豪也F-15A语言练习系统的管理与维护对策

语音室是外语教学的基础设施,是学生学习语言的理想环境.豪也 F-15A 型语言学习系统是基于以太网扩充技术开发,为专业听、说、读、写开发的新型语言学习系统.如何对其进行科学的管理与维护,使其充分发挥其功效是实验管理的重要环节.本文将从管理与维护中出现的问题进行探讨,并提出有效的解决对策.     

Incentives and effort in the public sector: Have US education reforms increased teachers’ work hours?

Beyond some contracted minimum, salaried workers’ hours are largely chosen at the worker's discretion and should respond to the strength of contract incentives. Accordingly, we consider the response of teacher hours to accountability and school choice laws introduced in US public schools over the past two decades. Total weekly hours of full-time teachers have risen steadily since 1983 by about an hour, and after-school instructional hours have increased 34 percent since 1987. Average hours and the rate of increase also vary widely across states. However, after accounting for a common time trend in hours, we find no association between the introduction of accountability legislation and the change in teacher hours. Education reforms are, however, associated with an increase in student test scores, presumably due to other types of changes in school and teacher behavior.     

黑色的人物画廊--《第二十二条军规》人物评析

美国当代作家约瑟夫.海勒的《第二十二条军规》一书是一幅以黑色为基调的人物画廊,描绘了众多栩栩如生的人物,作者通过对这些人物的多维及单维角度刻画,运用“黑色幽默”(Black Humor)的技巧,反映了战后美国真实的官僚社会的方方面面。作为“黑色幽默”文学的代表作,书中众多的形形色色的人物的言行举止都围绕着“第二十二条军规”这个圆心,这群各种怪癖的人物不停地窜动,上演了一幕幕荒诞、疯狂、混乱、无序、狂想型的人间闹剧。本文试从海勒式的黑色幽默的视角,去探索众多人物的内心世界,去理解作品的主题。     

The impact of merit-based financial aid on college enrollment: A field experiment

Merit-based financial aid awards have become increasingly prevalent in the pricing policies of higher education institutions. This study utilizes an experiment to estimate the efficacy of merit-aid awards in achieving the institutional objective of attracting the most academically desirable applicants. I find that merit aid has a statistically significant but inelastic effect on enrollment of extremely high ability students. Additionally, the setting of this paper allows for a test of whether students respond to the framing of price in making enrollment decisions (i.e. price illusion), holding net price constant. There is weak evidence in support of price illusion among this set of students.     

The determinants of school district salary incentives: An empirical analysis of,where and why

Most public school districts in the United States use a salary schedule to determine compensation for teachers within the district. However, some school districts have implemented incentive pay schemes that allow flexibility at the school or even individual teacher level. These compensation schemes in some ways may more closely approximate a competitive labor market. This study examines the factors that influence a district's decision to offer incentive pay using districts from the 1999 to 2000 Schools and Staffing Survey. The results suggest that school districts that face barriers to recruitment or retention and districts that face competition from non-sectarian private schools are more likely to offer incentive pay.     

Faculty employment and R&D expenditures at Research universities

This study uses panel data to examine the relationship between faculty employment and external R&D expenditures at Research and Doctoral institutions over a 15-year period of time. On average, a 1% increase in the number of full-time faculty is associated with about 0.2% increase in total R&D expenditure. Further, a one percentage point increase in the share of full-time faculty members that are not on tenure-track lines is associated with a decrease in total external R&D expenditure by about 0.6%, suggesting that full-time faculty that are tenured or on tenure-tracks are the main category of faculty that generate external R&D funding. Further, our results suggest that an increasing usage of part-time faculty, holding constant the institution's full-time faculty size, boosts an institution's external R&D expenditures. On average, a one percentage point increase in the share of part-time faculty members is associated with a 0.44% increase in the total external R&D expenditures. Increases in graduate student enrollments are associated with increases in external R&D expenditures. Finally, an institution's external R&D expenditures are significantly influenced by both the amount of its own institutionally financed research expenditures and the level of federal funding for research.     

ISSR markers based on GA and AG repeats reveal genetic relationship among rice varieties tolerant to drought, flood, or salinity

Drought,flood,salinity,or a combination of these limits rice production.Several rice varieties are well known for their tolerance to specific abiotic stresses.We determined genetic relationship among 12 rice varieties including 9 tolerant to drought,flood,or salinity using inter-simple sequence repeat (ISSR) markers.Based on all markers,the nine tolerant varieties formed one cluster distinct from the cluster of three control varieties.The salt-tolerant varieties were closest to two flood-tolerant varieties,and together they were distinct from the drought-tolerant varieties.(GA)8 YG was the most informative primer,showing the highest polymorphic information content (PIC) and resolving power (Rp).The drought-,flood-,and salt-tolerant varieties grouped in three distinct clusters within the group of tolerant varieties,when (GA)8 YG was used.Sabita was the only exception.The two aus varieties,Nagina22 and FR13A,were separated and grouped with the drought-and flood-tolerant varieties,respectively,but they were together in dendrograms based on other primers.The results show that ISSR markers associated with (GA)8 YG delineated the three groups of stress-tolerant varieties from each other and can be used to identify genes/new alleles associated with the three abiotic stresses in rice germplasm.     

《花腔》的历史反思与叙事艺术——兼与《第二十二条军规》比较

《花腔》中的"爱"和《第二十二条军规》中的"军规"都是人性中的自私与邪恶的象征,它们滥用权力制造历史圈套,对生命的尊严和价值进行扭曲和湮灭。《花腔》和《第二十二条军规》从不同的叙述角度表现了冷酷中的黑色幽默,以戏仿讽刺不合理的现象。《花腔》和《第二十二条军规》采用回旋式的叙述方式,穿插众多人物传记,展示了社会各个层面上的关系。《花腔》与《第二十二条军规》的这些相似性,在一定程度上体现了李洱和约瑟夫·海勒的"经验同化"。     

F^-在有机合成反应中的应用

综述了氟离子作为电子供给体和非亲核性的催化剂在烷基化反应、羟醛缩合反应、Michael加成、Knoevenagel缩合反应、Wittig反应和Wittig-Horner反应、重氮化反应等有机反应中应用，并对其催化机理进行了探讨。     

Who benefits from student aid? The economic incidence of tax-based federal student aid

Federal benefit programs, including federal student aid, are designed to aid targeted populations. Behavioral responses to these programs may alter the incidence of their benefits, a possibility that receives less attention in the literature compared to tax incidence. I demonstrate the importance of benefit incidence analysis by showing that the intended cost reductions of tax-based federal student aid are substantially offset by institutional price increases for a sample of 4-year colleges and universities. Contrary to the goal of policymakers, I find that tax-based aid crowds out institutional aid roughly dollar-for-dollar. Unfortunately, it is not clear how institutions utilize these captured resources, so that the ultimate incidence of the programs is uncertain.