Chloride Ion Transmission Model under the Drying-wetting Cycles and Its Solution

The chloride ion transmission model considering diffusion and convection was established respectively for different zones in concrete by analyzing chloride ion transmission mechanism under the dryingwetting cycles. The finite difference method was adopted to solve the model. The equation of chloride ion transmission model in the convection and diffusion zone of concrete was discreted by the group explicit scheme with right single point （GER method） and the equation in diffusion zone was discreted by FTCS difference scheme. According to relative humidity characteristics in concrete under drying-wetting cycles, the seepage velocity equation was formulated based on Kelvin Equation and Darcy＇s Law. The time-variant equations of chloride ion concentration of concrete surface and the boundary surface of the convection and diffusion zone were established. Based on the software MATLAB the numerical calculation was carried out by using the model and basic material parameters from the experiments. The calculation of chloride ion concentration distribution in concrete is in good agreement with the drying-wetting cycles experiments. It can be shown that the chloride ion transmission model and the seepage velocity equation are reasonable and practical. Studies have shown that the chloride ion transmission in concrete considering convection and diffusion under the drying-wetting cycles is the better correlation with the actual situation than that only considering the diffusion.

A Reflectron Time-of-Flight Mass Spectrometer with a Nano-Electrospray Ionization Source for Study of Metal Cluster Compounds

An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.

Fabrication of porous lithium titanate self-supporting anode for high performance lithium-ion capacitor

Lithium titanate has unique "zero-strain" characteristics, which makes it promising for rapid energy storage lithium-ion capacitors. However, extremely low electronic conductivity and lithium ion diffusion coefficient severely limit its performance at high rate. Herein, we have constructed in situ clusters of porous lithium titanate nanoparticles on self-supporting carbon nanotube film by combining iron oxide hard template method and F127 soft template method. Due to the nano-structured particle size and the penetrating lithium ion transmission channel, a greatly improved lithium ion diffusion coefficient has been achieved, which brings significantly better electrochemical performance than dense lithium titanate. By assembling with a durable graphene foam cathode, a lithium-ion capacitor with an energy density of up to 101.8 Wh kg-1 was realized(at a power density of 436.1 W kg-1). And its capacitance retention reaches 84.8% after 5000 cycles. With such an alluring result, our work presents a novel lithium-ion capacitor system with practical application prospects.

Simulations of guiding of low-energy ions through a single nanocapillary in insulating materials

Simulations of guiding of low-energy ions through a single nanocapillary in insulating polymers are reported. The nanocapillary has a diameter of 100 nm and a length of 10 μm. Different from previous work, in our simulations a hyperbolic function is used to describe the decay of the charges deposited on the capillary surface. The present simulations reproduce the self-organized charge-up process occurring in the capillary. It is shown that lower-energy ions undergo more oscillations to get guiding equilibrium than those of higher-energy ions, resulting in a longer charging time, which is in good agreement with previous experimental results. Moreover, the experimentally observed mass independence of ion guiding is proved in our simulations. In particular, it is found that the maximum of the repulsive field within the capillary is independent of the ion energy as well as the tilt angle. To counterbalance the increasing of the transversal energy caused by increasing the tilt angle or incident energy, the effective length of the repulsive field is expanded in a self-organizing manner.

中药内服联合中药离子导入治疗围绝经期膝骨性关节炎的疗效观察

目的:观察独活寄生汤联合中药离子导入治疗围绝经期膝骨性关节炎(KOA)的疗效观察,为中医药治疗围绝经期KOA提供参考。方法:选取2015年1月至2017年12月深圳市盐田区人民医院就诊的确诊为肝肾亏损证围绝经期KOA患者74例,随机分为对照组和观察组,对照组给予常规的西医治疗,观察组在对照组常规西医治疗的基础上加用独活寄生汤口服联合中药离子导入治疗。观察并比较两组治疗前后的临床疗效、中医证候积分、关节滑膜厚度、关节软骨厚度、关节腔积液评分、视觉模拟评分法(VAS)评分、西安大略和麦克马斯特大学(WOMAC)评分。结果:治疗后观察组的总有效率明显高于对照组,差异具有统计学意义(P<0.05);两组治疗后的中医证候积分、关节滑膜厚度、关节腔积液评分、VAS、WOMAC评分均较治疗前明显降低,差异具有统计学意义(P<0.05),且观察组降低程度明显优于对照组,差异具有统计学意义(P<0.05)。结论:中药内服联合中药离子导入可以提高围绝经期KOA的临床疗效,改善膝关节功能。