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就控制测量中广泛应用的红外测距导线这一布设形式所用仪器及观测误差作初步分析 ,讨论如何将误差控制在允许范围内 ,为建筑施工放样阶段提供可靠的精度保证。 相似文献
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杨小平 《杨凌职业技术学院学报》2010,9(1):76-78
GPSRTK技术在测量领域中已得到了广泛应用,但作业方式普遍较为单一,本文主要探讨了RTK测量所具有的多种作业方式,提出了应根据测区已有控制资料情况和测量成果需求的紧迫程度,灵活选用RTK测量的作业方式.通过对全站仪测距精度分析,实际工程中对用全站仪所测距离要进行归化投影改正。 相似文献
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赵振伟 《辽宁科技学院学报》2010,12(1):16-17
文章论述了野外测量中边角后方交会的一种方法,并进行了精度评定和实际应用举例。该方法简捷易行,克服了已知点不通视给测量工作带来的麻烦,在实际工作中具有较好的应用价值。 相似文献
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导线和电缆截面选择原则的探讨 总被引:1,自引:0,他引:1
张明金 《中国现代教育装备》2007,(11):59-61
导线和电缆的选择是工业企业供电网路设计的一个重要组成部分,因此必须要合理地选择导线和电缆。本文从按允许发热条件、电压损失、机械强度及经济电流密度等角度探讨选择导线和电缆的截面方法。 相似文献
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本文采用边长误差形式分析了不同形状土地面积的测算精度问题,得出了在相对等同条件下所观测的界址点其对应的多边形土地面积具有不同的精度,提出了一定的多边形面积精度对边长精度及其界址点观测的精度要求 相似文献
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对传统加常数测定方法与简单测定方法进行了实验比较,发现传统方法只不过是增加多余观测量来提高测量的精度,而一般生产单位使用电磁波测距时只要求其测距精度达到四等,所以一般生产单位完全可以利用简单方法来检查仪器加常数的变化。 相似文献
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陈潮华 《喀什师范学院学报》2006,27(4):52-55
“七”这个数字和维吾尔族人民的日常生活紧密相关。维吾尔民族尚“七”习俗的缘源及其在宗教、文化、社会生活和民间文学等方面都有具体的反映,并且确已渗入到维吾尔人民的日常生活和文学作品中。 相似文献
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通过对统计图形识别的研究,将统计判决与估计应用于统计图形的识别问题中去,从而将其转化为风险最佳假设检验问题,即在一定的风险度下对相关地量的特征作出决策和判决,给出了风险最佳检验的检验方法。 相似文献
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I estimate the effect of being the best in the class in primary school on performance in secondary school. I implement a novel methodology that exploits that some students are the best in the class because better students in the same school are assigned to other classes. If students were randomly assigned, the probability of being the best in the class would be a well-known function of students ranking in the school and the number of classes. I use this exogenous probability as an instrument for actually being the best in the class. I find a positive impact of being the best in the class on future performance: being the best in primary school increases test scores by 0.13 standard deviations in secondary school. My instrument is suitable to account for the sorting of units into groups in other contexts. 相似文献
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本文对地下连续墙设计过程中的钢筋网保护层、钢筋网接头、钢筋网预埋件、墙体锚固深度、槽底清孔等各个环节中影响连续墙质量的一些问题进行了探讨。 相似文献
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朱彤 《重庆职业技术学院学报》2010,19(2):5-7
重庆地区高职教师对培训的总体状况满意度低的原因是很多高职院校并没有制定系统的培训活动规划,没有相关的考核、薪酬和任用制度,也没有对效果及转化的评估。 相似文献
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Objective:To evaluate the accuracy of a scoring system combining zygote and embryo morphology in predicting the outcome of in vitro fertilization(IVF)treatment.Methods:In a study group,117 consecutive IVF or intracytoplasmic sperm injection(ICSI) cycles with embryo transfer were carried out and 312 embryos were scored Using a combmed scoring system(CSS)of zygote and embryo morphology before transplantation.In a control group,a total of 420 IVF or ICSI cycles were carried out and 1176 embryos were scored using a cumulative embryo score(CES).The effects of the combined scoring system on the embryo implantation rate and pregnancy rate per cycle were analyzed.Results:Using the combined scoring system,the embryo implantation rate(27.6%)and the clinical pregnancy rate(48.7%)were significantly higher than those in the control group(20.8%and 38.6%,respectively).Also,the implantation rate of embryos scoring≥70 (38.5%:82 sacs/213 embryos)was significantly higher (P<0.001)than that of embryos scoring<70(4%:4 sacs/99 embryos).The pregnancy rate of patients with embryos scoring≥70 using the combined scoring system(66.7%)Was significantly higher(P<0.001)than that of patients with embryos scoring≥20 using the cumulative embryo score(59.0%).Conclusion:The results suggest that selecting embryos with a high Score(≥70)using the combined scoring system could inerease the implantation rate and pregnancy rate,and that using a scoring system combining assessments of human zygotes and pre-implantation embryos might predict IVF outcomes more accurately than using a cumulafive embryo score. 相似文献