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81.
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83.
风力对内陆浅水水域磷水平的影响 总被引:1,自引:0,他引:1
本文通过对平度市大泽山水库(面积约0.5平方公里,平均水深约1.5米)的实地观测,研究了风力对内陆浅水水域磷水平的影响。结果表明,影响程度取决于风速、风力作用时间、水深以及风力作用前磷水平的高低等因素。就大泽山水库而言,风速大于2.5米/秒的风力可引起各种形态磷的明显增加。不过对磷酸盐磷来说,如果浓度本来就较高,风力作用下当有大量沉积物颗粒泛起时,会对PO_4~≡产生吸附,因而可能导致水中游离磷酸盐磷含量下降。鉴于此,作者建议对内陆浅水水域进行磷水平调查时应考虑风力的作用。 相似文献
84.
Comparison among four kinds of data of sea surface wind stress in the South China Sea 总被引:1,自引:0,他引:1
By using remote sensing (ERS) data, FSU data, COADS data and Hellerman & Rosen-stein objective analysis data to analyze the sea surface wind stress in the South China Sea, it is found that the remote sensing data have higher resolution and more reasonable values. Therefore we suggest that remote sensing data be chosen in the study of climatological features of sea surface wind stress and its seasonal variability in the South China Sea, especially in the study of small and middle scale eddies. 相似文献
85.
以棉粕蛋白为酶解底物,用枯草杆菌蛋白酶对其进行酶解,以酶解产物1.5%和3.0%两个梯度等量替代鱼饲料配方中棉粕,在室内流水养殖系统中喂养异育银鲫鱼种[体重为(30±2)g]65天。测定鱼的生长、营养物质表观消化率、消化蛋白酶活性及肝胰脏中胰蛋白酶mRNA表达水平等指标。结果表明,添加1.5%和3.0%棉粕酶解产物的鱼在饲养35天后的特定增长率(SGR)分别比对照组高32.5%和56.7%,且差异显著(P<0.05);在饲养65天后,两组特定增长率分别比对照组高8.0%和21.0%,且差异极显著(P<0.01),肝胰脏中胰蛋白酶mRNA表达水平也随棉粕酶解产物添加梯度提高而相应提高,表明鱼的生长与消化蛋白酶mRNA表达水平相关。同时棉粕蛋白酶解物对肠道蛋白酶的活性和营养物质表观消化率都有促进作用,而棉粕蛋白酶解物对鱼肌肉成分并没有改变,这也表明棉粕蛋白酶解物在促进鱼生长、内源酶活性同时并未降低鱼的品质。 相似文献
86.
The Spatial Distribution of Caprellidea (Crustacea: Amphipoda): A Stress Bioindicator in Ceuta (North Africa, Gibraltar Area) 总被引:4,自引:0,他引:4
Abstract. The caprellid (Crustacea: Amphipoda) community associated with the alga Cystoseira usneoides (L.) Roberts 1967 was studied on a spatial scale in relation to the influence of environmental factors on the coast of Ceuta (North Africa) using multivariate analyses. Twenty-two stations were sampled and five environmental factors were tested (hydrodynamics, silting, suspended organic matter, organic matter in silt and suspended solids). The spatial distribution of the caprellid community reflected the physico-chemical conditions of the coast. Phtisica marina Slabber 1769 was the only species present at the stations of the harbour of Ceuta, characterised by the lowest values of hydrodynamics and the highest values of silting, suspended organic matter and suspended solids. The most exposed stations (high hydrodynamics and low values of silting, dissolved organic matter and suspension solids) were mainly dominated by Caprella danilevskii Czerniavskii 1868 and C. penantis Leach 1814. These two species have developed a "parallel" posture that enables them to attach strongly to the substratum and thus inhabit areas subjected to heavy exposure or strong currents. Caprella acanthifera Leach 1814 and Pseudoprotella phasma (Montagu 1804) preferred stations characterised by moderate values of silting and suspended solids, such as those located in the coastal areas in front of the city of Ceuta, but these species were not found at the most stressed harbour stations. 相似文献
87.
将一个三维湍能封闭模型应用于开阔海区的风暴潮,通过数值计算探讨了Taylor底摩擦二次率的拖曳系数随空间的分布及拖曳系数与水深、海底粗糙度、风向和风速等因素的关系。本文对底摩擦二次率的可靠性做了评价。 相似文献
88.
本文通过对实测海平面高度的对比,发现龙口平均海平面从1991年起有明显的升高趋势。作者猜测此乃龙口在码头扩建后有系统下沉所致。 相似文献
89.
本文介绍了长江口区水文泥沙概况,举例说明了SSA1-1型声水位计在崇头潮位站比测试验和投产应用情况,结果表明该水位计是收集长江口区潮位资料较理想的仪器。 相似文献
90.
A New Methodology for Incorporating Tide Gauge Data in Sea Surface Topography Models 总被引:1,自引:0,他引:1
As part of the Vertical Offshore Reference Frames (VORF) project sponsored by the U. K. Hydrographic Office, a new model for Sea Surface Topography (SST) around the British Isles has been developed. For offshore areas (greater than 30 km from the coast), this model is largely derived from satellite altimetry. However, its accuracy and level of detail have been enhanced in coastal areas by the inclusion of not only the 60 PSMSL tide gauges with long-term records around the coasts of the United Kingdom and Ireland but also some 385 gauges established at different epochs and for different observation spans by the U. K. Admiralty. All tide gauge data were brought into a common reference frame by a combination of datum models and direct GPS observations, but a more significant challenge was to bring all short-term sea level observations to an unbiased value at a common epoch. This was achieved through developing a spatial-temporal correlation model for the variations in mean sea level around the British Isles, which in turn meant that gauges with long-term observation spans could be used as control points to improve the accuracy of Admiralty gauges. It is demonstrated that the latter can contribute point observations of mean sea level (MSL) with a precision of 0.078 m. A combination of least squares collocation and interpolation was developed to merge the coastal point and offshore gridded data sets, with particular algorithms having to be developed for different configurations of coastal topology. The resulting model of sea surface topography is shown to present a smooth transition from inshore coastal areas to offshore zones. Further benefits of the techniques developed include an enhanced methodology for detecting datum discontinuities at permanent tide gauges. 相似文献