微小卫星星务计算机系统模拟部件可靠性设计

为确保星务计算机系统长期在轨工作的稳定性,针对系统中数模转换器等不同模拟部件的特点,给出相应的可靠性设计方案。在模拟输入通道中采用中位值滤波和递推平均滤波的组合算法,来获取尽可能可靠的输入数据,在模拟输出通道中则采用中值表决电路通用模块实现正确的模拟输出。该方案已在原理样机研制中得到验证和完善。仿真和验证结果表明,本方案在兼顾微小卫星对功耗、质量等苛刻要求的同时,能够很好地满足系统的可靠性要求。     

A map of human genome sequence variation containing 1.42 million single nucleotide polymorphisms

We describe a map of 1.42 million single nucleotide polymorphisms (SNPs) distributed throughout the human genome, providing an average density on available sequence of one SNP every 1.9 kilobases. These SNPs were primarily discovered by two projects: The SNP Consortium and the analysis of clone overlaps by the International Human Genome Sequencing Consortium. The map integrates all publicly available SNPs with described genes and other genomic features. We estimate that 60,000 SNPs fall within exon (coding and untranslated regions), and 85% of exons are within 5 kb of the nearest SNP. Nucleotide diversity varies greatly across the genome, in a manner broadly consistent with a standard population genetic model of human history. This high-density SNP map provides a public resource for defining haplotype variation across the genome, and should help to identify biomedically important genes for diagnosis and therapy.     

Unit responses and interactions at superior colliculus first stage of input reception

Zusammenfassung Durch Stimulation der visuellen corticalen Zone 17 und 18 des Pulvinarnukleus und des tractus opticus wurden Reiz-Potentiale von SC-Neuronen abgeleitet. Die präkonditionierte Stimulation des visuellen corticalen Zone 18 ergab ein konstantes Reiz-Muster.     

Use of a multi-temporal grid method to analyze changes in glacier coverage in the Tibetan Plateau

This paper describes a multi-temporal grid method for quantifying changes in glacier coverage. A multi-temporal grid synthesizes spatial, attribute and process components of glacier information by sequentially combining spatial data from satellite images or maps. It enables us to identify glacier retreat and advance areas in individual grid cells for three or more periods of data sets. Discrepancies among the sequential data sets were detected graphically and numerically, including noise from geo-location error, misclassification, or different interpretation results in various pixel resolutions. Noise was detected and corrected to a large extent by visualization of the synthetic grid. The paper compares the results with that from a common method based on individual data sets, focusing on the Mt. Naimona'Nyi and Mt. Qomolangma regions at the northern slopes of the Himalayas. Results show that the identified noise (e.g. by 2.5 km2 in the Mt. Naimona'Nyi region) is much larger than measurement uncertainty calculated by sensor resolution and co-registration error (e.g. by 0.015 km2 in the Mt. Naimona'Nyi region). After noise removal, we notice that glacier recession clearly accelerates. The multi-temporal grid method results in a better quantification of glacier variation. It shows that glaciers in the Himalayas have both retreated and advanced during the last several decades, with retreat dominating and accelerating. Glaciers on the northern slope of Mt. Qomolangma in the middle Himalayas retreat more extensively and faster than those in the Mt. Naimona'Nyi region in the western Himalayas.