高职院校电子类专业纸质教材建设探讨

针对加强高职院校纸质教材建设的意义,尝试着分析了目前高职院电子类专业纸质教材建设中存在的问题,并就如何加强高职院校电子类专业纸质教材建设,进行了探讨.     

A theoretical model for mid-and low-latitude ionospheric electric fields in realistic geomagnetic fields

The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at mid- and low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model, and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.     

影响工业企业可比产品成本降低额的因素分析模型

企业在进行可比产品成本降低分析中采用的初等数字运算工具对产品结构变化的影响分析概念模糊,没有定量分析。对此,本文把各影响因素以向量形式作为自变量,建立涵数,借助向量运算解决这问题,收到满意效果。     

含氢化合物酸性的强强判断

从能量角度分析氢化物与含氧酸的酸性强弱及其判断方法。     

电子公文传输系统研究及实现

众所周知,红头文件是我国各级政府机关实现上情下达、下情上达的重要途径,红色印章则是部门身份的认证。随着电子政务逐步深入展开,很多政府部门内部实现了无纸化办公,日常文件的起草、审批、流转多已通