潜艇追踪问题研究

随着科学技术的发展和反潜作战能力的不断提高,如何做到迅速有效地进行潜艇追踪并将其击中是人们越来越关注的问题。本文针对潜艇追踪问题,首先,对其进行了深入分析并建立了微分方程模型;接着,提出了多种模型求解方法,重点介绍了解析法、欧拉方法和龙格-库塔公式法;然后,利用了MATLAB软件对各种求解方法进行了具体求解,并建立了优化模型来选择和确定最优的求解方法;最后,对潜艇追踪进行了动态模拟演示,使其更直观、生动地观察其运行状态。     

一类椭圆型变系数方程的差分格式

研究了一类二阶椭圆型变系数方程的初边值问题的求解方法,建立了一种差分格式,并且运用能量方法证明了这种格式的解的存在唯一性、收敛性和稳定性,所得结果是对相关文献中结果的一个补充。     

高速公路扩建路基沉降特性及其影响因素

结合某高速公路扩建工程,应用有限元方法建立了差异沉降的计算模型,分析了扩建路基的沉降特性,研究了路基高度、土基压缩模量、拓宽方式和宽度对路基差异沉降以及沉降曲线形态的影响.     

向量法诊断变压器微机差动保护的探讨

通过分析微机差动保护在变压器投运过程中经常出现差流的问题,运用向量法计算分析,提出了快速解决此类问题的办法,并进行了探讨.     

状态依赖时滞型微分方程正周期解的存在性

本文利用Krasnoselskii不动点定理,考虑了状态依赖时滞性微分方程x′(t) = −A(t, x(t))x(t) + B(x(t))F(x(t −  (t, x(t))))正周期解的存在性, 得到了该方程存在与不存在正周期解的充分条件.     

The solution of the Bagley-Torvik equation with the generalized Taylor collocation method

In this paper, the Bagley-Torvik equation, which has an important role in fractional calculus, is solved by generalizing the Taylor collocation method. The proposed method has a new algorithm for solving fractional differential equations. This new method has many advantages over variety of numerical approximations for solving fractional differential equations. To assess the effectiveness and preciseness of the method, results are compared with other numerical approaches. Since the Bagley-Torvik equation represents a general form of the fractional problems, its solution can give many ideas about the solution of similar problems in fractional differential equations.     

非线性二阶微分方程初值问题

本文利用上、下解方法讨论非线性二阶微分方程初值问题,给出了解的存在性的充分条件．     

基于差压法的水银式倾角传感器

为车载式喷雾机的喷杆水平控制提出了一种新的差压式倾角传感器,本传感器由差压式传感器、回形玻璃管和水银组成。其原理是用差压传感器将回形管两端水银柱差产生的压力差转换成电压信号,然后经A/D转换电路和微处理器换算成倾角。对本装置进行实际制作和实验标定,结果表明：本倾角传感器的分辨率为0.05o,准确度为0.1o。     

Differential effects of perceptions of equal,favourable and unfavourable autonomy support on educational and well-being outcomes

In this study, we examined whether high-school students experienced optimal educational and well-being outcomes when they perceived that they and their classmates received an equal, rather than unequal, and high amount of autonomy support from teachers. In a prospective study that aimed to predict academic grades and well-being outcomes, surface analyses of polynomial regression equations pointed that perceptions of equal autonomy support were the most optimal in terms of yielding highest levels of need satisfaction, autonomous forms of motivation and happiness with math courses. Additionally, in accordance with tenets of self-determination theory, we demonstrated that effects associated with perceptions of equal autonomy support were mediated by autonomous forms of motivation and psychological needs. Findings suggest that researchers and practitioners may be able to facilitate optimal educational and well-being outcomes by encouraging teachers to distribute autonomy support equally across students.     

Supporting resilience in war-affected children: How differential impact theory is useful in humanitarian practice

This paper examines the utility of the Differential Impact Theory for child protection practitioners who work in humanitarian settings, with a focus on war-affected children. A primary advantage of DIT is that it focuses efforts to strengthen children's resilience on improving children's social ecologies at different levels. This ecological focus is more likely to address the sources of children's suffering and resilience and also helps to avoid the problems associated with an individualized focus. It also shows how DIT provides a differentiated view of war-affected children and stimulates multiple interventions at different ecological levels, avoiding the common error of taking a one size fits all approach to intervention. In keeping with DIT, it suggests that child protection practice would benefit from addressing macro-level risks such as poverty and discrimination that are drivers of various harms to children and from more systematic linkages between macro- and micro-levels. It concludes that DIT serves as a critical lens for viewing current work on child protection in humanitarian settings and also for illuminating ways to develop more comprehensive supports for children's resilience.