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X射线衍射仪系统误差校正曲线的研究 被引量:1
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作者 黄佶 韩锡贵 《理化检验(物理分册)》 CAS 1997年第12期14-15,30,共3页
提出了用多个标准样品的X射线衍射角数据共同拟合一条系统误差曲线的方法。并用此方法求得CaCO_3粉末晶体的点阵参数,同理论标准点阵参数值作了相对误差分析,结果表明:在相同测角准确度下,与单标样法相比,用多标法校正后的一组衍射角数... 提出了用多个标准样品的X射线衍射角数据共同拟合一条系统误差曲线的方法。并用此方法求得CaCO_3粉末晶体的点阵参数,同理论标准点阵参数值作了相对误差分析,结果表明:在相同测角准确度下,与单标样法相比,用多标法校正后的一组衍射角数据所求得的点阵参数的相对误差大大降低。 展开更多
关键词 多标样 标样 X射线 衍射角数据 校正曲线
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黄金饰品中金含量X-射线能量色散光谱分析
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作者 李叶农 《测试技术学报》 1996年第3期550-553,共4页
本篇提出X-射线能谱仪测定黄金饰品含金量的方法,此方法采用X-射线能谱仪(ED-XRF)中定量分析软件,选择适当工作条件。测定26个黄金标样中金(Au),并研究饰品形状对金(Au)含量测定影响,结果证明金(Au)含量在98.98%以上样品,分析误差在0.0... 本篇提出X-射线能谱仪测定黄金饰品含金量的方法,此方法采用X-射线能谱仪(ED-XRF)中定量分析软件,选择适当工作条件。测定26个黄金标样中金(Au),并研究饰品形状对金(Au)含量测定影响,结果证明金(Au)含量在98.98%以上样品,分析误差在0.01~0.12%之间,精密度<0.2%,金含量在37.0~98.98%之间的样品,分析误差在0.01~0.17%,精密度<0.3%。在选择适当仪器条件参数下,不同K金饰品形状对Au含量测定无明显影响。 展开更多
关键词 黄金标准样品 M0滤光片 多标样回归软件
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An ecological perspective on Joseph Rock’s(1884-1962)plant collection activities in China
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作者 Jifan Luo Ruozhi Huang +7 位作者 Hai Yan Renwu Wu Shuai Liao Zhoubing Xiang Yongxi Zou Liangchen Shi Ke Wang Zhiyi Bao 《Journal of Plant Ecology》 SCIE 2024年第4期100-113,共14页
In the early 20th century,numerous western botanists,often referred to as‘plant hunters’,embarked on ambitious expeditions to China,playing a crucial role in the study of botany and botanical diversity.Despite their... In the early 20th century,numerous western botanists,often referred to as‘plant hunters’,embarked on ambitious expeditions to China,playing a crucial role in the study of botany and botanical diversity.Despite their contributions,comprehensive assessments of their explorations are lacking.To bridge this gap,this article focuses on the work of Joseph Charles Francis Rock,a notable figure in that era.Our work revisits Rock’s botanical expeditions within the broader context of botanical diversity conservation.It outlines his historical experiences in collecting plants in China and enumerates the species composition and phenotypic traits of the plants he collected.Additionally,it also analyzes the spatial distribution of the species,the completeness of his collection and the α-and β-diversity of the plants he collected.Our findings reveal that Rock led four major botanical expeditions in China between 1922 and 1933,amassing a total of 28184 sheets and 16608 numbers across 204 families,1081 genera and 4231 species.His focus was predominantly on ornamental species,which exhibit a variety of flower colors and inflorescences.His collection work spanned 5 provinces,35 cities and 72 counties,with a notable concentration in the Hengduan Mountains,a current biodiversity hotspot.This study not only reconstructs Rock’s botanical legacy but also offers valuable historical data and fresh analytical insights for understanding contemporary plant diversity.It contributes to the ongoing discourse on the importance of preserving plant diversity as a cornerstone of environmental sustainability. 展开更多
关键词 Joseph Charles Francis Rock plant specimen collection history plant diversity plant collector
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