ICF靶丸中液氢层厚度的确定

 利用靶丸内部的质量守恒，提出了计算惯性约束聚变靶丸内液氢层厚度的函数关系式，从而得到了求解惯性约束聚变靶丸内液氢层厚度的一般模型，并在此基础上对影响液氢层厚度的各类因素如温度、充气密度等进行了讨论。该模型的分析方法同样适用于惯性约束聚变中的燃料气体氘、氚或者氘氚混合物。     

Medium-range structural order in liquid Ni20Al80 alloy: Experimental and molecular dynamics studies

In this Letter, structural properties of liquid Ni₂₀Al₈₀ have been studied through molecular dynamics (MD) simulations, and results agree well with X-ray experiments. The prepeak in the structure factor manifests the existence of medium-range structural order (MRSO) in liquid Ni₂₀Al₈₀. Analyses in MRSO reveal the dominance of ideal icosahedra and defective icosahedra which, furthermore, form clusters and share common atoms.     

Planar nematic anchoring on SiO-coated substrates

Summary The nematic planar anchoring is usually explained by using simple elastic models: the surface easy axis corresponds to the surface direction that minimizes the excess of nematic elastic energy. When anisotropic rough substrates are used to align nematic liquid crystals, due to the complex surface morphology, usual elastic models are not directly applicable. This paper presents quantitative topographical data of rough substrates, obtained with oblique SiO evaporation under vacuum for nematic planar anchoring. Experimental data are obtained by means of Atomic Force Microscopy and they are used to demonstrate the self-affine nature of these substrates and to relate the nematic anchoring with the anisotropy of the local fractal properties of the substrate itself. Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994.     

Liquid crystal lens with focus movable in focal plane

A liquid crystal lens with focus movable in the focal plane is reported. There are three electrodes in the cell. One electrode with a hole in the center is divided into four subelectrodes. The potential of each subelectrode is adjusted to produce a desired asymmetrical phase transformation resulting in off-axis movement of the focus. The potential of another electrode is adjusted to maintain the focus in the focal plane. Movements of the focus in three directions in the focal plane are demonstrated experimentally, and off-axis movement as large as approximately 800 μm is realized.     

Electro-optical performance of polymer stabilized cholesteric texture cell: The influence of chiral dopant and monomer concentration

Reverse-mode polymer stabilized cholesteric texture (PSCT) cells with various chiral dopant and monomer concentrations were fabricated. Experimental results indicate that the chiral dopant concentration and the monomer concentration significantly influence the threshold voltage and hysteresis of the cells. The chiral dopant and monomer deform the hysteresis loop. Increasing the monomer concentration reduces the width of the hysteresis loop of the reverse-mode PSCT cell.     

Thermodynamic and surface properties of Sb-Sn and In-Sn liquid alloys

The thermodynamic properties of Sb-Sn and In-Sn liquid alloys have been studied using the quasi-chemical model for compound forming binary alloys and that for simple regular alloys. The concentration fluctuation S _cc(0) and the Warren-Cowley short-range order parameter (α ₁) were determined for the whole concentration range at a temperature of 770 K. The surface tensions of these liquid alloys were determined for the whole concentration range by using energetics determined from thermodynamic calculations. In all calculations, In-Sn manifested properties very close to alloys of ideal mixing, while Sb-Sn showed properties that are asymmetric about equiatomic composition. Our results suggest that a weak complex of the form SbSn₂ could be present in the Sb-Sn alloy at a temperature of about 770 K.     

The crystal structure on the set of Mirkovi?-Vilonen polytopes

In an earlier work, we proved that MV polytopes parameterize both Lusztig's canonical basis and the Mirkovi?-Vilonen cycles on the affine Grassmannian. Each of these sets has a crystal structure (due to Kashiwara-Lusztig on the canonical basis side and due to Braverman-Finkelberg-Gaitsgory on the MV cycles side). We show that these two crystal structures agree. As an application, we consider a conjecture of Anderson-Mirkovi? which describes the BFG crystal structure on the level of MV polytopes. We prove their conjecture for sln and give a counterexample for sp₆. Finally we explain how Kashiwara data can be recovered from MV polytopes.     

Electroanalytical and chromatographic determination of pentachlorophenol and related molecules in a contaminated soil: a real case example

Electroanalytical and chromatographic methodologies have been applied for the determination of pentachlorophenol (PCP) and some of its derivatives in real soil samples contaminated by industrial discharge. The analytes were extracted with hexane from soil samples collected at different points of the site and mixed to produce a representative sample. Square wave voltammetry (SWV) experiments were carried out on either a boron-doped diamond (BDD) electrode or a gold ultramicroelectrode (Au-UME) in an analyte composed by the Britton-Robinson (B-R) buffer at pH 5.5 with the direct addition of proper amounts of the extract. The voltammetric responses revealed an irreversible anodic peak at approximately 0.80 V vs. Ag/AgCl with a peak current showing a linear dependence on PCP concentration. This linear relationship yielded a detection limit (DL) of 2×10⁻⁸ mol l⁻¹ (or 5.5 μg l⁻¹) for the BDD electrode and 6.9×10⁻⁸ mol l⁻¹ (18.4 μg l⁻¹) for the Au-UME, while the independently measured HPLC detection limit was 1.1×10⁻⁸ mol l⁻¹ (3.0 μg l⁻¹). The application of electroanalytical and chromatographic methodologies in the analysis of soil extracts revealed, besides the PCP responses, signals for some related molecules such as o-tetrachlorobenzoquinone (o-chloranil), hexachlorobenzene and tetrachlorophenol. Recovering experiments for PCP showed a concentration of 27.5 mg kg⁻¹ for the electroanalytical determinations and 26.8 mg kg⁻¹ for the HPLC analysis, values exceedingly high if considering that the maximum residue limit established for natural waters by the Brazilian Environmental Agency is 10 μg l⁻¹.     

液晶研究（Ⅰ）──4＇－酰基－4－羟基－1，1＇－联苯酯类液晶的合成与性质

以４＇－羟基联苯为原料合成了８种新型４＇－酰基－４－羟基联苯酯类化合物．除化合物５＿ｈ外，均为新的近晶相液晶化合物．它们具有较宽的相变温度范围和较高的热稳定性．用偏光显微镜和差热分析仪研究了它们的相行为，讨论了分子结构对液晶相行为的影响．     

外电场下光聚合反应动力学的表征方法

外电场下光聚合反应动力学的表征方法李从武，潘昂上海材料研究所，上海２０００８２）关键词光聚合反应、液晶、外电场、动力学、表征近年来，液晶单体在外场（电场、磁场和剪切力）下在位光聚合反应的研究工作受到了很大的关注［’，ＺＩ．众所周知，热致型侧链高分子液...