Cross-species chromosome painting in the golden mole and elephant-shrew: support for the mammalian clades Afrotheria and Afroinsectiphillia but not Afroinsectivora

Cross-species painting (fluorescence in situ hybridization) with 23 human (Homo sapiens (HSA)) chromosome-specific painting probes (HSA 1-22 and the X) was used to delimit regions of homology on the chromosomes of the golden mole (Ghrysochloris asiaticus) and elephant-shrew (Elephantulus rupestris). A cladistic interpretation of our data provides evidence of two unique associations, HSA 1/19p and 5/21/3, that support Afrotheria. The recognition of HSA 5/3/21 expands on the 3/21 synteny originally designated as an ancestral state for all eutherians. We have identified one adjacent segment combination (HSA2/8p/4) that is supportive of Afroinsectiphillia (aardvark, golden mole, elephant-shrew). Two segmental combinations (HSA 10q/17 and HSA 3/20) unite the aardvark and elephant-shrews as sister taxa. The finding that segmental syntenies in evolutionarily distant taxa can improve phylogenetic resolution suggests that they may be useful for testing sequence-based phylogenies of the early eutherian mammals. They may even suggest clades that sequence trees are not recovering with any consistency and thus encourage the search for additional rare genomic changes among afrotheres.

Indium mole fraction effect on the structural and optical properties of quaternary AlInGaN epilayers

AlInGaN quaternary epilayers with varying In mole fraction were investigated using triple-axis x-ray diffraction and photoluminescence measurements. The indium compositional fluctuation is enhanced with increasing In mole fraction, whereas the mosaicity of the AlInGaN epilayers is determined through the GaN template quality. Based on the analysis of the temperature dependence of the PL peak position, it is found that the localization effect strengthens with increasing In mole fraction due to the larger fluctuations of the In distribution. Increasing the influence of the localized state results in increasing the emission intensity and FWHM with the In content.

Effect of In-mole-fraction in InGaAs overgrowth layer on self-assembled InAs/GaAs quantum dots

We have studied the optical and structural properties of InAs/GaAs QDs covered by InxGa1-xAs (0 less than or equal to x less than or equal to 0.3) layer using transmission electron microscopy, photoluminescence (PL) spectra and atomic force microscopy. We find that the strain reduces in the growth direction of InAs islands covered by InGaAs instead of GaAs layer. Significant redshift of PL peak energy and narrowing of PL linewidth are observed for the InAs QDs covered by 3 nm thick InGaAs layer. In addition, atomic force microscopy measurements indicate that the InGaAs islands will nucleate on top of InAs quantum dots, when 3 nm In0.3Ga0.7As overgrowth layer is deposited. This result can well explain the PL intensify degradation and linewidth increment of quantum dots with a higher In-mole-fraction InGaAs layer. The energy gap change of InAs QDs covered by InGaAs may be explained in terms of reducing strain, suppressing compositional mixing and increasing island height. (C) 2000 Elsevier Science B.V. All rights reserved.

COMPARISON BETWEEN THE INFLUENCES OF LAYER THICKNESSES AND ALAS MOLE FRACTION-X ON VERTICAL-CAVITY SURFACE-EMITTING LASERS

Based on the n(x, lambda), the calculation of the reflection spectrum for vertical cavity surface emitting lasers shows that the deviation of the central wavelength caused by the change of layer thickness is much more than that caused by the change of AlAs mole fractions. Therefore the control of the MBE growth rate is very important.

Shock tube study of JP-10 ignition delay time

JP-10 (exo-tetrahydrodicyclopentadiene, C10H16) ignition delay times were measured in a preheated shock tube. The vapor pressures of the JP-10 were measured directly by using a high-precision vacuum gauge, to remedy the difficulty in determining the gaseous concentrations of heavy hydrocarbon fuel arising from the adsorption on the wall in shock tube experiments. The whole variation of pressure and emission of the OH or CH radicals were observed in the ignition process by a pressure transducer and a photomultiplier with a monochromator. The emission of the OH or CH radicals was used to identify the time to ignition. Experiments were performed over the pressure range of 151-556 kPa, temperature range of 1000-2100 K, fuel concentrations of 0.1%-0.55% mole fraction, and stoichiometric ratios of 0.25, 0.5, 1.0 and 2.0. The experimental results show that for the lower and higher temperature ranges, there are different dependency relationships of the ignition time on the temperature and the concentrations of JP-10 and oxygen.

BaF2替代BaO对钡镓锗酸盐玻璃光学性质的影响

在摩尔分数组成x(BaO),r(Ga2O),r(GeO2)为0．20，0．15,0．65的玻璃中，分别以摩尔分数0．05，0．10．0．15和0．20的BaF2替代BaO,研究了氟化物对玻璃折射率和光吸收性质的影响。结果表明，在玻璃中加入氟化物．玻璃折射率和色散降低，玻璃的紫外吸收边向短波侧迁移，而红外吸收边无明显变化。不含氟化物的氧化物玻璃中含有大量的OH基．这些OH基在2．24μm、2．97μm和4．23μm附近引起光吸收．在含氟化物的玻璃中，2．24μm的吸收峰消失，而2．97μm和4．23μm附近

含AlF3和ZrF4氟化物玻璃的分相与析晶

以摩尔组成为8．7MgF2-17．4CaF2-8．7SrF2-13．3BaF2-13．0YF3-31．6．AlF3-7．3ZrF4的氟化物玻璃为对象，研究了玻璃的分相和析晶．研究表明，玻璃中同时含有AlF3和ZrF4时，玻璃产生明显的分相，玻璃在高温下对水比较敏感，容易产生表面析晶．玻璃内部的析晶主要来自稳定性较差的富Al相，受空气中水分的影响，玻璃表面的析晶首先产生于富Zr相．依据玻璃的分相和析晶表现，讨论了含AlF3和ZrF4氟化物玻璃的表面析晶机理．

Yb^3＋掺杂锌锗碲酸盐玻璃的热分析、光谱和激光性质

设计了组成为0．70TeO2-(0．20-x)ZnO-xGeO2—0．05La2O3-0．025K2O-0．025Na2O-0．01Yb2O3(摩尔分数x=0,0．05，0．10，0．15和0．20)的碲酸盐激光玻璃，测试了热学性质、吸收光谱、荧光光谱和荧光寿命。计算了Yb^3+离子的吸收截面、受激发射截面、荧光有效线宽等参数。结果表明，组成为0．70TeO2-0．20GeO2-0．05La2O3-0．025K2O-0．025Na2O的玻璃具有优于著名的碲锌钠(TZN)玻璃的热稳定性，高的受激发射截面(1

TeO2-AlF3氟碲酸盐玻璃的性质和结构

制备了不同氟化物含量的（1-x）TeO2-AlF3（x=10％，20％，30％，按摩尔计）透明氟碲酸盐玻璃。利用差热分析和Raman光谱对玻璃的性质和结构进行研究。结果显示：当x达到30％时，氟化铝以Al-F多面体的形式进入玻璃网络结构。随着氟化物含量增加，玻璃在中红外区的透过率提高，玻璃结构单元从[Te（O，F）4]三方双锥向[Te（O，F）3]三方锥转变。Raman光谱显示：1个宽的强峰出现在750～840cm^-1，表明玻璃中Te-O键长介于0．185-0．196nm之间。

不同氧磷比对磷酸盐包边玻璃性质的影响规律

包边技术是提高大尺寸激光玻璃饱和增益系数的关键技术。采用传统的方法熔制玻璃,研究了 P2O5含量对 P2O5-Al2O3-B2O3-CuCl-Na2O-ZnO磷酸盐包边玻璃的折射率、热膨胀系数、玻璃转变温度、膨胀软化温度以及化学稳定性的影响。结果表明：当 P2O5的摩尔分数为 60%左右,玻璃样品具有最高的折射率（1.522 0）、最低的玻璃转变温度（352.4 ℃）、较好的化学稳定性[0.52 mg/（cm^2·d）]和适宜的热膨胀系数（128.427×10^-7/℃）,是用作钕磷酸盐激光玻璃硬包边的理

CuO,CuCl对P2O5-ZnO-Na2O玻璃性质的影响

包边技术是提高大尺寸激光玻璃饱和增益系数的关键。为获得优质包边玻璃,以CuO和CuCl分别作为Cu2+的引入物质,采用传统的玻璃熔制方法,研究了Cu2+掺杂量和不同引入物质对P2O5-ZnO-Na2O体系玻璃形成区、析晶稳定性、物化性能以及吸收系数的影响。研究结果表明,CuO和CuCl都能增大P2O5-ZnO-Na2O体系的玻璃形成区、提高玻璃样品的析晶稳定性。玻璃样品的吸收系数随Cu2+掺杂浓度的增加而明显增大,当Cu2+掺杂摩尔分数达到6%时,样品在1053 nm处的吸收系数为59.46 cm-1,基

Spectroscopic properties of Nd3+-doped high silica glass prepared by sintering porous glass

A new kind of Nd3+, -doped high silica glass (SiO2 > 96% (mass fraction)) was obtained by sintering porous glass impregnated with Nd3+, ions. The absorption and luminescence properties of high silica glass doped with different Nd3+, concentrations were studied. The intensity parameters Omega(t) (t = 2, 4, 6), spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd3+ concentration in high silica glass was 0.27% (mole fraction) because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd3+ doped oxide glasses and commercial silicate glasses, the Nd3+-doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.

沉积温度对氧化钇稳定氧化锆薄膜残余应力的影响

采用自制掺摩尔分数12%的Y2O3的ZrO2混合颗粒料为原料,在不同的沉积温度下用电子束蒸发方法沉积氧化钇稳定氧化锆(YSZ)薄膜样品。利用ZYGOMarkⅢ-GPI数字波面干涉仪对氧化钇稳定氧化锆薄膜的残余应力进行了研究,讨论了沉积温度对残余应力的影响。实验结果表明:随沉积温度升高,氧化钇稳定氧化锆薄膜中残余应力状态由张应力变为压应力,且压应力值随着沉积温度升高而增大;用X射线衍射仪表征了不同沉积温度下氧化钇稳定氧化锆薄膜的微观结构,探讨了薄膜微观结构与其应力的对应关系,并对比了纯ZrO2薄膜表现出的应力状态。

Characterization and molecular cloning of dabocetin, a potent antiplatelet C-type lectin-like protein from Daboia russellii siamensis venom

A novel C-type lectin-like protein, dabocetin, was purified from Daboia russellii siamensis venom. On SDS-polyacrylamide gel electrophoresis, it showed a single band with an apparent molecular weight of 28 kDa and two distinct bands with the apparent mole

Evolution and biogeography of talpid moles from continental East Asia and the Japanese islands inferred from mitochondrial and nuclear gene sequences

We sequenced the cytochrome b gene from two little-studied mammal species from the highlands of Southwest China, the long-tailed mole Scaptonyx fusicaudus and the gracile shrew-like mole Uropsilus gracilis. This data was used to examine the phylogenetic r