Research status of key techniques for shock-induced combustion ramjet(shcramjet) engine

As one of the most promising propulsion systems in the future,shock-induced combustion ramjet engine can remedy the disadvantages in the integrated design of scramjet engine and airframe.It can shorten the length of the combustor,lighten the structure weight of the engine and keep better performance in a broad range of flight Mach number.The elementary principle of shock-induced combustion ramjet engine is introduced.The key technologies of this kind of propulsion system are described,while their research s...     

Premature termination in couple therapy with veterans: Definitions and prediction of long-term outcomes.

Premature termination (PT) has been identified as widespread in individual, family, and couple therapy. Unfortunately, research on PT utilizes numerous definitions of PT without providing guidance on which definition may be most clinically useful. The current study investigated seven definitions of PT (three based on therapist ratings and four based on quantitative measures) utilizing a sample of 177 couples seeking treatment at two Department of Veterans Affairs medical centers. Results indicated that PT occurred in 50–80% of couples; however, agreement between the definitions of PT was generally only in the slight to fair range, making it difficult to determine whether a particular couple was ready to terminate treatment. Additionally, many commonly used definitions of PT were unrelated to level or maintenance of relationship functioning following treatment. In contrast, two definitions of PT (ending treatment in the distressed range and therapist-rated likelihood of future unhappiness) significantly predicted larger decreases in relationship satisfaction during the 18 months following therapy, as well as lower levels of satisfaction and relationship stability 18 months after termination. Additionally, long-term relationship functioning was especially poor when both these definitions of PT were met, suggesting that both qualitative and quantitative definitions should inform decisions about termination in couple therapy. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Mechanism of simultaneous tripping of ground directional relays in a 6.6‐kV distribution system

In Kyushu Electric Power's 6.6‐kV distribution system, after a single‐phase ground fault occurred in the circuit of a distribution line, we experienced a phenomenon in which the analogue ground directional relays of the other circuits linked to the same bank were simultaneously tripped. In this paper, focus is placed on the mechanism and possibility of simultaneous tripping of ground directional relays. This mechanism was examined in an experiment carried out using an analogue simulator. The results of the test revealed that such simultaneous tripping was attributable to the neutral instability phenomenon of grounding potential transformers installed in an isolated neutral system. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(2): 23–30, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20919     

高校大学生逃课现象调查与研究

针对目前大学生逃课情况较为严重的现状,本文通过对某高校大学生的调查,分析引发大学生逃课的原因,并有针对性地提出一些建议来减少大学生逃课,从而达到提高高等教育教学质量的目的。     

具有振动支点的弹簧摆的共振分析

研究了支点沿垂直方向谐振的弹簧摆的运动，其运动由两个相互耦合的常微分方程描述。用多尺度法分析了当激励濒率Ω≈ω１，ω２时的共振行为，并分析了当ω１／ω２≈２．０时的内共振响应，发现了存在饱和现象，找到了参数共振时的不稳定区域。     

基于素描的遗传算法

传统遗传算法容易陷入局部最优解，本文借鉴美术中“素描”的思想，对传统的遗传算法进行了改进，提出了基于素描的新型遗传算法．该算法模拟人的素描行为，构造参数控制下的选择算子，再通过参数的调节来选择个体，并依据最优个体对选择算子进行修正，以达到动态调整群体进化过程中的种群多样性和收敛速度之间的矛盾，从而有效地避免了传统遗传算法中早熟现象，显著地提高了GA对全局最优解的搜索能力和收敛速度．这将使GA在众多实际的优化问题上将具有更广泛的应用前景．仿真结果表明，该算法正确有效，且性能优于现有的其它方法．     

激波作用非晶态合金FeCuNbSiB的物理冶金效应研究

本工作介绍了非晶态合金FeCuNbSiB在激波冲击作用下转变成具有纳米尺寸的多晶相材料这一新的物理冶金应,并用XRD,TEM,DSC技术对实验结果进行了研究.结果表明,尽管激波晶化时间极短,却具有极高的转变速率,晶化时间仅为退火晶化时间的10-6～10-9,晶化度却接近100%.和退火晶化相比,这些结果很难用传统的固态扩散相变理论解释.激波纳米晶化这种新的物理冶金效应可能进一步改进和完善传统的晶化理论.     

载水油气井生产测井方法研究

油井或气井出现载水现象后,不断上升的水柱不仅会降低储层与井筒间的压差影响油气产出,而且改变了井筒中流体介质分布和速度分布,造成生产动态监测方面的困难。提出了依据流量计、密度计、持水率计等曲线判断油井或气井是否载水的新方法,基于对不同井段的流型进行了分析,提出了相应产出剖面测井仪器系列及其测井资料处理解释模型。     

基于免疫更新机制的遗传算法及其在规划问题中的应用

受生物体免疫系统抗体更新机制的启发，将抗体更新机制引入遗传算法，从而保证抗体遗传子的多样性，有效地防止了遗传操作中的早期收敛。对遗传子进行分段编码以对应多道染色体，进而克服了传统遗传算法只能对二值染色体进行操作的缺陷。应用实例证明了该方法的有效性。     

改进型遗传算法及其在数据挖掘中的应用

文中在简单遗传算法的基础上，利用改进的算法进行关联规则的发现和数据库中特征项权重的发现，通过对农业气象数据库的实验，力求解决遗传算法中的早熟等问题。