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Acta Metallurgica Sinica(English Letters) 2017年第12期30卷 1185-1191页

作者： Hong-Min jia Xiao-Hui Feng Yuan-sheng Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China University of Chinese Academy of Sciences Beijing 100039China Shandong Key Laboratory for High Strength Lightweight Metallic Materials Ji'nan 250014 China

The microstructure evolution and growth orientation of directionally solidified Mg-4 wt% Zn alloy in the growth rate range from 20 to 200μm/s were investigated. A typical cellular structure was observed with a growth rate of 20 μm/s, and the cellular spacing was 115 μm. When the growth rate increased to 60 μm/s, cellular structure with some developed perturbations was obtained and the cellular spacing was 145 μm, suggesting that the cell-to-dendrite transition happened at the growth rate lower than 60 μm/s. As the growth rate further increased, the microstructure was dendritic and the primary dendritic arm spacing decreased. The relationship between the primary dendritic arm spacings and the growth rates was in good agreement with Trivedi model during dendritic growth. Besides, X-ray diffraction and transmission electron microscopy analyses showed that the growth direction of directionally solidified Mg-4 wt% Zn alloy was （1120） lay in {0002} crystal plane, and the preferred orientation was explained with the lattice vibration model for one-dimensional monatomic chain.

关键词： Directional solidification Mg-Zn alloy Microstructure evolution Primary dendritic arm spacing Growth orientation

Influence of Re-Ti modification on the high impact wear resistance of high Si bainitic cast steel

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 756-762页

作者： Jin-feng Huang Hong-sheng Fang Yan-kang Zheng State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijnig 100083 China Department of Materials Science and Engineering Tsinghna University Beijing 100084 China

The effect of rare earth （Re） and titanium （Ti） multi-modification on the impact wear behavior of Mn-B high-Si bainitic cast steel was investigated systematically. The experiments show that the impact wear resistance can be improved greatly with the addition of Re and Ti. Its wear loss is only about 1/3-1/2 as large as that of the unmodified bainitic cast steel. By the Re/Ti modification, coarse dendrite grains and bainitic/martensite duplex structure have been refined effectively, and the impact toughness of the bainitic cast steel is nearly tripled （10 mm×10 mm×55 mm, with unnotched sample）. Consequently, the modified bainitic cast steel possesses good wear resistance under high im- pact. For both modified and unmodified bainitic cast steels, high hardness white layer and deformed zone are developed beneath the worn surface under the high impact wear, but the formation and propagation of cracks are different for these bainitic casting steels. Different mod- els for the formation and propagation of cracks for both modified and unmodified bainitic cast steels under high impact wear are proposed.

关键词： cast steel modification grain refmement impact wear spalling

THE METHOD OF MULTIPLE SCALES APPLIED TO THE NONLINEAR STABILITY PROBLEM OF A TRUNCATED SHALLOW SPHERICAL SHELL OF VARIABLE THICKNESS WITH THE LARGE GEOMETRICAL PARAMETER

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Applied Mathematics and Mechanics(English Edition) 2001年第10期22卷 1198-1209页

作者： kang sheng-liang(康盛亮) Department of Applied Mathematics Tongji UniversityShanghai 200092 P R China

Using the modified method of multiple scales, the nonlinear stability of a truncated shallow spherical shell of variable thickness with a nondeformable rigid body at the center under compound loads is investigated. When the geometrical parameter k is larger, the uniformly valid asymptotic solutions of this problem are obtained and the remainder terms are estimated.

关键词： shallow shell of variable thickness nonlinear stability modified method of multiple scales

Magnetic properties and magnetocaloric effects of Gd65（Cu,Co,Mn）35 amorphous ribbons

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Journal of Materials Science & Technology 2019年第10期35卷 2283-2287页

作者： Peng jia Leipeng Duan kang Wang Engang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819China School of Metallurgy Northeastern UniversityShenyang110819China

The magnetic phase transition and magnetocaloric effects of Gd65(Cu,Co,Mn)35 amorphous ribbons were investigated. The increased Mn substitution for Co or Mn substitution for Cu led into a higher secondorder magnetic phase transformation temperature, near 200 K in all ribbons. Under the field change of 7T, a maximum entropy change(Sm max) of 6 J kg^-1K^-1 was achieved in Gd(65)Cu10Co20Mn5 ribbon and slightly dependent on the compositions. With varied composition, a full width at half of Sm maxwas greatly widened to be over than 180 K for Gd65Cu15Co10Mn(10) ribbon. The refrigeration capacity was also greatly enhanced to 1000J kg^-1 for Gd65Cu20Co10Mn5 ribbon, which was even excellent compared with other Gd-based amorphous systems.

关键词： Phase transition Magnetocaloric effect Refrigeration capacity Amorphous ribbon Gd-based ribbon

A two-step method to apply Xu–Payne multi-porosity model to estimate pore type from seismic data for carbonate reservoirs

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Petroleum Science 2020年第3期17卷 615-627页

作者： Hong-Bing Li jia-jia Zhang sheng-Juan Cai Hao-Jie Pan Research Institute of Petroleum Exploration and Development Petrochina Company LimitedBeijing 100083China School of Geosciences China University of Petroleum(East China)Qingdao 266580China

Carbonate reservoirs exhibit strong heterogeneity in the distribution of pore types that can be quantitatively characterized by applying Xu–Payne multi-porosity ***,there are some prerequisites to this model the porosity and saturation need to be *** general,these application conditions are difficult to satisfy for seismic *** order to overcome this problem,we present a two-step method to estimate the porosity and saturation and pore type of carbonate reservoirs from seismic *** step one,the pore space of the carbonate reservoir is equivalent to a single-porosity system with an effective pore aspect ratio;then,a 3D rock-physics template(RPT)is established through the Gassmann’s equations and effective medium models;and then,the effective aspect ratio of pore,porosity and fluid saturation are simultaneously estimated from the seismic data based on 3D *** step two,the pore space of the carbonate reservoir is equivalent to a triple-porosity *** with the inverted porosity and saturation in the first step,the porosities of three pore types can be inverted from the seismic elastic *** application results indicate that our method can obtain accurate physical properties consistent with logging data and ensure the reliability of characterization of pore type.

关键词： Carbonate reservoirs Pore type Physical properties Rock-physics modeling Rock-physics inversion

Study of Carbon-poor Regions of Austenite during Bainitic Incubation Period by SAM

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Journal of Materials Science & Technology 1995年第5期11卷 353-357页

作者： WU, XL jia, HS ZHANG, XY kang, MK Northwestern Polytechnical Univ Xi'an China

The variation of carbon composition in undercooled austenite during bainitic incubation period has been investigated in 40CrMnSiMoVA by scanning auger microprobe (SAM). The results show that the outstanding diffusion and redistribution of carbon occur in isothermally reacted specimens. This leads to the formation of carbon-poor regions (CPR) near austenite grain boundaries and in austenite grains. The carbon content in CPR exceeds the equilibrium carbon composition of ferrite. Furthermore, it is indicated that the existence of CPR is thermodynamically possible.

关键词： Metallographic microstructure

Numerical Investigation of Residence Time Distribution for the Characterization of Groundwater Flow System in Three Dimensions

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Journal of Earth Science 2022年第6期33卷 1583-1600页

作者： jiale Wang Menggui Jin Baojie jia Fengxin kang Department of Soil and Water Conservation Changjiang River Scientific Research InstituteWuhan430010China School of Environmental Studies China University of GeosciencesWuhan430078China Research Center on Mountain Torrent and Geologic Disaster Prevention of MWR Wuhan430010China Wuhan Changjiang Science&Technology Development Co.Ltd. Wuhan430019China Shandong Provincial Bureau of Geology and Mineral Resources Jinan250013China

How to identify the nested structure of a three-dimensional(3D)hierarchical groundwater flow system is always a difficult problem puzzling hydrogeologists due to the multiple scales and complexity of the 3D flow *** main objective of this study was to develop a quantitative method to partition the nested groundwater flow system into different hierarchies in three dimensions.A 3D numerical model with topography derived from the real geomatic data in Jinan,China was implemented to simulate groundwater flow and residence time at the regional scale while the recharge rate,anisotropic permeability and hydrothermal effect being set as climatic and hydrogeological variables in the *** simulated groundwater residence time distribution showed a favorable consistency with the spatial distribution of flow *** probability density function of residence time with discontinuous segments indicated the discrete nature of time domain between different flow hierarchies,and it was used to partition the hierarchical flow system into shallow/intermediate/deep flow *** changes in the groundwater flow system can be quantitatively depicted by the climatic and hydrogeological *** study provides new insights and an efficient way to analyze groundwater circulation and evolution in three dimensions from the perspective of time domain.

关键词： groundwater flow residence time distribution 3D large-scale basin numerical modeling hydrology

Intravesical explosion during transurethral resection of bladder tumor:A case report

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World Journal of Clinical Cases 2022年第29期10卷 10689-10694页

作者： Chuan-Bing Xu Dong-sheng jia Zheng-sheng Pan Department of Urology Zibo Central HospitalZibo 255036Shandong ProvinceChina

BACKGROUND Intravesical explosion during transurethral resection of bladder tumor(TUR-BT)is a very rare complication,and it may result in rupture of the bladder,which usually requires surgical correction and causes a potential threat to the patient’s *** SUMMARY This paper reports a case of intravesical explosion during *** with the literature review,the risk factors are analyzed and measures of prevention and treatment are *** Although rare,intravesical explosions can cause serious consequences,and the loud explosion can also lead to a profound psychological shadow on the *** must be aware of this potential *** operative techniques and special precautions can reduce the risk of this complication.

关键词： Transurethral resection of bladder tumor Intravesical explosion Vesical rupture Case report

The Dynamics of a Bright-Bright Vector Soliton in Bose-Einstein Condensation

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Chinese Physics Letters 2012年第5期29卷 18-21页

作者： AN jia-Ren ZHOU Jie AO sheng-Mei Department of Physics Hunan Normal UniversityChangsha 410081

The dynamics of a bright-bright vector soliton in cigar-shaped Bose-Einstein condensate trapping in a harmonic potential is *** interaction between bright solitons in different species with small separation is *** the interaction between solitons of the same species,it is independent of the phase difference between the solitons,and may be of attraction or *** the former case,each soliton will oscillate about and pass through each other around the mass center of the system,which will also oscillate harmonically due to harmonic trapping potential.

关键词： harmonic soliton Einstein

Balancing Carbon Emission Reductions and Social Economic Development for Sustainable Development: Experience from 24 Countries

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Chinese Geographical Science 2020年第3期30卷 379-396页

作者： kang Meimei ZHAO Wenwu jia Lizhi LIU Yanxu State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal Univer-sityBeijing 100875China Institute of Land Surface System and Sustainable Development Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

The impact of human carbon emissions on climate has generated widespread global concern. We selected 24 countries as research objects and analysed the changes in carbon emissions in different countries between the establishment of emission reduction actions in 1990 and 2014. Then, we selected 19 factors representing four categories(economy, population, technology and energy) to explore the key factors that led to changes in carbon dioxide(CO2) emissions in different countries. Emission reduction actions since 1990 did not lead to marked improvements, and only five countries(Russia, Germany, the United Kingdom, Italy and France) achieved reductions in carbon emissions. The factors that influenced CO2 emissions varied among countries. In most developing countries, reductions in CO2 emissions were caused by reductions in poverty and inherent natural conditions. Moreover, the extent of influence of a given factor on CO2 emissions differed among countries. The global economic crisis may cause similar fluctuations in CO2 emissions in many countries. Adjustments to energy and industrial structures are the main reason for the reduction in carbon emissions, whereas economic growth and urbanization are the two major contributors to the growth of carbon emissions. According to historical carbon emissions data, a green energy revolution must be implemented to address global climate change and ensure the sustainable development of human societies.

关键词： carbon dioxide(CO2)emissions climate change economic growth sustainable development