首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8篇
  免费   0篇
安全科学   1篇
环保管理   1篇
综合类   1篇
基础理论   5篇
  2017年   1篇
  2013年   3篇
  2006年   2篇
  2005年   1篇
  2003年   1篇
排序方式: 共有8条查询结果,搜索用时 15 毫秒
1
1.
2.
The nutritional status of the loquat trees was investigated using cattle manure and commercial fertilizers for three years. The farmyard manure increased N, P, K, Mg, Fe and Zn contents of the leaves. No significant difference was found between the fertilizer types for trunk growth. Yield efficiency was nearly doubled by application of farmyard manure. Fertilizers did not affect the weight and shape of the fruits; however, commercial fertilizers led the lower total acidity in fruits. It was concluded that the loquat trees grown in sandy soils could fulfill their principal nutrient requirements for growth and commercial yield with application of farmyard manure.  相似文献   
3.
The objectives of this study were to examine the effect of TDZ and BAP on shoot proliferation and to develop a satisfactory rooting procedure for in vitro propagation of caper (Capparis spinosa L). TDZ was found to be more effective than BAP in shoot production. The highest shoot number per explant (45.7) was achieved on the media that contained 4.54 microM TDZ in the absence of IAA. TDZ at 4.54 microM alone or in combination with 0.57 microM IAA did not inhibit shoot elongation, although they produced the most shoots. Dipping the caper shoots in the solution of IBA at 24.6 microM for 10 minutes before planting on MS media, improved the rooting percentage up to 80.5% under a 16 hr photoperiod.  相似文献   
4.
The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions.  相似文献   
5.
Rockfishes of the genus Sebastes are extensively distributed in the Pacific and Atlantic oceans. Although the occurrence of two morphologically similar species in the Southern Hemisphere, Sebastes oculatus and Sebastes capensis, is now clearly established, the taxonomic status and phylogeographic patterns for the genus in the region have not yet been completely resolved. In this study, we provide new insights into the taxonomy and evolutionary relationships of rockfishes inhabiting the Southwestern Atlantic Ocean, off the coast of mainland Argentina, by combining mitochondrial DNA (mtDNA) control region sequences, microsatellite data, and color pattern analyses. Differences in coloration (“dark” and “light” fish) together with bathymetric segregation between color morphotypes were evident from fish collection and literature review. In addition, the mtDNA phylogenetic analysis and Bayesian clustering analysis using microsatellite data separated the fish into two distinct groups (F ST?=?0.041), most likely representing incipient species. Our results suggest that speciation-by-depth in the absence of physical barriers could be a widespread mechanism of speciation in Sebastes from both the Northern and Southern Hemispheres. Nevertheless, the degree of genetic differentiation found, added to the large number of individuals displaying high levels of admixture, points to the occurrence of incomplete reproductive barriers between color morphotypes. Beyond the taxonomic and phylogeographic implications of our findings, the occurrence of distinct groups of Sebastes off the coast of Argentina being targeted by different fisheries (angling and trawling) has consequences for the design and implementation of appropriate fishery regulations to avoid overharvest of either group.  相似文献   
6.
Gölcük Nature Park (GNP) is an area protected by law in Turkey. It is an important nature park with rich flora, fauna, geomorphologic forms, landscape features, and recreational potential in the region. However, GNP does not have a recreation management plan. The purpose of this study was to determine the actual natural, cultural, and visual resources of GNP, determine the most suitable recreational sites with multiple factors, evaluate the demands and tendencies of visitors, and suggest recreational activities and facilities for the most suitable sites of GNP. However, it was also conceived as leading to a recreational plan and design of GNP in the future and identifying the entire appropriate and current data of GNP with the creation of various maps. This study used multifactor analysis to determine the most suitable recreation sites of GNP. Used recreation factors were established including degree of slope, proximity to water resources, accessibility, elevation, vegetation, soil, climate, aspect, current cultural facilities, visual values, and some limiting factors in accordance with the characteristics of GNP. Weighting and suitability values of factors were determined by 30 local expert surveys. All obtained data were evaluated and integrated in the Geographical Information Systems base. Obtained maps were overlapped. Thus, recreational suitability zones map were created manually. However, the demands and behaviours from visitor surveys in GNP were focused on the most suitable recreation sites of the park. Finally, 10% of GNP was identified as the most suitable sites for recreational use. Various recreational facilities and activities (including picnicking, sports facilities and playgrounds, camping sites, walking paths, food and local outlets, etc.) were recommended for nine of the most suitable areas on the proposed recreational map.  相似文献   
7.
In this study, liquid products obtained from the pyrolysis of hazelnut shell (HS), with and without ultra-high molecular weight polyethylene (UHMWPE), were subjected to the Allium cepa test system. Pyrolysis in conjunction with the A. cepa test is a promising technology not only from the perspective of energy savings and a source of precious material, but in terms of the removal of hazardous material from the environment in safe manner. Dosages of pyrolytic liquids dissolved in water were determined according to lethal dose (LD50), with three different solution concentrations. The preparates were dyed with acetocarmine. The mitotic index decreased and chromosomal aberration, especially stickiness and c-mitosis, increased with dosage and time. The addition of UHMWPE to HS in the pyrolysis process resulted in less harmful chemical agents, as observed by the relatively higher mitotic index and lower levels of chromosomal aberration.  相似文献   
8.
The distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in red mullet (Mullus barbatus) and sediment samples in the eastern Aegean Sea. The data were collected during cruises in July and November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. PAHs were detected in the tissue of Mullus barbatus of different sex and size from nine sampling sites throughout the study area ranging from 0.03 to 0.46 ug/g (fresh weight). The observations show the high levels of PAHs were found in tissues of females. The average concentration of PAHs in Aegean Sea sediments ranged from 0.20 to 1.8 ug/g (dry weight). No significant correlation was observed between PAH and sedimentary organic carbon.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号