Geochemistry, microbiology and phospholipid fatty acid content of ODP Site 169-1036 sediments

Phospholipid fatty acids were measured in samples of 60°-130°C sediment taken from three holes at Site 1036 (Ocean Drilling Program Leg 169) to determine microbial community structure and possible community replacement at high temperatures. Five of six samples had similar concentrations of phospholipid fatty acids (2-6 pmol/g dry weight of sediment), and biomass estimates from these measurements compare favorably with direct microscopic counts, lending support to previous microscopic measures of deep sedimentary biomass. Very long-chain phospholipid fatty acids (21 to 30 carbons) were detected in the sediment and were up to half the total phospholipid fatty acid measured; they appear to increase in abundance with temperature, but their significance is not known. Community composition from lipid analysis showed that samples contained standard eubacterial membrane lipids but no detectable archaeal lipids, though archaea would be expected to dominate the samples at high temperatures. Cluster analysis of Middle Valley phospholipid fatty acid compositions shows that lipids in Middle Valley sediment samples are similar to each other at all temperatures, with the exception of very long-chain fatty acids. The data neither support nor deny a shift to a high-temperature microbial community in hot cores, so at the present time we cannot draw conclusions about whether the microbes observed in these hot sediments are active.

Vykopirovka iz plana kolfonda N 169/14

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Vykopirovka iz plana kolfonda N 169/14

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169 GHz repetition rate passively harmonically mode-locked VECSEL emitting 265 fs pulses

High repetition rate passively mode-locked sources are of significant interest due to their potential for applications including optical clocking, optical sampling, communications and others. Due to their short excited state lifetimes mode-locked VECSELs are ideally suited to high repetition rate operation, however fundamentally mode-locked quantum well-based VECSELs have not achieved repetition rates above 10 GHz due to the limitations placed on the cavity geometry by the requirement that the saturable absorber saturates more quickly than the gain. This issue has been overcome by the use of quantum dot-based saturable absorbers with lower saturation fluences leading to repetition rates up to 50 GHz, but sub-picosecond pulses have not been achieved at these repetition rates. We present a passively harmonically mode-locked VECSEL emitting pulses of 265 fs duration at a repetition rate of 169 GHz with an output power of 20 mW. The laser is based around an antiresonant 6 quantum well gain sample and is mode-locked using a semiconductor saturable absorber mirror. Harmonic modelocking is achieved by using an intracavity sapphire etalon. The sapphire then acts as a coupled cavity, setting the repetition rate of the laser while still allowing a tight focus on the saturable absorber. RF spectra of the laser output show no peaks at harmonics of the fundamental repetition rate up to 26 GHz, indicating stable harmonic modelocking. Autocorrelations reveal groups of pulses circulating in the cavity as a result of an increased tendency towards Q-switched modelocking due to the low pulse energies.

Observância do art. 169, § 1º, da Constituição: exigência de prévia autorização e dotação orçamentária para proposição que aumente gastos com pessoal

Consultoria de Orçamento e Fiscalização Financeira

Art. 169 da Constituição e a necessidade de prévia autorização e dotaçao para aumento de gastos com pessoal

Consultoria de Orçamento e Fiscalização Financeira.

The changes in various iron compounds in culture media for algae. [Translation from: Archiv fur Hydrobiologie Supplemente Band 38(1/2) 151-169, 1970.]

The purpose of this work is a contribution to the quantitative record of the use of iron by planktonic algae. Preliminary experiments with Chlorella to determine the rate of iron intake in the presence of inorganic sources of iron did not produce the desired result. The crucial point of this work is the investigation of the influence of various external factors on the stability of FeEDTA (FeEDTA = Ferric(III)-compound of ethylene-diamine tetra-acetic acid), since this compound appears to be particularly well-suited as a source of iron for planktonic algae (e.g. TAMIYA et al. 1953). Cultures of Chlorella fusca in a light thermostat were used in experimental research. Methods and results are discussed.

~(169)Re的转动带结构组态相关性研究(英文)

研究了~(169)Re的高自旋态能级结构,建立了组态为π9/2~-[514]的强耦合带和组态为π1/2~-[541]的退耦合带,推转壳模型(Cranked shell model)计算结果表明组态相关的不同形变能够解释这些转动带的不同带交叉频率,在已知的奇ARe核中,~(169)Re的9/2~-[514]转动带在低自旋时具有最大的能量旋称劈裂,当一对i_(13/2)中子顺排后,旋称劈裂发生了反转,并且劈裂的幅度非常显著地减少了,另外,还观测到了一个三准粒子激发带,并指定了它的最可能组态为π9/2~-[514](?)νAE。

~(169)Re的转动带结构研究(英文)

利用在束γ谱学方法 ,通过反应1 4 4 Sm( 2 8Si,1p3n) 1 69Re研究了1 69Re的激发态能级结构 .实验进行了X γ符合、γ γ符合、DCO系数和带内B(M1 ) B(E2 )比率测量 .基于这些测量 ,建立了组态为π9 2 - [51 4 ]的强耦合带和组态为π1 2 -[54 1 ]的退耦合带 .通过比较1 69Re的转动带与邻近奇质子核已知转动带的结构和B(M1 ) B(E2 )比率 ,指定了1 69Re转动带的组态 .实验观测到π9 2 - [51 4 ]和π1 2 - [54 1 ]转动带的中子AB带交叉的转动频率分别为 0 .2 3和 0 .2 7MeV .着重讨论了1 69Re转动带的中子AB带交叉频率、转动角动量顺排和旋称劈列等 ,并讨论了奇ARe核转动带结构的系统性