二维熔化的研究进展

晶体的熔化一直是凝聚态物理中广泛关注的研究方向,尽管有上百年的研究历史,但是仍然没有一个完整的基础层面上的理论。大量实验和计算模拟研究工作表明,熔化符合KTHNY理论。晶体在熔化过程中的结构和动力学也已成为大家关注的热点。     

Formation and stability of emulsions stabilised by Yucca saponin extract

Yucca saponin extract containing steroidal saponins was examined for its interfacial and emulsifying properties. For this purpose, we produced oil‐in‐water emulsions and tested their stability against environmental stresses (pH, ionic strength, heating and freeze‐thawing). Yucca saponin extract was highly surface‐active and formed negatively charged submicron‐sized emulsions at low surfactant‐to‐oil ratio. The emulsions were stable at pH 5–9 and showed only minor increase in droplet size when heated up to 90 °C. Our results indicate Yucca saponin extract as a new potential natural surfactant that may be used to replace synthetic surfactants in the food and beverage industry for selected applications.     

表面电位及中性油的分散度对矿粒与油滴之间作用能的影响

本文根据胶体与表面化学理论研究了表面ξ—电位及中性油的分散度对辉钼矿、石墨、滑石等天然疏水性矿粒与油滴之间作用总能的影响。     

Investigation and application of polysiloxane-based gel electrolyte in valve-regulated lead-acid battery

Polysiloxane-based gel electrolyte (PBGE) is prepared and investigated as a new gel electrolyte for valve-regulated lead-acid (VRLA) batteries. PBGE particles, characterized by means of Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV) and scanning electron microscopy (SEM), reveal good stability and their particle sizes are 30–50 nm. The initial cyclic properties of the absorptive glass mat (AGM)–PBGE and AGM–colloid silica gel electrolyte (CSGE) hybrid batteries are investigated by electrochemical techniques, scanning electron microscopy and X-ray diffraction (XRD). The addition of PBGE improves the utilization efficiency of positive active material (PAM) in AGM–PBGE hybrid batteries and thus enhances the batteries capacity compared with the AGM–CSGE reference batteries. Cyclic overdischarge tests show that the AGM–PBGE hybrid batteries have superior recharge and discharge during partial-state-of-charge (PSoC). It is also found that the greatly enhanced electrochemical performance of the AGM–PBGE batteries may be due to higher charge efficiency, good conductivity with lower internal resistance and the open three-dimensional network structure of the polyelectrolyte. The analysis results of SEM and XRD indicate that softening and shedding of positive active material are the main causes of failure for the two hybrid batteries.     

胶体粒子扩散聚集过程的二维动态化模拟

简要地报道了用ＦＯＲＴＲＡＮ语言实现胶体粒子扩散聚集过程二维动态模拟的一种简单方法：将二维平面划分为网络,胶体粒子按一定的浓度和能量随机分布在网络格点上;调用着色子程度设定背景和绘图颜色;对某一时刻各胶体粒子所占位置进行屏幕点和着色操作;计算下一时刻各粒子的位置坐标;取消上一时刻各粒子,即置其位置为背景色;根据所计算出的新时刻的粒子坐标进行画点着色;重复上述过程至体系达某一状态或某一时刻。由于计算     

Molecular dynamics simulation of the forces between colloidal nanoparticles in Lennard–Jones and <Emphasis Type=Italic>n</Emphasis>-decane solvent

Molecular-dynamics is utilized to simulate solvation forces between two nanoparticles immersed in two different solvents: Lennard–Jones spheres and and n-decane. Three different sizes and shapes of solvophilic nanoparticles are investigated. Nanoparticles in the Lennard–Jones liquid exhibit solvation forces that oscillate between attraction and repulsion as the nanoparticle separation increases. The magnitude of these solvation forces increases with particle size and depends on particle shape, consistent with the Derjaguin approximation. When n-decane is the solvent, the solvation forces are negligible for small nanoparticles, with sizes comparable to the end-to-end distance of all-trans decane. The solvation forces oscillate between attraction and repulsion for sufficiently large nanoparticles in decane—however the Derjaguin approximation does not appear to be effective at describing the dependence of nanoparticles forces on nanoparticle size and shape when decane is the solvent. For both the Lennard–Jones and n-decane solvents, it is apparent that the force profiles are influenced by the surface roughness of the nanoparticles. These factors should be taken into account in efforts to engineer colloidal suspensions.     

Colloid stabilization by polyelectrolytes. Application to decontamination processes of nuclear reactors

The redeposition of colloidal magnetite particles can reduce the effectiveness of the chemical decontamination of nuclear reactors. Sodium salts of the following anionic polyelectrolytes were evaluated as particle stabilizers: polyacrylic acid, polymethacrylic acid, poly (methyl vinyl ether/maleic anhydride), sulfonated polymers. A cationic polyelectrolyte, a polyamine, was also evaluated. An active and an inactive oxidized carbon steel sample were treated in the same experimental set-up with the decontaminating reagent and with or without the polyelectrolyte. Activity pick-up by the inactive sample was measured. When no polyelectrolyte was added, 15% of the Co-60 activity was redeposited. With polyelectrolyte addition in the 5–450 mg kg^?1 range, the Co-60 activity redeposition ranged from 8.5 down to 0.8%. Polyacrylic acid was the most effective reagent. The transfer of the magnetite outer oxide crystals from the active to the inactive surfaces was identified on SEM micrographs.     

50％硫胶悬剂的研制

本文详细介绍了50％硫腔悬剂的制造方法及对产品进行质量评价的方法。     

胶体铅蓄电池中电解质特性研究

本文介绍了一种新型蓄电池——胶体铅政蓄电池的工作原理和主要特点，并对其中的肢体电解质某些特性作了初步地研究．