消失模铸造成型用PLC控制装置研制

本文采用可编程控制器(PIG)为主要控制元件，研制出一台成型控制装置。对控制系统的硬件和软件构成、控制方式及特点作了介绍。最后利用该控制装置制作出表面光洁的优质泡沫模样。     

消失模铸造传质过程与铸件品质控制

消失模铸造是1 种有利于环保的近净成形铸造方法，在消失模工艺的浇注过程中，模样分解为液态或气态产物。为了生产合格的铸件，须选用具有合适透气性和液态产物浸润能力的涂料，以控制分解产物的传质过程。说明设计在高温下测试涂料透气性的仪器是必要的。     

采用消失模铸造工艺生产蠕铁排气出口管

介绍了消失模法生产蠕铁排气出口管的工艺过程.试验发现,采用反直浇道结合侧注的模组形式为佳,每组8件、管口朝下;涂料直接影响铸件表面积碳及皱皮倾向;并采用消失模法批量生产了蠕铁排气出口管,材料性能及金相组织达到要求,铸件壁厚均匀,表面光滑,已用于红旗轿车的部分车型.     

太赫兹波无损检测新技术及其应用

简要介绍了太赫兹波的产生、探测方法和主要特点。综述了国内外在太赫兹波领域的研究进展。以太赫兹波技术对航天飞机燃料箱绝热泡沫层成功检测为例,阐述了太赫兹波无损检测新技术的特点、适用条件和在航空航天领域的应用。     

遥感网格的数据压缩与任务分配方法研究

网格计算作为分布式计算在科学计算领域的发展方向,可以为对地观测数据的处理提供强大的计算力。在分析遥感信息服务网格节点(Remote Sensing Information Service Grid Nodes,RSSN)中网络数据传输和负载均衡两个关键问题的基础上,提出了一种有效的基于游程编码和Huffman编码的数据压缩方法和基于"计算端元"的任务分配策略,该方法针对遥感影像特点进行有效数据压缩,具有较好的压缩比,达到了17%,且能实现任务负载均衡。并在遥感信息服务网格节点计算平台上,以中国范围内1km分辨率气溶胶光学厚度(Aerosol Optical Depth,AOD)反演计算为例,从压缩率和计算时间效率方面验证和分析了上述方法的有效性。     

Seasonal variation of columnar aerosol optical properties over Athens, Greece, based on MODIS data

A long-term (2000–2005) data set of aerosol optical properties obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) is analyzed focusing on the Greater Athens Area in the Eastern Mediterranean region. The MODIS aerosol optical depth standard product (AOD at 550 nm) and its respective ratio attributed to fine-mode particles (FM) are employed to evaluate the inter-annual and seasonal variability of the aerosol properties over Athens. Based on AOD₅₅₀ and FM values three specific aerosol types are discriminated corresponding to different aerosol load and optical properties. The aerosol types considered correspond to urban/industrial aerosols, coarse-mode particles and clean maritime conditions. This study focuses on the seasonal and year-to-year fluctuation of the number of occurrences as well as the AOD₅₅₀ and FM values of each aerosol type. The coarse-mode particles are observed mainly in the summer, while spring is the most favorable season for the occurrence of urban/industrial aerosols. On the other hand, clean maritime conditions occur mainly in the winter. The AOD₅₅₀ values for the coarse-mode particles are higher in spring, while the urban/industrial and clean maritime aerosols exhibit slightly higher values in the summer. The seasonal distribution of the aerosol properties is related to anthropogenic and dust emissions in the spring/summer period, but is modified by atmospheric dispersion and precipitation in late autumn/winter. The main conclusion of the study is that the coarse-mode particles exhibit much stronger inter-annual and seasonal variability compared to the urban/industrial aerosols. Finally, three cases corresponding to each aerosol type are analyzed with the aid of synoptic weather maps, air mass trajectories and MODIS data.     

木马盗号案件的侦查取证

木马不仅破坏计算机及计算机网络,而且对其进行控制,并窃取或篡改重要信息,不断对网络安全造成严重的破坏。另外,木马还被许多不法分子用作犯罪工具,造成巨大的经济损失,甚至扰乱社会治安。基于上述情况,对木马盗取网络虚拟财产的研究正受到人们的广泛关注。     

Validation of MODIS derived aerosol optical depth over the Yangtze River Delta in China

MODIS derived aerosol optical depths (AODs) at 550 nm are compared with sunphotometer CE318 measurements at 7 sites located at Yangtze River Delta (YRD) in China from July to October, 2007. The evaluation result indicates that MODIS AODs (Collection 5, C005) are in good agreement with those from CE318 in dense vegetation regions, but show more differences in those regions with complex underlying surface (such as at lake water and urban surface sites). Reasons for these differences are discussed after removing cases with significant errors caused by validation scheme. The final validation result shows that MODIS AODs are in good agreement with CE318 with a correlation coefficient of 0.85 and RMS of 0.15. 90% of MODIS cases fall in the range of Δτ = ± 0.05 ± 0.20τ, indicating MODIS aerosol retrieval algorithm, aerosol models and surface reflectance estimate are generally suitably reasonable for aerosol retrieval in YRD. However, MODIS AODs show a systemic errors with fitted line of y = 0.75x + 0.13, indicating underestimation of AOD when aerosol loadings are high. Aerosol models and surface reflectance estimations are dominant sources of MODIS aerosol retrieval errors.     

Retrieval of microphysical and optical properties in aerosol plumes with hyperspectral imagery: L-APOM method

This paper presents the retrieval method L-APOM which aims at characterizing the microphysical and optical properties of aerosol plumes from hyperspectral images with high spatial resolution. The inversion process is divided into three steps: estimation of the ground reflectance below the plume, characterization of the standard atmosphere (gases and background aerosols) and estimation of the plume aerosols properties. As using spectral information only is not sufficient to insure uniqueness of solutions, original constraints are added by assuming slow spatial variations of particles properties within the plume. The whole inversion process is validated on a large set of simulated images and reveals to remain accurate even in the worst cases of noise: relative estimation errors of aerosol properties remain between 10% and 20% in most cases. L-APOM is applied on a real AVIRIS hyperspectral image of a biomass burning plume for which in situ measurements are available. Retrieved properties appear globally consistent with measurements.     

连续泡沫分离蛋白质

本文以空气-明胶水溶液体系为研究对象，较为详细地考察了通气量、进料流量、进料浓度、进料位置、泡沫高度、溶液pH值等因素对连续泡沫分离明胶过程中明胶富集度变化的影响．