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一种基于卷积码的网络丢包恢复新方法

通信学报 2002年第3期23卷 21-26页

作者：彭波韦岗华南理工大学电子与信息学院广东广州510640

本文提出了一种基于(2.1,m)卷积码的网络丢包错误恢复新方法,给出了(2.1,m)系统卷积码的纠删解码算法和解码判定定理,并证明了最优列距离剖面码具有最优延迟特性。实验结果证明本方法可以在不同的解码延迟条件下保持良好的效果,从而能... 详细信息

本文提出了一种基于(2.1,m)卷积码的网络丢包错误恢复新方法,给出了(2.1,m)系统卷积码的纠删解码算法和解码判定定理,并证明了最优列距离剖面码具有最优延迟特性。实验结果证明本方法可以在不同的解码延迟条件下保持良好的效果,从而能适应不同的网络延迟条件。

关键词：卷积码包丢失纠删码

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Using Good Nodes Set Principle to Evolution Strategy for Constrained Optimization

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Using Good Nodes Set Principle to Evolution Strategy for Con...

第二十六届中国控制会议

作者： Xiao Chixin1,2.Cai Zixing1 1.School of Information Science and engineering,Central South university,Changsha 410083,P.R.{2. 2.Information engineering college,Xiangtan university,Xiangtan 411105,P.R.{2.

Incorporating orthogonal design to enhance the crossover operator of the evolution strategy（ES）can make the re-sulting evolutionary algorithm more robust and statically *** its precision is restricted by dimension of search *** nodes set（GNS）is a concept in number *** paper presents a new evolution strategy that effectively combines GNS principle with crossover operator to handle constrained optimization problems（COPs）.The proposed method has achieved the same sound results as the orthogonal method does,but not to be restricted by the dimension of the *** simplex selected and diversity mechanism is used to enrich the exploration and exploitation abilities of the approach *** results on a set of benchmark problems show the efficiency of the algorithm.

关键词： Evolution Strategy Good Nodes Set Constrained Optimization Problems

Regularity properties of a class of hybrid methods

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Communications in Nonlinear Science and Numerical Simulation 2000年第1期5卷 27-30页

作者： Daxue CHEN and Aiguo XIAO Department of Basic Sciences, Xiangtan college of Mechanical and Electrical engineering, Xiangtan411101,{2. Department of Mathematics, Xiangtan university, Xiangtan 411105,{2. e-mail: xiaoag@xtu. edu. cn, xag@lsec. cc. ac Department of Basic Sciences Xiangtan Coll. Mech. and Elec. Eng. Xiangtan 411101 China Department of Mathematics Xiangtan University Xiangtan 411105 China

The existence of spurious steady solutions and period-2.solutions in constant timestep is studied. The concepts of R[1]-regularity and R[2.-regularity of a class of hybrid methods for dynamical systems of ordinary differential equations are introduced and studied. Some conditions guaranteeing R[1]-regularity and R[2.-regularity of such methods applied to dynamical systems of ordinary differential equations with some important structures are given.

关键词： hybrid method dynamical system regularity spurious solution

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元宝草化学成分的研究

天然产物研究与开发 2002年第5期14卷 50-53页

作者：曾虹燕周朴华裴刚湘潭大学化工学院湖南农业大学理学院湖南中医学院湘潭411105 长沙41012. 长沙410007

目的　研究中药元宝草 (HypericumsampsoniiH .)的化学成分。方法　用乙醇或甲醇回流提取 ,聚酰胺柱色谱和重结晶分离 ,FT -IR ,MS ,UV ,1HNMR等方法确定结构。结果　分得了 4个化学成分 ,分别为芦丁 ,金丝桃苷 ,槲皮素和金丝桃素。结... 详细信息

目的　研究中药元宝草 (HypericumsampsoniiH .)的化学成分。方法　用乙醇或甲醇回流提取 ,聚酰胺柱色谱和重结晶分离 ,FT -IR ,MS ,UV ,1HNMR等方法确定结构。结果　分得了 4个化学成分 ,分别为芦丁 ,金丝桃苷 ,槲皮素和金丝桃素。结论　 4种化合物均为首次从元宝草中分得和检出。

关键词：元宝草金丝桃素芦丁金丝桃苷槲皮素

Asymmetric Synthesis ofα-CF3-α-Propargylamines by Acetylide Addition to(S)-N-tert-Butylsulfinyl Ketimines

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Asymmetric Synthesis ofα-CF3-α-Propargylamines by Acetylid...

氟化学与美好生活——中国化学会第十一届全国氟化学会议

作者： Heng-Qiao Xiao~1,Yan-Gen Huang~(1,*) 1 college of Chemistry,chemical {2. and Biotechnology,Donghua university,2.99 North Renmin Road,Shanghai 2.162.,china

Chiral propargylamine is one of the most important building blocks for the synthesis of many drugs and natural products,and meanwhile the trifluoromethyl-containing compounds have attracted much attention in pharmaceutical, agrochemical and materials sciences,so the synthetic method for trifluoromethylated chiral propargylamines are worth being ***,we wish to report an example of the asymmetric synthesis ofα-trifluoromethylatedα-propargylamines by the addition of lithium acetylides to the chiral CF-substituted(S)-N -tert-butylsulfinyl ketimines.

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A new approach to produce polystyrene monoliths by gelation and capillary shrinkage

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Science china Materials 2021年第9期64卷 2272-2279页

作者： Dewang Li Yaqian Deng Jingyi Xia Zhitan Wu Tongxin Shang Pei Li Junwei Han Ying Tao Quan-Hong Yang Nanoyang Group State Key Laboratory of chemical engineering School of chemical engineering and Technology Tianjin university Tianjin 300350 China Shenzhen Key Laboratory for Graphene-Based Materials Engineering Laboratory for Functionalized Carbon MaterialsGraduate School at ShenzhenTsinghua UniversityShenzhen 518055China Joint School of National university of Singapore and Tianjin university International Campus of Tianjin UniversityFuzhou 350207China

Polymeric monoliths are of great interest in a variety of applications.A new gelation approach to produce a mechanically stable polystyrene(PS)gel directly from its microemulsion is *** produce a PS gel,the as-prepared microemulsion is first demulsified by adding selected watermiscible organic *** small PS latex particles liberated from the surfactant are assembled into a piece of bulk material at an appropriate temperature with a high degree of entanglement of the polymer *** is found that the d2.T/ηvalue is an important parameter to evaluate the gelation ability of the organic solvents and helps determine the gelation ***,PS monoliths are obtained by capillary drying and their pore structures can be effectively tuned by changing the gelation time and the amount of solvent exchanged with *** allows the controlled preparation of bulk PS artefacts with densities in the range of 0.06 to 1.14 g cm^(-3).This simple method of PS monolith production avoids the use of shaping tools or chemical templates,needs less energy,and is a promising alternative approach to design either integrated porous or compact polymer materials.

关键词： polystyrene monolith demulsification gelation capillary shrinkage

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Signal Blind Recover in Communication Systems using Support Vector Machines

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Signal Blind Recover in Communication Systems using Support ...

2.08年中国高校通信类院系学术研讨会

作者： Yin Li-he~1 Ruan Xiu-kai~2.1 college of Electronic Science and engineering,Nanjing {2. of Posts & Telecommunications,Nanjing,2.0003 2.college of Telecommunications & Information engineering,Nanjing {2. of Posts & Telecommunications,Nanjing,2.0003

＜正＞This paper focuses on the applications of the support vector machine in solving the problem of blind recover in digital communication *** introduce the technique of support vector machine briefly,the development of blind equalization and analyze the problems which need to be resolved of the blind *** the applicability of support vector machine in blind problem is highlighted and ***,merit and shortage of blind equalization using support vector machine which is already exist to be discussed and the direction of further research is indicated.

关键词： Blind Equalization Support Vector Machines Lagrange Convex Quadratic programming BPSK

紫坪铺1号泄洪排沙隧洞挑流基岩冲刷模型试验研究

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四川水力发电 2004年第4期23卷 90-93页

作者：张晓东梁川付强张先起中国水利水电科学研究院水力学所北京100038 四川大学水电学院四川成都610065

高土石坝中由导流洞改建而成的永久性泄洪洞,由于导流洞的高程低,泄洪落差大、流速高,水流对下游基岩的冲刷是需要充分重视的问题。模型试验是研究基岩冲刷的强有力的方法。将该方法应用于紫坪铺1号泄洪排沙隧洞挑流基岩冲刷中,取得了... 详细信息

高土石坝中由导流洞改建而成的永久性泄洪洞,由于导流洞的高程低,泄洪落差大、流速高,水流对下游基岩的冲刷是需要充分重视的问题。模型试验是研究基岩冲刷的强有力的方法。将该方法应用于紫坪铺1号泄洪排沙隧洞挑流基岩冲刷中,取得了较好的效果,并分析了运用中所遇到的一些问题。

关键词：模型试验泄洪隧洞基岩冲刷挑流消能紫坪铺水利枢纽工程

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Ion exchange resins as recyclable and heterogeneous solid acid catalysts for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene

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Ion exchange resins as recyclable and heterogeneous solid ac...

中国化学会第二十五届学术年会

作者： Litao An, Jian-ping Zou* Key Laboratory of Organic Synthesis of Jiangsu Province, college of Chemistry and chemical {2., Suzhou university, 1 Shizi Street, Suzhou, Jiangsu, 2.5006 china