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Curvature notions on graphs

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Frontiers of Mathematics in China 2016年第5期11卷 1275-1290页

作者： Bobo HUA yong lin School of Mathematical Sciences LMNS Fudan University Shanghai 200433 China Shanghai Center for Mathematical Sciences Fudan University Shanghai 200433 China Department of Mathematics Renmin University of China Beijing 100872 China

We survey some geometric and analytic results under the assumptions of combinatorial curvature bounds for planar/semiplanar graphs and curvature dimension conditions for general graphs.

关键词： Planar graphs combinatorial curvature curvature dimension conditions harmonic functions

Equivalent Properties for CD Inequalities on Graphs with Unbounded Laplacians

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Chinese Annals of Mathematics,Series B 2017年第5期38卷 1059-1070页

作者： Chao GONG yong lin School of Information Renmin University of ChinaBeijing 100872China

The CD inequalities are introduced to imply the gradient estimate of Laplace operator on graphs. This article is based on the unbounded Laplacians, and finally concludes some equivalent properties of the CD(K,∞) and ... 详细信息

关键词： Graph theory CD inequality Unbounded Laplacian

WAVE-BODY INTERACTIONS FOR A SURFACE-PIERCING BODY IN WATER OF FINITE DEPTH

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Journal of Hydrodynamics 2010年第6期22卷 745-752页

作者： LI yong lin Mian Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

Nonlinear wave-body interactions for a stationary surface-piercing body in water of finite depth with fiat and sloping bottoms are simulated in a two-dimensional numerical wave tank, which is constructed mainly based on the spatially averaged Navier-Stokes equations with the k- ε model for simulating the turbulence. The equations are discretized based on the finite volume method and the scheme of the pressure implicit splitting of operators is employed to solve the Navier-Stokes equations. By using the force time histories, the mean and higher-harmonic force components are calculated. The computational results are shown to be in good agreement with experimental and numerical results of other researchers. Then, the horizontal force, the vertical force and the moment on the surface-piercing body under nonlinear regular waves with flat and sloping bottoms are obtained. The results indicate that the bottom topographies have a significant influence on the wave loads on the surface-piercing body.

关键词： wave-body interaction surface-piercing body numerical wave tank finite water depth

喷雾助剂对乙基多杀菌素药液在杧果叶片润湿铺展行为的影响

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热带作物学报 2025年第1期46卷 180-188页

作者：潘波王冰洁杜长远林勇姜蕾中国热带农业科学院环境与植物保护研究所海南海口571101 农业农村部热带作物有害生物综合治理重点实验室海南海口571101 华中农业大学植物科学技术学院湖北武汉430070

乙基多杀菌素是防治杧果蓟马的常用药剂之一,农药喷雾助剂的添加可以提高农药的药效。合理选择和使用助剂产品,对提高农药利用率、减少农药使用量至关重要。本研究通过测定添加5种不同类型、不同浓度的农药助剂产品后乙基多杀菌素药液... 详细信息

乙基多杀菌素是防治杧果蓟马的常用药剂之一,农药喷雾助剂的添加可以提高农药的药效。合理选择和使用助剂产品,对提高农药利用率、减少农药使用量至关重要。本研究通过测定添加5种不同类型、不同浓度的农药助剂产品后乙基多杀菌素药液的静态、动态表面张力,以及药液在杧果叶片正面、背面的接触角、铺展面积和蒸发时间,探究不同类型农药助剂产品在杧果叶片表面的润湿铺展行为。结果表明:添加不同助剂产品均能有效降低乙基多杀菌素药液的静态、动态表面张力,同时降低药液在叶片表面的接触角,提高药液在杧果叶片表面的铺展面积。除高分子类助剂(诺普信天盾)在叶片背面表现出抗蒸发性外,其他助剂产品均缩短了蒸发时间。不同类型的助剂产品在杧果叶片上的润湿性表现并不一致,有机硅类助剂(极润)润湿性最好,其余依次为硅酸金属复合盐类助剂(迈道)、改性植物油(迈飞)、橙皮精油(丹罗丰)、高分子类助剂(诺普信天盾)。通过比较不同处理组药液在杧果叶片正面、背面的润湿铺展行为,得出叶片背面比正面更难以被农药药液润湿。药液的理化性质和叶片的表面结构是影响喷雾液滴在叶片上润湿行为的重要因素。杧果蓟马常常在叶片背面活动取食,因此在防治杧果蓟马时,应根据助剂的类型、蓟马的为害特点选择合适的浓度,才能取得较好的防治效果。研究结果揭示了不同类型助剂在杧果叶片上的润湿铺展行为,为合理选择使用农药喷雾助剂产品提供数据支撑。

关键词：喷雾助剂表面张力接触角润湿面积干燥时间杧果

HARNACK AND MEAN VALUE INEQUALITIES ON GRAPHS

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Acta Mathematica Scientia 2018年第6期38卷 1751-1758页

作者： yong lin Hongye SONG Department of Mathematics Renmin University of China School of General Education Beijing International Studies University

We prove a Harnack inequality for positive harmonic functions on graphs whichis similar to a classical result of Yau on Riemannian manifolds. Also, we prove a mean valueinequality of nonnegative subharmonic functions ... 详细信息

关键词： harmonic function subharmonic function Harnack inequality mean valueinequality graph

Markov game for autonomic joint radio resource management in a multi-operator scenario

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 48-55页

作者： ZHANG yong-jing lin Yue-wei School of Telecommunication Engineering Beijing University of Posts andTelecommunications Beijing 100876 China

This article addresses the autonomy of joint radio resource management （JRRM） between heterogeneous radio access technologies（RATs） owned by multiple operators. By modeling the inter-operator competition as a general-sum Markov game, correlated-Q learning（CE-Q） is introduced to generate the operators＇ pricing and admission policies at the correlated equilibrium autonomically. The heterogeneity in terms of coverage, service suitability, and cell capacity amongst different RATs are considered in the input state space, which is generalized using multi-layer feed-forward neural networks for less memory requirement. Simulation results indicate that the proposed algorithm can produce rational JRRM polices for each network under different load conditions through the autonomic learning process. Such policies guide the traffic toward an optimized distribution and improved resource utilization, which results in the highest network profits and lowest blocking probability compared to other self-learning algorithms.

关键词： autonomic JRRM multi-operator reinforcement learning (RL) Markov game

Interstitial Solution Carbon Concentration and Defects of Ti+Nb ULC-BH Steel by Internal Friction and Positron Annihilation Methods

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Journal of Iron and Steel Research International 2014年第1期21卷 91-97页

作者： Ji-ping CHEN yong-lin KANG School of Metallurgical Engineering Key Laboratory of Metals and Processing of Anhui Province Anhui University of Technology School of Materials Science and Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology Beijing

The interstitial solution carbon concentration and defects in continuously annealed Ti＋Nb bearing ULC- BH （ultra-low carbon bake hardening） steel samples are investigated by multi-functional internal friction apparatus, positron annihilation lifetime spectroscopy （PALS） and coincidence Doppler broadening spectroscopy （CDBS）. The relationship of internal friction peaks, interstitial solution carbon concentrations and movable dislocations in the sam- ples under different conditions is analyzed. A correlation of lifetime component v~ values with interstitial solution car- bon concentrations in the samples for different continuous annealing processes is established, while a correlation of li- fetime component r2 values with multi-vacancies, vacancy clusters, microvoids and other types of defects for various continuous annealing processes is also demonstrated. Furthermore, the average lifetime results illustrate the overall defect densities for various continuous annealing processes. The CDBS analysis reflects the chemical surroundings of the defects at the annihilation sites and reveals that the peak heights of the ratio curves relate to the total number of defects such as interstitial carbon atoms, dislocations, vacancies and other types of defects. The results show that in- ternal friction, PALS and CDBS are effective techniques to identify and characterize the interstitial solution carbon concentration, multi-vacancies, vacancy clusters, microvoids and other types of microscopic defects in annealed Ti＋ Nb bearing ULC-BH steel.

关键词： ULC-BH steels internal frictions positron annihilation lifetimes coincidence Doppler broadening

Influence of coating and dew point on hearth roll pickup

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Journal of Iron and Steel Research International 2019年第6期26卷 647-652页

作者： Xiao-fei Zheng yong-lin Kang Jian Zhou School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Shougang Jingtang Iron and Steel United Co. Ltd. Tangshan 063200 Hebei China

Thermal spray coatings have been widely used on hearth rolls in a continuous annealing line to improve steel sheet quality and prolong the roll service life. One of the common defects formed on a working hearth roll is the oxide pickup. The most common cause of the pickup formation is that the active Mn oxide reacts with coating. The potentials of two different coatings, CoCrAlYTa-Al2O3 (No. 1) and CoCrYNi-Y2O3 (No. 2), to duplicate pickups by reacting with Fe and Mn oxides were studied. There are three stages during pickup producing and growing. No. 2 coating effectively reduced the corrosion of Mn oxide. The characterization and modification of the surface oxide formed can be changed with different dew points. The results indicate that the dew point from — 53 to — 10 ℃ can change the depth of Mn oxide, such that an alteration can prevent the first stage and second stage and is good for preventing the pickup growing.

关键词： Pickup Coating Dew point Surface oxide Hearth roll

Conservation Laws of a Class of Combined Equations

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Communications in Theoretical Physics 2009年第1期51卷 35-38页

作者： ZHANG Zhi-yong yong Xue-lin CHEN Yu-Fu School of Mathematical Sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Mathematics and Physics North China Electronic Power University Beijing 102206 China

In this paper, we investigate conservation laws of a class of partial differential equations, which combines the nonlinear telegraph equations and the nonlinear diffusion-convection equations. Moreover, some special conservation laws of the combined equations are obtained by means of symmetry classifications of wave equations uxx = H （x）utt.

关键词： symmetry conservation law multiplier differential characteristic set