有机高分子絮凝剂处理高浊度原水效果和机理研究

本文研究了有机高分子絮凝剂ＰＡＭ、ＣＴＡＢ及它们的复配ＰＡＭ＋ＣＴＡＢ处理高浊度原水的最佳实验条件、絮凝性能、效果和机理，为有机高分子絮凝剂的选择和管式絮凝器的研制提供了理论依据。     

斜置尾桨对直升机飞行特性的影响

基于叶素理论建立了斜置尾桨的数学模型,以UH-60A直升机为对象,计算了平飞配平特性,并与试飞结果进行对比,完成了对模型的验证。验证结果表明,所建的斜置尾桨模型合理准确,能满足工程精度。本文从直升机悬停需用功率研究了尾桨斜置角的设计,计算了不同尾桨斜置角对直升机悬停需用功率的影响,得出UH-60A直升机的尾桨斜置角优化值为20~25°。通过计算和对比斜置尾桨与常规尾桨直升机的平飞配平特性,得出尾桨斜置主要影响直升机的纵向配平特性。最后,对斜置尾桨的利与弊进行了一些讨论。     

7075Al/SiCp复合材料热压缩变形的研究

采用圆柱试样在Gleeble-1500热模拟机上对7075Al／SiCp复合材料进行高温压缩变形实验，变形温度为300-500℃，应变速率为0．001-1s^-1。结果表明：7075Al／SiCp复合材料的流变应力大小受变形温度和应变速率的强烈影响，流变应力随应变的增加而逐渐增加，出现一峰值后逐渐下降；流变应力随变形温度的升高，应变速率的降低而降低。可用Zener—Hollomon参数的双曲正弦形式来描述7075Al／SiCp复合材料高温压缩变形流变应力，其变形激活能Q为279．659KJ/mol。     

Ca的掺入对复合氧化物LaFeO3和LaMnO3的结构及电性的影响

用柠檬酸法、固相法制备了替代的复合氧化物Ｌａ１－ｘＣａｘＦｅＯ３及Ｌａ１－ｘＣａｘＭｎＯ３。对样品进行了ＸＲＤ及导电能力测试。结果表明：Ｘ≤０．５,复合氧化物为单相的钙钛矿结构;Ｃａ的掺入,改善了ＬａＦｅＯ３导电性能,使其室温电阻率从６×１０＾４Ω·ｃｍ降低到１０Ω·ｃｍ左右;而对ＬａＭｎＯ３的影响不大,其室温电阻率在１０＾－１Ω·ｃｍ左右。     

铜与铜镶嵌非晶体焊料点焊的研究

研究了铜与铜镶嵌非晶体焊料ＱＪＹ－５Ａ、ＱＪＹ－５Ｂ点焊,以及调整点焊温度场来降低焊接区铜的熔点,提高焊接区电能利用率的措施;叙述了铜与铜镶嵌ＱＪＹ－５Ａ、ＱＪＹ－５Ｂ焊料点焊焊核形成过程及特点。     

BMCMC法分析2009年墨西哥H1N1流感病毒与中国流感病毒的进化关系

从GenBank上下载所有1978-2009年在中国分离的H1N1亚型流感病毒的HA和NA基因及所有同期在中国分离的A型流感病毒(宿主包括人、猪和禽)的PB1、PB2、PA、NS、NP和M基因的序列,将这些基因序列与2009年在中国发生的墨西哥H1N1流感病毒的对应基因序列进行BMCMC法分析,绘制BMCMC进化树,结果揭示中国发生的墨西哥H1N1流感病毒的HA和NA基因相对独立于中国季节性H1N1流感病毒;M基因相对独立于中国国内的季节性流感病毒和禽源流感病毒;PB1基因包含在季节性流感病毒的分群内;PB2基因和NS基因与国内重排的流感病毒相关,但相对独立于国内的季节性流感病毒和禽源流感病毒;PA基因包含在国内禽流感病毒的分群内;NP基因则与国内传统的猪流感病毒相关,但相对独立于国内的季节性流感病毒和禽源流感病毒.     

Deep Impact: Working Properties for the Target Nucleus – Comet 9P/Tempel 1

In 1998, Comet 9P/Tempel 1 was chosen as the target of the Deep Impact mission (A’Hearn, M. F., Belton, M. J. S., and Delamere, A., Space Sci. Rev., 2005) even though very little was known about its physical properties. Efforts were immediately begun to improve this situation by the Deep Impact Science Team leading to the founding of a worldwide observing campaign (Meech et al., Space Sci. Rev., 2005a). This campaign has already produced a great deal of information on the global properties of the comet’s nucleus (summarized in Table I) that is vital to the planning and the assessment of the chances of success at the impact and encounter. Since the mission was begun the successful encounters of the Deep Space 1 spacecraft at Comet 19P/Borrelly and the Stardust spacecraft at Comet 81P/Wild 2 have occurred yielding new information on the state of the nuclei of these two comets. This information, together with earlier results on the nucleus of comet 1P/Halley from the European Space Agency’s Giotto, the Soviet Vega mission, and various ground-based observational and theoretical studies, is used as a basis for conjectures on the morphological, geological, mechanical, and compositional properties of the surface and subsurface that Deep Impact may find at 9P/Tempel 1. We adopt the following working values (circa December 2004) for the nucleus parameters of prime importance to Deep Impact as follows: mean effective radius = 3.25± 0.2 km, shape – irregular triaxial ellipsoid with a/b = 3.2± 0.4 and overall dimensions of ∼14.4 × 4.4 × 4.4 km, principal axis rotation with period = 41.85± 0.1 hr, pole directions (RA, Dec, J2000) = 46± 10, 73± 10 deg (Pole 1) or 287± 14, 16.5± 10 deg (Pole 2) (the two poles are photometrically, but not geometrically, equivalent), Kron-Cousins (V-R) color = 0.56± 0.02, V-band geometric albedo = 0.04± 0.01, R-band geometric albedo = 0.05± 0.01, R-band H(1,1,0) = 14.441± 0.067, and mass ∼7×10¹³ kg assuming a bulk density of 500 kg m⁻³. As these are working values, {i.e.}, based on preliminary analyses, it is expected that adjustments to their values may be made before encounter as improved estimates become available through further analysis of the large database being made available by the Deep Impact observing campaign. Given the parameters listed above the impact will occur in an environment where the local gravity is estimated at 0.027–0.04 cm s⁻² and the escape velocity between 1.4 and 2 m s⁻¹. For both of the rotation poles found here, the Deep Impact spacecraft on approach to encounter will find the rotation axis close to the plane of the sky (aspect angles 82.2 and 69.7 deg. for pole 1 and 2, respectively). However, until the rotation period estimate is substantially improved, it will remain uncertain whether the impactor will collide with the broadside or the ends of the nucleus.     

同步数字体系STM-4误码测试系统的设计

介绍 SDH.STM- 4误码测试仪的设计方案。该仪器具有价格低廉、便于携带的特点。仪器的设计重点在于STM- 4净荷提取 /插入芯片的应用和 FPGA的设计     

优化的GM(1,1)模型及其适用范围

在已有灰色理论的基础上,利用“最小二乘法”确定GM(1,1)白化权函数的时间响应函数中的常数c,摈弃了传统GM(1,1)把原始序列中x^(0)(1)作为初始条件的欠科学的做法,构建了时间响应函数的优化模型。经大量的数据模拟和预测,发现优化的GM(1,1)模型各项指标均优于传统的GM(1,1)模型,且拓宽了其适用范围。     

基于C8051F020单片机的无人机加速度采集系统

为了满足无人机三轴加速度测量与控制的需要,设计了一种简易、方便的加速度采集系统.本系统采用高集成度单片机C8051F020进行多通道数据的采集和A/D 转换,在单片机内部完成数据存储、数据处理,再利用串行通信接口将数据传送至上位机,然后由无线发射模块发送至地面接收设备.在试验条件下,可以将采集到的数据传送至PC机进行分析或者由液晶显示仪显示.