室火轰燃的大涡模拟

采用一套修正的适用于低马赫数浮力流的N-S方程组来描述火灾场,运用Smagorinsky亚格子模型的大涡模拟方法对室内池火的轰燃发展过程进行了数值模拟,把模拟与实验结果进行了对比和分析。结果表明,该方法能较好地预测轰燃。同时模拟结果显示火焰区向房间后部偏转稍大,近壁处温度预测的误差大一些,随着亚格子模型的不断完善和计算能力的提高,用该技术来预测轰燃现象会更加准确。     

电磁环境对电子装备影响及复杂度计算方法

电磁环境对不同电子装备的影响存在差异,导致无法用一种方法对复杂度进行度量.在分析电磁环境对电子装备影响的基础上,将电子装备分为两类:发射并接收电磁信号的装备和接收非合作目标电磁信号的装备.以通信侦察装备和通信装备为例,研究了电磁环境对电子装备的影响,并分别给出了两类电子装备对应的复杂度计算指标和计算方法.提出的计算方法可以有效地分析电磁环境复杂度,为电磁环境复杂度计算和电磁环境构建提供技术参考.     

航天器共因失效分析与预防初探

简要介绍了共因失效相关概念及分析方法,通过共因失效案例分析,对航天器如何开展共因失效分析以及如何预防共因失效进行了初步探讨,提出了航天器开展共因失效分析的定性和定量方法以及预防共因失效的措施。     

GNSS reflectometry and remote sensing: New objectives and results

The Global Navigation Satellite System (GNSS) has been a very powerful and important contributor to all scientific questions related to precise positioning on Earth’s surface, particularly as a mature technique in geodesy and geosciences. With the development of GNSS as a satellite microwave (L-band) technique, more and wider applications and new potentials are explored and utilized. The versatile and available GNSS signals can image the Earth’s surface environments as a new, highly precise, continuous, all-weather and near-real-time remote sensing tool. The refracted signals from GNSS radio occultation satellites together with ground GNSS observations can provide the high-resolution tropospheric water vapor, temperature and pressure, tropopause parameters and ionospheric total electron content (TEC) and electron density profile as well. The GNSS reflected signals from the ocean and land surface could determine the ocean height, wind speed and wind direction of ocean surface, soil moisture, ice and snow thickness. In this paper, GNSS remote sensing applications in the atmosphere, oceans, land and hydrology are presented as well as new objectives and results discussed.     

大学生就业报道的内容分析——以《中国青年报》为例

通过《中国青年报》关于大学生就业报道内容的分析,得出其立足点与政府立场和就业政策的高度一致,注重报道和反映大学生自主创业和到基层就业的内容,并在报道中呈现出其报道的服务性、实用性等特点。     

蝴蝶翼面形状对绕流结构的影响

蝴蝶的扑翼飞行因其相对翼展较大、扑翼频率低等特点引起广泛关注,尤其是具有越洋迁徙特性的蝴蝶更是备受瞩目。本文以天堂鸟翼凤蝶和黑脉金斑蝶这两种长距离迁徙蝴蝶作为研究原型,利用氢气泡流动显示技术研究这两种不同外形的蝴蝶翼面绕流结构随迎角的变化。在相同的实验条件下,两种模型翼面绕流均出现前缘涡、翼尖涡等流动结构,且绕流结构随迎角的变化趋势基本相同。但由于翼面外形的不同,两种模型在前缘涡的形态、强度及后翼面翼尖绕流结构等方面表现出一定的差异。     

运用GPS空中校正飞机无线电罗差误差分析

针对某些特种飞机无线电罗差无法沿用传统校正方法在地面进行校正的状况 ,首次提出了运用 GPS接收机在空中校正飞机无线电罗差的方法。本文对影响该校正方法校正精度的各项误差因素进行了分析。     

Structure and kinetic properties of slow-mode shocks associated with magnetic reconnection in the near-Earth magnetotail

We study the structure and kinetic properties of slow-mode shocks near the plasma sheet boundary layer (PSBL) associated with magnetic reconnection by Cluster observation. The presence of slow-mode shocks is confirmed by traditional Rankine–Hugoniot (RH) analysis and Monte-Carlo shock fitting method. The Walén analysis, applied to the tailward flow associated with slow-mode shocks, also supports that plasma was accelerated across a Petschek-type slow-mode shock connected to the diffusion region. Back-streaming ions were observed on the shock layer, and cold ions were accelerated and heated by slow-mode shocks. In addition, whistler and electrostatic solitary waves were observed around the slow-mode shocks. These waves might be excited by the observed field-aligned electron beams near the shocks.     

安全阀性能检测系统的测量不确定度

分析了安全阀性能检测系统中的主要误差因素，对安全阀动作性能和排量系数的测量不确定度进行了初步计算。     

声强测量的有效性分析及其在国产轻型飞机上的应用

本文对声强测量的有效性作了较全面分析，为精确的声测量奠定了基础。分析结果应用于某型飞机的声强测量中，为该型飞机的降噪工作提供了可靠的数据来源。