二阶非齐次线性微分方程的求解

利用待定系数法导出一类二阶非齐次线性微分方程的特解公式,简化了求解过程。     

“微分方程的通解”探析

剖析了“微分方程的通解”的定义,并商榷了一些教科书（教参）中解微分方程的方法,分析解微分方程时常出现的一些错误：失根;随意去掉绝对值的符号、随意将三角函数改写成反三角函数或把反三角函数改写成三角函数形式而改变函数定义域。     

一类多滞量微分方程非负周期解的存在性

利用Leray—Schauder不动点定理，研究了一类多滞量微分方程非负周期解的存在性，得到了一些新的结果并改进了相应的结论．     

Differential Response family assessments: Listening to what parents say about service helpfulness

An increasing number of Child Protective Services (CPS) systems are implementing Differential Response (DR) approaches in which lower-risk families are served through a family assessment response that emphasizes a family centered approach and the provision of concrete and preventative services. Quantitative survey data collected from parents suggests that those who receive family assessments are more engaged, receive more concrete services, and have higher overall satisfaction than those who receive a traditional investigation; yet little is known about which services provided through a family assessment are most helpful to parents. This qualitative study sought input from 20 parents who received a DR family assessment response in order to provide an in-depth analysis of which aspects of their CPS experience they perceived as most helpful. Results suggest that a positive and emotionally supportive relationship with the caseworker was of utmost significance. Other caseworker-provided services were described as helpful, particularly those that helped parents establish or improve relationships with others, including advocacy with other service providers, mediation of family disagreements, and coaching on parenting or relationship skills. Material support, such as providing cash assistance for rent or furniture, was helpful when received but occurred less frequently and was sometimes a source of frustration when accompanied by lengthy waits for assistance. These findings have implications for CPS practice, including enhancing caseworkers’ relationship-building and engagement skills through pre-service educational coursework and in-service trainings; allowing caseworkers adequate time to develop supportive relationships with parents; and reducing the institutional barriers that delay the provision of concrete support.     

线性非自治时滞微分方程解的振动性

本文讨论了线性非自治时滞微分方程 x′(t)+sum from i=1 to n p_i(t)x(t-τ_i(t))=0的解的振动性,给出所有解振动的充分条件,改进了文[1,2]的结果.     

关于微分中值定理"中值点"的个数问题

在微分中值定理“中值点”存在的基础上,进一步研究微分中值定理“中值点”的个数问题.     

不等式证明的方法探索

不等式证明的途径与方法很多,每种方法都具有一定的特点和适用性,通过典型题例,分析并总结了应用高等数学理论证明不等式的方法及其适应条件。     

微小位移检测仪表的设计开发

目前,国内常用的差动变压器式传感器测微仪有指针式和数字式两种,但是存在诸如高精度测量范围小、零位调节不方便、功能单一和通用性差等问题．本文介绍了一种以89C51单片机为核心,采用现有的差动变压器式传感器测头的多功能、智能化测微仪．它具有高精度、智能化、多功能化、操作方便、性能稳定等特点．     

一类常微分方程解的存在性证明

我们考虑如下常微分方程解的存在性问题：dxdt=f（x,x（t））（1,1）x（0）=ξ（1,2）在文章中,一定的假设条件下,分别应用shauder不动点定理与Banach不动点定理,证明它的解的存在性,这说明对于微分方程若假设条件不同所采取方法也不一样。     

Exploring gender gap and school differential effects in mathematics in Chilean primary schools

ABSTRACT

Despite the systematic recognition of large gender gaps in favour of boys in mathematics performance in Chile, the role of schools in explaining this gap has been comparatively underresearched. This paper analyses a longitudinal dataset to explore within- and between-school variation of Chilean primary schools in promoting attainment and progress of girls and boys. In order to reflect the hierarchical nature of the educational data, multilevel modelling is used, with 163,044 students, nested within 3,355 schools, within 310 municipalities to fit raw, contextualised attainment, and value-added models. The weak evidence indicative of gender differential school effect in progress in Chilean primary schools was interpreted as non-substantive. However, differences in effectiveness played a significant role, as girls progressed more than boys in less effective schools, but the opposite was true in more effective schools. Finally, the study concludes that the Chilean gender gap needs to be addressed mainly beyond schools.