基于免疫进化策略的神经网络优化方法

对神经网络的研究多年来主要集中于网络权值优化或结构优化上,却忽略了神经网络结构与权值之间密不可分的联系.针对上述问题,将免疫系统中的浓度机制和记忆机制引入进化策略,提出了一种基于免疫进化策略的神经进化算法,在优化网络拓扑结构的同时优化网络的连接权值.进一步地,用Cauchy变异算子代替传统的Gauss变异算子,以获得更为理想的全局收敛效果.理论分析和仿真结果表明,免疫进化策略能够很好地保持种群多样性,避免未成熟收敛,采用免疫进化策略设计神经网络具有良好的全局收敛性能和快速学习网络结构和网络权值的能力.     

浅析中国社会主义建设从“两位一体”到“五位一体”的转变

作为指导性文件,历届中国共产党全国大民代表大会的报告都备受瞩目。从“富裕中国”到“美丽中国”,笔者通过党的十二大以来党的纲领性报告中的不同阐述,试图总结社会发展的轨迹,进而分析其内在的发展动力,并通过文献研究、社会矛盾分析等研究方法,探讨了中国社会主义建设“两位一体”到“五位一体”的发展历程,提出了发展映射问题的观点。     

Ribonuclease 4, an evolutionarily highly conserved member of the superfamily

The structural and enzymatic properties of RNase 4 are reviewed. This RNase shows a much higher interspecies similarity (approximately 90%) than the other members of the RNase A superfamily. The enzyme is ubiquitous, with the highest amounts present in liver and lung. Its unique uridine specificity results from alterations in and around the pyrimidine-binding site. In particular, the shortened C-terminus and the side chains of Phe-42, Asp-80 and Arg-101 appear to be involved. RNase 4 binds tightly to the intracellular RNase inhibitor, with a K _d of 4 × 10⁻¹⁵ M.     

Cell wall polymers in Archaea (Archaebacteria)

The distribution of the various cell wall and cell envelope (S-layer) polymers among the main lineages of the domain Archaea (Archaebacteria) and the chemical composition and primary structure of polymers forming rigid cell wall sacculi is described. Differences between bacteria and archaea in their sensitivity to antibiotics which inhibit cell wall synthesis in bacteria are discussed.     

The angiogenins

The angiogenic and other biological functions of the angiogenins, members of the pancreatic RNase superfamily of proteins, are reviewed in the context of their primary and tertiary structures. The ribonucleolytic activity and interactions with the placental ribonuclease inhibitor have seen much study in the last few years. The mechanism of the angiogenic activity of angiogenin has recently been postulated as involving multiple interactions with other proteins through specific regions on the molecular surface of angiogenin. These molecular partners include heparin, plasminogen, elastase, angiostatin, actin and most importantly a 170-kilodalton receptor on subconfluent endothelial cells. The existence of the latter receptor was established in conjunction with a mitogenic activity of angiogenin on subconfluent cells. The levels of angiogenin in various physiological and disease states are summarized, including various studies on pregnancy and angiogenin. Correlations are seen between states of enhanced angiogenesis and angiogenin levels. An overview of the relationship of angiogenin and the other RNases of the superfamily showed that their genes all are in relative close proximity on human chromosome 14. Examination of the many expressed sequence tags published in the public databanks, for angiogenin and the other RNases, revealed that angiogenin and RNase-4 (the most evolutionarily conserved RNase), share various identical 5′-untranslated regions on their sets of messenger RNAs, suggesting that their genes are in very close proximity on chromosome 14 and that they are products of differential splicing. This in turn suggests that, in both humans and mice, expression of these two proteins is under identical control, with obvious implications for their biological activities. The evolutionary history of the angiogenins is examined briefly on the basis of the protein sequences of the human, rabbit, pig, two bovine and four mouse angiogenins, and two mouse angiogenin pseudogene sequences. The discrepancy between the conventional requirement for conservatism in structure to allow multimolecule interactions, and the actual fast-changing sequence of the angiogenins, in concert with the wide-ranging activity even in birds, of human angiogenin, is discussed.     

上古“向上看”概念场研究

＂向上看＂是指人把目光投向上方,在上古汉语中,人们用8个词项、三种结构模式来表达此义位。＂向上看＂概念场经过上古前期、上古中期、上古后期三个时期的历史演变,呈现出了各成员在发展过程中内部要素之间的消长和更替的情况。     

中国古代的矿物加工技术——传承与发展

介绍了中国古代的矿物加工技术，包括早期的石器和陶瓦制作，中国先民使用矿物制作器件，古代铁矿的矿冶加工利用，古代的湿法提铜，古代重选淘洗技术的使用和记述，古代的浮选技术，古代铜、铁矿冶生产规模等；也简要阐述了近现代中国选矿工业的兴起与科技发展，总结归纳了现代矿物加工科学技术的创新成就。     

社会经济学的发展与演变：基于思想史角度的考察

社会经济学是经济学的一个重要分支。通过对一些社会经济学家的经济思想的梳理，使我们认识到社会经济学的发展历程。在当代，注重整体性、和谐性、人本性的社会经济学越来越受到人们的重视，学科发展迅速，研究的主题也越来广泛深入，社会经济学具有广阔的发展前景。     

基于差异演化算法的化学方程式配平研究

根据质量守恒定律和化学方程式左右两边的原子构成建立数学模型,将化学方程式的配平问题转化为最优化求解问题.采用差异演化算法对其进行求解,给出基于差异演化算法的化学方程式配平的具体操作过程.通过对仿真实例的计算,结果表明差异演化算法能有效地确定出任意一化学方程式各物质前的最简系数,完成化学方程式的配平,为任意一化学方程式的配平问题提供了行之有效的方法.     

高校教师聘任制改革的历史沿革与实践困惑

建立和完善教师聘任制是建立现代大学制度的重要条件。中国高校教师聘任制度始于清末,1986年,中央正式决定改革过去的职称评审制度,实行专业技术职务聘任制。然而改革至今历时20余年,仍在艰难推行中。改革之艰难,根本原因在于高校自身无法解决的一些根本性问题,也就是外部环境不配套造成的。因此,只有具备良好的外部条件保障,聘任制才能长效运行并发挥应有的作用。