白洋淀重新蓄水后的轮虫     

阎书民  张军 《海洋湖沼通报》1991,(1):46-53

1989年对白洋淀重新蓄水后的轮虫作了采样调查,共采到轮虫123种,隶属于46属12科,并对鉴定到种的轮虫作了初步分析。  相似文献   

Seismic evidence of small-scale lacustrine drifts in Lake Baikal (Russia)     

Ceramicola  S.  Rebesco  M.  De Batist  M.  Khlystov  O. 《Marine Geophysical Researches》2001,22(5-6):445-464

High resolution, single-channel seismic sparker profiles across the Akademichesky Ridge, an intra-basin structural high in Lake Baikal (Russia), reveal the presence of small sediment mounds and intervening moats in the upper part of the sedimentary cover. Such features interrupt the generally uniform and even acoustic facies and are not consistent with the hemipelagic sedimentation, which is expected on such an isolated high and which would produce a uniform sediment drape over bottom irregularities. The influence of turbidity currents is excluded since the ridge is an isolated high elevated more than 600-1000 m above adjacent basins. The mounded seismic facies, including migrating sediment waves and non-depositional/erosional incisions, strongly suggest that sediment accumulation was controlled by bottom-current activity. We interpret the mounds as small-scale (< few tens of km² in area) lacustrine drifts. Four basic types of geometry are identified: 1) slope-plastered patch sheets; 2) patch drifts; 3) confined drifts; 4) fault-controlled drifts. The general asymmetry in the sedimentary cover of the ridge, showing thicker deposits on the NW flank, and the common location of patch drifts on the northeast side of small basement knolls indicate that deposition took preferentially place at the lee sides of obstacles in a current flowing northward or sub-parallel to the main contours. Deep-water circulation in the ridge area is not known in detail, but there are indications that relatively cold saline water masses are presently flowing out of the Central Basin and plunging into the deep parts of the North Basin across the ridge, a process that appears to be driven mainly by small differences in salinity. We infer that the process responsible for the observed bottom-current-controlled sedimentary features has to be sought in these large-scale water-mass movements and their past equivalents. The age of the onset of the bottom-current-controlled sedimentation, based on an average sedimentation rate of 4.0 cm/ky, is roughly estimated to be as least as old as 3.5 Ma, which is generally regarded as the age of the onset of the last major tectonic pulse of rift basin development in the Baikal region.  相似文献   

东太湖茭草区网围养鱼模式试验研究   总被引：5，自引：0，他引：5  

吴庆龙 《海洋湖沼通报》1997,(1):38-42

根据东太湖茭草区资源及环境特点,开展网围养鱼模式试验,结果表明：（1）经济效益明显,产投比1．2—1．5；（2）有良好生态效应,防治湖泊沼泽化和茭草区水质恶化；（3）社会效益显著,解决湖区剩余劳动力和城市居民吃鱼难的问题；（4）利于湖泊资源管理和保护。  相似文献   

石盐的³⁶Cl断代法     

黄麒 《海洋与湖沼》1992,23(5):492-497

讨论了~936)Cl的成因、~(36)Cl断代法的原理及测试方法。自1987年以来,应用该方法测得柴达木盆地尕斯库勒湖和大浪滩湖石盐的沉积年龄,并与~(14)C,~(230)Th和古地磁测年法所测得的年龄数据进行对比,结果均在误差(1δ)范围内相吻合,表明石盐的~(36)Cl断代法是可行的,获得的年龄数据是可靠的。  相似文献   

南沙群岛海域水体漫衰减系数Kd(490)的特性研究   总被引：6，自引：1，他引：6  

张清凌  陈楚群  施平 《热带海洋学报》2003,22(1):9-16

对南沙群岛海区水体Kd(490）的特性进行了深入分析和探讨,研究结果表明：Kd（490）的垂直分布与同步测量的海水叶绿素a浓度的垂直分布有很强的相关性;Kd（490）的垂直分布反映出该区域海水存在较强的分层现象,研究中还发现上行辐亮度漫衰减系数KL（490）与Kd（490）垂直变化趋势相当一致,但是以二者达到最大值的深度为界,上层水体的KL（490）值稍大于Kd(490）值,在这一深度以下则相反。  相似文献   

北方地区秋季日本对虾室内高密度精养的试验   总被引：2，自引：0，他引：2  

林琼武  单保党  刘立东  黄加祺 《台湾海峡》2001,20(4):510-514

为充分利用每年的8月以后直到翌年3月份都处于休闲状态的育苗场设施资源，笔者于1999年8月在河北黄骅进行日本对虾室内高密度精养的试验。在水温23－28℃、盐度28－32下，8月27日放苗，11月24日收成，养殖时间87d，单位水体产量平均为0．818kg/m^3，平均存活率为50．1％，旬生长率平均为0．75cm，成虾体长平均8cm，饵料系数为2．51，投入与产出比为2．5，平均单位水体创利63．83元／m^3，其结果说明本养殖模式不仅是可行的，而且具有利用率和效益高、实用性强的优点。本文还就相关问题进行了讨论。  相似文献   

Circulations east of Taiwan and in East China Sea and east of Ryukyu Islands during early summer 1985     

Yuan Yaochu  Cho-teng Liu  Pan Ziqin  Shi-pei Zheng 《海洋学报(英文版)》1996,15(4):423-435

Ｃｉｒｃｕｌａｔｉｏｎｓ　ｅａｓｔ　ｏｆ　Ｔａｉｗａｎ　ａｎｄ　ｉｎ　Ｅａｓｔ　Ｃｈｉｎａ　Ｓｅａ　ａｎｄ　ｅａｓｔ　ｏｆ　Ｒｙｕｋｙｕ　Ｉｓｌａｎｄｓ　ｄｕｒｉｎｇ　ｅａｒｌｙ　ｓｕｍｍｅｒ　１９８５ＹｕａｎＹａｏｃｈｕ；Ｃｈｏ－ｔｅｎｇＬｉｕ；Ｐ...  相似文献   

福建晚更新世海侵问题探讨   总被引：1，自引：0，他引：1  

曾从盛 《热带海洋学报》1993,(1)

福建沿海在晚更新世大约距今90—80ka、70—60ka、44—39ka和34—20ka期间分别发生过4次海侵。最末一次海侵(距今34—20Ka)期间有过明显的海面下降波动,时间大约在距今28ka前后。  相似文献   

Variation in the catchability of yellow perch (Perca flavescens) in the fisheries of Lake Erie using a Bayesian error-in-variable approach     

Jiao  Yan; Reid  Kevin; Nudds  Tom 《ICES Journal of Marine Science》2006,63(9):1695-1704

  相似文献   

Numerical study of the influence of Kuroshio Current on the thermocline in the sea area around Taiwan Island     

张文静  沙文钰 《海洋预报》2001,18(Z1):17-24

1 INTsoDUcrIONTemperature is one of the most impoFtant essential factors of ocean, and its verticalstructure, especially the phenomenon ofthermocline, is concerned by military and manufacturepractices at all times. There are two classes of research methods for thermocIine, statisticmethod and numerical method. In recent years, more attention has been paid to the latterwhich becomes the primary development direction. Since Munk et al (1948) pot forward1-D model of thermocline at steady sta…  相似文献