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2001年3月2日磁通量传输事件特性的研究 被引量:4
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作者 左平兵 刘绍亮 +2 位作者 金曙平 刘振兴 史建魁 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2004年第3期376-384,共9页
20 0 1年 3月 2日 1 1 :0 0至 1 1 :1 5UT期间 ,ClusterⅡ在南半球极尖区晨侧附近磁鞘内探测到 3个通量传输事件 (简称FTEs) .本文利用ClusterⅡ星簇 4颗卫星观测到的磁场和等离子体资料研究了这些通量传输事件的磁场形态和粒子特征 .... 20 0 1年 3月 2日 1 1 :0 0至 1 1 :1 5UT期间 ,ClusterⅡ在南半球极尖区晨侧附近磁鞘内探测到 3个通量传输事件 (简称FTEs) .本文利用ClusterⅡ星簇 4颗卫星观测到的磁场和等离子体资料研究了这些通量传输事件的磁场形态和粒子特征 .并利用它们探测到的空间磁场梯度资料由安培定律直接求出星簇所在区域的电流分布 .结果指出 :(1 )BY 占优势的行星际磁场结构在磁层顶的重联可以在极尖区附近发生 ;(2 )FTEs通量管形成初期内外总压差和磁箍缩应力不一定平衡 ,达到平衡有一发展过程 ;(3)FTEs通量管截面在L M平面内的线度约为 1 .89RE;(4 )FTEs通量管中等离子体主要沿轴向场方向流动 ,整个通量管以慢于背景等离子体的速度沿磁层顶向南向尾运动 ;(5 )FTEs通量管中不仅有轴向电流 ,也存在环向电流 .轴向电流基本沿轴向磁场方向流动 .轴向和环向电流在管内均呈体分布 ,因而轴向电流产生的环向磁场接近管心时不断减小到零 ,而环向电流生成的轴向场则不断增大到极值 ;(6 )在通量管的磁鞘部分观测到磁层能量粒子流量的增强 ,这表明通量管通过磁层顶将磁鞘和磁层内部连通起来了 . 展开更多
关键词 2001年 磁通量传输事件特性 等离子体 空间磁场梯度资料 磁场重联 磁层亚暴
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论奢侈品牌的事件管理模型和特性 被引量:1
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作者 李杨 范徵 《上海管理科学》 CSSCI 2013年第1期33-37,共5页
随着中国奢侈品消费市场的不断扩大,奢侈品牌的竞争也愈发激烈。如何通过事件管理来实现品牌的营销目标逐渐成为每个奢侈品牌关注的焦点,也成为学术界探索的新领域。本文基于事件管理6S EVENTS模型,研究和分析了大量奢侈品牌的事件管理... 随着中国奢侈品消费市场的不断扩大,奢侈品牌的竞争也愈发激烈。如何通过事件管理来实现品牌的营销目标逐渐成为每个奢侈品牌关注的焦点,也成为学术界探索的新领域。本文基于事件管理6S EVENTS模型,研究和分析了大量奢侈品牌的事件管理案例,并结合奢侈品牌行业内的调查研究,提出了奢侈品牌的事件营销模型,指出了奢侈品牌在事件管理中必须具备的EVENTS特性,为中国奢侈品牌的营销研究和事件管理提供了坚实的基础。 展开更多
关键词 事件管理 事件营销 奢侈品牌事件特性
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钢琴音乐转写中音乐相关特性研究
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作者 单小岩 张结 戴礼荣 《小型微型计算机系统》 CSCD 北大核心 2024年第10期2305-2311,共7页
自动音乐转写,即利用程序将音乐音频转写成音符的形式,是音乐信息检索的一项重要课题.目前基于深度学习的转写算法多源自语音识别、自然语言处理等领域,缺乏对音乐自身特性的深入研究.本文采用Transformer架构进行钢琴音乐转写,利用合... 自动音乐转写,即利用程序将音乐音频转写成音符的形式,是音乐信息检索的一项重要课题.目前基于深度学习的转写算法多源自语音识别、自然语言处理等领域,缺乏对音乐自身特性的深入研究.本文采用Transformer架构进行钢琴音乐转写,利用合成的音乐数据进行预训练,并设计了符合音符事件结构的截止点识别网络,旨在尝试对转写中的音乐特性进行针对性设计.本文的方法一方面利用了音乐合成技术成熟、便捷的方案,易于数据扩充;另一方面从目标检测的角度进行剖析,对音符本身的事件特性加以探讨.实验表明,本文采用合成音乐进行预训练有助于音符识别,截止点识别网络可以提高音符级的转写结果,实现了音符起点F1=97.40%,带截止点音符F1=88.81%的转写结果. 展开更多
关键词 钢琴音乐转写 TRANSFORMER 合成音乐预训练 音符事件特性 目标检测
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突发性事件发生后医院医疗器械保障体系建立的研究 被引量:1
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作者 汤黎明 吴敏 钟添萍 《医疗卫生装备》 CAS 2011年第11期104-105,共2页
通过对以往发生过的突发性事件医疗器械保障具体实践的总结和思考,提出了要主动准备、区别应对、平时养成、完备信息、打牢基础、平战结合、培养队伍的建设思路,为有效破解突发性事件急救中医疗器械供应的难题提供了较好的解决办法。
关键词 突发性 医疗器械 事件特性 训练 保障体系
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考虑换流站海量事件的关联规则挖掘分析方法 被引量:7
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作者 黄剑湘 林铮 +3 位作者 刘可真 骆钊 禹晋云 徐峰 《电力系统保护与控制》 EI CSCD 北大核心 2022年第12期117-125,共9页
为提高换流站运维人员面对海量生成事件的分析能力,提出一种考虑换流站海量事件的关联规则挖掘分析方法。首先,利用原始事件元组特性进行记录事件与响应日志的实体特征筛选,并进行换流站实体特征的布尔映射与关联挖掘建模。然后,利用互... 为提高换流站运维人员面对海量生成事件的分析能力,提出一种考虑换流站海量事件的关联规则挖掘分析方法。首先,利用原始事件元组特性进行记录事件与响应日志的实体特征筛选,并进行换流站实体特征的布尔映射与关联挖掘建模。然后,利用互信息(MI)原理与对称不确定性(SU)理论改进FP-Growth算法。最后,基于改进算法进行换流站事件关联分析,进而基于关联规则结果进行换流站异常反馈。通过挖掘昆柳龙直流换流站调试期间海量生成事件,表明所提出的方法可以有效地从海量事件中提取判断特征与结果特征的强关联规则,及时发现换流站的设备异常动作,并为运维分析提供决策支撑。 展开更多
关键词 事件元组特性 布尔映射 改进FP-Growth算法 异常反馈 昆柳龙直流换流站
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社会历史理论中的解释与因果决定论 被引量:2
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作者 谌中和 《复旦学报(社会科学版)》 CSSCI 北大核心 1999年第1期74-79,共6页
无论何种门类的知识或理论 ,都将力图为某些特定种类的现象提供解释。解释的合理性程度主要来自两个方面 :(1 )解释的逻辑结构正确 ;(2 )解释能够或已经为某种经验所证实。社会历史科学 (文化科学 )从上个世纪中叶以来围绕社会科学要不... 无论何种门类的知识或理论 ,都将力图为某些特定种类的现象提供解释。解释的合理性程度主要来自两个方面 :(1 )解释的逻辑结构正确 ;(2 )解释能够或已经为某种经验所证实。社会历史科学 (文化科学 )从上个世纪中叶以来围绕社会科学要不要采用经验科学的标准、或者说社会科学的“科学性标准”问题展开了长时间的争论。一派是科学主义派 ,坚决主张社会文化科学的科学化 ,认为经验科学的形式是科学的唯一形式 ,因而当然是文化科学应该努力追求的目标。另一派是“历史主义派”,强调文化科学处理事件的独特性。这种事件独特性必然要求方法上的独立 ,从而保证了文化科学的独立性。而且 ,自然科学的那种检验要求对文化科学也没有约束力 ,文化科学应该坚决拒斥科学主义的干涉和僭越。解释的合理性与因果性又必然地联系在一起对因果性的不同理解导致对历史本身的不同理解 展开更多
关键词 解释 特性事件 客观性 证实 因果性 决定论
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网络舆情传播与我国公共政策议程设置
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作者 万旋傲 《新媒体与社会》 2019年第2期150-166,共17页
网络舆情传播在推动社会问题进入政策议程的过程中彰显了重要力量,这其中,哪些关键因素对政策议程的形成起了主要作用,是本文关注的核心问题。基于对我国214起舆情案例的实证分析发现:网络舆情的传播热度和网络舆情的事件特性都对政策... 网络舆情传播在推动社会问题进入政策议程的过程中彰显了重要力量,这其中,哪些关键因素对政策议程的形成起了主要作用,是本文关注的核心问题。基于对我国214起舆情案例的实证分析发现:网络舆情的传播热度和网络舆情的事件特性都对政策议程的形成有显著影响。具体而言,当舆情事件所指向的公共政策可行性越高、舆情传播热度越高、政策诉求越高、有同质事件发生时,该舆情事件触发政策议程形成的概率越大。 展开更多
关键词 网络舆情 政策议程 舆情传播热度 事件特性
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对当前通信网运营中安全问题的探讨
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作者 白崇山 《电信技术》 2003年第4期29-32,共4页
以当前开放性电信网的运营为背景,结合运城通信网运行的实际,探讨了电信网的网络安全问题,阐释了电信网运行的大安全观,并以此为视角,扫视了影响网络安全运行的典型事件,分析了网络安全事件的特点,提出了对电信网安全实行分级管理的设想... 以当前开放性电信网的运营为背景,结合运城通信网运行的实际,探讨了电信网的网络安全问题,阐释了电信网运行的大安全观,并以此为视角,扫视了影响网络安全运行的典型事件,分析了网络安全事件的特点,提出了对电信网安全实行分级管理的设想,探讨了搞好网络安全、确保通信畅通的对策。 展开更多
关键词 通信网 网络安全 分级管理 对策 事件特性 大安全观
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Analysis of the Flanking Sequence and EventSpecific Detection of Transgenic Line W-4 of Brassica napus 被引量:1
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作者 陈松 申爱娟 +1 位作者 周晓婴 戚存扣 《Agricultural Science & Technology》 CAS 2014年第7期1089-1094,共6页
The genetically modified high-oleic rapeseed (Brassica napus L.) line W-4 was obtained by transforming a binary vector which harbored an inverted repeat expression cassette of fad2 gene into the rapeseed cultivar We... The genetically modified high-oleic rapeseed (Brassica napus L.) line W-4 was obtained by transforming a binary vector which harbored an inverted repeat expression cassette of fad2 gene into the rapeseed cultivar Westar.The transformation was mediated by Agrobacterium.The flanking sequences to both the left and right borders of T-DNA insertion site were amplified by thermal asymmetric interlaced PCR (TAIL-PCR) from the genomic DNA of the transgenic rapeseed line W-4.The flanking sequences to the right border was 290 bp in length and the nucleotide composition was 31.27% for G+C content while 68.73% for A+T content.The flanking sequence to the left border was 365 bp in length and the G+C content was 32.6% and the A+T content was 67.4%,indicating that the T-DNA was integrated in the A/T-rich region.Further more,sequence alignment analysis showed a deletion of 62 bp including the right border of pCNFIRnos and the integration of the whole left border except a change of G to A.That was to say,the integration of the T-DNA in the transgenic line W-4 not involved in the vector sequences.Based on both flanking sequences as well as the left and right borders of the T-DNA sequences,two pairs of specific primers TLF/TLR and TRF/TRR were designed.Using the primers the event-specific PCR detection method for transgenic rapeseed line W-4 was established.By the PCR,two fragments of 485 and 405 bp were amplified from the W-4 genomic DNA as expected,while no products were amplified from the genomic DNA of other transgenic rapeseed lines and non-transgenic rapeseed line.And by the PCR it is possible to detect the W-4 genomic DNA from a mixed sample of genomic DNA.The limit of the detection for the qualitative PCR assay was 0.1%.The method developed in this work is highly specific,sensitive and suitable for event-specific detection of the transgenic rapeseed line W-4. 展开更多
关键词 Transgenic rapeseed Flanking sequences Event-specific detection
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Seasonality of the Lagged Relationship between ENSO and the Northern Hemispheric Polar Vortex Variability 被引量:4
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作者 Ren Rong-Cai 《Atmospheric and Oceanic Science Letters》 2012年第2期113-118,共6页
<Abstract>This paper reports the seasonal feature of the relationship between ENSO and the stratospheric Polar Vortex Oscillation (PVO) variability in the Northern Hemisphere.It is shown that the lagged ENSO-PVO... <Abstract>This paper reports the seasonal feature of the relationship between ENSO and the stratospheric Polar Vortex Oscillation (PVO) variability in the Northern Hemisphere.It is shown that the lagged ENSO-PVO coupling relationship exhibits distinct seasonal feature,due to the strong seasonality of PVO and ENSO.Specifically,the PVO variability not only during winter,but also in autumn and spring months,is significantly correlated with ENSO anomalies leading by seasons;however,no significant effect of ENSO is found on the PVO variability in winter months of November and February.Although a significant ENSO effect is primarily observed when ENSO leads PVO by about one year,a significant correlation is also found between PVO in the following spring months (M +1 A +1) and ENSO anomalies in the previous autumn (A-1 S-1 O- 1 N -1) when ENSO anomalies lead by about 18 months.The significant correlation between PVO in various seasons and the corresponding ENSO anomalies leading by seasons could be explicitly verified in most of the individual years,confirming that the lagged ENSO effect can largely modulate the seasonal timescale variability of PVO.Moreover,the composite spatial patterns of the zonal-mean temperature anomalies further show that the ENSO effect on the PVO in various seasons is related to the interannual variability of the seasonal timescale PVO events. 展开更多
关键词 SEASONALITY ENSO STRATOSPHERE polar vortex
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Regional Characteristics and Causes of Haze Events in Northeast China 被引量:8
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作者 CHEN Weiwei ZHANG Shichun +5 位作者 TONG Quansong ZHANG Xuelei ZHAO Hongmei MA Siqi XIU Aijun HE Yuexin 《Chinese Geographical Science》 SCIE CSCD 2018年第5期836-850,共15页
Northeast China experiences severe atmospheric pollution, with an increasing occurrence of heavy haze episodes. However, the underlying forces driving haze formation during different seasons are poorly understood. In ... Northeast China experiences severe atmospheric pollution, with an increasing occurrence of heavy haze episodes. However, the underlying forces driving haze formation during different seasons are poorly understood. In this study, we explored the spatio-temporal characteristics and causes of haze events in Northeast China by combining a range of data sources(i.e., ground monitoring, satellite-based products, and meteorological products). It was found that the ‘Shenyang-Changchun-Harbin(SCH)'city belt was the most polluted area in the region on an annual scale. The spatial distribution of air quality index(AQI) values had a clear seasonality, with the worst pollution occurring in winter, an approximately oval-shaped polluted area around western Jilin Province in spring, and the best air quality occurring in summer and most of the autumn. The three periods that typically experienced intense haze events were Period I from mid-October to mid-November(i.e., late autumn and early winter), Period II from late-December to February(i.e., the coldest time in winter), and Period III from April to mid-May(i.e., spring). During Period I, strong PM_(2.5) emissions from seasonal crop residue burning and coal burning for winter heating were the dominant reasons for the occurrence of extreme haze events(AQI > 300). Period II had frequent heavy haze events(200 < AQI < 300) in the coldest months of January and February, which were due to high PM_(2.5) emissions from coal burning and vehicle fuel consumption, a lower atmospheric boundary layer, and stagnant atmospheric conditions. Haze events in Period III, with high PM_(10) concentrations, were primarily caused by the regional transportation of windblown dust from degraded grassland in central Inner Mongolia and bare soil in western Jilin Province. Local agricultural tilling could also release PM_(10) and enhance the levels of windblown dust from tilled soil. Better control of coal burning, fuel consumption, and crop residue burning in winter and autumn is urgently needed to address the haze problem in Northeast China. 展开更多
关键词 air quality PM10 PM2.5 dust agricultural activity coal burning fuel consumption
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Communicating Agencies' Humanitarianism in Natural Disaster and Armed Conflicts" Differences, Challenges, and Dilemmas
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作者 Carlo Piccinini 《Journalism and Mass Communication》 2014年第10期603-623,共21页
The literature on disasters mainly focuses on natural disasters and looks at their coverage by the media. The paper argues that armed conflicts are also disasters and that Western relief agencies intervening in natura... The literature on disasters mainly focuses on natural disasters and looks at their coverage by the media. The paper argues that armed conflicts are also disasters and that Western relief agencies intervening in natural disasters and conflict are also proactive communicators. Taking a different approach from much of the available research, it explores agencies' communication work in these two types of crises and analyses the differences, challenges and dilemmas that they face in communicating their humanitarianism. It outlines the distinguished inherent characteristics of natural disasters and conflicts, and examines their impact on the understanding of the crises, the perception of affected populations, and the implementation of agencies' actions. It also investigates how, in turn, all these features influence agencies' communication practices that in natural disasters emergencies and conflict-related crises perform a different role and show different parameters. In this sense, the paper distinguishes between "humanitarian communication" to refer to the former, and "humanitarian advocacy" to refer to the latter. The paper briefly explores the operational challenges engendered by the contested interpretations of humanitarian advocacy, shows that the use of the parameters of humanitarian communication in conflict-related crises to overcome these problems caused additional concern, and presents two forms of humanitarian advocacy engendering less challenges and dilemmas. 展开更多
关键词 natural disasters armed conflicts humanitarian agencies humanitarian communication humanitarianadvocacy
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Characterization of single-event multiple cell upsets in a custom SRAM in a 65 nm triple-well CMOS technology
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作者 CHEN HaiYan CHEN JianJun YAO Long 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第10期1726-1730,共5页
In this paper, the characterization of single event multiple cell upsets(MCUs) in a custom SRAM is performed in a 65 nm triple-well CMOS technology, and O(linear energy transfer(LET) = 3.1 Me V cm2/mg), Ti(LET = 22.2 ... In this paper, the characterization of single event multiple cell upsets(MCUs) in a custom SRAM is performed in a 65 nm triple-well CMOS technology, and O(linear energy transfer(LET) = 3.1 Me V cm2/mg), Ti(LET = 22.2 Me V cm2/mg) and Ge(LET = 37.4 Me V cm2/mg) particles are employed. The experimental results show that the percentage of MCU events in total upset events is 71.11%, 83.47% and 85.53% at O, Ti and Ge exposures. Moreover, due to the vertical well isolation layout, 100%(O), 100%(Ti) and 98.11%(Ge) MCU cluster just present at one or two adjacent columns, but there are still 4 cell upsets in one MCU cluster appearing on the same word wire. The characterization indicates that MCUs have become the main source of soft errors in SRAM, and even though combining the storage array interleaving distance(ID) scheme with the error detection and correction(EDAC) technique, the MCUs cannot be completely eliminated, new radiation hardened by design techniques still need to be further studied. 展开更多
关键词 multiple cell upsets (MCUs) static random access memories (SRAM) vertical well isolation radiation hardened by de-sign
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The effect of secondary structures on the generation of characteristic events during the translocation of DNA hybrid through ?-hemolysin
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作者 Xingyong Wang Yuru Li +2 位作者 Ting Li Lei Liu Hai-Chen Wu 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第1期135-141,共7页
Nanopore has been developed to be a powerful,single-molecule analytical tool for sensing ions,small organic molecules and biomacromolecules such as proteins and DNAs.Generally,the identity of the analyte can be reveal... Nanopore has been developed to be a powerful,single-molecule analytical tool for sensing ions,small organic molecules and biomacromolecules such as proteins and DNAs.Generally,the identity of the analyte can be revealed by current amplitude changes and mean dwell time of the analyte binding events.In some cases,generation of highly characteristic current events affords an alternative way of analyte determination with high confidence level.However,we found that secondary structures in DNA/RNA hybrids might severely hinder the generation of signature events during their translocation through?-hemolysin nanopore.In this report,we propose a strategy to add a certain concentration of urea in the buffer solution for single channel recordings and validate that low concentration of urea can effectively denature the secondary structures in DNA hybrids and recover the generation of signature events.This finding might be useful in other secondary structure-related nanopore sensing activities. 展开更多
关键词 nanopore sensing DNA hybrid translocation signature event urea
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