排序方式: 共有9条查询结果,搜索用时 15 毫秒
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不含金属的碳材料通过廉价且易获得的柚子皮经KOH活化和高温热解获得,该碳材料具有高比表面积(1 055 m~2·g~(-1))和高石墨化程度的类蜂窝状结构。将多孔碳(PAC)材料修饰后的电极作为工作电极,采用阳极溶出伏安法(SWASV)同步检测Cd~(2+)、Pb~(2+)和Cu~(2+)离子,表现出较高的灵敏度、可重复性、稳定性和较低的检测限。研究认为PAC的微孔和中孔可以充当有效的离子传递通道,从而加速离子的扩散并显著提高交换效率,而高的石墨化程度提高了材料的导电性,加速了电子传输。 相似文献
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REN Ji-Rong WANG Ji-Biao LI Ran XU Dong-Hui DUAN Yi-Shi 《理论物理通讯》2008,50(9):777-780
Two kinds of topological soliton (skyrmion and magnetic vortex ring) in ferromagnets are studied. They have the common topological origin, a tensor Hαβ = n→·(δαn→×βδn→), which describes the non-trivial distribution of local orientation of magnetization n→ at large distances in space. The topological stability of skyrmion is protected by the winding number. Knot-like topological defect as magnetic vortex rings is also studied. On the assumption that magnetic vortex rings are geometric lines, we present their δ-function distribution in ferromagnetic materials. Furthermore, it is briefly shown that Hopf invariant is a proper topological invariant to describe the topology of magnetic vortex rings. 相似文献
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Tan Zhi-Cheng Zhang Ji-Biao Shang-He Meng 《Journal of Thermal Analysis and Calorimetry》1999,55(1):283-289
A computerized adiabatic calorimeter for heat capacity measurements in the temperature range 80–400 K has been constructed.
The sample cell of the calorimeter, which is about 50 cm3 in internal volume, is equipped with a platinum resistance thermometer and surrounded by an adiabatic shield and a guard
shield. Two sets of 6-junction chromel-copel thermocouples are mounted between the cell and the shields to indicate the temperature
differences between them. The adiabatic conditions of the cell are automatically controlled by two sets of temperature controller.
The reliability of the calorimeter was verified through heat capacity measurements on the standard reference material α-Al2O3. The results agreed well with those of the National Bureau of Standards (NBS): within ±0.2% throughout the whole temperature
region. The heat capacities of high-purity graphite and polystyrene were precisely measured in the interval 260–370 K by using
the above-mentioned calorimeter. The results were tabulated and plotted and the thermal behavior of the two materials was
discussed in detail. Polynomial expressions for calculation of the heat capacities of the two substances are presented.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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WANG Ji-Biao REN Ji-Rong LI Ran 《理论物理通讯》2009,51(1):157-160
By making use of the C-mapping topological current theory and the decomposition of gauge potential theory, we investigate the (2+1)-dimensional skyrmion excitations in ferromagnets. We also discuss the branch processes of these skyrmions and the generation and annihilation of skyrmion-antiskyrmion pairs. 相似文献
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貉被毛的电镜观察和X射线能谱分析 总被引:15,自引:1,他引:14
本文对貉被毛的形态结构进行了扫描电镜观察,并且利用X射线能谱仪分别对鳞片层、皮质层和髓层进行了元素分析。结果表明:不同科属动的毛纤维其结构和元素成分存在差异。可为动物纤维的性能研究,鉴别及动物分类提供依据。 相似文献
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黄鼠狼尾毛和马身毛的X射线能谱微区分析鉴别方法研究 总被引:3,自引:0,他引:3
本文用电子显微镜和X射线能谱仪对黄鼠狼尾毛和马身手进行了元素微区分析,实验表明黄鼠狼尾毛和马身毛的鳞片层和髓质层所含微量元素有明显区别,这项研究为科学地鉴别两种毛纤维提供了科学依据。 相似文献
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家猫针毛的形态研究和X射线能谱元素分析 总被引:7,自引:1,他引:6
本文对家猫针毛的形态结构进行了扫描电镜(SEM)观察,并且利用X射线能谱仪(EDAX)分别为鳞片层、皮质层和髓质层进行了元素分析。结果表明:家猫针毛具有特殊的形态结构,针毛纤维各层间所含元素有明显区别。可为家猫针毛的性能研究及鉴别提供依据。 相似文献
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WANG Ji-Biao REN Ji-Rong LI Ran 《理论物理通讯》2009,51(2):335-340
Based on the φ-mapping topological current theory and the decomposition of gauge potential theory, the vortex lines and the monopoles in electrically conducting plasmas are studied. It is pointed out that these two topological structures respectively inhere in two-dimensional and three-dimensional topological currents, which can be derived from the same topological term n^→·(Эin^→×Эjn^→), and both these topological structures axe characterized by the φ-mapping topological numbers-Hopf indices and Brouwer degrees. Furthermore, the spatial bifurcation of vortex lines and the generation and annihilation of monopoles are also discussed. At last, we point out that the Hopf invaxiant is a proper topological invaxiant to describe the knotted solitons. 相似文献
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