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Baoziwan-Majiashan Area of Jiyuan Oilfield Analysis of Reservoir Characteristics and Main Control Factors in Long 4 5 Section
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作者 Zhengxi Cui Zhipeng Zhang Mingling Shen 《Open Journal of Yangtze Oil and Gas》 2024年第2期48-64,共17页
Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir ... Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10<sup>−</sup><sup>3</sup> µm<sup>2</sup>. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir. 展开更多
关键词 Ordos Basin Jiyuan area Reservoir Characteristics Reservoir control Factor Long 4 5 Section
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A robust composite wide area control of a DFIG wind energy system for damping inter-area oscillations 被引量:8
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作者 Ayyarao S.L.V.Tummala 《Protection and Control of Modern Power Systems》 2020年第1期280-289,共10页
This paper presents a novel composite wide area control of a DFIG wind energy system which combines the Robust Exact Differentiator(RED)and Discontinuous Integral(DI)control to damp out inter-area oscillations.RED gen... This paper presents a novel composite wide area control of a DFIG wind energy system which combines the Robust Exact Differentiator(RED)and Discontinuous Integral(DI)control to damp out inter-area oscillations.RED generates the real-time differentiation of a relative speed signal in a noisy environment while DI control,an extension to a twisting algorithm and PID control,develops a continuous control signal and hence reduces chattering.The proposed control is robust to disturbances and can enhance the overall stability of the system.The proposed composite sliding mode control is evaluated using a modified benchmark two-area power system model with wind energy integration.Simulation results under various operating scenarios show the efficacy of the proposed approach. 展开更多
关键词 DFIG Wide area control Wind energy system Sliding mode control
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Occurrence and Control of Tetranychus truncatus and T. urticae on Corns of Yanbian Area 被引量:1
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作者 郑大浩 李真 金大勇 《Agricultural Science & Technology》 CAS 2016年第2期394-397,共4页
The situation of occurrence and hazards by Tetranychus truncatus and T. urticae on corns in test garden of Agricultural College of Yanbian University were narrated in detail. The characteristics of distribution and da... The situation of occurrence and hazards by Tetranychus truncatus and T. urticae on corns in test garden of Agricultural College of Yanbian University were narrated in detail. The characteristics of distribution and damage by T. truncates and T. urticae, morphological characteristics, the rule of currencies and its relation- ship with environment were summarized, and the methods of comprehensive treat- ment were put out, which could effectively control the hazard degree of T. truncates and T. urticae on corns. 展开更多
关键词 Tetranychus truncates Tetranychus urticae Corns OCCURRENCE Preven- tion and control Yanbian area
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Cause of over Water Quality Standard and Control Measures of State-controlled Sections in Northern Water-deficient Area of Jiangsu 被引量:5
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作者 胡永定 韩宝平 +1 位作者 钱新 袁兴程 《Meteorological and Environmental Research》 CAS 2010年第2期91-94,99,共5页
Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan r... Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology. 展开更多
关键词 State-controlled sections Cause analysis control measures Water-deficient area China
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A new wide area damping controller design method considering signal transmission delay to damp interarea oscillations in power system 被引量:8
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作者 杨波 孙元章 《Journal of Central South University》 SCIE EI CAS 2014年第11期4193-4198,共6页
Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damp... Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damping performance of WADC designed by the conventional method may deteriorate or even has no effect when signal transmission delay is beyond delay margin, an index that denotes delay endurance degree of power system. Therefore, a new design method for WADC under the condition of expected damping factor and required signal transmission delay is presented in this work. An improved delay margin with less conservatism is derived by adopting a new Lyapunov-Krasovskii function and more compact bounding technique on the derivative of Lyapunov-Krasovskii functional. The improved delay margin, which constructs the correlation of damping factor and signal transmission delay, can be used to design WADC. WADC designed by the proposed method can ensure that power system satisfies expected damping factor when WADC input signal is delayed within delay margin. Satisfactory test results demonstrate the effectiveness of the proposed method. 展开更多
关键词 power system wide area damping controller interarea oscillation time delay
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Robust H_∞ Load Frequency Control of Multi-area Power System With Time Delay:A Sliding Mode Control Approach 被引量:6
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作者 Yonghui Sun Yingxuan Wang +2 位作者 Zhinong Wei Guoqiang Sun Xiaopeng Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第2期610-617,共8页
This paper is devoted to investigate the robust H∞sliding mode load frequency control(SMLFC) of multi-area power system with time delay. By taking into account stochastic disturbances induced by the integration of re... This paper is devoted to investigate the robust H∞sliding mode load frequency control(SMLFC) of multi-area power system with time delay. By taking into account stochastic disturbances induced by the integration of renewable energies,a new sliding surface function is constructed to guarantee the fast response and robust performance, then the sliding mode control law is designed to guarantee the reach ability of the sliding surface in a finite-time interval. The sufficient robust frequency stabilization result for multi-area power system with time delay is presented in terms of linear matrix inequalities(LMIs). Finally,a two-area power system is provided to illustrate the usefulness and effectiveness of the obtained results. 展开更多
关键词 Index Terms--Load frequency control (LFC) multi-area powersystem robust control sliding mode control (SMC) time delay.
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Production Characteristics and the Control Factors of Surface Wells for Relieved Methane Drainage in the Huainan Mining Area 被引量:6
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作者 XU Hongjie SANG Shuxun +1 位作者 FANG Liangcai HUANG Huazhou 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第4期932-941,共10页
Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recogniz... Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer. 展开更多
关键词 relieved methane surface drainage well Huainan mining area production characteristic control factor
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Resilient Fixed-Order Distributed Dynamic Output Feedback Load Frequency Control Design for Interconnected Multi-Area Power Systems 被引量:4
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作者 Ali Azarbahram Amir Amini Mahdi Sojoodi 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第5期1139-1151,共13页
The paper proposes a novel H∞ load frequency control(LFC) design method for multi-area power systems based on an integral-based non-fragile distributed fixed-order dynamic output feedback(DOF) tracking-regulator cont... The paper proposes a novel H∞ load frequency control(LFC) design method for multi-area power systems based on an integral-based non-fragile distributed fixed-order dynamic output feedback(DOF) tracking-regulator control scheme. To this end, we consider a nonlinear interconnected model for multiarea power systems which also include uncertainties and timevarying communication delays. The design procedure is formulated using semi-definite programming and linear matrix inequality(LMI) method. The solution of the proposed LMIs returns necessary parameters for the tracking controllers such that the impact of model uncertainty and load disturbances are minimized. The proposed controllers are capable of receiving all or part of subsystems information, whereas the outputs of each controller are local. These controllers are designed such that the resilient stability of the overall closed-loop system is guaranteed. Simulation results are provided to verify the effectiveness of the proposed scheme. Simulation results quantify that the distributed(and decentralized) controlled system behaves well in presence of large parameter perturbations and random disturbances on the power system. 展开更多
关键词 Dynamic OUTPUT FEEDBACK control interconnected multi-area POWER systems load frequency control linear MATRIX INEQUALITIES POWER system control
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Reliability Analysis of Controller Area Network Based Systems—A Review 被引量:2
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作者 Gerardine Immaculate Mary Zachariah C. Alex Lawrence Jenkins 《International Journal of Communications, Network and System Sciences》 2013年第4期155-166,共12页
This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a... This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a mature technique which for nontrivial systems can be used to determine whether a set of tasks executing on a single CPU or in a distributed system will meet their deadlines or not [1-3]. The main focus of the real-time research community is on hard real-time systems, and the essence of analyzing such systems is to investigate if deadlines are met in a worst case scenario. Whether this worst case actually will occur during execution, or if it is likely to occur, is not normally considered. Reliability modeling, on the other hand, involves study of fault models, characterization of distribution functions of faults and development of methods and tools for composing these distributions and models in estimating an overall reliability figure for the system [4]. This paper presents the research work done on reliability analysis developed with a focus on Controller-Area-Network-based automotive systems. 展开更多
关键词 Reliability Analysis of controlLER area Network BASED SYSTEMS FAULT-TOLERANT CAN BASED SYSTEMS
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Risk prevention and control strategies for the severely affected areas of snow disaster in the Three Rivers Source Region(TRSR), China 被引量:1
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作者 ShiJin Wang ShengYun Chen YanQiang Wei 《Research in Cold and Arid Regions》 CSCD 2019年第3期248-252,共5页
Historically,frequent and heavy snow disaster(SD)has caused serious livestock death and casualties,resulting in a devastating impact on animal husbandry development in the Three Rivers Source Region(TRSR).From winter ... Historically,frequent and heavy snow disaster(SD)has caused serious livestock death and casualties,resulting in a devastating impact on animal husbandry development in the Three Rivers Source Region(TRSR).From winter in 2018 to spring in 2019,the largest SD occurred in this area over the past 10 years,especially in core zones of the Lancang River Source Region.Field research results show that the main causes of the major SD include weak infrastructure(i.e.,roads,communications,warm sheds,and insufficient forage reserve),low rate of domestic animals for sale before the SD,and low loss settlement rate.SD occurrence could furtherly reduce the ability of disaster prevention,mitigation and relief of disaster loss.In the future,heavily affected SD areas should improve the forecasting ability of snowfall incidents,strengthen infrastructure construction,implement grass and livestock balance strategies,optimize livestock structure,improve loss settlement rate,and develop a modern compound model of animal husbandry development model that combines breeding,slaughtering and deep processing of animal product. 展开更多
关键词 THREE RIVERS Source Region SNOW DISASTER severely AFFECTED area risk prevention control strategy
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Architecture Design for Integrated Wide Area Protection and Control Systems 被引量:2
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作者 Z. Q. Bo Q. P. Wang +3 位作者 Lin Wang Fengqun Zhou Shengming Ge B. M. Zhang 《Journal of Power and Energy Engineering》 2015年第4期412-416,共5页
This paper firstly reviews the recent development in power system protection and control, with special attention paid to the wide-area and integrated protection, in order to look into future development of integration... This paper firstly reviews the recent development in power system protection and control, with special attention paid to the wide-area and integrated protection, in order to look into future development of integration of protection and control for smart grids. This paper mainly reports on the development of integrated wide area protection and control for power systems. The concept of integrated wide area protection and control is introduced, in which a hierarchical protection and control system provides the protection and control of wide area or regional power substations/ plants and their associated power network. The system is mainly divided into three levels, the local, the substation/plant and the wide area/regional protection and control. The integrated functions at each level are described in details with an aim to develop an optimal coordination mechanism between the levels. One of the core elements in the system is the synchronised wide area communication network between the substations and the protection and control system, in which latest communication technology is employed. Another important player in the system is the wide area synchronized protection and control information platform, which not only enables the fusion three line of defence for power system protection and control, but also provides a perfect tool for the application of cloud computing to substations and power networks. 展开更多
关键词 INTEGRATED PROTECTION WIDE area PROTECTION PROTECTION and control CLOUD COMPUTING
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Study on Division Method of Quality Monitoring Control Area Based on Comprehensive Cultivated Land Attribute
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作者 Ziwei WANG Lingchao WANG +3 位作者 Yanhua SONG Chenguang YUAN Lei WANG Xihui YANG 《Meteorological and Environmental Research》 CAS 2022年第6期84-87,共4页
The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study ... The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study of natural quality,utilization level,income level,and utilization characteristics,etc.Compared with the traditional administrative unit division or cultivated land quality division method,the regional homogeneity of this study is stronger,and there are quality differences between regions.It provides precondition and precision guarantee for the monitoring of cultivated land quality. 展开更多
关键词 Cultivated land quality monitoring control area DIVISION Cultivated land attribute
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MINERALOGICAL CHARACTERISTICS AND CONTROL FACTORS OF SURFACE SEDIMENTS IN THE SEA AREA NORTHWEST OF THE ANTARCTIC PENINSULA
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作者 Ma Kejian Li Zhizhen Gao Shuitu 《Chinese Journal of Polar Science》 1991年第2期75-82,87-88,共10页
Analysis and study of clastic and clay minerals of surface sediments and their chemical composition in the sea area northwest of the Antarctic Peninsula enable the authors to divide this area basically into four miner... Analysis and study of clastic and clay minerals of surface sediments and their chemical composition in the sea area northwest of the Antarctic Peninsula enable the authors to divide this area basically into four mineralogical provinces : (1) the mineral ogical province of coast and island shelf of the Southern Shetland Islands, (2) the mineral ogical province of the eastern Bransfield Strait, (3) the mineral ogical province of the western Bransfield Strait, and (4) the mineral ogical province of the western Antarctic Peninsula. Finally, the relationships between the mineral distribution and geologic ,structure, material sources, glaciers, currents, and environments are briefly described. 展开更多
关键词 Antarctic Peninsula Sea area control factors mineralogical characteristics.
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Impact of Village-based Health Education of Tobacco Control on the Current Smoking Rate in Chinese Rural Areas
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作者 王坚苗 熊维宁 +4 位作者 谢俊刚 刘先胜 赵建平 张珍祥 徐永健 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2016年第1期150-152,共3页
The number of smokers in Chinese rural areas is more than 200 million, which is twice that in cities. It is very significant to carry out tobacco control interventions in rural areas. We performed this community inter... The number of smokers in Chinese rural areas is more than 200 million, which is twice that in cities. It is very significant to carry out tobacco control interventions in rural areas. We performed this community intervention study to evaluate the efficacy of village-based health education of tobacco control on the male current smoking rate in rural areas. The population of this study was the males above 15 years old from 6 villages in rural areas. The villages were randomly assigned to intervention group or control group(3 villages in each group). Self-designed smoking questionnaire was applied. The intervention group received the village-based health education of tobacco control for one year. The primary outcome measurement was the male current smoking rate. In the baseline investigation, completed surveys were returned by 814 male residents from the control group and 831 male residents from the intervention group. The male current smoking rate in the control group and the intervention group was 61.2% and 58.5%, respectively, before intervention. There was no significant difference between these two groups(P〉0.05). After one-year intervention, the current smoking rate in the intervention group(51.2%) was significantly lower than that in the control group(62.8%)(P〈0.001). Our study suggested that the village-based health education of tobacco control was effective in lowering the male current smoking rate in rural areas, which could be a suitable and feasible way for tobacco control in the Chinese rural areas. 展开更多
关键词 health education rural areas smoking rate tobacco control
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Advancement in Wide Area Monitoring Protection and Control Using PMU’s Model in MATLAB/SIMULINK
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作者 Waheed Ur Rahman Muhammad Ali +7 位作者 Amjad Ullah Hafeez Ur Rahman Majid Iqbal Haseeb Ahmad Adnan Zeb Zeeshan Ali M. Ahsan Shahzad Beenish Taj 《Smart Grid and Renewable Energy》 2012年第4期294-307,共14页
A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power system... A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power systems worldwide and has led to operation of power systems closer to their stability limits and to power exchange in new patterns. These issues, as well as the on-going worldwide trend towards deregulation of the entire industry on the one hand and the increased need for accurate and better network monitoring on the other hand, force power utilities exposed to this pressure to demand new solutions for wide area monitoring, protection and control. Wide-area monitoring, protection, and control require communicating the specific-node information to a remote station but all information should be time synchronized so that to neutralize the time difference between information. It gives a complete simultaneous snap shot of the power system. The conventional system is not able to satisfy the time-synchronized requirement of power system. Phasor Measurement Unit (PMU) is enabler of time-synchronized measurement, it communicate the synchronized local information to remote station. 展开更多
关键词 WIDE area MONITORING Protection and control (WAMPAC) Phasor Measurement uNit (PMU) WIDE area MONITORING (WAM) Global Positioning System (GPS) WIDE area controlLER (WAC) Local area controlLER (LAC) Phase Angle MONITORING (PAM) Automatic Generation control (AGC) Circuit Breaker (CB) Current TRANSFORMERS (CTs) Potential TRANSFORMERS (PTs)
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Physical property characteristics of Yanchang Formation reservoir in the southwest of Ordos Basin and their controlling fac-tors: taking Chang 3 and Chang 4 + 5 reservoirs in Longdong area as an example 被引量:1
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作者 吴旭光 《西安石油大学学报(自然科学版)》 CAS 北大核心 2014年第6期I0001-I0007,47,共7页
分析鄂尔多斯盆地西南部陇东地区延长组储层物性特征及其控制因素,发现沉积和成岩控制储层物性。沉积微相带不同,储层物性就不同;成岩作用中压实-压溶作用、胶结作用对储层物性具有破坏作用,溶蚀作用是储层物性改善的关键因素。沉... 分析鄂尔多斯盆地西南部陇东地区延长组储层物性特征及其控制因素,发现沉积和成岩控制储层物性。沉积微相带不同,储层物性就不同;成岩作用中压实-压溶作用、胶结作用对储层物性具有破坏作用,溶蚀作用是储层物性改善的关键因素。沉积微相带是控制油气藏储层展布的内在因素,成岩作用是储层形成过程中控制物性演化的外部因素。 展开更多
关键词 摘要 编辑部 编辑工作 读者
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Controlling Factors Affecting Pressure Differential Development of the Upper Paleozoic Gas Reservoir in the Sulige and Yulin Area of the Ordos Basin
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作者 Hao Xu~1,Junfeng Zhang~2,Chengzao Jia~3,Dazhen Tang~1,Ming Li~3,Wenzhong Zhang~1 1.Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,Ministry of Education,China University of Geosciences(Beijing),Beijing 100083,China. 2.PetroChina Exploration and Production Company,Beijing 100724,China 3.Research Institute of Petroleum Exploration & Development,Beijing 100083,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期126-127,共2页
The origin and distribution of Upper Paleozoic reservoirs pressure in mid-northem Ordos Basin has attracted widespread attention in recent years.The reservoir pressure of Sulige area shows characteristics of basically... The origin and distribution of Upper Paleozoic reservoirs pressure in mid-northem Ordos Basin has attracted widespread attention in recent years.The reservoir pressure of Sulige area shows characteristics of basically subnormal pressure,and the reservoir pressure of Yulin area shows characteristics of basically normal hydrostatic pressure.In the sense of structural location, 展开更多
关键词 ORDOS BASIN SULIGE area Yulin area formation PRESSURE controlling FACTORS
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M/S Controller Area Network(CAN) System Using Shared-Clock Scheduler
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作者 LIU Jianxin1,TAN Ping2,LIU Yu1 (1.School of Mechanical Engineering & Automation,Xihua University,Chengdu 610039,China 2.School of Mathematical & Computer Science,Xihua University,ChengDu 610039,China) 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S1期284-288,共5页
The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a ses... The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a session layer,for message scheduling,to the existing CAN standard,which is a two layer standard comprising of a physical layer and a data link layer. TTCAN facilitates network communication in a time-triggered fashion,by introducing a Time Division Multiple Access style communication scheme. This allows deterministic network behavior,where maximum message latency times can be quantified and guaranteed. In order to solve the problem of determinate time latency and synchronization among several districted units in one auto panel CAN systems,this paper proposed a prototype design implementation for a shared-clock scheduler based on PIC18F458 MCU. This leads to improved CAN system performance and avoid the latency jitters and guarantee a deterministic communication pattern on the bus. The real runtime performance is satisfied. 展开更多
关键词 TIME-TRIGGERED controller area network auto PANEL shared-clock SCHEDULER embedded SYSTEM
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Unified Smith Predictor Based H_∞ Wide-Area Damping Controller to Improve the Control Resiliency to Communication Failure 被引量:2
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作者 Mithu Sarkar Bidyadhar Subudhi Sandip Ghosh 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第2期584-596,共13页
Inter-area low frequency oscillation in power system is one of the major problems for bulk power transmission through weak tie lines.Use of wide-area signal is more effective than the local area signal in damping out ... Inter-area low frequency oscillation in power system is one of the major problems for bulk power transmission through weak tie lines.Use of wide-area signal is more effective than the local area signal in damping out the inter-area oscillations.Wide area measurement system(WAMS)is convenient to transmit the wide area signal through the communication channel to the remote location.Communication failure is one of the disastrous phenomena in a communication channel.In this paper,a dual input single output(DISO)Hm controller is designed to build the control resiliency by employing two highest observability ranking wide area signals with respect to the critical damping inter-area mode.The proposed controller can provide sufficient damping to the system and also the system remains stabilized if one of the wide-area signals is lost.The time delay is an unwanted phenomenon that degrades the performance of the controllers.The unified Smith predictor approach is used to design a Hm controller to handle the time delay.Kundur's two-area and IEEE-39 bus test systems are considered to verify the effectiveness of the proposed controller.From the simulation results,it is verified that,the proposed controller provides excellent damping performance at normal communication and improves the controller resiliency to counteract the communication failure. 展开更多
关键词 Communication failure dual input single output(DISO)controller H_∞control inter-area oscillation unified Smith predictor
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Geological Factors Controlling the Accumulation and High Yield of Marine-Facies Shale Gas: Case Study of the Wufeng-Longmaxi Formation in the Dingshan Area of Southeast Sichuan, China 被引量:8
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作者 FAN Cunhui ZHONG Cheng +2 位作者 ZHANG Yu QIN Qirong HE Shun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第3期536-560,共25页
The main geological factors controlling the accumulation and yield of marine-facies shale gas reservoirs are the focus of the current shale gas exploration and development research.In this study,the Wufeng-Longmaxi Fo... The main geological factors controlling the accumulation and yield of marine-facies shale gas reservoirs are the focus of the current shale gas exploration and development research.In this study,the Wufeng-Longmaxi Formation in the Dingshan area of southeast Sichuan was investigated.Shale cores underwent laboratory testing,which included the evaluation of total organic carbon(TOC),vitrinite reflectance(Ro),whole-rock X-ray diffraction(XRD),pore permeability,and imaging through field emission scanning electron microscopy(FE-SEM).Based on the results of natural gamma ray spectrum logging,conventional logging,imaging logging,and seismic coherence properties,the exploration and development potential of shale gas in the Dingshan area have been discussed comprehensively.The results showed that(1)layer No.4(WF2-LM4)of the Wufeng-Longmaxi Formation has a Th/U ratio<2 and a Th/K ratio of 3.5–12.Graptolites and pyrite are relatively abundant in the shale core,indicating sub-high-energy and low-energy marine-facies anoxic reducing environments.(2)The organic matter is mainly I-type kerogen with a small amount of II1-type kerogen.There is a good correlation among TOC,Ro,gas content,and brittle minerals;the fracturing property(brittleness)is 57.3%.Organic and inorganic pores are moderately developed.A higher pressure coefficient is correlated with the increase in porosity and the decrease in permeability.(3)The DY1 well of the shale gas reservoir was affected by natural defects and important latestage double destructive effects,and it is poorly preserved.The DY2 well is located far from the Qiyueshan Fault.Large faults are absent,and upward fractures in the Longmaxi Formation are poorly developed.The well is affected by low tectonic deformation intensity,and it is well preserved.(4)The Dingshan area is located at the junction of the two sedimentary centers of Jiaoshiba and Changning.The thickness of the high-quality shale interval(WF2-LM4)is relatively small,which may be an important reason for the unstable production of shale gas thus far.Based on the systematic analysis of the geological factors controlling high-yield shale gas enrichment in the Dingshan area,and the comparative analysis with the surrounding typical exploration areas,the geological understanding of marine shale gas enrichment in southern China has been improved.Therefore,this study can provide a useful reference for shale gas exploration and further development. 展开更多
关键词 MAIN controlling factors ENRICHMENT CONSERVATION SHALE gas Dingshan area
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