BAL■ P
,
ACHIMOVI■OV M
,
SEPLAK VInstitute of Geotechnics of Slovak Academy of Sciences
,
Kosice
,
SlovakiaBASTLZJ.Heyrovsky Institute of Physical Chemistry
,
Academy of Sciences of the Czech Republic
,
Prague
,
C. R. LIPAKJSlovak Technical University
,
Electrotechnical Faculty
,
Bratislava
,
Slovakia Manuscript received 22 February
,
1994
金属学报(英文版)
The mechanical activation of tetrahedrite Cu_(12)Sb_(4)S_(13) was carried out in a planetary mill. The changes in the surface and bulk properties produced in mineral by mechanical activation were detected by infrared, photoelectron and Mossbauer spectroscopy. The rate and selectivity of tetrahedrite acid leaching depends on conditions of mechanical activation.
关键词:
mechanical activation
,
null
,
null
杨慧芬
,
唐琼瑶
,
王传龙
,
张露
,
李甜
中国有色金属学报
为考察红城红球菌(Rhodococcus erythropolis,R. erythropolis)作为赤铁矿捕收剂使用的可能性及效果,对R. erythropolis形貌、细胞壁成分及其吸附前后赤铁矿、石英表面电性、疏水性进行分析,对赤铁矿、石英单矿物以及赤铁矿与石英矿1:1(质量比)混合矿进行浮选实验,对其在赤铁矿表面的吸附状况及吸附机理进行研究.结果表明,杆状R. erythropolis表面既含有非极性基团,又含有极性基团,使得其表面具有较高的负电性和较强的疏水性,因而对赤铁矿的吸附作用明显大于对石英的吸附作用.当以此细菌为捕收剂、在溶液 pH 值为6、R. erythropolis用量为75 mg/L时,赤铁矿的回收率为89.68%,而石英的回收率仅为26.25%.混合矿经过一次浮选,可获得铁品位和回收率分别为50.08%和76.41%的铁精矿.R. erythropolis在赤铁矿表面发生复杂的化学吸附且使赤铁矿颗粒形成疏水絮团,从而证实R. erythropolis可作为赤铁矿的捕收剂使用.
关键词:
R. erythropolis
,
微生物
,
赤铁矿
,
石英
,
吸附
,
絮团
,
捕收剂
张颖
,
何茂刚
,
刘洋
工程热物理学报
改进了倾斜管式黏度测量实验系统,使其能够适用于非共沸物质饱和液相黏度的测量.对制冷剂 R22的替代物质一近共沸二元混合制冷剂R410A和非共沸三元混合制冷剂R407C的饱和液相运动黏度进行了测量,实验温度范围为256.15～336.15 K.同时,依据实验数据建立了制冷剂R410A和R407C饱和液相运动黏度与温度的关联式.
关键词:
运动黏度
,
R410A
,
R407C
,
实验测量
Journal of Applied Physics
The magnetic properties of R2Co14B1-xCx (x=0, 0.5 and R=Y, Sm) compounds have been studied by measuring the temperature dependence of the easy- and hard-magnetization curves on magnetically aligned samples between 1.5 and 300 K for Y2Co14(B,C) and at 4.2 K for Sm2Co14(B,C). The magnetic anisotropy of Y2Co14B increases due to the substitution of C for B, whereas the saturation magnetization decreases. Between 1.5 and 300 K, the anisotropy field of Y2Co14B0.5C0.5 increases about 2 T and the Co moment decreases about 0.05mu(B). The anisotropy field Of Sm2Co14B also increases upon C substitution and the saturation magnetization decreases slightly. The ac susceptibilities of both SM2Co14B and Sm2Co14B0.5C0.5 exhibit anomalies that may arise from a spin reorientation within the basal plane.
关键词:
nd2fe14b;exchange;nd2co14b;r2fe14b;field
Solid State Communications
Magnetic anisotropy fields at room temperature of ternary tetragonal compounds of R2Fe14C(R = Lu, Gd, Nd) and R2Fe14B(R = Gd, Nd) were determined by Singular-Point-Detection (SPD) technique. The magnetocrystalline anisotropies of the carbides were found to be larger than those of their corresponding borides, indicating that the outstanding permanent-magnetic properties may be obtained in the R2Fe14C-based alloys.
关键词:
李兴
,
俞坚
工程热物理学报
本文以三元非共沸混合工质R407C对传统工质HCFC22进行了替代,搭建了地源热泵系统实验台.考虑到在地源热泵运行时,地下土壤温度会因运行时间和冬夏季节的不同而发生变化,造成热泵的各种不同运行工况.为全面反映热泵的运行状态制订了测试方案,并对测试数据进行了整理和分析.该热泵系统在加热与制冷运行模式下COP均可达到3.6以上.
关键词:
地源热泵
,
混合工质R407C
,
运行工况
,
性能测试
Journal of Magnetism and Magnetic Materials
The temperature dependence of the anisotropy field H(A) and the thermal expansion DELTA-l/l0 of R2Fe14X (R = Gd, Lu; X = B,C) were measured by applying the SPD technique for H(A)(T) and a membrane technique for DELTA-l(T)/l0. Comparing Lu2Fe14B and Lu2Fe14C the difference in the temperature dependence of H(A) is associated with the difference in the Invar-like thermal expansion between the two compounds.
关键词:
3d magnetism;anisotropy;gd2fe14b
Journal of Applied Physics
In Ho2Fe14B and Ho2Fe14C the temperature dependence of the ac initial susceptibility between 4.2 and 300 K shows two peaks. The peak at the lower temperature can be explained by a well-known spin reorientation transition (at 62 K for Ho2Fe14B and at 40 K for Ho2Fe14C). The peak at the higher temperature (at 245 K for Ho2Fe14B and at 265 K for Ho2Fe14C) disappears when the external field is applied parallel or perpendicular to the preferential direction of a magnetically aligned sample. The similar peak was also traced for R2Fe14X compounds (R = Sm, Tb, Dy, Ho, Er, and Tm; X = B or C). Searching for the nature of this peak traced by measuring the temperature dependence of the ac susceptibility for 3d-4f compounds is still under progress.
关键词:
Journal of Solid State Chemistry
The subsolidus phase relations of R2O3-CaO-CuO ternary systems (R = Nd, Sm, Gd, Tm) have been investigated by X-ray powder diffraction. All samples were synthesized at about 950degrees in air. There exists a ternary compound Ca14-xRxCu24O41 (x = 4 for R = Nd, Gd and x = 5 for R = Sm) and a ternary solid solution Ca2+xR2-xCu5O10 (R = Nd, Sm, Gd, Tm) with a wide composition range Deltax of about 0.6. The compound Ca14-xRxCu24O41 possesses a layered orthorhombic structure and is isostructural to Sr14-xCaxCu24O41. The lattice parameters a and c of the compound are basically independent of the ionic radius of R, while the lattice parameter b and unit-cell volume V decrease substantially with the decrease of the ionic radii of R. The Ca2+xR2-xCu5O10 solid solution is isostructural to Ca2+xY2-xCu5O10, the structure of which is based on an orthorhombic "NaCuO2-type" subcell containing infinite one-dimensional chains of edge-shared square planar cuprate groups crosslinked by the layered cations Ca and R that locate in the inter-chain tunnels. (C) 2002 Elsevier Science (USA). All rights reserved.
关键词:
R2O3-CaO-CuO (R = Nd, Sm, Gd, Tm) systems;phase relations;Ca10R4Cu24O41 (R = Nd, Sm, Gd) structure;Ca2+xR2-xCu5O10 (R = Nd, Sm,;Gd, Tm) structure;ternary-system;approximately 950-degrees-c;high-pressure;superconductivity;diagram;air;er;compatibilities;property;oxide
