Bubble detector characterization for space radiation

In light of the importance of the neutron contribution to the dose equivalent received by space workers in the near-Earth radiation environment, there is an increasing need for a personal dosimeter that is passive in nature and able to respond to this neutron field in real time. Recent Canadian technology has led to the development of a bubble detector, which is sensitive to neutrons, but insensitive to low linear energy transfer (LET) radiation. By changing the composition of the bubble detector fluid (or “superheat”), the detectors can be fabricated to respond to different types of radiation. This paper describes a preliminary ground-based research effort to better characterize the bubble detectors of different compositions at various charged-particle accelerator facilities, which are capable of simulating the space radiation field.     

Production of neutrons from interactions of GCR-like particles

In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations.     

不连续刚性机场道面的动力学计算

append介绍了一种不连续刚性机场道面动力学计划的有限元法。这种计算方法考虑了飞机与刚性道面之间的相互动力作用。这种刚性道面模拟成一系列粘弹性基础上不连续的、薄板有限元。由于是不连续的，所以荷载传递装置模拟成垂直的弹簧，而弹簧劲度取地传力杆的特性和传力杆与混凝土的相互作用。粘弹性是由分布的弹簧和减震器组成的。运动的飞机荷载是由线性弹簧和减震支承的块状物体（下称飞机悬浮体）来模拟的。这些飞机荷载有既定的     

德国致力于再入舱试验

再入舱似乎是过去的航天技术,但对大多数国家来说,它仍是难以逾越的科技难题,在新形势下,再入舱实验由于与高新技术紧密相连,而焕发出了新的光彩。     

EVA物体操作技能的特性

通过考察舱外活动（EVA）工作群体的经验教训，本文确诊了熟练进行物体操作的关键属性，并将这些特性转化成可测量的量。我们建告了一个设备，使得精确气浮轴承地析上的舱外机动装置（EMU）的运动自由度（DOF）增大，提高了地面研究对于实际操作的有效性。结果发表了轨道更换单元（ORU）模型与物体操作者之间相互作用的敏感模式，这对在轨道上的高效工作是很重要的。本研究还证实，即使在不十分完善的观测条件下，用各种普通食品也能测量这些模式。     

Pyrite-induced hydrogen peroxide formation as a driving force in the evolution of photosynthetic organisms on an early earth

The remarkable discovery of pyrite-induced hydrogen peroxide (H2O2) provides a key step in the evolution of oxygenic photosynthesis. Here we show that H2O2 can be generated rapidly via a reaction between pyrite and H2O in the absence of dissolved oxygen. The reaction proceeds in the dark, and H2O2 levels increase upon illumination with visible light. Since pyrite was stable in most photic environments prior to the rise of O2 levels, this finding represents an important mechanism for the formation of H2O2 on early Earth.