青藏高原的隆升与鰋鮡鱼类(鲇形目:鮡科)的隔离分化

系统发育和生物地理学分析认为喜马拉雅地区　　鱼类的物种分化过程与青 藏高原的隆升有直接的关系，并可用隔离分化假说加以解释．　鱼类的祖先与目前 广布的纹胸　属鱼类和／或　属鱼类相似．在Ｔｅｔｈｙｓ海封闭、印度板块与欧亚大陆碰撞 的初期，纹胸　属鱼类或经属鱼类广泛分布于青藏高原地区．更新世后，随着碰撞的 加深，青藏高原逐步隆起并造就了山区水系的急流环境，　　鱼类就是在这种环境因 子的压迫下从类纹胸　属鱼类产生的．目前跨喜马拉雅山分布的原　属就是　　鱼类 中最原始的种类．在青藏高原的３次隆升过程中，随着该区域水

人工四倍体鲤鲫的产生

在人工诱导的复合三倍体鲤鱼成熟个体中有极个别个体产出的卵既保留了原有的3套染色体,又能与一套外来精核融合产生四倍体。1997年人工产生的8000多尾鲤鲫四倍体鱼经细胞遗传学研究分析鉴定,结果所有的个体都有4套染色体组,染色体数目在185～210之间,众数为200,四倍体比率为100％。这表明人工复合三倍体鲤鱼的生殖方式十分独特,绝大部分个体的成熟卵可借助于外来精子的激动进行自然雌核发育;而有极个别个体的成熟卵能与外来精子融合产生四倍体个体。四倍体鲤鲫的形态特征像鲫鱼。

The effects of non-unity lewis numbers on turbulent premixed flame interactions in a twin V-flame configuration

The influence of Lewis number on turbulent premixed flame interactions is investigated using automatic feature extraction (AFE) applied to high-resolution flame simulation data. Premixed turbulent twin V-flames under identical turbulence conditions are simulated at global Lewis numbers of 0.4, 0.8, 1.0, and 1.2. Information on the position, frequency, and magnitude of the interactions is compared, and the sensitivity of the results to sample interval is discussed. It is found that both the frequency and magnitude of normal type interactions increases with decreasing Lewis number. Counternormal type interactions become more likely as the Lewis number increases. The variation in both the frequency and the magnitude of the interactions is found to be caused by large-scale changes in flame wrinkling resulting from differences in the thermo-diffusive stability of the flames. During flame interactions, thermo-diffusive effects are found to be insignificant due to the separation of time scales. © 2013 Copyright Taylor and Francis Group, LLC.

微囊藻毒素对鱼蛋白磷酸酶抑制作用的研究

国家自然科学基金39400024;淡水生态与生物技术国家重点实验室资助

鮊亚科类系统发育初探（鲤形目：鲤科）

Ｎ亚科鱼类系统发育初探（鲤形目：鲤科）乐佩琦，罗云林（中国科学院水生生物研究所，武汉４３００７２）关键词鲤形目，鮊亚科，系统发育ＰＲＥＬＩＭＩＮＡＲＹＳＴＵＤＩＥＳＯＮＰＨＹＬＯＧＥＮＹＯＦＳＵＢＦＡＭＩＬＹＣＵＬＴＲＩＮＡＥ（ＣＹＰＲＩＮＩＦＯＲＭ...

分子生态毒理学研究进展及其在水环境保护中的意义

分子生态毒理学研究进展及其在水环境保护中的意义徐立红，张甬元，陈宜瑜（中国科学院水生生物研究所，武汉４３００７２）关键词水环境，分子生态毒理学，水生动物，指标，早期报警ＴＨＥＡＤＶＡＮＣＥＳＯＦＭＯＬＥＣＵＬＡＲＥＣＯＴＯＸＩＣＯＬＯＧＹＡＮＤＩＴＳ...

世界豚类饲养设施的设计标准与白暨豚馆的设计

<正> 豚池是豚类动物饲养的基本条件,建设符合豚类动物生活,生长和繁殖所必需的饲养设施,是豚类饲养成败的关键之一。作者通过12年来白鱀豚Lipotes vexillifer饲养实践的总结,并实地考察了美、英、日、德国、法国、荷兰、瑞士和香港等国家和地区的豚类饲养设施,结合我国国情,设计了白暨豚饲养繁殖系统——新白鱀豚馆,为我国豚类养殖事业的发展打下了基础。

鱼类同工酶和蛋白质的聚丙烯酰胺梯度凝胶电泳法

<正> 同工酶分析一般常用淀粉凝胶电泳进行,但它常受淀粉质量的制约,在淀粉的水解和制胶过程较难标准化,因而不易掌握,其机械强度不够也不易操作。而聚丙烯酰胺凝胶电泳具有优于淀粉凝胶电泳的一些特性,如有较高的分辨率、机械强

Statistics of reaction progress variable and mixture fraction gradients from DNS of turbulent partially premixed flames

Statistically planar turbulent partially premixed flames for different initial intensities of decaying turbulence have been simulated for global equivalence ratios = 0.7 and 1.0 using three-dimensional, simplified chemistry-based direct numerical simulations (DNS). The simulation parameters are chosen such that the flames represent the thin reaction zones regime combustion. A random bimodal distribution of equivalence ratio is introduced in the unburned gas ahead of the flame to account for the mixture inhomogeneity. The results suggest that the probability density functions (PDFs) of the mixture fraction gradient magnitude |Δξ| (i.e., P(|Δξ|)) can be reasonably approximated using a log-normal distribution. However, this presumed PDF distribution captures only the qualitative nature of the PDF of the reaction progress variable gradient magnitude |Δc| (i.e., P(|Δc|)). It has been found that a bivariate log-normal distribution does not sufficiently capture the quantitative behavior of the joint PDF of |Δξ| and |Δc| (i.e., P(|Δξ|, |Δc|)), and the agreement with the DNS data has been found to be poor in certain regions of the flame brush, particularly toward the burned gas side of the flame brush. Moreover, the variables |Δξ| and |Δc| show appreciable correlation toward the burned gas side of the flame brush. These findings are corroborated further using a DNS data of a lifted jet flame to study the flame geometry dependence of these statistics. © 2013 Copyright Taylor and Francis Group, LLC.

第二固氮系统在蓝细菌红萍鱼腥藻中的发现

<正> 人们一般认为金属钼是生物固氮必需的条件,钼是固氮酶的主要催化活性的组成部分。早先一些学者曾研究以钒、锰代替钼的氮固定作用,到1980年美国的Bishop等人首先提出棕色固氮菌(Azotobacter vinelandii)具有不含铝的第二固氮系统。通过棕色固氮菌缺失编码固氮酶蛋白基因突变株研究发现,该菌株并不失去

白鱀豚生物学特征的初步研究

白鱀豚的体色较为单纯,背部青灰色,腹部为白色,但颈部及尾部有较为明显的斑纹。用牙齿作为鉴定年龄的材料,牙齿的外形和髓腔的大小可以判别属幼年、成年或老年豚。白鱀豚的成熟年龄,雄性为4龄以上,雌性为6龄以上,生殖交配期可能在4—5月份。白鱀豚在长江中游是以淡水经济鱼类为食。营集群生活,对流速有明显的选择性,群体巡游前进时,顺流游速为7.5—9.7公里/时,顶流游速为2.7—4.9公里/时。提出了白鱀豚年龄与体长的关系式及体重、体长和体围的相关式,可供有关研究工作者参考。

Characterisation of a high plasticity marine clay using a T-bar penetrometer

A series of laboratory-scale T-bar penetrometer tests have been conducted on a clay bed virgin consolidated from reconstituted high plasticity marine clay. This investigation was mainly concerned with the effects on the penetration resistance of rate of penetration and the presence of free water on the surface of the clay bed. The rate of penetration varied between 0.005mm/s and 50mm/s. The results showed that the nature of soil resistance was 'undrained' over the range of speeds studied, and the resistance showed a marked viscous rate effect. The virgin consolidated clay bed exhibited an increase in penetration resistance by up to 35% for a factor 10 increase in rate of penetration much larger than values previously reported for kaolin. The presence of water on the surface of clay bed had a profound impact on penetration resistance, particularly on the remoulded strength obtained by taking the T-bar through successive penetration and extraction cycles. This was true even when the remoulding cycles were conducted without the T-bar breaking through the clay surface.

大通湖的生物相及理化环境与近代沉积的初步报告

<正> 大通湖是原洞庭湖区中部经围垦而成的湖泊,跨湖南省南县和沅江两县,面积约185平方公里(28万亩)。湖水较浅,雨(夏)季平均深度2米左右,最大深度可达3.5米;枯水(冬)季节,水深在1.5米左右,最大深度仅为2米。湖东至西北湖岸,有数条小河流入,湖的南岸有两条小河道流出,湖中有由北而南的缓慢径流;南部水浅,水草丛生,北部较深,水草稀少。

Mode-locking by nanotubes of a raman laser based on a highly doped GeO2 fiber

A mode-locked Raman laser, using 25 m of a GeO2 doped fiber as the gain medium, is reported employing carbon nanotubes. The oscillator generates 850 ps chirped pulses, which are externally compressed to 185 ps. © OSA 2012.

How polluted is the Yangtze River? Water quality downstream from the Three Gorges Dam

The concentrations of major anions and cations, nitrogen and phosphorus, dissolved and particulate trace elements, and organic pollutants were determined for the middle and lower reaches of the Yangtze River (Changjiang) from below the Three Gorges Dam (TGD) to the mouth at Shanghai in November 2006. The concentration of dissolved inorganic phosphate (DIP) was constant at a low level of 6-8 mu gP/L, but the concentration of nitrate (NO3-) approximately doubled downstream and was closely correlated with K+. This translated to a daily load of well over 1000 It of dissolved inorganic nitrogen (DIN) at Datong. The average concentrations of dissolved Pb (0.078 +/- 0.023 mu g/L), Cd (0.024 +/- 0.009 mu g/L), Cr(0.57 +/- 0.09 mu g/L), Cu (1.9 +/- 0.7 mu g/L), and Ni (0.50 +/- 0.49 mu g/L) were comparable with those in other major world rivers, while As (3.3 +/- 1.3 mu g/L) and Zn (1.5 +/- 0.6 mu g/L) were higher by factors of 5.5 and 2.5, respectively. The trace element contents of suspended particles of As (31 +/- 28 mu g/g), Pb (83 +/- 34 mu g/g), and Ni (52 +/- 16 mu g/g) were close to maximum concentrations recommended for rivers by the European Community (EC). The average concentrations of Cd (2.6 +/- 1.6 mu g/g), Cr (185 +/- 102 mu g/g), Cu (115 +/- 106 mu g/g), and Zn (500 +/- 300 mu g/g) exceeded the EC standards by a factor of two, and Hg (4.4 +/- 4.7 mu g/g) by a factor of 4 to 5. Locally occurring peak concentrations exceed these values up to fourfold, among them the notorious elements As, Hg, and Tl. All dissolved and particulate trace element concentrations were higher than estimates made twenty years ago [Zhang, J., Geochemistry of trace metals from Chinese river/estuary systems: an overview. Estuar Coast Shelf Sci 1995; 41: 631-658.]. The enormous loads of anthropogenic pollutants disposed to the river were diluted by the large water discharge of the Yangtze even during the lowest flow resulting in the relatively low concentration levels of trace elements and organic pollutants observed. We estimated loads of e.g. As, Pb and Ni to the East China Sea to be about 4600 kg As d(-1), 3000 kg Pb d(-1), and 2000 kg Ni d(-1). About 6000 t d(-1) of dissolved organic carbon (DOC) was delivered into the sea at the time of our cruise. We tested for 236 organic pollutants, and only the most infamous were found to be barely above detection limits. We estimated that the load of chlorinated compounds, aromatic hydrocarbons, phenols, and PAHs were between 500 and 3500 kg d(-1). We also detected eight herbicides entering the estuary with loads of 5-350 kg d(-1). The pollutant load, even when at low concentrations, are considerable and pose an increasing threat to the health of the East China Sea ecosystem. (c) 2008 Elsevier B.V. All rights reserved.