一类奇摄动初值问题解的渐近展开

用边界函数法研究了一类奇摄动初值问题解的渐近展开问题,证明了解的存在惟一性,并给出该解的渐近分析.     

复杂规划问题的证据合成寻优方法及在电源规划中的应用

模拟人类寻优思维,将下降可行方向推广为证据合成网络,构造了证据合成算法和相应交互式寻优方法,并应用于电源规划问题     

Expansion of amino acid homo-sequences in proteins: Insights into the role of amino acid homo-polymers and of the protein context in aggregation

Expansion of amino acid homo-sequences, such as polyglutamines or polyalanines, in proteins has been directly implicated in various degenerative diseases through a mechanism of protein misfolding and aggregation. However, it is still unclear how the nature of the expansion and the protein context influence the tendency of a protein to aggregate. Here, we have addressed these questions using spinocerebellar ataxia type-3 (ATX3) protein, the best characterised of the polyglutamine proteins, chosen as a model system. Using a transfected mammalian cell line, we demonstrate that ATX3 aggregation is noticeably reduced by deletion or replacement of regions other than the polyglutamine tract. The nature of the amino acid homo-sequences also has a strong influence on aggregation. From our studies, we draw general conclusions on the effect of the protein architecture and of the amino acid homo-sequence on pathology. Received 3 March 2006; received after revision 19 April 2006; accepted 22 May 2006     

Huntington’s disease: from huntingtin function and dysfunction to therapeutic strategies

Huntington’s disease (HD) is a neurodegenerative disorder that usually starts in middle age and is characterized by involuntary movements (chorea), personality changes and dementia, leading to death within 10–20 years. The defective gene in HD contains a trinucleotide CAG repeat expansion within its coding region that expresses a polyglutamine repeat in the protein huntingtin. Together with the characteristic formation of aggregates in HD, aberrant protein interactions and several post-translational modifications affect huntingtin during disease progression and lead to the dysfunction and death of selective neurons in the brains of patients. The exact molecular mechanisms by which mutant huntingtin induces cell death are not completely understood but may involve the gain of new toxic functions and the loss of the beneficial properties of huntingtin. This review focuses on the cellular functions in which huntingtin is involved and how a better understanding of pathogenic pathways can lead to new therapeutic approaches. Received 24 May 2006; received after revision 5 July 2006; accepted 23 August 2006     

EVA塑料发泡倍率的影响规律实验

采用田口实验设计方法,选取模具温度、模压时间、注射压力和模压压力进行正交实验,分析工艺参数对EVA(乙烯-醋酸乙烯酯共聚物)发泡倍率的影响.结果表明,模具温度对发泡倍率的影响较为显著,模压时间次之,注射压力与模压压力的影响较小.随着模具温度的升高,发泡倍率逐渐增大,最终趋于稳定值,随着模压时间的增加,发泡倍率也逐渐最大...     

论政府规模扩张的三个缘由

现代政府规模总处在持续的扩张状态之中,其原因是复杂的。但从政府在社会中所发挥的作用看来,社会分工的发展、政府组织自身的行为,以及社会与公众对政府日益增长的公共产品与服务的需求在客观上刺激了政府规模的扩张。     

湍流燃烧的简化的联合PDF模拟

为同时满足工程应用中的合理性和经济性 ,提出了一种简化的联合三维高斯分布的 PDF模型 ,将其用于后台阶突扩燃烧室中甲烷燃烧的数值模拟。由于充分考虑了组分浓度、温度的一阶矩以及它们的二阶自关联矩和互关联矩对化学反应速率的影响 ,得到的火焰形状和温度分布无论是定性还是定量上都比 EBU模型和 Arrhenius模型合理。因计算量较小 ,模型在工程实际中 ,特别是污染物生成的数值模拟中得到应用     

利用霍尔元件测量空心铜管的线膨胀系数

膨胀系数用于表征固体材料的物理属性,具有广泛的科研和实践意义.为了减少物理量的测量个数、提高测量精度,根据霍尔元件在梯度磁场中的位移与霍尔电压的线性关系,提出了一种新的利用霍尔元件测量空心铜管线膨胀系数的实验方法.通过该方法测得一定温度范围内（20.6℃-70.6℃）空心铜管的线膨胀系数为1.6747×10-5/℃,与理论值1.67×10-5/℃相比,相对误差仅为0.27％,表明该测量方法具有较好的理论与实际应用价值.     

基于Projector的球罐表面测地线展开法

基于投影工具Projector,提出一种实用的球罐表面展开方法.过球罐表面上一系列测地线将罐体表面划分为小块,提取每一小块的曲面边界曲线作为输入项逐一进行计算、连线并自动生成展开图,最后再集拢到展开后的球罐外表面.与传统的方法相比,应用该方法对球罐表面进行展开可以保证焊缝的长度最短,且展开过程形象直观.故球罐的质量、安...     

Reversible audio watermarking algorithm using non-causal prediction

Reversible watermarking technique enables to extract embedded information without any loss of the host signal. For the reduction of the embedding distortion, a desirable reversible watermarking approach should exploit efficient prediction way to generate prediction errors with a smaller magnitude for expansion embedding. In this paper, we present a reversible audio watermarking scheme based on a new non-causal prediction method and embedding strategy. The proposed non-causal prediction method provides non-integer prediction errors and the proposed expansion embedding strategy can proceed them for a lower embedding distortion. Experimental results have shown that the proposed reversible technique has a lower embedding distortion for the same embedding payload in comparison with the existing state-of-the-art works.