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差异散射多次波自适应消减法研究 被引量:3
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作者 赵悦伊 刘洋 +1 位作者 刘财 冯晅 《世界地质》 CAS CSCD 2012年第2期399-405,共7页
在海上地震资料处理过程中,反射多次波和散射多次波同时存在于地震资料中。由于散射多次波相对于反射多次波的能量弱,且具有时空非稳态特征,难以在常规SRME方法中去除,影响进一步的数据分析工作。将含有这两种多次波的地震数据进行分离... 在海上地震资料处理过程中,反射多次波和散射多次波同时存在于地震资料中。由于散射多次波相对于反射多次波的能量弱,且具有时空非稳态特征,难以在常规SRME方法中去除,影响进一步的数据分析工作。将含有这两种多次波的地震数据进行分离并分别做SRME多次波预测,通过自适应衰减方法有效地匹配不同类型多次波,尤其是非稳态的散射多次波。通过sigsbee2B模型的试算,经对比理想无多次波影响的地震数据资料,表明该方法可以有效地同时消除反射多次波和差异散射多次波。 展开更多
关键词 反射多次 差异散射多次 非稳态自适应相减 表层相关多次消除
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两种型号心电图机R波振幅差异的探讨
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作者 仲崇斐 李振华 +2 位作者 于文江 王春雨 孙海涛 《实用心电学杂志》 2001年第6期468-469,共2页
目的 了解不同型号心电图机其心电图R波振幅的差异 ,提高心电对疾病诊断的准确性。方法 对 40 8例病人 ,采取同一病人 ,同一时间 ,同一部位 ,同一医生操作 ,以日本光电 -65 11型单导仪描记 ,R波振幅在正常范围内作为对照组 ,日本光电8... 目的 了解不同型号心电图机其心电图R波振幅的差异 ,提高心电对疾病诊断的准确性。方法 对 40 8例病人 ,采取同一病人 ,同一时间 ,同一部位 ,同一医生操作 ,以日本光电 -65 11型单导仪描记 ,R波振幅在正常范围内作为对照组 ,日本光电842 0型 12导联同步仪描记 ,作为观察组 ,对两组同一导联R波振幅测定对比。计量资料取 x±s,作t检验。结果 两者R波振幅比值对比 ,有明显差异。 12导联同步心电图与单导联R波振幅测定对比 ,有非常显著意义 (P <0 0 0 1)。结论 两者有明显差异 ,了解两者的差异 ,防止错误的诊断 。 展开更多
关键词 12导联同步心电图 单导联心电图 R振幅差异 心电图机
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中国大陆四周强震P波速度差异的比较分析
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作者 苏国君 苏金蓉 张高华 《四川地震》 2007年第3期33-36,共4页
选择中国大陆周边不同部位的6个7级以上强震,以中国地震台网报告定位参数为准,作P波时距曲线,比较它们的速度大小,结果证实:南北方向的地震无明显差异,而东西方向上,主要是青藏高原以西的巴基斯坦强震的P波速度要明显大一些。但是,对于... 选择中国大陆周边不同部位的6个7级以上强震,以中国地震台网报告定位参数为准,作P波时距曲线,比较它们的速度大小,结果证实:南北方向的地震无明显差异,而东西方向上,主要是青藏高原以西的巴基斯坦强震的P波速度要明显大一些。但是,对于成都地震遥测台网远震速报定位的影响不会超过允许的误差范围。 展开更多
关键词 中国大陆四周的强震 P速度差异
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老年性聋患者不同刺激模式下失匹配负波特征分析 被引量:4
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作者 李宝环 李富德 +3 位作者 林鹏 梁瑞敏 陈晨 张静平 《听力学及言语疾病杂志》 CAS CSCD 北大核心 2013年第1期41-44,共4页
目的观察老年性聋(presbycusis)患者频率差异及持续时间差异失匹配负波(mismatch negativity,MMN)的特征。方法应用美国智听公司SmartEP诱发电位系统,采用被动的Oddball模式对30例老年性聋患者(老年性聋组)、26名老年听力正常者(老年听... 目的观察老年性聋(presbycusis)患者频率差异及持续时间差异失匹配负波(mismatch negativity,MMN)的特征。方法应用美国智听公司SmartEP诱发电位系统,采用被动的Oddball模式对30例老年性聋患者(老年性聋组)、26名老年听力正常者(老年听力正常组)和30名正常青年人(对照组)进行频率差异MMN和持续时间差异MMN检测。结果老年性聋组频率差异MMN潜伏期(202.53±33.75ms)与老年听力正常组(182.48±36.44ms)及对照组(174.23±41.19ms)相比明显延长(P<0.05),而波幅(4.89±1.52μV)与老年听力正常组(5.02±1.63μV)及对照组(5.54±1.58μV)相比差异无统计学意义(P>0.05),老年听力正常组频率差异MMN的潜伏期、波幅与对照组比较差异无统计学意义(P>0.05);老年性聋组持续时间差异MMN潜伏期(243.65±19.40ms)与老年听力正常组(216.47±30.89ms)及对照组(184.68±43.16ms)比较差异均有显著统计学意义(P<0.05),波幅(4.39±1.03μV)与对照组(5.32±1.97μV)比较差异有显著统计学意义(P<0.05),与老年听力正常组(4.73±1.78μV)比较差异无统计学意义(P>0.05);另外,老年性聋组频率差异MMN的潜伏期较持续时间差异MMN潜伏期短(P<0.05),频率差异MMN波幅与持续时间差异MMN波幅差异无统计学意义(P>0.05),老年听力正常组频率差异MMN的潜伏期较持续时间差异MMN潜伏期短(P<0.05),波幅差异无统计学意义(P>0.05),对照组频率差异MMN与持续时间差异MMN潜伏期及波幅差异均无显著统计学意义。结论老年性聋组频率差异及持续时间差异MMN的潜伏期较老年听力正常组及对照组延长,其波幅较对照组小,提示老年性聋患者听皮层可能发生了可塑性变化;老年性聋组持续时间差异MMN与频率差异MMN相比潜伏期长,提示持续时间差异MMN较频率差异MMN更敏感,能够更早的反映其皮层及皮层下的变化。 展开更多
关键词 老年性聋 失匹配负 频率差异失匹配负 持续时间差异失匹配负
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一种改进的中值滤波方法 被引量:22
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作者 袁勇 张固澜 《成都理工大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第2期125-129,共5页
探讨一种改进的中值滤波法进行VSP资料波场分离。从常规中值滤波的数学原理入手,详细探讨了一种改进的中值滤波法,使其在边界(L-1)/2个采样点的滤波效果与常规的中值滤波结果相同,而在对中间的各样点进行滤波时,将常规的中值滤波结果也... 探讨一种改进的中值滤波法进行VSP资料波场分离。从常规中值滤波的数学原理入手,详细探讨了一种改进的中值滤波法,使其在边界(L-1)/2个采样点的滤波效果与常规的中值滤波结果相同,而在对中间的各样点进行滤波时,将常规的中值滤波结果也参与到滤波过程中。通过对理论数据和2个零偏VSP资料进行波场分离,及对比分析分离后的波场,结果表明,改进的中值滤波相对于传统的中值滤波具有很高的稳健性和适应性。 展开更多
关键词 激发子差异 变级间距 中值滤 零偏VSP
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前庭刺激对人脑事件相关电位的影响 被引量:1
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作者 杨立军 单希征 《中华耳科学杂志》 CSCD 北大核心 2015年第2期288-292,共5页
目的本研究采用事件相关电位(ERPs)技术探讨前庭刺激对人脑加工功能的影响。方法选取15名健康男子进行实验。实验中受试者坐于转椅上,在下述条件下完成视觉操作任务:(1)实验测试,(2)对照测试,同时记录原始脑电资料。结果前庭刺激后,结... 目的本研究采用事件相关电位(ERPs)技术探讨前庭刺激对人脑加工功能的影响。方法选取15名健康男子进行实验。实验中受试者坐于转椅上,在下述条件下完成视觉操作任务:(1)实验测试,(2)对照测试,同时记录原始脑电资料。结果前庭刺激后,结果显示CPZ和PZ位置得到的差异波振幅均可见有显著性的改变,在前庭刺激后均明显减小。结论前庭刺激对人体的其他功能产生了明显影响,受试者在对视觉信号的感知时,特别是对需要选择的信号,明显产生了抑制现象。 展开更多
关键词 前庭刺激 脑功能 事件相关电位 差异波 选择性注意
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视觉工作记忆负载对偏差干扰调控的ERP研究
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作者 李毕琴 张明 胡竹菁 《心理学探新》 CSSCI 2014年第4期306-310,共5页
采用事件相关电位技术(ERPs),对听视跨通道不同工作记忆负载下偏差干扰效应的加工机制进行研究。当视觉线索50%时,比较有无工作记忆负载条件下偏差干扰效应,分析偏差刺激与标准刺激诱发的差异波,结果发现:(1)存在工作记忆负载和偏差干... 采用事件相关电位技术(ERPs),对听视跨通道不同工作记忆负载下偏差干扰效应的加工机制进行研究。当视觉线索50%时,比较有无工作记忆负载条件下偏差干扰效应,分析偏差刺激与标准刺激诱发的差异波,结果发现:(1)存在工作记忆负载和偏差干扰效应;(2)有无工作记忆负载下差异波均出现明显的N1/MMN成分、NP3和RON成分;(3)差异波中N1/MMN成分的平均波幅和潜伏期均没有差异,NP3成分的平均波幅下降;RON成分在平均波幅上没有差异,潜伏期上有工作记忆负载下显著小于无工作记忆负载。研究表明视觉工作记忆负载对偏差干扰调控过程的神经机制并不会因为无关信息与相关信息间冲突竞争增强而改变。 展开更多
关键词 偏差干扰 工作记忆负载 ODDBALL 差异波
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Dependent mechanism of Chinese prepositions processing in the brain:evidence from event-related potentials
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作者 方环海 张荣萍 +3 位作者 方环非 高明阳 郑敏 孙潇羽 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第5期282-286,共5页
Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "... Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "preposition". Results Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and fight hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. Conclusion These may demonstrate that prepositions in modem Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions (or closed-class words). 展开更多
关键词 CHINESE PREPOSITIONS VERBS event-related potentials difference waves
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R/S AND WAVELET ANALYSIS ON EVOLUTIONARYPROCESS OF REGIONAL ECONOMIC DISPARITY IN CHINA DURING PAST 50 YEARS 被引量:9
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作者 XUJian-hua LUYan +1 位作者 SUFang-lin AINan-shan 《Chinese Geographical Science》 SCIE CSCD 2004年第3期193-201,共9页
This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Thei... This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Theil index sequence with different time scales. The main conclusions are: 1) The regional disparity of economic development in China, including the inter-provincial disparity, inter-regional disparity and intra-regional disparity, has existed for many years. Theil index by the comparative price has revealed the true trend for comparative disparity of regional economic development from 1952 to 2000. 2) Decomposition of Theil index indicates that the dynamic trend of comparative inter-provincial disparity in the coastal region is in line with dynamic trend of inter-provincial disparity in the whole China. 3) The R/S analysis results tell us that during 1966-1978, the Hurst exponent H=0.504 approximate to 0.5, which indicates that in that period the evolution of comparative inter-provincial disparity of economic development showed a random characteristic, and in the other periods, i.e. 1952-1965, 1979-1990 and 1991-2000, the Hurst exponent H>0.5, which indicates that in those periods the evolution of the comparative inter-provincial disparity of economic development in China had a long-enduring characteristic. 4) By using wavelet analysis at different time scale, we arrived at a conclusion that the evolutionary process of the disparity of economic development of China is not a simple inverted U shape but a compound of several U shapes. The result tells us that the evolutionary plot of inter-provincial disparity in China follows the inverted U on the whole at the higher scale, 24 ( 16 years). That is to say, the disparity tends to rise in the first stage of economic development, and fall slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 23 ( 8 years), then a link of several U shapes will appear. 展开更多
关键词 China regional economic disparity Theil index R/S analysis wavelet analysis
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Variation in the timing of river entry of Atlantic salmon (Salmo salar L.) in the Baltic
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作者 Anna KUPARINEN Juha MERIL 《Current Zoology》 SCIE CAS CSCD 北大核心 2009年第5期342-349,共8页
The timing of river entry in the Atlantic salmon is known to depend on genetic, demographic and environmental factors, but little is known about the relative magnitude of among population and among year variation and ... The timing of river entry in the Atlantic salmon is known to depend on genetic, demographic and environmental factors, but little is known about the relative magnitude of among population and among year variation and covariation in this respect in natural state Atlantic salmon rives. To investigate this, variability in the timing of river entry in three historical Finnish Atlantic salmon populations were analyzed using salmon trap data collected during 1870- 1902. The analyses reveled that 1 ) the timing of river entry differed substantially and consistently among the rivers, and that 2) variation among the rivers was much larger than variation among years. Annual variations were not explained by regional environmental conditions, whereas in one river the timing of the local flood peak was a significant predictor of the timing of river entry. Differences in the timing of salmon entry to geographically closely situated rivers suggests that a regionally fixed opening date for coastal fisheries might not be the best management strategy as it may lead to uneven exploitation of salmon populations from different rivers [ Current Zoology 55 (5) : 342 - 349, 2009] . 展开更多
关键词 Atlantic salmon Coastal fisheries Fisheries management Freshwater entry Migration River entry
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基于无线传感技术的体育教学田径训练强度监测系统 被引量:1
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作者 熊恬 《微型电脑应用》 2023年第1期177-181,共5页
针对一般监测系统只能实现运动员身体的局部状态监测,且精准度较低、信号间波频变化差异较大问题,设计基于无线传感技术的体育教学田径训练强度监测系统。凭借无线传感技术优势结合训练强度信号特征给出监测系统的整体框架,系统的外在... 针对一般监测系统只能实现运动员身体的局部状态监测,且精准度较低、信号间波频变化差异较大问题,设计基于无线传感技术的体育教学田径训练强度监测系统。凭借无线传感技术优势结合训练强度信号特征给出监测系统的整体框架,系统的外在表现形式为一种终端强度信号监测器,此装置主要由供电源、数据传感器、基于运动生理特征的信号显示器、数据采集模块以及监测电路共同组成,其中,信号监测器主要通过对运动员身体的静态肌电信号实施特征查找,并以信号特征间的数据偏差作为强度判定阈值实现检测。实验结果表明,所提系统可完成运动员训练强损伤定位,且结果准确性较高、信号间的波频变化差异较小,在外界刺激的情况下也能不受其影响、保证监测质量,整体过程中信噪比较低、测试结果误差率较小,整体性能优异。 展开更多
关键词 频变化差异 无线传感技术 生理特征 损伤定位
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Major and Minor Harmonic Keys: The Discrepancy in Chord Classification Under a Computational Tonality Analytical Method
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作者 Miroslaw Majchrzak 《Journal of Literature and Art Studies》 2013年第6期381-390,共10页
Basing upon the tonality analytic method, the present paper aims at: (1) Drawing attention to the subordination of the minor key vs. the major key in the chord classification, using the same methodology; and (2) ... Basing upon the tonality analytic method, the present paper aims at: (1) Drawing attention to the subordination of the minor key vs. the major key in the chord classification, using the same methodology; and (2) Showing the differences for the major key and the minor (harmonic) key in the classification of chords, as an aspect of importance for interpreting a piece's tonal structure diagram. The relations between chords appearing in the major and minor (harmonic) key will be shown by applying the comparisons of: (1) third-based chords; and (2) degrees in the C major and A minor keys, on which the same diatonic chords appear. 展开更多
关键词 TONALITY MODES classification of diatonic chords methodology
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Semantic Differential as an Assessment Tool of (Dis) Advantages of QMS in the Light of Accredited Certification in Poland
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作者 Katarzyna Hys Liliana Hawrysz 《Chinese Business Review》 2014年第1期42-52,共11页
This article is a continuation of the issue in the field of assessment of (dis)advantages resulting from the implementation of the quality management systems (QMS) in a structure of the organization. The publicati... This article is a continuation of the issue in the field of assessment of (dis)advantages resulting from the implementation of the quality management systems (QMS) in a structure of the organization. The publication uses the results of studies conducted in the range of assessment's information completeness provided by the certification bodies (CBs) in the context of advantages and disadvantages of the QMS implementation in accordance with PN-EN ISO 9001. In addition, an attempt to define a tool for the QMS assessment of (dis)advantages in the organization has been made. The basis for empirical analysis of the issue was the information provided by an accredited management systems CBs recommended by the Polish Centre for Accreditation (PCA). There are 33 units in Poland, which were granted by PCA with the accreditation within the range of ISO 9001:2008. In the first stage of the research work, a substantive analysis of websites content among mentioned CBs has been carried out. In addition, the paper proposes use of semantic differential method (SD) to evaluate (dis)advantages of the QMS. SD adaptation for the assessment of the QMS (dis)advantages is the authorial concept. The authors hope for polemic in this area. In the face of obtained results, an authorial SD construction has been proposed, which is useful and may help in the formulation and conveying of the relevant (reliable) information to potential clients in the range of (dis)advantages resulting from the QMS implementation to the organization. As a consequence, the recommendations have been set, which are kind of guidelines that could significantly influence the realignment of the information state conveyed on the internet by the CBs. 展开更多
关键词 quality management system (QMS) accredited units (dis)advantages form the QMS implementation semantic differential (SD)
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Analysis of Price and Industry Dynamics of Sustainable and Specialty Coffee in Costa Rica
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作者 Bemard Kilian Lloyd Rivera 《Journal of Agricultural Science and Technology(B)》 2014年第5期375-385,共11页
Volatility of commodity prices has affected dramatically the coffee industry in recent years, particularly small holder farmers. Differentiation of coffee through certification, such as sustainahility and quality attr... Volatility of commodity prices has affected dramatically the coffee industry in recent years, particularly small holder farmers. Differentiation of coffee through certification, such as sustainahility and quality attributes, has been proposed as a strategy for protection of the farmers against volatility in the international prices. This research paper evaluated three different models to explore the effectiveness of the differentiation strategies in protecting the farmer against price volatility in recent years, focusing on the case of Costa Rica. Evidence showed important differences in the price dynamics over time when comparing three groups of coffee. 展开更多
关键词 Commodity prices price volatility sustainable development coffee prices.
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