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   12篇
  免费   0篇
林业   2篇
农学   1篇
  3篇
水产渔业   4篇
畜牧兽医   1篇
植物保护   1篇
  2019年   2篇
  2018年   2篇
  2017年   2篇
  2014年   2篇
  2012年   1篇
  2011年   1篇
  2002年   1篇
  1995年   1篇
排序方式: 共有12条查询结果,搜索用时 31 毫秒
1.
A feeding trial on yellow tail cichlid Pseudotropheus acei (Regan 1922) was undertaken to asses the effect of dietary Spirulina meal as a natural carotenoid source. Four experimental diets were formulated to progressively replace 0% (C), 2.5% (SP2.5), 5% (SP5) and 10% (SP10) of fish meal weight. Ten fish per tank (initial weight 3.75?±?0.02?g) were randomly distributed into twelve 80?l fiberglass tanks connected to a closed recirculation system (temperature 26.7?±?0.06°C). The diets were tested in triplicate for 12?weeks. The specific growth rate of fish fed all Spirulina diets were significantly higher compared to diet C. Feed intake (FI) tended to increase with dietary Spirulina level, and fish fed diet SP10 had significantly higher FI values compared to diet C. No significant differences in feed conversion ratio were observed among these groups. Although the protein efficiency ratio of fish fed diet C was lower than that of all Spirulina diets, no significant differences were observed among these groups (P?>?0.05). The total egg production and hatching rate (%) of eggs derived from all fish fed with Spirulina diets was significantly higher compared those from fish fed diet C. The yellow and blue coloration of yellow tail cichlid fed the diet containing Spirulina meal was enhanced and inclusion of dietary Spirulina meal was elevated carotenoids in skin. Results of the present study indicated that Spirulina meal has the potential to enhance the growth, reproductive performance and coloration on yellow tail cichlid.  相似文献   
2.
Long distance transport of various air pollutants has been studied at two Scandinavian coastal sites. The measuring period has covered one year divided into 4 campaigns. Seasonal variations for sulphur and nitrogen compounds as well as anthropogenically emitted metals are reported. Concentrations of Pb and Zn as well as the ratio of V/Ni concentrations have been used to trace sulphuric episodes. Covariation of anthropogenic pollutants for the two sites is demonstrated.  相似文献   
3.
Several viroid species have been reported to infect grapevine in Turkey and there has been not much about their genetic diversity, except Australian grapevine viroid (AGVd, genus Apscaviroid, family Pospiviridae). The viroid was recently detected in Turkish vineyards with very little information about its variability. Therefore, the autochthonous grapevine varieties in two major grape-growing areas in Turkey, i.e. the Eastern Mediterranean and the Southeast Anatolia regions were tested for the prevalance and genetic diversity. The presence of AGVd in the autochthonous varieties was verified by RT-PCR. The incidence of AGVd infection was relatively low in both regions due to self-rooted nature of the plants in the areas. Comparative analysis of local AGVd isolates from these native varieties was performed with viroidal genome sequences from NCBI database. Consequently, AGVd populations in Turkey contained five major sequence variants consisting of three varieties. Four variants had minor sequence variations while one was remarkably diverse.  相似文献   
4.
This study presents a combination of dispersive liquid-liquid-solidified floating organic drop microextraction (DLLSFODM) and slotted quartz tube (SQT) with conventional flame atomic absorption spectrometry (FAAS) to improve the sensitivity for cadmium determination. A ligand namely 2-(4-methylphenyl)-1H-imidazo-[4,5-f]-[1,10]-phenanthroline which has not been used in trace analyte determination was used to form a cadmium complex. Stepwise optimization of parameters affecting complex formation (pH, ligand, and buffer solution) and extraction (extraction and dispersive solvents, salt effect and mixing) was done to maximize cadmium absorbance. The slotted quartz tube was fitted onto the flame burner and optimized to increase residence time of atoms in the flame. Instrumental parameters such as sample and fuel flow rate were also optimized to further enhance the absorbance signal for cadmium. Using optimal parameters and values, the limits of detection and quantification were determined to be 0.81 and 2.69 μg L?1, respectively. Low percent relative standard deviations (<?6.0%) indicated good precision for both extraction and instrumental measurements. Recovery tests were used to determine the accuracy of the method and the recovery results obtained were between 88 and 113%.
Graphical Abstract ?
  相似文献   
5.
This paper analyses the major determinants of long‐ and short‐run labour productivity evolution for Chinese provinces between 1978 and 2010. The role played by openness to trade and foreign direct investment (FDI) constitutes the main focus of this analysis. From a methodological perspective, our main contribution is the inclusion of spatial effects into a dynamic error correction modelling framework. The results show that, in addition to domestic factors such as investment intensity and infrastructure use, trade openness and inward FDI also exert a direct impact on labour productivity. Furthermore, the geographical environment has a strong indirect influence on productivity: The more a region is surrounded by high‐productive regions with good infrastructure and linkages to the world economy, the higher are its productivity level and growth rate. The magnitude of these impacts varies by spatial regime (coastal, interior provinces) and time period in focus. Especially in the recent past, trade and FDI activity appear to be increasingly important drivers of regional productivity evolution, both for coastal and interior regions. These findings have important policy implications: In order to fully exploit the benefits from such spillovers, coordinated industrial policies which foster regional complementarities and support the free movement of production factors across regional borders are crucial.  相似文献   
6.
Water, Air, & Soil Pollution - Sustainable groundwater quality has become a major concern for the agro-based country like Bangladesh. Integrated approaches of various irrigation water quality...  相似文献   
7.
This study was carried out to determine the effects of fish meal or plant‐based diets with supplementation of dietary Spirulina (4%) on shelf life of rainbow trout, Oncorhynchus mykiss. Rainbow trout (initial weight: ~135 g) were fed four experimental diets (fish meal‐based FM, plant meal‐based‐PM, Spirulina included at 4% of fish meal‐based‐FM/S or plant meal‐based PM/S) for 12 weeks. After the feeding trial, trout were stored on ice at 4°C for 0, 5, 10, 15 and 20 days. The chemical, microbiological and sensory analyses of fish were subjected to each sampling days for flesh quality evaluation. TBA of supplemented dietary Spirulina was lower than that non‐supplemented dietary Spirulina. pH values of all groups decreased significantly between days 0 and 20 during the storage period (p < 0.05). Luminosity (L*) value of all groups increased with time in storage period. Fish fed Spirulina supplemented diets showed an increased red/green tonality (a*) (p < 0.05) compared with fish fed non‐Spirulina supplemented diets. In the end of the storage period, the total coliforms values of fish fed with PM/S diet lower than that of other all diets. In conclusion, dietary Spirulina could be allowed the shelf life of the rainbow trout to be extended.  相似文献   
8.
Cultivation of a species or population and distribution to various regions has raised the idea of negative impacts on native species. The effect of non‐native species on native species may be caused by competition for source, predation, hybridization, and parasite/disease transport. The present study aims to evaluate the possible effects of a trout farm established on the banks of Kocaba? Stream (Çanakkale, Turkey) on feeding characteristics of some freshwater fish (Phoxinus phoxinus, Barbus oligolepis, and Squalius cii). The samples were collected monthly over a year at two stations located before and after the trout farm and at a control station on the tributary not impacted by the effects of the farm. Fish and environmental samples were gathered monthly with an electroshocker and some fishing tools between August 2015 and July 2016. The fish diet and resource incorporation into biomass were evaluated by gut content and stable isotope analyses. Changes in diet preferences when the species are exposed to source stresses and some individuals fed on farm‐based feed contaminated from the farm in Kocaba? Stream. In this study, it was observed that native fish populations in aquaculture regions were influenced by diet preferences. Designing enclosed systems limiting feed and waste transit in aquaculture establishments may be suitable for sustainability of these species.  相似文献   
9.
Fertility variation and effective number of parents were estimated in the 100 individuals from each of three plantation populations (P1, P2 and P3) of the endangered Pinus nigra. subsp. pallasiana var. pyramidata established in the Isparta–Golcuk district in southern Turkey in 1990. Potential relations between cone yield and growth characters (height, diameter at breast height, diameter at base and crown diameter) were also investigated. Large differences were found among populations and within populations for cone production and growth characters. Mean cone production was eight (ranging from 6.5 in P2 to 9.1 in P1) for the three populations. The 10 most productive individuals for cones produced 32% of the total cones in P1, 39% in P2 and 34% in P3; 21, 16 and 6 individuals, respectively did not produce any cones in the populations. According to the correlation analyses, the relation between cone yield and growth characters changed for the populations, while height, diameter at breast height and crown diameter were positively significantly correlated (r = 0.182, 0.135 and 0.209; p ≤ 0.05) with cone production for the three populations. Fertility variation was 1.81 in total of three populations, ranging from 1.72 in P3 to 3.45 in P1). Effective number of parents was 142 (55.2 of number of parents censused; 29%, P1; 49.8%, P2; 58.3%, P3).  相似文献   
10.
Cavalier King Charles Spaniels (CKCS) often have idiopathic asymptomatic thrombocytopenia. In affected dogs, the thrombocytes often are large, and it has been speculated that the condition could be an inherited macrothrombocytopenia. The aim of this study was to examine the inheritance of idiopathic, asymptomatic thrombocytopenia in CKCS. Sixteen families (both parents and > or = 3 offspring) of privately owned CKCS were included. There were 105 clinically healthy dogs (50 from Denmark and 55 from Sweden): 81 offspring and 26 parents (2 dogs had both roles). Because autoanalyzers have difficulty counting large platelets, the platelets were counted manually, with a counting chamber. Platelet counts were not influenced by age, gender, or heart murmur status. Thrombocytopenia (< or = 100,000 platelets/microL) was found in 46% of the parents. The pedigrees indicated that thrombocytopenia segregated as an autosomal recessive trait and that 100,000 platelets/microL was appropriate as a lower limit of normal. Affected offspring were found in all families, showing that all of the included parents were at least carriers. Therefore, the expected segregation ratios (which were in good accordance with the observed ones) were 1:0, 1:1, and 1:3 for the 3 crosses: affected x affected, normal x affected, and normal x normal. Within a given cross, the mean parental platelet count had no influence on the platelet counts of the offspring. We conclude that idiopathic, asymptomatic thrombocytopenia in CKCS is inherited in an autosomal recessive manner. The condition most likely constitutes an inherited macrothrombocytopenia in dogs.  相似文献   
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