A RESEARCH ON THE BENTHIC ECOLOGY ENVIRONMENT, ANTARCTIC OCEAN: Ⅰ. MAXWELL BAY AND ADMIRALTY BAY

Analyzing the information on benthic organisms and geochemistry, obtained from the Chinese First Expedition on Antarctic Ocean and its succeeded works and comparing with that of other oceans, this paper shows that in the circumstances of the researched area benthic organisms are rich. However, the prodsperity of the organisms is limited below 5-10 cm of the profiles in which the environment is mainly dominated by sulfate reducing reaction. On the condition of low temperature in Antarctic Ocean, the solubility of carbonates is higher than that of other latitudes of oceans, but the concentration of calcium in overlying water and pore water of the benthic environment is not higher than that in other oceans, which results in the difficulty for the crustaceas and mollusks to obtain sufficient calcium carbonate to form their solid shell as well as to bring about the lower ratios of these animals both in abundance and biomass in the researched ocean. Futhermore, there is a positive relationship between the dis     

海洋寄语

海洋是国民经济持续发展的重要保障,党的十六大确立了全面建设小康社会的目标,明确指出最根本的是要坚持以经济建设为中心,不断解     

南极磷虾富氟异常的原因及机理

通过对南极磷虾(Euphausia superba)体内及其甲壳中氟含量变化特征的分析,对南极磷虾富氟异常的原因进行了研究.结合其他有关资料,本文还对南极磷虾富氟的来源及机制进行了探讨.研究结果表明:(1)南极磷虾甲壳对氟具有再吸收的功能和作用,其对氟的富集存在着与生命活动无失的机理.南极磷虾的甲壳作为对氟具有特殊吸附功能的无机介质是其富氟的重要原因;(2)氟的富集来自海水,且可能是以离子交换吸附的方式进行.这一作用主要是通过氟与钙、磷的结合而体现.     

基坑开挖对邻近隧道影响的耦合分析方法

为了更合理和快捷地评估基坑施工对邻近已建地铁隧道的影响,将隧道视为弹性的地下连续梁来分析隧道本身的受力和变形,推导了隧道与周围土体相互作用的有限元耦合平衡方程,并引入弹性半空间层状模型来分析基坑卸载对土体和隧道变形性能的影响,建立了层状地基中基坑开挖对邻近隧道影响的耦合分析方法;然后,将提出方法与两阶段方法进行了算例对比,并结合离心机试验结果和工程实测数据进行了验证。研究发现,与两阶段方法相比,耦合方法在能反映出非均质层状地基土体的应力和应变集中（或扩散）现象,不仅具有更好的计算精度,而且减少了计算参数的数量;提出方法的理论计算值与离心试验结果基本一致,与工程实测变形数据基本吻合,验证了方法的有效性;通过工程实际应用得出的一些有益结论,可为合理制定城市基坑施工对邻近隧道影响的保护措施提供一定的理论依据。