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.     

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.     

一种提高视频车速检测精度的方法

通过对基于虚拟线的机动车视频测速方法的精度分析,提出了一种提高测速精度的方法.该方法在车道上定义一个矩形检测区,该检测区在视频图像上呈现出梯形,采用二维图像标定方法将梯形图像区域中任意一点的图像坐标准确地映射为检测区内对应点的地面坐标.通过在车辆经过检测区的视频图像中选取适当的图像帧,可以获得车辆的位移及对应的时间间隔,从而获得较高精度的速度测量结果.     

黑龙江鹿鸣钼矿床成矿岩体岩石地球化学特征

鹿鸣钼矿床产于燕山早期二长花岗岩-花岗斑岩岩体中,对其岩石学和地球化学特征进行分析.结果表明:SiO2质量分数在6384%~7132%之间,全碱质量分数为69%~84%,w(K2O)/w(Na2O)平均为137.岩体大部分属于偏铝-过铝质高钾钙碱性花岗岩.稀土元素总量值高,轻稀土富集,稀土分配模式为右倾曲线,同时Eu出现弱到中等程度的亏损.研究认为与成矿有关的二长花岗岩-花岗斑岩的岩浆属壳源岩浆演化形成的A2型花岗岩岩石组合,其形成背景应属于陆-陆碰撞之后的伸展体系.     

岩盐的蠕变损伤破坏分析

蠕变损伤破坏是岩盐的主要破坏形式之一，为此对长山岩盐和乔后岩盐进行了蠕变试验研究。通过对岩盐试件裂纹的产生、发展直至破坏过程的观察分析得出2种岩盐在蠕变损伤过程中有较大的差别。产生差别的原因主要是2种岩盐中NaCl的含量、晶粒大小、晶粒之间的胶结不同。造成2种岩样在蠕变过程中表现的现象不同，其岩盐力学性质也有差异。其次是岩盐在晶粒结晶过程中，因地质、环境等因素的影响，使晶粒内部存在着大量的缺陷，晶粒之间的交界面极不规则。因此，位措在这些晶体内占有重要地位，位措就控制了该晶粒的力学性质。