溴化锂吸收式制冷机发生器放热系数的数学模型研究

本文根据现有文献中的实验数据，应用数值计算方法中的曲线拟合的最一乘法，建立了溴化锂吸收式制冷机发生器放热系数的数学模型，使离散数据连续化，为溴化锂吸收式制冷机组的计算机控制打下了基础。此外，本文首次定量地揭示了水在溴化锂溶液中的含量对放热系数的影响。     

Algorithm of heating temperature for Chongqing＇s winter greenhouses

Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient （WEC） and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production.     

随机利率因素下的多险种破产模型

推广了经典的复合泊松风险模型,建立了复合广义齐次poisson过程的多险种破产模型,并且考虑了随机利率因素,使得该模型更加具有实际意义．同时导出了随机利率下初始资本为u的破产概率(?)(u)的精确表达式,建立了调节系数方程,估计了调节系数的上下界．     

常系数齐次线性方程组dx／dt=AX的另一种解法

本利用哈密顿——凯莱定理和矩阵指数函数定义，给出一种较为简单又十分可行的求常系数齐次线性方程组的基解矩阵的方法，从而使该方程组可解．     

正态分布相关系数的二次经验Bayes估计

给出了两个一维正态随机变量相关系数的二次经经Bayes估计,并在一定条件下给出了渐近最优性的收敛速度。     

小康社会的经济学解读

“小康”是用以衡量国民生活水平状况时使用的一个概念，属于经济的范畴。一国国民生活水平从低到高依次可分为贫困、温饱、小康、富裕四个阶段。目前我国人民生活总体上达到了小康水平，但从“总体小康”到十六大提出的“全面小康”还有较大差距。     

手机话费分析模型

本文将手机费用简化为月租费、本地话费、漫游话费、长途话费 4项基本费用 ,经过综合分析 ,确定出不同的消费群体 .并对不同类型的收费模式 ,计算出在相同需求用户需支付的最低费用 .     

有理真分式的简易分解法

有理真分式简易分解的基本方法是等式两边同乘以适当因式，再取极限，求出待定系数。     

Proposing a framework to assess Internet usage in university education: an empirical investigation from a student's perspective

University administrators are continuously investing in Information Technology (IT) to support learning and help deal with educational budget cuts. Instructors are increasingly making their teaching materials available on the Internet. While administrators and instructors would like to make the Internet an effective educational tool, they need to understand what their students’ attitudes towards using it are. Since the use of the Internet in university education is still in its early stages, many issues regarding its use have not been fully addressed. This study was conducted to provide a better understanding of how the Internet is used in university learning from a student's perspective. Our research framework is based on the Theory of Reasoned Action, Technology Acceptance Model, and IT Diffusion Process Model. We use a survey conducted among university students to explore these issues. Research findings provide some useful insights for university administrators and educators.     

利用SPSS软件分析变量间的相关性

通过描述相关分析的研究意义、概念、分类以及利用SPSS软件进行变量间相关性分析的举例,说明了利用SPSS软件分析变量间的相关性,可以使我们了解事物之间的密切程度,并给事物之间的关系做出定性的分析。