CAU9901的高效液相色谱分析

报道了新型植物生长调节剂CAU9901的高效液相色谱分析方法。该方法快速简捷,精密度变异系数为0.49%,相关系数为1.000 4,准确度回收率在98.89%~100.1%之间。     

5-烷基-2-氨基-1,3,4-噻二唑的合成及应用

用硫代氨基脲与甲酸、乙酸、丙酸、丁酸、异丁酸、异戊酸等在盐酸、磷酸、多聚磷酸、硫酸催化下 ,分别合成了 2 -氨基 -1 ,3 ,4-噻二唑 (a)、5 -甲基 -2 -氨基 -1 ,3 ,4-噻二唑 (b)、5 -乙基 -2 -氨基 -1 ,3 ,4-噻二唑 (c)、5 -丙基 -2 -氨基 -1 ,3 ,4-噻二唑 (d)、5 -异丙基 -2 -氨基 -1 ,3 ,4-噻二唑 (e)、5 -异丁基 -2 -氨基 -1 ,3 ,4-噻二唑 (f)。并对工艺条件进行了试验 ,结果表明 :最佳工艺条件为硫代氨基脲与酸的摩尔比为 1∶ 1 .4,合成 2 -氨基 -1 ,3 ,4-噻二唑为多聚磷酸催化 ,合成其它的为浓盐酸催化 ,回流 3 h,产率分别为 96.78%、74.3 4%、73 .67%、71 .68%、68.44%、67.5 4%。同时以 a～f为原料合成了具有抗菌作用的 5 -烷基 -1 ,3 ,4-噻二唑硫脲乙酸和 5 -烷基 -2 -苯基 -硫脲 -1 ,3 ,4-噻二唑的衍生物     

MICROSCOPIC SPREADING CHARACTERISTICS OF NONPOLAR PERFLUOROPOLYETHER FILMS

The surface diffusion characteristics of nonpolar perfluoropolyether (PFPE) Z on carbon surfaces are investigated in two regimes, submonolayer and multilayer, for nano-thin films. For the submonolayer regime, the two-dimensional, cubic van der Waals equation of state is applied to determine the dependence of the surface diffusion coefficient on the film thickness, as experimental surface diffusion coefficients increase with increasing film thickness. For the multilayer regime, a conventional fluid mechanics analysis with position dependent viscosity and a van der Waals disjoining pressure gradient is applied to investigate the surface diffusion characteristics. The present theoretical analysis qualitatively agrees with the experimental results.     

Numerical Simulation of Oil‐water Hydrocyclone Using Reynolds‐Stress Model for Eulerian Multiphase Flows

A three‐dimensional oil‐water turbulent flow and oil separation process in a double‐cone liquid‐liquid hydrocyclone (LLHC) is numerically simulated using FLUENT software. The Euler‐Euler approach and Reynolds‐stress model are combined and adopted in this simulation to handle the challenging situation of anisotropic turbulent two‐phase flow with a higher volumetric ratio (over 10%) in the dispersed phase. It is visualized well in the simulation how separation, aggregation and shift of oil and water proceed in the LLHC. The oil separation efficiency is determined based on flow field and phase concentration distribution. The simulation is verified by comparing predicted and measured separation efficiency in the LLHC.     

Measurement of minimum angle of resolution (MAR) in the stereoscopic display using the optotype of stereoscopic stimuli

In stereoscopic images, the crossing point of the viewing directions of the two eyes determines the perceived depth. Assuming that accommodation is affected by the positions of the crossing point, the effect of crossing point on minimum angle of resolution (MAR) was investigated. For 40 participants, MAR was measured by two‐alternative forced choice where Snellen optotype E of up and down directions were used as two kinds of stimuli. As the crossing point of the viewing direction of the left and right eyes moves farther from the sample display, the ability to identify the direction of letter E decreases at the optotype of the same line thickness. The change of MAR shows linear trends with respect to the optical power change that are the reciprocal of the distance from the participant to the crossing points located out of screen and on screen.     

使用KQ-1缓蚀阻焦剂,减轻糠醛装置腐蚀和结焦

独山子炼油厂糠醛精制装置设备腐蚀状况严重 ,尤其是加工高酸值原料 ,更加剧了设备的腐蚀。通过对腐蚀原因分析 ,决定从工艺防腐上解决 ,提出了加入缓蚀剂减缓设备腐蚀的方法 ,在实验室评价和工业装置中 ,评选了四种糠醛精制装置的缓蚀剂 ,其中KQ 1作为装置缓蚀剂效果最佳 ,平均缓蚀率达到 4 4 .5 % ,并估算了KQ 1工业使用的经济效果     

Manipulating the microstructure and rheology in polymer‐organoclay composites

A series of nanocomposites prepared by melt‐blending of cloisite‐based organoclays with poly(ethylene‐vinylacetate) (EVA) and neutralized poly (ethylene‐methacrylic acid) (EMA) copolymers were investigated via DSC, small‐angle X‐ray scattering (SAXS), and rheological techniques. SAXS results indicated partial clay exfoliation in all samples. In both EMA and EVA systems, the nominal melting temperature T_m and bulk crystallinity are not significantly affected by the presence of organoclays, suggesting that clay particles are predominantly confined in the amorphous phase. In rheological measurements (above T_m), the EVA‐clay system demonstrated a solid‐like rheological behavior under the small‐strain oscillatory shear, yet it was able to yield and flow under a steady shear, which is the characteristic of physical crosslinking. In contrast, the EMA‐clay system exhibited a melt‐like rheological behavior, where the influence of organoclay on the thermorheological behavior of the EMA composite was quite minimal. We propose that the carbonyl groups of vinylacetate in EVA interact with the clay surface, resulting in a strong physically crosslinking like interaction in the melt. On the other hand, the interaction between EMA and clay is weak because of repulsion between carboxyl anions and negatively charged clay surface.     

影响株洲火车站广场空气质量的因素研究

为了探究影响火车站广场污染物(总悬浮颗粒物和可吸入颗粒物)质量浓度的因素,以株洲火车站广场为研究对象,对总悬浮颗粒物和可吸入颗粒物质量浓度与人流密度、车流量的变化关系进行了试验性研究。结果表明,总悬浮颗粒物质量浓度与人流密度、车流量都呈正相关,其主要影响因素是车流量;可吸入颗粒物质量浓度与人流密度呈正相关,与车流量不呈明显的正相关,其主要影响因素是人流密度。细菌和病毒以可吸入颗粒物为载体被人体吸入而致病,因此人们活动时应尽量避开广场人流密度大的地方。     

轴向开槽对改善超磁致伸缩材料线性度影响的研究

磁致伸缩应变与磁场关系的非线性,影响了磁致伸缩控制元件的精度和稳定性。文章针对这一问题,在超磁致伸缩式微小型高速开关阀驱动部件设计基础上,提出了沿超磁致伸缩棒(GMM)轴向开槽的方法来改善GMM部件的工作性能。通过对轴向开槽前后GMM棒内部磁场强度和焦耳热分布的数值计算,分析了轴向开槽对改善磁场强度的分布和减少热损耗功率的影响,通过对GMM棒开槽前后伸缩量的测试,验证了开槽可以明显改善超磁致伸缩材料组件的非线性。     

Thermogravimetric analysis of methyl methacrylate‐graft‐natural rubber

The thermal degradations of methyl methacrylate‐graft‐natural rubber (MG) at different heating rates (B) in nitrogen were studied by thermogravimetric analysis. The results indicate that the thermal degradation of MG in nitrogen is a one‐step reaction. The degradation temperatures increase along with the increment of heating rates. The temperature of initial degradation (T₀) is 0.448B + 362.4°C, the temperature at maximum degradation rate, that is, the peak temperature on a differential thermogravimetric curve (T_p) is 0.545B + 380.7°C, and the temperature of final degradation (T_f) is 0.476B + 409.4°C. The degradation rate at T_p is not affected by B, and its average value is 48.9%; the degradation rate at T_f is not affected by B either, and its average value is 99.3%. The reaction order (n) is 2.1 and is not affected by B. The reaction activation energy (E) and the frequency factor (A) increase along with B, and the apparent reaction activation energy (E₀) is 254.6 kJ/mol. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2952–2955, 2002