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IMAGE SEGMENTATION BY PIECEWISE CONSTANT MUMFORD-SHAH MODEL WITHOUT ESTIMATING THE CONSTANTS

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Journal of Computational Mathematics 2006年第3期24卷 435-443页

作者： xue-cheng Tai Chang-hui Yao CIPR Department of Mathematics University of Bergen Norway Department of Mathematics University of Bergen Norway

In this work, we try to use the so-called Piecewise Constant Level Set Method （PCLSM） for the Mumford-Shah segmentation model. For image segmentation, the Mumford-Shah model needs to find the regions and the constant values inside the regions for the segmen- tation. In order to use PCLSM for this purpose, we need to solve a minimization problem using the level set function and the constant values as minimization variables. In this work, we test on a model such that we only need to minimize with respect to the level set function, i.e., we do not need to minimize with respect to the constant values. Gradient descent method and Newton method are used to solve the Euler-Lagrange equation for the minimization problem. Numerical experiments are given to show the efficiency and advantages of the new model and algorithms.

关键词： PCLSM Image Segmentation Mumford-Shah model.

LINEAR FINITE ELEMENT APPROXIMATIONS FOR THE TIMOSHENKO BEAM AND THE SHALLOW ARCH PROBLEMS

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Journal of Computational Mathematics 2002年第1期20卷 15-22页

作者： Xiao-liang Cheng Wei-min xue Department of Mathematics Zhejiang UniversityXixi CampusHangzhou 310028China Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong Kong

Focuses on a study that discusses the linear finite element approximations for the Timoshenko beam and the shallow arch problems with shear dampening and reduced integration. Information on the Timoshenko beam; Detail... 详细信息

关键词： Timoshenko beam shallow arch shear dampening reduced integration

Corrosion behavior of low-carbon Cr micro-alloyed steel for grounding grids in simulated acidic soil

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Journal of Iron and Steel Research International 2018年第7期25卷 755-766页

作者： Jian Li Hang Su Feng Chai Dong-mei xue Li Li Xiang-yang Li hui-min Meng Division of Engineering Steel Central Iron and Steel Research Institute Beijing 100081 China Enterprise Management Department China Iron and Steel Research Institute Group Beijing 100081 China Corrosion and Protection Center University of Science and Technology Beijing Beijing 100083 China

To improve the corrosion resistance of steels for grounding grids, a low-carbon Cr micro-alloyed steel was developed （C 1 steel）, and corrosion behavior of Q235 steel and newly developed C1 steel in simulated acidic soil was investigated. The corrosion rate was evaluated with the mass loss measurements, while the corrosion morphology of surface and cross section of rust layer was observed by scanning electron microscopy. The corrosion products were analyzed by energy- dispersive X-ray spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy, and the polarization curve was measured using potentiodynamic polarization method. Results indicated that C 1 steel displayed good corrosion resistance in the simulated acidic soil, of which the corrosion rate was only 30% of that of Q235 steel after corrosion for 360 h. The analysis of rust layer showed that lower carbon content in steel could reduce the tendency of micro cell corrosion and appropriate amount of chromium could improve the corrosion potential of metal matrix. Moreover, the analysis of X-ray photoelectron spectroscopy revealed that the chromium enriched in inner rust layer of C1 steel existed mainly in the form of Fe2CrO4, which facilitated the formation of Cr-goethite and improved the protection of corrosion products.

关键词： Soil corrosion Grounding grid Low-carbon steel Cr micro-alloying Corrosion product - Cr-goethite

Tensile strength prediction of dual-phase Al0.6CoCrFeNi high-entropy alloys

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International Journal of minerals,Metallurgy and Materials 2020年第10期27卷 1341-1346页

作者： min Zhang Jin-xiong Hou hui-jun Yang Ya-qin Tan xue-jiao Wang Xiao-hui Shi Rui-peng Guo Jun-wei Qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

The evolution of the microstructure and tensile properties of dual-phase Al0.6CoCrFeNi high-entropy alloys(HEAs)subjected to cold rolling was *** homogenized Al0.6CoCrFeNi alloys consisted of face-centered-cubic and body-centered-cubic phases,presenting similar mechanical behavior as the as-cast *** yield and tensile strengths of the alloys could be dramatically enhanced to^1205 MPa and^1318 MPa after 50%rolling reduction,respectively.A power-law relationship was discovered between the strain-hardening exponent and rolling *** tensile strengths of this dual-phase HEA with different cold rolling treatments were predicted,mainly based on the Hollomon relationship,by the strain-hardening exponent,and showed good agreement with the experimental results.

关键词： dual-phase high-entropy alloys cold rolling strain-hardening exponent tensile strength

DISTRIBUTION OF LEAD IN URBAN SOIL AND ITS POTENTIAL RISK IN SHENYANG CITY, CHINA

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Chinese Geographical Science 2006年第2期16卷 127-132页

作者： WANG Jin-da REN hui-min LIU Jing-shuang YU Jun-bao ZHANG xue-lin Northeast Institute of Geography and A groecology Chinese Academy of Sciences Changchun 130012 P. R. China Graduate School of Chinese Academy of Sciences Beijing 100049 P. R. China

The horizontal and vertical distribution characteristics of Pb in urban soil of Shenyang City, China were investigated in this study. The range of Pb concentration in the soil was 22.02-2910.60mg/kg. The standard deviation was 443.07mg/kg, and coefficient of variation was 1.64. Tiexi District was seriously contaminated by lead. In general, Pb concentration in the soil decreased with distance from pollution source. Lead concentration varied in different functional areas with the order of industrial area>commercial area>residential area>suburb>reference area. Pb concentration decreased with the depth of soil profile. Both geo-accumulation index and ecological risk index were used to estimate the potential risk of soil Pb pollution in Shenyang City. The results showed that the high potential risk area included Tiexi District and traffic roads.

关键词： Pb in soil Pb distribution potential risk Shenyang City

The Dynamics of Changes in Starch and Lipid Droplets and Sub-Cellular Localization of β-Amylase During the Growth of Lily Bulbs

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Journal of Integrative Agriculture 2012年第4期11卷 585-592页

作者： WU Sha-sha WU Jin-di JIAO xue-hui ZHANG Qi-xiang LV Ying-min College of Landscape Architecture Beijing Forestry University Beijing 100083 P.R.China China National Research Center for Floriculture Engineering ＆ Technology Beijing 100083 P.R.China

The ultra-structure of mother and outer daughter scales of Lilium Oriental hybrid Sorbonne were studied using transmission electron microscope to examine the sub-cellular localization of starch and lipid droplets during growth and development from shoot emergence to *** contents of starch granules and lipid droplets in the cell of the mother scales decreased significantly from shoot emergence to anthesis,indicating that these scales served as a source for growth and *** flowering,the number of starch granules and lipid droplets increased dramatically,and finally the cells were filled with the above molecules indicating that the bulb becomes a major sink during bulb *** observation also showed that symplastic pathway is the main pathway in cells in the exchange and transportation of material during bulb *** activity of β-amylase,one of the key enzymes catalyzing starch breakdown,showed a similar *** enzyme sub-cellular localization via immune-gold electron-microscopy showed that βamylase was predominantly located together with starch granules,while the gold particles were scarcely found in other sub-cellular *** result suggested that this enzyme is compartmented together with its functional substrate supporting its function in catalyzing starch breakdown in living plant cells.

关键词： Lilium Oriental hybrids bulb scale source and sink ultra-structure β-amylase sub-cellular localization

Studies on the Structure of Gel during Preparing ZnO Thin Films by Sol-gel Method

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Chinese Journal of Structural Chemistry 2010年第7期29卷 1061-1066页

作者： QIN Xiu-Juan SUN xue-Liang BU Li-min ZUO Hua-Tong HANSI hui-Zhi College of Environmental and Chemical Engineering State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China

Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material. A novel structure on zinc citrate complex was put forward by using DTA-TG and FT-IR absorbanee spectrum of citrate gels. Phase formation, morphology and optical properties of ZnO films are investigated by XRD, AFM and UV-vis transmittance spectra. The experimental results show that ZnO thin films derived from zinc citrate sol-gel method showed a （002） oriented hexagonal wurtzite structure, good crystalline property, a uniform range of grain size （40 nm）, smooth surface of films, band gap of 3.28 eV and optical transmittances ratio over 90% in the visible range.

关键词： ZnO thin film inorganic complex sol-gel infrared spectra zinc citrate complex

Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats

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Neural Regeneration Research 2025年第5期20卷 1495-1504页

作者： Yunting Xiang Xiangxin Xing Xuyun Hua Yuwen Zhang Xin xue Jiajia Wu Mouxiong Zheng He Wang Jianguang Xu School of Rehabilitation Science Shanghai University of Traditional Chinese MedicineShanghaiChina Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation Ministry of EducationShanghaiChina Department of Rehabilitation Medicine Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese MedicineShanghaiChina Department of Traumatology and Orthopedics Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese MedicineShanghaiChina Institute of Science and Technology for Brain-Inspired Intelligence Fudan UniversityShanghaiChina Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence(Fudan University) Ministry of EducationShanghaiChina Human Phenome Institute Fudan UniversityShanghaiChina

Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected ***,differences among reconstruction strategies at the brain network level have not been *** study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve ***–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper ***-state brain functional magnetic resonance imaging was obtained 7 months after *** independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the *** in intra-network resting-state functional connectivity were compared among the *** muscle reinnervation was assessed by behavioral observation(elbow flexion)and *** results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural *** repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor *** thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve *** areas related to cognition and emotion were enhanced after end-to-side nerve *** study revealed important brain networks related to different nerve *** networks may be potential targets for enhancing motor recovery.

关键词： brain functional networks end-to-end nerve transfer end-to-side nerve transfer independent component analysis nerve repair peripheral plexus injury resting-state functional connectivity

Synthesis of a Pillar[5]arene with Both Hydroxyl and Methoxycarbonyl-Methoxy Groups and Its Host-Guest Complexation with a Bis(imidazolium)Salt

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Chinese Journal of Chemistry 2014年第2期32卷 128-132页

作者： mingguang Pan min xue Department of Chemistry Zhejiang UniversityHangzhouZhejiang 310027China

By the introduction of methoxycarbonyl-methoxy groups and hydroxyl groups into a pillar structure,a pillararene entirely with two types of functional groups was successfully prepared,which can form a stable 1∶1 compl... 详细信息

关键词： pillararenes functionalization bis(imidazolium) host-guest complexation self-assembly