用正交设计优化甜菜RAPD反应体系

采用正交设计对甜菜的RAPD反应体系进行优化．应用L25（5^6）正交表,研究了Taq、Mg^2＋、随机引物、dNTPs和DNA模板5种RAPD反应组分浓度变化对扩增结果的影响,并进行量化分析,试验结果表明用这种方法建立的甜菜RAPD-PCR优化反应体系为：25μL反应体系中含1×Buffer、1．0mmol／L Mg^2＋、1U TaqDNA聚合酶、0．25mmol／L dNTPs、0．4μmol／L随机引物及25ng DNA模板．     

铝热法制备的ZrO_2/Al_2O_3复相陶瓷材料组织和力学性能

通过铝热反应制备ZrO2/Al2O3复相陶瓷材料,研究ZrO2含量对复相陶瓷显微组织与力学性能的影响.结果表明:复相陶瓷的相组成为ZrO2和Al2O3.随着ZrO2含量增加,ZrO2在基体中的分布越均匀,维氏硬度为8～15GPa,在ZrO2质量分数为41.5%时呈现最大值为14.85GPa;断裂韧性先增加后降低,在ZrO2质量分数为30%时呈现最大值8.01MPa.m1/2.     

Web环境下藏文信息处理技术

文章就浏览器中藏文字体显示的解决方案作了描述.它是建立在Microsoft提供的IE基础之上,利用IE 的ActiveX Control扩展特性以及Windows操作系统对True Type字体的底层基础设施,在应用层上实现了浏览器中藏文字体信息显示,并对现有技术的弊端加以阐释.     

藏医尿诊

藏医学作为一门独特的医疗体系 ,在诊断方面与众不同 尿诊就是一个既具独特又具有科学价值的诊断方法之一 所谓尿诊 ,就是医生通过观察患者的尿液来诊断疾病 尿诊的内容包括尿液的颜色、气味 ,蒸汽、气泡、尿液中的飘浮物和沉淀物等 藏医望诊中 ,尿诊最具特色     

Isotopic evidence for Late Cretaceous plume-ridge interaction at the Hawaiian hotspot

When a mantle plume interacts with a mid-ocean ridge, both are noticeably affected. The mid-ocean ridge can display anomalously shallow bathymetry, excess volcanism, thickened crust, asymmetric sea-floor spreading and a plume component in the composition of the ridge basalts. The hotspot-related volcanism can be drawn closer to the ridge, and its geochemical composition can also be affected. Here we present Sr-Nd-Pb isotopic analyses of samples from the next-to-oldest seamount in the Hawaiian hotspot track, the Detroit seamount at 51 degrees N, which show that, 81 Myr ago, the Hawaiian hotspot produced volcanism with an isotopic signature indistinguishable from mid-ocean ridge basalt. This composition is unprecedented in the known volcanism from the Hawaiian hotspot, but is consistent with the interpretation from plate reconstructions that the hotspot was located close to a mid-ocean ridge about 80 Myr ago. As the rising mantle plume encountered the hot, low-viscosity asthenosphere and hot, thin lithosphere near the spreading centre, it appears to have entrained enough of the isotopically depleted upper mantle to overwhelm the chemical characteristics of the plume itself. The Hawaiian hotspot thus joins the growing list of hotspots that have interacted with a rift early in their history.     

沼泽绿牛蛙的核型研究

本对沼泽绿牛蛙的染色体核型进行了研究。结果证明了沼泽绿牛蛙的核以式为Ｋ（２ｎ）＝２６＝１６ｍ＋１０ｓｍ有５对大型不染色体和８对小型染色体,可以分成Ａ、Ｂ、Ｃ组,雌雄性个体间没有性染色体的分化。在第７号染色体短臂上出现次缢痕。     

黄斑星天牛产卵刻槽的空间分布格局及抽样技术

黄斑星天牛是新疆伊犁部分地区杨树、柳树、榆树等树种的主要蛀干性害虫.通过判断空间分布型聚集度的5项指标,并利用Iwao M*-m回归分析法、Taylor幂法则对黄斑星天牛产卵刻槽的空间分布型和抽样技术进行了研究,研究结果表明黄斑星天牛的产卵刻槽在柳树上呈聚集分布,Iwao M*-m回归方程M*=5.24+1.03m(r=0.998 2),利用回归方程中的两个参数值α、β,计算在不同允许误差下(0.1,0.2,0.3)的抽样数公式N0.1=239 7.16/m+11.52,N0.2=599.29/m+2.88,N0.3=266.35/m+1.28,计算了黄斑星天牛产卵刻槽在不同密度下的最适抽样数,并制作了序贯抽样分析表,对在生产实践中根据人力、物力确定调查样本数、制定防治指标都有一定的借鉴意义.     

Visualizing heavy fermions emerging in a quantum critical Kondo lattice

In solids containing elements with f orbitals, the interaction between f-electron spins and those of itinerant electrons leads to the development of low-energy fermionic excitations with a heavy effective mass. These excitations are fundamental to the appearance of unconventional superconductivity and non-Fermi-liquid behaviour observed in actinide- and lanthanide-based compounds. Here we use spectroscopic mapping with the scanning tunnelling microscope to detect the emergence of heavy excitations with lowering of temperature in a prototypical family of cerium-based heavy-fermion compounds. We demonstrate the sensitivity of the tunnelling process to the composite nature of these heavy quasiparticles, which arises from quantum entanglement of itinerant conduction and f electrons. Scattering and interference of the composite quasiparticles is used to resolve their energy-momentum structure and to extract their mass enhancement, which develops with decreasing temperature. The lifetime of the emergent heavy quasiparticles reveals signatures of enhanced scattering and their spectral lineshape shows evidence of energy-temperature scaling. These findings demonstrate that proximity to a quantum critical point results in critical damping of the emergent heavy excitation of our Kondo lattice system.