共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Louis-Marie Lalancette 《International Review of Hydrobiology》1987,72(2):205-223
The Comparative Productivity of Two Ponds in the Vicinity of Lake St-John, Québec In 1980 and 1981, the productivity of two ponds near Lake St. John were evaluated. One, the pond of Desbiens, did not communicate with Lake St. John and the other, the pond of St-Gédéon, was connected to the lake. The aim of this study was to evaluate the contribution that a pond could make to the increase in productivity of Lake St. John which is a reservoir. The pond of Desbiens is more productive than Lake St. John but two to three times less than the pond of St-Gédéon. The pond of Desbiens shows an advanced degree of eutrophication whereas the pond of St-Gédéon is similar to the northern lakes by its physico-chemistry, zooplankton, sediments and benthic fauna. If we want to create artificial ponds, for a better productivity of reservoirs, it is important that they be connected to each other. 相似文献
9.
M. Canevet 《ITBM-RBM News (RBM News)》2000,21(1):6
Le problème de l'archivage centralisé des images numériques du plateau d'imagerie médicale ne sera pas abordé dans cet article, bien que certains médias de stockage présentés ici soient actuellement utilisés dans certaines solutions de type PACS (Picture Archiving and Communication System). 相似文献
10.
By use of Laurell's method, the quantitative evolution of three antigenic components of chicken erythrocyte non-hemoglobin proteins has been followed during the course of development. One of the constituents has been characterized as the yellow component previously described and its evolution has been confirmed. The significance of these modifications is discussed. 相似文献
11.
12.
Carne Ponte 《Option/Bio》2009,20(418-419):17-18
13.
Ren le Cohu 《International Review of Hydrobiology》1976,61(6):789-798
The influence of nitrates (NH4NO3 KNO3 and Ca(NO3)2) on Diatom populations has been studied. These populations were isolated by enclosures with transparent walls, without bottom or lid, placed in an oligotrophic pond. The addition of NH4NO3 generally resulted in a decrease in the number of Diatoms and the disappearance of some species. The addition of KNO3 and Ca(NO3)2 was followed, during some periods, by a very important increase of Achnanthes minutissima, Fragilaria construens and Gomphonema parvulum. 相似文献
14.
15.
16.
17.
18.
19.
20.
Nucleolar cycle in Physarum polycephalum was studied using EDTA preferential stain for RNP. We have been able to establish the following.
- 1. 1. The nucleolar remnants that are observed during mitosis correspond to the fibrillar zones of the interphase nucleolus.
- 2. 2. In prometaphase and metaphase the nucleolar remnants lie peripherically around the chromosomal mass with which they are only superficially associated.
- 3. 3. Preribosomal granules appear 10–15 min after metaphase in the prenucleolar bodies.