997 resultados para 94


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Histochemical experiments are conducted in order to study the interrenal cells of European brook lamprey (Lampetra planeri).

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Pseudomonas aeruginosa has for some time been known as a denitrifier. Pseudomonas aeruginosa was chosen for further studies, because P. aeruginosa occurs abundantly in Plusssee and moreover there are contradictory assertions on the gas products of denitrification by this bacteria. In experimental research the pattern of growth and gas production of Pseudomonas aeruginosa on nutrient broth was studied.

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In freshwater environments of modest size and without notable ecological structure, there is usually present only one diaptomid species. When two or more diaptomid species are present in the same habitat, generally their body dimensions are distinctly different. There are only four examples of co-existence of Arctodiaptomus bacillifer (Koelb.) and Acanthodiaptomus denticornis (Wierz.) situated at higher altitudes alpine lakes. The article discusses the results of sampling in the summer of 1953 and the problem of the co-existence of Arctodiaptomus bacillifer, Acanthodiaptomus denticornis and Heterocope saliens.

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Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.

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The amphipod Gammarus lacustris, a regular representative of lacustrine communities, often plays a significant role in the transformation of matter and energy. The object of the present work was to clarify the quantitative side of the feeding of the amphipod under different conditions of habitation. Experimental works on determination of the rate of consumption of food and its dependence on body-weight were carried out in the summer periods 1975-1978 on three water-bodies of the Krasnoyarsk region, of different conditions of habitation for the amphipods.

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本文对饲料级磷酸氢钙标准(HG2636-94)检测方法中钙含量的测定、氟含量的测定存在的问题进行了探讨,并提出了解决方法.利用分散剂消除磷酸根对钙测定的干扰,EDTA直接络合滴定钙,方法快速准确;控制适当的试科量以保证氟检测结果的准确度.

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The magnetotransport properties of the two-dimensional (2D) electron gas confined in a modulation-doped Zn0.80Cd0.20Se/ZnS0.06Se0.94 single quantum well structure were studied at temperatures down to 0.35 K in magnetic fields up to 7.5 T. Well resolved 2D Shubnikovde Haas (SdH) oscillations were observed, although the conductivity of the sample in the as grown state was dominated by a bulk parallel conduction layer. After removing most of the parallel conduction layer by wet chemical etching the amplitude and number of SdH oscillations increased. From the temperature dependence of the amplitude the effective mass of the electrons was estimated as 0.17 m(0). Copyright (C) 1996 Published by Elsevier Science Ltd

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The development of quantum cascade laser at 2.94 THz is reported. The laser structure is based on a bound-to-continuum active region and a semi-insulating surface-plasmon waveguide. Lasing is observed up to a heat-sink temperature of 70 K in pulsed mode with light power of 4.75 mW at 10 K and 1 mW at 70 K. A threshold current density of 296.5 A/cm(2) and an internal quantum efficiency of 1.57 x 10(-2) per cascade period are also observed at 10 K. The characteristic temperature of this laser is extracted to be T-0 = 57.5 K.

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通过重离子融合蒸发反应16 O(82 Se +4n) 94 Mo布局了94 Mo核的高自旋态 .利用多探头探测器阵列GASP进行了在束γ测量 ,从而重新研究了94 Mo核的高自旋态能级结构 .基于新发现的一些重要的连接跃迁 ,对94 Mo核的高自旋态能级纲图做了重要修改 .将新的能级结构与壳模型计算进行了比较和讨论 .结果表明要正确的描述94 Mo核的高自旋态 (自旋值大于 14 )能级结构 ,应考虑价中子在d5/ 2 ,g7/ 2 和h11/ 2 轨道上的激发 .

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High-spin level structures of 94,95Mo have been reinvestigated via the 16O(82Se, xnγ)94,95Mo(x = 4, 3) reactions at E(82Se) = 460 MeV. The previously reported level schemes of these two nuclei have been largely modified up to ∼11 MeV in excitation energy due to identifications of some important linking transitions. Shellmodel calculations have been made in the model space of π(p1/2, g9/2, d5/2)4 and ν(d5/2, s1/2, d3/2, g7/2, h11/2)2(3) and compared with the modified level schemes. The structures of the newly assigned high-spin states in 94,95Mo have been discussed.