阻滞钠通道抑制心脏中的螺旋波和时空混沌

本文以LuoRudy91模型为基础，数值研究通过阻滞钠通道来抑制心脏中的螺旋波和时空混沌。结果表明该方法能在短时间内有效抑制螺旋波和时空混沌，原因是：该控制方法有效地抑制了去极化过程和加速复极化过程，导致螺旋波和时空混沌被湮灭。对控制方法可行性也作了简单讨论。     

限制钾离子电流抑制心脏中螺旋波和时空混沌

钾离子电流对心肌细胞的复极化过程有着重要的影响,以LuoRudy91模型为基础研究了通过限制钾离子电流最大值来抑制心脏组织中的螺旋波和时空混沌。结果表明:限制钾离子总电流能有效抑制螺旋波和时空混沌;含时和不含时外行钾离子电流之一不被抑制将会增大抑制螺旋波和时空混沌难度。控制机制是:抑制钾离子总电流明显地延长心肌细胞的有效不应期,导致螺旋波和时空混沌不能维持而湮灭。     

用晶格Boltzmann方法研究激发介质中时空混沌的产生与控制

采用晶格Boltzmann方法,通过计算机数值模拟,研究激发介质中时空混沌的产生与控制。结果发现激发介质螺旋波的失稳属于多普勒失稳;螺旋波破碎成时空混沌前出现波头螺旋式运动;处于时空混沌态的系统各个位置具有相同的振幅谱;适当频率的正弦振荡信号可有效地控制时空混沌态。     

国家自然科学基金重点项目简介

项目批准号:10335010 项目名称:时空斑图和时空混沌系统的研究 项目主持人:胡岗教授(物理学系) 资助金额:80万元 执行时间:2004 01—2007 12 参加项目主要成员数:10人 合作单位数:3个 主要研究内容:本项目研究时空斑图和时空混沌的性质,转化,控制与同步以及可能的应用.时空斑图的研 究重点以螺旋波为对象,研究螺旋波的形成与发展,以及由于螺旋波破碎导致向时空混沌的转换.时空混沌 的研究重点分析由于同步和退同步化导致时空混沌维数变化以及相关的分岔行为和普适性.时空斑图与时 空混沌的控制将研究利用局域共振驱动在时空混沌中…     

一种基于时空延迟反馈的时空混沌控制方法

研究耦合映象格子中的时空混沌控制问题。根据信号的自关联度与随机度之间的关系,提出了通过时空延迟反馈控制耦合单峰格子中时空混沌行为的方法,获得了很好的控制结果。这一控制方法不需要获取时空混沌系统中不稳定周期轨道的任何信息,控制参数的选择与被控的时空混沌系统的参数和方程无关。     

混沌信号驱动实现螺旋波和时空混沌抑制

首次提出采用Logistic映射的混沌信号抑制螺旋波．应用该方案对2个模型包括Fitzhugh—Nagumo和Panfilov系统进行了研究．数值计算结果表明：在无噪声下，微弱的混沌信号驱动可以很快控制系统到达均匀稳定态在时空噪声下，可以观测到螺旋波的破裂和丰富的斑图．该结果不同于噪声驱动下的螺旋波动态行为、     

螺旋波动力学研究新进展

讨论可激媒质中螺旋波的形成和其动力学行为、波头的运动和螺旋波失稳,介绍具有2个稳定点的双稳可激系统中时空斑图和其相应的理论,分析最近实验中发现的反螺旋波,给出螺旋波时空与混沌控制与同步的几种方案。认为螺旋波波头的运动反映了整个系统的对称性,在不同的参数范围内,可以观测到不同的斑图行为,对螺旋波动力学的深入研究有望解决诸如心脏失颤等实际问题,有望加强对非平衡热力学行为的进一步了解。     

阵发混沌和阵发同步:噪声在周期信号控制时空混沌中的作用及机制

当外加适当频率和强度的周期信号时,一维等离子体驱动耗散非线性漂移波方程中的时空混沌态能够被成功控制到空间有规的层流态;通过在驱动波坐标系中将系统变换成一组在周期势中运动的耦合振子(模式),模式之间的广义相同步被认为是控制的机制之一.本文的研究则发现,足够强的外加噪声可以使控制后空间有规的系统出现时空混沌的阵发;.在逐渐增大噪声强度时,层流态被越来越多阵发的时空混沌运动打断,直至最后都变成了无规运动;.而在时空混沌的阵发阶段,相位滑移导致模式之间的广义相同步也失去了.     

间歇线性反馈抑制螺旋波和时空混沌

采用间歇线性反馈的方法研究了一类激发介质中螺旋波和时空混沌的抑制问题．采用系统的采样变量与Logistic混沌信号来驱动系统．数值计算表明：选择恰当的采样周期，在非常小的反馈增益和无噪声下，大约50～80个时间单位后就可以消除Fitzhugh-Nagumo和Panfilov模型所对应的稳定旋转的螺旋波和时空混沌，系统达到稳定均匀态（0，0）．在时空噪声下，稳定旋转的螺旋波变得膨胀稀疏，可观测到螺旋波破裂和新的斑图．     

外加偏高斯噪声控制时空混沌

以一维驱动非线性漂移波方程为模型,通过对驱动波坐标系中扰动波能量和傅里叶模式相位进行模拟,研究了不同强度的外加偏高斯噪声信号对时空混沌进行非反馈控制的结果.研究发现,强度较小的偏高斯噪声不能将时空混沌成功控制,而较大强度的偏高斯噪声反而能够将时空混沌抑制到一种涨落较小的振荡运动.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

The Analects and the Moment in Peking——The influence of a Confucian education system on the personality formation,the way of thinking and the fate of the main characters

0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation＇s behavior in their social life throughout the long history is beyond list.