民用飞机控制律对偏航机动载荷影响分析

飞机机动过程中方向舵快速大幅偏转会使方向舵和垂尾上产生较大气动载荷并传递到后机身,导致 驾驶员来回往复蹬舵造成安全事故。针对 CCAR-25部25.351条规定的偏航机动情况及 CS-25部25.353规定的偏航机动新条款——方向舵往复偏转,本文首先对两种偏航机动条款分别进行分析;然后考虑控制律进行 偏航机动情况机动仿真计算;最后通过比较分析飞机响应运动参数及垂尾载荷计算结果,并分析控制律对偏航 机动载荷的影响。结果表明:对于偏航机动,考虑控制律后飞机的响应幅度有所缓减,导致垂尾载荷有所降低; 对于偏航机动新条款,由于方向舵反向偏转导致侧滑角贡献和方向舵偏度贡献垂尾载荷两者叠加,从而导致垂 尾载荷大幅增加;P-Beta控制律有效降低了方向舵往复偏转的垂尾载荷。     

乘务类学生英语课程教学方法实证探析

通过问卷调查探析乘务类本科生对交际和非交际教学法及活动的认识和态度,旨在研究一种可以有效提高英语教学质量的方法.结果表明乘务类学生对交际教学活动和非交际教学活动都有偏好,因此对于此类学生更为有效的教学方法就是采取折中的综合性教学法.     

Attitude control system of the first Russian nanosatellite <Emphasis Type="Italic">TNS-0 no. 1</Emphasis>

The results of designing the attitude control system of the first Russian nanosatellite TNS-0 no. 1 providing orientation of its longitudinal axis along the local geomagnetic field induction vector are presented. The system consists of a permanent magnet and two sets of hysteresis rods. The magnetic and geometric parameters of the magnet and rods are calculated. The influence of the permanent magnet field on the hysteresis rods and mutual influence of the rods in the case of compact satellite packaging are analyzed. Examples of calculations of transient processes and steady-state angular satellite motion are presented.     

廊坊市市区水资源规划治理研究

水资源是人类赖以生存的资源,现今,水资源已成为制约我国民经济发展的障碍,如何在充分利用水资源、保护水资源的基础上发展经济,是实现可持续发展的重要条件。本文通过对废水排放量和规划用水量的预测,对廊坊市未来的水资源利用规划提出建议,实现可持续发展。     

电子技术基础课程研究型教学模式的探索与实践

本文首先阐明对培养学生创新意识培养的认识,然后讲述怎样结合电子技术基础课程的特点建立研究型教学模式,进而介绍丰富的教学实践,以及多层次、系列化和立体化的教材建设,最后说明教学效果。     

PID控制对线性时滞系统稳定性的研究

包含线性时滞被控对象和PID控制器在内的反馈系统的稳定性已经有多年的研究,在众多论证方法中,奈奎斯特判据、Hermite-Biehler定理、根轨迹等方法最为常见。此类研究的主要目的即是决定控制参数的稳定范围。通过有限的整定步数来明确并表示出其域值范围和计算步骤只能借助一阶被控对象得以实现,且是一次时延被控系统。本文在庞德里亚金的研究结果上,拓展出任意阶被控对象都可适用的控制算法。     

Method of designing a neural controller for the automatic lateral control of unmanned aerial vehicles

The paper discusses a method of designing the neural controller for two-channel control of a technical object by an example of the roll and yaw control depending on deviations, velocities and accelerations of their variation.     

一种型号专用电源转换器快速检定系统的研制

阐述了依据Q/W 892A-2007《电源转换器检定规程》研制的型号专用电源转换器快速检定系统。通过研制专用拔出力检定装置和多功能智能转换开关,实现由PC机通过系统软件自动控制测试仪器进行检定以及检定结果的处理,并自动生成原始记录和证书报告。系统具有自动、智能等优点,能够实现电源转换器的快速检定。经应用,降低了劳动强度,节省了时间,提高了检定效率。     

Early effects of low dose C ion or X-ray irradiation on human peripheral blood lymphocytes

The aim of this study was to estimate the acute effects of low dose ¹²C⁶⁺ ions or X-ray radiation on human immune function. The human peripheral blood lymphocytes (HPBL) of seven healthy donors were exposed to 0.05 Gy ¹²C⁶⁺ ions or X-ray radiation and cell responses were measured at 24 h after exposure. The cytotoxic activities of HPBL were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT); the percentages of T and NK cells subsets were detected by flow cytometry; mRNA expression of interleukin (IL)-2, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were examined by real time quantitative RT-PCR (qRT-PCR); and these cytokines protein levels in supernatant of cultured cells were assayed by enzyme-linked immunosorbent assays (ELISA). The results showed that the cytotoxic activity of HPBL, mRNA expression of IL-2, IFN-γ and TNF-α in HPBL and their protein levels in supernatant were significantly increased at 24 h after exposure to 0.05 Gy ¹²C⁶⁺ ions radiation and the effects were stronger than observed for X-ray exposure. However, there was no significant change in the percentage of T and NK cells subsets of HPBL. These results suggested that 0.05 Gy high linear energy transfer (LET) ¹²C⁶⁺ radiation was a more effective approach to host immune enhancement than that of low LET X-ray. We conclude that cytokines production might be used as sensitive indicators of acute response to LDI.     

LabWindows/CVI环境下调用Word文档的实现方法

目的介绍一种在Labwindows/CVI环境下调用Word的实现方法;方法结合具体的实例,实现对Word文档的调用;结果该方法可以按照规定的格式自动生成Word文档;结论提高了软件的效率和自动化程度。