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改进的内标准法 被引量:1
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作者 吴学周 余葵芳 姜国华 《现代计量测试》 1997年第2期37-41,56,共6页
内标法是液体闪烁计数法中一种常用的相对测量方法。本文提出一种改进的内标准法,它克服了一般内标准法的一些缺点,减少了测量结果的不确定度。
关键词 内标准法 液体 闪烁计数
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用液闪直接测量核设施周围环境中的氚 被引量:5
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作者 李晓芸 潘竞舜 +3 位作者 娄海林 徐旭涛 赵洋 文富平 《辐射防护》 CAS CSCD 北大核心 2019年第2期111-117,共7页
某些核设施运行时会释放氚,从而引起周围环境中氚活度浓度水平的变化。对核设施周边区域空气、地下水、雨水和海水样品中的氚分别用内标准法(简称"内标法")和外标准淬灭指示参数法(简称"外标法")进行了液闪测量。... 某些核设施运行时会释放氚,从而引起周围环境中氚活度浓度水平的变化。对核设施周边区域空气、地下水、雨水和海水样品中的氚分别用内标准法(简称"内标法")和外标准淬灭指示参数法(简称"外标法")进行了液闪测量。两种标准方法测量数据的相对偏差在-4.0%~4.0%。根据内标法的探测效率与仪器给出的淬灭指示参数制作了4种环境水样的淬灭校正曲线。在环境样品测量中,内标法和外标法的探测效率最大差值约为1.6%,痕量^(14)C和其它β放射性核素对~3H的计数率影响可忽略。对探测效率为21.5%~24.5%无严重淬灭的样品,用液闪直接测量并根据外标法的淬灭校正曲线计算氚活度浓度,相对偏差在-6.35%~4.41%,基本可满足核设施氚常规监测的要求。 展开更多
关键词 液闪测量 内标准法 淬灭校正曲线 核设施
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Research on the Arc Interpolation for the Nonstandard Section Curve of the Piston 被引量:2
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作者 秦月霞 胡德金 《Journal of Donghua University(English Edition)》 EI CAS 2004年第4期95-97,共3页
The transverse section of piston skirt is not a standard circle and is with high precision. So the section curve should be interpolated through the high accuracy method of circular arc interpolation before NC machinin... The transverse section of piston skirt is not a standard circle and is with high precision. So the section curve should be interpolated through the high accuracy method of circular arc interpolation before NC machining. In order to smooth the connection of adjacent arcs and shorten the NC machining program, an interpolation method based on Chebyshev theory of function approximation is proposed here. According to the analysis of the interpolation error, the algorithm is simple and with high precision. By this way the fewest interpolating circular arc segments can be got, and the manufacture requirement is satisfied with the circular arc interpolating curves. 展开更多
关键词 PISTON arc interpolation ellipse curve
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Methods for Setting up a Three-Dimensional Industrial Surveying System of “Building Blocks Type”
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作者 FENGWenhao 《Geo-Spatial Information Science》 2004年第3期157-161,共5页
This paper is to advance some relevant techniques to set up a three-dimensional industrial surveying system of “building blocks type”, making use of the electronic theodolite, standard ruler and portable computer.
关键词 three-dimensional industrial surveying system initial direction innertarget collimator method standard ruler accuracy
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Dynamic thermal management by greedy scheduling algorithm
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作者 QU Shuang-xi ZHANG Min-xuan +1 位作者 LIU Guang-hui LIU Tao 《Journal of Central South University》 SCIE EI CAS 2012年第1期193-199,共7页
Chip multiprocessors(CMPs) allow thread level parallelism,thus increasing performance.However,this comes with the cost of temperature problem.CMPs require more power,creating non uniform power map and hotspots.Aiming ... Chip multiprocessors(CMPs) allow thread level parallelism,thus increasing performance.However,this comes with the cost of temperature problem.CMPs require more power,creating non uniform power map and hotspots.Aiming at this problem,a thread scheduling algorithm,the greedy scheduling algorithm,was proposed to reduce the thermal emergencies and to improve the throughput.The greedy scheduling algorithm was implemented in the Linux kernel on Intel's Quad-Core system.The experimental results show that the greedy scheduling algorithm can reduce 9.6%-78.5% of the hardware dynamic thermal management(DTM) in various combinations of workloads,and has an average of 5.2% and up to 9.7% throughput higher than the Linux standard scheduler. 展开更多
关键词 greedy scheduling algorithm chip multiprocessor thermal-aware
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Building towards a standardised approach to biocorrosion studies: a review of factors influencing Mg corrosion in vitro pertinent to in vivo corrosion 被引量:3
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作者 Sean Johnston Matthew Dargusch Andrej Atrens 《Science China Materials》 SCIE EI CSCD 2018年第4期475-500,共26页
The factors that influence magnesium(Mg)corrosion in vitro are systematically evaluated from a review of the relevant literature. We analysed the influence of the following factors on Mg biocorrosion in vitro:(i)... The factors that influence magnesium(Mg)corrosion in vitro are systematically evaluated from a review of the relevant literature. We analysed the influence of the following factors on Mg biocorrosion in vitro:(i) inorganic ions,including both anions and cations,(ii) organic components such as proteins, amino acids and vitamins, and(iii) experimental parameters such as temperature, p H, buffer system and flow rate. Considerations and recommendations towards a standardised approach to in vitro biocorrosion testing are given. Several potential simulated body fluids are recommended. Implementing a standardised approach to experimental parameters has the potential to significantly reduce variability between in vitro biocorrosion tests, and to help build towards a methodology that accurately and consistently mimics in vivo corrosion. However, there are also knowledge gaps with regard to how best to characterise the in vivo environment and corrosion mechanism. The assumption that blood plasma is the correct bodily fluid upon which to base in vitro methodologies is examined, and factors that influence the corrosion mechanism in vivo, such as specimen encapsulation, bear consideration for further studies. 展开更多
关键词 CORROSION BIOCORROSION MAGNESIUM biodegradable metals in vitro in vivo
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