V-22通过使用试验与评估

经过二十几年的研发历程,美国海军的使用试验与评估部队最近确认V-22“鱼鹰”倾转旋翼机达到了作战效能和作战适用性要求,海军陆战队也认为该项目基本上接近了可以大批量生产的阶段。美国国防采办委员会很快将对该倾转旋翼机进行评审,如果进展顺利,预计首批12架V-22将在2007年投入使用。     

欧洲制造商竞争美陆军运输机项目

近年来,欧洲飞机制造商频频利用与美国本土制造商联手的方式,竞争美国军方的一些航空装备采购计划,以避开美国武器进口限制,将其产品打入美国军用市场。最近,在美国陆军未来货运飞机(FCA)采购项目的竞争中,两家欧洲飞机制造商又采用了同样的手段。     

The Surface Composition of Ceres

Our understanding of the composition of Ceres is driven by remote sensing of its surface. We review spectral observations of Ceres over wavelengths from the ultraviolet to the radio, as well as non-spectral data such as thermal inertia, photometric properties, radar experiments, and surface variability. We also discuss the closest likely meteorite analogs to Ceres and consider the likelihood that material from Ceres could be delivered to Earth.     

汇聚世界先进制造装备透视行业未来发展趋势——CIMT2011圆满落幕

在北京暖暖的春光中,满载各方赞誉的第十二届中国国际机床展览会(CIMT 2011)圆满落下帷幕。中国国际机床展览会由中国机床工具工业协会主办,自1989年创办至今已经走过了23年历程,成功举办了12届。本届CIMT 2011展会更是取得了空前的成功,展会汇聚了来自全球28个国家和地区的1400多家业界厂商,众多知名企业悉数参展,使用了中国国际展览中心(新馆)全部8个展馆和1个临时馆,展出面积达12万m2。无论展会规模、展商数量、观众人数、展品数量和水平、展会成交额,还是国家领导人及社会各界的关注程度,都创造了历届CIMT展会和全国同类展会之最。     

数控加工技术及应用调查报告

在飞机和发动机的研制生产中,焊接技术已经成为关键工艺方法之一。其进步与发展不仅能减轻飞机和发动机的重量,而且还能为飞机和发动机新的结构设计提供技术上的支持,促进飞机和发动机性能的整体提升。     

特种加工精密制造——本刊总编辑刘柱对话北京市电加工研究所所长杨大勇先生

北京市电加工研究所专业从事精密数控电加工机床制造和精密运动控制技术开发,是一个集科研、开发、生产于一体的高新技术企业。凭借完全掌握产品的核心技术和优质的产品服务过程     

Olivine-respiring bacteria isolated from the rock-ice interface in a lava-tube cave, a Mars analog environment

The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O(2) as an electron acceptor. The optimum growth temperature is ～12-14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O(2) conditions (e.g., 1.6% O(2)). Most likely, microbial oxidation of olivine near pH 7 requires low O(2) to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars.     

复合加工技术及其在航空航天领域的应用——访北京机床研究所副总师盛伯浩先生

[编者按]机床盛会CIMT 2009结束了,但它展示给业内的新技术、新产品却影响深远,展会上各式复合加工机床纷纷亮相.那么此次展会反映了复合加工的哪些趋势?该技术在航空航天领域的应用情况如何?带着这些问题,本刊记者采访了北京机床研究所副总师盛伯浩先生.     

复合材料专用设备与技术调查报告

广泛采用自动化设备是复合材料构件生产发展的趋势,也是提高产品质量和增强质量稳定性的重要手段。为了增强科研机构、厂家和用户之间的沟通和联系,以便更好地推进复合材料专用设备与技术的研发进程,本刊特别设计了本调查,本调查以"复合材料专用设备与技术"为主题,主要调查对象涉及设备制造商、航空企业用户和科研机构。其中,设备制造商包括美国格柏科技,HEATCON复合维修系统公司,西班牙M.TORRES,北京长征中装科技有限公司,法国弗雷斯特里内机床集团等;航空企业用户包括成都飞机工业(集团)有限公司,第一飞机设计研究院,北京航空制造工程研究所,中国空空导弹研究院等;科研机构包括北京航空航天大学,南京航空航天大学,西北工业大学,哈尔滨工业大学等。通过对复合材料专用设备使用情况、用户需求、用户期望、发展趋势等方面进行分析,为设备制造商的生产和用户的选择提供参考。     

Individual Differences in Representational Precision Predict Spatial Working Memory Span

Perhaps the signature feature of working memory is that it is limited. In the same subjects, we used two different retrieval tasks to independently measure two different limits of spatial memory. Precision was measured by asking participants to localize a missing target item among a field of other targets and distracters. Capacity was measured with a similar task where participants identified, rather than localized, a set of remembered targets from within a larger set of identical items. Across participants, the precision of localization was positively correlated with the number of successfully retrieved items. These data suggest that an individual's representational capacity may ultimately be constrained by their ability to form precise representations of space.