Benthic primary production, respiration and remineralisation: in situ measurements in the soft-bottom Abra alba community of the western English Channel (North Brittany)     

Aline Mign  Dominique Davoult  Jean-Jacques Bourrand  Guy Boucher 《Journal of Sea Research》2005,53(4):223

In situ measurements of ammonium and carbon dioxide fluxes were performed using benthic chambers at the end of spring and the end of summer in two soft-bottom Abra alba communities of the western English Channel (North Brittany): the muddy sand community (5 m, about 10% of surface irradiance) and the fine-sand community (19 m, about 1% of surface irradiance). High rates of ammonium regeneration were measured in the two communities at the end of summer (296.03±40.07 and 201.7±62.74 μmolN m⁻² h⁻¹, respectively) as well as high respiration rates (2.60±0.94 and 2.23±0.59 mmolC m⁻² h⁻¹, respectively). Significant benthic gross primary production (up to 6.11 mmolC m⁻² h⁻¹) was measured in the muddy sand community but no benthic primary production was measured in the fine-sand community. It suggests that microphytobenthic production values used in simulations previously published for these two communities were overestimated while values of community respiration were underestimated. The study confirms that this benthic system is heterotrophic and strengthens the idea that an important pelagic-benthic coupling is required for the functioning in such coastal ecosystems.  相似文献   

相关技术在冰水界面测量中的应用     

崔华义  郭纪捷 《海洋技术学报》2004,23(1):35-37

文章介绍了海冰监测设备的工作模式、测量原理，利用信号的相关性进行冰水界面反射信号处理，提高了测量精度，最后给出了测量信号的波形及相关图形。  相似文献   

Evaluation of Stress Intensity Factors Subjected to Arbitrarily Distributed Tractions on Crack Surfaces     

刘钧玉  林皋 《中国海洋工程》2007,21(2):293-303

The stress intensity factors (SIF) considering arbitrarily distributed surface tractions are evaluated based on the scaled boundary finite element method (SBFEM). The semi-analytical solving process for the stress intensity factors including the effects of surface tractions is presented. Provided are the numerical examples for the evaluation of mode Ⅰ and Ⅱ stress intensity factors with linear and non-linear distributing forces loaded on the crack surfaces. The crack problems of anisotropy and bimaterial interface are also studied and the stress intensity factors of single-edge-cracked orthotropic material and bi-material interface problems with surface tractions are calculated. Comparisons with the analytical solutions show that the proposed approach is effective and possesses high accuracy.  相似文献   

IEEE-488与非标准仪器接口连接     

冯天瑾  王荆  陈永生 《中国海洋大学学报(自然科学版)》1987,(2)

IEEE—488接口总线,是计算机与外部设备、仪器连接的通用标准并行接口,它要求被连接的仪器具有EEEE—488标准的接口。本文讨论,如何把它与非IEEE—488标准的仪器接口相连接。 首先,要研究非标准的仪器接口,找出它与IEEE—488标准的异同。必要时,应改焊此仪器的接口插头线端,使那些主要信号线功能与IEEE—488要求一致的线端处于与IEEE—488插口线端对应的位置,而功能不相容者不用。然后,试运行IEEE—488接口卡上EPROM中已有程序。必要时,应把三线联络方式改为西线、一线或零钱联络,并根据卡上I/O芯片功能自编连接子程序。这对所用IEEE—488接口卡的功能是一种扩充。 本文具体介绍了用此方法如何将TCH—瞬态仪与APPLEⅡIEEE—488接口卡连接,构成一个较强功能的高速瞬态信号采集与处理系统。  相似文献   

用RAM扩充程序存贮器     

王立红 《中国海洋大学学报(自然科学版)》1995,(Z1)

给出一种用ＲＡＭ扩充程序存贮器的方法，以及具体的硬件线路。这种简便实用的方法可为用户提供一种根据需要自行修改或编写应用程序的环境．  相似文献   

青岛地铁工程岩体风化规律探讨     

贾永刚  贾信远  方志海 《中国海洋大学学报(自然科学版)》1995,(3)

根据钻孔实测资料运用趋势面分析法研究青岛地铁沿线岩体风化规律，发现岩体各风化带界面标高及风化壳厚度呈波状起伏。指出：这主要受构造、岩性控制。岩体各风化带界面标高的变化与地表形态变化表现基本一致。  相似文献   

Friction Characteristics at the Pipe-Soil Interface     

Yan Shuwang Yan Chi Professor 《中国海洋工程》1994,(2)

-In order to analyze the stability of pipelines on the sea bed, the friction characteristics at the pipe-soil interface were examined by means of special direct shear tests. High density polythene was used as the surface of the pipe, which is a widely-utilized material for the outer cover of the pipe to prevent sea water corrosion. Sands of different gradings were tested. The reconstituted soft clay taken from the Bohai area was consolidated to different degrees of consolidation by the vacuum preloading technique, and tested.  相似文献   

Determination of Shear Interface Parameters between Rock Blocks for Centrifuge Modeling     

M. L. Talesnick 《Rock Mechanics and Rock Engineering》2007,40(4):405-418

  相似文献   

电渗法处理填土地基的排水效果影响因素分析     

李苗  张林洪  王苏达 《岩土工程技术》2007,21(1):4-6,10

以多雨潮湿地区回填土电渗室内试验现象和数据为依据,分析总结了影响电渗排水效果的因素,并针对工程实际应用提出了改进建议。  相似文献   

地球深部壳-幔边界的层束精细结构与物理属性研究   总被引：6，自引：1，他引：6  

滕吉文 《吉林大学学报(地球科学版)》2006,36(1):1-23

地球深部壳幔边界的介质结构和属性在地球内部圈层结构,特别是岩石圈结构与深层动力过程的研究中占有重要地位。这不仅由于它是地壳与上地幔的分界,而且它与深部物质的分异、调整及其深、浅物质的运移和耦合密切相关。研究结果表明:①通过地震宽角反射和近垂直反射波场效应可分辨其精细结构;②壳幔边界具有高低速相间的薄层、层束状多态结构;③来自壳幔边界复杂结构的地震反射波和宽角反射波具有明显的和各异的波场特征,并具有明显的动力学响应;④壳幔边界是一个主体由榴辉岩组构的化学界面;⑤给出了壳幔边界的广义模式。  相似文献