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新构造运动期断裂活动对油气的控制作用——以渤中地区为例 被引量:22
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作者 庄新兵 邹华耀 滕长宇 《中国矿业大学学报》 EI CAS CSCD 北大核心 2012年第3期452-459,共8页
新构造运动调整和控制了渤中地区油气的成藏和最终分布.本文将定性评价与半定量刻画相结合,系统分析了渤中地区的断裂系统特征和62条Ⅰ,Ⅱ级断裂活动速率(FAR)的差异,探讨了晚期断裂活动对成藏条件和油气成藏过程的控制作用.结果表明:... 新构造运动调整和控制了渤中地区油气的成藏和最终分布.本文将定性评价与半定量刻画相结合,系统分析了渤中地区的断裂系统特征和62条Ⅰ,Ⅱ级断裂活动速率(FAR)的差异,探讨了晚期断裂活动对成藏条件和油气成藏过程的控制作用.结果表明:强烈活动(FAR>25m/Ma)断裂对油气主要起输导作用,微弱活动(FAR<10m/Ma)断裂主要起封闭作用,中等活动(10m/Ma<FAR<25m/Ma)断裂则对油气起封闭与输导共同作用;断层沿走向对油气的输导与封闭呈现"分段式"特点,"分段式"断裂活动控制了多层系油气富集;远源凸起的缓坡带油气优势运移路径上的圈闭,凸起末端烃源岩发育、断裂活动中-弱的古近系的圈闭,以及断裂活动中-强的断裂与"活跃"烃源岩最佳组合区域的圈闭是有利的油气勘探领域. 展开更多
关键词 断层活动速率 分段式 油气成藏 新构造运动 渤中地区
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内置式永磁电机齿槽转矩的分析研究 被引量:14
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作者 谢芳 黄守道 刘婷 《微特电机》 北大核心 2009年第11期11-14,共4页
内置式永磁电机因其高转矩及能量密度,在许多高性能装置中得到广泛应用。但永磁电机结构的特殊性,转子永磁体和定子齿槽之间相互作用产生的齿槽转矩会引起振动和噪声,同时齿槽转矩会降低速度和位置控制系统的低速时的性能。研究了一种... 内置式永磁电机因其高转矩及能量密度,在许多高性能装置中得到广泛应用。但永磁电机结构的特殊性,转子永磁体和定子齿槽之间相互作用产生的齿槽转矩会引起振动和噪声,同时齿槽转矩会降低速度和位置控制系统的低速时的性能。研究了一种内置式结构永磁电机的齿槽转矩,其转子磁极永磁体分段。根据分析可知,在相同的等级及尺寸条件下,永磁体分段的内置式永磁电机(SIPMM)比传统非分段内置式永磁电机(IPMM)的齿槽转矩低得多,然后利用有限元软件Maxwell 2D计算分析比较了SIPMM与IPMM的齿槽转矩。此外,还分析了两种不同转子结构的内置式永磁电机的齿槽转矩情况。 展开更多
关键词 内置式永磁电机 有限元分析 齿槽转矩 分段
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Straw layer burial to alleviate salt stress in silty loam soils: Impacts of straw forms 被引量:9
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作者 ZHANG Hong-yuan LU Chuang +3 位作者 PANG Huan-cheng LIU Na ZHANG Xiao-li LI Yu-yi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第1期265-276,共12页
Salt stress can be alleviated by straw layer burial in the soil, but little is known of the appropriate form of the straw layer for optimal regulation of soil water and salinity because of the uncontrollability of fie... Salt stress can be alleviated by straw layer burial in the soil, but little is known of the appropriate form of the straw layer for optimal regulation of soil water and salinity because of the uncontrollability of field tests. Here, the following four straw forms with compaction thickness of 5 cm buried 40–45 deep were studied: no straw layer(CK), segmented straw(SL, 5 cm in length), straw pellet(SK), and straw powder(SF). The three straw forms(SL, SK and SF) significantly delayed the infiltration of irrigation water down the column profile by 71.20–134.3 h relative to CK and the migration velocity of the wetting front under SF was the slowest. It took longer for the wetting front to transcend SK than SL but shorter for it to reach the bottom of soil column after water crossed the straw layer. Compared with CK, the average volumetric water content in the 0–40 cm soil layer increased by 6.45% under SL, 1.77% under SK and 5.39% under SF. The desalination rates at the 0–40 and 0–100 cm soil layers increased by 5.85 and 3.76% under SL, 6.64 and 1.47% under SK and 5.97 and 4.82% under SF. However, there was no significant difference among straw forms in the 0–40 cm soil layer. Furthermore, the salt leaching efficiency(SLE, g mm^–1 h^–1) above the 40 cm layer under SL was 0.0097, being significantly higher than that under SF(0.0071) by 37.23%. Salt storage under SL, SK and SF in the 40–45 cm layer accounted for 4.50, 16.92 and 7.43% of total storage in the 1-m column profile. Cumulative evaporation under SL and SF decreased significantly by 41.20 and 49.00%, with both treatments having the most significant inhibition of salt accumulation(resalinization rate being 36.06 and 47.15% lower than CK) in the 0–40 cm soil layer. In conclusion, the different forms of straw layers have desalting effects under high irrigation level(446 mm). In particular, SL and SF performed better than SK in promoting deep salt leaching and inhibiting salt accumulation on the soil surface. However, SL was simpler to implement 展开更多
关键词 straw layer segmented straw with 5 cm length straw pellet straw powder infiltration evaporation water and salt distribution
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涡扇发动机声衬的分段式设计与声模态散射分析 被引量:9
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作者 薛东文 燕群 黄文超 《科学技术与工程》 北大核心 2019年第6期270-277,共8页
针对涡扇发动机声衬开展分段式设计,并对声衬对声模态的散射作用进行了分析。应用有限元求解对流亥姆霍兹方程的方法求解了发动机短舱内的声传播,通过与试验以及高精度数值解对比验证了所应用的数值方法及声模态解耦方法;应用梯度搜索... 针对涡扇发动机声衬开展分段式设计,并对声衬对声模态的散射作用进行了分析。应用有限元求解对流亥姆霍兹方程的方法求解了发动机短舱内的声传播,通过与试验以及高精度数值解对比验证了所应用的数值方法及声模态解耦方法;应用梯度搜索法和遗传算法优化设计了4种声衬的声阻抗,结果表明可以通过长度较短的声衬实现多个目标声模态的降噪并达到降噪指标,轴向分段式相比均布式声衬和周向分布式声衬具有更大的降噪量;此外还对分段式声衬的声模态散射现象进行了分析,分析了声衬对声波的模态散射。研究结果表明最优声衬产生的反射声功率要大于通过声衬传递的声功率,周向分段的声衬散射形成了更低阶声模态。建议应用轴向分段式声衬降低风扇前传噪声。 展开更多
关键词 声模态 散射 分段式 声衬 优化
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考虑故障影响的电动汽车充电系统控制策略的研究 被引量:9
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作者 陈磊 黄琦 +1 位作者 张昌华 田佳燊 《电力系统保护与控制》 EI CSCD 北大核心 2012年第7期117-122,共6页
模糊自适应PID控制方法的应用,解决了常规PID控制方法过分依赖于被控系统精确数学模型的问题。对于电动汽车充电系统,模糊自适应PID控制方法的抗故障能力并不突出。针对该问题,建立了充电系统的近似数学模型,讨论了常见故障对系统的影响... 模糊自适应PID控制方法的应用,解决了常规PID控制方法过分依赖于被控系统精确数学模型的问题。对于电动汽车充电系统,模糊自适应PID控制方法的抗故障能力并不突出。针对该问题,建立了充电系统的近似数学模型,讨论了常见故障对系统的影响,提出了一种分段式模糊自适应PID控制方法,给出了基于这种控制方法的相关参数的整定规则。Matlab仿真结果表明:这种控制策略的效果是显著的,与传统的模糊自适应PID控制方法相比,它具有更好的动静态性能和更强的抗故障能力。 展开更多
关键词 电动汽车 充电系统 模糊自适应PID 分段式 抗故障
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基于二阶分段式的Apriori算法优化 被引量:8
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作者 刘丽娜 吴新玲 《计算机工程与设计》 北大核心 2021年第7期1940-1947,共8页
针对数据的复杂多样性以及Apriori算法的低效问题,提出依托Spark计算框架的二阶分段式算法优化模型。基于K-Means方法设计并行聚类分析算法,采用该算法对多维多属性值数据类型进行聚类分析,提高数据差异性,降低数据规模。通过“字典表... 针对数据的复杂多样性以及Apriori算法的低效问题,提出依托Spark计算框架的二阶分段式算法优化模型。基于K-Means方法设计并行聚类分析算法,采用该算法对多维多属性值数据类型进行聚类分析,提高数据差异性,降低数据规模。通过“字典表”化存储模式压缩数据量,采用“与”操作降低I/O和去候选频繁项集优化Apriori算法,利用优化后的Apriori算法挖掘聚类后数据的关联规则。通过算法分析及实验验证,当数据量达到“拐点”时优化后的算法模型相对于原Apriori算法执行效率提高47%以上,且不受数据复杂度和噪声影响,提高了规则的形成效率和鲁棒性。 展开更多
关键词 关联规则 聚类分析 分段式 算法优化 多维多属性值
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分段式分层深松后铲设计与试验 被引量:8
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作者 赵淑红 杨超 +2 位作者 杨罗罗 高连龙 杨悦乾 《东北农业大学学报》 CAS CSCD 北大核心 2019年第12期86-96,共11页
垄作秸秆还田条件下,为降低底层土壤扰动量,提高表层秸秆扰动入垄沟量,设计一种分段式分层深松后铲。分段式分层深松后铲下段铲柄为圆弧形,通过滑推分析和铲柄与秸秆相互作用力学分析设计上段铲柄。为验证设计合理性,应用EDEM软件分析... 垄作秸秆还田条件下,为降低底层土壤扰动量,提高表层秸秆扰动入垄沟量,设计一种分段式分层深松后铲。分段式分层深松后铲下段铲柄为圆弧形,通过滑推分析和铲柄与秸秆相互作用力学分析设计上段铲柄。为验证设计合理性,应用EDEM软件分析所设计分层深松铲与普通分层深松铲对于底层土壤和表层秸秆扰动规律。通过分析分层深松对于土壤与秸秆扰动位移确定试验因素,运用4因素3水平正交试验方法,以前铲铲尖类型、后铲铲尖类型、前后铲间距和前进速度为影响因素,以底层土壤扰动率和秸秆入垄沟率为评价指标,对设计分层深松铲作田间优化试验。结果表明,前铲铲尖为双翼型、后铲铲尖为凿型、前后铲间距为300 mm、前进速度为3km·h-1时设计分层深松铲作业效果最优。优化设计分层深松铲与普通分层深松铲田间性能对比试验结果表明,优化设计分层深松铲整体性能更优,满足垄作秸秆还田条件下耕作要求,可为分层深松铲设计与优化提供借鉴。 展开更多
关键词 分段式 分层深松 底层土壤扰动 秸秆扰动
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Design of a wide-field target detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance 被引量:7
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作者 于清华 武冬梅 +1 位作者 陈福春 孙胜利 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第7期34-39,共6页
Detecting and tracking multiple targets simultaneously for space-based surveillance requires multiple cameras,which leads to a large system volume and weight. To address this problem, we propose a wide-field detection... Detecting and tracking multiple targets simultaneously for space-based surveillance requires multiple cameras,which leads to a large system volume and weight. To address this problem, we propose a wide-field detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance. This study realizes two operating modes by changing the working paired lenslets and corresponding waveguide arrays: a detection mode and a tracking mode. A model system was simulated and evaluated using the peak signal-to-noise ratio method. The simulation results indicate that the detection and tracking system can realize wide-field detection and narrow-field, multi-target, high-resolution tracking without moving parts. 展开更多
关键词 FOV Design of a wide-field target detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance
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分段式积极护理元素整合干预法在腹腔镜胰十二指肠切除术患者中的应用 被引量:7
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作者 张静 《齐鲁护理杂志》 2016年第22期22-24,共3页
目的:探讨分段式积极护理元素整合干预法在腹腔镜胰十二指肠切除术患者中的应用方法和效果。方法:将行腹腔镜胰十二指肠切除术的60例患者随机分为对照组和观察组各30例,对照组实施常规围术期护理,观察组实施分段式积极护理元素整合干预... 目的:探讨分段式积极护理元素整合干预法在腹腔镜胰十二指肠切除术患者中的应用方法和效果。方法:将行腹腔镜胰十二指肠切除术的60例患者随机分为对照组和观察组各30例,对照组实施常规围术期护理,观察组实施分段式积极护理元素整合干预法,比较两组患者干预后负性情绪阳性率、总疼痛率、并发症发生率及护理服务满意度。结果:观察组患者干预后负性情绪阳性率、总疼痛率及并发症发生率均显著低于对照组,护理服务满意度显著高于对照组(P<0.05)。结论:分段式积极护理元素整合干预法能够保证患者最大程度的身心舒适,提高护理安全性和护理服务满意度。 展开更多
关键词 分段式 积极护理元素整合干预法 腹腔镜 胰十二指肠切除术
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Theoretical analysis of a new segmented anchoring style in weakly cemented soft surrounding rock 被引量:7
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作者 Zhao Zenghui Wang Weiming Wang Lihua 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第3期401-407,共7页
According to the tensile failure of rock bolt in weakly cemented soft rock, this paper presents a new segmented anchoring style in order to weaken the cumulative effect of anchoring force associated with the large def... According to the tensile failure of rock bolt in weakly cemented soft rock, this paper presents a new segmented anchoring style in order to weaken the cumulative effect of anchoring force associated with the large deformation. Firstly, a segmented mechanical model was established in which free and anchoring section of rock bolt were respectively arranged in different deformation zones. Then, stress and displacement in elastic non-anchoring zone, elastic anchoring zone, elastic sticking zone, softening sticking zone and broken zone were derived respectively based on neural theory and tri-linear strain softening constitutive model of soft rock. Results show that the anchoring effect can be characterized by a supporting parameter b. With its increase, the peak value of tangential stress gradually moves to the roadway wall, and the radial stress significantly increases, which means the decrease of equivalent plastic zone and improvement of confining effect provided by anchorage body. When b increases to 0.72, the equivalent plastic zone disappears, and stresses tend to be the elastic solutions. In addition, the anchoring effect on the displacement of surrounding rock can be quantified by a normalization factor δ. 展开更多
关键词 Weakly cemented soft rock segmented anchorage Strain softening Analytical model
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Bioinspired Segment Robot with Earthworm-like Plane Locomotion 被引量:5
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作者 Chang-Woo Song Dong-Jun Lee Seung-Yop Lee 《Journal of Bionic Engineering》 SCIE EI CSCD 2016年第2期292-302,共11页
In this paper, a miniaturized segment robot using solenoids is developed to mimic the plane locomotion of earthworms. The bioinspired robot is composed of five segmented bodies, and one segment has two solenoid actuat... In this paper, a miniaturized segment robot using solenoids is developed to mimic the plane locomotion of earthworms. The bioinspired robot is composed of five segmented bodies, and one segment has two solenoid actuators. This robot can move linearly and it can also turn due to the pair of solenoid actuators that facilitate the earthworm-like peristaltic locomotion. We have designed a miniaturized solenoid with a permanent magnet plunger in order to increase the total electromagnetic force. A theoretical analysis is performed to predict the linear and turning motions of each segment, and the optimal profiles of input signals are obtained for fast locomotion. Experiments are then conducted to determine the linear and turning motions of the segment robot. It takes about 0.5 s for the five segments to complete one cycle of the peristaltic locomotion. In experiments, the segment robot is shown to have the linear and angular velocities of 27.2 mm·s^-1 (0.13 body-length per second) and 2 degrees per second, respectively. 展开更多
关键词 bioinspired robot EARTHWORM peristaltic locomotion SOLENOID segmented robot
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Analysis of the Effect of High-Dose Segmental Citrate Anticoagulation in High Flux Hemodialysis
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作者 Xubo Fu 《Journal of Clinical and Nursing Research》 2024年第5期95-99,共5页
Objective:To analyze the clinical effect of high-dose citrate in segmental extracorporeal anticoagulation for high-throughput hemodialysis.Methods:The subjects included in this study were admitted to the hospital for ... Objective:To analyze the clinical effect of high-dose citrate in segmental extracorporeal anticoagulation for high-throughput hemodialysis.Methods:The subjects included in this study were admitted to the hospital for maintenance hemodialysis treatment from January 2021 to January 2023.All patients had a high risk of bleeding and received 4%trisodium citrate anticoagulant treatment,administered at a rate of 200 mL/h before and after the dialyzer.The anticoagulant effects achieved by the patients were observed and analyzed.Results:The total number of patients who received high-dose segmented citrate extracorporeal anticoagulation dialysis treatment was 50,with each patient undergoing 100 treatments.During the treatment,2 patients had to end the treatment early due to transmembrane pressure exceeding 30 mmHg and an increase in venous pressure exceeding 250 mmHg;the treatment times for these patients were 20 minutes and 200 minutes,respectively.The remaining patients successfully completed the 4-hour treatment.Blood pH and calcium ion concentration in the venous pot were monitored.It was observed that before dialysis,after 2 hours of dialysis,and at the end of dialysis,the blood pH of the patients remained within a relatively normal range.Although some patient levels changed after dialysis,they remained within the normal range.No adverse reactions(such as numbness of the limbs or convulsions)were observed during the anticoagulant treatment.Conclusion:Administering 4%trisodium citrate at a rate of 200 mL/h before and after the dialyzer achieves a good anticoagulant effect,maintains the patient’s blood gas levels within the normal range at the end of dialysis,and causes no adverse reactions. 展开更多
关键词 High dose segmented citrate High flux HEMODIALYSIS Anticoagulation effect
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一种基于分段电阻的低功耗电流舵DAC
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作者 刘照 赵俊杰 +3 位作者 钟国强 徐宁 杨吉城 常玉春 《微电子学》 CAS 北大核心 2024年第2期171-176,共6页
基于SMIC 180 nm标准CMOS工艺,设计了一款面积仅为320μm×150μm的10 bit分段式电流舵数模转换器(DAC)。该设计采用“5+5”式分段,通过电阻实现高位子DAC的量化阶梯,从而减小高位子DAC所需电流。与原始的电阻量化结构相比,改变电... 基于SMIC 180 nm标准CMOS工艺,设计了一款面积仅为320μm×150μm的10 bit分段式电流舵数模转换器(DAC)。该设计采用“5+5”式分段,通过电阻实现高位子DAC的量化阶梯,从而减小高位子DAC所需电流。与原始的电阻量化结构相比,改变电流流向,节约了一半的电流源数量。同时通过校准电阻的方式,有效校准了结构中存在的特殊非理想特性。仿真验证结果表明,本分段电流舵DAC微分非线性(DNL)和积分非线性(INL)最大值分别为0.09 LSB和0.34 LSB,无散杂动态范围为64.52 dB,功耗为8.58 mW。与传统结构相比,该结构面积减小约80%,有效减小分段式电流舵DAC的功耗以及面积。 展开更多
关键词 分段式 电流舵DAC 低功耗 校准
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晶圆搬运小车非接触式供电系统的设计与试验
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作者 周志红 李曦 +4 位作者 王斌斌 程健 陈江春 马学军 徐恢川 《湖北理工学院学报》 2024年第4期1-4,共4页
传统AGV有线供电方式存在布线繁琐、限制移动范围等问题,严重影响了AGV工作效率。文章基于现有非接触式供电技术基础,设计分段式非接触式供电装置,并进行系统测试和验证,发现其用电量仅为无接触式未分块供电系统的58.49%。该设计可为AG... 传统AGV有线供电方式存在布线繁琐、限制移动范围等问题,严重影响了AGV工作效率。文章基于现有非接触式供电技术基础,设计分段式非接触式供电装置,并进行系统测试和验证,发现其用电量仅为无接触式未分块供电系统的58.49%。该设计可为AGV小车的高效、节能的无线供电提供新的思路。 展开更多
关键词 分段式 非接触式供电 无人搬运小车 设计
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Improved Segmented Belief Propagation List Decoding for Polar Codes with Bit-Flipping
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作者 Mao Yinyou Yang Dong +1 位作者 Liu Xingcheng Zou En 《China Communications》 SCIE CSCD 2024年第3期19-36,共18页
Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved s... Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes. 展开更多
关键词 belief propagation list(BPL)decoding bit-flipping polar codes segmented CRC
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Hybrid vibration isolation optimization of a flexible manipulator based on neural network agent model
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作者 Yongxin ZHANG Liang LI +2 位作者 Dingguo ZHANG Wei-Hsin LIAO Xian GUO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第5期482-505,共24页
Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flex... Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flexible structures.Moreover,machine learning technology is widely used in the engineering field because of its efficient multi-objective optimization.The dynamic simulation of a rotational segmental flexible manipulator system is presented,in which enhanced active constrained layer damping is carried out,and the neural network model of Genetic Algorithm-Back Propagation(GA-BP)algorithm is investigated.Vibration suppression and structural optimization of the SACLD manipulator model are studied based on vibration mode and damping prediction.The modal responses of the SACLD manipulator model at rest and rotation are obtained.In addition,the four model indices are optimized using the GA-BP neural network:axial incision size,axial incision position,circumferential incision size,and circumferential incision position.Finally,the best model for vibration suppression is obtained. 展开更多
关键词 Machine learning Vibration suppression Flexible manipulator segmented active constrained layer damping Structural optimization
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Design and Implementation of a High-Sensitivity Magnetic Sensing System Based on GMI Effect
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作者 Wenzhu Wu Ming Xu +4 位作者 Changlin Han Junquan Tang Jia Xu Lin Xu Mingxin Qin 《Journal of Beijing Institute of Technology》 EI CAS 2024年第3期237-247,共11页
A high-sensitivity magnetic sensing system based on giant magneto-impedance(GMI)effect is designed and fabricated.The system comprises a GMI sensor equipped with a gradient probe and an signal acquisition and processi... A high-sensitivity magnetic sensing system based on giant magneto-impedance(GMI)effect is designed and fabricated.The system comprises a GMI sensor equipped with a gradient probe and an signal acquisition and processing module.A segmented superposition algorithm is used to increase target signal and reduce the random noise.The results show that under unshielded,room temperature conditions,the system achieves successful detection of weak magnetic fields down to 2 pT with a notable sensitivity of 1.84×10^(8)V/T(G=1000).By applying 17 overlays,the segmented superposition algorithm increases the power proportion of the target signal at 31 Hz from6.89%to 45.91%,surpassing the power proportion of the 2 Hz low-frequency interference signal.Simultaneously,it reduces the power proportion of the 20 Hz random noise.The segmented superposition process effectively cancels out certain random noise elements,leading to a reduction in their respective power proportions.This high-sensitivity magnetic sensing system features a simple structure,and is easy to operate,making it highly valuable for both practical applications and broader dissemination. 展开更多
关键词 HIGH-SENSITIVITY magnetic field sensing system GMI effect segmented superposition algorithm
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Migratable Power System Transient Stability AssessmentMethod Based on Improved XGBoost
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作者 Ying Qu Jinhao Wang +4 位作者 Xueting Cheng Jie Hao Weiru Wang Zhewen Niu Yuxiang Wu 《Energy Engineering》 EI 2024年第7期1847-1863,共17页
The data-driven transient stability assessment(TSA)of power systems can predict online real-time prediction by learning the temporal features before and after faults.However,the accuracy of the assessment is limited b... The data-driven transient stability assessment(TSA)of power systems can predict online real-time prediction by learning the temporal features before and after faults.However,the accuracy of the assessment is limited by the quality of the data and has weak transferability.Based on this,this paper proposes a method for TSA of power systems based on an improved extreme gradient boosting(XGBoost)model.Firstly,the gradient detection method is employed to remove noise interference while maintaining the original time series trend.On this basis,a focal loss function is introduced to guide the training of theXGBoostmodel,enhancing the deep exploration of minority class samples to improve the accuracy of the model evaluation.Furthermore,to improve the generalization ability of the evaluation model,a transfer learning method based on model parameters and sample augmentation is proposed.The simulation analysis on the IEEE 39-bus system demonstrates that the proposed method,compared to the traditional machine learning-based transient stability assessment approach,achieves an average improvement of 2.16%in evaluation accuracy.Specifically,under scenarios involving changes in topology structure and operating conditions,the accuracy is enhanced by 3.65%and 3.11%,respectively.Moreover,the model updating efficiency is enhanced by 14–15 times,indicating the model’s transferable and adaptive capabilities across multiple scenarios. 展开更多
关键词 Transient stability assessment DATA-DRIVEN segmented focusing approximation PORTABILITY
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Design and Optimization of Segmented PM Consequent Pole Hybrid Excited Flux Switching Machine for EV/HEV Application 被引量:6
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作者 Wasiq Ullah Faisal Khan Muhammad Umair 《CES Transactions on Electrical Machines and Systems》 CSCD 2020年第3期206-214,共9页
Hybrid Excited Flux Switching Machines(HEFSMs)unique feature of high torque density(T_(den))of Permanent Magnet(PM)machines and flux regulation capability of wound field excitation machines.Due to aforesaid unique fea... Hybrid Excited Flux Switching Machines(HEFSMs)unique feature of high torque density(T_(den))of Permanent Magnet(PM)machines and flux regulation capability of wound field excitation machines.Due to aforesaid unique features,stator active HEFSMs are preferred for EV/HEV applications.In this paper a new Segmented PM Consequent Pole HE-FSM(SPMCPHEFSM)with flux bridge is proposed for EV/HEV.The developed SPMCPHEFSM exhibits improved flux modulation and flux regulation capability at reduced PM usage(suppressed PM volume by 46.52%and PM cost by 46.48%)and eliminating stator leakage flux.First,SPMCPHEFSM is geometric optimized(GO)for investigating influence of leading design with key performance indicators such as flux linkage(Ф_(pp)),average torque(T_(avg)),cogging torque(T_(cog)),T_(den),average power(P_(avg))and power density(P_(den))and then proceeded optimized model to structure modification for optimal stator design and position of field excitation coils(FEC).Comprehensive performance analysis reveals that the developed SPMCPHEFSM show improvedФ_(pp)maximum up to 9.11%,improved T_(avg)maximum up to 23.63%,truncate T_(cog)up to 18.9%whereas T_(den)and P_(den)are boost up to 23.55%and 89.72%respectively. 展开更多
关键词 Electric Vehicle Hybrid Electric Vehicle Consequent Pole Finite Element Analysis Optimization segmented PM
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The impact of segment dilution on the magnetic and hysteretic properties of ferrimagnetic (1/2-1) segmented Ising nanowire
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作者 Ersin Kantar 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第7期145-155,共11页
This study explores the presence of diverse phase diagrams and hysteresis characteristics,as well as their dependencies on segment dilution,in an Ising-type core/shell segmented nanostructure.The magnetic and hysteret... This study explores the presence of diverse phase diagrams and hysteresis characteristics,as well as their dependencies on segment dilution,in an Ising-type core/shell segmented nanostructure.The magnetic and hysteretic behavior of the nanostructure was carefully investigated by employing the effective-field theory and its respective diluted parameters.The phase diagrams reveal characteristic phenomena that are influenced by the dilution parameters.Specifically,this study examined the variations in phase transitions and tricritical points by altering the dilution and physical parameters of the segments.The investigation also encompasses an examination of the hysteresis characteristics,including the hysteresis loop,coercivity,and remanence,in relation to the segment dilution dependence of the segmented nanowire.It was discovered that as the temperature rises,the hysteresis loop areas diminish.However,intriguingly,at specific dilution and crystal area values,the hysteresis loop areas exhibit an augmentation. 展开更多
关键词 segmented nanowire effective-field theory diluted effect phase diagrams hysteresis characteristics
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