检索结果-南通市图书馆

Is the two-color method Superior to Empirical Equations in Refractive Index Compensation?

Optics and Photonics Journal 2016年第8期6卷 8-13页

作者： Dong Wei Kiyoshi Takamasu Hirokazu Matsumoto Department of Mechanical Engineering Nagaoka University of Technology Nagaoka City Japan Department of Precision Engineering The University of Tokyo Tokyo Japan

The Edlén empirical equations and the two-color method are the commonly used approaches to converting a length measured in air to the corresponding length in vacuum to eliminate the influence of the refractive index of air. However, it is not well known whether the two-color method is superior to empirical equations in refractive index compensation. We investigated the uncertainties of these approaches via numerical calculations of their sensitivity coefficients of environmental parameters. On the basis of a comparison of their uncertainties, we found that in a 0% humidity environment, the two-color method had potential to provide greater measurement accuracy than the empirical equations.

关键词： two-color method Length Measurement Sensitivity Coefficient Uncertainty Empirical Equations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Visualization of MF/Diesel RCCI Combustion Process and Soot Emission

引用

Journal of Thermal Science 2024年第2期33卷 779-792页

作者： HUANG Chen NI Xiao GE Dameng LI Song ZHANG Wanzhi LIU Jinping ZHANG Tingting School of Mechanical and Electronic Engineering Shandong Agricultural UniversityTaian271018China Shandong Provincial Engineering Laboratory of Agricultural Equipment Intelligence Taian271018China Taian Technician Institute Taian271000China Sinotruk Taian Wuyue Special Vehicle Co. Ltd.Taian271000China School of Mechanical Engineering Shaanxi University of TechnologyHanzhong723001China School of Mechanical Engineering Anyang Institute of TechnologyAnyang455000China

Based on the optical engine,the ignition characteristics,combustion process and soot emission characteristics of diesel under different 2-Methylfuran(MF) atmospheres were investigated by high-speed photography and in-cylinder combustion analysis *** results show that at the same main injection timing,the ignition time of reactivity controlled compression ignition(RCCI) combustion mode is earlier than pure diesel combustion,and the ignition point is concentrated near the *** acts as a spark plug to ignite the mixture,but the flame develops slowly in the early stages and the pressure in the cylinder rises *** with pure diesel,RCCI combustion model has smaller peak values of in-cylinder pressure and heat release rate,shorter ignition delay period,earlier combustion phase and shorter combustion *** main spray time at 6℃A BTDC and 12℃A BTDC,with the increase of MF premixing ratio from 0 to 0.75,the peak cylinder pressure decreased by 19.6% and 26% *** addition,with the increase of the MF heat value ratio,the area of KL factor> 1.5 in the combustion chamber decreased and the space integral natural luminescence(SINL) peak value decreased by 48.37%,and the soot formation rate and yield decreased ***,when the MF heat value ratio was too large(75% of the total calorific value),the ignition delay period increased,and misfire occurred at the main injection timing of 0℃A *** RCCI mode of MF/diesel dual fuel has better stability,and better control effect can be obtained at different main inj ection timing.

关键词： 2-methylfuran RCCI visualization two-color method KL factor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of Generalized Cross Validation in Temperature Field Measurement

Application of Generalized Cross Validation in Temperature F...

引用

第一届国际测量仪器与测试自动化学术会议

作者： Zheng Dezhong Zhou Yinghui Jing Nan (Yanshan University Qinhuangdao 066004 China)

＜正＞The measurement method of flame temperature field using the matrix CCD has been developed. However, much unknown noise in flame images would prevent from obtaining temperature information with accuracy. To eliminate the noise, the analysis algorithm uses wavelet demising by soft-threshold. An important parameter for this procedure is threshold. Conventional methods for obtaining the threshold are suitable for uncorrelated noise and require to estimate the variance of noise. For a signal containing unknown noise, the paper presents using Generalized Cross Validation law to get optimal threshold （GCV-threshold）. This procedure does not require prior knowledge of noise level and is proved to be asymptotically optimal. For comparing with different thresholds, an artificial noisy image is processed by universal-threshold, SURE-threshold and GCV-threshold respectively. The results show whether b) observation or signal-to-noise ratio based on mean square error criterion as an objective quality measure, GCV procedure is superior to others. Furthermore, the method is applied in our temperature field measurement system. The results show the accuracy is improved 1.08% around.

关键词： Temperature field measurement two-color method wavelet image denoising GCV law.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：