MULTIVARIATE CLASSIFICATION BASED ON METAL CONTENTS IN HUMAN SENILE CATARACT LENSES

Multivariate classification methods were used to evaluate data on the concentrations of eight metals in human senile lenses measured by atomic absorption spectrometry. Principal components analysis and hierarchical clustering separated senile cataract lenses, nuclei from cataract lenses, and normal lenses into three classes on the basis of the eight elements. Stepwise discriminant analysis was applied to give discriminant functions with five selected variables. Results provided by the linear learning machine method were also satisfactory; the k-nearest neighbour method was less useful.

Eu~(3+)离子在晶体KY_3F_(10)、YPO_4及YVO_4中的角重迭晶场参数计算

本文运用角重迭模型首次对Eu~(3+)离子在KY_3F_(10)S、YPO_4及YVO_4晶体中的四个角重迭参数e_σ、e_π、e_δ、e_φ进行了计算。结果表明,所得规律与文献[1]基本相符,并且e_σ和e_φ两个参数对能级的劈裂和移动也有着不可忽略的作用。

二甲基乙烯基乙氧基硅烷等离子体聚合

在外部电极电容耦合式辉光放电装置中进行了二甲基乙烯基乙氧基硅烷(VDMES)的等离子体聚合,考察了压力、功率以及基片距离对聚合速率的影响。用红外光谱和X射线光电子能谱(XPS)等方法研究了聚合物的结构,并研究了聚合物的热稳定性及表面性能。

高效液相色谱快速分离测定脂肪酸

本文介绍用高效液相色谱(HPLC)分析豆油中脂肪酸组成的方法。油脂经皂化后,不需萃取,直接形成脂肪酸的苯乙酮酯,通过梯度淋洗,使分离时间大大缩短。此方法可以直接应用到生物样品。

稀土三氟醋酸盐晶体的光谱特性

本文合成了系列稀土三氟醋酸盐晶体[Re(CF_3COO)_3·3H_2O](Re=Eu,Gd,Tb,Dy)和[Tb_xY_(1-x)(CF_3COO)_3·3H_2O]_2(x=0.05,0.10,0.15,0.20,0.25mol),测定其晶体结构属单斜晶系,空间群为P_(21/c);较详细地讨论了Eu~(3+),Gd~(3+),Tb~(3+),Dy~(3+)在这些化学计量化合物中的光谱特性,以及在[Tb_xY_(1-x)(CF_5COO)_3·3H_2O]中Tb~(3+)的发光强度随其浓度的变化规律。

Identification, Characterization, and Molecular Application of a Virulence-Associated Autotransporter from a Pathogenic Pseudomonas fluorescens Strain

A gene, pfa1, encoding an autotransporter was cloned from a pathogenic Pseudomonas fluorescens strain, TSS, isolated from diseased fish. The expression of pfa1 is enhanced during infection and is regulated by growth phase and growth conditions. Mutation of pfa1 significantly attenuates the overall bacterial virulence of TSS and impairs the abilities of TSS in biofilm production, interaction with host cells, modulation of host immune responses, and dissemination in host blood. The putative protein encoded by pfa1 is 1,242 amino acids in length and characterized by the presence of three functional domains that are typical for autotransporters. The passenger domain of PfaI contains a putative serine protease (Pap) that exhibits apparent proteolytic activity when expressed in and purified from Escherichia coli as a recombinant protein. Consistent with the important role played by PfaI in bacterial virulence, purified recombinant Pap has a profound cytotoxic effect on cultured fish cells. Enzymatic analysis showed that recombinant Pap is relatively heat stable and has an optimal temperature and pH of 50 degrees C and pH 8.0. The domains of PfaI that are essential to autotransporting activity were localized, and on the basis of this, a PfaI-based autodisplay system (named AT1) was engineered to facilitate the insertion and transport of heterologous proteins. When expressed in E. coli, AT1 was able to deliver an integrated Edwardsiella tarda immunogen (Et18) onto the surface of bacterial cells. Compared to purified recombinant Et18, Et18 displayed by E. coli via AT1 induced significantly enhanced immunoprotection.

山东半岛月湖潮汐汊道沉积物输运与堆积

月湖，又称天鹅湖，位于山东半岛最东端荣成湾顶的西南侧。面积约4.94 Km~2，西、北、南侧为陆地所包围，东部由荣成湾沙坝与外海隔开，东南部有一132m宽的潮流通道与外海相通，它由涨潮三角洲、落潮三角洲、纳潮盆地和潮汐通道四部分组成，是一个典型的潮汐汊道系统。1998年11～12月和1999年8～9月两次对月湖的沉积物特征，水动力条件，地貌特征做了广泛、深入的调查研。研究结果表明：月湖水深比较浅，大部分地区在1到1.5 m之间；底质呈环状分布，从湖边缘到中心依次为：砾质砂、泥质砂、砂质泥和泥，湖中心柱状样由粉砂或粘质粉砂组成，平均含水量为54.67％，平均有机碳含量为2.7％，测得沉积速率为1.49cm a~(-1)，沉积通量为1.04 g cm~(-2) a~(-1)有机碳通量为0.028 g cm~(-2) a~(-1)；月湖潮汐为不正规半日潮，日不等现象显著，口门主水道涨潮历时短，流速小，落潮历时长，流速大；口门主水道泥沙向外海搬输运，悬移质输运量比底移质输运量小近两个数量级；湖内沉积物粒径趋势分析表明沉积物由四周向湖心搬运。在过去的二十年里，由于人类对月湖的不合理开发和利用（在口门修建蓄水闸，虾池悬垦），造成泥沙大量淤积，使生态系统稳剧退化。如果不采取有效措施，月湖很快就会消失。

Classification of jinjiang oysters Crassostrea rivularis (Gould, 1861) from China, based on morphology and phylogenetic analysis

The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.

青藏高原地区根田鼠脾脏重量及迟发性超敏反应的季节性变化

动物的免疫功能不仅与外部环境条件有密切关系,而且可能在种群调节中有重要作用。为探讨青藏高原地区根田鼠免疫功能的季节性变化,我们在中国科学院海北高寒草甸生态系统定位站地区,从2006年5月至2007年4月,逐月捕获根田鼠,测定其脾脏重量及二硝基氟苯诱导的迟发性超敏反应。冷季1(2006年9～10月)个体的脾脏指数及迟发性超敏反应与暖季(2006年4～8月)个体之间无显著差异,但冷季2(2006年11月至2007年1月)和冷季3(2007月2～4月)个体脾脏指数、以及冷季3个体的迟发性超敏反应均显著低于冷季1和暖季个体,表明根田鼠免疫功能随冷季而显著降低。此外,冷季2不同年龄个体间的脾脏指数呈显著差异。我们认为,青藏高原冷季低温是影响根田鼠免疫功能季节性变化的主要因素,且冷季2不同年龄个体免疫功能的差异对根田鼠种群自动调节具有重要的作用。

国产赖草属（禾本科）两个类群的修订

根据标本研究、野外考察和实验观察，对国产赖草属Leymus两个类群进行了分类修订，将阿尔金山赖草Leymus arjinshanicus D．F．Cui和L．aerginshanicus D．F．Cui ssp．ruoqiangensis（S．L．Lu＆Y.H．Wu）D．F.Cui处理为若羌赖草L．ruoqiangensis S．L．Lu＆YH．Wu的新异名，将纤细赖草L．secalinus（Georgi）Tzvel．var．tenuis L．B．Cai提升为一个独立的种L．tenuis（L．B．Cai）L．B．Cai．

海北高寒草甸生态系统定位站辐射气候特征

以2000—03到2001—02的辐射观测资料，分析了海北高寒草甸生态系统定位站地区辐射及各分光辐射的变化特征．将为高寒草甸生态系统的物质循环、能量流动、草地生产力形成机制等问题的研究提供科学依据。结果表明：海北站区Eg、Er、UV、PAR、NIR和En具有明显的日、年变化，年内其总量分别达6278．867MJ／m^2、1515．139MJ／m^2、311．242MJ／m^2、2576．777MJ／m^2、3397．404MJ／m^2和2542．950MJ／m^2，其中在植物生长期的5—9月分别为3181．215MJ／m^2、698．021MJ／m^2、165．955MJ／m^2、1133．965MJ／m^2、1673．871MJ／m^2和1668．805MJ／m^2。年内Er、UV、PAR、NIR和Eh占Eg的比例分别为0．242、0．048、0．410、0．540和0．410，在植物生长期分别为0．219、0．052、0．413、0.528和0．527。对Eg和PAR提出了下列形式的模拟求算式．Eg=Eg0（0．089．7＋0．9768S／S0）和PAR=-3.8044＋0.4177％，模拟效果较好，可利用有关常规气象观测资料进行估算。

高原鼠兔间断性移动模式与反捕食对策分析

本文采用直接观测法,测定了高原鼠兔地面移动频率及每次移动距离.结果表明,高原鼠兔地面移动频率和每次移动距离依繁殖时期、年龄及性别而存在极显著的差异.繁殖早期,成年雄体地面活动频率大于成年雌体.繁殖后期,第1胎雄性幼体大于同年龄的雌体.繁殖早期,成年雌体地面活动频率高于繁殖后期,而幼体与成体之间无显著的差异.繁殖初期雄体每次移动距离大于雌体,其它时期雌、雄体之间则无明显的差别.雄体每次移动距离逐月降低.雌体每次移动距离无显著的季节性差异.研究结果进一步验证了暴露于风险环境中的植食性小哺乳动物,主要采取间断性移动模式,增加反捕食时间投入,降低风险的假设.

积雪对藏北高寒草甸CO2和水汽通量的影响

于2002和2003年冬季运用涡度相关法测定藏北草甸在有积雪和无雪条件下的CO2和水汽通量.结果表明:在同一层次CO2浓度,在有雪时CO2浓度低于无雪时,其中只有20 cm和160 cm层次间差异极显著(P＜0.01);在同一层次,前者的水汽浓度极显著地高于后者(P＜0.01);积雪时,CO2通量与5 cm土温相关不显著;高寒草甸CO2交换量,随着积雪时间的延长呈线性降低,而高寒灌丛和沼泽则相反;沼泽和草甸在有雪时,CO2通量值极显著高于无雪时(P＜0.01),而灌丛在这两个条件下CO2通量值之间差异不显著.