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Effect of reductant type on the embedding direct reduction of beach titanomagnetite concentrate

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International Journal of Minerals,Metallurgy and Materials 2019年第2期26卷 152-159页

作者： Yong-qiang zhao Ti-chang Sun hong-yu zhao Chao Chen Xiao-ping Wang Key Laboratory for High-Efficient Mining and Safety of Metal Mines Ministry of Education University of Science and Technology Beijing School of Civil and Resource Engineering University of Science and Technology Beijing

Iron and titanium were recovered from beach titanomagnetite(TTM) concentrate by embedding direct reduction and magnetic separation. The reduction products and the effects of the reductant type and reduction temperature on the reduction behavior were investigated. The results showed that the reduction of TTM concentrate was strongly related to the gasification reactivity of the reductant. Bitumite presented a better product index than wheat-straw biochar and coke, mainly because the gasification reactivity of bitumite was better than that of the other reductants. In addition, high temperatures were not beneficial to embedding direct reduction because of the emergence of a molten phase and iron-joined crystals, which in turn reduced the diffusion rate of the reducing gas and impeded the reduction reaction in the central area of the roasted briquette. The use of bitumite as the reductant at a C/Fe molar ratio of 1.4 and a reduction temperature of 1200°C for 120 min resulted in direct-reduction iron powder assaying 90.28 wt% TFe and 0.91 wt% TiO_2 with an iron recovery of 91.83% and titanium concentrate assaying 46.01 wt% TiO_2 with a TiO_2 recovery of 91.19%. Titanium existed mainly in the form of anosovite and ilmenite in the titanium concentrate.

关键词： beach titanomagnetite concentrate embedding direct reduction magnetic separation reductant reduction temperature

Microscopic Phase-Field Simulation for the Influence of Interatomic Potential on the Precipitation Process of Ni_(75)Al_(14)Mo_(11) Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第10期29卷 975-984页

作者： Qing-Shuang Ma yu-Chun Jin yu-hong zhao Huai-Ming Sui Pu Zhang School of Materials Science and Engineering North University of China Yangzhou Feng Ming Metal Products Co. Ltd

Abstract The process of γ＇ phase precipitating from Ni75Al14MO11 is studied by a computational simulation technique based on microscopic phase-field kinetics model. We studied the phase transformation with the purpose of clarifying the influence of the nearest interatomic potential V Ni-Al （the nearest interatomic potential） on the precipitation process of γ＇ phase. The result demonstrates that there are two kinds of ordered phases, respective Llo and L12 in the early stage, and Llo phase transforms into L12 phase subsequently. For L12 phase, Ni atoms mainly occupy α site （face center positions）, while Al and Mo atoms occupy fl sites （the vertex positions）. When VNi-Al is increased by 10 MeV, the occupation probability of Ni atoms on α sites and Al atoms on β sites are enhanced. Enhanced VNi-Al facilitates clustering and ordering of Al atom, which promotes the formation of the γ＇ phase. At last, the simulation result was discussed by employing the thermodynamic stability.

关键词： Interatomic potential Phase transformation Microscopic phase-field Occupation probability

Phase-field simulation of tip splitting in dendritic growth of Fe-C alloy

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Journal of Iron and Steel Research International 2017年第2期24卷 171-176页

作者： Yong-sheng Kang yu-chun Jin yu-hong zhao Hua Hou Li-wen Chen Material Science and Engineering Institute North University of China Taiyuan 030051 Shanxi China

Two types of dendrite tip splitting including dendrite orientation transition and twinned-like dendrites in Fe-C alloys were investigated by phase-field method. In equiaxed growth, the possible dendrite growth directions and the effect of supersaturation on tip splitting were discussed; the dendrite orientation transition was observed, and it was found that the orientation regions of anisotropy parameters were reduced from three to two with increasing the supersaturation, which was due to the effect of interracial anisotropy controlled by the solute in front of S/L interface changing with the increase of supersaturation. In directional solidification, it was found that the twinned like dendrites were formed with the fixed anisotropy couples and no seaweed dendrites were observed; these were concluded from the results of competition between process anisotropy and inherent anisotropy. The formation process of twinned-like dendrite was investigated by tip splitting phenomenon, which was related to the chan ges of dendrite tips growth velocity. Then, the critical speed of tips splitting and solute concentration of twinned-like dendrites were investigated, and a new type of microsegregation in Fe-C alloys was proposed to supplement the dendrite growth theories.

关键词： Tip splitting Fe C alloy Interracial anisotropy Dendritic growth

Phase-Field Lattice-Boltzmann Study for α-Mg Dendrite Growth of Mg-5wt%Zn Alloy with Forced Convection

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Acta Metallurgica Sinica(English Letters) 2023年第11期36卷 1791-1804页

作者： Wei-Peng Chen Hua Hou yun-Tao Zhang Wei Liu yu-hong zhao School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan030051China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang110004China

Melt flow can significantly change the transport of heat and solute,dendrite *** this work,a phase-field lattice-Boltzmann model was developed to studyα-Mg dendrite growth of Mg-5wt%Zn alloy with forced *** show that the existence of forced convection and overlap of thermal and solute fields makes thermal and solute fields distribution ***,the symmetry of dendrite morphology is *** solid temperature and concentration of the downstream dendrite tip front with forced convection are higher than that without forced convection,while the concentration of the upstream dendrite tip front is *** solute transport through melt flow will be hindered by developed *** flow velocity increase,the upstream temperature gradient and thickness of the downstream solute enrichment layer increase gradually,while the downstream temperature gradient and thickness of the upstream solute enrichment layer decrease ***,the upstream dendrite tip velocity will increase gradually,while the downstream dendrite tip velocity will decrease at first and then *** study is helpful to establish the relationship betweenα-Mg dendrite growth and melt flow,which is beneficial to understand the role of melt flow on dendrite morphologies.

关键词： Dendrite growth Mg-Zn alloy Forced convection Phase-field method Lattice-Boltzmann method

Expression of c-Fos protein and nitricoxide synthase in neurons of cerebral cortex from fetal rats in hypoxia and protective role of Angelica sinensis

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Neural Regeneration Research 2006年第1期1卷 74-77页

作者： hong yu hongxian zhao yuling Wu Department of Histology and Embryology Luzhou Medical Collegeof Sichuan Province Luzhou 646000 Sichuan Province China

BACKGROUND： Both c-Fos protein and nitricoxide synthase （NOS） have been used as general indexes in relative research about neurons, but it is lack of reports that c-Fos protein and NOS are applied synchronously to study the neurons of hypoxic fetal rats in uterus. OBJECTIVE： To study the effect of hypoxia in uterus on the expression of c-Fos protein and NOS in neurons of cerebral cortex from fetal rats and whether Angelica sinensis has the protective effect on these neurons in hypoxia. DESIGN： Randomized control experiment.SETTING ： Department of Histology and Embryology, Luzhou Medical College.MATERIALS ： Twelve adult female Wistar rats in oestrum and 1 male Wistar rat with bodymass from 220 to 250 g were chosen. Parenteral solution of Angelica sinensis mainly contained angelica sinensis, 10 mL/ampoule, was provided by Department of Agent of the Second Hospital Affiliated to Hubei Medical University （batch number： 01062310）. METHODS ： This experiment was completed in the Department of Histology and Embryology of Luzhou Medical College from September 2003 to June 2004. ①Twelve adult female Wistar rats in oestrum and 1 male Wistar rat were housed in one rearing cage. Vaginal embolus was performed on conceive female rat at 8： 00 am next day. On the 15^th conceiving day, all conceiving rats were divided randomly into three groups： control group, hypoxia group and Angelica group with 4 in each group. Rats in hypoxia group and Angelica group were modeled with hypotonic hypoxia in uterus. Angelica group： Rats were injected with 8 mL/kg Angelica sinensis injection through caudal veins before hypoxia. Hypoxia group： Rats were injected with the same volume of saline. Control group： Rats were not modeled and fed with normal way. ② Twenty embryos of rats were chosen randomly from each group and then routinely embedded in paraffin. Paraffin sections were cut from the brain of embryos to anterior fontanelle. Double-label staining was used to detect the expression of nN

关键词： Fos Expression of c-Fos protein and nitricoxide synthase in neurons of cerebral cortex from fetal rats in hypoxia and protective role of Angelica sinensis

Microalloying Effect of Sn on Phase Transformation During Heat Treatment in Mg–Y–Zn–Zr Alloys

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 550-558页

作者： Pei-Lin Zhang yu-hong zhao Ruo-Peng Lu Zhi-Bing Ding Hua Hou School of Materials Science and Engineering North University of China

The microstructure and mechanical properties of the as-cast and heat-treated Mg-4.6 Y-2.5 Zn-0.6 Zr-x Sn(x = 0, 0.2 and0.5 wt%) alloys were investigated in this work. The results showed that the eutectics have been refined with 0.2% Sn addition and it has no effect on the phase category of the alloys. However, Sn3 Y5 phase was found in 0.5% Sn-added *** heat treatment at 520 °C, the transformation of the long-period stacking ordered(LPSO) phase takes place in the Mg-Y-Zn-Zr alloy, but the transition is not completed in the alloys containing Sn. In addition, during the heat treatment, the mechanical properties of Sn-free alloys are significantly improved, and the strength of alloys containing Sn does not change much. Through observation and analysis of the microstructure and mechanical properties, it is found that Sn addition hinders the process of a0-Mg ? a-Mg ? 14 H and the process is the key to the transition of 18 H-LPSO to 14 H-LPSO.

关键词： Long-period stacking ordered(LPSO) phase Microstructure Heat treatment Phase transformation

Gastric and intestinal ectopic pancreas: Two case reports

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World Journal of Clinical Cases 2023年第29期11卷 7221-7226页

作者： Huan Zhang hong-yu zhao Feng-Hua Zhang Wei Liang Department of General Surgery Hebei General HospitalShijiazhuang 050051Hebei ProvinceChina

BACKGROUND Ectopic pancreas may be unfamiliar to many people because it is rare and difficult to ***,this disease is highly susceptible to misdiagnosis and missed *** this article,we report two cases of pancreatic heterotopia in the gastric sinus and small intestine,respectively,both of which were confirmed by histopathological *** SUMMARY The first patient was a 43-year-old female which reported abdominal distension for 2 *** second was a 67-year-old female who experienced intermittent epigastric discomfort for 15 *** both cases,there was no confirmed preoperative examination,and the postoperative pathology indicated the presence of ectopic *** The diagnosis of ectopic pancreas is difficult,and is often prone to misdiagnosis and the possibility of being *** laboratory tests and imaging tests should be carefully evaluated before surgery to achieve early detection,early diagnosis and early treatment.

关键词： Gastric Intestinal Ectopic pancreas Case report

Model for Influences of Magnetic Fields on Intracellular Calcium Oscillations

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Communications in Theoretical Physics 2009年第7期52卷 168-172页

作者： ZHANG yu-hong ZHAN Yong zhao Tong-Jun CHEN Ya-Fei yuAN Chang-Qing School of Sciences Hebei University of Technology Tianjin 300130 China

Based on the model of the two calcium stores developed by Goldbeter, the influence of external magnetic field on the calcium concentration has been discussed. We believe that the cell membrane is a major site of interaction for extremely-low-frequency （ELF） electromagnetic fields, and the permeability of ions can be changed with the changing electromagnetic fields. It is shown that magnetic field initiates intraeellular calcium oscillation with a threshold in flux density, and that the calcium oscillations do not occur if the density of magnetic field is below the threshold. The results of theoretical calculation are consistent with that of the experiment. The intracellular free calcium concentrations of different cells exposed to the same magnetic fields are different from each other. It is indicated that the different behaviors such as oscillation, rise and invariability of calcium concentration are associated with the sort of cells.

关键词： calcium oscillation magnetic fields calcium concentration

BoxCox multi-output linear regression for 10.7 cm solar radio flux prediction

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Research in Astronomy and Astrophysics 2021年第4期21卷 225-234页

作者： Rui-Fei Cui Ya-Guang Zhu Huan Zhang Ri-Wei Zhang hong-yu zhao Zheng-Lian Li State Key Laboratory of Astronautic Dynamics Xi’an 710043China Beijing Information and Communication Research Center Beijing 100840China

We consider the problem of predicting the mid-term daily 10.7 cm solar radio flux(F10.7),a widely-used solar activity index.A novel approach is proposed for this task,in which BoxCox transformation with a proper parameter is first applied to make the data satisfy the property of homoscedasticity that is a basic assumption of regression models,and then a multi-output linear regression model is used to predict future F10.7 *** experiment shows that the BoxCox transformation significantly improves the predictive performance and our new approach works substantially better than the prediction from the US Airforce and other alternative methods like Auto-regressive Model,Multi-layer Perceptron,and Support Vector Regression.

关键词： Sun:radio radiation methods:data analysis methods:statistical