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| 1 | Tailoring the mechanical anisotropy of sintered NdFeB magnets by Pr-Cu grain boundary reconstruction显示文摘Pr_(83)Cu_(17)(wt%) grain boundary reconstruction was applied to prepare sintered NdFeB magnets. The effects of addition amount and annealing on the bending strength were investigated. The results show that Pr_(83)Cu_(17) can not only effectively enhance the bending strength, but also change the mechanical anisotropy in two directions parallel and perpendicular to c-axis. The bending strength perpendicular to c-axis reaches 404 MPa in 10 wt% addition magnet, higher than 348 MPa along parallel direction. This change is attributed to the preferred distribution of boundary phases, i.e., ductile(Nd,Pr)-Fe-Cu phase along perpendicular direction to c-axis and(Nd,Pr)-Fe phase along parallel direction. Moreover, the Cu migration during 480 ℃ annealing is found to be related to this boundary phase distribution. | Minghui Tang Xiaoqian Bao Xuejiao Zhang Xing Mu Kechao Lu Jiheng Li Xuexu Gao | 2019 | Journal of Rare Earths2019，37，4： | 7 |
| 2 | Effect of Ga addition on the magnetic properties and microstructure of nanocrystalline Nd_(12.3)Fe_(81.7)B_(6.0) ribbons显示文摘Nd 12.3 Fe 81.7 x Ga x B 6.0 (x = 0-1.8) ribbons were prepared by melt spinning at 22 m/s and subsequent annealing treatment. The influences of Ga addition and annealing conditions on the magnetic properties and microstructure of the nanocrystalline alloys were systematically investigated. After being annealed at 620℃ for 20 min, the J r and H ci increased from 0.85 T and 582.6 kA/m for Ga-free sample to 0.97 T and 734.6 kA/m for the x = 0.9 sample, respectively. The (BH) max for the x = 0.9 sample increased by about 40% from 96.3 to 135.5 kJ/m 3 compared with that of the Ga-free one. The significant improvement of magnetic properties originated from the refinement of grains in the samples by introducing Ga, which led to a stronger exchange coupling between the neighboring grains in comparison with that in Ga-free samples. The microstructure and magnetic properties of the samples depended strongly on annealing parameters, while the sensitivity of micro-structure to annealing conditions could be significantly suppressed by the addition of Ga element. | BAO Xiaoqian GUO Xiaoyan GUO Jianchun GAO Xuexu | 2011 | Rare Metals2011，30，5： | 3 |
| 3 | Effect of annealing time on the exchange coupling interactions and microstruc-ture of nanocomposite Pr_(7.5)Dy_1Fe_(71)Co_(15)Nb_1B_(4.5) ribbons显示文摘The influence of annealing time on the magnetic properties and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons was systematically investigated by the methods of vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Interaction domains derived from strong exchange coupling interactions be- tween hard and soft magnetic grains were imaged using magnetic force microscopy (MFM). Maximum remanence, intrinsic coerciv- ity, and maximum energy product values were obtained in the ribbons annealed at 700°C for 15 min, which were composed of Pr2(Fe, Co)14B, α-(Fe, Co), and slight Pr2(Fe, Co)17 phases. Although Jr, Hci, and (BH)max decreased gradually with further increase of an- nealing time, it is emphasized that comparatively high Jr and Hci and (BH)max were obtained in a wide annealing time period of 15 to 360 min. The shape of initial magnetization curves and hysteresis loops change as a function of annealing time, indicating different magnetization reversal routes, which can be fully explained by the corresponding microstructure. | Xiaoqian Bao Yi Qiao Xuexu Gao Maocai Zhang Jie Zhu Shouzeng Zhou | 2007 | Journal of University of Science and Technology Beijing2007，14，6： | 3 |
| 4 | Giant Magnetostrictions of Tb-Dy-Fe Polycrystals with < 110 > Axial Alignment显示文摘Preparing method and processing of Tb-Dy-Fe alloy samples with [110] axial orientation as well as their magnetostrictive properties have been studied. It has been found that the magnetostrictive strains of polycrystal samples with [110] axial orientation can reach (1550-1900) ×10^-6 in a low magnetic field less than 80 kA/m, which are equal to or somewhat better than that of the polycrystal samples with [112] axial orientation. | Shouzeng ZHOU, Xuexu GAO, Maocai ZHANG, Qing ZHAO and Zhenhlla SHI (State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China) | 2000 | Journal of Materials Science & Technology2000，16，2： | 2 |
| 5 | Microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR) treated Nd-Fe-B strip cast alloys显示文摘In this paper,we systematically investigated the microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR)treated Nd-Fe-B strip cast alloys by transmission electron microscopy(TEM)and three-dimensional atom probe(3 DAP)analyses.The rodlike NdH_(2+x) phases with diameters of 10-20 nm are embedded intoα-Fe matrix,which hereditarily leads to textured grains in HDDR alloy.The migration of NdH_(2+x) from Nd-rich region toα-Fe matrix during hydrogen absorption process contributes to the uniform redistribution of Nd-rich phases after HDDR treatment The HDDR alloy with single domain grain sizes of 200-300 nm exhibits relatively low coercivity of 1.01 T that arises from pinning magnetic domain motion.The weak c-axis orientation of HDDR alloy results in a lower reverse magnetic field(coercivity)to reduce remanence to 0.Moreover,the direct contact of Nd_(2)Fe_(14)B grains and the high concentration of ferromagnetic elements(Fe content≈66.06 at%,Co content≈0.91 at%)in Nd-rich grain boundary layer lead to strong magnetostatic coupling effect among Nd_(2) Fe_(14)B grains.The nano-sized a-Fe inside Nd_(2) Fe_(14)B matrix makes the magnetization reversal easily and decreases the coercivity of HDDR alloy. | Bin Ma Xiaoqian Bao Aizhi Sun Jiheng Li Xuexu Gao | 2022 | Journal of Rare Earths2022，40，5： | 2 |
| 6 | Texture evolution and mag- netostriction in rolled (FEB1 Ga19)99 Nbl alloy显示文摘 | Li Jiheng Gao Xuexu Zhu Jie | 2009 | J Alloys Compd2009，476，12： | 1 |
| 7 | 显示文摘 | Zhou Shouzeng Gao Xuexu Zhang Maocai | 2000 | J Mater Sel Teehnol2000，16，2： | 1 |
| 8 | Two-layer simulation model of laser-induced interstitial thermo- therapy 显示文摘 | MA Ning GAO Xiang ZHANG Xuexue | 2004 | Lasers in Med Sci2004，18，： | 1 |
| 9 | Effect of additive elements on exchange coupling and spin reorientation transition of nanocrystalline single-phase Nd-Fe-B alloy显示文摘Nd12.3Fe81.7-xZrxB6.0 (x=0,1.5) and (NdDyTb)12.3(FeZrNbCu)81.7-yCoyB6.0 (y=0,12) ribbons were prepared by melt spinning at 22 m/s and subsequent annealing.The influences of Zr,Dy/Tb and Co substitutions on magnetic properties and spin reorientation transitions of nanophase Nd2Fe14B have been systematically investigated.Compared with Zr-free sample,the remanence,intrinsic coercivity and maximum energy product for Nd12.3Fe80.2Zr1.5B6.0 ribbon increase by 10.8 %,17.8 % and 60.2 %,respectively.The significant improvement of magnetic properties originates from the finer grains of the sample by introducing Zr,which leads to the stronger exchange coupling between neighboring grains.The intrinsic coercivity for (DyTb)-substituted ribbon is significantly increased although the remanence is reduced,which could be compensated by the substitution of Co for Fe.The spin reorientation temperature Tsr of nanocrystalline Nd2Fe14B alloys was determined by measuring the ac magnetic susceptibility.It was found to be lower than that of bulk Nd2Fe14B.The substitutions of Zr,Dy/Tb and Co result in reduction of Tsr.The smaller the grain size,the lower the Tsr will be.Influence of spin reorientation on magnetization characteristics of nanophase Nd2Fe14B was discussed. | BAO XiaoQian,GAO XueXu,ZHU Jie & ZHOU ShouZeng State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China | 2010 | Science China(Technological Sciences)2010，53，9： | 1 |
| 10 | Effect of quenching on magnetostriction and microstructure of melt-spun Fe83Ga]7 alloy 显示文摘 | Sun Li Zhang Maocai Gao Xuexu | 2008 | J Alloys Compd2008，463，： | 1 |
| 11 | Microstructure refinement and magnetic properties enhancement of nanocrystalline Nd_(12.3)Fe_(81.7)B_(6.0) ribbons by addition of Zr显示文摘Effects of Zr addition and annealing treatment on the formation, microstructure and magnetic properties of Nd12.3Fe81.7?xZrxB6.0 (x=0―3.0) ribbons melt-spun and annealed have been systematically investigated by means of vibrating sample magnetometer (VSM), differential scanning calorimeter (DSC), X-ray diffraction (XRD), and high resolution scanning electron microscopy (HRSEM). Phase analysis reveals that Nd2Fe14B is single-phase material. It has been found that the intrinsic coercivity Hci of the optimally processed Nd12.3Fe81.7?xZrxB6.0 ribbons increases monotonically from 751.7 kA/m for x=0 to 1005.3 kA/m for x=3.0. The remanence polarization Jr and maximum energy product (BH)max increase first with Zr addition, then slightly decrease with further increasing Zr content. Optimum magnetic properties with Jr=1.041 T, Hci=887.5 kA/m and (BH)max=175.2 kJ/m3 have been achieved for the ribbons with x=1.5. The significant improvement of magnetic properties originates from the finer grains of the ribbons by introducing Zr. | BAO XiaoQian, QIAO Yi, GAO XueXu, ZHU Jie & ZHOU ShouZeng State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China | 2009 | Science China(Technological Sciences)2009，52，7： | 0 |
| 12 | Enabling tandem oxidation of benzene to benzenediol over integrated neighboring V-Cu oxides in mesoporous silica显示文摘The direct tandem oxidation synthesis of benzenediol from benzene could simplify or even avoid the separation and purification of reaction intermediates, which is promising but challenged because of the further required immediate consecutive activation of intermediate phenol. In this work, a synergistic benzene tandem-oxidation catalyst that V-Cu bimetallic oxides modified nanoporous silica(VCu-NS)was constructed via a facile assembly strategy which involves addictive negative anion citric acid mediating the intercalation of metal-citric acid chelate in mesopore of silica and subsequent thermal calcination inducing dual-metal active site formation. Such a tactic could make amorphous VOxspecies well covered on the surface of mesopore, and ultrafine copper oxide particles surrounded and neighbored by highly dispersed VOxwith strong interplay in mesopore, which was comprehensively confirmed by various characterizations. Benefiting from the unique V-Cu neighboring effect, the desorption of formed phenol over the catalytic site might be restricted therefore easily further activated by the formed reactive oxidative species, 3VCu-NS shows synergetic tandem-oxidation catalytic activities for benzene towards benzenediol with a selectivity of 57%. The result allows optimal 3VCu-NS to be a promising catalyst for benzenediol synthesis from benzene. | Mengting Liu Xuexue Dong Zengjing Guo Aihua Yuan Shuying Gao Fu Yang | 2023 | Chinese Journal of Chemical Engineering2023，55，3： | 0 |
| 13 | Sparse representation scheme with enhanced medium pixel intensity for face recognition显示文摘Sparse representation is an effective data classification algorithm that depends on the known training samples to categorise the test sample.It has been widely used in various image classification tasks.Sparseness in sparse representation means that only a few of instances selected from all training samples can effectively convey the essential class-specific information of the test sample,which is very important for classification.For deformable images such as human faces,pixels at the same location of different images of the same subject usually have different intensities.Therefore,extracting features and correctly classifying such deformable objects is very hard.Moreover,the lighting,attitude and occlusion cause more difficulty.Considering the problems and challenges listed above,a novel image representation and classification algorithm is proposed.First,the authors’algorithm generates virtual samples by a non-linear variation method.This method can effectively extract the low-frequency information of space-domain features of the original image,which is very useful for representing deformable objects.The combination of the original and virtual samples is more beneficial to improve the clas-sification performance and robustness of the algorithm.Thereby,the authors’algorithm calculates the expression coefficients of the original and virtual samples separately using the sparse representation principle and obtains the final score by a designed efficient score fusion scheme.The weighting coefficients in the score fusion scheme are set entirely automatically.Finally,the algorithm classifies the samples based on the final scores.The experimental results show that our method performs better classification than conventional sparse representation algorithms. | Xuexue Zhang Yongjun Zhang Zewei Wang Wei Long Weihao Gao Bob Zhang | 2024 | CAAI Transactions on Intelligence Technology2024，9，1： | 0 |
| 14 | Effect of microstructure and defects on the magnetostriction of<110> oriented TDT-110 alloys显示文摘<110>oriented rods of TbDyFe giant magnetostrictive alloys have been prepared with the help of the zone melting direc- tional solidification technique with a high temperature gradient.To acquire optimal magnetostrictive properties at low magnetic field, the TbDyFe alloys have been heat-treated at different temperatures and cooled at different rates.The relationships between the proc- ess of the heat treatment,microstructure,defects,and magnetostrictive properties of the TbDyFe materials have been studied. | Haijun Tang Xuexu Gao Wei Wu Maocai Zhang Shouzeng Zhou | 2008 | Journal of University of Science and Technology Beijing2008，15，1： | 0 |
| 15 | Effect of Cu doping and annealing treatment on the microstructure and mag-netic properties of nanocrystalline single-phase Nd-Fe-B alloys显示文摘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 sig-nificant 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. | Xiaoqian Bao Xuexu Gao Maocai Zhang Yi Qiao Xiaoyan Guo Jie Zhu Shouzeng Zhou | 2008 | Journal of University of Science and Technology Beijing2008，15，6： | 0 |
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