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901.
长江口外高桥电厂码头区冲淤变化定量分析 总被引:4,自引:2,他引:4
岸滩稳定性及取排水口的水深状况是电厂水工建筑物布置决策的重要依据,本文通过遥感和地理信息系统软件的支持,在数字化地形图分层叠加的基础上,对外高桥码头区的淤积及发展趋势进行定量分析。 相似文献
902.
三都湾互花米草的遥感监测 总被引:8,自引:0,他引:8
本文尝试通过分析滩涂上外来入侵植物群落的植物学和生态学特征,就闽东宁德地区三都湾海域的互花米草生长与变化状况,探讨如何实现利用遥感数据快速监测滩涂上的外来入侵植物的方法,为生物入侵监控工作提供决策依据.研究表明以缨帽变换的方法处理LandsatETM 和TM多光谱数据所获得的土壤视面和植被视面为基础,进行分层次分类可监测滩涂上互花米草的生长与分布扩展状况. 相似文献
903.
运用半封闭港区水域泥沙回淤研究结果,以及电厂港池取水物理模型试验结果,提出电厂港池取水回淤计算模式。应用此模式对某港拟建电厂各取水工况进行港池航道回淤计算分析。 相似文献
904.
几种中草药对光合细菌生长的促进作用 总被引:1,自引:0,他引:1
提出在培养基中添加一定浓度的栝楼、木瓜、蒲公英和桔梗等中草药浸提液,可明显促进光合细菌的生长。其中,以栝楼的促生效果最好,浸提物浓度愈高,促生效果愈明显。所试浓度的栝楼、木瓜浸提液,没有发现对光合细菌生长有抑制作用。指出在生产性培养中,添加某些中草药促进光合细菌的生长是可行的。 相似文献
905.
A review of the biology and genetics of sea lice 总被引:5,自引:0,他引:5
906.
Daniela Prevedelli Gloria Massamba N'Siala Ivano Ansaloni & Roberto Simonini 《Marine Ecology》2007,28(3):384-393
The life cycle of a brackish water population of Marphysa sanguinea (Polychaeta Eunicidae), from the Venice Lagoon (Italy), was investigated from April 1993 to August 1994. Marphysa sanguinea is a large‐sized gonochoric species with annual iteroparous strategy and synchronous spawning at population level. The sex‐ratio was close to 1:1. There were no morphological differences between males and females and spawning occurred without epitokal metamorphosis. The gonadial activity was maximum during summer period in both sexes. From May to September in the females, the greater number of immature oocytes could be observed; starting from November immature oocytes decreased and progressively those with a wider diameter increased in number. Spawning took place in April–May and generally not all eggs were spawned, a small proportion being kept as a reserve material for the following gamete production. The pelagic phase (trochophore and metatrochophore stages) was short (2–3 days). The reduction in the dispersal phase, together with the development of a strong anterior musculature, brought to an early acquisition of the benthic habit, which was attained with the construction of the mucous tube inside of which the larva lived. The results highlighted that colonization of brackish environments took place thanks to morphological and physiological features that allow this species to live in a sediment layer characterized by the stability of the physical and chemical characteristics of the substratum. 相似文献
907.
Higher plant n-alkane average chain length as an indicator of petrogenic hydrocarbon contamination in marine sediments 总被引:1,自引:0,他引:1
The n-alkane average chain length (ACL) is the weight-averaged number of carbon atoms of the higher plant C25–C33 n-alkanes. The abundance of individual n-alkanes from higher plant sources generally increases with increasing carbon number in coastal marine sediments around Taiwan, but this trend is reversed for petrogenic hydrocarbons. The ACL would potentially be lowered if petrogenic hydrocarbons were added to sediments containing biogenic hydrocarbons alone. To test this idea, a marine environment off southwestern Taiwan known to contain both biogenic and petrogenic hydrocarbons and two nearby rivers were selected for investigating possible difference in ACL values between their sediments. The average CPI of C25–C33 n-alkanes was 4.08 ± 2.04 (range 1.90–8.96, n = 15) for the river sediments and 1.70 ± 0.16 (range 1.43–1.97, n = 15) for the marine sediments. The ACL of C25–C33 n-alkanes for river sediments ranged from 29.2 to 30.5 (average 29.9 ± 0.4), and for marine sediments from 28.4 to 29.3 (average 28.9 ± 0.3). The ACL difference between marine and river sediments was significant (Student's t test at 99% confidence) although it appeared small. It is suggested that the ACL can be an additional indicator for detection of petrogenic hydrocarbons in coastal marine sediments. 相似文献
908.
工厂化鱼类养殖智能系统的研究 总被引:4,自引:0,他引:4
为保证鱼类生长的环境始终处于最佳状态,作者根据狼鲈(Dicentrarchus labrar)的生理特点(耗氧率、氮的排泄率等)建立数学模型,并设计在工厂化水产养殖中采用生物转盘、臭氧(紫外线)消毒器等设备,构建在Windows2000 Visual Basic6.0下运行的环境调控软件包系统,通过计算机技术确定养殖污水处理设备(生物转盘)及增氧、消毒设备的数量及规格,将养殖环境控制在最佳状态。 相似文献
909.
910.
Abstract. The polychaete Perinereis cultrifera ( Grube, 1840 ) (Nereididae) is common along Algerian coasts in algal‐covered hard bottoms. An intensive study was conducted from June 2000 to June 2001 to characterise the life cycle of an intertidal and upper subtidal population of P. cultrifera in Algeria near the Tunisian border (30 km). P. cultrifera has a 3‐year life span and reproduces exclusively by epitoky. The reproductive season is short, and spawning occurs in late April/early May when the sea‐water surface temperature starts rising. Female sexual differentiation starts in February in the second year of life; thus, the oocytes take 16 months to mature and their diameter at maturity is approximately 250 μm. 相似文献