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.     

小额诉讼程序与速裁程序的比较及立法选择

小额诉讼程序和速裁程序皆为我国民事诉讼简易化程序改革之产物,两者既有相同之处又有相异之点。从司法改革趋势来看,速裁程序日益凸显其实践价值,小额诉讼程序则逐渐式微。但是,不能因速裁程序之＂兴盛＂,小额诉讼程序之＂没落＂,而在倡举速裁程序之时,完全摒弃小额诉讼程序之功能性价值。毕竟,小额诉讼程序与速裁程序并无本质上的冲突和矛盾,两者均有值得引鉴的内在机制。所以,改进和整合小额诉讼程序和速裁程序,将小额诉讼程序置于速裁程序之中,成为速裁程序一部分更为合理。     

德、日、台民事诉讼程序转换制度之比较与借鉴

在以简化诉讼程序为主流的背景下,简易程序成为各国普遍关注的焦点的同时,简易程序与普通程序的相互转换问题也日益凸显,我国也不例外。鉴于我国目前的立法和实践在程序转换问题上还存在许多不足,笔者通过考察其他国家（主要是大陆法系国家）的相关规定,观察我国的司法实践,对我国程序转换中几个重要问题的构建或完善提出初步设想。     

有偏工序能力系数C_（PK）和当量工序能力系数C_P＇的分析与评价

本文针对产品制造过程中，同一工序生产的产品质量特性值的分布中心与工序技术要求的公差中心发生偏移的情况，对有偏工序能力系数ＣＰＫ和当量工序能力系数ＣＰ’进行了分析，指出了有偏工序能力系数在理论上存在的问题以及在实际应用中的局限性。     

民事诉讼审前准备程序研究

对审前准备程序及其程序价值进行分析厘定,认为我国现有的民事诉讼审前准备程序立法容易导致法官预断,职权色彩过重,缺乏对当事人诉讼权利的保护,未赋予审前准备活动程序上的效力。指出目前对于审前准备程序的规定存在四方面问题：对证据交换内容的规定过于原则化;当事人收集证据的保障措施不完善;审前准备程序适用范围过窄;缺乏对答辩失权的规定。提出我国构建审前准备程序应遵循的原则及措施,通过扩大简易程序的适用范围、设置答辩失权制度、完善现有证据制度、建立准备法官制度、完善调解及和解制度等途径,健全我国民事诉讼审前准备程序。     

混料工艺对Al+Fe2 O3铝热剂反应原料性能与微观形态的影响

采用双螺旋和球磨两种混料方式,研究不同混料时间对铝热剂性能及颗粒微观形态的影响.结果表明混料过程中球磨混料颗粒平均粒度比双螺旋混料大,松装密度比双螺旋混料小,在双螺旋混料4 h,球磨混料6 h时混合最为均匀,球磨混料物料均匀性好于双螺旋混料.微观形态显示双螺旋混料颗粒主要以Fe2O3粉末团聚形成,球磨混料颗粒以Fe2O3和Al接近化学配比团聚在一起长大形成.     

我国行政诉讼简易程序研究

简易程序是一种相对于普通程序而言较简便易行的审判程序,其因自身的内外部正当性而成为平衡诉讼中公平与效率的一种捷径。而长期以来,我国行政诉讼中却排斥简易程序的适用。我们应当在简易程序正当性的基础上构建适宜的行政诉讼简易程序。     

大衍术算法的推进和简化研究

大衍术是中国中世纪数学家的一项世界领先的创造。秦九韶在其所著的《数书九章》中首创了大衍术的算法。启发了后代学者对大衍术算法的进一步研究和改进。但在这些算法中,几乎没有一种是用珠算来解决的。本文给出了该算法的珠算程序,通过比较研究可以看出,在所述的各种算法中,这是最简捷的,而且更容易搬到计算机上。     

单独提起行政赔偿程序的制度性障碍及其克服

行政赔偿的目的在于恢复受害人受损的合法权益,但缺乏程序保障的权利无法得以实现.单独程序可以在最大范围内实现受害人的权利救济,其功能的发挥取决于受害人获取司法救济的渠道是否通畅.现行单独程序在制度上的不尽完善和在实践中的不当操作,已严重影响了其作为权利救济制度应有的功能.问题解决的思路是以权利保障和争议解决为中心,从方便受害人行使赔偿请求权的角度对现行制度予以修改.     

SQL SERVER扩展存储过程实现机制及应用方法初探

介绍SQL Server扩展存储过程的特点及其实现机制,并用一个程序实例阐述了在VC＋＋6．0开发环境下生成SQL Server扩展存储过程动态库框架、编写SQL Server扩展存储过程代码、添加SQL Server扩展存储过程到数据库中及调试SQL Server扩展存储过程的方法和步骤。     

罗马-教会法民事诉讼程序的特征及其历史地位

罗马-教会法民事诉讼程序在诉讼程序法中被称为“欧陆诉讼程序之母”,具有重要的历史地位。它缔造了现代民事诉讼程序的雏形,是诉讼程序理性化的开端。罗马-教会法民事诉讼程序以书面程序为原则、采行间接审理模式、严格的形式证据制度、诉讼程序断续迟延、发明了简易程序,形成正式-简易二元程序结构。它是英国衡平法诉讼程序及海事诉讼程序的渊源,还促进欧陆诉讼程序的统一和诉讼法学的形成。