巧用向量证题

相等问题、线性关系、正交分解关系、坐标、数量积、向量积求面积、混合积求体积和证三元分式不等式等问题利用向量来证题，能达到简洁、迅速之效。     

Indoor Particle Contamination in Airlaid Papermaking Workshop

An onsite testing based on eight-site air sampling was carried out in an airlaid papermak-ing workshop in Tianjin, China. By theoretical calculation, super absorbent polymer (SAP) size and its existent state in indoor static airflow were obtained. SAP content in the sampled air was tested through chemical analysis method and found to be 3.0-7.2 times that of the human health limit in production areas. The concentrations of total suspending particles (TSP) and respirable particles were achieved by weighing. Particles of the most concern differ for varied function areas. Particles smaller than 10μm are mostly produced in the main production process, and 73%-90% particles generated in packing areas are larger than 10μm. SAP raw material particles can easily changed to suspending form by inevitable extrusion and frication. Correlation between respirable particles and TSP agrees well with that in atmospheric environment.     

虚拟仪器自动测试系统软件设计

章提出了自动测试系统软件结构，即模块化和层次化结构的软件设计思想．在Windows平台下利用编程语言设计与设备无关的仪器模块向用户开放，提高了虚拟仪器的可互换性．最后给出了在可视化语言LabVIEW平台上虚拟仪器软件的设计示例。     

发展中国家的利率、储蓄与投资:一种理论综合与政策框架--对麦金农-肖两假说的再探讨

运用三阶段生命周期消费理论构造的储蓄－投资行为的微观模型，可以分析存款在财富积累过程不同阶段中的不同作用，表明利率政策通过既影响内源融资投资的收益又影响外源融资的可能性从而影响资本形成。基于微观模型的储蓄－投产行为的宏观模型，可以阐释利率对总储蓄、总投资及货币需求的作用机制。基于跨时期理论的分析框架，说明了麦金农－肖两假说间的相容性，强调了利率作用于投资储蓄及手续资产等决定时的时滞性。上述理论对我国如何确定总投资、总储蓄及货币需求，提供有益的借鉴。     

氨氮测定中水样预处理方法的改进

应用纳氏试剂比色法测定水样中的氨氮时，在水样预处理方面进行了改进．经实验证明，改进后的两种预处理方法能够降低全程序空白实验值，精密度较好，值得推广．     

电液伺服材料试验机的动力学响应特性研究

对MTS810电液伺服材料试验机在位移控制和载荷控制两种控制方式下的动力学响应特性进行了研究。以岩石压缩测试数据为例,对载荷-时间曲线、位移-时间曲线进行了对比分析,发现岩石破坏过程中,位移控制方式下可以观察到岩石的局部损伤至破坏的演化过程,载荷在岩石破坏时刻突然降为0;而载荷控制方式下看不到损伤演化过程,载荷未突然降为0。说明试验机本身的结构响应会影响对试样力学性能的测试。     

The Potential Impacts of Upcoming High-Stakes Testing on the Teaching of Science in Elementary Classrooms

In 1983, the National Commission on Excellence in Education in the United States issued a report called A Nation at Risk: The Imperative for Educational Reform. This report and other policy initiatives such as the No Child Left Behind Legislation recommended that the individual states institute assessments to hold schools accountable. This research explored the potential impact of impending standardised testing on teaching science in elementary schools in one school district in Florida. We explored the teachers' concerns about the upcoming high-stakes tests in science, possible impact on their curriculum and what changes, if any, will be made in the approach to science teaching and learning in their classrooms. As the teachers look toward the implementation of high-stakes testing in science, they have recognised the need to teach science. This recognition is not borne out of the importance of science learning for elementary school children, but rather out of fear of failure and the effects of tangible rewards or punishments that accompany high-stakes testing. In anticipation, the teachers are preparing to align their teaching to the science standards while aggressively searching for test preparatory materials. Schools are also involved in professional development and structural changes to facilitate teaching of science.     

Statistical Power in Evaluations That Investigate Effects on Multiple Outcomes: A Guide for Researchers

Researchers are often interested in testing the effectiveness of an intervention on multiple outcomes, for multiple subgroups, at multiple points in time, or across multiple treatment groups. The resulting multiplicity of statistical hypothesis tests can lead to spurious findings of effects. Multiple testing procedures (MTPs) are statistical procedures that counteract this problem by adjusting p values for effect estimates upward. Although MTPs are increasingly used in impact evaluations in education and other areas, an important consequence of their use is a change in statistical power that can be substantial. Unfortunately, researchers frequently ignore the power implications of MTPs when designing studies. Consequently, in some cases, sample sizes may be too small, and studies may be underpowered to detect effects as small as a desired size. In other cases, sample sizes may be larger than needed, or studies may be powered to detect smaller effects than anticipated. This paper presents methods for estimating statistical power for multiple definitions of statistical power and presents empirical findings on how power is affected by the use of MTPs.     

基于OBE理念的机械工程测试技术综合实验改革探索

"机械工程测试技术"是一门对实践性要求非常高的专业基础课程,而当前测试技术实验教学中存在诸多问题。该文针对该课程,基于OBE教学模式的理念,在基础实验训练的基础上,增设综合性自主设计实验,从仪器设备、实验过程、结果评价等方面进行系统的教学模式改革。改革结果表明,基于OBE教育理念的教学改革,不仅弥补了传统测试技术实验教学的弊端,而且满足了我院机械工程和相关专业本科生的教学需要。