东地中海沉积后氧化作用造成的腐泥的改造和清除

东地中海沉积后氧化作用造成的腐泥的改造和清除Ｎ．Ｃ．Ｈｉｇｇｓ等厚度大于１ｃｍ、有机碳含量大于２％的沉积层叫腐泥。大部分深水沉积中有机碳含量低，因此腐泥的形成需要特定的海洋地理条件。然而，在近４００ｋａ中，东地中海发育有至少１２层这样的腐泥，它们具有...     

北海地层水与成岩作用和生产化学的关系

1992年1月15日在英国伦敦地质协会举行了一个关于北海地层水：对成岩作用和生产化学的含义的会议．出席会议的代表有100多人．会议目的是把来自工业部门的技术人员和在工作中应用水化学信息的学术界的科学家聚集在一起．不同学科的相互结合取得令人满意的结果．     

地学发展与人才成长战略研讨会在京举行

地学发展与人才成长战略研讨会在京举行由中国地质学会主办的“地学发展与人才成长战略研讨会”于１９９７年１２月５—７日在北京西山宾馆举行。来自地矿部、国家教委、中科院、冶金部、化工部、有色金属总公司、核工业总公司、石油天然气总公司等部门５０多个单位、８４...     

Inhibition of P-glycoprotein transport: a mechanism for endocrine disruption in the channel catfish?

P-glycoprotein (pgp), an efflux transporter localized in a variety of tissues including the intestinal mucosa, renal tubules and bile canaliculi, is known to participate in the disposition of a variety of chemicals, including steroid hormones. This study examined the relationship of pgp to the movement into the bile of the hormone estradiol (E2), and the potential for transport interactions between the environmental pollutant nonylphenol ethoxylate (NPE) and E2. Biliary-cannulated in situ-prepared isolated perfused livers were used to assess pgp transport function. E2, in competitive transport preparations with Rhodamine 123 (Rho123), a pgp substrate, demonstrated significant decreases in Rho123 transport into bile, as did the prototypic inhibitor and substrate verapamil. [3H]E2 (0.28 nM) transport into bile was significantly reduced with either 20 M NPE or verapamil. These results suggest that E2 is a substrate and/or modulator for the catfish biliary pgp transporter, and that NPE potentially influences biliary transport and excretion of E2.     

Inhibition by polycyclic aromatic hydrocarbons of ATPase activities in Sebastiscus marmoratus larvae: relationship with the development of early life stages

Sebastiscus marmoratus larvae were exposed to waterborne polycyclic aromatic hydrocarbons (PAHs) containing 3-5 rings, benzo[a]pyrene (BaP), pyrene (Py) or phenanthrene (Phe), respectively at 0.01, 0.1 and 1 μg L?1. Cumulative mortality, frequency of dorsal curvature and rate of pericardial and yolk sac edema in larvae treated for 8 days were significantly increased in a dose-dependent manner. All three PAHs resulted in reduction of the lower jaw, and the extent of reduction increased with increasing concentrations of the PAHs. Na+/K+-ATPase and Ca2+-ATPase activity in larvae exposed to the three PAHs were all significantly inhibited in a dose-dependent manner. Analysis using the Pearson correlation coefficient indicated a significant correlation between the rate of the dorsal curvature and edema and the inhibition of Na+/K+-ATPase and Ca2+-ATPase activity, suggesting that the developmental defects caused by PAHs were related to their inhibition of Na+/K+-ATPase and Ca2+-ATPase activity.     

全新世早期以色列北部海岸沉积物扩散:地质与考古证据

最近在地中海东南面，以色列北部的阿特利特（Atlit）半岛外海约300m的内陆架水深8－12m处发现了较大的前史村落——阿特利特·亚姆（Atlit·Yam）。这个由面积超过60000m‘各种保存较好建筑物和寓所残痕组成的村落，依据丰富的各种各样的制造物，被认为建于前PotteryNeolithic晚期．考古勘测表明，村落经济较为复杂，包括通过农业、畜牧、打猎和捕鱼等获得各种食物来源．在阿特利特·亚姆，最惊人的发现是一口水井，水井顶部目前淹没在水深10m处。Galili和Nir（1993曾详细描述过这口水井，其直径为15m，深度为52m，其中大约3．8m为更新…     

Toxicity assessment of sediment cores from Santa Monica Bay,California

During the summer of 1997, sediment core samples were taken at 25 stations in Santa Monica Bay. Toxicity testing was performed on 4-cm sections of the entire length of each core using purple sea urchin fertilization and amphipod survival tests. The sea urchin test identified sections as being toxic at six stations, all located near current or former Hyperion Treatment Plant (HTP) wastewater outfall locations. The amphipod test identified sections from 17 stations as having toxic sediments. The stations having toxic sediments were scattered throughout the bay and toxicity was identified at numerous core depths. Spatial and temporal patterns indicated that toxicity was most strongly associated with the historical disposal of municipal wastewater sludge. Many of the sections toxic to the amphipods did not have chemical levels expected to cause toxicity and were in locations where a source of toxicity was not apparent.     

A Study of Lift Force and Instantaneous Velocity Field Around an Oscillating Circular Cylinder

-Force measurements of oscillatory flow acting on a single circular cylinder have been carriedout.The experiments were done by oscillating a circular cylinder in still water.Instantaneous forces and ve-locity fields around the cylinder were measured by Particle Image Velocimetry(PIV).The Keulegan-Car-penter number(KC)varied in the range from 5 to 20 and the viscous parameter β=Re/KC was set at500(Re is Reynolds number).It was found that the strength and frequency of the lift force increased withKC number,the main frequency of the lift force being three times the frequency of the oscillatory flow atKC=20.The movement and strength of the vortices around the cylinder are discussed for differentKC numbers.