中国建筑企业如何应对新形势的挑战

在分析当前新形势下中国建筑企业面临的机遇与挑战的基础上，提出了针对性的应对措施，深入探讨和研究了国企改革发展的途径和国企经营管理战略的实施问题。     

Puff activity after heat shock in two species of the Drosophila obscura group

When individuals of Drosophila guanche are submitted to heat shock, five new puffs are induced. These puffs usually do not appear during normal development. Comparing these results with those obtained in Drosophila subobscura, also belonging to the obscura group, differences between the induced puffing pattern of both species have been found.     

Strontium isotope evidence for landscape use by early hominins

Ranging and residence patterns among early hominins have been indirectly inferred from morphology, stone-tool sourcing, referential models and phylogenetic models. However, the highly uncertain nature of such reconstructions limits our understanding of early hominin ecology, biology, social structure and evolution. We investigated landscape use in Australopithecus africanus and Paranthropus robustus from the Sterkfontein and Swartkrans cave sites in South Africa using strontium isotope analysis, a method that can help to identify the geological substrate on which an animal lived during tooth mineralization. Here we show that a higher proportion of small hominins than large hominins had non-local strontium isotope compositions. Given the relatively high levels of sexual dimorphism in early hominins, the smaller teeth are likely to represent female individuals, thus indicating that females were more likely than males to disperse from their natal groups. This is similar to the dispersal pattern found in chimpanzees, bonobos and many human groups, but dissimilar from that of most gorillas and other primates. The small proportion of demonstrably non-local large hominin individuals could indicate that male australopiths had relatively small home ranges, or that they preferred dolomitic landscapes.     

The genome of the green anole lizard and a comparative analysis with birds and mammals

The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments. Among amniotes, genome sequences are available for mammals and birds, but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes. Also, A. carolinensis mobile elements are very young and diverse-more so than in any other sequenced amniote genome. The GC content of this lizard genome is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds. We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations.     

基于小波分解和支持向量机的ENSO预测试验

为了改善ENSO的预测效果,基于Nino综合区的海温距平时间序列,采用小波分解和最小二乘支持向量机结合的方法,引入多步递阶预测的思想,建立ENSO的预测模型.试验结果表明:基于小波分解和最小二乘支持向量机结合的多步预测方法,可以有效提高ENSO的预报精度.同时,该模型具有同时得到不同时效的预测结果,建模方便,计算效率高...     

应用激光反射仪研究溶液吸附及吸附动力学

介绍了一种测量溶液表面吸附量和吸附动力学的技术.通过实验,将激光光学反射仪应用于溶液吸附上,设备通过仪器校正和光学模型,可以计算不同吸附层厚度灵敏度的线性关系,应用该技术测定了非离子表面活性剂C12EO5和两种蛋白质BSA、LSZ溶液和壳聚糖溶液的吸附动力学,由实验数据可分析吸附解吸动力学、求得最大吸附量,吸附解吸动力学有在线、直观、灵敏等特点.     

热轧生产线的建模与分析

用扩展时间事件图与极大代数方法相结合对一类批量生产的制造系统建立了模型 ,并在加工时间和存储器数量固定的条件下 ,用这模型对系统生产周期进行了分析 ,从而得到了机器的最大利用率.