碱胁迫对叶片延迟发光的实验研究

选用绿宝石喜林芧叶片为材料,用BPCL型微弱发光测量仪测量了叶片经高浓度NaOH溶液处理后的延迟发光情况。结果发现:同一个叶片随着处理时间的延长,其延迟发光最初值和最后100s的光子数都先有一个小幅度的上升,然后又迅速下降;不同的叶片在相同的处理时间下,随着NaOH质量分数的增加,延迟发光最初值和最后100s的光子数都呈现上升的趋势,NaOH质量分数越大,上升得越快,随着处理时间的延长,上升的趋势变得越来越缓,最后各曲线越来越接近,且趋于平稳。整个实验表明,延迟发光可以规律性地反应碱胁迫对叶片的伤害程度,这为生物物理方法测量外界胁迫对叶片的影响提供了参考。     

氢原子光谱同位素谱线位移实验的参数优化

讨论了氢原子光谱实验中狭缝宽度、采集次数和负高压对氢原子光谱同位素位移谱线的影响,优化了氢原子光谱同位素位移实验的工作参数,获得了清晰的氢原子同位素位移光谱。通过该实验让学生掌握实验中多参数优化的方法,有利于加深学生对光谱理论的理解,有利于提高学生分析问题解决问题的能力。     

Interventions supporting baccalaureate achievement of Latinx STEM students matriculating at 2-year institutions: A systematic review

Numerous national reports have identified the importance of significantly improving pathways that begin with Latinx students enrolling in 2-year institutions and ultimately completing baccalaureate degrees in STEM fields at 4-year institutions. Many programs using multiple interventions have been designed, implemented, and studied to achieve this goal. To synthesize what has been learned from studies of these programs, this article presents a systematic review of published studies of programs designed to support Latinx student success in 2-year institutions and successful transfer to 4-year institutions, particularly for STEM majors. A total of 49 quantitative, 9 qualitative, and 16 mixed-methods studies published as reports, articles, or dissertations since 1980 were identified that met the criteria for the review. Studies covered a wide range of interventions, including mentoring, counseling, advising, study groups, tutoring, scholarships, orientations, career services, undergraduate research, articulation agreements, and transfer programs. Individually, these studies report positive influences on student success outcomes, including 2- and 4-year graduation, transfer to a 4-year institution, retention, and success in individual courses. However, the number of qualifying studies was surprisingly small, considering the importance of improving success of Latinx students and the length of time during which the problem has been repeatedly emphasized. Few interventions have been undertaken from explicitly assets-based perspectives or theoretical frameworks. The lack of explicit frameworks underlying interventions—combined with a sole/primary focus on students—suggests many interventions were approached from a deficit-based perspective. Further, the study found no pattern of replication studies that might confirm effectiveness of potentially promising interventions. Based on our analysis of evaluations presented in the studies, it does not appear that the research community has developed agreed-upon methods to evaluate commonly agreed-upon outcomes. Finally, no intervention has been sufficiently supported that widespread implementation could be recommended.     

数字集成电路参数测试仪的设计

针对现有集成电路测试设备结构复杂,功能单一的缺点,本文利用FPGA核心板、D／A模块、A／D模块、电流转换电压电路等器件,采用SOPC技术,设计了一个中小规模通用数字集成电路测试系统,在逻辑功能测试的基础上。实现了74系列中小规模数字集成电路直流性能参数的测试。通过实验,将测试结果与标准的反相器参数进行比较,数据结果一致。表明参数测试仪符合设计要求,设计方案具有一定的参考价值。     

二项分布中p~2的矩估计与极大似然估计

基于二项分布B(n,p)总体,给出了未知参数p2的矩估计和极大似然估计,并讨论了估计量的无偏性。     

生成性体育课程目标的若干问题研究

生成性体育课程是基础教育体育课程改革过程中逐渐形成的一种新的体育课程模式。其目标的选择必须符合生成性体育课程的要求,它的来源和筛选通过对学习者及校内外体育活动、专家的建议进行深入的研究得到。在设计生成性体育课程目标的过程中要遵循其基本要求和步骤,以充分发挥其在促进学生全面发展中的独特作用。     

某型空地导弹机动性分析

针对某型空地导弹机动性分析时气动参数的非线性特性,提出采用逐步逼近最终达到力矩平衡求解最大平衡攻角及可用法向过载的方法,解决了具有非线性气动特性导弹的可用法向过载计算问题,通过弹道仿真,对需用法向过载和可用法向过载进行了计算和对比．计算结果表明该导弹具有足够的机动能力,为总体设计和控制系统设计提供了依据．     

双线制高等教育制度建设与高等职业教育发展

职业教育与普通教育并行发展的双线制高等教育体系是符合高等教育大众化发展趋势的教育体系。目前国家对高等教育财政投入总量的不足,及高等教育内部的管理体制所导致的教育财政资源配置上偏向普通教育,双线制高等教育管理机构的不健全等,造成了高等职业教育和普通高等教育发展的失衡。因而,优化配置高等教育财政资源、合理规划教育体系内部结构对促进双线制高等教育发展有着重要的推进作用。     

“罪数论”之体系性结构及定位再思考

对罪数论的研究,我国传统的罪数论未注意到罪数论的两项不同的研究内容和研究层次。试图以同一原则来解决整个的罪数论问题,由此造成了理论研究和司法实践的困境。我们认为,＂罪数论＂的体系性结构应当是＂罪数—竞合论＂,或称之为＂广义竞合论＂,这一理论之下应当有两个分支：一是＂狭义的罪数论＂,解决对犯罪事实的认定问题;一是＂犯罪竞合论＂,解决对构成数罪的处罚问题。前者属于犯罪论范畴,后者属于刑罚论范畴。