LaNi4.7Al0.3单颗粒微电极电化学行为的研究

报道了一种单颗粒微电极制备新方法, 并研究了LaNi4.7Al0.3球形单颗粒微电极的电化学行为.     

微机显微图象分析系统在推进剂研究中的应用

探讨了微机显微图象分析仪在测定超高燃速推进剂微孔结构方面的应用，并对推进剂固体粉末组分平均粒径及其分布进行了测定，还初步探索了测定推进剂制成品的断面结构状况，以判断工艺混合均匀性的可能。实际应用表明微机显微图象分析系统可以在推进剂的研究领域发挥很大的作用。     

Water erosion mechanism of mild carbon steels induced by micro-particles

To clarify the water erosion mechanism of the mild carbon steels, the water erosion experiments were performed by using deionized water as steam source. The results showed that under the damage threshold velocity of liquid impact, the material surface would not be destroyed. However, when the micro-particles were added into the steam, the pits appeared on the surface soon. By comparison, it is found that the pits are quite different from those induced by micro-particles impact without steam, but similar to those induced by cavitation erosion. The results indicated that the water erosion mechanism was similar to that of cavitation erosion under the damage threshold velocity. The micro-particles carry the micro-bubbles to approach the surface of the material, and the micro-bubbles collapse and generate micro-jet to impinge vertically on the surface, which lead to the produce of pits.     

金属材料动态损伤的微观数值模拟

针对金属材料的动态损伤现象，采用分子动力学方法对存在微观表面缺陷的材料在瞬态强冲击作用下的损伤情况进行数值模拟．模拟对象为铜材料，表面缺陷为锲形、圆形和方形沟槽，采用目前较为合理的嵌入原子势（EAM），并利用分子动力学程序（LAMMPS）进行动态数值模拟，有效地给出了存在不同微观表面缺陷的金属铜材料在瞬间强冲击作用下的损伤效应．结果表明，存在锲形缺陷的金属表面更容易发生微喷射现象，且微喷射速度随着锲形角增大而减小，随着冲击速率增大而增大。     

尘埃颗粒在射频等离子体鞘层中的非线性共振现象的理论研究

一种自洽的理论模型用于研究尘埃颗粒在射频鞘层中垂直方向的非线性共振现象.利用射频鞘层动力学模型，研究了鞘层电场和尘埃颗粒的充电过程.考虑作用在尘埃颗粒上的各种作用力(如重力、电场力、离子拖拽力、中性气体摩擦力及探针的扰动力)，并通过数值求解颗粒运动方程，模拟了该尘埃颗粒在探针扰动下的非线性振荡过程.所得结果不仅很好地再现了最近的实验观察，同时还发现这种非线性振动过程与等离子体参数、施加的射频偏压的功率、探针的扰动电位和位置等有着密切的联系. 关键词： 射频鞘层 尘埃颗粒 尘埃充电 非线性共振 迟滞     

Obituary Professor Danuta Bauman

Colloidal particles trapped at an interface between two fluids can form a wide range of different structures. Replacing one of the fluid with a liquid crystal (LC) increases the complexity of interactions and results in a greater range of possible structures. New behaviour emerges when colloidal particles interact with defects in the LC phases. Here, we discuss the templating of colloids at a cholesteric isotropic interface.     

壳聚糖纳微粒棉织物表面平衡吸附研究

通过热重分析法(TGA)系统地研究了不同温度下壳聚糖纳微粒(CNs)在棉织物表面的平衡吸附行为,并借助Langmuir、Freundlich及Dubinin-Radushkevich等温模型拟合曲线计算了吸附过程热力学参数。结果发现,三种等温吸附模拟均可对CNs棉织物表面平衡附着行为进行一定程度地描述,且在5~75℃下无交联剂吸附过程的标准吉布斯自由能变(ΔGo)、焓变(ΔHo)及熵变(ΔSo)均小于0,表明CNs在棉织物表面的附着行为是一个自发、放热且体系混乱度降低的过程。同时随着温度的降低,吸附过程的平均附着能(E)及ΔGo绝对值均不断增大,表明温度下降有利于吸附反应的进行,CNs与棉织物间的结合作用增强,且逐渐表现出化学吸附特性。     

Liquid chromatography with diode array detection and multivariate curve resolution for the selective and sensitive quantification of estrogens in natural waters

Following the green analytical chemistry principles, an efficient strategy involving second-order data provided by liquid chromatography (LC) with diode array detection (DAD) was applied for the simultaneous determination of estriol, 17β-estradiol, 17α-ethinylestradiol and estrone in natural water samples. After a simple pre-concentration step, LC–DAD matrix data were rapidly obtained (in less than 5 min) with a chromatographic system operating isocratically. Applying a second-order calibration algorithm based on multivariate curve resolution with alternating least-squares (MCR-ALS), successful resolution was achieved in the presence of sample constituents that strongly coelute with the analytes. The flexibility of this multivariate model allowed the quantification of the four estrogens in tap, mineral, underground and river water samples. Limits of detection in the range between 3 and 13 ng L⁻¹, and relative prediction errors from 2 to 11% were achieved.     

用微米级LaNi5为催化剂生长的碳管的ESR谱研究

用微米级LaNi₅合金粉末为催化剂, 以乙炔为原料, 采用化学气相沉积(CVD)法合成了多壁碳纳米管. 在100~290 K温度下测量了41 μm≤d≤150 μm粒径催化剂制备的不同直径分布的碳纳米管的电子自旋共振（ESR）谱,研究了测量温度、微米级催化剂粒径及制备过程的氢气氛对生成的碳纳米管的ESR谱线型、g因子、线宽的影响. 发现碳纳米管的g因子随其直径的增大而增大,分别为2.040 0（催化剂粒径41 μm≤d≤50 μm, 碳纳米管的直径分布为10 nm到20 nm）和2.089 8（催化剂粒径100 μm≤d≤150 μm,碳纳米管的直径分布为70 nm到120 nm）. 发现小管径纳米管的ESR谱图有一个峰, 而大管径纳米管的ESR谱图有两个峰A和B, 且随测量温度的升高, 峰B强度增大.     

微颗粒黏附力测试技术研究进展

 为了解微颗粒黏附力测试技术的研究进展,以Particle、Adhesion、Measurement为主题词,在Ei Compendex,Ei Inspec和Elsevier Science数据库中检索了2001—2010年收录的文献,共检索出150余篇有关微颗粒黏附力测试技术的文献。根据这些文献的发表时间、作者所属的国家和所研究的测试技术进行了统计分析。对各种微颗粒黏附力测试技术(AFM分离技术、微机械分离技术、离心分离技术、静电场分离技术、振动分离技术和激光分离技术)进行了分析和优缺点比较,并展望了该领域发展的前沿方向。