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101.
Abstract –  The fish assemblage of the floodplain of the Mamoré River (Bolivia) was estimated in eight lakes, corresponding to four habitat types, situated on an environmental gradient related to the river distance: lakes situated near the river, in the forested floodplain, at the floodplain edge and lakes isolated in the savanna. This paper documents the diet of 71 fish species (among the 140 recorded) and compares the taxonomic and trophic structure of fish assemblages between four lake types. The diet analysis was conducted to determine five trophic guilds: algivores/iliophages, herbivores, zooplanktivores, invertivores and piscivores. The taxonomic and trophic structures of the fish assemblages were not similar in the different lake types of the Mamoré River. The trophic structure of assemblages showed a coarse pattern of dominance of algivores/iliophages and invertivores, but different situations were observed in relative abundance of the trophic groups in relation to the spatial position of the lakes (except for piscivores). Lakes close to the river appeared more favourable to the microphages (algivores/iliophages, zooplanktivores) although remote lakes appeared more favourable to the macrophages (invertivores, herbivores). These results support the general idea that fish distribution follows a pattern linked to the ecology of the species, and related to environmental characteristics of the lakes.  相似文献   
102.
草坪及其植物配置的探讨   总被引:1,自引:0,他引:1  
对草坪的主景树,隔离树丛,庇阴树的配置作了分析和探讨。认为只有将树木,草花与草坪合理搭配起来,才能创造出优美的植物景观。  相似文献   
103.
To study the importance of the effects of genotype–environment interactions on the yield of pigeonpea ( Cajanus cajan L. Millsp.), 10 early-maturing genotypes were grown in a randomized complete block design with three replications in a total of seven environments spread over five regions of Kenya between 1987 and 1988. Results indicated the presence of a substantial genotype–environment interaction effect on grain yield. The observed significant genotype–environment interaction effect is discussed in relation to its importance in pigeonpea grain yield evaluation studies. It is noted that the best genotype in one environment is not always so in other environments. Results from regression analysis indicated that this method of analysis is appropriate for describing the response of pigeonpea genotypes grown in a number of locations. Analysis of variance showed significant additive and multiplicative genotype–environment interaction effects. Only the first interaction principal component axis (IPCA) was found to be important in describing the multiplicative interaction effects. The additive main effects and multiplicative effects (AMMI) model allowed the partitioning of interaction variance into agronomically important sources (genotype groups), and the specific genotype × environment patterns that are the basis of these sources of variance were examined.  相似文献   
104.
本文详细论述了国际公寓工程施工中的几个关键环节:如施工机械的配备、布置,现浇混凝土工程的施工及施工中的测量控制等,为组织高层建筑施工人员提供了实践经验。  相似文献   
105.
国际合同是国际交易的主要形式,由于国际贸易的自由化,为与国际接轨,应扩大国际合同的主体范围。当事人共同选择的法律、与合同有最密切联系的法律和国际统一实体法是解决国际合同争端的主要法律依据。由于先决问题的存在,还会涉及到多个法律的适用。  相似文献   
106.
介绍了一种对含有多种纹理结构的图像的纹理主频检测——香农小波包分解的纹理主频检测 ,然后利用 Gabor滤波器确定主频 ,最后应用边缘提取实现纹理分割  相似文献   
107.
社会发展和高等教育的大众化对高校教师主体性作用的发挥提出了更高的要求。高校教师应积极适应社会发展与教育变革需求,重塑主体性作用,以知识的力量引导人、以智慧的力量说服人、以情感的力量感染人。  相似文献   
108.
The aim of this study was to assess brown rust resistance of new sugarcane varieties bred in China and main cultivated varieties in sugarcane planting area, and screen the elite new brown rust resistant varieties for popularization and application in production. In total, 60 new varieties in the national regional test of new sugarcane varieties were tested in Kaiyuan and Lincang, and 34 main cultivated varieties were studied in Lincang, Puer, and Yuxi, Yunnan province, and Yizhou, Guangxi province, China, where the incidence of brown rust was particularly high. The resistance of these sugarcane varieties to brown rust was investigated under natural inoculation and molecular marker-assisted identification was used to detect the brown rust resistance gene Bru1. The results of field survey showed that 66 (70.21%) of the 94 new and main cultivated varieties were highly resistant to moderately resistant, and 28 (29.79%) were susceptible to highly susceptible. Molecular detection indicated that Bru1 gene was found among 54 (57.45%) of the 94 new and main cultivated varieties. Some main cultivated varieties that were currently planted across large areas such as Guitang 29, Guitang 44, Dezhe 03-83, Liucheng 03-1137, Yuetang 60, and Guitang 46 were highly susceptible to brown rust, and 31 new varieties such as Yuegan 48, Funong 09-2201, Guitang 08-120, Liucheng 09-15, Zhongzhe 1, Yunzhe 08-1609, Yunrui 10-187, and Zhongtang 1201 were resistant. Therefore, in the sugarcane planting areas with high incidence of brown rust and wet and rainy climates, more effort should be eliminated the main susceptible varieties and promoted the application of new resistant varieties. This will help to achieve a reasonable distribution of varieties, fundamentally control the outbreak of disease in sugarcane planting areas, and provide security for the high-quality development of sugarcane industry in China in the future.  相似文献   
109.
小麦主茎总叶数的变异   总被引:9,自引:1,他引:9  
小麦主茎总叶数是重要的植株性状。它也具有变异性。春型品种的主茎叶数少,冬型品种的主茎叶数多,过渡型品种居中。在不同播期中,强春性小麦的主茎叶数相近,一般春性品种变化不大。随着播期的推迟,过渡型和冬型品种的主茎总叶数逐渐发生变化,冬型品种的变化幅度大。冬播期中,在翌春出苗的情况下,所有品种的主茎总叶数都较少,  相似文献   
110.
In this paper, we propose a method to solve the problems with stochastic nonlinear and point to point architecture of the wind turbines. The proposed method presents an open motion control architecture and a linearized torque control system based on power curve LUT. We reference the PLCopen motion control standard that is used to design the linearized torque and pitch systems of the wind turbines. This proposes a new methodology for the main controller design and the system integration of wind turbines.  相似文献   
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