Letter to the editor

The purpose of homeland security is to protect a nation from harm. A specific government agency called the Department of Homeland Security was established in the United States just after the September 11, 2001, attacks. The scope of this department is varied with emphasis on efforts to prevent terrorist attacks, reduce vulnerability, and maximize response capabilities. It also handles preparedness and responsiveness for natural disasters. Border security, both land and maritime, is clearly an important and interesting area of focus for homeland security.     

Letter to the editor

I recently joined AESS, in part, out of selfish self-interest and for career development reasons. Aerospace systems, the technology of packaging, applications design, development, and testing, have unique and demonstrable use in other areas of systems engineering and scientific research.     

Letter to Editor-electrolysis heat

The letter refers to the Toby Grotz's paper “Novel Means of Hydrogen Production Using Dual Polarity Control” and Waiter Russell's “Experiments with Zero Point Energy” presented at the 27th IECEC in San Diego in 1992. Commercial air to air heat pumps typically exhibit a COP, coefficient of performance, of 1.5, which means they deliver 1.5 units of thermal energy for each 1.0 units of electrical energy input. It is more likely that these 'Zero Point' effects are the electrical analogue of a mechanically powered vapor compression refrigeration cycle. The electrolyzer phenomenon reported by Grotz and others, if true, is a heat pump. Another commercial example of an all electrical, non-mechanical, refrigeration cycle heat pump are the in-room refrigerators in Japanese hotels, which utilize the reverse thermoelectric effect. Readers are reminded that the so-called “Zero Point Effect” is not producing more energy than is supplied to the systems, just that the COP mechanism is not yet understood in this case. The editor's response to the unexplained heat release during electrolysis is presented. He describes the experiment which was carried out with electrolysis currents ranging up to 75 amperes. For each temperature rise the resistance heating required more power than did the electrolysis process. The electrolysis had even delivered additional power in the fuel value of the released hydrogen, which was dissipated into the air. The authors calculated that making a gallon of such water would release the energy equivalent of 30 gallons of gasoline     

Hale引理证明的修正

本文指出了著名的Ｈａｌｅ引理证明中的不足之处,并给以完善。     

NUM-1060 Ⅱ CNC系统自动回零程序设计

本文介绍了采用NUM-1060ⅡCNC系统，在设计制造CX600数控车铣加工中心过程中，通过E变量判断回零状态，调用Part功能子程序，完成自动回零的方法。该方法切实可行，已用于生产实际。     

大型飞机翼身对接形式分析

介绍了大型飞机伊尔76机翼机身对接部位结构的布置、材料使用、传力特性及对接形式的特点。此对接形式传力路线清晰，传力直接并实现多路传力，破损安全特性良好。装配上留有工艺补偿余量，降低了安装难度，并且不会损坏中央翼整体油箱的密封性。但中梁翼身对接时、对接接头往下伸出中央翼密封区，与机身采取双耳对单耳的叉接型式，每组耳片上采取多个螺栓连接，这种方式难以精确估算每个螺栓传递的载荷，会增加结构连接重量，也增加了装配的难度，值得进一步探讨。     

P2P模式的系统结构研究

本文首先介绍了什么是P2P和它的基本运作模式。详细阐述P2P模式的主要形式及其相应的系统结构。     

空客远程飞行的新纪元:A340-600

A340-600是空客在新千年展示的第一架新飞机,也是空客进行一体化改制后推出的第一架新飞机.A340-500/600项目于1997年12月正式启动.A340-600的出现,使空中客车公司具备了可与波音747飞机直接竞争的机型,开始了空中客车公司制造大型远程飞机的新纪元.     

Chapter 8 - Dynamic Coupling to the Magnetosphere

Space Science Reviews -     

A300-600ST飞机空地数据链改装方案

空地数据链是一种基于CNS/ATM提出的新型数字通信技术,对实现地面网络与飞机的实时数据通信具有重要意义。以空客公司的A300-600ST型飞机为背景,研究提出了一种能在老型号飞机上实施空地数据链改装的技术方案,并通过可靠性分析,将改装方案定位于“小改”,从而可以有效降低适航审定工作的复杂性,为航空公司节约改装成本。此方案已于2006年在空客公司国际运输部成功应用,对其他老机型的同类改装具有一定的参考价值。     

嵇康《与山巨源绝交书》写作时间考

《与山巨源绝交书》是嵇康研究的重要作品。其写作时间学界多持魏景元二年,即公元261年。笔从本、史料出发辨析出此作品写作时间应为景元四年,即公元263年。     

直9涡轴8发动机的历程记录仪

本文简要介绍了适合直9涡轴8系列发动机使用的历程记录仪的硬件结构及软件设计原则。通过100多台的外场改装使用证明,记录仪改装简单、工作可靠,取得了满意的效果。     

大学生就业质量评价指标体系及其测算

在我国现有的政治经济制度背景和传统文化条件下,高校毕业生就业质量指标体系的基本内容应包括3个一级指标和15个分指标,并通过建立评价标准和数学模型的方法进行计算。     

童话之城——哥本哈根

哥本哈根位于波罗的海和北海之间的厄勒海峡西岸,集聚着充满童话气质的古堡与皇宫、乡村与庄园。不论是沉淀了古老历史的还是延续着皇族传奇的各类建筑,都鳞次栉比地坐落在这里。哥本哈根融合了古典与现代的艺术气息,阿肯艺术中心、路易斯安娜博物馆、国家博物馆、丹麦国家美术馆等众多艺术博物馆各领风骚。富有皇族气质的哥本哈根,贯穿着全年度的各种主题节庆,令狂欢从夏季一直延续到冬季。最著名的莫过于哥本哈根国际爵士音乐节,在每年7月将持续整整10天,着实是不容错过的年度盛会!     

GJB 904-90<锻造工艺质量控制>修订情况简介

介绍了国家军用标准《锻造工艺质量控制》修订项目的产生背景及修订的简要过程,着重明确了修订的技术性内容并阐述了标准修订后对锻造行业军工产品质量保证的有益作用。     

刚体姿态仿真方法研究

首先论述了姿态描述的四种方法:欧拉角、欧拉轴旋转参数、方向余弦和四元数法,重点介绍了四元数法在飞行器运动学上的应用,它消除了欧拉方程的奇异性,计算效率也远远优于其他三种方法;最后讨论了数值仿真的方法及误差。