High Gd Concentration GaGdN Grown at Low Temperatures

GaGdN layers were grown at temperatures below 300°C by radio-frequency plasma-assisted molecular beam epitaxy on sapphire substrates. GaGdN samples with high Gd concentration as high as 12.5% were obtained by lowering the growth temperature. X-ray diffraction results showed no obvious secondary phase, which means that the phase separation can be suppressed by the growth at low temperatures. All samples, including those grown at room temperature, showed ferromagnetic characteristics. Photoluminescence emission was observed, though spectra exhibit broad and sharp luminescence bands related to many kinds of defects. It is suggested that electrons coming from defects, especially, nitrogen vacancy, stabilize ferromagnetism, and that the carrier-induced ferromagnetism occurs in the low-temperature-growth GaGdN.     

Industrialization of High Performance Sintered NdFeB Magnets

Sintered Nd-Fe-B magnet was manufactured by advanced equipment via a SC (Strip casting) technology.It has integrative performance.     

Crystalline Behavior and Magnetic Properties of Nd60Fe30-x Al10Cox（x = 0,5,10） Bulk Amorphous Alloys

Crystalline behavior and magnetic properties of Nd60Fe30-xAl10Cox( x = 0, 5, 10) bulk amorphous alloys were investigated by differential scanning calorimeter (DSC), X-ray diffraction (XRD) and the vibrating sample magnetometer (VSM). Neither glass transition nor supercooled liquid region before crystallization was observed for the as-cast Nd60Fe30-xAl10Cox ( x = 0,5,10) bulk amorphous alloys. The glass forming ability can be improved significantly by the addition of Co. The as-cast Nd60Fe30-xAl10Cox (x = 0,5,10) alloys show hard magnetic behavior. With the addition of Co content, intrinsic coercivity (iHc) increases while the saturation magnetization(σs) and remanence (σr) decrease. The Curie temperature for the as-cast Nd60Fe30-xAl10Cox alloys increases from 451 K for x =0 to 468 K for x = 10. Some pre-cipitation of crystalline phases does not affect the hard magnetic properties of Nd60Fe30-xAl10Cox(x = 0,5,10) alloys, while the hard magnetic behavior disappears quickly after the alloys being completely crystallized.     

苏北及邻区前志留基础层的综合地球物理研究

在前新生代油气资源选区评价中，前志留面之下未变质沉积地层（简称前志留基础层）的分布具有重要的参考价值。从提高纵向分辨率的处理和反演技术的应用入手，结合约束条件,利用大地电磁测深数据反演,揭示前志留面等界面的埋深和分布；同时应用小波分析技术，从磁场中分解出区域磁异常，反演结晶基底的埋深。通过这2个界面埋深的差异来分析前志留基础层的分布     

Properties of Quaternary Alloy Magnetic Semiconductor (InGaMn)As Grown on InP

We have studied properties of quaternary alloy magnetic semiconductor (InGaMn)As grown on InP substrates by low-temperature molecular-beam epitaxy (LT-MBE). A large MCD peak whose intensity is larger than 500 mdeg for (InGaMn)As was observed. This peak intensity was about three times larger than that of typical (GaMn)As films. Relatively high Curie temperature of 83 K of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was observed by Hall measurements. The carrier concentration of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was estimated to be more than 1.0 × 10²¹ cm^–3 by using the Curie–Weiss fitting of the Hall coefficient R _H, indicating that more than 40% of Mn atoms are activated. This means that (InGaMn)As has a higher activation ratio of Mn as acceptors than (GaMn)As.     

尖晶石型软磁铁氧体纳米材料的制备研究进展

介绍了软磁铁氧体纳米材料的特性,综述了近年来具有尖晶石结构的软磁铁氧体纳米材料的制备方法。其中包括:化学共沉淀法,水热法,溶胶-凝胶法,喷雾热解法,微乳液法,相转化法,超临界法,冲击波合成法,微波场下湿法合成,爆炸法,高能球磨法,自蔓延高温合成法等。详细介绍了各种制备方法的特点,研究进展及其发展趋势。     

Preparation of micrometer‐sized,monodisperse, magnetic polymer particles

Micrometer‐sized, monodisperse, magnetic composite particles were prepared by heating micrometer‐sized, monodisperse, hollow polystyrene/polydivinylbenzene composite polymer particles at 200°C for 4 h (particles had been dipped in pentacarbonyliron) and then washed in 12 N HCl and water. The hollow polymer particles were produced by seeded polymerization by the dynamic swelling method that was proposed by authors. The magnetic composite particles contained Fe₃O₄, the content of which was 49% based on total weight, and were attracted easily in water by a 1650 G magnet. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 428–433, 2003     

某难选铅锌矿石浮选分离新工艺试验研究

针对某难选铅锌矿的矿石性质，进行了较为系统的小型试验研究。结果表明：在铅循环中采用Bx SN—9^#组合捕收剂、石灰 ZL—01组合抑制剂，在锌循环中采用捕收剂磁处理浮选技术等措施，可以较好地解决该难选矿的浮选分离问题。     

导磁不锈钢毛的结构化研究

研制了一种新型的结构化钢毛——胶结钢毛。和传统的普通钢毛相比,胶结钢毛具有很强的结构刚度和很低的钢毛流失量;同时,对高岭土有较高的除铁效率。     

电磁铸造液柱高度数学模型的建立及应用

为了研究熔体金属电磁立柱成形能力并计算电磁作用下的液注高度,从电磁铸造立柱成形的基本原理出发,建立了电磁场作用下金属立柱成形时液柱高度数学模型,并试验验证了模型的准确性.利用液柱高度数学模型对铝、钢、锡铅合金等金属的电磁铸造可行性,以及电力参数对液柱高度的影响进行研究.结果表明:铝电磁无模成形能力最强,而钢及锡铅合金电磁无模成形能力则基本相同;钢及锡铅合金电磁立柱成形所需的磁感强度约为0.08～0.10 T,而铝则只需约0.04T.