Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material最新文献_第3页

Effect of Cu doping and annealing treatment on the microstructure and magnetic properties of nanocrystalline single-phase Nd-Fe-B alloys Cu掺杂和退火处理对纳米晶单相Nd-Fe-B合金组织和磁性能的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60282-0

Xiaoqian Bao, Xuexu Gao, Maocai Zhang, Yi Qiao, Xiaoyan Guo, Jie Zhu, Shouzeng Zhou

{"title":"Effect of Cu doping and annealing treatment on the microstructure and magnetic properties of nanocrystalline single-phase Nd-Fe-B alloys","authors":"Xiaoqian Bao, Xuexu Gao, Maocai Zhang, Yi Qiao, Xiaoyan Guo, Jie Zhu, Shouzeng Zhou","doi":"10.1016/S1005-8850(08)60282-0","DOIUrl":"10.1016/S1005-8850(08)60282-0","url":null,"abstract":"<div>The effects of Cu addition and annealing treatment on the magnetic properties and microstructure of Nd12.3Fe81.7–xCuxB6 (x=0–1.2) ribbons melt-spun and annealed were systematically investigated by the methods of vibrating sample magnetometer (VSM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Optimum magnetic properties were achieved by annealing melt-spun Nd12.3Fe81.5Cu0.2B6 ribbons at 550°C for 15 min, which only contained Nd2Fe14B phase. The remanence, coercive force, and maximum energy product increase by 18.4%, 36.2%, and 49% respectively compared with those of Cu-free samples. The significant improvement in magnetic properties originates from the finer grains of the samples by introducing Cu, which leads to the stronger exchange-coupling between neighboring grains.</div>","PeriodicalId":100851,"journal":{"name":"Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material","volume":"15 6","pages":"Pages 753-757"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-8850(08)60282-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86521066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New development of hydraulic fracturing technique for in-situ stress measurement at great depth of mines 大深部地应力测量水力压裂技术的新进展

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60268-6

Meifeng Cai , Hua Peng , Hongguang Ji

引用次数: 18

Effects of different iron sources on the performance of LiFePO4/C composite cathode materials 不同铁源对LiFePO4/C复合正极材料性能的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60291-1

Fei Gao , Zhiyuan Tang , Jianjun Xue

{"title":"Effects of different iron sources on the performance of LiFePO4/C composite cathode materials","authors":"Fei Gao , Zhiyuan Tang , Jianjun Xue","doi":"10.1016/S1005-8850(08)60291-1","DOIUrl":"10.1016/S1005-8850(08)60291-1","url":null,"abstract":"<div>Olivine LiFePO4/C composite cathode materials were synthesized by a solid state method in N2 + 5vol% H2 atmosphere. The effects of different iron sources, including Fe(OH)3 and FeC2O4·2H2O, on the performance of as-synthesized cathode materials were investigated and the causes were also analyzed. The crystal structure, the morphology, and the electrochemical performance of the prepared samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), laser particle-size distribution measurement, and other electrochemical techniques. The results demonstrate that the LiFePO4/C materials obtained from Fe(OH)3 at 800°C and FeC2O4·2H2O at 700°C have the similar electrochemical performances. The initial discharge capacities of LiFePO4/C synthesized from Fe(OH)3 and FeC2O4·2H2O are 134.5 mAh·g−1 and 137.4 mAh·g−1 at the C/5 rate, respectively. However, the tap density of the LiFePO4/C materials obtained from Fe(OH)3 are higher, which is significant for the improvement of the capacity of the battery.</div>","PeriodicalId":100851,"journal":{"name":"Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material","volume":"15 6","pages":"Pages 802-807"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-8850(08)60291-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77641268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Thermal conductivity measurements on xonotlite-type calcium silicate by the transient hot-strip method 瞬态热带法测定硅钙石型硅酸钙的导热系数

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60289-3

Gaosheng Wei , Xinxin Zhang , Fan Yu

{"title":"Thermal conductivity measurements on xonotlite-type calcium silicate by the transient hot-strip method","authors":"Gaosheng Wei , Xinxin Zhang , Fan Yu","doi":"10.1016/S1005-8850(08)60289-3","DOIUrl":"10.1016/S1005-8850(08)60289-3","url":null,"abstract":"<div>The experimental results of the thermal conductivities of xonotlite-type calcium silicate insulation materials were presented at different temperatures and pressures. Two appropriative surroundings, i.e. an elevated temperature surrounding from ambient temperature to 1450 K and a vacuum surrounding from atmosphere pressure to 10−3 Pa, were designed for the transient hot-strip (THS) method. The thermal conductivities of xonotlite-type calcium silicate with four densities from ambient temperature to 1000 K and 0.045 Pa to atmospheric pressure were measured. The results show that the thermal conductivity of xonotlite-type calcium silicate decreases apparently with the fall of density, and decreases apparently with the drop of pressure, and reaches the least value at about 100 Pa. The thermal conductivity of xonotlite-type calcium silicate increases almost linearly with T3, and increases more abundantly with low density than with high density. The thermal conductivity measurement uncertainty is estimated to be approximately 3% at ambient temperature, and 6% at 800 K.</div>","PeriodicalId":100851,"journal":{"name":"Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material","volume":"15 6","pages":"Pages 791-795"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-8850(08)60289-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91459020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Effect of different additives on the properties of lithium alanate 不同添加剂对丙酸锂性能的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60288-1

Xueping Zheng , Ping Li , Xuanhui Qu , I.S. Humail , Yanghuan Zhang , Guoqing Wang

引用次数: 2

Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment 酸性土壤环境中组织劣化对X70管线钢应力腐蚀开裂的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60275-3

Zhiyong Liu, Guoli Zhai, Xiaogang Li, Cuiwei Du

{"title":"Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment","authors":"Zhiyong Liu, Guoli Zhai, Xiaogang Li, Cuiwei Du","doi":"10.1016/S1005-8850(08)60275-3","DOIUrl":"10.1016/S1005-8850(08)60275-3","url":null,"abstract":"<div>In order to investigate stress corrosion cracking (SCC) of X70 pipeline steel and its weld joint area in acidic soil environment in China, two simulating methods were used: one was to obtain bad microstructures in heat affected zone by annealing at 1300°C for 10 min and then, quenching in water; the other was to get different simulating solutions of acidic soil in Yingtan in southeast China. The SCC susceptibilities of X70 pipeline steel before and after quenching in the simulating solutions were analyzed using slow stain rate test (SSRT) and potentiodynamic polarization technique to investigate the SCC electrochemical mechanism of different microstructures further. The results show that SCC appears in the original microstructure and the quenched microstructure as the polarization potential decreases. Hydrogen revolution accelerates SCC of the two tested materials within the range of −850 mV to −1200 mV vs. SCE. Microstructural hardening and grain coarsening also increase SCC. The SCC mechanisms are different, anodic dissolution is the key of causing SCC as the polarization potential is higher than the null current potential, and hydrogen embrittlement will play a more important role to SCC as the polarization potential lower than the null current potential.</div>","PeriodicalId":100851,"journal":{"name":"Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material","volume":"15 6","pages":"Pages 707-713"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-8850(08)60275-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83509512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

SiC/Si-W-Mo coating for protection of C/C composites at 1873 K SiC/Si-W-Mo涂层在1873 K下保护C/C复合材料

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60294-7

Dangshe Hou, Kezhi Li, Hejun Li, Qiangang Fu, Yulei Zhang

引用次数: 2

Effect of zirconium addition on the austenite grain coarsening behavior and mechanical properties of 900 MPa low carbon bainite steel 添加锆对900 MPa低碳贝氏体钢奥氏体晶粒粗化行为及力学性能的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-12-01 DOI: 10.1016/S1005-8850(08)60272-8

Jia Guo , Aimin Guo , Hui Guo , Ying Wang , Jing Li , Xinlai He

引用次数: 2

Application of Al-free deoxidizer in rail steel manufacture 无铝脱氧剂在轨道钢生产中的应用

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-10-01 DOI: 10.1016/S1005-8850(08)60100-0

Wei Wu, Liu Liu

引用次数: 2

Prediction of operational parameters effect on coal flotation using artificial neural network 应用人工神经网络预测浮选工艺参数对浮选效果的影响

Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material Pub Date : 2008-10-01 DOI: 10.1016/S1005-8850(08)60099-7

E. Jorjani, Sh. Mesroghli, S. C. Chelgani

引用次数: 32