检索结果-南通市图书馆

Intelligent Identification of Remnant Ridge Edges in Region West of Yongxing Island,South China Sea

Journal of Ocean University of China 2018年第1期17卷 118-128页

作者： WANG Weiwei guo jing CAI Guanqiang WANG Dawei College of Information and Control Engineering China University of PetroleumQingdao 266580China Guangzhou Marine Geological Survey Guangzhou 510760China Laboratory of Marine Geophysics&Geo-Resources Institute of Deep-Sea Science and EngineeringChinese Academy of SciencesSanya 572000China

Edge detection enables identification of geomorphologic unit boundaries and thus assists with geomorphical mapping. In this paper, an intelligent edge identification method is proposed and image processing techniques are applied to multi-beam bathymetry data. To accomplish this, a color image is generated by the bathymetry, and a weighted method is used to convert the color image to a gray image. As the quality of the image has a significant influence on edge detection, different filter methods are applied to the gray image for de-noising. The peak signal-to-noise ratio and mean square error are calculated to evaluate which filter method is most appropriate for depth image filtering and the edge is subsequently detected using an image binarization method. Traditional image binarization methods cannot manage the complicated uneven seafloor, and therefore a binarization method is proposed that is based on the difference between image pixel values; the appropriate threshold for image binarization is estimated according to the probability distribution of pixel value differences between two adjacent pixels in horizontal and vertical directions, respectively. Finally, an eight-neighborhood frame is adopted to thin the binary image, connect the intermittent edge, and implement contour extraction. Experimental results show that the method described here can recognize the main boundaries of geomorphologic units. In addition, the proposed automatic edge identification method avoids use of subjective judgment, and reduces time and labor costs.

关键词： geomorphology mapping edge detection image processing

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

Characteristics of Deoxidation and Desulfurization during LF Refining Al-killed Steel by Highly Basic and Low Oxidizing Slag

引用

Journal of Iron and Steel Research International 2014年第2期21卷 166-173页

作者： jing guo Shu-sen CHENG Zi-jian CHENG State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological EngineeringUniversity of Science and Technology of Beijing Jiuquan Iron and Steel (Group) Co. Ltd.

Steel and slag samples were taken at the start and the end of LF refining for steel plate cold common （SPCC）, in the compact strip production （CSP） process, and at the same time, the temperature and oxygen activity a[o] were measured by using an oxygen sensor. Furthermore, inclusions in steel samples were monitored by scanning electron microscopy （SEM） combined with energy dispersive spectroscopy （EDS）. It was confirmed that a [o] in liq- uid steel was in equilibrium with inclusion rather than with top slag during LF refining. Desulfurization was related to deoxidation since a[o] at slag-steel interface was clarified to be very close to that in liquid steel under the specific con- dition in LF with intense stirring by argon blowing and refined by highly basic low oxidizing slag for Al-killed steel. Sulfur partition ratio （Ls） was very sensitive to a[o]. Since a[o] increased rapidly with temperature rise, it not only offset promotion to desulfurization reaction with temperature rise but decreased Ls. For Al-killed steel, ***- tion of Al2O3 for lowering the activity of Al2O3 in inclusion was believed to be favorable for both deoxidation and desulfurization during LF refining.

关键词： deoxidation desulfurization inclusion sulfur partition ratio LF refining

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

Correlation between superheated liquid fragility and potential energy landscape in Gd-and Pr-based glass-forming alloys

引用

Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 387-393页

作者： guo jing BIAN XiuFang LI XueLian WANG CaiDong Key Laboratory of Liquid Structure and Heredity of Materials Ministry of EducationShandong UniversityJinan 250061China

The kinetic viscosities of superheated liquids on the Gd-based bulk glass-forming alloys are measured by an oscillating viscometer in a high vacuum atmosphere. According to the viscosity data,the parameters of superheated liquid fragility,M,are calculated. Based on the values of M in Gd-and Pr-based (cited from the lit-erature) glass-forming alloys,we find that there is a linear correlation between M and the absolute value of mixing enthalpy,|ΔHmix|,in an alloy system with the same base element,and the larger M,the smaller |ΔHmix|. The alloy with larger M exhibits the larger height of energy barriers separating the minima on the potential energy landscape.

关键词： glass-forming alloy superheated liquid fragility potential energy landscape

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 an Error Statistics Estimation Method to the PSAS Forecast Error Covariance Model

引用

Advances in Atmospheric Sciences 2006年第1期23卷 33-44页

作者： Runhua YANG jing guo Lars Peter RIISHФJGAARD Science Systems and Applications Inc. Lanham USA Science Applications International Corporation Beltsville USA Joint Center for Earth Systems Technology/UMBC Baltimore USA Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt USA

In atmospheric data assimilation systems, the forecast error covariance model is an important component. However, the paralneters required by a forecast error covariance model are difficult to obtain due to the absence of the truth. This study applies an error statistics estimation method to the Pfiysical-space Statistical Analysis System （PSAS） height-wind forecast error covariance model. This method consists of two components： the first component computes the error statistics by using the National Meteorological Center （NMC） method, which is a lagged-forecast difference approach, within the framework of the PSAS height-wind forecast error covariance model; the second obtains a calibration formula to rescale the error standard deviations provided by the NMC method. The calibration is against the error statistics estimated by using a maximum-likelihood estimation （MLE） with rawindsonde height observed-minus-forecast residuals. A complete set of formulas for estimating the error statistics and for the calibration is applied to a one-month-long dataset generated by a general circulation model of the Global Model and Assimilation Office （GMAO）, NASA. There is a clear constant relationship between the error statistics estimates of the NMC-method and MLE. The final product provides a full set of 6-hour error statistics required by the PSAS height-wind forecast error covariance model over the globe. The features of these error statistics are examined and discussed.

关键词： forecast error statistics estimation data analysis forecast error covariance model

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

Theoretical Study of Electronic Structures and Charge Transport Properties of 9,10-Bis（（E）-2-（pyrid-n-yl） vinyl）（n=2, 3, 4） Anthracene

引用

Chinese Journal of Chemistry 2015年第8期33卷 974-980页

作者： Qing guo Lijuan Wang Yuanfei Jiang jing guo Bin Xu Wenjing Tian State Key Laboratory of Supramolecular Structure and Materials Jilin University Changchun Jilin 130012 China School of Materials Science and Engineering Harbin Institute of Technology at Weihai Weihai Shandong 264209 China Institution of Atomic and Molecular Physics Jilin University Changchun Jilin 130012 China

Charge carrier mobility is one of the most significant properties for organic semiconductors. In this work, the electronic structures and charge transport properties of 9,10-bis（（E）-2-（pyrid-n-yl）vinyl）（n=2, 3, 4） anthracene （BP2VA, BP3VA and BP4VA） were investigated via the analysis of the molecular geometry, the reorganization en- ergy, the frontier orbital and density of state, as well as the electronic coupling and the charge mobility. The results indicated that the linkage between 9,10-divinyl anthracene unit and pyridine （ortho-, meta- and para-） influenced not only the intra-molecular conformation （i.e., the reorganization energies）, but also the intermolecular interaction （i.e., transfer integrals）, and finally the charge mobility of the molecules. It is also found that：（1） The calculated charge mobilties of holes are dozens of times higher than those of electrons for the three molecules. （2） The charge mobilities of hole and electron of the three molecules display the trend： μBP4VA〉μBPZVA〉μBP3VA, and the hole mobility of BP4VA is as high as as-cm^2/（V·s）.

关键词： charge mobility reorganization energy electronic structure

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

Inclusion Composition Control During LF Refining for SPCC Using FactSage Combined With Industrial Trials

引用

Journal of Iron and Steel Research International 2013年第2期20卷 14-20页

作者： CHENG Zi-jian guo jing CHENG Shu-sen State Key Laboratory of Advanced Metallurgy School of Metallurgy and Ecology Engineering University of Science and Technology Beijing Hongxing Iron and Steel Co Ltd

Steel plate cold common （SPCC） is a Al-killed steel with Ca-treatment. The control of Al2O3 inclusion into low melting point liquid region is beneficial for inclusion removal, cast-ability promotion and defects reduction during rolling. Thus it is essential to understand steel-inclusion equilibrium since inclusion composition is determined by composition of liquid steel directly through steel-inclusion reaction. Thermodynamic calculation software FactSage is performed to understand how to control inclusion composition during ladle furnace （LF） refining, and industrial trials are carried out to verify calculated results. Firstly, target region for controlling CaO-Al2O3-MgO ternary inclusion is analyzed on the basis of the ternary phase diagram and the relationship between activities related to pure solid and activities related to pure liquid was fixed by thermodynamic analysis in order to obtain reliable activities for components of inclusions in the target region by FactSage. In addition, inclusions in steel samples are detected by scanning electron microscopy （SEM） combined with energy dispersive spectroscopy （EDS）. It is found that most of Al2O3 inclusions are modified into lower melting point region but a number of them are still located in high melting point region at the end of LF refining after Ca-treatment. Moreover, the composition of liquid steel equilibrating with liquid CaO-Al2O3-MgO inclusion is obtained by steel-inclusion equilibrium calculation when w[Al]s is approximating 0.03% as： a[O] is 1.0×10-6 to 4.0×10-6, w[Ca] is 20×10-6 to 50×10-6 and w[Mg] is 0.1×10-6 to 3.0×10-6. At last, stability diagrams of various calcium aluminates and CaS are established and they show that liquid calcium aluminate inclusions form when w[Ca] is more than 20×10-6, but CaS precipitation is difficult to prevent because sufficiently low w[S] （〈0.003%） is required.

关键词： LF refining inclusion control steel-inclusion equilibrium FactSage

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

Extraction study of rare earth elements with N,N'-dibutyl–N,N'-di(1-methylheptyl)-diglycolamide from hydrochloric acid

引用

Nuclear Science and Techniques 2016年第3期27卷 186-193页

作者： guo-jing Sun Jin-Hong Yang Hong-Xiao Yang guo-Xin Sun Yu Cui School of Chemistry and Chemical Engineering University of Jinan

A novel,unsymmetrical diglycolamide,N,N'-dibutyl-N,N'-di(1-methylheptyl)-diglycolamide(DBD1MHDGA),was *** extraction of rare earth elements(REEs) from a hydrochloric acid medium with DBD1 MHDGA was *** results of the extraction experiments indicated that the distribution ratios of RE(Ⅲ) ions increase with an increase in HC1 concentration,atomic number,and extractant *** calculated thermodynamic data show that the extraction process is an exothermic *** organic phase loaded rare earth ions were characterized by infrared *** composition of the extracted complex was determined.

关键词：稀土元素盐酸介质萃取剂庚基红外光谱表征盐酸浓度稀土离子分配比例

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

Chiral Separation of Spiro-compounds and Determination Configuration

引用

Chemical Research in Chinese Universities 2008年第4期24卷 441-444页

作者： LIANG Ya guo jing-jing LIU Xiu-ming WEI Rong-bao School of Chemistry ＆ Chemical Engineering Tianjin University of Technology Tianjin 300191 P.R. China

Chiral spirocyclic compounds have attracted the attention of scholars and scientists owing to their potential applications in the pharmaceutical industry as either active pharmaceutical ingredients, catalysts in synthesizing active enantiomers, or as surface modifiers on silica particles to resolve entantiomers. In this study, five spiro compounds of 3,9-diphenyl-2,4,8,10-tetraoxaspiro[5.5]-undecane（1）, 3,9-（4-methoxyphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（2）, 3,9-（4-methylphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（3）, 4,4＇-（2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl）dibenzoic acid（4） and 3,9-di（4-formyl-phenyl）-2,4,8,10-tetraoxa-spiro[5.5]-undecane（5） were synthesized by grinding pentaerythritol with benzaldehyde, 4-methoxybenzaldehyde, 4-methylbenzaldehyde, 4-carboxybenzaldehyde or terephthalaldehyde monoacetal in the presence of InI3r3 under solvent-free conditions. A normal phase HPLC method was successfully developed to resolve entantiomers of compounds 1--5 on a chiral column. Specific optical rotation of R or S entantiomers（1） was determined and the corresponding configurations were proposed based on Lowe＇s rule.

关键词： Chiral separation Spiro-compounds Optical rotation

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

Impacts of inter-satellite links on the ECOM model performance for BDS-3 MEO satellites

引用

Satellite Navigation 2024年第1期5卷 140-154页

作者： Chao Yang jing guo Xiaolong Xu Longyu Wang Qile Zhao GNSS Research Center Wuhan UniversityNo.129 Luoyu RoadWuhan430079China

Inter-satellite link(ISL)plays an essential role in current and future Global Navigation Satellite System(GNSS).In this study,we investigate the impact of ISL observations on precise orbit determination for BeiDou-3 Navigation Satellite System(BDS-3)Medium Earth Orbit(MEO)satellites based on different Extended CODE Orbit Models(ECOM).Thanks to the better observation geometry of the Ka-band ISL data compared to the L-band data for BDS-3 MEO satellites,the ISL solution substantially reduces Orbit Boundary Discontinuity(OBD)errors,except for C30,which suffers from unstable Ka-band hardware *** the external quality analysis,ISL significantly enhances the reliability of the orbit of MEO satellites manufactured by the China Academy of Space Technology(CAST).The standard deviation(STD)of the satellite laser ranging(SLR)residuals is approximately 2.5 cm,and the root mean square(RMS)is reduced by 10–23%compared to L-band ***,the Sun-elongation angle dependent systematic error in SLR residuals nearly vanishes based on the reduced 5-parameter ECOM(ECOM1)or extended 7-parameter ECOM(ECOM2)with ISL *** is because the ISL reduces the correlation between state parameters and solar radiation pressure(SRP)parameters as well as those among SRP parameters,leading to a more accurate estimation of both orbit and SRP perturbations,particularly those along B *** confirms that the deficiency of the SRP models for BDS-3 CAST satellites can be compensated by using better observation geometry from ISL *** the other hand,for the satellite manufactured by Shanghai Engineering Center for Microsatellites(SECM),the ISL allows for a more accurate estimation of the Bc_(1)parameter in the ECOM1 *** only reduces linear systematic error,possibly because the impact generated by the satellite bus cannot be entirely absorbed by the B-direction parameters.

关键词： BDS-3 MEO Inter-satellite link Solar radiation pressure ECOM

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

Applications of high-gravity technologies in gas purifications: A review

引用

Chinese Journal of Chemical Engineering 2019年第6期27卷 1361-1373页

作者： jing guo Weizhou Jiao Guisheng Qi Zhiguo Yuan Youzhi Liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering School of Chemical Engineering and TechnologyNorth University of ChinaTaiyuan 030051China National Demonstration Center for Experimental Comprehensive Chemical Engineering Education North University of ChinaChina

The traditional gas purification techniques such as wet gas desulfurization, with their advantages of large-scale implementation and maturity, have still been widely used. However, the main drawback of these techniques is the low transfer efficiency, which normally needs towers as tall as tens of meters to remove the pollutants. Therefore, new technologies which could enhance the mass transfer efficiency and are less energy-intensive are highly desirable. As a process intensification technology, high-gravity technology, which is carried out in a rotating packed bed(RPB), has recently demonstrated great potential for industrial applications due to its high mass transfer efficiency, energy-saving, and smaller volume. This consequently provides higher efficiency in toxic gas removal, and can significantly reduce the investment and operation costs. In this review, the mechanism,characteristics, recent developments, and the industry applications of high-gravity technologies in gas purifications, such as hydrogen sulfide, nitrogen oxide, carbon dioxide, sulfur dioxide, volatile organic compounds and nanoparticle removal are discussed, most of the demonstration projects and practical application examples in gas purification come from China. The perspective and prospective of this technology in gas purification and other fields are also briefly discussed.

关键词： High gravity technology Rotating packed bed(RPB) Gas purification Desulfurization Pollution

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

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

在线全文

在线全文

在线全文

在线全文

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

在线全文

在线全文

在线全文

在线全文

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：