动力定位推力系统研究

阐述了动力定位推力系统的几种常见形式,分别针对每种推力器进行介绍和分析。动力定位的推力系统不同于传统的船舶推力系统,它并不要求能提供较快的速度,但能提供较大的推力,并且对灵活性和冗余度也有较高要求。同时,作为动力定位系统的执行机构,推力系统的优劣对整个动力定位能力有着重要的影响。在总结前人在动力定位推力系统方面研究的基础上,从可应用于动力定位的推力系统分类、设计要求、水动力干扰问题3个方面进行分析和总结,提出设计动力定位推力系统的方法和减少推力系统之间水动力干扰的研究方法,作为进一步研究的参考。     

动力定位船舶水动力参数数值试验研究

研究一艘动力定位船舶从浅水40m到深水5000m的水动力学参数随水深变化的规律，数值试验结果表明，在浅水深时，一方面，3个垂向运动（垂荡、横摇和纵摇）附加质量有显著增加；另一方面，6自由度运动的阻尼系数均有明显增加，特别是横摇阻尼系数，随着水深吃水比的减小而成倍数增长。而当水深达到300m以后，随着水深的增加水动力学系数变化很小。     

导数与对称导数的关系

本文揭示通常导数与对称导数的关系,将通常导数的运算性质推广到对称导数上。     

导数问题中的常见模型应用

在高中导数的应用中习题种类繁多,结构错综复杂’解题 方法更是层出不穷、千变万化。而学生面对新知识时往往回顾 老师讲过的、自己做过的旧问题的解决问题的途径’目的是寻 求出参照物’对其模仿’进而解决新问题。现把导数中常见常 用的模型加以小结,在解决导数综合问题时能够广泛联想,问 题等价转化后能发现应用模型’从而解决问题。     

Mike11一维水动力模型在桥梁壅水计算中的应用

针对新建桥梁壅水的特点,采用Mike11一维水动力模型计算了一典型河流桥梁修建前后水位壅高值,并且与经验公式计算值和Hec-Ras模型计算值进行了比较。水位壅高相差不大,壅水影响长度相差略大,故仍需进一步探索研究。     

单侧导数与导数的单侧极限

单侧导数与导数的单侧极限是微积分中两个重要概念,在求分段函数的导数,付里叶级数中都有其广泛的应用,本文讨论了这两个概念的关系.     

轴流泵叶片的水动力性能研究

根据叶片绕流理论,用保角变换和级数展开的方法推导出由变换系数表示的叶片表面的速度分布,给出了轴流泵可调叶片的水动力矩数学模型及可靠性分析。最后,对某泵可调叶片的水动力矩进行了计算。研究表明,方法是可靠的,结果令人满意。     

浅谈直流锅炉水动力事故及处理

大型锅炉在事故发生和处理中最显著的特点是时一般常见的典型事故能够自动进行处理,既增加了设备运行的安全性又增加了保护误动的可能性.本文着重对直流锅炉水动力事故及处理进行详细探讨.     

基于RMA2模型雨污排放沟渠的水动力特性分析

为了将合流制排放的污水中颗粒污染物沉积在特定区域,利用RMA2模型分析排放沟渠形态改造前后的流场变化,模拟结果看通过修整和改造后沟渠内流速降低,有利于颗粒物沉降,改造方案切实可行。     

导数极限定理的推广

导数的极限定理是数学分析中较重要的一个定理,既是导数的性质之一,又是求函数导数的工具.将导数极限定理推广到了高阶导数、偏导数、方向导数,从而得到了求高阶导数、偏导数以及方向导数的一个重要工具.     

船舶操纵运动方程系数的系统辨识

作者设计并制作了伪随机二进制(PRBS)信号发生器。并以PRBS信号操舵,辨识了船舶操纵运动方程的系数。用离散时间测量决定线性连续时间模型参数。给出了Mariner标准模型和一艘渔轮的辨识结果,并与标准的Nomoto K,T计算结果进行了比较,结果令人满意。     

Steering Dynamics in the Dutch Education System

Based on detailed empirical analyses, we paint a layered picture of emerging steering dynamics. Inspired by Foucault, we put the focus on roles stakeholders define both for themselves and others, how they give sense to policy, how they work together in policy elaboration and implementation, and the subtle and sometimes deceitful function of soft policy instruments such as information, communication, support and research. The policy to stimulate ‘schools as learning organisations' in secondary education in the Netherlands is used as a case study. The Dutch education system is one of the most decentralised en complex systems in the world. While central Government aims to turn schools into learning organisations, it has no formal responsibility nor any direct means of control in this area. The study draws information from (1) relevant government reports, policy documents and websites and (2) semi‐structured interviews with key actors. Data analysis consisted of data reduction through coding and memoing, data displays in tables and networks, and drawing and verifying conclusions. In the ground layer of the steering picture, we reconstruct how ‘schools as learning organisations' came to be a topic for Government policy. The next layer identifies 20 (networks of) actors who play a substantial role in steering. The mutual relationships between the main actors are manifold, while funding appears to be an important means for the Ministry to position actors in a steering network. A wide array of steering modes was identified. The last step in our analysis adds a dynamic element to the picture, as we look at how different actors interact, starting with how actors envision their own steering roles and the role of others. The non‐complementary role definitions that were identified in the documents, were confirmed in the interviews. Our results illustrate, in Foucault's terminology, different processes of responsibilisation and normalisation. Above all, the study illustrates that the theoretical framework provides a promising starting point for the empirical study of steering dynamics in complex education systems.     

船舶参-强横摇动力学系统的调和解分岔与次调和解分岔

应用平面周期系统的Poincaré映射、Poincaré定理以及m阶次调和解和Melnikov函数,系统地论证了船舶参-强激励非线性横摇动力学系统存在调和解和次调和解。     

船舶参—强横摇动力学系统的调和解分岔与次调和解分岔

应用平面周期系统的Poincaré映射、Poincaré定理以及m阶次调和解和Melnikov函数,系统地论证了船舶参-强激励非线性横摇动力学系统存在调和解和次调和解。     

Steering Dynamics in Complex Education Systems. An Agenda for Empirical Research

Many policy systems and education systems have grown more complex in the last three decades. Power has moved away from central governments in different directions: upwards towards international organisations, sideways towards private institutions and non‐governmental organisations and downwards towards local governments and public enterprises such as schools. Where once we had central government, we now have governance, which can be defined as the processes of establishing priorities, formulating and implementing policies, and being accountable in complex networks with many different actors. Steering in such complex education systems emerges from the activities, tasks and responsibilities of state and non‐state actors, operating at different levels and from different positions and often has un‐deliberate, un‐intentional and un‐foreseen consequences. There are many conceptual models that encapsulate this complexity, but this article suggests that there is a real need for empirical research. Without empirical research it remains unknown whether and how steering in complex networks works out in practice, what are its effects and for whom. Moreover, it is only through empirical research that we can find out whether central government has become less dominant, or rather whether its appearance has changed and it has become less visible, but not necessarily less influential. Foucault's governmentality perspective is a useful notion on which to build such a framework for empirical research which allows for a careful study of the interactions that signify steering. Inspired by Foucault, this article develops a trilogy of assumed conditions for steering to take effect in modern societies. Following this reasoning, ‘something' first needs to be made thinkable, calculable and practicable by different actors for steering to occur. This trilogy is a promising starting point for empirical research into very specific phenomena which can help us to understand how steering in complex education systems works.     

船舶二冲程柴油机热力过程仿真研究

文章根据船舶二冲程柴油机换气阶段不同于四冲程柴油机的规律,建立了船舶二冲程柴油机缸内热力过程仿真模型,研讨了模型仿真的边界条件。     

稻纵卷叶螟实验种群模拟模型

通过5种温度处理(19℃,22℃,25℃,28℃和31℃),探讨稻.卷叶螟实验种群的数量动态.25℃度温度处理组的世代存活率最高(19.7%),种群增长指数最大(14.9倍)。上述两项指标最低的是19℃温度处理组,分别为3.59b和1.18.根据实验结果,组建了该虫实验种群生命表,并建立了模拟种群数量变化的连续模型和等龄期结构的矩阵模型。     

作为意识形态的学校与职业教育课程的学问化

学问化是当前我国职教课程的核心特征与根本缺陷。这是由于普通学校的教育理念上升到整个学校体系,成为统括所有学校的意识形态所致。普通学校的理念可归纳为四个方面:课程内容理论化、学习方式课堂化、学习结果文凭化和学校组织制度化。教育大众化内在地需要学校类型多样化,而学校类型多样化的关键在于课程知识多样化。     

数学解题中反射原理的应用

介绍镜面成像原理(反射原理)，结合实例阐述物理中镜面成像原理解决数学问题的方法．进一步介绍镜面成像原理在求最大值和最小值问题中的应用。     

基于SVM的汉语动词短语识别

支持向量机(Support Vector Machines，SVM)是一个很有前途的分类新技术。本将支持向量机应用到汉语短语识别中，提出了一种基于支持向量机的汉语动词短语自动识别算法的设计与实现，和传统的基于规则的方法相比取得了比较满意的结果。