Positive exchange bias in a Ni80Fe20/NixFe1−xO thin-film bilayer

We have measured positive exchange bias in a Ni₈₀Fe₂₀/Ni_xFe_1−xO thin-film nanocrystallite system. A series of solid solution Ni_xFe_1−xO 40 nm thick films capped with 25 nm thick Ni₈₀Fe₂₀ were deposited using a range of %O₂/Ar bombardment energies (i.e. End-Hall voltages). Proper tuning of the deposition conditions results in a Ni₈₀Fe₂₀/Ni_xFe_1−xO (30%O₂/Ar) based bilayer that exhibits a positive exchange bias loop shift of H_ex∼60 Oe at 150 K.     

Comparison of coherent induced hole-burning between Λ, V and ladder systems

In this Letter, we investigate the novel coherent hole-burning phenomena in three different three-level Doppler broadening atomic Rb⁸⁷ systems. In the Λ model, coherent burning holes depend on Rabi frequency and detuning of the saturating laser as well as the nonradiative decay rate between ground levels. Comparing with V and Ladder models, we find that coherent burning holes in the Λ model are the most obvious.     

Variation of molecular stacking with different length of alkyl chain: synthesis, structure determination, and mesogenic study of N,N-disubstituted aminophenylazo-(4)-p-alkylbenzenes

To help understand the influence of polarity and length of the terminal alkyl chain of a molecule on the molecular stacking of a liquid crystal and on its mesogenic behaviour, four new aminophenylazo-(4)-p-alkylbenzenes were prepared and one of them was further studied by single crystal structure determination. The molecular stacking based on this crystallographic data was established, and compared with that of two previously reported homologues. The mesogenic behaviour of this series of compounds was also investigated.     

Using fuzzy integral for evaluating subjectively perceived travel costs in a traffic assignment model

A good traffic assignment model can be a powerful tool to describe the characteristics of traffic behavior in a road network. The traffic assignment results often play an important role in transportation planning, e.g., an optimal and economical network design. Many traditional traffic assignment models rely heavily on the travel cost function established by Wardrop’s principles; however, the Wardrop’s travel cost function has been proven to be weak for explaining the uncertainty and interactivity of traffic among links. This study tries to construct a traffic assignment model that is different from Wardrop’s in many aspects. First, it considers the cross-effect among the links. Second, a fuzzy travel cost function is established based on the possibility concept instead of precise calculation of traffic volumes. Third, the techniques of fuzzy measure and fuzzy integral are applied to calculate the subjectively perceived travel costs during traffic assignment. Furthermore, in order to validate our model, a detailed network with 22 nodes and 36 links is used to illustrate it. Study results show that our model explains more interactivity and uncertainty of traffic among links when compared with the traditional model of Wardrop’s.     

A Phenomenological Analysis of Higher Fock State Contributions to the χCJ Decays

We present a phenomenological analysis of higher Fock state contributions to the χ_CJ decays by using the recent BES experimental data.It is found that the higher Fock state |cc)8g〉 makes an important contribution to the inclusive and exclusive processes with respect to that from the valence Fock state |cc〉 of the χ_CJ and some constraints of these contributions are obtained for the χ_co and χ_c2 states in order to fit the experimental data.     

锂离子电池电解液中六氟磷酸锂浓度的离子色谱测定法

用离子色谱法测试锂离子电池电解液中的电解质(LiPF6)浓度,通过一系列条件实验确定了最佳前处理方式:选择逆王水作为分解处理剂;其用量与电解液等体积;作用时间在12 h以上,结果表明,F-和PO43-的回收率均达到100%以上,且根据PO3-计算得到的LiPF浓度相对误差为1.2%,具有较高的定量准确度。     

Quantum interference effects on the probe amplification without and with inversion in a four-level system

A four-level system driven by two coherent fields is considered. It is shown that in the presence of an incoherent pump, the probe gain at a short wavelength can be achieved due to the quantum interference. Our density matrix calculation provides the conditions for probe amplification from different origins, including gain without population inversion on any state basis, gain with population inversion on the dressed-state basis, and gain with population inversion on the bare-state basis. Also, by controlling the Rabi frequency of the coupling field a total change from non-inversion to inversion can be achieved which does not depend on the intensity of the incoherent pump.     

非等温TG- DTG法确定2,2'- 联吡啶- 对甲氧基苯甲酸铕(Ⅲ)热分解反应的机理函数和动力学参数

采用TG-DTG和DTA技术研究了2,2'-联吡啶-对甲氧基苯甲酸铕(Ⅲ)在静态空气中的非等温热分解过程及动力学,根据TG曲线确定了热分解过程中的中间产物及最终产物,运用微分法与积分法对非等温动力学数据进行分析,推断出第一步的动力学方程为dα/dt=Aexp(-E/RT)2(1-α)1/2.     

氧化锌包覆超细二氧化钛的制备及其紫外屏蔽性能

采用分步-均一沉淀法,以尿素为沉淀剂制备粒径为40nm的锐钛矿型二氧化钛超细粒子,并在其表面包覆晶体粒径为10.2nm的氧化锌,研究了不同含量的氧化锌对包覆效果及紫外吸收性能的影响.结果表明,合成的氧化锌包覆超细锐钛矿型TiO₂的紫外吸收性能明显高于锐钛矿型超细二氧化钛、金红石型二氧化钛及市售氧化锌.