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121.
对制冷、空调中的冷却水循环系统在实际运行中经常出现的故障进行了针对性分析,提出了运行管理应注意的技术问题。对冷却水系统的清洗提出了具体的方案,从洗涤剂的浓度、杀菌灭藻剂和缓蚀剂的用量到中和钝化药剂的用量都给出了具体的量,为冷却水系统的正常运行提供了有力的技术支持。 相似文献
122.
P.K. Karmakar M. Maiti S. Sett C.F. Angelis L.A.T. Machado 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
A multi-channel microwave radiometre (make: Radiometrics Corporation) is installed at Instituto Nacional de Pesquisas Espaciais–INPE, Brazil (22°S). The radiometric output of two channels of the radiometer in the form of brightness temperature at 23.834 GHz and 30 GHz, initially, were used to find out the ambient water vapor content and the non-precipitable cloud liquid water content. The necessary algorithm was developed for the purpose. The best results were obtained using the hinge frequency 23.834 GHz and 30 GHz pair having an r.m.s. error of only 2.64. The same methodology was then adopted exploiting 23.034 GHz and 30 GHz pair. In that case the r.m.s. error was 3.42. These results were then compared with those obtained over Kolkata (22°N), India, by using 22.234 GHz and 31.4 GHz radiometric data. This work conclusively suggests the use of a frequency should not be at the water vapor resonance line. Instead, while measuring the vapor content for separation of vapor and cloud liquid, one of them should be a few GHz left or right from the resonance line i.e., at 23.834 GHz and the other one should be around 30 GHz. 相似文献
123.
戴东新 《沈阳航空工业学院学报》2004,21(6):88-90
探索叶芝、乔伊斯两位爱尔兰作家在信仰、创作手法、历史观、爱尔兰民族运动和人生感悟方面的相同点、不同点,供评阅参考。叶芝、乔伊斯不信仰基督教,有各自的哲理,但有相似的历史观——循环论。乔伊斯充分利用象征主义,以荷马《奥德赛》中的人物、故事情节、地点作为意识流小说《尤利西斯》的框架——各章的题目,揭示了深奥的道理。叶芝参加爱尔兰民族的解放运动,成为爱尔兰文艺的领导人,而乔伊斯却放逐自己于海外,拯救自己的理想——文学。两人在创作中得出各自的结论,以劝谏他人。 相似文献
124.
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
125.
星载可移动多馈源单口径多波束天线研究 总被引:1,自引:1,他引:0
针对我国通信业务容量提升以及热点区域动态变化的保障能力需求,设计了Ka频段多馈源单口径可移动多波束天线,研究了波束馈源簇形成方式、相邻波束馈源交叠方案、天线转动方式、波束形成网络,以实现覆盖区域的高增益通信和波束灵活调整。通过高增益低旁瓣多波束天线的频率复用设计和波束形成网络技术研究,提升卫星通信系统的容量及天线覆盖的灵活性。重点改善波束扫描后的形状畸变和性能恶化问题,仿真表明,对波束幅相权值的优化可以保证天线转动前后波束增益和C/I性能稳定。 相似文献
126.
针对航行体入水冲击过程中的流固耦合问题,利用任意拉格朗日 欧拉算法建立三维入水冲击数值仿真模型。首先,建立球体入水冲击数值模型,获取了入水过程中的冲击载荷和表面压力数据,通过与试验对比,探究网格密度、接触刚度耦合系数以及时间步长对仿真准确性的影响。结果发现,冲击区域网格密度和接触刚度耦合系数决定流固耦合接触刚度;冲击域的网状密度对冲击系数结果和入水速度变化有明显影响;耦合节点之间的接触刚度系数会影响局部压力峰值。最后,建立锥形头部圆柱体入水仿真模型,提出分段刚体计算截面载荷方法,研究不同速度下结构入水冲击加速度、速度、位移和截面载荷变化规律,与试验结果对比证明仿真准确性。 相似文献
127.
Jiansheng Yu Kai Tan Caihong Zhang Bin Zhao Dongzhen Wang Qi Li 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(2):840-856
A total of more than 260 continuous stations and 2000 campaign stations from the Crustal Movement Observation Network of China (CMONOC) project, covering the Chinese mainland and its surrounding areas during the period of 1998–2018, are processed using the Bernese Global Navigation Satellite System (GNSS) software via a state-of-the-art method. We obtain the coordinate time series of all the stations given in the reference frame ITRF2014, estimate the coseismic deformation, and remove outliers. Lastly, we present the latest, most complete, and most accurate contemporary horizontal velocity field with respect to the stable Eurasian plate, irrespective of the postseismic deformations. This study shows that the signal of tectonic movement in Western China is stronger than that in Eastern China particularly in the Tibetan Plateau, with a rate of 18–32?mm/a. Moreover, the signal decays sharply from south to north. However, North China and South China move coherently to the ESE direction mostly at a rate of 4–10?mm/a and have not experienced any abrupt velocity gradients in their interiors. Meanwhile, Northeast China has the lowest velocity of only 2–4?mm/a in addition to the coastal areas that have slightly larger velocities. The densified and continuous observation of GNSS stations are of great significance to the study of the present-day crustal movement and tectonic deformation characteristics of the Chinese mainland. This would help to provide better constraints on the kinematics and dynamics of the region. 相似文献
128.
129.
本文介绍载体作圆锥运动时,由捷联数值运算所造成的惯性基准的偏移。文中推导了刚体绕自身坐标系转动时变换矩阵的四种形式。对转动的不可交换性也通过刚体姿态角作出了描述。 相似文献
130.
飞行员在驾驶飞机的过程中需要用到大量的信息,对信息进行合理的编码可以提高驾驶安全性.根据研究的需要,开发一个用于工效实验的作业任务模型.通过测量被试完成作业任务的正确率和反应时间,结合眼动仪测得的眼动数据,分析文字和位置编码对信息辨识的影响,为显示界面适人性设计提供科学依据.实验结果表明:人对文字信息的辨识受到位置编码影响,位置编码方式与视野范围和注意力分配策略相关;中心位置的辨识效率优于边缘位置,左侧位置优于右侧位置;中文信息的辨识效果优于英文信息,实际应用时应考虑母语的影响. 相似文献