检索结果-南通市图书馆

Extraction of vegetation fraction information from CBERS images based on VBSI vegetation index in Kaixian county

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中国有色金属学会会刊：英文版 2011年第S3期21卷 712-716页

作者： GAO Zhi-fang1, NIU Hai-peng1, LIU Jin-ping2.1. college of Surveying and Land Information engineering, {2. polytechnic university, Jiaozuo 454000, China 2. college of Geographic Sciences, Chongqing Normal university, Chongqing 400047, China college of Surveying and Land Information engineering Henan Polytechnic University Jiaozuo 454000 China college of Geographic Sciences Chongqing Normal University Chongqing 400047 China

Based on the mixed pixel model, the vegetation fraction of Kaixian county, China, was extracted with three free CBERS images. VBSI vegetation index suitable for CBERS images constructed with FCD (forest canopy density) model principle was put forward by ITTO (International Tropical Timber Organization) was used, considering the underestimation of vegetation fraction using NDVI in low mountain-hill region influenced by soils and shadows. And vegetation fraction was divided into five categories from low to high in order to study the special variation of vegetation cover. The results show that the vegetation cover of the region is overall good, with an average of 50%. The area of vegetation fraction below 30% accounts for 11.7% of the entire studied area, mainly concentrates in central eastern Kaixian county, where is the major development zone of cities and towns; that between 30% and 60% accounts for 62.; and that higher than 60% accounts for 2.%, and mostly locates in northern middle-mountain area.

关键词： VBSI vegetation index mixed pixel model FCD model CBERS

Relationship between surface subsidence factor and mining depth of strip pillar mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 594-598页

作者： GUO Wen-bing1, 2. HOU Quan-lin 1, ZOU You-feng2.1. college of Earth Science, Graduate university of Chinese Academy of Sciences, Beijing 100049, China 2. School of Energy Science and {2., henan polytechnic university, Jiaozuo 454000, China college of Earth Science Graduate University of Chinese Academy of Sciences Beijing 100049 China School of Energy Science and engineering Henan Polytechnic University Jiaozuo 454000 China

Strip pillar mining is one of the most important technical measures to control mining subsidence in China. Mining depth is one of the most important factors that can affect the mining subsidence in strip pillar mining. Six numerical simulation models were set up to simulate the surface subsidence of strip pillar mining in different mining depths. The mining depth in these six models ranges from 300 to 800 m. The simulated results were compared and analyzed. The formula was established based on the simulated results. It demonstrated that the subsidence of strip pillar mining method is related to mining depth. While the other conditions are the same, the subsidence of strip pillar mining increases with the increase of mining depth by logarithmic relationship.

关键词： subsidence factor strip pillar mining mining depth numerical simulation

Suitability evaluation for land reclamation in mining area:A case study of Gaoqiao bauxite mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 506-515页

作者： WANG Shi-dong1, 2. LIU Chang-hua2. ZHANG He-bing2.1. college of Resources Science and Technology, Beijing Normal university, Beijing 100875, China 2. School of Surveying and Land Information {2., henan polytechnic university, Jiaozuo 454000, China college of Resources Science and Technology Beijing Normal University Beijing 100875 China School of Surveying and Land Information engineering Henan Polytechnic University Jiaozuo 454000 China

Suitability evaluation plays an important role in land reclamation because the choice of evaluation methods affects the accuracy and objectivity of the suitability evaluation results. Furthermore, it influences the decision-making related to land reclamation. An improved method, which is called limit comprehensive conditions method, was developed after different suitability evaluation methods were studied. Based on this method, the reclaimed land of the Gaoqiao bauxite mining area was evaluated. The Gaoqiao mining area was divided into seven evaluation units that were evaluated respectively by selecting evaluation factors and establishing grade standards. The results show that the proposed method is more applicable and easier to handle. Moreover, its evaluation results are more scientific compared with the traditional evaluation methods. The improved method can be beneficial to the rapid monitoring and the effective management of reclaimed land in the opencast mine area.

关键词： mining area land reclamation suitability evaluation Gaoqiao bauxite mine

Digital close-range photogrammetric application to small-scale physical simulation experiment

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中国有色金属学会会刊：英文版 2011年第S3期21卷 681-685页

作者： LI Chun-yi1, CUI Xi-min2. YU Yi-ju3 1. School of Surveying and Landing Information engineering, henan {2. university, Jiaozuo 454003, China 2. college of Geoscience and Surveying engineering, China university of Mining and Technology, Beijing 100083, China 3. Surveying and Mapping Press, Beijing 100045, China School of Surveying and Landing Information engineering Henan Polytechnic University Jiaozuo 454003 China college of Geoscience and Surveying engineering China University of Mining and Technology Beijing 100083 China Surveying and Mapping Press Beijing 100045 China

In order to research the possibility of digital close-range photogrammetric surveying in small scale physical simulation experiment, physical model coinciding with engineering practice was constructed based on similar theory. The datum processing method and surveying precision of digital close-range photogrammetric were analyzed. And the function relationship between overburden subsidence factor qr and the ratio z/H of stratum horizon z and mining depth H was researched. The results show that surveying points position mean error along horizontal direction is ±0.131 mm and vertical direction is ±0.192.mm. Therefore, multi-taking station cross direction digital close-range photogrammetric can completely satisfy the precision need of physical simulation experiment. And the empirical formula can be utilized to represent evolution law of stratum subsidence factor.

关键词： close-range photogrammetric physical simulation light-rays adjustment surveying precision subsidence factor

Effects of compressing and remelting in SIMA processing on semi-solid structure evolution of an Al-Zn wrought alloy

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Rare Metals 2003年第3期22卷 185-191页

作者： LIUChangming ZOUMaohua collegeofMechanicalEngineedng ChongqingUniversityChongqing400044China collegeofpolytechnic ChongqingUniversityChongqing400044China

Structure evolution of an Al-Zn wrought alloy in remelting processing in thestrain induced melt activated (SIMA) serai-solid procedure was observed, and effects of factors, theremelting temperature, the holding time, and the compression strain, on structures and grain sizesof the alloy were investigated. The results show that (1) the proper temperature of remelting is inthe range of 610 to 615℃; (2. the grain size in specimen with greater compression strain is smallerthan that with smaller compression strain in condition of the same remelting temperature andholding time, and the grain size in local area with great local equivalent strain is smaller thanthat with small one; (3) liquid occurs in form of cluster in matrix during remelting and itsquantity increases with remelting time increasing; liquid in specimen with great compression strainoccurs earlier than that with small one, and quantity of liquid in the center of specimen withgreater local equivalent strain is greater than that in the two ends of it; (4) distortion energyafter deforming in matrix of the alloy is the significant factor to activate melting of matrix atlocal area with great local equivalent strain.

关键词： semi-solid structure evolution strain induced melt activated processing semi-solid remelting Al-Zn alloy

APPLICATION OF VECTOR ROTATING METHOD IN GRINDING INVOLUTE WORM WITH PLANE ENVELOPE METHOD

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Chinese Journal of Mechanical engineering 1999年第4期12卷 317-320页

作者： Shang Xiangdong Fu Jingshun college of Mechanical engineering,Shenyang {2. university Duan Zhenyun Dalian university of Technology 沈阳工业大学机械工程学院辽宁沈阳大连理工大学辽宁大连

The grinding principle of plane envelope is demonstrated with the medium rack *** basic and general fixing patterns of grinding involute worms with plane envelope method are *** vector rotating method is originally applied to calculate precisely the grinding wheel fixing angles γ h and γ n under the general fixing *** is proved with experiments that the method is feasible.

关键词： Medium rack Vector rotating Plane envelope Worm grinding

Expansive Behaviors of Self-stressing Concrete under Different Restraining Conditions

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Journal of Wuhan university of Technology(Materials Science) 2011年第4期26卷 780-785页

作者：常旭 college of Civil engineering Henan Polytechnic University

The expansive behaviors of the expensive concrete under different restraining conditions were systemically studied. The experimental results indicate that expansive deformation obviously increases before 10 days and tends to be constant after 2. days regardless of the restraining conditions. The mixture ratio of expansive cement and restraining conditions are the main factors affecting expansive deformation. Self-stress can be obtained when the expansive deformation is restrained. The higher self-stress could be obtained when the expensive concrete is restrained by steel tube. For specimens under steel tube restraining, the wall thickness and the length of the steel tube have important influence on self-stress. Both the radial self-stress and axial self-stress in concrete core increase when wall thickness or length of the steel tube increases.

关键词： self-stress expansive concrete restraining condition

Electronic Structure and Thermoelectric Properties of Ca_3Co_4O_9

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Journal of Wuhan university of Technology(Materials Science) 2006年第1期21卷 13-15页

作者：闵新民 Department of Applied Chemistry Wuhan University of TechnologyWuhan 430070China

The relation among electronic structure, chemical bond and thermoelectric property of Ca3 Co4 O9 was studied using density function and discrete variation method （DFT-DVM）. The gap between the highest valence band （HVB） and the lowest conduction band （LCB） shows a semiconducting property. Ca3 Co4 O9 consists of CoO2.and Ca2.CoO3 two layers. The HVB and LCB near Fermi level are only mainly from O（ 2.） 2. and Co （2. 3d in Ca2.CoO3 layer. Therefore, the semiconducting or thermoelectric property of Ca3 Co4 O9 should be mainly from Ca2.CoO3 layer, but it seems to have no direct relation to the CoO2.layer, which is consistent with that binary oxides hardly have a thermoelectric property, but trinary oxide compounds have quite a good thermoelectric property. The covalent and ionic bonds of Ca2.CoO3 layer are both weaker than those of CoO2.layer. Ca plays the role of connections between CoO2.and Ca2.CoO3 layers in Ca3 Co4 O9, decrease the ionic and covalent bond strength, and improve the thermoelectric property.

关键词： cobaltite electronic structure chemical bond thermoelectric property

Constraints on the late Mesozoic regional angular unconformity in West Liaoning-North Hebei by LA-ICP-MS dating

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Progress in Natural Science:Materials International 2008年第11期18卷 1395-1402页

作者： Hong Zhang~(a,b,*) Wenmin Guo~a Xiaoming Liu~b a college of Mechanical and Energy engineering,Jiangsu {2. university,Changzhou 2.3016,China b Key Laboratory of Continental Dynamics,Department of geology,Northwest university,Xi’an 710069,China college of Mechanical and Energy engineering Jiangsu Polytechnic University Changzhou 213016 China Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China

The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems,and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North ***,the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 135 Myr in the *** on the detailed study and systematic sampling in Yixian-Beipiao,Lingy- uan,Chengde and Luanping areas in the field,the authors obtained the following isotopic ages by means of LA-ICP-MS dating:In the Lingyuan area,the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact;the age range of the Zhangjiakou Formation volcanic rock is from 133 to 130 Myr(seven samples),and that of the Yixian Formation volcanic rock is from 12. to 12. Myr(eleven samples).In the Luotuoshan of Chengde,the Tuchengzi Formation and the Zhangjiakou Formation are in angu- lar unconformable contact;the age at the lower Zhangjiakou Formation is about 12. Myr(one sample),which reflects that the age range of the lower Zhangjiakou Formation is from 12. to 12. Myr combined with the previous *** the Luanping basin,there is the larg- est sediment gap in upper Mesozoic,whose lower boundary age is confined in 131 to 130 *** the Yixian-Beipiao area,the second Member of the Yixian Formation,making up more than 3/4 thickness of the Yixian Formation,was formed in 12. to 119 Myr,and the age of the Yixian Formation at the bottom is about 132.***,the upper boundary age of the Tuchengzi Formation is about 136 Myr in the West Liaoning-North Hebei *** on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region,it reflects that there was a widespread tectonic event in the period of 136 to 12. Myr (mainly in 130-12. Myr)in the West Liaoning-North Hebei,and it formed the

关键词： Dating LA-ICP-MS Angular unconformity Interface of tectonic transformation West Liaoning-North Hebei