Results 31 to 40 of about 4,462 (152)
Constraint optimization of shearer cutting path based on B-spline curve fitting and mayfly algorithm [PDF]
In order to achieve the intelligent height adjustment control of the shearer, the key techniques are the coal-rock interface recognition, cutting path optimization, and shearer height adjustment control.
Cheng CHENG, Hongzhuang WU, Songyong LIU
core +1 more source
Extended Dynamic Nelson-Siegel Model with Human Factor and Its Application in Predicting Exchange Rate [PDF]
, 2016 随着越来越多的发达国家步入人口老龄化社会，学者们愈发关注人口结构与资产价格的关系（如利率和人口结构之间的关系）。依据人口结构变化能够显著影响利率的理论基础，本文从统计模型的角度提出了基于人口因子的动态Nelson-Siegel扩展模型，并对美国、加拿大等几个国家的国债收益率曲线进行建模，比较两模型的样本内拟合的RMSE和MAE及模型在递归预测和滚动预测下的样本外预测能力。与原始动态Nelson-Siegel模型比较，该模型在样本内拟合效果和样本外预测效果均占优于原始模型，且基于人口因子的动态Nelson-
郑桂凤
core
Purification of Z-Ligustilide by AgNO3-Impregnated Silica Gel [PDF]
, 2014 OBJECTIVE To investigate the application of AgNO3-impregnated silica gel in a format of column chromatography for the isolation and purification of Z-ligustilide from the essential oil of Ligusticum chuanxiong Hort..
CHENG, Y, Rong, J, YANG, C, ZHAO, J
core +1 more source
Fushe yanjiu yu fushe gongyi xuebao建立并比较两种剂量率60Co γ射线诱导人淋巴细胞微核的剂量-效应曲线。采用剂量率0.318 9 Gy/min和0.635 0 Gy/min 60Co γ射线照射离体血样，吸收剂量分别为0 Gy、0.25 Gy、0.50 Gy、0.75 Gy、1 Gy、2 Gy、3 Gy、4 Gy、5 Gy，胞质分裂阻断微核法进行淋巴细胞培养，分析并计算微核率及微核细胞率，拟合剂量-效应曲线。结果表明，两种剂量率下微核率均随吸收剂量而增加，拟合的剂量-效应曲线均符合二次多项式模型；剂量率0.635 0 Gy ...
吴 苹, 田 钲鉨, 谢 磊, 李 启杰
doaj +1 more source
Confocal Raman spectroscopy method based on quadratic curve fitting [PDF]
, 2016 Raman spectroscopy plays an improtant role in analytical science because of its unique characteristics, such as non-contact and non-destructive detecting, fewer sample consumption, high sensitivity and other characteristics, and it provides a powerful ...
Cui, Han +4 more
core
Fitting Methods for Plutonium Abundance Analyses Using the Relative Efficiency Scale Technique [PDF]
In order to improve the precision of plutonium isotope abundance analysis by γ-spectrometry，the article fits the relative efficiency scaling curves of 239Pu and 241Pu energy peaks in the energy region of 120-460 keV by studying the principle of relative ...
Hao LÜ +4 more
core +1 more source
Shuitu Baochi Xuebao, 2017 为研究干旱荒漠地区土壤水分特征的变化规律并探讨土壤水分特征曲线拟合模型的适宜性，以古尔班通古特沙漠南缘丘间地为研究对象，应用压力膜仪测定了丘间地剖面各土层（0—150 cm）的土壤水分特征曲线，结合土壤容重、颗粒分布及饱和含水率等性质，分析了丘间地不同土层水分特征和孔隙大小的分布状况，明确了Gardner模型和van Genuchten模型拟合的适用性。结果表明：（1）丘间地剖面砂质土壤释水量伴随吸力呈规律性变化，低吸力段（0～100 kPa）各土层水分特征曲线走势陡直，释水性强；中高吸力段（100～1
董义阳, 赵成义, 班春广
doaj
Shuitu Baochi Xuebao, 2023 研究根-土复合体土-水特征曲线与抗剪强度的关系,可为紫色土埂坎根-土复合体强化机理的揭示与埂坎稳定性的维持提供科学依据。选取三峡库区典型紫色土坡耕地埂坎草本植物根—土复合体为研究对象,结合Hyprop2土壤水分特征曲线测量仪、滤纸法与直剪试验,拟合土-水特征曲线,揭示基质吸力对根-土复合体抗剪强度的影响。结果表明:(1)根-土复合体土-水特征曲线明显分为边界效应区、过渡区与非饱和残余区,3种常用模型(B-C、VG、F-X)中F-X模型拟合该曲线效果最好,根-土复合体饱和含水率、进气吸力 ...
郑文娇 +4 more
doaj
Guangtongxin yanjiu, 2011 针对光时域反射仪（OTDR）测量长距离光缆线路的动态范围受限问题,提出了一种基于双向OTDR测试的长距离光缆线路性能的测试方法,并构建了测试系统。该系统配置两台监测站,从长距离光缆线路两端分别测试,并将得到的测试曲线在监测中心进行拟合,拟合后的测试曲线能够反映该段光缆线路的性能状况。
赵宏波, 赵子岩, 丁健
doaj