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高考在韩国历来都非常受重视,因而考试竞争十分激烈。近年来,韩国政府为了减缓高考竞争压力,采取了一系列改革措施,在政府承担国民教育责任、大学入学考试形式、招生录取方式等几方面进行了不少改革,以推动基础教育从应试教育向素质教育的转变,已取得明显实效。 相似文献
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In this paper,a new pressure reducing valve(PRV) with an orifice plate is proposed.The main objective is to explain the mechanisms of pressure reduction and energy conversion in the new PRV.A numerical simulation method was used to investigate the PRV internal flow field and to analyze the throttling effects of the orifice plate and the transform of thermal parameters as outlet pressure,outlet temperature,velocity,and superheat.A structure improvement method for the valve body and orifice plate is put forward to reduce energy loss.The governing equations for internal flow numerical simulation are composed of the continuity,momentum,energy and k-ε transport equations,based on isotropic eddy viscosity theory.Different valve plug displacement models were built to describe the double throttling process.Our analysis shows that the steam pressure drops twice and the degree of superheat increases.There are also lots of eddies which clog the flow channel and disturb the steam flow in the valve cavity after the valve plug and the outlet cavity.After modifying the structure,the numerical results show a better performance of steam flow. 相似文献
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频频爆发的上市公司财务丑闻与注册会计师职业道德和诚信的缺失密切相关。引发注册会计师职业道德滑坡诚信危机的主要原因在于市场竞争的压力,竞逐利润的动机和市场不完善提供的机会。 相似文献
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通过对主送轨机液压系统的工作原理分析，确定了保压不正常的原因，并对其改进，使液压系统能够达到保压、稳定、持续，解决电机系统长期负载运行问题。 相似文献
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与公办学校教师相比,民办学校教师面对着更多生存与发展的压力,保障体系不健全、竞争无序、人际关系紧张、职业倦怠、企业化管理体制缺乏对教师人性关怀、工作强度过大、身心疲惫等,这些问题都是民办学校教师的主要心理压力源,必须从学校和教师个人双方入手,才能有效地应付压力,帮助民办学校教师建立良好的心理健康状态。 相似文献
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Objective： To discuss possible relationships between class In malocclusion and perioral forces by measuring the pressure from the lips and the tongue of children with class nI malocclusion. Methods： Thirty-one children with class In malocclusion were investigated and their perioral forces were measured at rest and during swallowing under natural head position by a custom-made miniperioral force computer measuring system. Results： The resting pressures exerted on the labial side and palatine side of the upper lett incisor, as well as the labial side and lingual side of the lower lett incisor, were 0 g/cm^2, 0 g/cm^2, 0.57 g/cm^2 and 0.23 g/cm^2, respectively. Correspondingly, the swallowing forces were 2.87 g/cm^2, 5.97 g/cm^2, 4.09 g/cm^2 and 7.89 g/cm^2, respectively. No statistical difference between muscular pressure and gender existed. During swallowing, the lingual forces were significantly higher than the labial forces （P〈0.01）, however, at rest there was no significantly different force between these two sides. Compared to the normal occlusion patients, children with class Ⅲ malocclusion had lower pedoral forces. The upper labial resting forces （P〈0.01）, the lower labial resting forces （P〈0.05） and all the swallowing pressures from the lips and the tongue （P〈0.01） showed statistical differences between the two different occlusion conditions. Meanwhile, no significant difference was found for the resting pressure from the tongue between class Ⅲ malocclusion and normal occlusion. Conclusion： Patients with class Ⅲ malocclusion have lower perioral forces and this muscle hypofunction may be secondary to the spatial relations of the jaws. The findings support the spatial matrix hypothesis. 相似文献
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本文设计了一种智能变压路灯节电控制系统,通过单片机控制单元变压器抽头的切换以控制负载上输出电压,达到节电控制要求,通过此方案可以做到节电30%左右,同时为了提高系统的使用寿命,设计了过压或欠压故障报警等模块。 相似文献