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精密定位软件研制与应用 总被引:1,自引:0,他引:1
介绍了GPS精密静态定位软件LTW_BS的改正模型、预处理和解算模型,及其对2年上海CORS网的数据以及江苏CORS网70个站的数据处理情况.结果表明,计算结果正确,软件运行稳定可靠.对于基线长度100 km区域网静态定位精度能够达到mm级,对于上千km的大区域定位精度优于2cm. 相似文献
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"两课"是马克思主义理论课和思想品德课的简称,进入21世纪,"两课"教学在改革中应该坚持以人为本、以平等的身份和学生交流、理论联系实践、"精"和"管用"和多种教学形式相结合的原则。 相似文献
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定轴旋转弹性梁的固有频率计算 总被引:2,自引:1,他引:1
陈宁 《南京林业大学学报(自然科学版)》2001,25(5):45-48
利用状态方程、指数矩阵2^N算法和求原函数方法,给出一种在水平面内作定轴转动的弹性梁的固有振动频率计算方法。该算法计算精度高,并可推广用于计算和分析有轴力影响的变截面弹性梁的振动。计算结果显示梁端质量对弹性梁各阶固有频率的刚化有不同影响。 相似文献
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Jihua Liu Zhigang Li Xuhai Yang Jikun Ou Shiming Zhong Baoqi Sun Jiasong Wang Yao Kong Zhanke He 《科学通报(英文版)》2014,59(21):2568-2573
For precise orbit determination of geosynchronous earth orbit(GEO)satellites using transfer ranging observations,it is generally assumed that the variation of the satellite transponder delay is very small and that it can be solved as a constant parameter together with satellite orbit parameters.However,this assumption is too general and it reduces the accuracy of orbit determination for GEO satellites.To study and analyse the impact of the satellite transponder delay on GEO satellites orbit determination,two schemes were proposed.First,the satellite transponder delay was eliminated by forming single-difference observations between two ground stations;second,the satellite transponder delay was described as a constant parameter.The preliminary results demonstrate a difference of about1–2 m between the two schemes when used for precise orbit determination of GEO satellites.By fixing the GEO satellite orbit and other relevant parameters estimated by single-difference model,we inversed the instantaneous transponder delay from non-difference observation.It was found that the satellite transponder delay has a distinct diurnal variation,with an amplitude of 3–4 m.The findings of this paper are helpful in establishing an accurate model of satellite transponder delay and in improving the accuracy of GEO satellites orbit determinations and predictions. 相似文献
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万珍平;汤勇 《华南理工大学学报(自然科学版)》2010,38(1)
各种功能玻璃在高技术领域中获得了广泛应用。但功能玻璃大都硬度高、脆性大,易在已加工表面产生裂纹和凹坑。基于大刃倾角刀具的玻璃切削是一种新的加工方法,该方法能在亚毫米级的切削深度下高效地获得无裂纹和凹坑的完整表面。研究了大刃倾角刀具切削玻璃的机理及刀具参数和切削用量对已加工表面质量的影响。研究结果表明,大刃倾角刀具切削玻璃时,表面粗糙度Ra达0.21μm,表面完整性优于传统的玻璃精磨时的表面;要获得较好的已加工表面质量,刀具参数和切削用量都存在一个较佳的取值范围。 相似文献