问题的不同之处在第三步,即只需分析在表面上排在最前（最后）的DNA链的实验记录就得到最短（长）路．