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基于可预知大客流的城市轨道交通列车加开计划调整模型与算法
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作者 易志刚 《城市轨道交通研究》 北大核心 2024年第9期18-24,共7页
[目的]节假日、大型文体活动等事件会导致城市轨道交通线路产生可预知大客流,需在确保列车运行安全的前提下,根据客流预测情况在已有列车运行图中加开列车,以期在运营成本、运营组织复杂度和乘客服务水平之间取得平衡。[方法]采用事件-... [目的]节假日、大型文体活动等事件会导致城市轨道交通线路产生可预知大客流,需在确保列车运行安全的前提下,根据客流预测情况在已有列车运行图中加开列车,以期在运营成本、运营组织复杂度和乘客服务水平之间取得平衡。[方法]采用事件-活动网络,对列车运行过程进行了形式化描述,建立了3个目标函数及相关的约束条件,进而构建了独立运用策略下列车加开计划调整模型、套跑混合运用策略下列车加开计划调整模型。在此基础上,提出了基于混合遗传禁忌的搜索算法。结合深圳地铁11号线的实际运营数据,在高峰时段和非高峰时段分别建立了不同的算例场景,以验证所建模型和算法的有效性。[结果及结论]所建模型支持不同运营时段、不同运行交路、不同车底接续策略下列车加开需求,在可预知大客流的运营调整上具有适用性。在车辆资源相对有限的情况下,为有效缓解高峰时段的客流压力,可灵活采用大小交路套跑混合运用策略,使线路的运输能力最大化。 展开更多
关键词 城市轨道交通 可预知大客流 列车加开 列车运行计划调整
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基于未来可预知特征的高速列车变流器超温故障KFF-LSTM预测方法 被引量:2
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作者 刘典 秦勇 +6 位作者 杨伟君 周伟 扈海军 杨宁 刘冰 赵鹏飞 董光磊 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2023年第8期3370-3378,共9页
提出一种基于未来可预知特征的长短期记忆网络(KFF-LSTM)长时序数据故障预测模型,引入包括动态物理量、缓变/静态物理量与恒定状态量等未来可预知特征数据进行训练,同时通过调整经典LSTM模型架构的输出门、状态更新单元以及隐变量以优... 提出一种基于未来可预知特征的长短期记忆网络(KFF-LSTM)长时序数据故障预测模型,引入包括动态物理量、缓变/静态物理量与恒定状态量等未来可预知特征数据进行训练,同时通过调整经典LSTM模型架构的输出门、状态更新单元以及隐变量以优化模型的预测准确率与及时性;最后,基于高速动车组线路运行的牵引变流器电机定子温度数据,分别以平均绝对误差(MAE)、均方根误差(RMSE)和R2分数表征回归预测准确度,以偏滞步数表征响应及时性的评价指标,对KFF-LSTM、RNN、GRU及LSTM预测模型进行消融实验及可视化对比。研究结果表明,相对于其他3种方法,提出的KFF-LSTM方法在测试集超前1~16步预测的MAE和RMSE最高可分别降低18.0%和10.8%,R2分数提升可达26.5%,在超前16步的预测偏滞步数要优于其他方法40.0%,在高速列车的长序列数据故障预警场景中具有较好的应用推广前景。 展开更多
关键词 LSTM 未来可预知特征 长时间序列 数据驱动 故障
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可预知性特殊事件下的短时交通状态预测 被引量:1
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作者 冯小原 陈咨霖 +1 位作者 季楠 任毅龙 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2023年第10期2721-2730,共10页
精准的短时交通状态预测是实施有效的交通管理与控制的重要依据。而可预知性特殊事件(PSEs)短时间内在其举办地点周边产生异常的交通出行需求,又因为事件发生数量少、数据样本收集困难等不利因素,往往造成预测精度难以保证。为此,通过... 精准的短时交通状态预测是实施有效的交通管理与控制的重要依据。而可预知性特殊事件(PSEs)短时间内在其举办地点周边产生异常的交通出行需求,又因为事件发生数量少、数据样本收集困难等不利因素,往往造成预测精度难以保证。为此,通过实测数据分析了PSEs下短时交通演化特性,在此基础上,采用改进的K近邻(KNN)算法框架,提出一种短时交通状态的KNN(PSE-KNN)预测模型,并通过基于深度强化学习的实时超参数优化方法将其构建成自适应PSE-KNN(APSE-KNN)模型,最后以北京市演唱会场景为例对所提模型的效果进行了验证。结果表明:所提模型在多步预测实验中,相对于其他7种对比预测模型,平均减少残差值12.43%、降低绝对值百分比误差29.90%。证明所提模型有优异的快速调整能力,其更适应于PSEs场景下短时交通状态预测任务。 展开更多
关键词 短时交通状态 可预知性特殊事件 K近邻 深度确定性策略梯度 强化学习
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可预涂微胶囊厌氧胶的研究进展 被引量:9
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作者 陈耀 胡孝勇 张银钟 《中国胶粘剂》 CAS 北大核心 2010年第6期54-57,共4页
可预涂微胶囊厌氧胶由于其可预涂性,在生产中具有使用方便、无污染和简化工艺等优点,近年来已成为研究重点并被广泛应用于工业领域。介绍了可预涂微胶囊厌氧胶的发展概况,重点讨论了目前国内外在可预涂微胶囊厌氧胶方面的研究成果(包括... 可预涂微胶囊厌氧胶由于其可预涂性,在生产中具有使用方便、无污染和简化工艺等优点,近年来已成为研究重点并被广泛应用于工业领域。介绍了可预涂微胶囊厌氧胶的发展概况,重点讨论了目前国内外在可预涂微胶囊厌氧胶方面的研究成果(包括可预涂微胶囊厌氧胶的组成、制备方法和应用等),并对其发展方向作了展望。 展开更多
关键词 可预 微胶囊 厌氧胶
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基于可预知事件的城市轨道交通乘务轮转计划优化调整 被引量:3
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作者 黄志远 周峰 张在龙 《交通运输系统工程与信息》 EI CSCD 北大核心 2017年第4期111-117,共7页
城市轨道交通乘务轮转计划是在充分考虑乘务员正常的夜间休息、休息日休息、休假等因素的基础上,合理安排乘务员一定阶段内的每日值乘任务.但在某日乘务轮转计划执行前,仍然会发生乘务员临时请假、临时调动等可预知事件,此时就需要对现... 城市轨道交通乘务轮转计划是在充分考虑乘务员正常的夜间休息、休息日休息、休假等因素的基础上,合理安排乘务员一定阶段内的每日值乘任务.但在某日乘务轮转计划执行前,仍然会发生乘务员临时请假、临时调动等可预知事件,此时就需要对现有乘务轮转计划进行优化调整.调整以在满足任务调整需求条件下乘务员阶段任务最均衡为目标,且调整的幅度越少越好.考虑休息日、工作量、任务连乘等约束条件,以调整后所有修改乘务任务序列的总费用最小为目标函数,建立乘务轮转计划优化调整模型,并设计基于贪婪算法和禁忌搜索算法的启发式算法进行求解.算例表明,求解算法在一定程度上实现了调整后乘务轮转计划的均衡性,达到了优化的目的. 展开更多
关键词 城市交通 优化调整 禁忌搜索算法 乘务轮转 可预知事件
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可预知事件网络新闻专题去同质化策略探究——以三大网站“天宫神九对接”专题为例 被引量:1
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作者 刘亦凡 《今传媒》 2013年第9期108-109,共2页
网络新闻专题是网络媒体在新闻领域内竞争的重要方式。由于技术手段的发展、信源获取机会的均等、网络的即时传播等特点,网络新闻专题的制作很容易趋向同质化,这一点在可预知事件新闻专题的制作中尤为明显。本文以"天宫一号与神舟... 网络新闻专题是网络媒体在新闻领域内竞争的重要方式。由于技术手段的发展、信源获取机会的均等、网络的即时传播等特点,网络新闻专题的制作很容易趋向同质化,这一点在可预知事件新闻专题的制作中尤为明显。本文以"天宫一号与神舟九号载人交会对接"事件为内容,选取主流新闻网站人民网、四大门户网站之一的新浪网及口碑新闻网站凤凰网的新闻专题作为样本,通过比较研究,分析三网站在这一重大新闻事件专题报道中的特点和创新之处,以期为可预知事件网络新闻专题报道提供去同质化策略。 展开更多
关键词 可预知性 网络新闻专题 去同质化 策略
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Web对象可预取性研究 被引量:2
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作者 宋冰 石磊 古志民 《计算机工程与设计》 CSCD 北大核心 2006年第11期1964-1966,共3页
目前的Web预取模型一般是基于预测算法来提前取得Web对象,缺乏对Web对象可预取性的研究。若在预取Web对象之前考虑该对象的可预取性,将减少不必要的预取,不仅可以提高预取算法的命中率,也可以减少网络流量和系统负载。详细讨论了Web对... 目前的Web预取模型一般是基于预测算法来提前取得Web对象,缺乏对Web对象可预取性的研究。若在预取Web对象之前考虑该对象的可预取性,将减少不必要的预取,不仅可以提高预取算法的命中率,也可以减少网络流量和系统负载。详细讨论了Web对象的可预取性概念及相应的度量方法,并推导出在预取缓存交互的情况下,基于网络资源和系统负载计算预取阈值的公式,可用于Web对象的可预取性判断,指导预取控制,使得预取技术更加有效。 展开更多
关键词 WEB 可预取性 取控制 可缓存性
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基于加线技术的轨道交通临客开行计划优化模型
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作者 姚向明 程逸园 +2 位作者 张皓翔 邹庆茹 刘楠 《武汉理工大学学报(交通科学与工程版)》 2024年第3期409-414,共6页
基于运行图加线技术构建适于计划性临客开行的运行线铺画方法.以运力与客流匹配度最大化、对原运行图调整最小化为优化目标,考虑行车安全、临客加线位置、开行时间域等约束,构建临客运行线铺画非线性整数规划模型,并对其线性转换以提高... 基于运行图加线技术构建适于计划性临客开行的运行线铺画方法.以运力与客流匹配度最大化、对原运行图调整最小化为优化目标,考虑行车安全、临客加线位置、开行时间域等约束,构建临客运行线铺画非线性整数规划模型,并对其线性转换以提高求解效率.以北京地铁8号线某大型活动散场大客流为场景进行案例分析,结果表明:所构建方法能够在既有运行图上有效铺画临客运行线,满足不同行车密度及停站模式下的临客开行需求.建议在较高密度行车条件下不采用“空车直达”停站模式. 展开更多
关键词 临客列车 线性整数规划 城市轨道交通 运行图加线 可预知大客流
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可预涂微胶囊型厌氧胶的性能 被引量:7
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作者 杨颖泰 刘伟塘 《化学与粘合》 CAS 2001年第3期117-119,共3页
可预涂微胶囊型厌氧胶是汽车等工业生产线上使用的重要胶粘剂 ,本文对其相关的一些性能特别是GAY系列和GY - 5 6
关键词 微胶囊化 厌氧胶 性能 可预涂胶粘剂
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Antidepressant effects of Yuanzhi (Polygalae Radix) extract on chronic unpredictable mild stress-induced depression in rats: modulation of the NLRP3 inflammasome and NF-κB pathway
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作者 CHEN Yuzhen ZHAO Yongzhi +4 位作者 ZHANG Yiwen CHEN Fang Iqbal Choudhary Muhammad LIU Xinmin JIANG Ning 《Digital Chinese Medicine》 CAS CSCD 2024年第2期184-194,共11页
Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total ... Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways. 展开更多
关键词 DEPRESSION Yuanzhi(Polygalae Radix) Chronic unpredictable mild stress(CUMS) Proinflammatory cytokine Neuroinflammatory
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Future changes in precipitation and water availability over the Tibetan Plateau projected by CMIP6 models constrained by climate sensitivity 被引量:1
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作者 Hui Qiu Tianjun Zhou +3 位作者 Liwei Zou Jie Jiang Xiaolong Chen Shuai Hu 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第5期40-46,共7页
Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assesse... Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assessed likely range of equilibrium climate sensitivity(ECS)and the climatological precipitation performance,the authors constrain the CMIP6(phase 6 of the Coupled Model Intercomparison Project)model projection of summer precipitation and water availability over the TP.The best estimates of precipitation changes are 0.24,0.25,and 0.45 mm d^(−1)(5.9%,6.1%,and 11.2%)under the Shared Socioeconomic Pathway(SSP)scenarios of SSP1–2.6,SSP2–4.5,and SSP5–8.5 from 2050–2099 relative to 1965–2014,respectively.The corresponding constrained projections of water availability measured by precipitation minus evaporation(P–E)are 0.10,0.09,and 0.22 mm d^(−1)(5.7%,4.9%,and 13.2%),respectively.The increase of precipitation and P–E projected by the high-ECS models,whose ECS values are higher than the upper limit of the likely range,are about 1.7 times larger than those estimated by constrained projections.Spatially,there is a larger increase in precipitation and P–E over the eastern TP,while the western part shows a relatively weak difference in precipitation and a drier trend in P–E.The wetter TP projected by the high-ECS models resulted from both an approximately 1.2–1.4 times stronger hydrological sensitivity and additional warming of 0.6℃–1.2℃ under all three scenarios during 2050–2099.This study emphasizes that selecting climate models with climate sensitivity within the likely range is crucial to reducing the uncertainty in the projection of TP precipitation and water availability changes. 展开更多
关键词 Tibetan plateau Climate sensitivity Precipitation projection Water availability projection
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厌氧胶固化引发剂微胶囊的制备 被引量:11
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作者 龚永锋 傅相锴 +2 位作者 张树鹏 邹旷东 富丹 《精细化工》 EI CAS CSCD 北大核心 2006年第2期174-178,共5页
用原位聚合法制备了以厌氧胶固化引发剂过氧化羟基异丙苯为芯材、脲甲醛树脂为壁材的微胶囊。通过单因素比较法讨论了影响微胶囊制备的几个主要因素。实验表明,制备脲甲醛树脂微胶囊的最佳反应条件为:n(尿素)∶n(甲醛)=1.0∶2.0,壁材与... 用原位聚合法制备了以厌氧胶固化引发剂过氧化羟基异丙苯为芯材、脲甲醛树脂为壁材的微胶囊。通过单因素比较法讨论了影响微胶囊制备的几个主要因素。实验表明,制备脲甲醛树脂微胶囊的最佳反应条件为:n(尿素)∶n(甲醛)=1.0∶2.0,壁材与芯材的质量比为10∶3,阿拉伯树胶的质量分数为2.5%,乳化剪切速度为2 000 r/m in,加酸速度为40 m in内把pH降到1.5。实验制备的微胶囊分散性好、粒径分布窄、平均粒径约为100μm。 展开更多
关键词 可预 厌氧胶 微胶囊 原位聚合法 脲甲醛树脂
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Applications of nonferrous metal price volatility to prediction of China's stock market 被引量:2
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作者 彭叠峰 王建新 饶育蕾 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期597-604,共8页
The aim of the present work is to examine whether the price volatility of nonferrous metal futures can be used to predict the aggregate stock market returns in China. During a sample period from January of 2004 to Dec... The aim of the present work is to examine whether the price volatility of nonferrous metal futures can be used to predict the aggregate stock market returns in China. During a sample period from January of 2004 to December of 2011, empirical results show that the price volatility of basic nonferrous metals is a good predictor of value-weighted stock portfolio at various horizons in both in-sample and out-of-sample regressions. The predictive power of metal copper volatility is greater than that of aluminum. The results are robust to alternative measurements of variables and econometric approaches. After controlling several well-known macro pricing variables, the predictive power of copper volatility declines but remains statistically significant. Since the predictability exists only during our sample period, we conjecture that the stock market predictability by metal price volatility is partly driven by commodity financialization. 展开更多
关键词 commodity futures nonferrous metals price volatility stock return PREDICTABILITY
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APPLICATION OF MECHANICAL RELIABILITY PREDICATION BASED ON FUZZY THEORY 被引量:2
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作者 赵德孜 温卫东 段成美 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第1期76-80,共5页
Mechanical reliability prediction (MRP) is an important task of mechanical reliability design. In the initial design stage (IDS), the lack of reliability data and some fuzzy characteristics of MRP make this work hardn... Mechanical reliability prediction (MRP) is an important task of mechanical reliability design. In the initial design stage (IDS), the lack of reliability data and some fuzzy characteristics of MRP make this work hardness. Because fuzzy synthetical assessment (FSA) can well utilize expert′s experience and fuzzy data, it is used to assess the influence factors of reliability. On the basis of the assessed results, the predicted value of reliability is inferred by the fuzzy inference system (FIS). This approach particularly suits to predict the reliability of complex machinery (including other products) in IDS, so that it can remedy some defects of the existing methods. An example is discussed to interpret how to utilize it. 展开更多
关键词 mechanical reliability reliability prediction fuzzy synthetical assessment fuzzy inference
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Prediction of the Hualian Earthquakes in Taiwan and an Extended Discussion on the Method of Commensurability 被引量:4
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作者 胡辉 韩延本 《Applied Geophysics》 SCIE CSCD 2005年第3期194-196,F0003,共4页
The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 whic... The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 which occurred in the Hualian area of Taiwan within the 20th century, the authors discovered that the occurrences of the earthquakes are commensurable. The earthquakes of magnitude 7.6 which occurred in Hualian of Taiwan, on September 20th, 1999 and of magnitude 7.5 which occurred 70 km away from Hualian, on March 31th, 2002 appeared at the commensurable point of K=2 and the period times the golden section, respectively. An extended discussion is carried out on the method of commensurability and its implied physical significance, especially on the contribution of the commensurable periodic extension made by Prof. Weng Wenbo. 展开更多
关键词 information determinacy COMMENSURABILITY and extension of periodicity
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矿井“四可”安全管理模式
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作者 苗忠旺 《山东煤炭科技》 2012年第5期210-210,212,共2页
该文介绍了创新矿井安全管理体系,实施"可预、可防、可控、可靠"的"四可"安全管理模式,加大矿井安全防控力度,全力打造本质安全型矿井,具有推广价值。
关键词 安全管理 可预 可防 可控 可靠
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实施四可安全管理 构建安全生产新格局
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作者 闫明晨 《山东煤炭科技》 2013年第6期167-169,共3页
华丰煤矿以创建本质安全型矿井为主线,实施"可预、可防、可控、可靠""四可"安全管理模式,完善安全生产灾害事故监测、预警、预报体系,形成横到边、纵到底的全覆盖安全管理体系,提升全员安全意识,加大矿井安全防控力... 华丰煤矿以创建本质安全型矿井为主线,实施"可预、可防、可控、可靠""四可"安全管理模式,完善安全生产灾害事故监测、预警、预报体系,形成横到边、纵到底的全覆盖安全管理体系,提升全员安全意识,加大矿井安全防控力度,改善了矿井安全面貌。 展开更多
关键词 可预 可防 可控 可靠
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Design of Down Scalers in Mixed-Signal GHz Frequency Synthesizer 被引量:1
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作者 徐勇 王志功 +3 位作者 仇应华 李智群 胡庆生 闵锐 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第9期1711-1715,共5页
An optimized method is presented to design the down scalers in a GHz frequency synthesizer. The down scalers are comprised of dual modulus prescaler (DMP) and programmable & pulse swallow divider,different methods ... An optimized method is presented to design the down scalers in a GHz frequency synthesizer. The down scalers are comprised of dual modulus prescaler (DMP) and programmable & pulse swallow divider,different methods of high frequency analog circuit and digital logical synthesis are adopted respectively. Using a DMP high speed, lower jitter and lower power dissipation are obtained,and output frequency of 133.0MHz of the DMP working at divide-by-8 shows an RMS jitter less than 2ps. The flexibility and reusability of the progrs, mmable divider is high;its use could be extended to many complicated frequency synthesizers. By comparison,it is a better design on performance of high-frequency circuit and good design flexibility. 展开更多
关键词 PLL frequency synthesizer dual-modulus prescaler PROGRAMMABLE pulse swallow divider
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A Programmable 2.4GHz CMOS Multi-Modulus Frequency Divider 被引量:1
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作者 李志强 陈立强 +1 位作者 张健 张海英 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第2期224-228,共5页
A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 presc... A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China. 展开更多
关键词 PRESCALER frequency divider PROGRAMMABLE multi-modulus frequency synthesizer
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Estimation of Digestible Energy Values of Plant Protein Supplement in Pig 被引量:1
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作者 李明元 王康宁 《Agricultural Science & Technology》 CAS 2009年第2期97-101,107,共6页
[Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy (DE) values of plant protein supplement in pig. [Method] By difference method with different... [Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy (DE) values of plant protein supplement in pig. [Method] By difference method with different amount of alternative feeds (20% -50%), two4 x4 Latin- square-designed trials were taken on eight castrated male pigs [ Yorkshire x Landrace x Neijiang pig, initial body-weight: (46 ±2) kg ] to deter- mine the apparent digestible energy (ADE) of the eight kinds of plant protein supplement commonly used in China, that is, corn gluten meal (sol.), soybean meal ( sol. ), fababean, pea, rapeseed meal ( sol. ), sesame meal ( sol. ), rapeseed meal ( exp. ) and cotton seed meal (sol.). [Resultl (1) Fiber was the most important factor to estimate the ADE of plant protein supplement in pigs, and ADF was the best one. (2) The most effective equations were as below: ( 1 ) OE (kJ/kg DM) = 14 741.86 - 185.01ADF+54.01SCHO+22.45CP ( R =0.988,RSD= 67.9,P〈0.01 ) ; (2) DE (kJ/kg DM) =22 223.26 -209.58ADF+26.79SCHO-1.09GE ( Ff =0.989,RSD=66.9, P〈0.01 ) . [Conclusion] The accurate, practical and specific regression equations were established for DE prediction of plant protein supplement in pig. 展开更多
关键词 Plant protein supplement PIG Digestible energy ESTIMATION
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