新源草原旅游业发展的理性思考

本以新源草原旅游业的发展，从坚持可持续发展战略，加强旅游产品的包装，客源市场的开发，基础设施建设及旅游企业的介入，从理性思考上进行了探讨。     

VSO教师英语口语教学透视与启迪

VSO教师英语口语教学有很多特点和很好的经验，但也存在一些不足，通过研究和借鉴外籍教师英语口语教学经验，将会给中国教师提供一条促进英语口语教学改革、提高英语口语教学质量的途径。     

开发具有E-Mail功能的VB应用程序

面对企业和单位对个性化电子信息传递的需要,探讨利用VB编程实现的一种方法.     

Calculating the power of alternative choices by school leaders for improving student achievement

This paper addresses a wicked problem faced by leaders wanting to be evidence informed in their choices of school improvement priorities and the most productive leadership practices to enact in pursuing those priorities. While local contexts will always be central to these choices, results of research ought to provide useful points of departure. But determining what relevant evidence recommends, local context aside, is far more difficult that the admonition to be ‘evidence informed’ seems to imply and the research community has offered few systematic solutions to the problem. This paper offers one possible solution, the calculation of ‘Power Indices’ using, for the purposes of illustration, evidence about the effects of a selected set of potential school improvement priorities (teachers’ emotions) on student learning, in combination with evidence about the effects on teacher emotions of a selected set of transformational leadership practices. Results argue for the value of a unique line of future research enabling school leaders to make choices about both school improvement priorities and how they might best pursue those priorities that systematically reflect the results of relevant evidence.     

论信息技术对政务的革新

信息技术越来越多地应用于社会各领域,政务处理当然也不例外。讨论了政务处理方法的历程,重点突出了新的信息技术对政务的革新作用。以检察院为例提出了具体应用数据仓库和数据挖掘技术的有效方法。     

女大学生如何增强自我防护意识

文章首先论述了提出这个论题的必要性，接着从了解掌握一定的科学的性知识、树立健康的符合时代进步的性观念、在恋爱交友中用理智调控感情等三个方面重点具体地论证了论题。     

Conversion of CO<Subscript>2</Subscript> to useful substances with composite iron,nickel, and copper catalysts

Composite materials of Fe/Al₂O₃, which consist of small particles of iron supported by thermally stable alumina even at 500–700 °C, have been widely used in the water-gas shift reaction for natural gas reforming. Therefore, Fe/Al₂O₃ is one of the promising candidates for re-transformation of exhausted CO₂ into fuels such as alcohols and hydrocarbons. The development of a CO₂ reforming system using the composite materials of Fe/Al₂O₃ through CO₂ reduction to CO, dissociation of water into hydrogen, and methanol synthesis has been investigated. It was found that dry and steam (i.e. wet) reforming of CO₂ produced almost the same amount of CO. At a temperature above 500 °C, maximal and saturated yields of CO and H₂ from CO₂ and water were obtained. However, this CO₂ reforming system requires higher-pressure conditions from several tens to hundreds standard atmospheric pressure in order to achieve high yield and selectivity for methanol production. In this study we developed the modified CO₂ reforming system by the utilization of Ni and/or Cu instead of Fe in order to obtain other types of useful products such as CO, CH₄, and carbon, more efficiently and selectively under atmospheric pressure. When Ni or Cu was used, conversion of CO₂ was reduced to 76%, while 9% of methane was detected in the case of Ni. On the other hand, though the CO₂ conversion reduced half of the Fe, the selectivity of CO from CO₂ increased to 95% in the case of Cu.     

Numerical investigation of cavitating flow behind the cone of a poppet valve in water hydraulic system

Computational Fluid Dynamics (CFD) simulations of cavitating flow through water hydraulic poppet valves were performed using advanced RNGk-epsilon turbulence model. The flow was turbulent, incompressible and unsteady, for Reynolds numbers greater than 43000. The working fluid was water, and the structure of the valve was simplified as a two dimensional axisymmetric geometrical model. Flow field visualization was numerically achieved. The effects of inlet velocity, outlet pressure, opening size as well as poppet angle on cavitation intensity in the poppet valve were numerically investigated. Experimental flow visualization was conducted to capture cavitation images near the orifice in the poppet valve with 30° poppet angle using high speed video camera. The binary cavitating flow field distribution obtained from digital processing of the original cavitation image showed a good agreement with the numerical result. Project supported by the National Natural Science Foundation of China (No. 59835160) and Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry of China (No. 50175097)