Solution of the isochoric–isoenergetic flash problem by direct entropy maximization

A new algorithm to find the phase equilibrium conditions in systems with specified values of internal energy, volume, and number of moles of each component present (isochoric–isoenergetic flash problem) is proposed. The core of the procedure consists of maximizing the system entropy by iterating on the values, in each phase, of internal energy, volume, and number of moles of each component. Analytical expressions for the physical properties and derivatives required by the calculations were generated by computer algebra. The algorithm tests for the possible need to add or remove phases during the course of iterations. The paper discusses possible numerical difficulties during application of the procedure and how to overcome them. The algorithm has shown to be robust and capable of solving multiphase equilibrium problems, avoiding trivial solutions.     

Investigation of the Evolution Behavior of Light Tar During Bituminous Coal Pyrolysis in a Fluidized Bed Reactor

The evolution behavior of the light tar fraction of tar during large bituminous coal particle pyrolysis in a fluidized bed reactor at 500-900℃ was investigated to optimize the industrial process. The coal residence time was varied from 30 s to 150 s. The crude tar obtained was distilled and separated into the light fraction and the heavy fraction through an evaporator under conditions of 280℃ and 10⁴ Pa. The light tar was subjected to GC-MS analysis, and the 300 main species in each spectrum were determined and analyzed. The experimental results showed that the evolution behavior of the light tar fraction and the heavy tar fraction presented spectacularly different variation trends with pyrolysis temperature and coal residence time. The molecular weight and number of rings per aromatic compound molecule contained in the light tar fraction increased with increasing pyrolysis temperature because of polymerization. It was also observed that the amount of methyl substituents decreased with an increasing number of rings per molecule of poly-aromatic ring compounds. The chain aliphatic compound evolution was suppressed and underwent heterocyclization with increasing temperature.     

塞曼效应仿真实验平台

塞曼效应实验是学生了解原子具有磁矩和空间取向量子化现象的重要实验,至今塞曼效应仍是研究能级结构的重要方法之一.为了能够让学生更加清楚地了解塞曼效应实验的基本原理和操作规程,针对教学中的重点和难点,运用flash软件制作出塞曼效应仿真实验.该程序可全程高度仿真实验过程,具有界面友好、易于操作、无需安装等优点.为实验教学提供了一种新的辅助方式.     

强流脉冲相对论电子束加速器：—闪光二号

本文介绍了在西北核技术研究所建成的一台低阻抗脉冲电子束加速器——闪光二号。它主要用于核辐射效应模拟。加速器系统由Marx发生器、水介质同轴线和二极管三大主机部件以及十几个配套设备所组成。文中给出了在允电电压±55kV和±70kV两个电压等级下调试和运行的结果。最大输出电流600kA,管电压1.2MV。目前该加速器已用于电子束和X射线的实验研究。     

爆轰波面轮廓及其旋转对称性的同时观测

利用间隙技术并靠一个专用模板,就能仅通过一次试验而对爆轰波面轮廓进行记录,辽河对其不同对称程度和旋转对称性加以详细分析.     

‘Higher-order’ azomethine ylides in the synthesis of functionalized pyrroles and 5-oxo-5H-pyrrolizines

Azafulvenium methides generated by the thermal extrusion of SO₂ from 1-methyl- and 1,1-dimethyl-1H,3H-pyrrolo[1,2-c]thiazole-2,2-dioxides undergo [1,8]H sigmatropic shifts to give vinylpyrroles. Flash vacuum pyrolysis of the C-vinylpyrroles affords 5-oxo-5H-pyrrolizines or C-allyl-1H-pyrroles.     

气体流动热量计和苯、苯-环已烷气体热容的测量

A set of vapor-flow calorimeter has been constructed on the basis of Power's adiabatic calorimeter and Clarke s flash boiler. It can determine the heat capacities of mono-or multi-component vapors from vaporizing temperature to 600 K and 10—600 kPa pressures. For the calibration of the instrument, the heat capacities of benzene have been measured under 51.1, 101.3, 309.3 and 495.2 kPa and 370—600 K tempera-tures. For multicomponent vapor, benzene-cyclohexane has been determined. The results showed that the calorimeter has both the precision and accuracy better than 1.0% for either pure or mixtural vapors.     

Rapid and sensitive gas chromatographic method for detection of barbital and pentobarbital in blood using flash-heater methylation and nitrogen-specific detection

Summary A sensitive and simplified method is described for the determination of barbital (B) and pentobarbital (PB) in blood using gas chromatography with a nitrogen-specific flame ionization detector. After a simple one-step extraction, B and PB were reconstituted in trimethylanilinium hydroxide and introduced directly into the gas chromatograph. Lower limits of detection was 0.14 μg/ml for B and PB in either water or blood solutions. The recoveries for B from water and blood were 90 and 88%, respectively; for PB they were essentially complete. The average between-run and within-run coefficients of variation for B from water and blood were lower than 7.8%, whereas those of PB were lower than 3.0%. The scale and sensitivity of detection for B and PB were found to be suitable for use in pharmacokinetic studies in the rat.     

《高分子物理》课程多媒体课件的设计与制作

结合《高分子物理》课程的教学特点,运用多媒体制作软件Authorware 7.0和Powerpiont2000,Flash MX制作多媒体教学课件,取得了较理想的教学效果。     

闭杯闪点法测定氢化三丁基锡的闪点

使用MINIFLASH FLA全自动中温八杯闪点仪(闭杯闪点法)测定了氢化三丁基锡的闪点。探讨了诸多因素如样品的储存状态、点火次数、升温速率、大气压的校正、仪器保养方法等对闪点测定的影响。