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A compressing and saving method for structured grid data based on block construction

Chinese Journal of Aeronautics 2022年第6期35卷 146-155页

作者： Yan sun ying ZHAO Dehong MENG Meng JIANG State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000China Computational Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

The increasing grid data in CFD simulation has brought some new difficulties and challenges,such as high storage cost,low transmission *** order to overcome these problems,a novel method for compressing and saving the structured grid are *** the present method,the geometric coordinates of the six logical domains of one grid block is saved instead of all grid vertex coordinates to reduce the size of the structured grid file when the grid is *** all grid vertex coordinates are recovered from the compressed data with the use of the transfinite interpolation algorithm when the grid is ***,single-block grid cases with different edge vertexes are tested to investigate the compression *** test results show that a higher compression ratio will be obtained on a larger ***,further theoretical analysis is carried out to investigate the effects of parameters on grid *** analysis on single-block grid compression shows that the compression ratio is proportionate to the cubic root of the number of total *** highest compression ratio of single-block grid is obtained when the numbers of vertexes in three logical directions are *** analysis on multi-block grid compression shows that a higher compression ratio will be obtained when a larger difference of total vertexes number exists among the grid ***,multi-blockgrids of two industrial aircraft configurations are compressed to validate the *** compression results demonstrate that the present method has an excellent ability on structured grid *** a million-vertex structured grid,more than 80 percent disk space can be saved after compression.

关键词： CFD Compression Compression ratio Structured grid Transfinite interpolation

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A novel compound data classification method and its application in fault diagnosis of rolling bearings

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International Journal of Intelligent Computing and Cybernetics 2017年第1期10卷 80-90页

作者： Anxin sun ying Che College of Optical and Electronic Information Changchun University of Science and TechnologyChangchunChina

Purpose-The purpose of this paper is to provide a fault diagnosis method for rolling *** bearings are widely used in industrial appliances,and their fault diagnosis is of great importance and has drawn more and more *** on the common failure mechanism of failure modes of rolling bearings,this paper proposes a novel compound data classification method based on the discrete wavelet transform and the support vector machine(SVM)and applies it in the fault diagnosis of rolling ***/methodology/approach-Vibration signal contains large quantity of information of bearing status and this paper uses various types of wavelet base functions to perform discrete wavelet transform of vibration and *** vectors are constructed based on several time-domain indices of the denoised *** is then used to perform classification and fault *** the optimal wavelet base function is determined based on the diagnosis ***-Experiments of fault diagnosis of rolling bearings are carried out and wavelet functions in several wavelet families were *** results show that the SVM classifier with the db4 wavelet base function in the db wavelet family has the best fault diagnosis ***/value-This method provides a practical candidate for the fault diagnosis of rolling bearings in the industrial applications.

关键词： Support vector machine Fault diagnosis Data classification Discrete wavelet transform Rolling bearing

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Absorption-dominant EMI shielding performance of multiple folded bi_(2)Se_(3)/PVDF nanocomposite films

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Journal of Materiomics 2024年第1期10卷 27-36页

作者： Xinyi Pu Zunpeng Feng Siyuan sun Ke bi Yanan Hao State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing100876China Chinese Academy of Engineering Innovation Strategy Beijing100088China

Absorption-dominant electromagnetic interference(EMI)shielding materials are promising in reducing electromagnetic radiation pollution,but their preparation processes are usually difficult and unsuitable for large-scale *** this work,multiple folded bi_(2)Se_(3)/PVDF nanocomposite films were fabri-cated by using a convenient tape-casting method and multiple folding,which can be easily extended in industrial *** EMI shielding effectiveness(SE)of the composite materials was investigated,which shows typical absorption-dominant behavior and can substantially reduce secondary ***,for the 35%(in volume)bi_(2)Se_(3)/PVDF nanocomposite film,the SE_(A)of single-layered film with a thickness of 60 mm reaches 20 dB while SE_(R)is lower than 5 *** folding the film into eight layers,the SE_(A)increased to 50 dB while SE_(R)remains below 5 *** method provides an effective way to the fabrication of absorption-dominant electromagnetic absorption(EMA)and EMI shielding material.

关键词： Electromagnetic interference shielding(EMI) Electromagnetic wave absorption bismuth selenide Composite

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Structural Characteristics and Influencing Factors of Carbon Emission Spatial Association Network:A Case Study of Yangtze River Delta City Cluster,China

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Chinese Geographical Science 2024年第4期34卷 689-705页

作者： bi Xi sun Renjin HU Dongou SHI Hongling ZHANG Han School of Economics and Management China University of Petroleum(Beijing)Beijing 102249China China Petroleum Planning&Engineering Institute Beijing 100083China

City cluster is an effective platform for encouraging regionally coordinated *** reduction of carbon emissions within city cluster via the spatial association network between cities can help coordinate the regional carbon emission management,realize sustainable development,and assist China in achieving the carbon peaking and carbon neutrality *** paper applies the improved gravity model and social network analysis(SNA)to the study of spatial correlation of carbon emissions in city clusters and analyzes the structural characteristics of the spatial correlation network of carbon emissions in the Yangtze River Delta(YRD)city cluster in China and its influencing *** results demonstrate that:1)the spatial association of carbon emissions in the YRD city cluster exhibits a typical and complex multi-threaded network *** network association number and density show an upward trend,indicating closer spatial association between cities,but their values remain generally ***,the network hierarchy and network efficiency show a downward trend but remain high.2)The spatial association network of carbon emissions in the YRD city cluster shows an obvious‘core-edge’distribution *** network is centered around Shanghai,Suzhou and Wuxi,all of which play the role of‘bridges’,while cities such as Zhoushan,Ma'anshan,Tongling and other cities characterized by the remote location,single transportation mode or lower economic level are positioned at the edge of the network.3)Geographic proximity,varying levels of economic development,different industrial structures,degrees of urbanization,levels of technological innovation,energy intensities and environmental regulation are important influencing factors on the spatial association of within the YRD city ***,policy implications are provided from four aspects:government macro-control and market mechanism guidance,structural characteristics of the‘core-edge’network,reconfigura

关键词： carbon emission spatial association network social network analysis(SNA) quadratic assignment procedure(QAP)model Yangtze River Delta city cluster China

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Preliminary evidence in treatment of eosinophilic gastroenteritis in children:A case series

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World Journal of Clinical Cases 2022年第19期10卷 6417-6427页

作者： ying Chen Mei sun Department of Pediatric Gastroenterology Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

BACKGROUND Eosinophilic gastroenteritis is a rare inflammatory disorder in ***,there is still no standard guideline in the treatment of pediatric eosinophilic *** To report our experience with the diagnosis and treatment of children with eosinophilic *** From January 2017 to December 2019,a total of 22 children were diagnosed with eosinophilic *** Endoscopic examination showed eosinophil infiltration in the duodenum[mean number of eosinophils/high-power field(HPF)=53.1±81.5],stomach(mean number of eosinophils/HPF=36.8±50.5),and terminal ileum(mean number of eosinophils/HPF=49.0±24.0).All 18 children with low eosinophil infiltration(14%)relapsed after initial methylprednisolone/montelukast *** addition,children with high eosinophil infiltration(>14%)showed symptomatic relief and histological remission without further relapse after receiving budesonide/methylprednisolone as initial or relapse *** Methylprednisolone/montelukast is still the best treatment for children with low eosinophil infiltration(14%).

关键词： Eosinophil gastroenteritis Children Budesonide Methylprednisolone Montelukast Absolute eosinophil count

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Long-term trend analysis of wave characteristics in the Bohai Sea based on interpolated ERA5 wave reanalysis from 1950 to 2020

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Acta Oceanologica Sinica 2022年第7期41卷 97-112页

作者： Jichao Wang Peidong sun Zhihong Liao Fan bi Guiyan Liu College of Science China University of PetroleumQingdao266580China National Meteorological Information Center Beijing100081China North China Sea Marine Forecasting Center of State Oceanic Administration Qingdao266061China Shandong Provincial Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao266061China

Reasonably understanding of the long-term wave characteristics is very crucial for the ocean engineering.A feedforward neural network is operated for interpolating ERA5 wave reanalysis in this study,which embodies a detailed record from 1950 *** spatiotemporal variability of wave parameters in the Bohai Sea,especially the significant wave height(SWH),is presented in terms of combined wave,wind wave and swell by employing the 71 years(1950–2020)of interpolated ERA5 *** mean SWH decreases at−0.12 cm/a estimated by Theil-Sen estimator and 95th percentile SWH reflecting serve sea states decreases at−0.20 cm/***-seasonal analysis shows SWH of wind wave has steeper decreasing trend with higher slopes than that of swell,especially in summer and winter,showing the major decrease may attribute to the weakening of *** inner Bohai Sea reveals a general decreasing trend while the intersection connecting with the Yellow Sea has the lower significance derived by Mann-Kendall ***,95th percentile SWH decreases at a higher rate while with a lower significance in comparison with the mean *** frequencies of mean wave directions in sub-sector are statistically calculated to find the seasonal prevailing ***,the dominant directions in summer and winter are south and north.A similar variation concerning to SWH,the trend of the mean wave period is provided,which also shows a decrease for decades.

关键词： wave characteristic wind wave swell long-term trend Bohai Sea

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Grain boundary segregation and relaxation in nano-grained polycrystalline alloys

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 72-90页

作者： Tong-Yi Zhang ying-Xin Gao Sheng sun Materials Genome Institute Shanghai UniversityShanghai200444China

The present study carries out systematic thermodynamics analysis of Grain Boundary(GB)segregation and relaxation in NanoGrained(NG)polycrystalline *** segregation and relaxation is an internal process towards thermodynamic equilibrium,which occurs naturally in NG alloys without any applied loads,causes deformation and generates internal *** analysis comprehensively investigates the multiple coupling effects among chemical concentrations and mechanical stresses in GBs and grains.A hybrid approach of eigenstress and eigenstrain is developed herein to solve the multiple coupling *** analysis results indicate that the GB stress and grain stress induced by GB segregation and relaxation can be extremely high in NG alloys,reaching the GPa level,which play an important role in the thermal stability of NG alloys,especially via the coupling terms between stress and *** present theoretic analysis proposes a novel criterion of thermal stability for NG alloys,which is determined by the difference in molar free energy between a NG alloy and its reference single crystal with the same nominal chemical *** the difference at a temperature is negative or zero,the NG alloy is thermal stable at that temperature,otherwise unstable.

关键词： nano-grained alloys thermal stability grain boundary segregation eigenstress eigenstrain

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Highly efficient extraction of lithium from salt lake brine by LiAl-layered double hydroxides as lithium-ion-selective capturing material

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Journal of Energy Chemistry 2019年第7期28卷 80-87页

作者： ying sun Xiaoyu Guo Shaofang Hu Xu Xiang State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

The extraction of lithium from salt lake brine in the Chinese Qaidam Basin is challenging due to its high Mg/Li and Na/Li ratios. Herein, we utilized a reaction-coupled separation technology to separate sodium and lithium ions from a high Na/Li ratio brine(Na/Li = 48.7, w/w) and extracted lithium with Li Al-layered double hydroxides(Li Al-LDHs). The Li Al-LDHs act as lithium-ion-selective capturing materials from multication brines. That is, the lithium ions selectively enter the solid phase to form Li Al-LDHs, and the sodium ions are still retained in the liquid phase. This is because the lithium ions can be incorporated into the structural vacancies of LiAl-LDHs, whereas the sodium ions cannot. The effects of reaction conditions on lithium loss and separation efficiency were investigated at both the nucleation and the crystallization stage, e.g., the nucleation rotating speed, the Li/Al molar ratio, the crystallization temperature and time, and co-existing cations. The lithium loss is as low as 3.93% under optimal separation *** sodium ions remained in the solution. Consequently, an excellent Na/Li separation efficiency was achieved by this reaction-coupled separation technology. These findings confirm that LiAl-LDHs play a critical function in selectively capturing lithium ions from brines with a high Na/Li ratio, which is useful for the extraction of lithium ions from the abundant salt lake brine resources in China.

关键词： LiAl-LDHs Lithium extraction Energy metal Salt lake brine Reaction-coupled separation technology

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Defluorination of bastnaesite by steam roasting process

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Journal of Rare Earths 2022年第12期40卷 1963-1968,I0006页

作者： Shuchen sun ying Yang Ganfeng Tu Faxin Xiao School of Metallurgy Northeastern UniversityShenyang 110819China College of Chemical Engineering Shenyang University of Chemical TechnologyShenyang 110142China

The bastnaesite was defluorinated by steam roasting process,and fluorine was removed in the form of hydrogen fluoride to realize the separation from rare *** effects of particle size of raw material,roasting temperature and time on defluorination rate of bastnaesite were *** suitable conditions of steam roasting process are that the particle size of raw material is less than 74μm,the roasting temperature is 1000℃and the roasting time is 4 *** defluorination rate of bastnaesite is close to 100%under above these *** the temperature rises to 1000℃,the voids on the surface of the particles increase obviously,and there is a developed network of voids,which indicates that the fluorine oxides in bastnaesite react fully with the saturated water vapor at this stage,and a large amount of fluorine escapes in the form of hydrogen fluoride from the surface and inside of the mineral.X-ray diffraction results show that there are only rare-earth oxides in the form of Ce_(0.33)La_(0.33)Ca_(0.33)O_(1.5)and Ce_(7)O_(12)in the *** results of energy spectra and chemical analysis show that the fluorine in the baking sand was basically completely removed.

关键词： Bastnaesite Roasting Steam decomposition Defluorination reaction Defluorination rate Rare earths

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Synthesis of granulated Li_(1.33)Mn_(1.67)O_(4) via two antisolvent methods for lithium adsorption from gas-produced water

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Chinese Journal of Chemical Engineering 2024年第5期69卷 34-46页

作者： Jun Qiu Lu-Ri Bao Wei Guo ying Yang Shu-ying sun National Engineering Research Center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China

Gas-produced water is an accompanying wastewater in the natural gas extraction process,and it is a potential liquid lithium resource that contains a considerable amount of *** study investigated the feasibility of using manganese-based ion sieves to adsorb and extract lithium from gas-produced *** we focused on the applicability of two different granulation methods,extrusion and droplet,in gas-produced water *** types of H_(1.33)Mn_(1.67)O_(4) particles were prepared by the extrusion method(EHMO)and the droplet method(DHMO).The porosity of DHMO was much higher than that of EHMO,and the adsorption performance of DHMO increased with the decrease of binder *** prepared with a binder concentration of 0.14 g·ml^(-1)exhibited the best adsorption performance in gas-produced water,and the Li^(+)adsorption capacity could reach 25.14 mg·g^(-1).In gas-produced water,the adsorption equilibrium of DHMO only took 9 h,and the adsorption process conformed to the Langmuir model and pseudo-second-order kinetic *** pore diffusion model(PDM)could well describe its adsorption ***,DHMO showed a great selectivity to Li^(+),and the selectivity order of DHMO in gas-produced water was Li^(+)>Ba^(2+)>>Mg^(2+),Ca^(2+),Sr^(2+)>>Na^(+)>>K^(+).After 20 cycles,the Li^(+)adsorption capacity was still higher than 17.30 mg·g^(-1),and the rate of manganese dissolution was less than 1%.

关键词： Gas-produced water Granulation Li_(1.33)Mn_(1.67)O_(4)

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