Investigation of the Li1+xV3O8 electrode–organic electrolyte interface by scanning photoelectron microscopy

To investigate the formation of a solid electrolyte interface (SEI) on the Li_1+xV₃O₈ electrode surface in the thermodynamic stability range of the organic electrolyte, we applied scanning photoelectron microscopy (SPEM) to a pristine electrode and to an electrode after ten cycles. The F K-edge absorption spectrum of the cycled electrode showed that LiF forms on the electrode surface during the lithium insertion–extraction process in the Li_1+xV₃O₈/Li cell. The photoelectron spectrum for the cycled electrode showed intense spectral features corresponding to Li 1s, F 2s, F 2p, and P 2p electron signals, whereas these spectral features were of negligible intensity for the pristine electrode. The above results give strong support for the formation of an SEI that consists of LiF and compounds containing phosphorus during operation of the battery. The SPEM images also revealed that the fluorine distribution on the surface of the cycled electrode was inhomogeneous.     

ICP-AES同时测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴

采用ICP－AES法测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴元素含量，并对样品的溶解酸和酸用量、元素分析线的选择以及共存元素间的干扰进行了研究。该法简便、快速，精密度和准确度较好。     

Vibsanin O, a novel diterpenoid from Viburnum awabuki

Vibsanin O, isolated from the leaves and twigs of Viburnum awabuki, is an unprecedented bicyclic diterpenoid. The structures of vibsanin O was established by extensive analysis of spectroscopic data.     

Excitons in coupled quantum dots

Properties of excitons in vertically coupled GaAs/AlGaAs quantum dots were investigated using the variational method within the envelope function and effective mass approximations. It was found that when the thickness of the spacer layer becomes less than about one exciton Bohr radius, both the exciton binding energy and the fundamental optical transition energy are reduced compared to those in isolated quantum dots. This is a result of increased space extension of exciton due to the penetration of carrier wave functions into the spacer layer and corresponding reduction in confinement energy which dominates over the Coulomb interaction between the electron and the hole.     

Sr2RuO4的热电势

Sr2RuO4是第一个无CuO面的层状强关联氧化物超导体.测量了9至260K温度范围内Sr2RuO4的热电势,观测到在此温度范围内其热电势为正值.用两种载流子模型对实验数据进行了拟合,并且与Hall系数的实验结果进行了比较,发现低温下两种载流子对热电势和Hall系数的贡献比较类似,但在高温区空穴对热电势的贡献很大而相应地对Hall系数的贡献不占主要地位. 关键词： Sr2RuO4 热电势     

锂锰尖晶石红外光谱的研究

本文对锂锰尖晶石的红外光谱进行了研究。由于锂锰尖晶石的晶体结构属于Fd3m空间群,锂离子占据四面体空隙(8a位置),锰离子占据八面体空隙(16d位置)。根据群论的知识,对锂锰尖晶石晶体中离子的振动方式与红外活性之间的内在关系进行了讨论。并列出了锂锰尖晶石的红外光谱实验数据。通过理论分析,我们推断:位于618.6和501.5cm~(-1)的红外吸收带分别来源于Mn(Ⅳ)-O和Mn(Ⅲ)-O键在晶体中的不对称伸缩振动(单元为Mn(Ⅳ)O_6和Mn(Ⅲ)O_6八面体),位于1124cm~(-1)的弱红外吸收带来源于Li-O键的不对称伸缩(单元为LiO_4四面体)。还有一些低于400cm~(-1)的可能吸收带在400～4000cm~(-1)范围内未能检测到。这一结论的可靠性通过锂锰尖晶石和掺杂的锂锰尖晶石的红外光谱实验数据得到证实。     

深紫外无机非线性光学晶体硼铍酸锶及其分子工程学探索方法

阐述了紫外无机非线性光学晶体分子工程学探索方法的基本特点，具体分析深紫外无机非线性光学晶体硼铍酸锶（ＳＢＢＯ）以氟硼铍酸钾（ＫＢＢＦ）为主要参考晶体的分子设计方法，随后根据晶体结构研究、单晶培养、和非线性光学性能测定等实验结果讨论ＳＢＢＯ作为新型深紫外无机晶体的主要优点，即它既具有更短的紫外吸收边（接近１５５ｎｍ）和较大的非线性光学系数（ｄ２２（ＳＢＢＯ）＝０６×ｄ２２（ＢＢＯ）＝１３８ｐｍ／Ｖ），同时晶体无明显层状习性，并肯有良好的化学稳定性和机械性能     

Cr^4＋：YAG,Cr^4＋：Mg2SiO4近红外荧光辐射温度特性研究

测量了Ｃｒ＾４＋，ＹＡＧ、Ｃｒ＾４＋，Ｍｇ２ＳｉＯ４晶体在室温和液氮温度下的荧光光谱，吸收光谱和激发态寿命，讨论了温度变化时，两种晶体中Ｃｒ＾４＋近红外辐射积分强度变化与激光发态寿命变化的关系，得出结论：在７７Ｋ￣３００Ｋ范围内，Ｃｒ＾４＋的＾３Ｔ２能级荧光辐射截面本身受温度影响不大，Ｃｒ＾４＋辐射荧光的变化，主要是由无辐射弛豫速率随温度变化而引起的。     

On the possibility of designing interacting semiconductor quantum wells with zero perturbation coupling

The paper describes the possibility of designing matched interacting semiconductor quantum wells. It is shown that for a given eigenstate of a quantum well (QW), it is always possible to find another QW in such a way that the coupling leaves the original eigenstate of the host QW unperturbed irrespective of the strength of interaction. For rectangular QWs, the condition is met with whenever the second QW has appropriate width and depth so that phase travelled by an electron wave through it is an integral multiple of π.     

Tunneling of two interacting electrons in a quantum wire

A model calculation is reported for the tunneling probability of one as well as two interacting electrons from a quantum well within a narrow channel. We discuss the cases when the two electrons are spin polarized or unpolarized by transforming the system to a noninteracting one with the use of quantal density functional theory to obtain an effective single-particle confining potential. A semiclassical approach is used to obtain the tunneling probability from this effective potential. The calculation is motivated by recent measurements of the conductance of an electron gas in a narrow channel but is not meant to explain the anomalous behavior that has been reported since, for example, we deal with a simplified two-level system. Numerical results for the tunneling probability are presented.