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.     

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.     

氧化锌矿物浸出渣中铅、锶的提取及动力学分析

NH₄HCO₃ conversion followed by HCl leaching was performed and proven to be effective in extracting Pb and Sr from zinc extracted residual. The mechanism and operating conditions of NH₄HCO₃ conversion, including molar ratio of NH₄HCO₃ to zinc extracted residual, NH₄HCO₃ concentration, conversion temperature, conversion time, and stirring velocity, were discussed, and operating conditions were optimized by the orthogonal test. Experimental results indicate that NH₄HCO₃ conversion at temperatures ranging from 25 to 85°C follows the shrinking unreacted core model and is controlled by inner diffusion through the product layer. The extraction ratios of Pb and Sr under optimized conditions reached 85.15% and 87.08%, respectively. Moreover, the apparent activation energies of Pb and Sr were 13.85 and 13.67 kJ·mol?1, respectively.     

摩擦焊接碳钢（EN24）和镍基高温合金（IN718）的显微组织和力学性能

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel (EN24) and nickel-based superalloy (IN718), and the microstructures of three distinct weld zones—the weld interface (WI)/thermo-mechanically affected zone (TMAZ), the heat-affected zone (HAZ), and the base metal—were examined. The joint was observed to be free of defects but featured uneven flash formation. Electron backscatter diffraction (EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ. Moreover, significant refinement in grain size (2–5 μm) was observed at the WI/TMAZ with reference to the base metal. The possible causes of these are discussed. The microhardness profile across the welded joint shows variation in hardness. The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates. The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.     

汽车暴露面板带有表面条状缺陷的夹杂物分布特征分析:一种定量电解方法

The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface. A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology, size, composition, quantity, and distribution of inclusions in the defect and non-defect zone of automobile exposed panel. The Al₂O₃ inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10 μm. The aggregation sections of the Al₂O₃ inclusions are distributed discretely along the rolling direction, with a spacing of 3–7 mm, a length of 6–7 mm, and a width of about 3 mm. The inclusion area part is 0.04%–0.16% with an average value of 0.08%, the inclusion number density is 40 mm?2 and the inclusion average spacing is 25.13 μm. The inclusion spacing is approximately 40–160 μm, with an average value of 68.76 μm in chain-like inclusion parts. The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002% and 1–2 mm?2, respectively, with the inclusion spacing of 400 μm and the size of Al₂O₃ being 1–3 μm.     

在酸性溶液中加压氧化三价砷离子和二价铁离子

The co-oxidation of As(III) and Fe(II) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150°C. It was confirmed that without Fe(II) ions, As(III) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200°C and an oxygen pressure up to 2.0 MPa. Fe(II) ions in the solutions did have a catalysis effect on the oxidation of As(III), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH·) and Fe(IV) in the oxidation process of Fe(II). The effects of such factors as the initial molar ratio of Fe(II)/As(III), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(III) and Fe(II) were studied. It was found that the oxidation of As(III) was limited in the co-oxidation process due to the accumulation of the As(III) oxidation product, As(V), in the solutions.     

采用超声组装与滚压工艺制备铝–碳纳米管复合材料

This study introduced a novel fabrication of aluminum–carbon nanotube (CNT) composites by employing bulk acoustic waves and accumulative roll bonding (ARB). In this method, CNT particles were aligned using ultrasonic standing wave in an aqueous media, and the arrayed particles were precipitated on the aluminum plate substrate. Then, the plates rolled on each other through the ARB process with four passes. Optical and scanning electron micrographs demonstrated the effective aligning of CNTs on the aluminum substrate with a negligible deviation of arrayed CNTs through the ARB process. The X-ray diffraction pattern of the developed composites showed no peaks for carbon and aluminum carbide. In addition, tensile tests showed that the longitudinal strength of the specimens processed with aligned CNTs was significantly greater than that of the specimens with common randomly dispersed particles. The proposed technique is beneficial for the fabrication of Al–CNT composites with directional mechanical strength.     

活化天然矿石选择性还原二氧化碳为无定形碳

Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H₂ reduction. The temperature-programmed reduction of hydrogen (H₂-TPR) and temperature-programmed surface reaction of carbon dioxide (CO₂-TPSR) were carried out to investigate the processes of oxygen loss and CO₂ reduction. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H₂ atmosphere. Meanwhile, the activity and selectivity of CO₂ reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO₂ reduction at 300°C for 90 min over the activated natural magnetite was 2.87wt% higher than that over the natural magnetite.     

火电厂电气系统融入DCS模式探讨

结合国内火电厂电气监控系统(ECS)接入DCS的实际状况,详细分析了硬线接入方式、保留部分硬接线的通信接入方式的网络结构、接入信息、控制方式及各接入模式的特点,并在ECS的发展中探讨了全通信接入的方式.     

伺服控制系统与变频控制系统在油田注水系统应用中的对比分析

由于伺服控制系统具有准确、精确、快速定位的特点,在油田注水系统有着潜在的应用市场。本研究主要根据在敖古拉作业区进行的现场试验对于同工况运行的30kW注水电机应用伺服控制系统后与原变频系统的对比,分析伺服控制系统的适应性。通过实验得出,同样工况条件下伺服控制系统要比变频控制系统节能7.75%,供水压力波动范围小,压力变化调整时间短。     

有限时间收敛控制与时间最优控制性能指标分析

讨论了有限时间收敛控制与时间最优控制问题，分析了有限时间收敛控制及时间最优控制各项性能指标，探讨利用有限时间收敛控制的方法通过选择适当的控制及参数，求解最优控制的近似解.最后利用二阶及三阶系统举例具体说明了分析结果.     

多模态控制系统研究

提出的多模态控制系统主要是基于变结构、自适应、分级模糊控制策略。首先 ,根据被控对象性能指标构造模糊变量集 ,再由该变量集构造模糊控制规则集并由此改变分级模糊控制的控制参数。在此基础上该系统辅以变结构及自适应控制使控制系统在大幅度改变给定值 ,及系统参数大幅度变化时 ,以改善系统控制品质。该系统实际应用于电加热渗碳炉的温度控制并收到较好的控制效果。     

交通信号灯智能控制系统设计与实现

研究了运用PLC技术的交通信号控制系统，用简洁的软硬件使其智能化程度更高。采用PLC与计算机之间的通讯链接技术，完成交通对象的复杂控制。并运用模糊控制原理，将人的控制经验及推理过程纳入系统自动控制当中，使车辆行驶和道路导航实现智能化。     

楼宇设施计算机管理控制系统

本文介绍楼宇计算机管理控制系统的结构，说明了构成该系统的各控制模块及其作用，给出了部分主要的实例，说明如何完成控制的．     

控制系统的输入对系统稳定性的影响

给出一种可用于时变与非线性控制系统稳定性的判别方法。方法将控制系统的输入变换为控制系统的时变参数,研究输入对控制系统稳定性的影响。     

浅谈电算化会计系统的内部控制

根据电算化会计系统对内部控制的三大特殊要求,计算机会计系统的内部控制制度可分为：对系统开发、发展的控制,对计算机会计系统各个部门的管理控制,对计算机会计系统日常运行过程的控制。     

嵌入式喷印机控制系统

 控制系统需要完成数据传输、打印控制、电机精确定位等功能,是整个喷印机系统中最为关键的组成部分,控制系统的优劣直接影响到喷印机喷印的速度、精度和质量。基于嵌入式技术,本文设计了一种喷印机控制系统,采用华恒科技HHARM2410-Integration-R2嵌入式Linux开发板作为控制核心,并利用网络传输打印数据,使喷印机具有喷印速度快,分辨率高,电机运行平稳,电机定位精确、系统运行可靠性等优点。同时,系统利用uClinux的强大的网络功能实现了运行在嵌入式上的小型Web服务器,通过浏览器访问该嵌入式喷印机控制系统上的Web服务器设置和提取运行时的数据,进行设备的维护与管理。本控制系统已经投入实际使用,相对于上一代基于单片机的控制系统,具有稳定性好、故障率低、喷印速度快、单位时间内喷印面积更大等优点。由于采用了振荡频率更高的喷头,系统相对于上一代控制系统还具有更高的分辨率和喷印精度。     

浅谈上市公司内控制度的设计

分析了上市公司内部控制的薄弱现象及原因,从制度控制、机制控制和内部会计控制方面论述了上市公司内控制度的设计,指出正确发挥制度控制、机制控制和会计控制的作用,上市公司就一定能取得实质上的进步.