检索结果-南通市图书馆

Feasibility of measuring moisture content of green sand by a low frequency multiprobe detector based on dielectric characteristics

引用

China Foundry 2023年第3期20卷 197-206页

作者： De-quan Shi Gui-li Gao Ming Sun Ya-xin Huang School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China School of Materials Science&Chemical Engineering Harbin University of Science and TechnologyHarbin 150040China

Green sand is a mixture of silica sand,bentonite,water and coal powder,and other additives.moisture content is an important index to characterize the properties of green sand.Based on the dielectric characteristics of green sand and transmission line theory,a method for rapidly measuring the moisture content of green sand by means of a low frequency multiprobe detector was proposed.A system was constructed,where six detectors with different arrangements and probes were designed.The experimental results showed that the voltage difference of transmission line increases with the increasing frequency before 29 MHz while decreases after 35 MHz.A voltage difference platform occurs in the range of 29-35 MHz,which is suitable for measuring the moisture content due to its insensitivity to frequency.The electric field intensity gradually decreases with the increase of the probe depth,and the intensity of central probe is always greater than that of the edge probe.When the distance of the probe away from the sand sample surface is 80 mm,the electric field intensity of the edge probe is found to be very weak.The optimal excitation frequency for measuring the moisture content of green sand is 29-33 MHz.The optimal detector is the one with one center probe and three edge probes,and their lengths are 80 mm and 60 mm,respectively.The distance between the center and edge probes is 25 mm,and the diameter of probes is 5 mm.Taking the voltage difference of transmission line,bentonite content,coal powder content and compactability as parameters of the input layer,and the moisture content as a parameter of the output layer,a three-layer BP artificial neural network model for predicting the moisture content of green sand was constructed according to the experimental results at 33 MHz.The prediction error of the model is not higher than 3.3% when the moisture content of green sand is within the range of 3wt.%-7wt.%.

关键词： green sand dielectric property moisture content multiprobe detector BP artificial neural network 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

A simple image-based method for online moisture content estimation of iron ore green pellets

引用

Journal of Iron and Steel Research(International) 2023年第5期30卷 851-863页

作者： Shu-yi Zhou Xiao-yan Liu College of Electrical and Information Engineering Hunan UniversityChangsha 410082HunanChina Innovation Institute of Industrial Design and Machine Intelligence Quanzhou-Hunan University Quanzhou 362006FujianChina

moisture content(MC)is an important quality metric of iron ore green pellets in pelletizing process in ironmaking industry.Current image-based methods for MC estimation may result in big errors for gray-scale pellet images captured under various lighting conditions.We proposed a simple image-based method to improve the MC estimation accuracy by illumination correction and linear regression modeling.Firstly,the illumination of the pellet image was transformed into the reference illumination by use of a color checker chart and piecewise linear interpolation,so that the influence of different illuminations could be greatly reduced.By experimental analysis,it was found that MC is approximately adversely proportional to the average intensity of the transformed images.A simple model for MC prediction was then established by linear fitting.Experiments demonstrated that the proposed method has good robustness to different lighting conditions and achieves the best performance in metrics of mean square error,mean absolute error and maximum absolute error in comparison with five state-of-art MC estimating methods.Application on a working disk pelletizer shows that the proposed method can predict well the change of moisture content with time,and its computing efficiency can satisfy the requirement for online MC monitoring during the pelletizing process.

关键词： Green pellet moisture content Image processing Pelletizing process

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

Effects of moisture content and dry bulk density on the thermal conductivity of compacted backfill soil

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第8期23卷 610-620页

作者： Yu-hao WU Yan-hao FENG Li-wu FAN Qing WANG Xin SONG Zi-tao YU Institute of Thermal Science and Power Systems Zhejiang UniversityHangzhou 310027China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China Institute of Soil Science Chinese Academy of SciencesNanjing 210008China

Soil backfilling and compaction are often involved in urban construction projects like the burying of power cables.The thermal conductance of backfill soil is therefore of great interest.To investigate the thermal conductivity variation of compacted backfill soil,10 typical soils sampled in Zhejiang Province of China with moisture contents of 0%–25%were fully compacted according to the Proctor compaction test method and then subjected to thermal conductivity measurement using the thermal probe method at 20℃.The particle size distribution and the chemical composition of the soil samples were characterized to analyze their effects on thermal conductivity.The results showed that the maximum thermal conductivity of fully compacted soils generally exceeds 1.9 W/(m·K)and is 20%–50%higher than that of uncompacted soils.With increasing moisture content,soil thermal conductivity and dry bulk density first increase and then remain unchanged or decrease slowly;the critical moisture content is greater than 20%in most cases.Overall,the critical moisture content of soils with large particle size is lower than that of those with small particle size.Quartz has the highest thermal conductivity in the soil solid phase,and the mass percentage of quartz for most soils in this study is more than 50%,while that for yellow soil is less than 30%,which leads to the thermal conductivity of the former being nearly twice as great as that of the latter in most circumstances.Based on regression analysis,with moisture content and dry bulk density as the independent parameters,the prediction formulae for the thermal conductivity of two categories of compacted backfill soils are proposed for practical applications.

关键词： Backfill soil Compaction Thermal conductivity moisture content Dry bulk density

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

The effects of humus moisture content on underground fires in a Larix gmelinii plantation

引用

Journal of Forestry Research 2022年第3期33卷 865-873页

作者： Xiyue Han Hening Xu Tiantian Wang Sainan Yin Bo Gao Yajun Wang Yanlong Shan Beihua University Science and Technology Innovation Center of Wildland Fire Prevention and Control Forestry College of Beihua University3999 Binjiang East RoadJilin City132013Jilin ProvincePeople’s Republic of China

Underground fires are a smoldering combustion with a slow spread rate, low temperatures and no flame. They can last from days to several months, and can even become overwintering fires. They are difficult to find, leading to considerable damage to the forests. The moisture content of combustible fuels is an important factor in the occurrence and persistence of underground forest fires. The Daxing’an Mountains are a hot spot for underground fires in China. This paper looks at the influence of different moisture contents on underground fire characteristics using simulation combustion experiments in the laboratory. The study showed that peak temperature and spread rate fluctuation of humus at different moisture levels increased with humus depth. Peak temperature and spread rate fluctuation of humus at different depths decreased with increased moisture;moisture content and depth of humus had a significant effect on peak temperature and spread rate fluctuation;peak temperature at different depths decreased with increased moisture;the spread rate in upper layers increased with moisture content, while the spread rate in the lower layers decreased with increased moisture content.

关键词： Daxing’an Mountains Underground fire moisture content Peak temperature Spread rate

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

Study of corn kernel breakage susceptibility as a function of its moisture content by using a laboratory grinding method

引用

Journal of Integrative Agriculture 2022年第1期21卷 70-77页

作者： GUO Ya-nan HOU Liang-yu LI Lu-lu GAO Shang HOU Jun-feng MING Bo XIE Rui-zhi XUE Jun HOU Peng WANG Ke-ru LI Shao-kun Institute of Crop Sciences Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and EcologyMinistry of Agriculture and Rural AffairsBeijing 100081P.R.China Key Laboratory of Oasis Eco-Agriculture Xinjiang Production and Construction Corps/Agricultural CollegeShihezi UniversityShihezi 832000P.R.China

The rate of corn kernel breakage in the grain combine harvesters is a crucial factor affecting the quality of the grain shelled in the field. The objective of the present study was to determine the susceptibility of corn kernels to breakage based on the kernel moisture content in order to determine the moisture content that corresponds to the lowest rate of breakage.In addition, we evaluated the resistance to breakage of various corn cultivars. A total of 17 different corn cultivars were planted at two different sowing dates at the Beibuchang Experiment Station, Beijing and the Xinxiang Experiment Station(Henan Province) of the Chinese Academy of Agricultural Sciences. The corn kernel moisture content was systematically monitored and recorded over time, and the breakage rate was measured by using the grinding method. The results for all grain samples from the two experimental stations revealed that the breakage rate y is quadratic in moisture content x,y=0.0796 x^(2)-3.3929 x+78.779;R^(2)0=0.2646, n=512. By fitting to the regression equation, a minimum corn kernel breakage rate of 42.62% was obtained, corresponding to a corn kernel moisture content of 21.31%. Furthermore, in the 90% confidence interval, the corn kernel moisture ranging from 19.7 to 22.3% led to the lowest kernel breakage rate, which was consistent with the corn kernel moisture content allowing the lowest breakage rate of corn kernels shelled in the field with combine grain harvesters. Using the lowest breakage rate as the critical point, the correlation between breakage rate and moisture content was significantly negative for low moisture content but positive for high moisture content. The slope and correlation coefficient of the linear regression equation indicated that high moisture content led to greater sensitivity and correlation between grain breakage and moisture content. At the Beibuchang Experiment Station, the corn cultivars resistant to breakage were Zhengdan 958(ZD958) and Fengken 139(FK139), and the corn cultivars non-resistant to br

关键词： corn variety corn kernel breakage susceptibility moisture content grinding method

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

Experimental investigation on the gravity driven discharge of cohesive particles from a silo with two outlets

引用

Particuology 2024年第6期89卷 11-21页

作者： Li Dai Zhulin Yuan Fengxian Fan Conghui Gu School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China

An experimental study on the gravity driven discharge of cohesive particles from a silo with two outlets was performed.The discharge behaviors under the conditions that a single outlet was open and two outlets were open were investigated by varying the moisture content of the particles and the filling height of the particles in the silo.The results show that the discharge rate of the cohesive particles increases gradually at the beginning,then almost keeps constant,and finally drops obviously.The discharge rate in case of two openings is around 1.1–1.6 times that in case of a single opening.Larger filling height leads to lower discharge rate in case of a single opening but results in higher discharge rate in case of two openings.Furthermore,the avalanche dynamics in case of a single opening was examined,and the mixing behavior of the cohesive particles was evaluated.It is observed that the discharge flow is promoted by the avalanche phenomenon in the silo,generating a general trend that the normalized mass of discharge increases with the filling height at higher moisture contents.In case of a single opening,the transition from mass flow to funnel flow favors the particle mixing,resulting in an increasing mixing index as the moisture content increases.In general,a better performance of mixing can be achieved in case of a single opening compared with in case of two openings.This study provides vital information for fundamental understanding of the gravity driven discharge of cohesive particles from the silo with multiple outlets.

关键词： Cohesive particles moisture content Discharge rate Avalanche Mixing

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

An interdigitated impedance microsensor for detection of moisture content in engine oil

引用

Nanotechnology and Precision Engineering 2020年第2期3卷 75-80页

作者： Haitao Liu Xiecheng Tang Hao Lu Wenguang Xie Yanmin Hu Qiannan Xue State Key Laboratory of Precision Measuring Technology and Instruments School of Precision Instruments and Optoelectronics EngineeringTianjin UniversityTianjin 300072China Sino-European Institute of Aviation Engineering Civil Aviation University of ChinaTianjin 300300China College of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China Civil Aircraft Airworthiness Certification Technology Key Laboratory of Tianjin Civil Aviation University of ChinaTianjin 300300China

To address the need for the on-site measurement of aging oil, in this paper, we propose an impedance-based microsensor for analyzing the moisture content in engine oil. Using a microfabrication process, we fabricated an interdigitated microelectrode and integrated it with a 3 D-printed microcontainer to produce a microsensor that can detect changes in the permittivity of oil. When the moisture content in oil increases, this sensor can detect the resulting change in the oil impedance, which is related to its permittivity, and then determine the degree to which the oil has aged. The test results show that the proposed microsensor has the advantages of being small and having high sensitivity, good accuracy, and the ability to be combined with hand-held instruments.The proposed method is expected to be used for the rapid, low cost, on-site determination of oil aging.

关键词： Complex permittivity Oil detection Microsensor moisture content Impedance sensor

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

An experimental study of temperature and moisture content of wet porous materials under short-pulsed laser heating

引用

Journal of University of Science and Technology Beijing 2005年第5期12卷 476-480页

作者： Renxi Jin Xiulan Huai Nuclear Power Teaching Unit Naval Submarine Academy Shandong 266071 China Institute of Engineering Thermophysics Chinese Academy of Science Beijing 100080 China

The measurements of temperature and moisture content of a wet porous material were accomplished on the micro-seconds scale. The temperature wave was observed when the wet porous material was heated by short-pulsed laser with high power. It firstly revealed that the moisture content of wet porous material rapidly rises twice in one laser irradiation. The influences of laser parameters, the thickness and initial moisture content of the wet porous material on its temperature and moisture content were investigated.

关键词： porous material transient measurement temperature moisture content short-pulsed laser

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

Opto-thermal moisture content and moisture Depth Profile Measurements in Organic Materials

引用

Chemical Research in Chinese Universities 2004年第4期20卷 417-420页

作者： XIAOPeng GUOXin-xin CUIYing-xin RobertE.Imhof DaneBicanic SchoolofEngineering SouthBankUniversity103BoroughRoadLondonSE10AAUK DepartmentofMechanicalandIndustrialEngineering UniversityofToronto5King＇sCollegeRdTorontoOntarioMSS3G8Canada DepartmentofAgrotechnologyandFoodSciences WageningenUniversityandResearchCentreBomenweg46503HDWageningenTheNetherlands

Opto-thermal transient emission radiometry(OTTER) is a infrared remote sensing technique, which has been successfully used in in vivoskin moisture content and skin moisture depth profiling measurements. In present paper, we extend this moisture content measurement capability to analyze the moisture content of fruit(tomato, grape, etc.) skins, and to study the relationship between fruits ripening process and their surface moisture and moisture depth profiles.

关键词： Laser Opto-thermal radiometry Infrared moisture content Depth profiling Organic material

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

A Survey of Sediment Fineness and moisture content in the Soyang Lake Floodplain Using GPS Data

引用

Engineering 2021年第2期7卷 252-259页

作者： Mutiara Syifa Prima Riza Kadavi Sung Jae Park Chang-Wook Lee Division of Science Education Kangwon National UniversityGangwon-do 24341Republic of Korea

Soyang Lake is the largest lake in Republic of Korea bordering Chuncheon,Yanggu,and Inje in Gangwon Province.It is widely used as an environmental resource for hydropower,flood control,and water supply.Therefore,we conducted a survey of the floodplain of Soyang Lake to analyze the sediments in the area.We used global positioning system(GPS)data and aerial photography to monitor sediment deposits in the Soyang Lake floodplain.Data from three GPS units were compared to determine the accuracy of sampling location measurement.Sediment samples were collected at three sites:two in the eastern region of the floodplain and one in the western region.A total of eight samples were collected:Three samples were collected at 10 cm intervals to a depth of 30 cm from each site of the eastern sampling point,and two samples were collected at depths of 10 and 30 cm at the western sampling point.Samples were collected and analyzed for vertical and horizontal trends in particle size and moisture content.The sizes of the sediment samples ranged from coarse to very coarse sediments with a negative slope,which indicate eastward movement from the breach.The probability of a breach was indicated by the high water content at the eastern side of the floodplain,with the eastern sites showing a higher probability than the western sites.The results of this study indicate that analyses of grain fineness,moisture content,sediment deposits,and sediment removal rates can be used to understand and predict the direction of breach movement and sediment distribution in Soyang Lake.

关键词： Soyang Lake Grain fineness number moisture content GPS data Digital surface 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

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：