Telescience at the University of California, Berkeley

The University of California at Berkeley (UCB) is a member of a university consortium involved in telescience testbed activities under the sponsorship of NASA. Our Telescience Testbed Project consists of three experiments using flight hardware being developed for the Extreme Ultraviolet Explorer project at UCB's Space Sciences Laboratory. The first one is a teleoperation experiment investigating remote instrument control using a computer network such as the Internet. The second experiment is an effort to develop a system for operation of a network of remote workstations allowing coordinated software development, evaluation, and use by widely dispersed groups. The final experiment concerns simulation as a method to facilitate the concurrent development of instrument hardware and support software. We describe our progress in these areas.     

Journey across the disciplines: a foundation for scientific communication in bioastronomy

As an increasing number of fascinating discoveries within the realm of bioastronomy appear in media headlines, participating scientists continue to pursue ways of insuring the long-term success of the scientific discipline. In an effort to foster cross-disciplinary collaboration, communication, and training for scientists involved in bioastronomy research, a team of scientists and science education professionals have developed a survey to assess (1) the degree to which scientists in bioastronomy define themselves as interdisciplinary scientists, (2) the extent to which scientists identify their needs for professional development opportunities to become more effective interdisciplinary collaborators, and (3) what services and infrastructure the bioastronomy community needs to develop for long-term productive interdisciplinary communication, collaboration, research and training. The results of a survey, distributed at the 2004 Astrobiology Science Conference (held at Moffett Field, CA), serve the bioastronomy science community by providing a sound research baseline that informs decisions and targeted efforts to increase cross-disciplinary communication, gathering information about needed professional development opportunities for scientists, and generating insights for training of the next generation of astrobiologists. Results indicate that members of the community feel that interdisciplinary communication and collaboration can best be supported by (1) increased funding opportunities, (2) scheduled time for collaboration at professional meetings, (3) reduction of concurrent sessions at professional meetings, and (4) creation of professional development opportunities for scientists.     

考虑温度漂移时动力调谐陀螺输入作用的统计学估算

本文提出了由于不稳定的温度场引起漂移时动力调谐陀螺的输入作用－壳体角振荡的评估算法。     

The formation of sulfate and elemental sulfur aerosols under varying laboratory conditions: implications for early earth

The presence of sulfur mass-independent fractionation (S-MIF) in sediments more than 2.45?×?10(9) years old is thought to be evidence for an early anoxic atmosphere. Photolysis of sulfur dioxide (SO(2)) by UV light with λ?相似文献   

Potential climatic impact of organic haze on early Earth

We have explored the direct and indirect radiative effects on climate of organic particles likely to have been present on early Earth by measuring their hygroscopicity and cloud nucleating ability. The early Earth analog aerosol particles were generated via ultraviolet photolysis of an early Earth analog gas mixture, which was designed to mimic possible atmospheric conditions before the rise of oxygen. An analog aerosol for the present-day atmosphere of Saturn's moon Titan was tested for comparison. We exposed the early Earth aerosol to a range of relative humidities (RHs). Water uptake onto the aerosol was observed to occur over the entire RH range tested (RH=80-87%). To translate our measurements of hygroscopicity over a specific range of RHs into their water uptake ability at any RH < 100% and into their ability to act as cloud condensation nuclei (CCN) at RH > 100%, we relied on the hygroscopicity parameter κ, developed by Petters and Kreidenweis. We retrieved κ=0.22?±0.12 for the early Earth aerosol, which indicates that the humidified aerosol (RH < 100 %) could have contributed to a larger antigreenhouse effect on the early Earth atmosphere than previously modeled with dry aerosol. Such effects would have been of significance in regions where the humidity was larger than 50%, because such high humidities are needed for significant amounts of water to be on the aerosol. Additionally, Earth organic aerosol particles could have activated into CCN at reasonable-and even low-water-vapor supersaturations (RH > 100%). In regions where the haze was dominant, it is expected that low particle concentrations, once activated into cloud droplets, would have created short-lived, optically thin clouds. Such clouds, if predominant on early Earth, would have had a lower albedo than clouds today, thereby warming the planet relative to current-day clouds.     

摆振效应对半球谐振陀螺精度的影响

本文研究了非理想壳体谐振子的摆式固有振荡对半球谐振陀螺精度的影响。得到了一些表达式，它们把非理想谐振子固有工作状态的固有频率和振荡衰减系数与其摆式振荡参数联系在一起。     

中国空军的志愿队

空中作战出现有志愿队 ,乃起自西班牙的佛朗哥内战时代 ,当时双方参与作战的飞行员 ,有来自英、美、苏联、德、意、法等国 ,他们参与的动机 ,多少与其本国的政治背景有关。彼此使用不同的机种 ,互相在空中逞强逞勇 ,借机表演一场国际性的空中比武而已 ,反正胜负都是西班牙人自己的事。我国自七七芦沟桥对日抗战之后 ,于翌年春中国空军已成立一志愿队 ,名为十四队 ,直属于航空委员会。当时航委会的主任是钱大钧将军。队部设在汉口公园内 ,队中的飞行员与地勤人员 ,中外国藉皆有 ,队长是美人史密斯( SMITH) ,年近四十 ,机务员是英人司密时 ,…     

Spatially resolved genomic, stable isotopic, and lipid analyses of a modern freshwater microbialite from cuatro ciénegas, Mexico

Abstract Microbialites are biologically mediated carbonate deposits found in diverse environments worldwide. To explore the organisms and processes involved in microbialite formation, this study integrated genomic, lipid, and both organic and inorganic stable isotopic analyses to examine five discrete depth horizons spanning the surface 25?mm of a modern freshwater microbialite from Cuatro Ciénegas, Mexico. Distinct bacterial communities and geochemical signatures were observed in each microbialite layer. Photoautotrophic organisms accounted for approximately 65% of the sequences in the surface community and produced biomass with distinctive lipid biomarker and isotopic (δ(13)C) signatures. This photoautotrophic biomass was efficiently degraded in the deeper layers by heterotrophic organisms, primarily sulfate-reducing proteobacteria. Two spatially distinct zones of carbonate precipitation were observed within the microbialite, with the first zone corresponding to the phototroph-dominated portion of the microbialite and the second zone associated with the presence of sulfate-reducing heterotrophs. The coupling of photoautotrophic production, heterotrophic decomposition, and remineralization of organic matter led to the incorporation of a characteristic biogenic signature into the inorganic CaCO(3) matrix. Overall, spatially resolved multidisciplinary analyses of the microbialite enabled correlations to be made between the distribution of specific organisms, precipitation of carbonate, and preservation of unique lipid and isotopic geochemical signatures. These findings are critical for understanding the formation of modern microbialites and have implications for the interpretation of ancient microbialite records. Key Words: Microbial ecology-Microbe-mineral interactions-Microbial mats-Stromatolites-Genomics. Astrobiology 12, 685-698.