乙醇和甲苯组成的最低共沸混合物热力学性质的研究

The molar heat capacity of the azeotropic mixture composed of ethanol and toluene was measured by a high precision adiabatic calorimeter from 80 to 320 K. The glass transition and phase transitions of the azeotropic mixture were determined based on the heat capacity measurements. A glass transition at 103.350 K was found. A solid-solid phase transition at 127.282 K, two solid-liquid phase transitions at 153.612 and 160.584 K were observed, which correspond to the transition of metastable crystal to stable crystal of ethanol and the melting of ethanol and toluene, respectively. The thermodynamic functions and the excess ones of the mixture relative to the standard temperature 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.     

石榴果汁饮品的研制与开发

石榴被称为药食兼用的果中之王，由于其特殊的性质，严重制约了它的深加工和规模化生产，为此，本文经过多次试验，在石榴果汁饮品加工方法及品质的保障等方面取得了较大的进展，使食用不便的石榴被加工成富有保健功效的特色果汁，具有许多产品无法比拟的独到特点。     

石榴汁饮料制作工艺的改进(一)--分光光度法测定石榴汁饮料的澄清度

对石榴汁加工工艺进行了论述。同时对用分光光度法测定石榴汁澄清度的可行性进行了研究，其结果是在波长为680nm时石榴汁透光率值可以作为其澄清度的参考依据．     

BEPC中的电子云不稳定性研究

多束团正电子储存环中可能发生电子云不稳定性(ECI). 自1996年起, 在北京正负电子对撞机(BEPC)上开展了与这种束流不稳定性相关的系列研究. 文章扼要介绍在BEPC上进行的电子云不稳定性研究, 包括实验观测和模拟计算, 并讨论可能的抑制措施.     

水与正丁醇二元体系最低共沸混合物的热容

Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water （x=0.716） plus n-butanol （x=0.284）] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. The functions of the heat capacity with respect to thermodynamic temperature were estabhshed for the azeotropic mixture. A glass transition was observed at （111.9±1.2） K. The phase transitions took place at （179.26±0.77） and （269.69±0.14） K corresponding to the solid-hquid phase transitions of n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. A thermodynamic function of excess molar heat capacity with respect to temperature was estabhshed, which took account of physical mixing, destructions of self-association and cross-association for n-butanol and water, respectively. The thermodynamic functions and the excess thermodynamic ones of the binary systems relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity and the calculated excess heat capacity with respect to temperature.     

Beam dynamics studies on BEPC-Ⅱ storage rings at the commissioning stage

During the 1 st and 2 nd stages of the commissioning of the upgrade project of the Beijing Electron Positron Collider (BEPCⅡ), which started on Nov. 12, 2006 and Oct. 24, 2007, respectively, we got the luminosity one tenth of its design value, provided beams to synchrotron radiation users for about 4 months, and studied beam dynamics as well. In this paper, some beam dynamics studies on the storage rings and their preliminary results are given.     

4,6-二甲氧基-2-嘧啶氨基甲酸甲酯的热力学研究

用精密自动绝热量热计测定了自行合成并提纯的4,6-二甲氧基-2-嘧啶氨基甲酸甲酯在80～380 K温区的摩尔热容.实验结果表明,在345～360 K温区,该化合物有一固-液熔化过程.经两次重复测定,得其熔化温度、摩尔熔化焓以及熔化熵分别为:(357.201±0.080) K, (26.289±0.029) kJ·mol^-1和(73.597±0.070) J·mol^-1·K^-1.通过分步熔化法得到该物质绝对纯样品的熔点为357.449 K.根据热力学关系和热容数据,计算出了该化合物相对于标准参考温度298.15 K的热力学函数.用DSC和TG热分析技术在300～500 K温区对该物质的热力学性质作了进一步研究,得到与绝热量热法一致的固-液熔化过程热力学参数,并得到该化合物蒸发过程的热力学参数:沸点为488.06 K,摩尔蒸发焓为81.73 kJ·mol^-1.     

婴幼儿营养方便食品的研制

本文初步探讨了婴幼儿的营养特点，并分析了的婴幼儿的摄食特点，在此基础上结合国外部分婴儿食品的设计思路，充分开发利用我区优质的肉、奶、水果、蔬菜资源，针对性地开发研制了4种符合婴幼儿生理需要，并易于消化吸收的婴幼儿断奶食品或辅助食品。