关于能、、的新模型——物系∪环境

分析了现有文献中寂态、(火用)及(火无)等概念。提出大系统(物系∪环境)模型。将‘寂态’重新解释为‘大系统寂态’;将大系统能量划分为‘最大可能输出能’E_M和‘不可输出能’E_N(不利用外界作功条件下);定义大系统(火用)E_X为E_M中可以转变部分,大系统(火无)为E_M中不可转变部分;E_N包括大系统可逆地过渡到寂态过程中两子系统直接互相传递的能E_i和大系统其余内能。这样,重新解释了能=(火用)+(火无)公式的意义,从而对现有文献中的一些有争议问题提出了作者的解决方法。最后推导了正压物系∪环境的E_M(物理能)E_X及A_n的表达式。     

关于“开系中热量和功表达式”的讨论

本文讨论了在开系和闭系中功和热量的本质以及它们和熵的关系。据此指出将闭系中热量和功的表达式简单地移植到开放系统中去是不恰当的。     

Study on the thermal decomposition kinetics of nano-sized calcium carbonate

This study of the thermal decomposition kinetics of various average diameter nano-particles of cal-cium carbonate by means of TG-DTA(thermogravimetry and differential thermal analysis) showed that the thermal decomposition kinetic mechanisms of the same crystal type of calcium carbonate samples do not vary with decreasing of their average diameters ; their pseudo-active energy Ea; and that the top-temperature of decom-position Tp decreases gently in the scope of micron-sized diameter, but decreases sharply when the average di-ameter decreases from micron region to nanometer region. The extraordinary properties of nano-particles were explored by comparing the varying regularity of the mechanisms and kinetic parameters of the solid-phase reac-tions as well as their structural characterization with the variation of average diameters of particles. These show that the aggregation, surface effect as well as internal aberrance and stress of the nano-particles are the main reason causing both Ea and Tp to decline sharply with the decrease of the average diameter of nano-particles.     

Effects of breakfast with different calorigenic amounts on blood glucose, insulin and glucagon levels

This study was aimed to investigate the relationship between breakfast and serum glucose, insulin and glucagon concentrations in order to establish a model breakfast appropriate for Chinese. Twenty-four volunteers were randomly assigned to four study groups: high carbohydrate breakfast, high fat and protein breakfast, the typical breakfast and fasting. Each subject had serum and urine samples collected while fasting and at 1,2 and 3.5 hours following the meal. The concentration of serum glucose, insulin and glucagon was measured. The levels of serum glucose in group A, B and C differed significantly at 1 and 2 hour after meal compared to those at fasting (P<0.05). The serum glucose in group A increased insignificantly after meal. The serum insulin levels were in group A, B and C significant different compared with control group(P<0.05).Those peaked at 1 hour after meal, with group C rising the furthest. Compared with the fasting group, the serum glucagons rose and maintained the increase after breakfast in group A, B and C (P<0.05). The data suggested that various diets with different calorigenic amounts increased hormone concentration to various extents. We found that a breakfast rich in carbohydrates could maintain proper blood glucose level.     

化工基础中的热量传递

动量传递、热量传递和质量传递在化学工程中通称为传递工程,在本质上都属于物理过程。传递工程和化学反应工程构成化学工程学科的基本内容。热量传递是化学工程的基本内容之一。 传热过程和其它传递过程一样,在一定的条件下存在一种极限,达此极限后就没有净的热量传递发生,即达到热平衡状态。热平衡关系很简单,即物系在各点温度相等。传热     

冲击热流快速加热半无限体热冲击问题非傅立叶效应研究

基于热量传播速度为有限值的双曲线型导热微分方程式,对实际中常见的冲击热流快速加热半无限体所产生的动态热应力问题进行了理论研究,分析了动态温度效应和热;中击期间动态热应力的变化规律。所得结果对完善发展热冲击理论及分析其机理都具有重要的意义。     

养好哺乳仔猪的关键措施

一、哺乳仔猪的生理特点 1.消化器官不发达.仔猪主要依靠母乳为营养源,缺乏胃蛋白酶、蔗糖酶,对进入胃肠道的细菌缺乏抵抗能力,所以哺乳仔猪易患疾病. 2.体温调节机能不发达.机体不能产生足够的热量,再加上体表面积大,皮薄、膘薄、毛稀,热量散失大,因此,哺乳仔猪特别怕冷.     

多相流动力学第2卷，热量和力的传递，第三版

多相流动广泛地存在于自然界和工业过程中。对这些过程的分析、控制和预测需要了解多相流动力学。本书是作者多相流动力学系列专著的第2卷。该专著共3卷，系统总结了多相流动力学的基本原理、数学模型和数值方法。第1卷详细推导了局部时间和空间平均的多相流体力学基本方程组和计算方法，对多孔介质体系的质量、     

(火用)物理意义的再认识

(火用)可以评价热力学系统的作功能力和能量的可用性,在能源科学及工程领域具有广泛的应用.通过回顾热量(火用)、机械(火用)与热力学能(火用)的物理概念,我们发现,目前对(火用)表达式的推导过程缺少对热力学过程实现方式和系统模型的具体分析,导致在理解(火用)的物理意义时误认为系统只与环境进行热、功相互作用.为了明确闭口系...