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Comparative Study on Mineral Elements in the Roots of Rheum tanguticum from Qinghai-Plateau 被引量:2
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作者 LI Jin-ping HAN You-ji +3 位作者 LIU Li-kuan LI Tian-cai SUN Jin CHEN Gui-chen 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2011年第3期812-815,共4页
In the present paper,the authors analysed 10 mineral elements in the roots of Rheum tanguticum collected from 30 different habitats.The mean concentration values of the 10 elements decreased as follows: Ca>Mg>K&... In the present paper,the authors analysed 10 mineral elements in the roots of Rheum tanguticum collected from 30 different habitats.The mean concentration values of the 10 elements decreased as follows: Ca>Mg>K>Fe>Mn>Cr>Zn>Ni>Cu>Se. Ca,Mg,K and Fe were abundant in this herb.Most elements varied over a wide range depending on the different habitats.The mineral element data were evaluated by principal component analysis to reveal the distribution pattern of elements in root.Four principal components(K-Ca factor,Cu factor,Mg factor and Zn-Se factor) of plant elements were selected.The authors' study provided a new scientific foundation for further studies and general application of this Chinese herb. 展开更多
关键词 Rheum tanguticum Maxim.ex Balf mineral elements Principal component analysis(PCA) Different habitats
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Heavy Metal Control in Domestic Rubbish by Source Screening and Suitability of Nutrient Elements as Turfgrass Medium 被引量:7
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作者 DUOLi-an ZHAOShu-lan GAOYu-bao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2005年第1期1-4,共4页
This paper, probing into heavy metal control in domestic rubbish by source screening and nutrient element analysis, revealed the feasibility of source control of heavy metals and the suitability of rubbish as turfgras... This paper, probing into heavy metal control in domestic rubbish by source screening and nutrient element analysis, revealed the feasibility of source control of heavy metals and the suitability of rubbish as turfgrass medium. Heavy metals in domestic rubbish were controlled by source screening before composting. The study consisted of a control with garden soil. The contents of main mineral elements and heavy metals in rubbish compost and control were determined by the method of ICP-AES. The results showed that heavy metal concentrations in rubbish were lower than those in garden soil, and little difference occurred between rubbish and garden soil in main mineral element concentrations. Based on this, it was concluded that rubbish compost was favorable for using as turfgrass medium and heavy metal control in rubbish by source screening was effective. 展开更多
关键词 domestic rubbish compost heavy metal screening control mineral element turfgrass medium
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Machine learning improve the discrimination of raw cotton from different countries
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作者 WANG Tian XU Shuangjiao +4 位作者 WEI Jingyan WANG Ming DU Weidong TIAN Xinquan MA Lei 《Journal of Cotton Research》 2025年第3期444-456,共13页
Background The geo-traceability of cotton is crucial for ensuring the quality and integrity of cotton brands. However, effective methods for achieving this traceability are currently lacking. This study investigates t... Background The geo-traceability of cotton is crucial for ensuring the quality and integrity of cotton brands. However, effective methods for achieving this traceability are currently lacking. This study investigates the potential of explainable machine learning for the geo-traceability of raw cotton.Results The findings indicate that principal component analysis(PCA) exhibits limited effectiveness in tracing cotton origins. In contrast, partial least squares discriminant analysis(PLS-DA) demonstrates superior classification performance, identifying seven discriminating variables: Na, Mn, Ba, Rb, Al, As, and Pb. The use of decision tree(DT), support vector machine(SVM), and random forest(RF) models for origin discrimination yielded accuracies of 90%, 87%, and 97%, respectively. Notably, the light gradient boosting machine(Light GBM) model achieved perfect performance metrics, with accuracy, precision, and recall rate all reaching 100% on the test set. The output of the Light GBM model was further evaluated using the SHapley Additive ex Planation(SHAP) technique, which highlighted differences in the elemental composition of raw cotton from various countries. Specifically, the elements Pb, Ni, Na, Al, As, Ba, and Rb significantly influenced the model's predictions.Conclusion These findings suggest that explainable machine learning techniques can provide insights into the complex relationships between geographic information and raw cotton. Consequently, these methodologies enhances the precision and reliability of geographic traceability for raw cotton. 展开更多
关键词 Raw cotton mineral elements Machine learning Shapley value
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青海尖顶山锶矿床地质特征及成因分析 被引量:4
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作者 陈秉芳 林文山 +5 位作者 白建海 赵海霞 李建亮 任华 白宗海 付军 《西北地质》 CAS CSCD 北大核心 2018年第4期184-193,共10页
尖顶山天青石矿床位于柴达木盆地西北缘,矿体主要产于上新统狮子沟组上段含碳钙质泥岩及灰岩中,呈层状、似层状、透镜状,矿石以原生天青石矿石为主,品位较高,连续性好。含矿砂岩ΣREE值较低,平均为42.73×10^(-6),LREE/HREE平均为6.... 尖顶山天青石矿床位于柴达木盆地西北缘,矿体主要产于上新统狮子沟组上段含碳钙质泥岩及灰岩中,呈层状、似层状、透镜状,矿石以原生天青石矿石为主,品位较高,连续性好。含矿砂岩ΣREE值较低,平均为42.73×10^(-6),LREE/HREE平均为6.48;δEu平均为0.94,δCe平均为0.98;La/Yb-REE图中含矿岩石投点于沉积岩区,显示成矿物源具有多来源性特征;天青石矿的形成可能与深层地下卤水及盆地周缘陆缘碎屑物质富矿流体的补给紧密相关,表明该矿床成因可能具有陆源碎屑化学沉积型特征。 展开更多
关键词 尖顶山 天青石 稀土元素 成矿物源 矿床成因
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多矿物岩石流变性的有限元计算 被引量:3
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作者 杨振涛 宁杰远 赵永红 《岩石学报》 SCIE EI CAS CSCD 北大核心 2004年第6期1469-1476,共8页
本文利用有限元计算方法从单矿物的流变关系式来确定其组合而成的岩石整体的流变规律。建立了三维不可压缩流体的粘弹性有限元模型,计算模型的骨架矿物橄榄石为立方体,填充矿物尖晶石分别取为立方体、单一球体和多个球体,模拟双矿物在... 本文利用有限元计算方法从单矿物的流变关系式来确定其组合而成的岩石整体的流变规律。建立了三维不可压缩流体的粘弹性有限元模型,计算模型的骨架矿物橄榄石为立方体,填充矿物尖晶石分别取为立方体、单一球体和多个球体,模拟双矿物在三轴压缩实验条件下的蠕变变形过程。首先,本文验证了使用有限元方法数值模拟双矿物在三轴压缩实验下的蠕变变形的可行性。其次,计算研究了当填充矿物为弱矿物时几何外形对整体流变强度的影响,结果表明,填充矿物的几何外形为立方体时比球体时对整体的流变强度有更大的影响。当填充矿物体积不同时,随着填充矿物体积的增加,填充矿物对整体流变强度的影响也不断加大。最后利用三维模型得到的双矿物整体的流变强度结果,归纳出了填充矿物尖晶石占体积5%,10%,15%,20%时和骨架矿物橄榄石构成的双矿物岩石的蠕变关系式。与Tullis利用平面应变模型归纳出的双矿物经验流变关系式比较,发现Tullis的经验流变公式存在较大的误差,而本文得到的双矿物蠕变公式与理论结果更好地符合本文结果为研究地幔多矿物岩石流变规律提供了新的途径。 展开更多
关键词 多矿物岩石 尖晶石 橄榄石 有限元 计算模拟
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