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不定度规空间的可测场 总被引:2,自引:2,他引:2
杨海涛 《南昌大学学报(理科版)》1995,19(4):346-352
讨论了不定度规空间上的约化理论,引入了不定度规空间的可测场及其谐性的概念。给出了不定度规空间场是谐调可测场的充要条件以及谐调可测场的若干性质。 相似文献
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Determination of the magnetic anisotropy constant of Cu/Fe/SiO2/Si by a magneto-optical Kerr effect susceptometer 下载免费PDF全文
The magneto-optical Kerr effect susceptometry technique is proposed to determine the uniaxial magnetic anisotropy(UMA) constant Ku. The magnetic properties of Cu/Fe/SiO2/Si grown by dc magnetron sputtering were investigated. The in-plane uniaxial magnetic anisotropy was probed by the magneto-optical Kerr effect(MOKE). The value of UMA, Ku= 2.5×103J/m3, was simulated from the field dependence of ac susceptibility along the hard axis according to the Stoner–Wohlfarth(S–W) model, which is consistent with Ku= 2.7×103J/m3 calculated from the magnetic hysteresis loops. Our results show that the magneto-optical Kerr effect susceptometry can be employed to determine the magnetic anisotropy constant owing to its high sensitivity. 相似文献
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V-based kagome materials AV3Sb5 (A=K, Rb, Cs) have attracted much attention due to their novel properties such as unconventional superconductivity, giant anomalous Hall effect, charge density wave (CDW) and pair density wave. Except for the 2a0×2a0 CDW (charge density wave with in-plane 2×2 superlattice modulation) in AV3Sb5, an additional 1×4 (4a0) unidirectional stripe order has been observed at the Sb surface of RbV3Sb5 and CsV3Sb5. However, the stability and electronic nature of the 4a0 stripe order remain controversial and unclear. Here, by using low-temperature scanning tunneling microscopy/spectroscopy (STM/S), we systematically study the 4a0 stripe order on the Sb-terminated surface of CsV3Sb5. We find that the 4a0 stripe order is visible in a large energy range. The STM images with positive and negative bias show contrast inversion, which is the hallmark for the Peierls-type CDW. In addition, below the critical temperature about 60 K, the 4a0 stripe order keeps unaffected against the topmost Cs atoms, point defects, step edges and magnetic field up to 8 T. Our results provide experimental evidences on the existence of unidirectional CDW in CsV3Sb5. 相似文献
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以α-D-葡萄糖为起始物,用TEMPO/NaBr/NaClO体系催化氧化法合成α-D-葡萄糖醛酸。合成过程为:首先对α-D-葡萄糖上的C1位进行甲基化保护,然后用TEMPO/NaBr/NaClO体系对伯醇羟基进行催化氧化转化为羧基,最后脱甲基。对第三步稀盐酸水解法脱甲基的条件作了优化,分别水解15h、30h、45h、58h、65h,高效液相色谱(HPLC)结果显示,在水解58h时甲基葡萄糖醛酸钠基本水解完毕,葡萄糖醛酸水解得率最高,水解得率为64.9%。经过高效液相色谱提纯后的葡萄糖醛酸熔点为164.3~165.2℃(m.p.165℃),得率(基于α-D-葡萄糖)为45.2%。 相似文献
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Ⅱ1空间上JC*-代数的不变子空间 总被引:1,自引:0,他引:1
讨论了Ⅱ1空间上一般JC*-代数的不变子空间的存在条件问题,得到各类JC*-代数存在Ⅱ2型不变子空间的等价条件. 相似文献
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Monodispersive ZnO nanoparticles each with a hexagonal wurtzite structure are facilely prepared by the hightemperature organic phase method.The UV-visible absorption peak of ZnO nanoparticles presents an obvious blue-shift from 385 nm of bulk ZnO to 369 nm.Both the real part and the image part of the complex permittivity of ZnO nanoparticles from 0.1 GHz to 10 GHz linearly decrease without obvious resonance peak appearing.The real parts of intrinsic permittivity of ZnO nanoparticles are about 5.7 and 5.0 at 0.1 GHz and 10 GHz respectively,and show an obvious size-dependent behavior.The dielectric loss angle tangent(tan 5) of ZnO nanoparticles with a different weight ratio shows a different decreasing law with the increase of frequency. 相似文献
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