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TRANSMISSION BEHAVIOR OF MUD-PRESSURE PULSE ALONG WELL BORE

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Journal of Hydrodynamics 2007年第2期19卷 236-240页

作者： liu Xiu-shan LI Bo yuE yu-quan Petroleum Drilling Research Institute Exploration and Production Research Institute of Sinopec Corp. Dezhou 253005 China Technical Department Tianjin Branch of CNOOC Ltd. Tianjin 300452 China Jinzhou Oil Production Plant Liaohe Oilfield Branch of PetroChina Linghai 121209 China

In oil and gas industry, mud-pulse telemetry has been widely used to obtain directional data, drilling parameters, formation evaluation data and safety data, etc. Generally, the drilling mud in most current models was considered to be a single-phase fluid through which the mud pulses travel, despite the fact that the drilling mud is composed of two or more phases. In this article, a multiphase flow formula was proposed to calculate the mud-pulse velocity as mud solids and free-gas content change, and a mathematical model was put forward to simulate the dynamic-transmission behavior of the mud-pressure pulse or waves. Compared to conventional methods, the present model provides more accurate mud-pulse attenuation, and the dynamic-transmission behavior of drilling-mud pulses along well bores can also be easily examined. The model is valuable in improving the existing mud-pulse systems and developing new drilling-mud pulse systems.

关键词： measurement-while-drilling (MWD),closed-loop drilling multiphase flow numerical simulation

A recursive least squares algorithm with ?1 regularization for sparse representation

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Science China(Information Sciences) 2023年第2期66卷 281-282页

作者： Di liu Simone BALDI quan liu Wenwu yu School of Cyber Science and Engineering Southeast University School of Computation Information and Technology Technical University of Munich School of Mathematics Center for Mobile Communication and Security Southeast University School of Artificial Intelligence Southeast University

Sparse representation aims to identify a few basic elements in a signal, so as to use a combination of such elements to reconstruct the original signal. The ?1-norm has been widely applied in sparse representation, either when processing batches of data offline, or online as in adaptive filtering [1–3]. Representative algorithms for online sparse representation include zero-attracting LMS(ZA-LMS) [4],?1-RLS [5], ?1-RRLS [6], zero-attracting RLS(ZA-RLS) [7],

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高顶板沿空留巷帮壁收敛防治

西部探矿工程 2009年第12期21卷 83-84页

作者：闫玉彪单忠刚刘玉泉周明杰黑龙江科技学院黑龙江哈尔滨150027 七台河职业学院黑龙江七台河154600 七七台河职业学院黑龙江七台河154600 七煤集团新立煤矿黑龙江七台河154600

阐述锚索支护技术应用于沿空留巷高顶区巷道锁帮,采用锚索+道木的维护方式,理论上设计锚索的锚固长度,为沿空留巷高顶区巷道帮壁维护找到新的维护方式,解决了沿空留巷高顶区巷道帮壁片帮的维护难题。

关键词：沿空留巷巷道高顶区锁帮

两起电网故障分析及220kV断路器断口击穿保护探讨

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广东电力 2009年第5期22卷 62-66,72页

作者：鲁德锋刘育权吴国沛王莉广州供电局广州510620

介绍了两起断路器断口击穿造成的电网故障,分析了故障的发展过程及继电保护动作过程,通过对故障的分析,提出了在220kV系统保护配置中增设220kV断路器断口击穿保护的新思路,介绍了断路器断口击穿保护功能,并提出了具体可行的实现方案。

关键词：断路器断口击穿保护电网故障保护动作断路器分位失灵保护

基于自适应续流比的混合式步进电机转矩脉动抑制方法

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陕西科技大学学报 2025年第1期43卷 142-151,202页

作者：王焜刘宝泉刘艺张浩铭刘俊陕西科技大学电气与控制工程学院陕西西安710021 西安西电高压开关有限责任公司陕西西安710018

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前... 详细信息

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前时刻所需的续流模式.在快速续流模式下,实时监测电流指令与实际电流的差值Δi ref,通过自适应系数k动态调节续流时间,直至电机相电流快速下降至给定电流i ref后切换至缓慢续流模式.对续流时长与快速续流占总续流时间的比例自适应调节以适应不同工况下步进电机的平稳运行,有效降低了转矩脉动.最后,搭建MATLAB/Simulink仿真平台并进行实验验证,结果表明,与传统混合续流控制相比,所提方法能够有效减小步进电机的转矩脉动.

关键词：混合式步进电机自适应续流比电流纹波转矩脉动

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独山县直播稻发展现状、存在的问题及对策

耕作与栽培 2016年第5期36卷 71-72页

作者：陆跃飞张业黔刘玉全独山县农业技术推广站贵州独山558200

为加快独山县水稻直播技术推广,对独山县直播稻发展现状进行了介绍,分析发展直播稻存在的问题,提出了对策。

关键词：独山水稻直播稻对策

The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil treatment system

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Frontiers of Environmental Science & Engineering 2017年第2期11卷 133-142页

作者： Qinqin liu Miao Li Fawang Zhang Hechun yu quan Zhang Xiang liu Chinese Academy of Geological Sciences Beijing 100037 China China University of Geosciences (Beijing) Beijing 100083 China School of Environment Tsinghua University Beijing 100084 China Beijing Guohuan Tsinghua Environment Engineering Design & Research Institute Co. Ltd. Beijing 100084 China

Sulfamethoxzole （SMX） and trimethoprim （TMP）, two combined-using sulfonamide antibiotics, have gained increasing attention in the surface water, groundwater and the drinking water because of the ecological risk. The removal of TMP and SMX by artificial composite soil treatment system （ACST） with different infiltration rates was systematically investigated using K＋, Na＋, Ca2＋, Mg2＋ hydrogeochemical indexes. Batch experiments showed that the sorption onto the low-cost and commercially available clay ceramsites was effective for the removal of SMX and TMP from water. The column with more silty clay at high infiltration rate （1.394 m·d^-1） had removal rates of 80% to 90% for TMP and 60% to 70% for SMX. High SMX and TMP removal rates had a higher effluent concentration of K＋, Ca2＋ and Mg2＋ and had a lower effluent Na＋ concentration. Removal was strongly related to sorption. The results showed that the removal of SMX and TMP was related to hydrogeochemical processes. In this study, ACST is determined to be applicable to the drinking water plants.

关键词： TnmethoprimSulfamethoxazoleArtificial composite soil treatmentHydrogeochemical processesIon exchange

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基于排列法的目标威胁评估模型

现代防御技术 2004年第1期32卷 20-23页

作者：刘玉全李为民王君空军工程大学导弹学院陕西三原713800

目标威胁评估是一个推理、决策的行为,结合现代防空作战的特点和指挥自动化系统的工作过程,分析了影响目标威胁评估的几个重要因素,应用多属性决策中的一种改进排列法建立了数学模型,验证了其可行性。

关键词：多属性决策防空作战指挥自动化威胁判断战术单位级

Development of a micro gas turbine combustor with T-type vaporizers

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航空动力学报 2007年第7期22卷 1118-1126页

作者： XU quan-hong liu Jun XU Jian LIN yu-zhen liu Gao-en National Key Laboratory on Aero-Engines School of Jet PropulsionBeijing 13niversity of Aeronautics and Astronautics Beijing 100083 China

The study includes the experimental investigation of the evaporation performance of T-type vaporizer,mainly studied the relationship of the inlet air temperature and vaporizer wall temperature with the evaporation ***,it studied the LBO(lean blow out) and combustion efficiency of the micro aero-engine combustor with T-type vaporizer on the normal pressure test *** inlet air condition is environmental pressure and *** gas analysis method is used to study the combustion efficiency,and the inlet air temperature is 300 K,400 K and 500 *** could be concluded that the evaporation performance is improved with the increasing of the inlet air temperature and vaporizer wall temperature;the average LBO is 0.003;the combustion efficiency rises with the inlet air temperature,and it remain constant when the fuel/air ratio changed in the range from 0.008 to *** vaporization ratio is the key factor to determine the combustion performance.

关键词：离心式喷气发动机燃烧室喷雾器索特平均直径燃气涡轮