应用TESTWORK3.02软件测试不锈钢带的力学性能

介绍了用ＴＥＳＴＷＯＲＫ３．０２测试软件对不锈钢带力学性能的测试过程。从而获得了不锈钢带的弹性模量、抗拉强度、非比例伸长应力、断后伸长率等指标。     

模数法在铸钢件冒口设计中的应用

铸钢件需要冒口进行补缩，模数法设计冒口比较科学，即Mw≥M件及ε(V冒 V件）≤VWη冒口就有足够的液体补缩铸件，实现铸件无缩松，缩孔等疵病，保证铸件质量。     

直升机尾桨毂拉扭条的设计与制造

拉扭条结构件是直升机主桨毂、尾桨毂通常采用的一种结构承载受力件。本文以直11型机尾桨毂拉扭条为例，详细介绍了直升机尾桨毂拉扭条的结构设计、材料选择、设计计算和加工工艺，对相关的试验情况也进行了介绍。     

Depeaking – economic optimization of air traffic systems

More than half of all flights in and out of Frankfurt International Airport are conducted by Lufthansa airlines, as it is one of their two major hubs. The so called hub and spokes systems allow airlines to bundle major passenger flows via connecting flights across the in- and outbound traffic. The reliability of these transfer connections, and specifically the arrival punctuality at the hub airports are crucial to the economics of the daily operation.Since Frankfurt International Airport has lately been one of the most congested airports in Europe, delays (in particular arrival delays) have increased quite significantly throughout the last years. To compensate for additional queueing time in the arrival processes, the scheduled block times inbound Frankfurt were continuously adjusted upwardly keeping the arrival punctuality (and thereby the connection reliability) close to stable. The two disadvantages of this approach have been the decrease in aircraft productivity and over-deliveries in peak hours, which in turn induce either additional block time delay or ground delay programs inbound Frankfurt.This paper introduces an iterative stochastic-simulation approach that models the vicious circle of lengthening block times and increased over-deliveries. In a second step it quantifies the operational and economical effects of depeaking the schedule and illustrates the overall growth potentials for the depeaked operation of the airport. The schedule was successfully implemented in Frankfurt in summer 2004.     

电子束熔化成形Ti-6Al-4V钛合金研究进展和应用现状

电子束熔化成形技术(EBM)具有成形速度快、能量利用率高和真空环境无污染等优点,适合于Ti-6Al-4V钛合金的制备,在航空航天、生物医疗等领域得到广泛应用。然而,EBM成形Ti-6Al-4V钛合金构件仍然存在的内部孔隙、粗糙的表面和残余拉应力等缺陷,严重影响了成形件的疲劳性能。通过工艺参数的优化及后处理工艺,如热等静压和表面处理等,可以显著改善EBM成形件的疲劳性能。综述了EBM成形Ti-6Al-4V钛合金的成形工艺、微观组织、力学性能和典型的应用现状。重点讨论了影响疲劳性能的因素,并总结了一些提高疲劳性能的后处理方法。最后对EBM技术未来的发展前景进行了展望。     

一种氧杂蒽酮类海洋抗污损天然产物振动光谱的理论研究

基于 Gaussian 09W软件包,采用 DFT-B3LYP方法,研究了 1种来源于红树林未知真菌的海洋抗污损天然产物——6,8-di-O-methyl versiconol。先用 3-21G基组,再用 6-311G基组计算了分子的最稳定构型及其前线分子轨道分布。分析稳定构型发现,以蒽二酮为主体的分子是 1个三维非平面的结构,并且分子内部形成了 1个大的 π共轭体系。在最稳定构型的基础上,用同样的理论方法和 6-311G基组计算了该分子的红外振动频率及拉曼光谱频率,根据红外和拉曼光谱的振动频率特点,将红外光谱和拉曼光谱分成 3个区域,讨论了 2种光谱在各区域的特征峰的位置、振动特点、振动模式等,为氧杂蒽酮类海洋抗污损天然产物分子的振动光谱检测和分子结构的鉴定,提供了光谱解析方面的理论依据。     

单恒流源电流频率转换技术研究

本文设计了一种单恒流源电流频率转换电路,使电路的功耗减小一半,更加小型化,并且具有更好的对称性和精度.提出并从原理上论证了这种单恒流源I/F技术的理论依据,设计出相应的硬件电路,验证其原理的正确性和工程上的可行性.为单恒流源I/F技术的研发,拓展了思路,奠定了基础.     

Swiss neutron monitors and cosmic ray research at Jungfraujoch

This review summarizes the history of cosmic ray research at Jungfraujoch, the installation of three neutron monitors in Switzerland, and highlights a few of the main results by the Cosmic Ray Group of the Physikalisches Institut, Universität Bern, Switzerland. In addition, the outstanding scientific and personal contribution of the late Hermann Debrunner, the longtime leader of the Bern Cosmic Ray Group, is honored.     

Longitudinal differences in the equatorial spread F characteristics between Vietnam and Brazil

We present the results of a comparative study of the equatorial spread F (ESF) and the F layer critical parameter, the base height of the F layer bottomside (h′F) over the two equatorial sites, Ho Chi Minh City – HCM (dip latitude: 2.9°N) in Vietnam and Sao Luis – SL (dip latitude: ∼2°S) in Brazil. The study utilizes simultaneous data collected by a CADI at HCM and a digisonde at SL during the year 2002 with the monthly mean solar 10.7 cm flux (F10.7) varying from ∼120 to ∼185. This study focuses on the quiet time seasonal behavior of the F layer parameters in the two widely separated longitude sectors, and addresses the question as to what can we learn from such comparative studies with respect to the ambient ionospheric and thermospheric parameters that are believed to control the ESF generation and hence its longitudinal occurrence pattern. The observed differences/similarities in the diurnal and seasonal patterns of the F Layer height vis-à-vis the ESF occurrences are evaluated in terms of the known longitudinal differences in the F layer heights, thermospheric meridional winds and the geomagnetic peculiarities of the two sites.