非传粉小蜂的食性及其对榕树- 传粉小蜂系统稳定性的影响

榕树与其传粉小蜂形成了高度专一的互惠共生系统。非传粉小蜂则是该系统的资源掠夺者, 但它与 该系统共存的机制仍不清楚。于2003 年12 月—2004 年4 月在西双版纳以聚果榕( Ficus racemosa L. ) 为材料, 研究了寄生在聚果榕榕果内的5 种非传粉小蜂的食性及相互关系, 以探讨非传粉小蜂与榕树- 传粉小蜂系统共 存的机制。结果表明: 寄生在聚果榕榕果内的5 种非传粉小蜂中, 仅Platyneura testacea Motschulsky 和Platyneu2 ra mayri Rasplus 能刺激子房发育成瘿花, 是造瘿者; Apocrypta sp . , Apocrypta westwoodi Grandi 和Platyneura a2 graensis Joseph 不能刺激子房发育成瘿花, 是拟寄生者。传粉小蜂的拟寄生者和造瘿者对传粉小蜂有负的影响, 但在蚂蚁和造瘿者的拟寄生蜂作用下, 这种负面影响并不显著, 而且它们对榕树繁殖没有显著影响。对小蜂自 然种群的分析表明, 传粉小蜂处于优势地位。说明在自然情况下传粉小蜂的拟寄生者和造瘿者的种群维持在一 个较低水平, 对榕树- 传粉小蜂系统稳定性影响较小, 故能与之长期共存。

从线粒体细胞色素b探讨长臀ba属三个种分类与进化的关系

细尾长臀ba与月斑长臀ba、长臀ba间存在遗传分化,分化程度与鲤科其它鱼类相似;而月斑长臀ba和长臀ba却无法分开。结果提示,月斑长臀ba和长臀ba很可能为同一个种。此外,长臀ba属与云南倒刺ba的亲缘关系较近,表明有争议的长臀ba属归入ba亚科是合理的。

Evidence of gene conversion in the evolutionary process of the codon 41/42 (-CTTT) mutation causing beta-thalassemia in southern China

The 4-bp deletion (-CTTT) at codon 41/42 (CD41/42) of the human beta-globin gene represents one of the most common beta-thalassemia mutations in East Asia and Southeast Asia, which is historically afflicted with endemic malaria, thus hypothetically evolvi

鱇(鱼良)白鱼线粒体DNA控制区结构和种群遗传多样性分析

用特异性引物对鱇(鱼良)白鱼(Anabarilius grahami)DNA进行PCR扩增,获得了鱇(鱼良)白鱼线粒体DNA控制区基冈全序列(930bp).控制区T、C、A和G碱基组成为29.8%、22.5%、33.0和14.7%.对照其他已报道的鱼类控制区结构,对鱇(鱼良)白鱼控制区结构进行了分析,识别了其终止序列区、中央保守区和保守序列区,找到了终止相关的序列TAS以及保守序列(CSB-F、CSB-D、CSB-1、CSB-2、CSB-3).同时运用DNA分析软件对鱇(鱼良)白鱼一个驯养种群(中国科学院昆明动物研究所珍稀鱼类繁育中心)及两个自然地理种群(江川县明星鱼洞、江川县牛摩村)进行了遗传多样性分析.结果显示:两个自然种群存在较强基因交流,未出现遗传分化;人工驯养种群遗传多样性最高,种群复壮程度较好.

Molecular phylogeny of the yuhinas (Sylviidae : Yuhina): a paraphyletic group of babblers including Zosterops and Philippine Stachyris

Mitochondrial sequences (2,379 bp) from cytochrome b, ND3, 12s and 16s rRNA were analyzed in order to reconstruct the phylogenetic relationships within the yuhinas (Yuhina), including the chestnut-faced babbler Stachyris whiteheadi which is endemic to the

墨江蜈蚣与少棘蜈蚣的比较研究. I.化学组成

对墨江蜈蚣(Scolopendra mojiangica) Zhang et Chi)与少棘蜈蚣(S. subspinipes mutilansL. Koch)的化学组成进行了比较分析。它们的蛋白质灼、烧残渣、水分含量基本相同。游离氨基酸挥发性脂肪酸和微量元素的相对含量也很接近, 但脂类和总糖的含量差异较大。

Effects of growth temperature of AlGaN buffer layer on the properties of A1(0.58)Ga(0.42)N epilayer by NH3-MBE

Al0.58Ga0.42N epilayers are grown by ammonia gas source molecular beam epitaxy (NH3-MBE) on (0001) sapphire substrate using AlGaN buffer layer. The effects of the buffer layer growth temperature on the properties of Al0.58Ga0.42N epilayer are especially investigated. In-situ high-energy electron diffraction (RHEED), double-crystal X-ray diffraction (DCXRD), atomic force microscopy (AFM), photoconductivity measurement and cathodoluminescence (CL) are used to characterize the samples. It is found that high growth temperature of AlGaN buffer layer would improve the crystalline quality, surface smoothness, optical quality and uniformity of the Al0.58Ga0.42N epilayer. The likely reason for such improvements is also suggested. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

1.3 mu m high indium content (42.5%) GaInNAs/GaAs quantum wells grown by molecular beam epitaxy

High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with 42.5% indium content were successfully grown by molecular beam epitaxy. The growth of well layers was monitored by reflection high-energy electron diffraction (RHEED). Room temperature photoluminescence (PL) peak intensity of the GaIn0.425NAs/GaAs (6 nm / 20 nm) 3QW is higher than, and the full width at half maximum (FWHM) is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality due to strain compensation effects by introducing N to the high indium content InGaAs epilayer. The measured (004) X-ray rocking curve shows clear satellite peaks and Pendellosung fringes, suggesting high film uniformity and smooth interfaces. The cross sectional TEM measurements further reveal that there are no structural defects in such high indium content QWs. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

42 MeV/u~(12)C与~(115)In反应的靶余核

本实验使用放射化学方法测定了42 MeV/u (12)C与~(115)In相互作用靶余核的生成截面。借助高斯电荷分布的假设得到了靶余核的质量分布。将实验得到的质量分布与熔合碎裂模型和级联的两体衰变模型进行了比较。特别值得注意的是，使用统计的两体衰变模型Monte Carlo GEMINI程序计算第一次与实验结果符合得非常满意。同时计算结果也表明：在42MeV/u的轰击能量下，完全熔合对靶余核的产物仍然有很大的贡献。在同样的假设下，得到了靶余核的同位素分布。可以看到，同位素分布的宽度随靶余核原子序数的增加而增加，在此对利用中能重离子反应生成新的远离β稳定线的缺中子核素进行了讨论