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NUMERICAl PREDICTION OF lINE BUOYANT JETS IN CROSS FlOWS

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Journal of Hydrodynamics 2001年第1期13卷 12-16页

作者： han, H.l. li, W. Sch. of Urban and Rural Construction Hebei Agriculture Univ. Baoding 071001 China

The k-Ε turbulence model was used to establish the mathematical model of two-dimensional line buoyant jets in crossflow. The hybrid finite analytic method and staggered grid were applied to the calculation of line buoyant jets. Only receiving water with uniform density is considered. The distribution of velocity, temperature and turbulent kinetic energy were analyzed, and the variation of the maximum velocity was given. The effect of velocity ratio and densimetric Froude number on line buoyant jets was considered.

关键词： Computational fluid dynamics Computer simulation Diffusers (fluid) Mathematical models Numerical methods

A Diagnostic Analysis on the Effect of the Residual layer in Convective Boundary layer Development near Mongolia Using 20th Century Reanalysis Data

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Advances in Atmospheric Sciences 2015年第6期32卷 807-820页

作者： han Bo ZHAO Cailing l Shihua WANG Xin key laboratory of land Surface Process and Climate Change in Cold and Arid Regions Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Although the residual layer has already been noted in the classical diurnal cycle of the atmospheric boundary layer, its effect on the development of the convective boundary layer has not been well studied. In this study, based on 3-hourly 20th century reanalysis data, the residual layer is considered as a common layer capping the convective boundary layer. It is identified dally by investigating the development of the convective boundary layer. The region of interest is bounded by （30^-60~N, 80^-120~E）, where a residual layer deeper than 2000 m has been reported using radiosondes. The lapse rate and wind shear within the residual layer are compared with the surface sensible heat flux by investigating their climatological means, interannual variations and daily variations. The lapse rate of the residual layer and the convective boundary layer depth correspond well in their seasonal variations and climatological mean patterns. On the interannual scale, the correlation coefficient between their regional averaged （40°-50°N, 90°-110°E） variations is higher than that between the surface sensible heat flux and convective boundary layer depth. On the daily scale, the correlation between the lapse rate and the convective boundary layer depth in most months is still statistically significant during 1970-2012. Therefore, we suggest that the existence of a deep neutral residual layer is crucial to the formation of a deep convective boundary layer near the Mongolian regions.

关键词： convective boundary layer residual layer lapse rate surface sensible heat flux wind shear

Development of the Convective Boundary layer Capping with a Thick Neutral layer in Badanjilin:Observations and Simulations

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Advances in Atmospheric Sciences 2012年第1期29卷 177-192页

作者： han Bo lÜShihua AO Yinhuan Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of SciencesNo.320Donggang West RoadLanzhou 730000

In this study, the development of a convective boundary layer （CBl） in the Badaujilin region was investigated by comparing the observation data of two cases. A deep neutral layer capped a CBl that occurred on 30 August 2009. This case was divided into five sublayers from the surface to higher atmospheric elevations： surface layer, mixed layer, inversion layer, neutral layer, and sub-inversion layer. The development process of the CBl was divided into three stages： S1, S2, and S3. This case was quite different from the development of the three-layer CBl observed on 31 August 2009 because the mixed layer of the five-layer CBl （CBl5） eroded the neutral layer during S2. The specific initial structure of the CBl5 was correlated to the synoptic background of atmosphere during nighttime. The three-stage development process of the CBl5 was confirmed by six simulations using National Center for Atmospheric Research （USA） large-eddy simulation （NCAR-lES）, and some of its characteristics are presented in detail.

关键词： convective boundary layer neutral layer large-scale circulation large-eddy simulation

Novel medium entropy perovskite oxide Sr(FeCoNiMo)_(1/4)O_(3−δ)for zinc-air battery cathode

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Journal of Energy Chemistry 2024年第9期96卷 669-678页

作者： kaixin li Juntao Gao Xu han Qi Shao Zhe lü School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Heilongjiang Provincial key laboratory of Advanced Quantum Functional Materials and Sensor Components Harbin 150001HeilongjiangChina

It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxides often involves introducing multiple elements with different properties,thereby providing outstanding bifunctional catalytic activity for OER/***,the possible underlying catalytic pathways and potential interactions between various components are still poorly *** paper presents an excellent medium-entropy perovskite oxide,Sr(FeCoNiMo)_(1/4)O_(3−δ)(lower overpotential of 301 mV at 10 mA cm^(−2)).Zinc-air batteries employing it as a cathode catalyst demonstrate excellent round-trip efficiency(62%).By combining theoretical calculation with experiments,we aim to establish the link between the electronic structure of perovskite oxides with different elemental compositions and their OER *** reveals that the conformational entropy strategy can simultaneously shift the O 2p-band center and metal d-band center of perovskite oxide towards the vicinity of the Fermi energy level,thereby triggering a more favorable lattice oxygen-participated mechanism(lOM)during the OER *** outcomes of this work provide crucial insights into the role of conformational entropy strategies in oxygen catalysis and offer potential avenues for constructing efficient and stable electrocatalysts.

关键词： Sr(FeCoNiMo)_(1/4)O_(3−δ) Bifunctional catalyst Medium entropy lOM Rechargeable zinc-air batteries

The combined effects of grain and sample sizes on the mechanical properties and fracture modes of gold microwires

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Journal of Materials Science & Technology 2019年第1期35卷 76-83页

作者： H.k.Yang k.Cao Y.han M.Wen J.M.Guo Z.l.Tan J.lu Y.lu Hong kong Branch of National Precious Metals Material Engineering Research Center City University of Hong Kong Department of Mechanical and Biomedical Engineering City University of Hong Kong State key laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-platinum Metals Co.Ltd Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research Institute

Hall-Petch relation was widely applied to evaluate the grain size effect on mechanical properties of metallic material. However, the sample size effect on the Hall-Petch relation was always ignored. In the present study, the mechanical test and microstructure observation were performed to investigate the combined effects of grain and sample sizes on the deformation behaviors of gold microwires. The polycrystalline gold microwires with diameter of 16 ?m were annealed at temperatures from 100°C to 600°C, leading to different ratios(t/d) of wire diameter(t) to grain size(d) from 0.9 to 16.7. When the t/d was lower than 10, the yield stress dropped fast and deviated from the Hall-Petch relation. The free-surface grains played key role in the yield stress softening, and the volume fraction of free-surface grains increased with the t/d decreasing. Furthermore, the effects of t/d on work-hardening behaviors and fracture modes were also studied. With t/d value decreasing from 17 to 3.4, the samples exhibited necking fracture and the dislocation pile-ups induced work-hardening stage was gradually *** the t/d value further decreasing(t/d lure, and the work-hardening capability lost. As the gold microwire for wire bonding is commonly applied in the packaging of integrated circuit chips, and the fabrication of microwire suffers multi-pass cold-drawing and annealing treatments to control the grain size. The present study could provide instructive suggestion for gold microwire fabrication and bonding processes.

关键词： Gold microwire Wire bonding Tensile testing Grain size Hall-Petch relationship

Frozen landweber Iteration for Nonlinear Ill-Posed Problems

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Acta Mathematicae Applicatae Sinica 2007年第2期23卷 329-336页

作者： J.Xu B.han l.li Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100080China Department of Mathematics Harbin Institute of TechnologyHarbin 150001China

In this paper we propose a modification of the landweber iteration termed frozen landweber iteration for nonlinear ill-posed problems. A convergence analysis for this iteration is presented. The numerical performance of this frozen landweber iteration for a nonlinear Hammerstein integral equation is compared with that of the landweber iteration. We obtain a shorter running time of the frozen landweber iteration based on the same convergence accuracy.

关键词： Ill-posed problem regularization landweber iteration

Application of Gaussian Beam Summation Migration in Reflected In-seam Wave Imaging

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 276-284页

作者： han Jianguang lÜQingtian ZhanG Zhiheng YANG Shun WANG Shuo Chinese Academy of Geological Sciences Beijing 100037China Shandong Taishan Resources Exploration Co. Ltd.Jinan 250104China

The geological conditions for coal mining in China are complex,with various structural issues such as faults and collapsed columns seriously compromising the safety of coal mine ***-seam wave exploration is an effective technique for acquiring detailed information on geological structures in coal seam working ***,the existing reflected in-seam wave imaging technique can no longer meet the exploration precision requirements,making it imperative to develop a new reflected in-seam wave imaging *** study applies the Gaussian beam summation(GBS)migration method to imaging coal seams'reflected in-seam wave ***,with regard to the characteristics of the reflected in-seam wave data,methods such as wavefield removal and enveloped superposition are employed for the corresponding wavefield separation,wave train compression and other processing of reflected in-seam ***,imaging is performed using the GBS migration *** feasibility and effectiveness of the proposed method for reflected in-seam wave imaging are validated by conducting GBS migration tests on 3D coal-seam fault models with different dip angles and *** applying the method to reflected in-seam wave data for an actual coal seam working face,accurate imaging of a fault structure is obtained,thereby validating its practicality.

关键词： reflected in-seam wave Gaussian beam summation migration numerical tests fault

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西安地区犬和猫肿瘤流行现状与防治对策

动物医学进展 2025年第1期46卷 128-134页

作者：白佳秀吕子颖段学鹏韩永荣郭抗抗吕长荣西北农林科技大学动物医学院陕西杨凌712100 海南大学热带农林学院海南海口570228 西北农林科大西安动物医院陕西西安710065

通过对西北农林科大西安动物医院4年7个月共收治的西安地区7399例(犬4813例,猫2586例)犬和猫病例中308例肿瘤的分析,发现犬、猫肿瘤发病率分别为5.96%和0.81%;最常发的肿瘤有乳腺肿瘤、恶性淋巴瘤、脂肪瘤、肥大细胞瘤与肛周腺瘤。犬发... 详细信息

通过对西北农林科大西安动物医院4年7个月共收治的西安地区7399例(犬4813例,猫2586例)犬和猫病例中308例肿瘤的分析,发现犬、猫肿瘤发病率分别为5.96%和0.81%;最常发的肿瘤有乳腺肿瘤、恶性淋巴瘤、脂肪瘤、肥大细胞瘤与肛周腺瘤。犬发病品种以贵宾犬、牧羊犬与金毛犬居多,分别占24.64%、12.56%和11.59%;小型犬发病率最高,占51.57%。老龄犬多发,但9岁以下犬发病率也高达33.45%。发病季节集中在冬春季节。发病部位以乳腺和皮肤最多,分别占29.27%和21.95%。雌性犬、猫发病率分别为58.19%和42.86%,雄性犬、猫发病率分别为41.81%和57.14%;未绝育雌性犬、猫更易发生乳腺肿瘤与泌尿生殖道肿瘤,未去势雄性犬、猫更易发生肛周肿瘤。组织活检与组织病理学结果显示良性肿瘤占58.51%,恶性肿瘤占41.49%。

关键词：肿瘤犬猫流行现状防治对策

MEChanISM AND kINETICS OF TRANSFORMATION OF AlUMINA INClUSIONS BY CAlCIUM TREATMENT

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Acta Metallurgica Sinica(English letters) 2006年第1期19卷 1-8页

作者： Z.J. han l. liu M. lind l. Holappa Central Iron and Steel Research Institute Beijing 100081 China laboratory of Metallurgy Helsinki University of Technology P.O. Box 6200Espoo 02015 Finland

The basic mechanism and kinetics of the transformation process of alumina inclusions in steel was reported when calcium introduced into the steel by wire feeding orpowder injection. To clarify the mechanisms model, experiments were performed by studying reactions between AltOs and CaO in a laboratory furnace and by performing calcium treatments in an 8kg induction furnace for Al deoxidised melt. The phases formed during the reaction between Al2O3 and CaO were examined by SEM-EDS （scanning electron microscope-energy dispersive spectrometer）, and the reaction sequence of Al2O3=〉 CA6=〉 CA2 =〉 CA =〉 CAx（l） was discussed in term of the experimental observations. The kinetics of the reaction of calcium with alumina inclusions were simulated by immersing alumina plates in a Ca treated steel melt in the induction furnace. Results were compared with observations of real inclusion transformation. A kinetic model was proposed based on the results.

关键词： mechanism kinetics alumina inclusion transformation