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41.
Raymond M. Wheeler Gary W. Stutte Cheryl L. Mackowiak Neil C. Yorio John C. Sager William M. Knott 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(5):798-806
Plants can provide a means for removing carbon dioxide (CO2) while generating oxygen (O2) and clean water for life support systems in space. To study this, 20 m2 stands of potato (Solanum tuberosum L.) plants were grown in a large (113 m3 vol.), atmospherically closed chamber. Photosynthetic uptake of CO2 by the stands was detected about 10 DAP (days after planting), after which photosynthetic rates rose rapidly as stand ground cover and total light interception increased. Photosynthetic rates peaked ca. 50 DAP near 45 μmol CO2 m−2 s−1 under 865 μmol m−2 s−1 PPF (average photosynthetic photon flux), and near 35 μmol CO2 m−2 s−1 under 655 μmol m−2 s−1 PPF. Short term changes in PPF caused a linear response in stand photosynthetic rates up to 1100 μmol m−2 s−1 PPF, with a light compensation point of 185 μmol m−2 s−1 PPF. Comparisons of stand photosynthetic rates at different CO2 concentrations showed a classic C3 response, with saturation occurring near 1200 μmol mol−1 CO2 and compensation near 100 μmol mol−1 CO2. In one study, the photoperiod was changed from 12 h light/12 h dark to continuous light at 58 DAP. This caused a decrease in net photosynthetic rates within 48 h and eventual damage (scorching) of upper canopy leaves, suggesting the abrupt change stressed the plants and/or caused feedback effects on photosynthesis. Dark period (night) respiration rates increased during early growth as standing biomass increased and peaked near 9 μmol CO2 m−2 s−1 ca. 50 DAP, after which rates declined gradually with age. Stand transpiration showed a rapid rise with canopy ground cover and peaked ca. 50 DAP near 8.9 L m−2 d−1 under 860 μmol m−2 s−1 PPF and near 6.3 L m−2 d−1 under 650 μmol m−2 s−1 PPF. Based on the best photosynthetic rates from these studies, approximately 25 m2 of potato plants under continuous cultivation would be required to support the CO2 removal and O2 requirements for one person. 相似文献
42.
简要介绍了适配器的性能要求,分析了硬质聚氨酯泡沫的性能指标。通过对聚氨酯发泡原料进行了分类和分析,设计出合理的配方和成型工艺,研究出一种适合适配器的硬质聚氨酯泡沫材料。经试验结果分析,制备的适配器性能稳定可靠。 相似文献
43.
Studies on urine treatment by biological purification using Azolla and UV photocatalytic oxidation 总被引:1,自引:0,他引:1
Xiaofeng Liu Min Chen Zuliang Bian Chung-chu Liu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(5):783-786
The amount of water consumed in space station operations is very large. In order to reduce the amount of water which must be resupplied from Earth, the space station needs to resolve the problems of water supply. For this reason, the recovery, regeneration and utilization of urine of astronauts are of key importance. Many investigations on this subject have been reported. Our research is based on biological absorption and, purification using UV photocatalytic oxidation techniques to achieve comprehensive treatment for urine. In the treatment apparatus we created, the urine solution is used as part of the nutrient solution for the biological components in our bioregenerative life support system. After being absorbed, the nutrients from the urine were then decomposed, metabolized and purified which creates a favorable condition for the follow-up oxidation treatment by UV photocatalytic oxidation. After these two processes, the treated urine solution reached Chinese national standards for drinking water quality (GB5749-1985). 相似文献
44.
Arumugam Senthil Kumar Shiv Prasad Aggarwal Prakash Chauhan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(4):1350-1364
Geo-Spatial Technology and Applications (GSTA) contributes significantly to the implementation of the UN 2030 Agenda for Sustainable Development, which seeks to ‘leave no one behind’. This study attempts to assess the gender diversity in enrolment in GSTA programmes in developing countries in Asia using data available with the UN-affiliated Regional Centre in India. A survey was also conducted to gauge trainees’ comfort in a complex multi-cultural, multi-linguistic classroom environment. The analysis shows that female participation in short-term courses has been increasing rather steeply over the years (1995–2019). The enrolment has reached 30% in recent years. It is also observed that the female participants have preferred (about 10%) to enrol in physical Science and Technology (ST) -oriented courses such as Remote Sensing and GIS, Satellite Meteorology and Climate Change, and Space and Atmospheric Sciences when compared to electrical Engineering and Technology-oriented Satellite Communications and Global Navigation Satellite Systems courses that would require a strong knowledge of digital signals and systems theory.The survey study with a participation of 150 trainees from 17 countries shows that women trainees have a slight edge by 9% over the male counterparts in learning ST elements of the courses. At sub-regional levels, it is observed that participants from Indian sub-continent countries (ISC) are better by 15% than participants from South-east Asian Countries (SAC) and Central Asian Countries (CAC). As far as the course structure perspective is concerned, there has been a significant difference with 70% of the ISC trainees have found the courses as well-balanced covering equally both technology and applications, while only 36% and 56% of the trainees from SAC and CAC, respectively, have found the course as balanced. Importantly, the survey has revealed that the participants from SAC and CAC have a big challenge in apprehending lectures in English, as reflected by their top scores at 18% and 17%, respectively, compared with the corresponding value of the ISC trainees being 72%. Recommendations are suggested to sustain the female enrolment in long-term GSTA training programmes. Strategies that create family-friendly learning conditions, including joint education programmes involving lead institutions of the participants’ countries, are proposed to facilitate higher female participation. Furthermore, measures such as standardisation of curricula regionally at undergraduate levels and having periodic meetings of trainers are recommended in order to minimise the trainees’ core competency gaps in GSTA disciplines at the regional level. 相似文献
45.
基于云计算的资源调度策略 总被引:2,自引:0,他引:2
基于云计算虚拟化技术,提出了一种租借理论和动态多级资源池相结合的资源调度策略,可以有效减少资源空闲时间,提高资源的利用率。根据策略设计了资源调度模型,并搭建实验环境对提出的资源调度策略进行了试验。实验证明该策略确实可以有效的提高资源的利用率。 相似文献
46.
碳纤维树脂基复合材料发展现状及前景展望 总被引:9,自引:1,他引:8
文章较系统地介绍了碳纤维树脂基复合材料的优异性能、产业背景、新技术国际发展趋势、我国产业化发展现状及存在的主要问题,并有针对性地提出对策和建议,可供从事复合材料研究开发的相关人员、产业界人士及有关政府管理部门参考。 相似文献
47.
目前海面风场观测手段有限,基于全球导航卫星系统反射信号处理(global navigation satellite system reflection,GNSS-R)的天基观测为全球风场信息获取提供了全新的手段.GNSS-R海面风速探测技术具有全天时、全天候、低功耗、宽覆盖、多信号源、低成本等特点,日益获得了广泛的关注... 相似文献
48.
49.
由于辐射而在电路的时序逻辑部分和组合逻辑部分产生的逻辑软错误已经逐渐成为阻碍系统可靠性和稳定性的主要威胁。提出了一种结合了基于主/g.1atch设计和改进的时间冗余策略两种技术的容错体系结构,通过ISCAS’89测试基准电路进行验证并对实验结果的分析发现,该容错体系结构获得了很高的容错性能。 相似文献
50.