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Advances in Atmospheric Sciences 2008年第5期25卷 765-777页

作者： Ki-Young HEO Kyung-ja HA Division of Earth Environmental System College of Natural Sciences Pusan National University Korea

This study investigates the characteristics of a heavy snowfall event over the southwestern part of the Korean Peninsula on 4 December 2005. The snowstorm was a type of mesoscale maritime cyclone which resulted from barotropic instability, and diabatic heating from the warm ocean in continental polar air masses. Based on surface observations, radiosonde soundings, MTSAT-1R satellite data and the 10-km grid RDAPS （Regional Assimilation and Prediction System based on the PSU/NCAR MM5） data, the evolution of the mesocyclone is explained by the following dynamics; （1） in the initial stage, the primary role in the cyclogenesis process of the mesocyclone is a barotropic instability in the horizontal shear zone. （2） in the developing stage, the mesocyclone moves and deepens into a baroclinic zone corresponding to the surface heating and moistening. （3） in the mature stage, it is found that the mesocyclone is intensified by the destabilization caused by enhanced low-level heating and condensation, the moisture flux convergence, and the interaction between upper and lower-level potential vorticity anomalies. We suggest that a checklist with stepwise indicators responsible for development be prepared for the forecasting of heavy snowfall over the southwestern part of the Korean Peninsula.

关键词： heavy snowfall mesocyclone baroclinic instability barotropic instability stepwise roles potential vorticity anomalies

Esophageal resection for high-grade dysplasia and intramucosal carcinoma: When and how?

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World Journal of Gastroenterology 2010年第30期16卷 3786-3792页

作者： Vani ja Konda Mark K Ferguson Department of Medicine The University of Chicago Pritzker School of MedicineChicagoIL 60637United States Department of Surgery The University of Chicago Pritzker School of MedicineChicagoIL 60637United States

High-grade dysplasia (HGD) and intramucosal carcinoma (iMC) in the setting of Barrett’s esophagus have traditionally been treated with esophagectomy. However, with the advent of endoscopic mucosal resection and endoscopic ablative therapies, endoscopic therapy at centers with expertise is now an established treatment of Barrett’s-esophagus-related neoplasia, including HGD and iMC. Esophagectomy is today reserved for more selected cases with submucosal invasion, evidence for lymph node metastasis, or unsuccessful endoscopic therapy.

关键词： Barrett’s esophagus High-grade dysplasia intramucosal carcinoma Endoscopic mucosal resection Esophagectomy

An accelerated K-means clustering algorithm using selection and erasure rules

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第10期13卷 761-768页

作者： Suiang-Shyan LEE ja-Chen LiN Department of Computer Science National Chiao Tung University

The K-means method is a well-known clustering algorithm with an extensive range of applications,such as biological classification,disease analysis,data mining,and image ***,the plain K-means method is not fast when the number of clusters or the number of data points becomes large.A modified K-means algorithm was presented by Fahim et al.(2006).The modified algorithm produced clusters whose mean square error was very similar to that of the plain K-means,but the execution time was *** this study,we try to further increase its *** are two rules in our method:a selection rule,used to acquire a good candidate as the initial center to be checked,and an erasure rule,used to delete one or many unqualified centers each time a specified condition is *** clustering results are identical to those of Fahim et al.(2006).However,our method further cuts computation time when the number of clusters *** mathematical reasoning used in our design is included.

关键词： K-means clustering Acceleration Vector quantization Selection Erasure

ON TraNSMiSSiON PROBLEM FOR ViSCOELASTiC WAVE EQUATiON WiTH A LOCALiZED A NONLiNEAR DiSSiPATiON

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Acta Mathematica Scientia 2013年第2期33卷 362-374页

作者： Jeong ja BAE Seong Sik KiM Department of Mathematics Dongeui UniversityPusan 614-714Korea

in this article, we consider the global existence and decay rates of solutions for the transmission problem of Kirchhoff type wave equations consisting of two physically different types of materials, one component being a Kirchhoff type wave equation with time dependent localized dissipation which is effective only on a neighborhood of certain part of boundary, while the other being a Kirchhoff type viscoelastic wave equation with nonlinear memory

关键词： Existence of solution uniform decay transmission problem boundary valueproblem localized dissipation

Spectrum and Singular integrals on a New Weighted Function Space

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Acta Mathematica Sinica,English Series 2018年第11期34卷 1692-1702页

作者： Hee Chul PAK Young ja PARK Department of Mathematics Dankook University Dandae-ro 119 Dongnam-gu Cheonan-si Chungnam 31116 Republic of Korea Department of Mathematics Hoseo University Hoeo-ro 79 Asan-si Chungnam 31499 Republic of Korea

We introduce a new function space that is much finer than the classical Lebesgue spaces, and investigate the continuity and the discontinuity of the Calderon-Zygmund operators on the new weighted spaces. in order to identify the continuity of singular integrals, we prove an interpolation theorem on the new spaces and propose a concept of the spectrum of base functions.

关键词： Function spaces singular integrals interpolation Calderdn Zygmund operators Holder's inequality L log L

Does climate change alter the nutrient trends of Cedrela fissilis Vell. trees in the southern Brazilian Amazon?

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Ecological Processes 2023年第4期12卷 164-185页

作者： Daigard R.Ortega Rodriguez raúl Sánchez-Salguero Andrea Hevia Renata C.Bovi Marciel J.Ferreira james H.Speer Fidel A.Roig Mario Tomazello-Filho Escola Superior de Agricultura Luiz de Queiroz Departamento de Ciências Florestais Universidade de S?o Paulo Dendr Olavide-Department Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide Department of Ecology Universidad de Jaén Campus Las Lagunillas s/n. Departamento de Ciência Florestal Solos e AmbienteUniversidade Estadual Paulista Laboratory of Silviculture Universidade Federal do Amazonas Department of Earth and Environmental Systems Indiana State University Argentine institute of Nivology Glaciology and Environmental Sciences(IANIGLA CONICET Universidad Nacional de Cuyo) Hémera Centro de Observación de la Tierra Escuela de Ingeniería Forestal Facultad de CienciasUniversidad Mayor

Background The increase in the frequency and intensity of droughts is pointed out as one of the main factors altering biogeochemical cycles in the Amazon basin. An eco-nutritional approach using X-ray fluorescence micro-analysis(μXRF) is proposed to verify the long-and short-term effects of droughts on the growth and xylem nutrient concentrations of Cedrela fissilis *** Fourteen radii were selected from a tree-ring width chronology and X-rayed by itrax Multiscanner. Profiles of ring width, wood density, and concentrations of aluminum(Al), phosphorus(P), sulfur(S), calcium(Ca), potassium(K), manganese(Mn), iron(Fe) and strontium(Sr) together with Al/Ca, Ca/Mn, K/Ca, Sr/Ca and Mn/S ratios were constructed and correlated with precipitation, temperature, the difference between precipitation and potential evapotranspiration(P-PET) and standardized precipitation–evapotranspiration index(SPEi).Results During dry years, C. fissilis showed narrower, less dense rings, lower Al, P, S and Ca, and higher K and Fe concentrations(the opposite was found in wet years). Ring width decreased(together with Al, P, S, K, Ca, Mn, Fe, Sr, Al/Ca, K/Ca and Sr/Ca) and wood density increased(together with Ca/Mn and Mn/S), which was associated with an increase in evapotranspiration and temperature over time, mainly since 1990. Cedrela fissilis showed a tendency to increase its capacity for resistance, and a recovery and resilience in growth over time associated with responses in Al, Ca, P and S. However, it showed a risk in the capacity for recovery of the pre-drought density values, associated with unsatisfactory responses in Al, Ca, K, Fe and *** This study is the first attempt to analyze tree-ring nutritional evidences of C. fissilis trees to climate sensitivity and resilience to drought, based on long-term data from seasonal moist tropical forests of the Amazon. Our data suggested that C. fissilis is undergoing alterations in the concentration, use and redistribution of n

关键词： Dendrochemistry µXRF Drought Tropical tree Eco-chemical indicator Resilience Resistance Recovery

improved block matching approach to fast disparity estimation

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1278-1285页

作者： Tao Tangfei ja Choon Koo Hyouk Ryeol Choi School of Mechanical Engineering Xi'an Jiaotong Univ. Xi'an 710049 P. R. China State Key Lab. for Manufacturing Systems Engineering Xi'an 710049 P. R. China School of Mechanical Engineering Sungkyunkwan Univ. Suwon Republic of Korea

An improved block matching approach to fast disparity estimation in machine vision applications is proposed, where the matching criterion is the sum of the absolute difference（SAD）.By evaluating the lower bounds, which become increasingly tighter for the matching criteria, the method tries to successively terminate unnecessary computations of the matching criteria between the reference block in one image and the ineligible candidate blocks in another *** also eliminates the ineligible blocks as early as possible, while ensuring the optimal disparity of each ***, the proposed method can further speed up the elimination of ineligible candidate blocks by efficiently using the continuous constraint of disparity to predict the initial disparity of each *** performance of the new algorithm is evaluated by carrying out a theoretical analysis, and by comparing its performance with the disparity estimation method based on the standard block *** results demonstrate that the proposed algorithm achieves a computational cost reduction of over 50.5% in comparision with the standard block matching method.

关键词： machine vision block matching disparity estimation sum of the absolute difference.

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莲子磨皮粉水提物的制备及其性能研究

日用化学品科学 2024年第2期47卷 11-17页

作者：王艺茅文瑄华中杰魏昀霏周文瑞贾焱北京工商大学化学与材料工程学院北京100048

以莲子磨皮粉为原料,在单因素实验的基础上通过正交实验法,得到了超声提取莲子磨皮粉中酚类的工艺参数,并实验测评了其抗氧化、美白功效。经正交试验,最佳工艺条件为:料液比为1︰30,超声温度70℃,提取时间为120 min。在此提取条件下,莲... 详细信息

以莲子磨皮粉为原料,在单因素实验的基础上通过正交实验法,得到了超声提取莲子磨皮粉中酚类的工艺参数,并实验测评了其抗氧化、美白功效。经正交试验,最佳工艺条件为:料液比为1︰30,超声温度70℃,提取时间为120 min。在此提取条件下,莲子磨皮粉水提物清除DPPH自由基的iC50为0.0180 mg/mL,清除ABTS自由基的i50为0.9286 mg/mL。莲子磨皮粉对DPPH自由基、ABTS自由基具有良好的清除效果,具有一定的抗氧化功效。在酪氨酸酶抑制实验中,半数抑制量为3.898 mg/mL,具有开发为美白原料的潜能。同时在红细胞溶血实验中,半数溶血浓度HD50为0.8321 mg/mL,各浓度的莲子磨皮粉水提物的溶血率均显著低于SDS溶液的溶血率,证明了莲子磨皮粉水提物具有低刺激性。

关键词：莲子磨皮粉超声提取多酚黄酮抗氧化活性酪氨酸酶红细胞溶血实验

Mechanical Behaviour of Composite Bioactive Bone Cements Consisting of Two Different Types of Surface Treated Hydroxyapatite as Filler

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Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 10-12页

作者： S Deb ja Roether Department of Biomaterials King's College London School of Dentistry at the Guy's King's & St Thomas Hospital Guy's Tower Guy's Hospital London Bridge London SE 1 9RT UK

Bioactive bone cements based on a paste-paste system for orthopaedic applications were developed consisting of hydroxyapatite （ HA ） filler panicles in a methacrylate matrix comprising urethane dimethacrylate （ UDMA ） and triethylene glycol dimethacrylate （ TEGDMA ）. To improve the interface between inorganic filler and organic matrix the HA panicles were subjected to two different surface treatment methods, using polyacrylic acid （PAA） and γ-methacryloxy propyl trimethoxy silane （γMPS）. The aim of the present study was to determine the influence of surface treatment and the inclusion of multifunctional methacrylates on the mechanical properties, namely 3-point flexural strength （FS） and fracture toughness of the cements and the effect of ageing in simulated body fluid. Comparing the mechanical properties of the two cements, the γMPS- HA cement showed that the fracture toughness of the experimental bone cements were significantly greater （ p 〈 0.001） compared to that of the PMMA cement, whereas PAA-HA containing cement had strength vollues around 20% lower. interestingly, PAA was found to be more effective in improving the interface as the PAA treated HA cement （ UTHAPPA ） maintained its strength on immersion in SBF, suggesting that PAA provided a coupling, which was less sensitive to moisture, a similar trend was also observed with the inclusion of the carboxyl containing multifunctional methacrylates.

关键词： bioactive bone cements coupling agents composites polyacrylic acid

Bound lipids in lacustrine sediments in Guchenghu Lake, East China

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Chinese Science Bulletin 1997年第21期42卷 1817-1820页

作者： Zhang, G Sheng, GY Fu, ja Chinese Acad Sci Guangzhou Inst Geochem Guangzhou 510640 Peoples R China

BiOMARKERS used as indicators of the paleoclimatic and paleoenvironmental changes are re-quired to be bio-specific in origin and be stable in the early diagenesis process. The input ofplenty of land-derived organics, as well as possible changes in the early diagenesis process,made the lipid composition of inland lacustrine sediments more complicated, and, as a result,the bio-indicating significance of some biomarkers often become obscured. Except for

关键词： bound lipids composition sources paleoenvironmental changes.