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971.
S.A. Ushakova A.A. Tikhomirov N.A. Tikhomirova Yu.A. Kudenko Yu.A. Litovka O.V. Anishchenko 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The main obstacle to using mineralized human solid and liquid wastes as a source of mineral elements for plants cultivated in bio-technical life support systems (BLSS) is that they contain NaCl. The purpose of this study is to determine whether mineralized human wastes can be used to prepare the nutrient solution for long-duration conveyor cultivation of uneven-aged wheat and Salicornia europaea L. plant community. Human solid and liquid wastes were mineralized by the method of “wet incineration” developed by Yu. Kudenko. They served as a basis for preparing the solutions that were used for conveyor-type cultivation of wheat community represented by 5 age groups, planted with a time interval of 14 days. Wheat was cultivated hydroponically on expanded clay particles. To reduce salt content of the nutrient solution, every two weeks, after wheat was harvested, 12 L of solution was removed from the wheat irrigation tank and used for Salicornia europaea cultivation in water culture in a conveyor mode. The Salicornia community was represented by 2 age groups, planted with a time interval of 14 days. As some portion of the nutrient solution used for wheat cultivation was regularly removed, sodium concentration in the wheat irrigation solution did not exceed 400 mg/L, and mineral elements contained in the removed portion were used for Salicornia cultivation. The experiment lasted 4 months. The total wheat biomass productivity averaged 30.1 g · m−2 · day−1, and the harvest index amounted to 36.8%. The average productivity of Salicornia edible biomass on a dry weight basis was 39.3 g · m−2 · day−1, and its aboveground mass contained at least 20% of NaCl. Thus, the proposed technology of cultivation of wheat and halophyte plant community enables using mineralized human wastes as a basis for preparing nutrient solutions and including NaCl in the mass exchange of the BLSS; moreover, humans are supplied with additional amounts of leafy vegetables. 相似文献
972.
973.
《中国航空学报》2019,32(11):2516-2525
The stress corrosion cracking (SCC) susceptibility of 2297 Al-Li alloy in 1 M NaCl + 0.01 M H2O2 solution (CP solution) and 1 M NaCl + 0.01 M H2O2 + 0.6 M Na2SO4 solution (CPS solution) was investigated by slow-strain rate tests at various strain rates ranging from 10−5 s−1 to 10−7 s−1. The roles of H2O2 and SO42− in the corrosion process were estimated by potentiodynamic polarization and electrochemical impedance spectroscopy. 2297 Al-Li alloy does not fracture ascribed to SCC in CP solution, while it undergoes SCC in CPS solution. In CPS solution, with a decreasing strain rate from 10−5 s−1 to 10−7 s−1, the SCC susceptibility firstly rises and then declines exhibiting a peak value at a strain rate of 10−6 s−1. H2O2 promotes the active dissolution while SO42− lowers the corrosion rate. The SCC fracture is associated with a decline in the dissolution rate of the crack tip by SO42−, which leads to stress concentration. In CPS solution, a reduction in the local dissolution rate of the crack tip leads to stress concentration, resulting in SCC fracture. As the preferred initiation site for a crack, pits also show a noteworthy effect on SCC of 2297 Al-Li alloy. 相似文献
974.
远场涡流检测技术因检测深度深和检测结果可靠性高等诸多优点适合飞机多层金属铆接构件的快速检测。针对飞机铆接件铆钉孔沿边隐藏裂纹的原位检测,建立了多层金属铆接构件隐藏缺陷平面远场涡流检测有限元模型,对激励线圈内径、磁路结构以及屏蔽阻尼进行了仿真优化,研制了激励线圈和检测线圈均带组合屏蔽结构的传感器,采用激励-检测线圈环绕铆钉旋转扫描的方式,研究多层金属铆接构件铆钉孔沿边隐藏裂纹信号特征。仿真与试验结果表明:罐形磁芯聚磁效果是柱形磁芯的1.85倍,采用铝+铜组合屏蔽罩能够将远场区提前10 mm,检测线圈位于缺陷正上方时,检测信号的幅值和相位存在极大值,且极大值随着缺陷埋深的增加逐渐下降,研究成果可望用于指导飞机多层金属铆接构件的工程检测实践。 相似文献
975.
剥蚀是影响老龄飞机结构完整性的重要因素之一。本文对LY12CZ铝合金含孔试件进行了预剥蚀疲劳试验,试验结果表明剥蚀使疲劳寿命下降,但其与剥蚀程度并不成正比。运用MSC.Marc中的单元"软化"技术模拟了剥蚀对试件应力分布影响,结果表明最大主应力不但与腐蚀深度有关,还与腐蚀形貌和位置有关。最后基于材料的初始不连续状态(initial discontinuity state,IDS),建立了评估剥蚀对含孔试件疲劳寿命影响的模型。预测值与试验结果比较表明,该模型预测结果精确,方法可靠。 相似文献
976.
977.
航天器自动化测试语言研究 总被引:1,自引:0,他引:1
航天器测试语言是支撑航天器自动化测试的形式体系及航天器测试过程标准,在当前多航天器批产网络化测试的新需求下,测试语言标准体系研究对于提高航天器测试自动化水平和保障测试过程安全具有重要意义。通过对现有典型航天器测试语言的全面分析和比较,总结出基本特征,并结合当前先进的网络计算技术,提出了我国航天器测试语言发展的目标和方向,同时针对国内航天器测试语言研究设计工作的不足,给出一种航天器测试语言CATOL(China Aerospace Test and Operation Language)。该研究对提高我国航天器测试业务规范水平和测试人员的工作效率、促进航天器测试自动化研究的发展将起到一定的推动作用。 相似文献
978.
979.
文章针对装备全寿命周期风险的特点,对装备全寿命周期风险识别与评估的方法进行了归纳,并具体到装备全寿命周期各阶段,对风险识别方法进行了总结,对装备全寿命周期风险评估的主要方法进行了简单介绍和适用性比较,指出未来风险评估方法的发展趋势,认为综合集成的评估方法可以成为装备全寿命周期风险评估方法研究的一个方向。 相似文献
980.