External synchronization of two dynamical systems with uncertain parameters

External synchronization is addressed as two or more dynamical systems with synchronous motions, which is also regarded as master-slave system. In this paper, two dynamical systems, one employs a hysteretic term to model the friction phenomenon, the other involves a hardening stiffness component with the third order of displacement due to flexible deformation, are controlled to converge to the same trajectory. The control strategy is extended from feedback control for all parameters known to adaptive contro...     

TRIM24 links a non-canonical histone signature to breast cancer

Recognition of modified histone species by distinct structural domains within 'reader' proteins plays a critical role in the regulation of gene expression. Readers that simultaneously recognize histones with multiple marks allow transduction of complex chromatin modification patterns into specific biological outcomes. Here we report that chromatin regulator tripartite motif-containing 24 (TRIM24) functions in humans as a reader of dual histone marks by means of tandem plant homeodomain (PHD) and bromodomain (Bromo) regions. The three-dimensional structure of the PHD-Bromo region of TRIM24 revealed a single functional unit for combinatorial recognition of unmodified H3K4 (that is, histone H3 unmodified at lysine 4, H3K4me0) and acetylated H3K23 (histone H3 acetylated at lysine 23, H3K23ac) within the same histone tail. TRIM24 binds chromatin and oestrogen receptor to activate oestrogen-dependent genes associated with cellular proliferation and tumour development. Aberrant expression of TRIM24 negatively correlates with survival of breast cancer patients. The PHD-Bromo of TRIM24 provides a structural rationale for chromatin activation through a non-canonical histone signature, establishing a new route by which chromatin readers may influence cancer pathogenesis.     

用电化学法研究咪唑啉类缓蚀剂对碳钢的缓蚀性能

本文用线性极化，Tafel曲线，交流阻抗等电化学方法测定了三种咪唑类缓蚀剂在油田水中对碳钢的缓蚀性．找出缓蚀剂的最佳有效浓度，比较出这几种缓蚀剂之间的缓蚀效率大小，初步分析其缓蚀机理及其缓蚀效率差异的原因     

神经网络在储层横向预测中的应用

传统的冯·诺依曼程序存储式计算机擅长于数据处理，但是在类似于面貌及声音识别这样一些简单的认知问题方面，与人类相差很大．这种差异推动了神经网络的研究．本文讨论了误差反向传播网络（ＢＰ）．给出了ＢＰ网络在储层横向预测测方面的应用．     

武陵山地区蜘蛛群落多样性的研究

本文报道我国西南武陵山地区蜘蛛物种多样性和群落多样性的调查研究结果：取样区内已鉴定蜘蛛１９９种，隶属于９１属２９科，其中主要分布群为肖蛸、园蛛、狼蛛、球腹蛛、皿蛛、管巢蛛、漏斗蛛和跳蛛等科．依其植被和景观的不同，可将该区蜘蛛群落划分为８种类型，文中运用多种测度方法，着重分析了蜘蛛群落的垂直分层格局和水平分布格局的多样性特点及其与栖息地的关系．     

一个基于启发式分离向量搜索的凸多面体碰撞检测算法

碰撞检测是自然环境计算机模拟的基础,机器人等领域有着广泛的应用,本文提出了一个用于多面体碰撞检测的快速算法HS-jump,HP-jump算法建立了一个有效的检测模型,当两个凸多面体碰撞时,可以快速的报告它们之间碰撞, 当两个物体分离时,该算法提供了一个启发式搜索策略,用于快速的搜索分离物体的分离向量两个分离物体的分离平面的法 向量,与已有的算法相比,HS-jump算法可以更平衡的处理碰撞、分离的情况。     

计算机自动查重程序的算法分析

主要介绍了香港浸会大学图书馆于 2 0 0 1年自行开发计算机自动查重程序 ,以完全自动化方法 ,取代耗时费力的传统人工采访查重及馆藏评价的书目核对工序     

Forecasting the Nikkei spot index with fractional cointegration

We investigate the forecast performance of the fractionally integrated error correction model against several competing models for the prediction of the Nikkei stock average index. The competing models include the martingale model, the vector autoregressive model and the conventional error correction model. We consider models with and without conditional heteroscedasticity. For forecast horizons of over twenty days, the best forecasting performance is obtained for the model when fractional cointegration is combined with conditional heteroscedasticity. Our results reinforce the notion that cointegration and fractional cointegration are important for long‐horizon prediction. Copyright © 1999 John Wiley & Sons, Ltd.