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.     

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.     

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.     

含钛高炉炉渣微波合成碳化钛及其介电性能测定

The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery; it can alleviate the environmental pressure caused by slag stocking. The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method. Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed. The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.     

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.     

精准神经外科学的研究进展

 精准医学,指根据个体的基因组学、生活环境、生活习惯等信息,对患者进行个体化疾病诊疗和预防的医学方式。受益于基因组学、影像组学的最新成果,手术、放疗中新技术的出现,精准医学时代的到来为神经外科学发展带来巨大机遇。本文从精准的解剖学定位、精准的脑功能定位、精准手术、神经系统肿瘤的精准诊疗、非肿瘤疾病的精准治疗等方面,阐述精准神经外科学的最新进展。     

野生黄缘闭壳龟资源分布与濒危机制研究

黄缘闭壳龟属世界珍稀濒危物种,中国重点野生保护动物.20世纪70年代前野生黄缘闭壳龟曾广泛分布于中国的河南、安徽、湖北、湖南、浙江、江苏、广西、台湾等省和琉球群岛,野生资源十分丰富,仅河南信阳大别山区的分布面积多达39万hm~2,野生种群数量约40万只.但自20世纪80年代后,随着盗猎强度的加剧,黄缘闭壳龟的分布区和栖息地遭到地毯式的搜索,猎捕手段的多样化及其过度猎捕致使黄缘闭壳龟野生资源日益枯竭.目前只在河南大别山区、安徽皖南山区、安徽皖西山区等地还有少量野生个体生存,稳定的黄缘闭壳龟野生种群仅分布于台湾和琉球群岛.导致黄缘闭壳龟野生资源濒危的原因主要是其性成熟周期长、种群繁殖力低、栖息地遭受干扰破坏等因素,另外,人类贪婪无尽地对其野生资源的索取是导致黄缘闭壳龟自然种群濒危灭绝的重要原因.加强黄缘闭壳龟保护区的建设与管理,加大打击盗猎行为,提高公众的保护意识,建立生态补偿机制,开展自然种群的恢复与重建是拯救黄缘闭壳龟濒危灭绝的有效措施.     

城市声景观

简要叙述了一系列关于城市声景评价、模拟以及预测的综合研究，这些研究特别着眼于城市公共开放空间，其中声景评价重点研究各种声学、环境、社会、人口、心理、文化和行为因素对声景质量的影响，以及描述声景的主要因素，这部分研究主要建立在一系列在欧洲和中国进行的声景调查的基础上．发展了计算小尺度城市区域的声场模拟模型，包括基于声能的虚声源法、声线追踪法、radiosity法、声线追踪／radiosity综合法，以及城市声场可听化技术，然后利用这些模型对小尺度城市区域的声场基本特征以及建筑设计和城市规划的作用进行了分析．最后，运用人工神经网络技术以及序数逻辑回归技术，提出了一个预测声景质量的模型工具，其输入包括设计的空间和声源情况以及使用者的社会、人口及行为特点等．     

苹果园夏季大型土壤动物群落结构与组成

 为了解洛川苹果园夏季大型土壤动物的群落多样性,并为进一步开展陕北经济林地区土壤动物学方面的研究提供基础资料。本研究利用对角线五点法采样法和国际通用的手拣法对洛川苹果园示范园和常规园大型土壤动物进行采样。共获得动物134只,隶属4门6纲9目。优势类群为咀刺目、正蚓目、鞘翅目;常见类群为双翅目、鳞翅目、膜翅目、柄眼目等。其中咀刺目、正蚓目、鞘翅目占总捕获量的比例最大,分别为37.31%、28.36%、12.69%,共占总捕获量的78.57%,构成了群落的主要框架。在洛川苹果园示范园和常规园中,大型土壤动物的表聚性比较明显;示范园大型土壤动物的类群数、多样性指数、均匀性指数和丰富度指数均高于常规园,但个体数和优势度指数低于常规园。由此可知,示范园土壤动物群落物种丰富,结构复杂,类群数量分布均匀,显示了大型土壤动物对不同果园土地利用方式和管理措施的响应情况。     

海洋脊椎动物体内的铜、铁、锌、硒

本文所设计的金属中,铜、铁、锌是海洋无脊椎动物体内的必需元素,它们受到严格的代谢调节,因此这三种元素不大可能产生严重的污染效应。硒是一种稀有元素,也是海洋无脊椎动物体内的不可缺少的元素。同时本文还阐述了它们的生态效益、化学状态,及它们和其他种金属相互关系联及拮抗作用。还有环境工业污染对这些元素的影响。     

基于3G技术的电动车报警定位系统研究

结合3G技术在远距离监控、数据采集、GPS定位、无线报警等领域的应用,设计了基于3G技术的电动车报警定位系统,分别对系统的单片机电路、通讯电路、卫星定位电路进行了设计,实际使用情况表明,系统工作准确及时,最大限度降低电动车被盗几率。     

论新时期我国民主政治建设的理论创新和实践

新时期中国共产党通过理论创新确立了中国特色社会主义理论体系,产生了民主法制、依法治国、政治文明、以人为本、和谐社会等新的思想观念,为中国民主政治发展作了方向性和理论性指导。在实践中,按照适应经济发展和经济体制改革的要求,同时适应公民政治参与积极性提高的要求,中国共产党领导人民,在制度建设、民主执政、党内民主、人权保障等方面深化政治体制改革,不断探索民主政治建设的实践路径。国情性、时代性、互动性、同一性、渐进有序性是改革开放以来我国民主政治建设的基本经验。     

半挥发性有机污染物的人体暴露评估方法

 半挥发性有机物（SVOCs）的人体暴露研究已成为环境研究领域的热点。传统的人体暴露评估方法（如血液组织检测等）具有侵入性、复杂性、成本高、样品难获得等缺点。新型被动采样方法以其非侵入性、简单易行、易于接受等优点逐渐受到了广泛关注。总结了非饮食人体暴露评估的方法，重点介绍了人体暴露评估的新兴被动采样技术，包括硅胶腕带、硅胶胸针、手擦拭样、衣服等，其中硅胶手环和硅胶胸针以其廉价易得、易于被接受和稳定性好等优点逐渐得到了广泛应用；此外，利用衣服作为SVOCs人体暴露研究的手段，也具有良好的发展潜力和应用前景。     

基于IRP的Windows设备驱动程序文件操作的实现

文件是数据存储的基础,处于Windows操作系统内核中的设备驱动程序,对文件系统的访问不像应用程序那样方便。文章介绍了Windows设备驱动程序通过建立自定义I/O请求包(IRP),并将IRP发送到文件系统驱动程序的方式,实现对文件的内核级操作的方法,该方法可实现文件建立、读、写、删除和改名等功能。文章给出了基于微软设备驱动程序开发工具实现的IRP包的建立、发送和完成的源码。     

微生物发酵对川乌、附子中生物碱含量的影响

探讨了微生物发酵对川乌、附子中新乌头碱、乌头碱、次乌头碱含量的影响。将菌种以孢子悬液的形式接入灭菌生川乌、生附子、制川乌、制附子药材中,30℃固态发酵培养7 d提取生物碱,对照组为未发酵药材。采用高效液相色谱法测定其含量。研究发现发酵药材中新乌头碱、乌头碱、次乌头碱质量分数明显低于原药材:生川乌中新乌头碱、乌头碱、次乌头碱的质量分数分别为0.1390%、0.0195%、0.0320%,而发酵生川乌中分别为0.0231%、0.0039%、0.0117%;生附子中新乌头碱、乌头碱、次乌头碱的质量分数分别为0.2750%、0.0670%、0.0550%,而发酵生附子中分别为0.0633%、0.0552%、0.0291%;生川乌+附子中新乌头碱、乌头碱、次乌头碱的质量分数分别为0.1395%、0.0075%、0.0078%,而发酵生川乌+附子中分别为0.0202%、0.0022%、0.0026%。该结果表明微生物发酵有助于降低川乌、附子中有毒生物碱的含量。