D406A钢A-TIG的焊接性试验

针对6.5 mm厚D406A超高强度钢采用活化剂进行A-TIG焊接试验研究,对焊缝外观成型、焊缝熔深、接头显微组织以及接头力学性能进行综合分析,研究了活化剂涂敷量和焊接工艺参数（焊接电流、焊接电压、焊接速度）对A-TIG焊缝熔深和熔宽的影响。结果表明,在相同焊接参数下,使用活化剂可使焊缝熔深比常规TIG焊增加一倍以上,焊缝成型良好。活化剂的涂敷存在最佳的涂敷量,焊接电流、焊接电压和焊接速度等焊接参数的变化,对焊缝熔深和深宽比的变化产生不同影响。     

超高强度铝合金的发展与应用

本文以Ｂ９６、７０９０、ＣＷ６７及７０５５等合金为典型，对国外超高强度铝合金的发展与应用进行了评述，初步介绍了国内７Ａ５５合金的发展现状，并与国外同类材料进行了对比。通过分析发现，７０５５、７Ａ５５和７０９０等超高强度铝合金与目前常用的高强铝合金（如７０７５、７１５０等）相比，在塑韧性相当的前提下，强度均有较大幅度的提高。     

Expectations for Crater Size and Photometric Evolution from the Deep Impact Collision

The NASA Discovery Deep Impact mission involves a unique experiment designed to excavate pristine materials from below the surface of comet. In July 2005, the Deep Impact (DI) spacecraft, will release a 360 kg probe that will collide with comet 9P/Tempel 1. This collision will excavate pristine materials from depth and produce a crater whose size and appearance will provide fundamental insights into the nature and physical properties of the upper 20 to 40 m. Laboratory impact experiments performed at the NASA Ames Vertical Gun Range at NASA Ames Research Center were designed to assess the range of possible outcomes for a wide range of target types and impact angles. Although all experiments were performed under terrestrial gravity, key scaling relations and processes allow first-order extrapolations to Tempel 1. If gravity-scaling relations apply (weakly bonded particulate near-surface), the DI impact could create a crater 70 m to 140 m in diameter, depending on the scaling relation applied. Smaller than expected craters can be attributed either to the effect of strength limiting crater growth or to collapse of an unstable (deep) transient crater as a result of very high porosity and compressibility. Larger then expected craters could indicate unusually low density (< 0.3 g cm⁻³) or backpressures from expanding vapor. Consequently, final crater size or depth may not uniquely establish the physical nature of the upper 20 m of the comet. But the observed ejecta curtain angles and crater morphology will help resolve this ambiguity. Moreover, the intensity and decay of the impact “flash” as observed from Earth, space probes, or the accompanying DI flyby instruments should provide critical data that will further resolve ambiguities.     

江苏省CBERS-1卫星红外数据应用示范研究评价

文章对CBERS -1卫星IRMSS数据从空间分辨率、几何精度、噪声等方面作了分析评价 ,选取典型的南京地区、洪泽湖作为示范应用区 ,经过几何精纠正后的IRMSS数据进行不同地物在不同波段上的光谱采样分析 ,进行了城市信息与湖泊信息提取实验 ,效果较好 ,对南京辖区和洪泽湖的形态特征、环境因素、动态变迁等方面作了分析研究 ,从图像上可以清晰地看出南京辖区水体、城建和交通以及郊区的农林状况、洪泽湖河口淤积、岸边污染的情况。总之 ,CBERS-1卫星IRMSS数据可用 ,质量较好 ,达到了设计要求 ,有广阔的应用前景。     

智能型减压器试验台的研制

主要介绍了基于硬件设备和软件编程基础上的智能型减压器试验台的设计与应用。测试系统保留了最通常的手动操作系统，增加了全新的自动数据采集系统。试验台可精确、同步测量高入口压力值时的瞬时出口压力值，同时，增加了入口压力控制系统，大大提高了工作效率。     

A/D量化对GPS接收机自适应天线性能的影响

A／D量化会带来干扰抑制比和输出卫星信噪比的损耗。通过估算量化噪声和干扰信号互相关矩阵的最大特征值，给出了干扰抑制比的近似表达式，而输出卫星信噪比损耗则是通过计算高斯噪声下量化信号的一阶矩和二阶矩得到的。结果表明，当选择量化间隔△-0．5d(α^2为接收信道的热噪声功率)时，量化噪声近似为独立的均匀分布的白噪声，因A／D量化带来的输出卫星信噪比的损耗不大于0．1dB，干扰抑制能力几乎不受影响。计算机仿真实验也验证了所作分析。     

FY-1C/D极轨气象卫星空间粒子成分监测器及其在轨探测结果

介绍了风云一号(FY-1)C，D极轨气象卫星空间粒子成分监测器的任务目标、主要功能和工程指标。以及数据的获取和处理方法。给出了空间环境宁静期、地磁扰动事件、太阳质子事件、与太阳活动的关系和粒子长期变化等探测结果，并进行了相应的分析。对C，D星空间粒子成分监测器分别进行的5年和第二次在轨测试结果表明，两星监测器工作正常、性能稳定，探测数据可靠。     

CBERS-1红外遥感器图像处理系统设计

红外多光谱扫描仪（IRMSS）是中巴地球资源卫星（CBERS）上的重要有效载荷之一。其获取的红外图像可以在国民经济的各个领域得到广泛应用。但是由数传系统传回的图像数据不能直接用,必须经过相应的处理。文章介绍的内容就是如何设计一个处理系统,将这种不可直接用数据经过解码和图像格式的处理,得到可视图像;经过图像预处理,得到零级图像;经过相应的辐射校正处理,得到一级图像:经过几何校正处理,得到二级图像产品,提供给其它经济各部门加以应用。     

Gas permeability and flow characterization of simulated lunar regolith

Recent discoveries of water ice trapped within lunar topsoil (regolith) have placed a new emphasis on the recovery and utilization of water for future space exploration. Upon heating the lunar ice to sublimation, the resulting water vapor could theoretically transmit through the lunar regolith, to be captured on the surface. As the permeability of lunar regolith is essential to this process, this paper seeks to experimentally determine the permeability and flow characteristics of various gas species through simulated lunar regolith (SLR). Two different types of SLR were compacted and placed into the permeability setup to measure the flow-rate of transmitted gas through the sample. Darcy’s permeability constant was calculated for each sample and gas combination, and flow characteristics were determined from the results. The results show that Darcy’s permeability constant varies with SLR compaction density, and identified no major difference in permeable flow between the several tested gas species. Between the two tested SLR types, JSC-1A was shown to be more permeable than NU-LHT under similar conditions. In addition, a transition zone was identified in the flow when the gas pressure differential across the sample was less than ∼40 kPa.     

基于Linux的触摸屏设备驱动的设计

以三星公司的S3C2440A处理器为平台，介绍了linux操作系统下四线电阻触摸屏的驱动程序的设计开发过程，详细阐述了触摸屏设备驱动程序的设计过程，并将设计好的驱动程序注册到linux内核中。最后将触摸屏设备驱动程序加入到linux内核中编译成内核映像，并烧写到S3C2410A处理器中测试该驱动程序。