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Convergence Rates to Asymptotic Profile for Solutions of Quasilinear Hyperbolic Equations with Nonlinear Damping

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Acta Mathematicae Applicatae Sinica 2016年第1期32卷 55-66页

作者： shi-feng geng Zhen WANG School of Mathematics and Computational Science Xiangtan University Wuhan Institute of Physics and Mathematics The Chinese Academy of Sciences

The quasilinear hyperbolic equation with nonlinear damping is considered in this paper,a new asymptotic profile for the solution to the equation is obtained by suitably choosing the initial data of the corresponding parabolic equation,the convergence rates of the new profile are better than that obtained by Nishihara（1997,*** Equations 137,384-395） and H.-***（2000,*** Equations 167,467-494）.

关键词： asymptotic behavior convergence rates quasilinear hyperbolic equation nonlinear damping

Network boundary recognition via relative azimuth angle

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The Journal of China Universities of Posts and Telecommunications 2010年第4期17卷 31-41页

作者： JIA Rui-wu shi geng-chen National Lab of Mechatronic Engineering and Control Beijing Institute of Technology Beijing 100081 China

To recognize the boundary of wireless networks to meet some specific needs, relative azimuth angles of nodes distributed in the 1-hop neighborhood of each node in one network were used to recognize the boundary of the network. A novel recognition algorithm based on local generalized convex hull was proposed for one node to decide if it self is a boundary node. The flexibility, efficiency and consistency of the algorithm are shown in its performance by extensive simulations.

关键词： wireless sensor network boundary point generalized convex hull relative azimuth angle θ-hull

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利用热网蓄能辅助供热机组调频的控制研究

计算机仿真 2024年第5期41卷 102-106,115页

作者：殳建军史耕金江苏方天电力技术有限公司江苏南京211102 清华大学能源与动力工程系北京100084 北京新叶科技有限公司北京100085

随着如风电、太阳能等可再生能源的并网,使得火电机组需要进行深度调峰且快速响应调度指令。然而,传统的负荷调节控制方法难以使得机组应对调度指令的频繁变化。火电机组热网包含着大量的管道与热力设备,它们均具有很强的蓄热能力,合理... 详细信息

随着如风电、太阳能等可再生能源的并网,使得火电机组需要进行深度调峰且快速响应调度指令。然而,传统的负荷调节控制方法难以使得机组应对调度指令的频繁变化。火电机组热网包含着大量的管道与热力设备,它们均具有很强的蓄热能力,合理利用其蓄热可在短时间内提升机组负荷响应速度。针对上述问题,对利用热网蓄能辅助供热机组负荷调节进行了研究,并设计了基于调度指令与负荷响应偏差的协调控制系统。仿真结果表明,所设计的协调控制系统能够提高机组负荷响应调度指令的能力,且保证供热压力的稳定。

关键词：火电机组蓄能热网协调控制系统负荷调节

A Modeling and Probabilistic Reasoning Method of Dynamic Uncertain Causality Graph for Industrial Fault Diagnosis

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International Journal of Automation and computing 2014年第3期11卷 288-298页

作者： Chun-Ling Dong Qin Zhang shi-Chao geng Department of Geographical Information System Shandong Normal University School of Computer Science and Engineering Beihang University Institute of Nuclear and New Energy Technology Tsinghua University

Online automatic fault diagnosis in industrial systems is essential for guaranteeing safe, reliable and efficient ***, difficulties associated with computational overload, ubiquitous uncertainties and insufficient fault samples hamper the engineering application of intelligent fault diagnosis technology. Geared towards the settlement of these problems, this paper introduces the method of dynamic uncertain causality graph, which is a new attempt to model complex behaviors of real-world systems under uncertainties. The visual representation to causality pathways and self-relied "chaining" inference mechanisms are analyzed. In particular, some solutions are investigated for the diagnostic reasoning algorithm to aim at reducing its computational complexity and improving the robustness to potential losses and imprecisions in observations. To evaluate the effectiveness and performance of this method, experiments are conducted using both synthetic calculation cases and generator faults of a nuclear power plant. The results manifest the high diagnostic accuracy and efficiency, suggesting its practical significance in large-scale industrial applications.

关键词： Fault diagnosis causality model probabilistic graphical model uncertain knowledge representation weighted logic inference.

A Class of Stochastic Diferential Equations with the Time Average

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Acta Mathematica Sinica,English Series 2014年第3期30卷 525-538页

作者： Rong Cheng YIN Fu Ke WU shi geng HU School of Mathematical Sciences Nanjing Normal University School of Mathematics and Statistics Huazhong University of Science and Technology

Stochastic diferential equations with the time average have received increasing attentions in recent years since they can ofer better explanations for some fnancial *** the time average is involved in this class of stochastic diferential equations,in this paper,the linear growth condition and the Lipschitz condition are diferent from the classical *** the special linear growth condition and the special Lipschitz condition,this paper establishes the existence and uniqueness of the *** using the Lyapunov function,this paper also establishes the existence and uniqueness under the local Lipschitz condition and gives the p-th moment ***,a scalar example is given to illustrate the applications of our results.

关键词： Stochastic differential equation time average existence uniqueness moment estimate

PetroKG: Construction and Application of Knowledge Graph in Upstream Area of PetroChina

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Journal of Computer Science & Technology 2020年第2期35卷 368-378页

作者： Xiang-Guang Zhou Ren-Bin Gong Fu-geng shi Zhe-Feng Wang PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Huawei Technologies Hangzhou 310007China

There is a large amount of heterogeneous data distributed in various sources in the upstream of PetroChina. These data can be valuable assets if we can fully use them. Meanwhile, the knowledge graph, as a new emerging technique, provides a way to integrate multi-source heterogeneous data. In this paper, we present one application of the knowledge graph in the upstream of PetroChina. Specifically, we first construct a knowledge graph from both structured and unstructured data with multiple NLP (natural language progressing) methods. Then, we introduce two typical knowledge graph powered applications and show the benefit that the knowledge graph brings to these applications:compared with the traditional machine learning approach, the well log interpretation method powered by knowledge graph shows more than 7.69% improvement of accuracy.

关键词： knowledge graph natural language processing oil and gas industry

长期有机种植模式下日光温室蔬菜栽培土壤真菌多样性研究

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农业生物技术学报 2024年第3期32卷 641-654页

作者：曾广娟王晗赵美微彭红丽冯阳耿世刚河北环境工程学院河北省农业生态安全重点实验室河北省农林科学院昌黎果树研究所企美实业集团有限公司

有机种植能够通过保护土壤有机质来提高土壤肥力和生物多样性；温室栽培可以人为控制植物生长环境，保护作物免受病虫害、极端天气条件和农药漂移等室外干扰。本研究以2种不同土地利用方式(日光温室和露地)(0～15) cm表层土壤和(15～30)... 详细信息

有机种植能够通过保护土壤有机质来提高土壤肥力和生物多样性；温室栽培可以人为控制植物生长环境，保护作物免受病虫害、极端天气条件和农药漂移等室外干扰。本研究以2种不同土地利用方式(日光温室和露地)(0～15) cm表层土壤和(15～30) cm深层土壤为研究对象，采用Illumina高通量测序技术分析土壤真菌群落结构的差异，基于距离的冗余分析(distance-based redundancy analysis, dbRDA)明确影响真菌群落结构的土壤环境因子，结合FunGuild分析土壤真菌功能对日光温室栽培的响应。结果表明，温室有机栽培显著降低了表层土壤真菌群落的丰富度和多样性(P<0.05)。不同土地利用方式的优势真菌均为子囊菌门(Ascomycota)、球囊菌门(Glomeromycota)和担子菌门(Basidiomycota)，不同土地利用方式没有改变土壤优势真菌的种类，但显著影响了其相对丰度。日光温室栽培增加了Chaetomium、Mortierella、Orbilia、Acaulospora等有益真菌的数量和丰度，抑制了表层土壤中植物病原菌Fusarium的生长。组间群落差异分析(LEfSe)表明，温室及露地土壤分别检测到22和21个显著差异物种。温室土壤中的被孢霉门(Mortierellomycota)、罗兹菌门(Rozellomycota)及Chaetomium、Mortierella、Humicola 3个真菌菌属为显著差异菌群；露地土壤中Fusarium、Stachybotry、Cephaliophora 3个菌属起主导作用。dbRDA分析表明，全钾(total potassium, TK)、土壤有机质(soil organic matter, SOM)、pH、全氮(total nitrogen, TN)、全磷(total phosphorus, TP)是显著影响温室土壤真菌群落的环境因子。FunGuild功能预测分析显示，温室土壤中最优势的功能类群为土壤腐生菌，露地土壤中最优势的功能类群为病理-腐生菌。综上，有机种植模式下温室蔬菜栽培能显著影响真菌群落结构和功能，提高土壤有益真菌相对丰度，降低病原真菌丰度，真菌生态功能的改变与不同土地利用方式带来的环境变化相适应。本研究揭示了有机种植模式下日光温室蔬菜栽培对土壤真菌群落结构及其功能的影响，可为温室条件下土壤真菌的群落组成和长期有机耕作提供理论依据。

关键词：有机种植日光温室高通量测序真菌群落多样性

Stability of Stochastic Differential Delay Equations with Markovian Switching

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Journal of Mathematical Research and Exposition 2008年第3期28卷 511-520页

作者： DAI Wei Xing HU shi geng Department of Mathematics Huazhong University of Science and Technology Hubei 430074 China

The main aim of this paper is to investigate the pth moment exponential stability of stochastic differential delay equations with Markovian switching.A specific Lyapunov function is introduced to obtain the required s... 详细信息

关键词： Lyapunov function delay equation generalized Ito's formula Brownian motion Markov chain.

Characteristics of China’s oil and gas pool formation in latest geological history

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Science China Earth Sciences 2006年第9期49卷 947-959页

作者： JIA Chengzao HE Dengfa shi Xin YANG geng ZHANG Chaojun PetroChina Exploration and Development Research Institute Beijing 100083 China PetroChina Exploration and Development Research Institute Beijing 100083 China PetroChina Exploration and Development Research Institute Beijing 100083 China PetroChina Exploration and Development Research Institute Beijing 100083 China PetroChina Exploration and Development Research Institute Beijing 100083 China

The structural activities took place extensively in the Asia continent during the Cenozoic era owing to the strong continent-to-continent collision and continuous compression between the India Plate and the Eurasia Plate. Huang Jiqing called such structural activities Himalayan movement. China’s sedimentary basins developed and took shape mainly during the Himalayan movement period. It is also the main period for formation and development of the oil and gas reservoirs. Of 366 large and medium-sized oil and gas fields currently found in China, 212 reservoirs were formed in the Neo- gene-Quaternary period. The proportion is as high as 68.2%. The oil and gas migration and accumu- lation in the latest geological period, which were controlled by the times, properties, styles and strength of the Himalayan movement, took place mainly in eight regions, such as the low uplift area of Bohai Sea, the onshore faulted sag area of Bohai Bay, anticlinorium zone in Daqing, the foreland fold-and-thrust belt in West China, the tilted structural zone in West China, the cratonic palaeohigh in the Tarim Basin, the zone of fault and fold belt in the East Sichuan Basin, and the biological gas zone in the East Qaidam Basin. The oil and gas pool formations in those regions have their own charac- teristics. With the great potential and broad prospect, those regions are the main exploration areas in China in the future.

关键词： Himalayan movement, oil and gas pool formation, Neogene, Quaternary, foreland basin, cratonic basin, extensional basin, China.