992 resultados para 12-112
Resumo:
Various phosphates and their mixtures were screened for their efficiency of preventing drip loss in frozen prawns. The effectiveness of the phosphates decreased in the following order: Sodium tripolyphosphate — Sodium pyrophosphate — Sodium hexametaphosphate Sodium metaphosphate — Sodium dihydrogen phosphate; the last two being ineffective. Even though thaw drip loss was reduced by the above treatments the organoleptic quality of the thawed as well as cooked products was unsatisfactory, discoloration being the major defect. A solution of a mixture of 12% sodium tripolyphosphate and 8.6% sodium dihydrogen phosphate or 2% citric acid in water when used as dip prevented thaw drip loss, improved cooked yield and organoleptic quality without adversely affecting the biochemical characteristics. Commercial scale trials showed that the results are highly reproducible.
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This study was conducted in five river-estuaries of Satkhira from January to December '96. It was found that during the collection of each Peneaus monodon) post larva (PL), about 45 larvae of other shrimps, 12 individuals of fin-fishes and 530 macro-zooplankters were mercilessly destroyed. It was also recorded that about 11.6 million of P. monodon PLs were harvested annually from the study area. The sh1dy implies that colossal loss of shell and fin-fishes and other plankton resources is done by tiger shrimp fry collectors, and such massive destruction adversely affect the natural productivity and ecological balance of the coastal environment.
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Feeding metabolism in an Indian major carp, Catla catla fingerlings of 10.8+0.56g was investigated in a flow-through water recirculating system. The metabolic energy loss in resting metabolism and feeding metabolism were determined by the indirect method of oxygen consumption followed by multiplication by suitable oxycalorific coefficient. This was done in four metabolic chambers of a respirometer system. Ten fish fingerlings of mean total weight of 109.5, 110.4 and 112.8g/chambers respectively each in two experimental runs of three treatments a, b and c were used. The mean resting metabolic rate during unfed condition showed no significant variation in different treatments. The fish in three treatments a, b and c fed on diets containing 28, 33 and 38% crude protein had significantly different (p<0.05) post-fed SDA magnitude of 497.7, 638.7 and 735.5 mgO2/chamber/day having an equivalent energy loss of 12.68, 14.68 and 15.86 KJ respectively. The SDA co-efficient in three treatments a, b and c were 14.95, 19.00 and 22.36% respectively whereas, respiratory energy - 'R' as % of mean total ingested energy in three treatments were 26.93, 31.17 and 34.74% respectively showing a significant increase (p<0.05) with increase of protein. Feeding metabolism in an Indian major carp (Catla catla Lin.) fed on different protein diets.
Resumo:
基于长期观测资料,众多大气环流模型预测在二十一世纪末大气中二氧化碳浓度将达到700μmolmol'I,地球表面年平均温度也将升高1.5-4.OoC。水稻是亚洲的主要粮食作物,为世界近三分之一的人口提供食物能源。这项工作的目的,是利用人工模拟环境,预测在未来全球气候变化,二氧化碳及温度升高的条件下,水稻的光合生理反应及随之而来的对其产量的影响。本研究是美国环境署( EPA)与国际水稻研究所(IRRI)合作研究项目“Effects of UV-B and Global Climate Change on Rice”的一部分. 在这项研究中,采用了特殊设计并直接建立在水稻田间的开顶式气室(open-top chambers)。在此之前还没有这样大规模的在水稻主产区的此类模拟研究,水稻在气室中渡过了从萌发到收获的整个生长过程。模拟环境条件有三个浓度的二氧化碳(包括现有大气浓度,在此基础上升高200及300 μmolmol-l)和两个温度(即:现有大气温度及升高4度)共六个处理。供试水稻品种四个:IR72,IR65598-112-2,IR65600-42-5-2-BSI-313和N22。在实验中我们发现,水稻品种(如:1R72)单叶光合速率(以二氧化碳气体交换速率计)受二氧化碳浓度促进,在水稻营养生长期,二氧化碳及温度对其光合有协同促进作用.然而,随着花期的到来,在高温条件下,叶片光合能力(photosynthetic capacity)下降,出现光合适应现象(Photosynthetic acclirnation).水稻群体光合作用同样受到二氧化碳浓度促进,但在后期(Grain fill stage)这种促进作用消失;在高浓度二氧化碳下生长的大多数水稻品种的叶片中有较多的碳水化和物(可溶性糖和淀粉)积累.耐高温品种N22叶片中淀粉积累较少:叶片中氮素含量降低,同时发现Rubisco总活性相应降低,这与NCi曲线所示光合效率降低相吻合;通过叶片叶绿素荧光动力学测定,没有发现光系统光能转化效率的变化;水稻籽粒产量随二氧化碳浓度升高而增加,但温度升高使产量降低12.8-36.8%;不同品种对二氧化碳浓度的反应没有显著差别;在高温条件下,耐高温品生长在高二氧化碳浓度下表现良好。 本文系统地研究了水稻光合作用在二氧化碳及温度条件影响下,对二氧化碳浓度及光强变化的反应曲线,初次对水稻单叶与群体光合对二氧化碳浓度变化的反应做了实验性对比;讨论了温度升高对水稻在高浓度二氧化碳下发生光合适应的影响,对光合适应现象的可能机制做了探讨,并提出对未来大气二氧化碳浓度及温度升高条件下水稻适应品种筛选的可能方向。
Resumo:
This work demonstrates transmission at 2.5 Gbit/s across two wavelength-division multiplexing (WDM) network nodes, constructed using counter-propagating semiconductor optical amplifier (SOA) wavelength converters and an integrated wavelength-selective router separated by 45 km of fiber, with an overall penalty of 0.6 dB. Minimal degradation of the eye diagram is evident across the whole system. Full utilization of the capacity of the router would allow an aggregate 360-Gbit/s node capacity for a WDM channel of 2.5 Gb/s.
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The Austrian-Ceylonese hydrobiological mission studied 38 biotopes; 28 of which contain Odonata. From the Zygoptera the Calopterydoidea seem to be the dominant form (22 habitats), while the Coenagrionoidea are scarcer (11 habitats). The most frequent species was Euphaea splendens (Epallagidae - 16 habitats) followed by Vestolis apicalis nigrescens (Calopterygidae, 8 habitats) and Neurobasis chinensis (Calopterygidae, 6 habitats). From the Anisoptera Zygonyx ceylanica (Libellulidae: Zygonictinae) was the dominant form (8 habitats), but some Libellulinae remain undescribed. The number of species varied greatly between different biotopes. The biotopes containing Odonata are small brooks, in which the pH was mostly on the limit between acid and alkaline reaction. They are fast running waters, situated in most cases on lower or middle elevations, only three species being found in higher elevations (1800-2000 m). Adaptations to fast currents and other factors are described.
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An alternative method for seeding catalyst nanoparticles for carbon nanotubes and nanowires growth is presented. Ni nanoparticles are formed inside a 450 nm SiO2 film on (100) Si wafers through the implantation of Ni ions at fluences of 7.5×1015 and 1.7×1016 ions.cm-2 and post-annealing treatments at 700, 900 and 1100°C. After exposed to the surface by HF dip etching, the Ni nanoparticles are used as catalyst for the growth of vertically aligned carbon nanotubes by direct current plasma enhanced chemical vapor deposition. © 2007 Materials Research Society.
Resumo:
To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites.