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.     

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.     

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.     

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.     

分形特征下降雨诱发砂土泥石流启动机理

利用分形理论计算不同颗粒含量砂土的粒度分维值,开展降雨条件下砂土泥石流启动模型试验,分析试验现象、位移场及含水率变化情况,总结分形特征下泥石流的启动机理。研究结果表明：粒度分维值随细粒含量的增加而增大,坡体发生明显现象的时间越早,泥石流启动的总体历时越长。分维值较大时,以坡表侵蚀破坏为主,坡表整体位移均匀,启动历时长;雨水分布不均匀,滑动带内外含水率差异显著,持水时间长;分维值较小时,以滑坡型破坏为主,启动历时短,产生位移大;雨水运动以渗流为主,土体抗剪强度降低,滑动带内外含水率差异减小,持水时间逐渐消失。分维值大小适中时,以过渡型破坏为主,泥石流启动时位移最小,历时较长,灾害程度最轻。     

苦荞部分营养成分分析及评价

经测定苦荞蛋白质含量为１０．１８％，必需氨基酸含量为４１３．７％ｍｇ／ｇｐｒｏｔｅｉｎ。其限制性氨基酸仅为苏氨酸一种，苦荞蛋白质的氨基酸评分为８８．５分。苦荞矿物质元素含量丰富，其中铁为３２．８，锰为１２．５，锌为２１．４，铬为２．５４，钼为１．６６，锗为４．２，铜为４．３，钙为１２７（单位均为ｐｐｍ）．总黄酮含量为１１０ｍｇ／１００ｇ。苦荞具有很高的营养价值，并对中老年人具有多种预防保健功能，是一种急待开发利用的天然营养保健食品资源。     

Measurements of leucocyte membrane elasticity based on the optical tweezers

A 1-μm in diameter polystyrene bead coated with lectin is trapped by optical tweezers whics is formed by a focused laser beam (740nm).A leucocyte adhered to the bottom of sample cell is chosen to close to the trapped bead.When their stable combination is confirmed,the leucocyte is displaced by moving the sample stage.A“tether”is then formed between the trapped bead and the membrane.The force acting on the tether is measured by a detector equipped on the optical tweezers system.The deformation of the membrane is diverse in different contact conditions.When the contact area is small,the tether is very thin and the force on it is 7.4pN(10^-12N),while the tether is much thicker under a larger contact area and its corresponding force is about 14pN.It is presumed that the latter is related to the deformation of cytoskeleton.     

黑龙江地区小麦麸皮化学组成分析

以我国黑龙江地区的小麦麸皮为原料,对其化学组成成分进行了定量分析,实验测得小麦麸皮中灰分质量分数5．41％、木质素质量分数6．01％、淀粉质量分数25．90％、脂肪质量分数3．45％、戊聚糖质量分数19．42％、综纤维素质量分数46．05％、纤维素的质量分数2．35％及总糖质量分数89．62％,实验结果表明,黑龙江地区的小麦麸皮中综纤维素含量较高,其中以半纤维素为主;戊聚糖含量较高,木质素含量低,易于提取戊聚糖,适应于作为制备功能性食品低聚糖的原料。     

甜荞部分营养成份分析及评价

经测定甜荞蛋白质含量为１０．３４％，必需氨基酸含量为４０８．１ｍｇ／ｇ ｐｒｏｔｅｉｎ。其限制性氨基酸仅为苏氨酸一种，甜荞氨基酸主分为９２分；甜荞矿物质元素含量丰富，锰含量为１０．１４，锌为２１．２，铁为２１．３倍，铬为２．５，钼为２．０４，锗为３．８，铜４．１，钙为１７２；其总黄酮含量为２０ｍｇ／１００ｇ。甜荞有很高的营养价值。并对中老年具有多种作用保健作用，是一种急待开发利用的天然营养保健食品     

RaneyNi电极在葡萄糖、蔗糖电还原上的应用

采用自制隔膜电解槽,首先对阴极材料进行了选择,选出葡萄糖转化率最高的RaneyNi粉电极作为电解阴极。将氢过电位低的RaneyNi粉作为阴极应用到葡萄糖、蔗糖的电解还原中,在pH=10～11,通入电量为1.2F·mol-1,温度为60℃,电流密度为4A·dm-2,糖浓度为0.5mol·L-1最佳工艺条件下阴极电解还原葡萄糖转化率为73%,甘露醇产率为30%;在pH=9,通入电量为1.3F·mol-1,温度为35℃,电流密度为3.0A·dm-2,糖浓度为0.5mol·L-1工艺条件下电解还原蔗糖处理液,转化率为84%,甘露醇产率可达46%。     

中国林产工业的发展前景

21世纪前20年是中国林产工业“黄金发展期”和“矛盾凸显期”。持续强劲的国内外市场需求、城镇化的加速、房屋建筑业作为国民经济支柱产业作用日益明显、家具业趋向于全球化、纸业发展迅速等,给林产工业发展带来了巨大的潜力。中国发展林产工业要由大变强,必须应对众多挑战,如木材原料供不应求、企业规模小、技术水平低等。因此,中国林产工业必须加快原料基地化建设,转变经济增长方式,走循环经济的可持续发展之路;加强研发水平,提高自主创新能力;达到营销理性化,管理现代化和产品品牌化。     

水平井扩眼技术在杜813-H203井的应用

杜813-H203井是辽河油田在超稠油油藏所钻的一口浅水平井。由于该井水平段较长且岩性疏松,井壁掉块严重,井眼多呈台阶状,加之岩屑堆积,增大了后续作业遇卡的风险。为解决测井及后期下套管遇阻问题,根据超稠油油藏的特点采用水平井扩眼技术,清除岩屑床,扩大、修正了原井眼。实测结果表明:该水平段摩擦阻力高于该地层正常钻进水平井的两倍以上,严重影响后续作业。扩眼后整个测井和下套管安全顺利,有效解决了后期作业的复杂情况,提高了固井质量,延长了油井使用寿命。     

无线、无源声表面波传感器系统中检波方案的实现

介绍了无源无线声表面波传感器系统,通过对声表面波的回波窄带信号的分析,阐述了基于数字方式解调回波窄带信号的数学原理.应用matlab仿真对回波窄带信号进行解调,分析相位误差产生的原因,论证了数字正交检波技术的优越性、可行性.在给出仪器系统硬件框图的基础上,根据虚拟仪器技术构建灵活、便携、开发成本低等优点,提出了应用LabVIEW实现数字正交检波技术的硬件方案.     

超声降粘实验研究

通过实验,研究了超声对原油的降粘效果,比较了不同含水率时超声对原油降粘作用的大小,发现原油含水率为32％时,降粘率仅为22．4％。含水率为50％时,降粘率可以达到83％,但此进形成的乳状液不稳定,在原油中掺入表面活性剂,再经超声处理后,形成的乳状液比较稳定,其粘度也较小。