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Scheduling piece requests blindly and randomly for peer-to-peer live streaming

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The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 76-84页

作者： CHEN Yi-shuai CHEN Chang-jia ZHAO Yong-xiang li chun-xi School of Electrical and Information Engineering Beijing Jiaotong University Beijing 100044 China

The design of piece scheduling algorithm is fundamental in mesh-based peer-to-peer （P2P） live streaming systems. This article regards the piece propagation process in P2P live streaming system as a conflict process, where peers compete to get the piece as soon as possible to meet the tight timing requirement of the live system. In this vision, the authors reduce the piece scheduling problem as a conflict resolution problem, and propose a blind random scheduling method to resolve it. The algorithm can be described as： 1） pieces are scheduled independently; 2） conflicts are resolved by the random back off algorithm. The theoretical analysis and simulation results prove that the algorithm scales well with the network size, and can obtain near-optimal in-time delivery of pieces. The algorithm is also easy to implement in the real-world system.

关键词： peer-to-peer live streaming conflict resolution exponential back off piece scheduling

Effects of long-term organic fertilization on soil microbiologic characteristics,yield and sustainable production of winter wheat

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Journal of Integrative Agriculture 2018年第1期17卷 210-219页

作者： li chun-xi MA Shou-chen SHAO Yun MA Shou-tian ZHANG ling-ling College of life Science Henan Normal University Field Scientific Observation and Research Base of Land Use Ministry of Land and Resources/Henan Polytechnic University

We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K （NPK） fertilizer was taken as the control （CK） and three organic fertilization treatments were used： NPK fertilizer＋pig manure （T1）, NPK fertilizer＋straw return （T2）, NPK fertilizer＋pig manure＋straw return （T3）. The results showed that all three organic fertilization treatments （T1, T2 and T3） significantly increased both soil total N （STN） and soil organic carbon （SOC） from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease （sucrase） and the soil respiration rate （SRS） for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon （SMBC） and microbial biomass nitrogen （SMBN）, the SMBC/SMBN ratio and the microbial quotient （qMB）. The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation （CV） of wheat yield and increased the sustainable yield index （SYI）. Wheat grain yield was significantly positively correlated with each of the soil microbial properties （P〈0.01）. These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.

关键词： winter wheat long-term organic fertilization soil microbial features yield stability yield sustainability

Effects of Root Pruning on Non-Hydraulic Root-Sourced Signal, Drought Tolerance and Water Use Efficiency of Winter Wheat

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Journal of Integrative Agriculture 2013年第6期12卷 989-998页

作者： MA Shou-chen li Feng-min YANG Shen-jiao li chun-xi XU Bing-cheng ZHANG Xu-cheng State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Ministry of Water Resources/Institute of Soil and Water Conservation Chinese Academy of Sciences School of Surveying and Land Information Engineering Henan Polytechnic University Key Laboratory of Efficient Utilization of Water in Dry Farming Gansu Province College of life Science Henan Normal University

Two pot experiments were conducted to study the effects of root pruning at the stem elongation stage on non-hydraulic root-sourced signals （nHRS）, drought tolerance and water use efficiency of winter wheat （Triticum aestivum）. The root pruning significantly reduced the root weight of wheat, but had no effect on root/shoot ratio at the two tested stages. At booting stage, specific root respiration of root pruned plants was significantly higher than those with intact roots （1.06 and 0.94 mmol g-1 s-1, respectively）. The soil water content （SWC） at which nHRS for root pruned plants appeared was higher and terminated lower than for intact root plants, the threshold range of nHRS was markedly greater for root pruned plants （61.1-44.6% field water capacity） than for intact root plants （57.9-46.1% field water capacity）. At flowering stage, while there was no significant difference in specific root respiration. The SWCs at which nHRS appeared and terminated were both higher for root pruned plants than for intact root plants. The values of chlorophyll fluorescence parameters, i.e., the effective photosystem II quantum yield （F PS II ）, the maximum photochemical efficiency of PS II （F v /F m ）, coefficient of photochemical quenching （qP）, and coefficient of non-photochemical quenching （NPQ）, in root pruned plants were significantly higher than in intact root plants, 7 d after withholding of water. Root pruned plants had significantly higher water use efficiency （WUE） than intact root plants in well-watered and medium drought soil, but not in severe drought condition. In addition, root pruning had no significant effect on grain yield in well-watered and medium drought soil, but significantly decreased grain yield in severe drought condition. In conclusion, the current study showed that root pruning significantly altered nHRS sensitivity and improved WUE of winter wheat in well-watered and medium drought soil, but lowered drought tolerance of winter wheat in severe drought soil

关键词： winter wheat root pruning non-hydraulic root-sourced signal (nHRS) root activity drought tolerance

Inferring playback rate and rate resets of P2P video streaming transmissions by piecewise line envelope approximation

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The Journal of China Universities of Posts and Telecommunications 2009年第2期16卷 58-62,79页

作者： li chun-xi CHEN Chang-jia School of Electronics and Information Engineering,Beijing Jiaotong University,Beijing 100044,China [a]School of Electronics and Information Engineering Beijing Jiaotong University Beijing 100044 China

Conventionally, P2P video is regarded as CBR traffic. However, our measurements have shown that the rate reset cannot be neglected in a practical IPTV system because each rate reset often leads to performance degradation. Thus, addressing the problem of inferring playback rate and rate reset in a P2P video system is significant. In this article, an algorithm termed piecewise linear envelope approximation （PLEA） is proposed, in which a follow-up time is introduced to smooth rate fluctuations in a small time scale and to adapt rate jumps in a large time scale automatically. With the PLEA algorithm, discontinuity introduced by blind segmentations adopted by current methods is avoided. Furthermore, unlike existing algorithms in which both segmentation and combinations are performed in multiple runs, only a single computation path is involved in the PLEA algorithm. This makes PLEA algorithm amenable to implementation of low complexity by either software or hardware. Both theoretical analysis and experiment based on measured data show that the PLEA outperforms existing algorithms based on segmentation.

关键词： P2P video playback rate rate reset convex hull linear program

Grain zinc and iron concentrations of Chinese wheat landraces and cultivars and their responses to foliar micronutrient applications

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Journal of Integrative Agriculture 2022年第2期21卷 532-541页

作者： JIANG li-na MA Jing-li WANG xiao-jie liU Gang-gang ZHU Zhao-long QI Chen-yang ZHANG ling-fang li chun-xi WANG Zhi-min HAO Bao-zhen College of life Sciences Henan Normal UniversityXinxiang 453007P.R.China chool of life Science and Basic Medicine Xinxiang UniversityXinxiang 453003P.R.China College of Agronomy China Agricultural UniversityBeijing 100193P.R.China

Grain zinc(Zn) and iron(Fe) concentrations and their responses to foliar application of micronutrients in 28 Chinese wheat landraces and 63 cultivars were investigated in a two-year field experiment. The average grain Zn and Fe concentrations were 41.8 mg kg^(-1)(29.0-63.3 mg kg^(-1)) and 39.7 mg kg^(-1)(27.9-67.0 mg kg^(-1)), respectively. Compared with cultivars, landraces had greater grain Zn(11.0%) and Fe(4.8%) concentrations but lower harvest index(HI), grain weight per spike(GWS), grain number per spike(GNS) and thousand grain weight(TGW). Both Zn and Fe concentrations were negatively and significantly correlated with HI, GWS, and GNS, while showed a poor association with TGW, suggesting that lower HI, GWS, and GNS, but not TGW, accounted for higher Zn and Fe concentrations for landraces than for cultivars. Grain Zn concentrations of both cultivars and landraces significantly increased after foliar Zn spray and the increase was two-fold greater for landraces(12.6 mg kg^(-1)) than for cultivars(6.4 mg kg^(-1)). Foliar Fe spray increased grain Fe concentrations of landraces(3.4 mg kg^(-1)) and cultivars(1.2 mg kg^(-1)), but these increases were not statistically significant. This study showed that Chinese wheat landraces had higher grain Zn and Fe concentrations than cultivars, and greater increases occurred in grain Zn concentration than in grain Fe concentration in response to fertilization, suggesting that Chinese wheat landraces could serve as a potential genetic source for enhancing grain mineral levels in modern wheat cultivars.

关键词： wheat cultivar landrace foliar application of micronutrients

Deciphering Water Oxidation Catalysts:The Dominant Role of Surface Chemistry over Reconstruction Degree in Activity Promotion

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Nano-Micro Letters 2025年第3期17卷 340-354页

作者： li An Jianyi li Yuanmiao Sun Jiamin Zhu Justin Zhu Yeow Seow Hong Zhang Nan Zhang Pinxian xi * Zhichuan JXu chun‑Hua Yan State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceFrontiers Science Center for Rare IsotopesCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000People’s Republic of China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Faculty of Materials Science and Energy Engineering Institute of Technology for Carbon NeutralityShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Key Laboratory of Electromagnetic Materials and Devices National Center for International Research On Photoelectric and Energy MaterialsSchool of Materials and EnergyElectron Microscopy CenterYunnan UniversityKunming 650091People’s Republic of China State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030People’s Republic of China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU‑HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871People’s Republic of China

Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution *** surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity ***,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is *** substituting Fe content influences both current change tendency and surface reconstruction ***_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)*** reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based ***,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term ***,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction *** effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface *** finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.

关键词： Oxygen evolution reaction Perovskite oxides Doping Activation and reconstruction

Relationships between high-molecular-weight glutenin subunit （HMW-GS）, pentosan and various component contents in different wheat varieties

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Journal of life Sciences 2007年第1期1卷 22-29,33页

作者： li chun-xi ZHANG Bei-bei SHAO Yun JIANG li-na li Dan-dan College of life Sciences Henan Normal University Xinxiang 453007 China

The composition of HMW-GS and pentosan and its various component contents in different wheat varieties were analyzed. According to scores of these subunits in several wheat varieties, the correlation relationship between the composition of HMW-GS, subunit combination types and pentosan, various components and component ratio were ascertained. The results showed that HMW-GSs were very diverse which had 11 types. In different varieties, the variation of Ara was obvious while Xyl was not; pentosan and its various component contents were very different, and their coefficient of variability was quite high. The majority of parameters had a significant negative correlation with Glu-1 where Glu-D1 was stronger than other two loci. N, 7, 17＋18 and 2＋12 subunits had influence on pentosan and its various component contents. But some subunits such as 1 and 5＋ 10 which are good for baking quality had little contribution to pentosan and various component contents. The pentosan and various component contents were higher in the varieties which had （N, 7, 2＋12） subunit combinations. Additionally, the 21 varieties were classified into 4 categories according to HMW-GS scores and pentosan content.

关键词： wheat HMW-GS pentosan correlation classification

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薄液滴在润湿性受限轨道上的热毛细迁移特性

物理学报 2023年第2期72卷 178-189页

作者：李春曦马成叶学民华北电力大学河北省低碳高效发电技术重点实验室保定071003

通过固体表面改性可对液滴热毛细迁移过程进行调控.基于润滑理论和滑移模型建立了均匀温度梯度作用下液滴在润湿性受限轨道上运动的数学模型,通过将基底划分成亲水区域和疏水区域构建了润湿性受限轨道.结合接触线动力学提出了三维液滴... 详细信息

通过固体表面改性可对液滴热毛细迁移过程进行调控.基于润滑理论和滑移模型建立了均匀温度梯度作用下液滴在润湿性受限轨道上运动的数学模型,通过将基底划分成亲水区域和疏水区域构建了润湿性受限轨道.结合接触线动力学提出了三维液滴在不同方向上接触线移动速度的计算方法,得到了液滴热毛细迁移的演化历程,分析了轨道宽度和润湿性对液滴迁移特性的影响.研究表明:液滴主体受温度梯度作用由高温区向低温区迁移,液滴后缘在移动过程中与主体部分间形成一层薄液膜,即薄液膜拖尾.液滴在垂直于轨道方向上的铺展受到抑制,收缩到轨道边缘后保持定扎状态.前进接触线移动速度开始时迅速减小,后缓慢降低趋于平稳;前进接触线移动速度与轨道宽度呈负相关.垂直于轨道方向上的壁面润湿性限制导致的排挤作用,在初始的短暂时刻对液滴在轨道上的热毛细迁移具有加速作用.液滴前进接触线移动速度与轨道润湿性呈正相关.增强轨道润湿性使得后退接触线移动速度的初始值增大,但对其稳定值影响不大.相比于改变轨道润湿性,改变轨道宽度更易于调控液滴热毛细迁移过程.

关键词：热毛细迁移润湿性液滴润滑理论

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接触角迟滞和气-液界面张力温度敏感性对液滴蒸发动态特性的影响

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物理学报 2021年第20期70卷 127-136页

作者：李春曦程冉叶学民华北电力大学动力工程系保定071003

基于润滑理论和滑移边界条件,构建了考虑接触角迟滞时液滴在均匀加热固体壁面上蒸发的数学模型,探讨了接触角迟滞对蒸发液滴动力学的影响,并分析了不同气-液界面张力温度敏感性的液滴蒸发特征.研究结果表明:接触角迟滞对液滴蒸发过程有... 详细信息

基于润滑理论和滑移边界条件,构建了考虑接触角迟滞时液滴在均匀加热固体壁面上蒸发的数学模型,探讨了接触角迟滞对蒸发液滴动力学的影响,并分析了不同气-液界面张力温度敏感性的液滴蒸发特征.研究结果表明:接触角迟滞对液滴蒸发过程有较大影响,随接触角迟滞增大,液滴的接触线钉扎时间延长,铺展阶段和去钉扎阶段时长缩短,液滴蒸发显著加快;迟滞角的增大使前进接触角增加,后退接触角减小,且后退接触角减小的幅度大于前进接触角增加的幅度.提高气-液界面张力对温度的敏感性系数可通过减小后退接触角,改善液滴在壁面上的润湿性,从而加强液滴传热,致使加快液滴蒸干.因此,改变接触角迟滞和气-液界面张力对温度的敏感性均可实现对液滴运动的调控,从而控制其蒸发进程.

关键词：液滴蒸发动力学特性接触角迟滞气-液界面张力温度敏感性