金属盐作用下的表面活性剂临界胶束浓度的变化研究

用电导法系统地研究了金属离子－－Cu(Ⅱ），Zn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),La(Ⅱ)和Fe(Ⅲ）对两种离子型表面活性剂－－十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（CTAB）的临界胶束浓度（CMC）的影响，并推导了一系列表达金属离子浓度和表面活性剂SDS及CTAB的临界胶束浓度(CMC）之间关系的经验公式。结果表明，SDS和CTAB的临界胶束浓度(CMC)均随着金属离子浓度的增加而减小，这些现象可以用反离子效应和熵驱动效应来解释。     

星载激光测高仪海面回波的仿真与分析

星载激光测高仪发射的1 064 nm波长激光被波动海洋表面反射,系统接收的时间波形与瞬时海面波浪分布相关。而海面波浪又直接受海面风速影响,因此可以通过观测激光测高仪回波变化监测不同风速下海态变化。本文依据激光雷达方程,利用蒙特卡洛法模拟不同风速下的海面波浪分布,通过光线追击建立海面回波波形仿真器;以地球科学激光测高系统(geo-science laser altimeter system,GLAS)参数为输入,仿真得到不同风速下的海面回波:发现当海面风速在3~10 m/s之间时,回波呈单峰高斯波形,与GLAS发布的实际回波相符;且回波脉宽,以及有效能量反射率(即有效回波能量与发射能量之比)与实测参数误差小于10%。进一步分析可知,回波特征参数与海面风速之间存在显著关联,为利用激光测高仪大规模精确反演海洋表面风速奠定了基础。     

发动机变组分煤层气的起动特性与怠速稳定性

由于石油资源的逐渐枯竭和排放法规的日益严格,使燃用代用燃料发动机在全世界得到广泛地发展。文章介绍了由S195柴油机改制成火花点火式变组分煤层气发动机的主要设计过程,分析了此类型发动机在改制过程中应注意的几个问题。通过发动机台架试验,对起动特性与怠速稳定特性进行分析,结果令人满意。     

Rotational CARS N2 thermometry: validation experiments for the influence of nitrogen spectral line broadening by hydrogen

Rotational coherent anti‐Stokes Raman spectroscopy (CARS) in fuel‐rich hydrocarbon flames, with a large content of hydrogen in the product gases (∼20%), has in previous work shown that evaluated temperatures are raised several tens of Kelvin by taking newly derived N₂ H₂ Raman line widths into account. To validate these results, in this work calibrated temperature measurements at around 300, 500 and 700 K were performed in a cell with binary gas mixtures of nitrogen and hydrogen. The temperature evaluation was made with respect to Raman line widths either from self‐broadened nitrogen only, N₂ N₂ [energy‐corrected‐sudden (ECS)], or by also taking nitrogen broadened by hydrogen, N₂ H₂ [Robert–Bonamy (RB)], Raman line widths into account. With increased amount of hydrogen in the cell at constant temperature, the evaluated CARS temperatures were clearly lowered with the use of Raman line widths from self‐broadened nitrogen only, and the case with inclusion of N₂ H₂ Raman line widths was more successful. The difference in evaluated temperatures between the two different sets increases approximately linearly, reaching 20 K (at T ∼ 300 K), 43 K (at T = 500 K) and 61 K (at T = 700 K) at the highest hydrogen concentration (90%). The results from this work further emphasize the importance of using adequate Raman line widths for accurate rotational CARS thermometry. Copyright © 2010 John Wiley & Sons, Ltd.     

双面加热环形通道内干涸点的确定

根据环形管通道内流体流动和换热的特点,以Kirillov和Smogalev提出的干涸点理论模型假设为基础,从最基本的质量守恒方程出发,并引入临界液膜厚度等相应的辅助模型,得到了双面加热环形通道内流动沸腾干涸点的理论模型。同时针对间隙为1.0mm和1.5mm的环形窄缝进行了低压低质量流速工况下干涸点的实验研究。比较发现理论模型预测值与实验结果基本相符。说明本文提出的理论模型适用于低压低流量条件下的窄环形通道。实验同时发现:环状流临界热流密度在系统压力为2.2MPa达到最大值,临界含汽量随质量流速的增大呈缓慢下降趋势。     

临界装置实验大厅散射中子分布研究

采用蒙特卡罗方法,通过MCNP5程序对实验大厅内不同散射体产生的散射贡献及散射中子分布进行了计算。结果表明,散射中子强度随离开临界中子源距离先呈减小趋势,在接近大厅墙壁处则出现增加,呈现明显的W形状。同时设计并验证了模拟结果的正确性,结果表明模拟计算与实验测量结果的趋势相同,证明了计算结果的可靠性。     

Infinite propagation speed of the Camassa-Holm equation

We use the inverse scattering transform to show that a solution of the Camassa-Holm equation is identically zero whenever it vanishes on two horizontal half-lines in the x-t space. In particular, a solution that has compact support at two different times vanishes everywhere, proving that the Camassa-Holm equation has infinite propagation speed.     

Phase‐separated,conducting composites from polyaniline and benzobisthiazole rigid‐rod polymer

As an alternative method for processing polyaniline (PANI) from its conducting (protonated) state, vacuum casting of PANI from a methanesulfonic acid (MSA) solution provided films with electrical conductivity values of about 130–150 S/cm. In addition, we similarly prepared blended films of PANI · MSA and poly(p‐phenylene benzobisthiazole) (PBZT). This process eliminated the need for a subsequent protonation step and had the additional advantage that the conjugated PBZT may provide alternative conducting pathways. Conductivity values of the composite films ranged from 100 pS/cm to 124 S/cm, and the films displayed critical concentration behavior with a PANI threshold concentration of 2.75% and a critical exponent of 4. Transmission electron micrographs displayed phase‐separated regions with PANI forming a continuous network at high concentrations. Thermogravimetric analysis results demonstrated the thermal and thermooxidative stability advantage of the blends due to the PBZT component. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2539–2548, 2001     

Supramolecular control over LCST behavior of hybrid macrocyclic system based on pillar[5]arene and crown ether

A hybrid system containing a pillar[5]arene unit and ten crown ether moieties was developed. The LCST behavior and thermo-responsiveness were successfully introduced into this pillar[5]arene-crown ether system. Both host-guest interactions and salting-out effect displayed great effects in realizing the supramolecular control over LCST properties and thermo-responsiveness. Compared with the individual macrocycles, this hybrid macrocycle system dramatically amplified the supramolecular control effect over LCST behavior.     

湿式除尘器中脱水装置性能的理论和实验

详细分析了湿式除尘器中脱水装置的脱水机理,并对脱水装置性能进行了实验研究,建立了脱水装置的极限风速和阻力系数与液气比有关的经验和半径验公式,为研究和设计其他类型的脱水装置提供理论依据和实验数据。