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A conformal invariance for generalized Birkhoff equations

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Acta Mechanica Sinica 2008年第5期24卷 583-585页

作者： Fengxiang mei Jiafang xie Tieqiang Gang Faculty of Science Beijing Institute of TechnologyBeijing 100081 China

In this article, generalized Birkhoff equations are put forward by adding supplementary terms to the Birkhoff equations. A conformal invariance of the Birkhoff equations can be used to study the generalized Birkhoff E... 详细信息

关键词： Generalized Birkhoff equations Conformal invariance Lie symmetry Noether symmetry

Image Classification with Superpixels and Feature Fusion Method

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Journal of Electronic Science and Technology 2021年第1期19卷 70-78页

作者： Feng Yang Zheng Ma mei xie the School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731

This paper presents an effective image classification algorithm based on superpixels and feature *** from classical image classification algorithms that extract feature descriptors directly from the original image,the proposed method first segments the input image into superpixels and,then,several different types of features are calculated according to these *** increase classification accuracy,the dimensions of these features are reduced using the principal component analysis(PCA)algorithm followed by a weighted serial feature fusion *** constructing a coding dictionary using the nonnegative matrix factorization(NMF)algorithm,the input image is recognized by a support vector machine(SVM)*** effectiveness of the proposed method was tested on the public Scene-15,Caltech-101,and Caltech-256 datasets,and the experimental results demonstrate that the proposed method can effectively improve image classification accuracy.

关键词： Dimension reduction feature fusion image classification.

Effect of MgO Critical Particle Size on Properties of MgO-C Continuous Temperature-Measuring Sensor for Liquid Steel

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Journal of Iron and Steel Research International 2011年第12期18卷 12-21页

作者： ZHAO Shu-mao mei Guo-hui xie Zhi College of Information Science and Engineering Northestern University Shenyang 110004 Liaoning China

MgO-C continuous temperature-measuring sensors for liquid steel were made of fused magnesia with different critical particle sizes from 0.5 to 2.0 mm,thus the effects what magnesia＇s particle size affect sensors＇ properties and lifetime were *** result shows that the MgO-C continuous temperature-measuring sensor has good aggression resistance to basic tundish powders and meets the requirement for response time of temperature measuring practice in *** sensor＇s service life,which is affected by multi-properties of material and operating environment,reached its maximum when the critical particle size of magnesia was 1.0 *** average lifetime of sensors was 43 or 40 h when served for casting SPHC or Q195 steel.

关键词： MgO carbon microstructure sensors lifetime particle size

The Synthesis and Characterization of High Molecular Weight Poly(phenylene sulfide/ether)

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Chinese Chemical Letters 2006年第10期17卷 1373-1376页

作者： Ai Qun GU mei Ju xie Zi Li YU Institute of Materials Science ＆ Technology Analytical ＆ Testing Center Sichuan University Chengdu 610064

Poly（phenylene sulfide/ether）（PPSE） was synthesized from 4,4＇-dihydroxydiphenyl sulfide and 4,4＇-dichlorodiphenyl sulfide in solution by nucleophilic substitution reaction. The resulting polymer was characterized by viscosity measurement, elemental analysis, FT-IR, ^1H NMR, X-ray diffraction and thermal analysis. The results showed that the viscosities of the resulting polymer were above 0.68 dL/g, and the linear chain structure of product was confirmed. PPSE had the same reflex indices as poly（p-phenylene sulfide）, an orthorhombic crystalline with unit cell a=0.853, b=0.562, c=1.026nm. The melting temperature, glass transition temperature and initial decomposition temperature were found to be 228℃, 85℃ and 325℃, respectively. The product was soluble in common organic solvents such as NMP, N, N＇-dimethylformamide, N, N＇-dimethylacetamide and 1,2-dichloroethane.

关键词： Poly(phenylene sulfide/ether) (PPSE) synthesis characterization.

Weakly Noether Symmetry for Nonholonomic Systems of Chetaev's Type

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Communications in Theoretical Physics 2008年第6期49卷 1413-1416页

作者： mei Feng-Xiang xie Jia-Fang GANG Tie-Qiang Department of Mechanics Beijing Institute of Technology Beijing 100081 China

In the paper [J. of Beijing Institute of Technology 26 （2006） 285] the authors provided the definition of weakly Noether symmetry. We now discuss the weakly Noether symmetry for non-holonomic system of Chetaev＇s type, and present expressions of three kinds of conserved quantities by weakly Noether symmetry. Finally, the application of this new result is shown by a practical example.

关键词： weakly Noether symmetry conserved quantity nonholonomic systems of Chetaev's type

Application of SWAN+ADCIRC to tide-surge and wave simulation in Gulf of Maine during Patriot's Day storm

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Water Science and Engineering 2016年第1期9卷 33-41页

作者： Dong-mei xie Qing-ping Zou John W.Cannon Department of Civil and Environmental Engineering University of Maine National Oceanic and Atmospheric Administration National Weather Service

The southern coast of the Gulf of Maine in the United States is prone to flooding caused by nor＇easters. A state-of-the-art fully-coupled model, the Simulating WAves Nearshore （SWAN） model with unstructured grids and the ADvanced CIRCulation （ADCIRC） model, was used to study the hydrodynamic response in the Gulf of Maine during the Patriot＇s Day storm of 2007, a notable example of nor＇easters in this area. The model predictions agree well with the observed tide-surges and waves during this storm event. Waves and circulation in the Gulf of Maine were analyzed. The Georges Bank plays an important role in dissipating wave energy through the bottom friction when waves propagate over the bank from offshore to the inner gulf due to its shallow bathymetry. Wave energy dissipation results in decreasing significant wave height （SWH） in the cross-bank direction and wave radiation stress gradient, which in turn induces changes in currents. While the tidal currents are dominant over the Georges Bank and in the Bay of Fundy, the residual currents generated by the meteorological forcing and waves are significant over the Georges Bank and in the coastal area and can reach 0.3 m/s and 0.2 m/s, respectively. In the vicinity of the coast, the longshore current generated by the surface wind stress and wave radiation stress acting parallel to the coastline is inversely proportional to the water depth and will eventually be limited by the bottom friction. The storm surge level reaches 0.8 m along the western periphery of the Gulf of Maine while the wave set-up due to radiation stress variation reaches 0.2 m. Therefore, it is significant to coastal flooding.

关键词： Nor'easter SWAN ADCIRC Gulf of Maine Patriot's Day storm Tide-surge Wave Coastal flooding

Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation

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World Journal of Clinical Cases 2019年第15期7卷 2003-2012页

作者： Jia-Xing Sun Ai-Lu Cai Li-mei xie Ultrasound Department Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina Ultrasound Department Roicare Hospital and ClinicsShenyang 110004Liaoning ProvinceChina

BACKGROUND Heart defects are the most common congenital malformations in *** cardiac structure and function abnormalities lead to changes in ventricular *** ventricular volume is an important index for evaluating fetal cardiovascular development,an effective and reliable method for measuring fetal ventricular volume and cardiac function is necessary for accurate ultrasonic diagnosis and effective clinical *** new intelligent spatiotemporal image correlation(iSTIC)technology acquires high-resolution volumetric *** this study,the iSTIC technique was used to measure right ventricular volume and to evaluate right ventricular systolic function to provide a more accurate and convenient evaluation of fetal heart *** To investigate the value of iSTIC in evaluating right ventricular volume and systolic function in normal *** Between October 2014 and September 2015,a total of 123 pregnant women received prenatal ultrasound examinations in our *** technology was used to acquire the entire fetal cardiac volume with off-line analysis using QLAB *** systolic and diastolic phases were defined by opening of the atrioventricular valve and the subsequent closure of the atrioventricular *** volumetric data of the two phases were measured by manual tracking and summation of multiple slices and recording of the right ventricular end-systolic volume and the right ventricular end-diastolic *** data were used to calculate the right stroke volume,the right cardiac output,and the right ejection *** correlations of changes between the above-mentioned indices and gestational age were *** right ventricular volumes of 30 randomly selected cases were measured twice by the same sonographer,and the intraobserver agreement measurements were *** Among the 123 normal fetuses,the mean right ventricular end-diastolic volume increased from 0.99±0.34 mL at 22 wk gestation to 3.69±0.36

关键词： Ultrasonography Fetus Intelligent spatiotemporal image correlation Right ventricular volume Cardiac function

Unique Damping Properties of Modified Eucommia Ulmoides Gum Bearing Polar and Branched Pendants

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Chinese Journal of Polymer Science 2023年第6期41卷 915-925,I0008页

作者： Zhi-Ying Han Heng-Chen Zhang You-Ji Li Ying Quan mei-Ran xie School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200241China National&Local United Engineering Laboratory of Integrative Utilization Technology of Eucommia Ulmoides College of Chemistry and Chemical EngineeringJishou UniversityJishou416000China

Eucommia ulmoides gum(EUG)was a biobased hard rubber with the prospected broad applications in rubber products,whereas possessed poor elasticity and weak damping functionality at room *** modification of EUG by triazolinedione-based Alder-ene reaction,the modified EUG containing varied amount of polar and branched pendants could become a new type of soft rubber and functional material with excellent damping properties,and especially exhibited the unique damping plateau with a wide effective damping temperature range of 132℃ covering from-35℃ to 97℃,large loss factor of 0.8,high damping coefficient of 0.53,and more hysteresis loss of ***,this sustainable elastomeric material with adjustable damping performance would absorb more vibrational mechanical energy in a wide temperature range,and have broadened applications in energy-absorption devices and shock-absorbing materials.

关键词： rubber Polar Modified

Study on the reform of resource tax and sustainable development of the underdeveloped resource-rich regions in China

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Ecological Economy 2007年第3期3卷 266-275页

作者： xie mei＇e Gu Shuzhong Institute of Geographic Science and Natural Resources Research Chinese Academy of SciencesBeijing 100101.P.R.China

The underdeveloped resource-rich region in China refers to the underdeveloped region with abundantnatural resources. The problem for these regions sustainable development cannot be negligible for its particularity innatural resources and environment. This paper mainly examines the issue about resource tax reform and the sustainabledevelopment of underdeveloped resource-rich regions. It first expatiates on regional characteristics of underdevelopedresource-rich regions, then analyzes the effect that resource tax has on the sustainable development of this type of regions,takes Yulin City as example to illuminate the negative influence on the sustainable development of those regions due to thedesign limitation of the existing resource tax, and put forward some suggestions, including to delegate tax legislativepower to lower levels, to increase resource tax rate, to expand its levied scope to give play to the potential main tax to localrevenue, to improve the design of resource tax, to enhance the its function of resource saving and environmentalprotection, to attach importance to regional interest of underdeveloped resource-rich regions and to improve of theinterest distribution system concerning the tax system and resource exploitation.

关键词： Resource tax Reform Underdeveipled regions Resource-rich regions Sustainable development