论阎连科《日光流年》里的生与死     

乔媛 《科教文汇》2015,(2)

阎连科的《日光流年》讲述的是在耙耧山脉深处的几乎与外界隔绝的三姓村的故事。三姓村村民全都活不过四十岁,这也注定了死亡与生育生活生存的较量。历届村长带领村民与死亡斗争,充满北方人的对“生的坚强”和“死的挣扎”。三姓村村民的“生的坚强”表现在生育、生存和生活三个方面,而“死的挣扎”则表现在死亡的方式、意义和对棺材的重视三个方面。阎连科这种对死亡和生育的变态迷恋正是出于他对生命的热爱与绝望。  相似文献   

Characterization of chaotic multiscale features on the time series of melt index in industrial propylene polymerization system     

Ting Wang  Xinggao Liu  Zeyin Zhang 《Journal of The Franklin Institute》2014

The chaos characteristics of melt index have been first explored, and the Hilbert–Huang transform method and time delay embedding method are applied to multiscale dynamic analysis on the time series of the melt index (MI) in the propylene polymerization industry. The research results show that the embedding delay is 2, the embedding dimension is 5, the correlation dimension D₂ is 1.57, and the maximum Lyapunov exponent is 0.143 for the melt index series, which provide clear evidence of chaotic multiscale features in the propylene polymerization process. Three intrinsic mode functions (IMFs) are decomposed from the melt index time series; the presence of non-integer fractal correlation dimension and positive finite maximum Lyapunov exponent are found in some IMF components. The PP melt index series are divided into two chaotic signals, a determined signal and a random signal respectively, and its complexity is therefore reduced. Furthermore, the coupling of subscale structures of the propylene polymerization is explored with the dimension of interaction dynamics and a robust algorithm for detecting interdependence. It is found that IMF(2) is the main driver in the coupling system of IMF(1)and IMF(2). All these provide a guideline for studying propylene polymerization process with chaotic multiscale theory and may offer more candidate tools to model and control propylene polymerization system in the future.  相似文献   

无人机转角控制中的虚拟建模过程分析     

付媛媛 《科技通报》2014,(12)

无人机转角控制是无人机飞行中的关键。由于在对无人机进行操控时,存在一定的时间滞后性,利用传统的基于虚拟现实技术开发的无人机转角控制系统没有考虑时间的滞后性因素带来的影响,使得训练效果达不到实际操控无人机的要求,导致在实际操控中提高了无人机的坠机风险。为此,提出一种基于虚拟现实技术优化算法的无人机转角控制方法,建立无人机转角控制模型,得到转角控制参数,利用得到的时间误差进行补偿,得到新的无人机转角状态模型,利用新模型能够实现对无人机转角的精确控制。仿真实验结果表明,利用基于虚拟现实技术优化算法的无人机转角控制方法能够对无人机转角进行精确控制,效果令人满意。  相似文献   

中长跑运动训练对心脏收缩时间间期的影响     

张明军 《四川体育科学》2009,(2):35-37

采用MCA-3C心脏功能综合检测仪，观察男子中长跑运动员在功率自行车上进行递增负荷运动时心脏收缩时间间期各指标的变化，并与非运动员进行比较，从而对中长跑运动员的左心功能进行系统评价。结果发现：安静及递增负荷运动过程中中长跑运动员LVET和PEP相对较长；递增负荷运动过程中，中长跑运动员心脏功能表现出优于普通大学生的心脏功能水平。  相似文献   

On robust stabilization of uncertain stochastic time-delay systems—an LMI-based approach     

Chien-Yu Lu  Te-Jen Su 《Journal of The Franklin Institute》2005,342(5):473-487

In this paper, we first deal with the robust stability of uncertain linear stochastic differential delay systems. The parameter uncertainties are time-varying and unknown but are norm-bounded via two types of uncertainties, and the delays are time invariant. We then extend the proposed theory to discuss the robust stabilization of uncertain stochastic differential delay systems. These results are given in terms of linear matrix inequalities. Two examples are presented to illustrate the effectiveness.  相似文献   

Academic delay of gratification and children's study time allocation as a function of proximity to consequential academic goals     

Lili Zhang  Stuart A. KarabenickShun'ichi Maruno  Fani Lauermann 《Learning and Instruction》2011,21(1):77-94

Students (N = 302) in Chinese elementary schools were assessed regarding their academic delay of gratification (ADOG) and reported the time they devoted to non-school study and playtime during an extended interval prior to taking a high-stakes final exam. Students high compared those low in ADOG were more likely to spend time studying and less time playing several weeks prior to the exam. Growth curve analyses verified, however, that this difference diminished as a function of the temporal proximity to the exam, and that the group differences were non-existent just before the exam. Associations between ADOG and students' academic motivation and use of learning strategies replicated those obtained previously with adults in the USA. Results contribute to the general literatures on volition, homework and the dynamics of conflicting goals and action tendencies.  相似文献   

Predicting citation counts based on deep neural network learning techniques     

《Journal of Informetrics》2019,13(2):485-499

With the growing number of published scientific papers world-wide, the need to evaluation and quality assessment methods for research papers is increasing. Scientific fields such as scientometrics, informetrics, and bibliometrics establish quantified analysis methods and measurements for evaluating scientific papers. In this area, an important problem is to predict the future influence of a published paper. Particularly, early discrimination between influential papers and insignificant papers may find important applications. In this regard, one of the most important metrics is the number of citations to the paper, since this metric is widely utilized in the evaluation of scientific publications and moreover, it serves as the basis for many other metrics such as h-index. In this paper, we propose a novel method for predicting long-term citations of a paper based on the number of its citations in the first few years after publication. In order to train a citation count prediction model, we employed artificial neural network which is a powerful machine learning tool with recently growing applications in many domains including image and text processing. The empirical experiments show that our proposed method outperforms state-of-the-art methods with respect to the prediction accuracy in both yearly and total prediction of the number of citations.  相似文献   

职业体育俱乐部的企业社会责任对消费者的长期影响     

张森  王家宏 《北京体育大学学报》2018,41(10):19-24+31

摘要：以探讨职业体育俱乐部的企业社会责任如何长期影响消费者为研究目的,在2015~2016赛季的开始和结束阶段,分别选取职业体育俱乐部的消费者群体作为研究对象,采用定量问卷调查和定性内容分析相结合的研究方法,探讨我国职业体育俱乐部所履行的企业社会责任对消费者的长期影响。研究结果得出：在一个完整的商业周期内,职业体育俱乐部的企业社会责任对消费者的影响力逐渐增强,职业体育俱乐部的企业社会责任与消费者承诺的关联、消费者对职业体育俱乐部的承诺和消费行为之间的关联、消费者对职业体育俱乐部的承诺和俱乐部绩效之间的关联会随着时间的推移而增强,而企业社会责任和消费者对俱乐部信任之间的关联没有随着时间的推移而改变,承诺和信任两个变量在连接企业社会责任与提高职业体育消费者相关绩效的关联中产生了重要的中介作用,消费者的企业社会责任感知能够对消费者的关联态度产生直接影响,进而影响消费者的关联行为。建议我国职业体育俱乐部从业人员利用所得出的研究结果,有针对性的制定与实施企业社会责任策略,并将消费者的企业社会责任期望与感知整合到本俱乐部的信息营销系统中去,以检测消费者的需要、期望与感知的持续变化。  相似文献   

国际大型体育赛事与中国国家形象的时代特征及发展机遇*     

韩凤月  宋宗佩 《广州体育学院学报》2018,(6):5-8

我国从近代开始参与国际大型体育赛事,到目前为止已经成为参与、举办国际大型体育赛事较多的国家。在不同的历史阶段,国际大型体育赛事提升国家形象表现出不同的时代特征。当前,一带一路国家战略的积极实施、中国特色大国外交战略的积极推广以及体育强国建设的全面推进,为国际大型体育赛事提升国家形象带来了崭新的发展机遇。  相似文献   

图书馆科学发展的三维度量     

陈蜀园 《图书馆工作与研究》2011,(4)

图书馆科学发展观围绕人与自然、人与人之间关系的平衡,深入贯彻以人为本的核心理念;其阐述的三维特征,即数量维(发展度)、质量维(协调度)、时间维(持续度),使图书馆的发展具备了可观控性和可测度,从根本上科学地表征了对图书馆发展的完满追求.  相似文献