Temperature Dependence of the Magnetocrystalline Anisotropy in Nd_2Co_(14)B Compound

Easy and hard magnetization curves of Nd_2Co_(14)B compound have been measured withextracting-sample-magnetometer(μ_0H_(max)=6T)at 10～300 K.Magnetic anisotropy constants K_1 and K_2have been determined by fitting the hard magnetization curves,in which only K_1 ,K_2 and misalignment anglehave been taken as fitting parameters.The values of K_1 and K_2 at 4.2 K were derived by extrapolation.Anisotropy coefficients,x_2~° and x_4~°were derived from the anisotropy constants.The anisotropy constant K_2increases rapidly with increasing temperature when TT_(sr).The temperature depen-dence of the magnetic anisotropy coefficient x_2~° was fitted with the formula.The anisotropy coefficients x_2~°can be well described by the tenth-power law from 4.2 K to T_(sr)and by the sixth-power law from T_(sr_ to 300 K.     

煤巷机掘单孔月进1153.3米

我矿601煤巷快速掘进队,于今年3月,使用AM-50型煤巷掘进机,在断面14米~2、使用新型金属拱形可缩性支架的2172北运输道,创出煤巷单孔月进1153.3米的优异成绩。 1.工程概况 2172北工作面是综采队年产原煤百万吨工作面之一,6月份接替2174I作面的综采生产。该面位于第二水平北翼一采区上区段,走向长度830米,倾斜长度130米,煤层厚度4.2～4.7米,倾角11°～13°,单一稳定厚煤层,可采煤量54万吨。煤层顶板是一层厚1米的粉砂岩,岩性破碎,层理发育。再上是