提高大学生上课出勤率的工作方案探索

高校的学风建设对教育质量的提高有着重要作用,而大学生上课出勤率问题也越来越受到高校的关注.目前,大学生缺勤现象十分普遍,这一问题不仅影响了高校教学工作的正常开展与大学生专业知识水平的提高,而且对高校的声誉也造成不好的影响.因此,大学生的上课出勤率问题已成为高校教学与管理不能忽视的重要问题,对这一问题的研究越来越具有实际的意义.     

甘肃省玉门市赤金堡黑山北铂族元素地球化学特征

该矿化带是在进行1：20万区化扫面时发现。由于是首次对铂钯矿化体进行评价，通过对该矿化体的地球化学特征叙述，对该区成矿特征进行了初步总结，为该带寻找同类型矿床提供了具有参考意义的资料。同时，建议对该类矿床进行深入调查工作时，应重视铬、钴、镍、铜四元素及铂族元素除Pt、Pd外的其余元素的成矿可能性。     

Atomic-scale segregation behavior of Sn/Ti and O at Σ3[11¯0](111) grain boundary in niobium

First-principle calculation was performed to illustrate the atomic arrangement and segregation behavior of Sn/Ti and O in View the MathML source grain boundary, and the interaction of oxygen interstitials with Sn/Ti atoms on the grain boundary was studied. The analyses on the segregation energies and geometric positions, and the electron densities show that Sn, Ti and O atoms segregate at the Σ3 grain boundary. And the preferred segregation sites of the impurities at View the MathML source were determined. When Sn segregates at grain boundary plane, the O atom prefers to the bulk-like site and shows no segregation tendency at grain boundary, whereas the segregated Ti atom can slightly enhance oxygen segregation at the grain boundary.     

O2流量对O2/C4F8等离子体刻蚀SiCOH低k薄膜的影响

研究了O2/C4F8等离子体刻蚀SiCOH低k薄膜时O2流量对刻蚀率、表面结构的影响,及其放电等离子体特性的关联.发现O2流量的增大可以极大地提高多孔SiCOH薄膜的刻蚀速率,降低表面的粗糙度,减少SiCOH薄膜表面的C:F沉积.等离子体特性的光谱分析表明,O2的添加,增强了C与O之间的反应,从而在Si、F反应刻蚀Si的同时,C、O之间的反应使C消耗,实现Si、C的同步刻蚀,从而获得SiCOH低k薄膜的高刻蚀率和低粗糙度表面.     

建筑工程造价存在的问题及对策研究

建筑工程造价对于建筑的成本预算、质量起着非常重要的作用.它是建筑工程管理的关键环节,面对日益激烈的市场竞争,如何解决好当前工程造价存在的问题,已成为刻不容缓的课题.本文在相关理论分析的基础上,对我国当前工程造价进行具体分析,指出我国工程造价存在的问题,并结合我国实际情况,制定出符合我国战略发展的工程造价对策.     

Methods, Models and Information Technologies for Decision Support Systems

Special Issue

Methods, Models and Information Technologies for Decision Support Systems     

Optimal design and experiment research of an orthogonal-parallel six-axis force/torque sensor

A novel orthogonal-parallel six-axis force/torque sensor is studied based on a modified Stewart platform architecture,and the optimal design and experiment rese...     

Sm3+掺杂纳米晶ZrO2材料的制备及表征

用化学沉淀法制备纳米晶ZrO2∶Sm3 发光粉体,用X射线衍射谱对材料的粒径和晶体结构进行了表征,探讨了制备条件对样品粒径和晶体结构的影响.用荧光激发和发射光谱对材料的发光性质进行了表征,合理地归属了各谱项和跃迁.     

Introducing an External Terminal Operator or Not? The Decision of Ports in a Duopoly Market

Facing with increasing competition, many ports are taking innovative approaches to improve productivity and profits. Among a variety of methods, introducing external terminal operators(ETOs) while the port acts as a landlord to collect "rents" from those operators for conducting terminal activities inside the port is regarded as an effective way and is commonly observed in practices.This paper analyzes the decisions of two competing ports about whether to introduce their respective ETOs using a three-stage non-cooperative game model when there already exists a port's self-operation terminal operator(STO). At the first stage, the two ports simultaneously decide whether to introduce an ETO. If a port decided to introduce an ETO, at the second stage, it will further decide the unit fee to charge from the ETO. At the third stage, the two ports and the introduced ETO(s) simultaneously decide their respective profit-maximizing output levels. The findings indicate the equilibrium is both ports will introduce their respective ETOs, but when the ports and ETOs are substitutable in the sense of having the same level of productivity, the equilibrium solution is only one port should introduce an ETO. And simulation results show that even if one of ETOs is inefficient this still hold true.     

Forecasting stock volatility in the presence of extreme shocks: Short-term and long-term effects

This paper introduces a novel generalized autoregressive conditional heteroskedasticity–mixed data sampling–extreme shocks (GARCH-MIDAS-ES) model for stock volatility to examine whether the importance of extreme shocks changes in different time ranges. Based on different combinations of the short- and long-term effects caused by extreme events, we extend the standard GARCH-MIDAS model to characterize the different responses of the stock market for short- and long-term horizons, separately or in combination. The unique timespan of nearly 100 years of the Dow Jones Industrial Average (DJIA) daily returns allows us to understand the stock market volatility under extreme shocks from a historical perspective. The in-sample empirical results clearly show that the DJIA stock volatility is best fitted to the GARCH-MIDAS-SLES model by including the short- and long-term impacts of extreme shocks for all forecasting horizons. The out-of-sample results and robustness tests emphasize the significance of decomposing the effect of extreme shocks into short- and long-term effects to improve the accuracy of the DJIA volatility forecasts.