Measuring Determinants of Student Return VS. Dropout/Stopout VS. Transfer: A First-to-Second Year Analysis of New Freshmen

To reflect academic challenges and enrollment patterns of today’s freshmen, this study measures the impact of high school preparation, first-year academic performance, multi-institution enrollment, and financial aid support on second-year persistence. Using multi-year cohorts at a public research university, results confirm the importance of including first-year math experience, math intensity of the declared major, simultaneous enrollment at another college/university, and second-year financial aid offers when measuring freshmen retention. The positive impact of a large-scale, state-funded scholarship program in widening access to college must be balanced against findings that show academic performance and readiness to take on and pass first-year math to be more important than aid in explaining freshmen dropout and transfer-out during both first and second semesters. Middle-income students with greater levels of unmet need face an elevated departure risk, while academically well-prepared freshmen with unmet need are more likely to transfer to other institutions.     

常温下扑热息痛的常规、半常量及微型制备方法初探

本文介绍了在常温下扑热息痛常规、半常量及微型化制备方法的实验比较,即以对氨基苯酚为原料,以二氯甲烷为反应溶剂,在常温下进行常规、半常量及微型化三种方法合成了扑热息痛。实验结果表明,微型法优于常规法和半常量法。常温下微型化合成扑热息痛条件温和,达到反应终点时间仅为15分钟,收率为96.03%,有效地提高了实验效率。     

微波辐射加热制备半导体ZnS纳米粒子

在甲醛溶液中，以Zn(Ac)2和TAA为源材料，通过微波辐射加热合成了ZnS半导体纳米粒子，并用XRD、TEM、紫外反射光谱进行了表征。     

新型水处理剂高铁酸钾的湿法合成及应用

高铁酸钾是一种新型高效的多功能水处理剂,具有氧化、吸附、絮凝、杀菌等功能,本文概述了目前有关高铁酸钾的湿法合成机理,工艺条件及主要应用领域的研究状况,对进一步改进高铁酸钾的湿法合成技术具有一定的指导意义.     

Addressing diversity in US teacher preparation programs: A survey of elementary and secondary programs’ priorities and challenges from across the United States of America

Data gathered from 142 public university elementary and secondary teacher preparation programs across the United States (representing the preparation of approximately 23,000–30,000 new teachers annually), indicated that race/ethnicity was the most emphasized diversity topic followed by special needs, language diversity, economic (social class), gender, and sexual orientation. The majority of programs addressed diversity topics across program classes. States were similar in the priority assigned to various diversity topics, with the exception of California, which placed greater emphasis upon language diversity but less upon special needs as compared to other states. In addition, there appeared to be little to no relationship between the faculty demographics (gender and race) and the priorities placed upon gender and racial diversity in programs. The project also surveyed program coordinators’ assessments of the various challenges to the inclusion of diversity topics. Finally, the data suggested that possible relationships might exist between faculty attitudes/knowledge regarding diversity topics and student attitudes.     

空洞探测模型

对 2 0 0 0年网易杯全国大学生数学建模竞赛D题 ,即对山体、隧洞、坝体等内部结构探测问题 ,使用对数据进行误差分析的方法来确定其内部空洞的位置     

皖西白鹅呼吸器官的解剖观察

本试验研究了皖西白鹅呼吸器官的形态特征.试验选用成年皖西白鹅20只,通过颈动脉放血致死后,用10%福尔马林溶液固定.采用肉眼和显微镜观察皖西白鹅呼吸器官的形态位置与结构特征.结果表明成年皖西白鹅的呼吸器官由鼻腔、喉、气管、鸣管、支气管、气囊和肺等组成.     

CaSnO3的软化学制备与表征

采用软化学法制备了前驱体CaSn(OH)6,经不同温度下热处理得到了锡酸钙粉末,并用TG-DTG、XRDI、R、SEM等对其进行了表征。结果表明,用该法合成的锡酸钙具有正交晶格结构,粒度分布均匀,该方法具有操作简单、环境友好等优点。     

基于Fluent的离心分离腔体内流场模拟仿真

为研究离心式分离腔体内部气流流动轨迹以及梗丝颗粒的运动规律,进一步深入研究梗丝分离效果,基于ANSYS建立流体域模型,利用流体仿真软件Fluent,采用RNG湍流模型模拟腔体内气流轨迹,拉格朗日离散相模型（DPM）模拟颗粒相运动规律,得到腔体内气流轨迹、压力和颗粒相运动轨迹云图,并在入口处设定不同大小的气流速度,当入射速度为6m/s时,气流流动轨迹发生改变,达到8m/s时气流轨迹比较理想,且颗粒运动轨迹正确。此时梗丝在离心分离腔体内可以得到有效分离,梗中含丝率降低到2.55%左右,烟丝利用率进一步提高。     

"短期投资跌价准备"的核算原则特色和实务

“短期投资跌价准备”科目的增设体现了小企业会计核算原则的特色,使得会计要素确认、计量方面更务实和更贴切地表达了会计修订性惯例的要求。在帐务处理上,从新旧帐目的衔接过渡、运用成本与市价孰低法计提跌价准备采用三种方法处理会计实务、到处置短期投资时,如何结转已计提的短期投资跌价准备等方面凸显出新制度的精要。