Optical bistability based on surface plasmon coupled between two noble metal films involving Kerr materials

We successfully investigate an optical bistability phenomenon in a layered structure consisting of Kretschmann configuration involving the Kerr-type nonlinear and the silver film. Pure theoretical approaches are employed to investigate that the surface plasmon could easily be coupled and both the reflection and transmission curves versus the incident intensity forms optical bistability. The transmission curves are greatly influenced by the thickness of the second silver film. These results may be useful for designing novel surface plasmon-based optical devices and will be essential for future classical and quantum information processes.     

A study on the interior microstructures of working Sn particle electrode of Li-ion batteries by in situ X-ray transmission microscopy

The interior microstructures of Sn particles developed during electrochemical lithiation/de-lithiation have been revealed by in situ X-ray transmission microscopy (TXM). The Li-alloying particles exhibited the formation of core–shell internal structure along with crack formation within the lithiated zone during the first lithiation. The extent and speed of the expansion process was shown to be a strong function of particle size. Upon completion of the first de-lithiaiton, the particles only partially (～10%) contracted, while re-crystallization of Sn continued to take place within the interior of the particles during a following idle period. The re-crystallization process alleviated the pulverization problem and led to the formation of porous Sn particles, which exhibited remarkably attenuated dimensional variations during subsequent cycles.     

Decomposition of High Concentration Hydrogen Peroxide over Alumina-Supported Lao.6Sr0.4MnO3 Perovskite Catalyst

In recent years there has been ever-increasing interest in space propellants that are more environmentally benign,less toxic and easier and safer to handle than conventional ones     

Synthesis and fungicidal activity of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines

A number of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines were synthesized.The structures of these new compounds were confirmed by ~1H NMR,IR and elemental analysis.Biological evaluation in the greenhouse showed several compounds have good fungicidal activities at 25 mg/L.     

SH15树脂吸附胞二磷胆碱的热力学及动力学研究

静态条件下,研究了SH15树脂吸附水溶液中胞二磷胆碱(CDPC)的热力学和动力学特性.测定了不同温度下,热力学性质的变化.实验结果表明,SH15树脂对CDPC吸附平衡数据符合Langmmuir吸附等温方程,吸附过程为自发的物理吸附过程.考察了温度、溶液浓度、树脂粒径和搅拌速率对吸附过程的影响.运用动边界模型(MBM)描述了SH15树脂吸附CDPC的动力学过程,确定在实验条件范围内,SH15树脂吸附CDPC的吸附速度受颗粒扩散控制,并计算出吸附过程的表观活化能为9.73kJ/mol,反应级数为0.47,速率常数为0.0744,并推导出CDPC:在SH15树脂上的动力学总方程.     

A volume-amending method to improve mass conservation of level set approach for incompressible two-phase flows

A volume-amending method is developed both to keep the level set function as an algebraic distance function and to preserve the bubble mass in a level set approach for incompressible two-phase flows with the significantly deformed free interface. After the traditional reinitialization procedure, a vol-ume-amending method is added for correcting the position of the interface according to mass loss/gain error until the mass error falls in the allowable range designated in advance. The level set approach with this volume-amending method incorporated has been validated by three test cases: the motion of a single axisymmetrical bubble or drop in liquid, the motion of a two-dimensional water drop falling through the air into a water pool, and the interactional motion of two buoyancy-driven three- dimensional deformable bubbles. The computational results with this volume-amending method in-corporated are in good agreement with the reported experimental data and the mass is well preserved in all cases.     

Giant Nonlinear Absorption by an Ensemble of Metallic Grains

We have investigated the nonlinear low-frequency microwave absorption of an ensemble of small metallic grains. Earlier Zhou et al. [Phys. Rev. Lett. 77, 1958 (1996)] have proved that linear absorption by such a system is due to a mesoscopic relaxation mechanism for which important contribution is from the grains with small level spacings between the ground state and the first excited state. Here we have shown further that such grains are anomalously sensitive to the field amplitude and the distribution of level spacings. Since such a behavior depends on external magnetic field, we expect the appearance of a giant nonlinear magnetoresistance, as well as a very strong temperature dependence of the nonlinear microwave conductivity.     

对叔丁基杯[8]芳烃酯类衍生物的合成方法改进及其对酯型儿茶素的萃取性能

以酰氯为酰基化试剂,用三乙胺作缚酸剂和催化剂,制备了一系列对叔丁基杯[8]芳烃酯类衍生物(2a～2e),其结构经1H NMR, IR和元素分析表征.以2为萃取剂,考察了酯型儿茶素单体在二氯甲烷-水两相体系中的萃取分配行为.结果表明:2e的萃取效果最佳.     

Non‐Alkaloidal Constituents from the Stem of Ficus Septica

Seven triterpenes, two lignans, and twelve other known compounds were isolated from the non‐alkaloidal fractions of the stem of Ficus septica Among these triterpenoids, a rare triterpene skeleton derivative, 13,27‐cycloursan‐3β‐ylacetate was isolated from natural sources for the first time. All the structures of these compounds were elucidated by spectroscopic methods.