甘草属（Glycyrrhiza L.)的系统学研究——兼论与假甘草属（Glycyrrhizopsis Bosis.&Bal.)的关系

甘草属（Glycyrrhiza L.）隶属于豆科山羊豆族甘草亚族，各大洲均有分布。本文对甘草属进行了全面的系统学研究，重点分析了各形态相关性状的变异式样及变异范围，首次发现甘草属的龙骨瓣不合生、分离，中国植物志四十二卷记载龙骨瓣合生，则有误;认为荚果形态和叶片性状是较为可靠的分种依据，小叶数目、花序疏、密以及小花大小等性状对于属下种类的划分也具有重要的分类学意义。首次在扫描电镜下观察了13种甘草属植物花粉粒的微形态特征，发现甘草属植物花粉为球形或近球形、三孔沟、萌发沟通常比较宽、沟边缘不整齐、沟膜较明显、表面通常具有疣状、瘤状或颗粒状突起;外壁纹饰以小孔穴状纹饰为主，还有皱纹状纹饰。花粉的形状、大小、外壁纹饰在种间存在变异，反映了一定的种间关系，对目前的属下分类系统提供了一些证据。对种子形态观察表明，该属植物的种皮表面纹饰特征比较相近，除圆果甘草(G. squamulosa)表面纹饰为圆丘状突起外，其余种类均以各种条纹状或回纹状突起为主。从种皮表面纹饰特征所反映的种间关系来看，有些与传统的分类结果一致，有些则不一致，无规律可寻，对于进行甘草属分类和种间系统演化关系研究不具有更高价值。对甘草属植物进行了分子系统学研究，测定5种甘草属植物的ITS序列，并从Genebank中下载21种的ITS序列，包括了2种甘草属植物及山羊豆族内其它10个属的代表。以紫藤为外类群，进行简约性分析，构建甘草属及其临近类群的系统发育树状图，结果显示，所研究的甘草属植物聚为一支，而山羊豆族内的其余类群在系统树上聚为另一支，表明甘草属与山羊豆族内其余类群的关系相对稍远;甘草属植物作为一个单系类群得到了100％的支持。在包括了山羊豆族、车轴草族、蚕豆族、鹰嘴豆族、岩黄芪族和灰叶族植物的系统发育树状图上，甘草属植物与山羊豆族的其余类群则处于不同的分枝上，进一步表明它们亲缘关系较远，包括甘草属的山羊豆族不是一个单系类群，甘草属的分类位置还需进一步研究。 作者在研究了4000余份腊叶标本及进行了大量野外考察的基础上，结合孢粉学、种子形态及分子生物学的证据，首次采用综合手段对世界甘草属植物进行全面的分类学修订。确认甘草属含3个组、13个种、1个变种，其中处理一新组合;对17个名称进行了归并;重新界定了广布种乌拉甘草（G.uralensis）和欧亚甘草（G.glabra）的变异范围，澄清了上述两种长期存在的名实混乱;考证了属的正确模式及一些种的合法学名，发现被命名为胀果甘草（G. inflata）的类群其正确名称应是G. paucifoliolata，建议将长期使用的胀果甘草作为保留名。确立假甘草属Glycyrrhizopsis Boiss. & bal.的独立地位，并确认该属具有2种1变种，处理新组合一个。本文对每一个种进行了详细的形态描述，并附分布资料及地理分布图，还给出了分组、分种检索表。

The toughness of adipose tissue: measurements and physical basis.

The measured toughness J(C) of adipose and dermal porcine tissues are 4.1 and 17 kJ m(-2), respectively, via a trouser tear test. An assessment is made of the contribution to overall toughness from the microstructural elements. The analysis suggests that the toughness of adipose tissue is determined by the collagen network that surrounds the adipocytes. The volume fraction of the interlobular septa is sufficiently low for it to make a negligible contribution to the macroscopic toughness.

Evolutionary status of Entamoeba

In addition to its medical importance as parasitic pathogen, Entamoeba has aroused people's interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eukaryotes, Entamoeba and several other amitochondrial protozoans have been recognized as ancient pre-mitochondriate eukaryotes and named "archezoa", the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acquisition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies revealed that Entamoeba contained an organelle, "crypton" or "mitosome", which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mitochondrion in Entamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status of Entamoeba is discussed.

Impact of heterogeneous link qualities and network connectivity on binary consensus

In this paper we consider a network that is trying to reach consensus over the occurrence of an event while communicating over Additive White Gaussian Noise (AWGN) channels. We characterize the impact of different link qualities and network connectivity on consensus performance by analyzing both the asymptotic and transient behaviors. More specifically, we derive a tight approximation for the second largest eigenvalue of the probability transition matrix. We furthermore characterize the dynamics of each individual node. © 2009 AACC.

中国神农架国家森林公园苔藓中的缓步动物

记述了采自湖北省西部神农架国家森林公园苔藓中的缓步动物12种,包括:日本棘影熊虫Echiniscus japonicus Morikawa,1951;双粒棘影熊虫Echiniscus bigranulatus Richters,1907中国新纪录种;华美假棘影熊虫Pseudechiniscus facettalis Petersen,1951;于猪假棘影熊虫Pseudechiniscus suillus(Ehrenberg,1853);迟缓小斑熊虫Milnesium tardigradum(Doyère,

长江上游主要河流鱼类多样性与流域特征关系

对长江上游12条主要河流鱼类种类数与流域特征进行了回归分析和主成分分析.相关回归分析结果显示:特有种类数目与全部种类数目呈极显著正相关;全部种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关,与比降呈显著负相关;单位流域面积(或单位干流长度)全部种类数与干流长度(或流域面积)、流量呈显著或极显著的负相关,与比降、径流深呈极显著正相关;特有种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关;单位流域面积特有种类数与干流长度、流量呈显著或极显著负相关,与比降、径流深呈极显著正相关;单位

中国美丽尖额溞(甲壳纲:双甲目)的新资料

<正> 美丽尖额溞(Alona pulchella King,1853)是广泛分布于澳大利亚区、埃塞俄比亚区以及新热带区的一种枝角类。据中国动物志淡水枝角类卷的记载,在我国只分布于广东、福建、北京、陕西及西藏,而且并不常见,雄性特征也不明。1989年6月中、下旬,在武汉市的中国科学院水生生物研究所一只曾用于培养本市东湖的水草而后閒弃室外的小水缸中,出现了美丽尖额溞的种群,而且有雌雄两性以及带卵鞍的个体,这在过去的文献中从未报道过。

Prediction and suppression of strong dispersive coupling in microracetrack channel drop filters

For a four-port microracetrack channel drop filter, unexpected transmission characteristics due to strong dispersive coupling are demonstrated by the light tunneling between the input-output waveguides and the resonator, where a large dropping transmission at off-resonance wavelengths is observed by finite-difference time-domain simulation. It causes a severe decline of the extinction ratio and finesse. An appropriate decrease of the coupling strength is found to suppress the dispersive coupling and greately increase the extinction ratio and finesse, a decreased coupling strength can be realized by the application of an asymmetrical coupling waveguide structure. In addition, the profile of the coupling dispersion in the transmission spectra can be predicted based on a coupled mode theory analysis of an equivalent system consisting of two coupling straight waveguides. The effects of structure parameters on the transmission spectra obtained by this method agree well with the numerical results. It is useful to avoid the strong dispersive coupling region in the filter design. (c) 2007 Optical Society of America.

Experiments and their analysis for self-assembly growth of GaN quantum dots via MOCVD

In recent years, growth of GaN-based materials-related quantum dots has become a hot topic in semiconductor materials research. Considerable efforts have been devoted to growth of self-assembled quantum dots of GaN-based materials via MOCVD (Metal Organic Chemical Vapor Deposition) and there are a lot of relevant literatures. There is, however, few review papers for the topic. In this paper, different experimental methods for fabrication of quantum dots of GaN-based materials via MOCVD are critically reviewed and the experimental conditions and parameters, which may affect growth of the quantum dots, are analyzed, with an aim at providing some critical reference for the related future experiment research.