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We have identified a companion to the young planetary-mass brown dwarf Oph 162225-240515. This pair forms a resolved binary consisting of two objects with masses comparable to those of extrasolar giant planets. Several lines of evidence confirm the coevality and youth of the two objects, suggesting that they form a physical binary. Models yield masses of approximately 14 and approximately 7 times the mass of Jupiter for the primary and the secondary object, respectively, at an age of approximately 1 million years. A wide ( approximately 240-astronomical unit) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation. 相似文献
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Pfaffl MW Georgieva TM Georgiev IP Ontsouka E Hageleit M Blum JW 《Domestic animal endocrinology》2002,22(2):91-102
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Data on radiocarbon ages of different fractions of humus (humic acids, fulvic acids, and humin) in the profiles of chernozems
are analyzed. A chronoecological grouping of humus in modern and buried (fossil) soils is suggested. An increase in the radiocarbon
age of humic substances down the soil profile has a stepwise character. It is shown that the 14C content in chernozems decreases down the soil profile more somewhat slower than the 12C content. The dependence of a decrease in the humus content of buried soils on the age of burying is traced for a time span
of 800 ka. 相似文献
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Studies on the species composition and structure of parasitoid complex of poplar twig borer,Gypsonoma aceriana (Dup.), on poplar ornamental trees in Sofia and their role in reducing the number of this pest have been conducted during
the period 1990–1997.
Six larval parasitoids—Bracon variator Nees,Orgilus obscurator (Nees),Microdus tumidulus Nees,Apanteles erevanicus Tob. (Braconidae),Pristomerus rufiabdominalis Ucida andPristomerus vulnerator (Panz.) (Ichneumonidae) were identified. Most numerous wereM. tumidulus (41.0%),A. erevanicus (30.6%) andP. rufiabdominalis (19.1%).A. erevanicus andM. tumidulus were dominating during the different years. 相似文献
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Deyan Stratev Teodora Popova Georgi Zhelyazkov Ivan Vashin Lilko Dospatliev Elitsa Valkova 《Journal Of Aquatic Food Product Technology》2017,26(7):871-879
The study was designed to assess the seasonal variations in the quality and lipid profile of mussel meat (Mytilus galloprovincialis) harvested along the Bulgarian coast of the Black Sea. The trial period lasted from June to October, and the sampling was carried out in the area of Varna Bay. Technological quality of the mussels was determined by measuring the water holding capacity (WHC) and cooking and roasting losses. Proximate composition, total aerobic plate count, and fatty acid analysis were carried out. Technological parameters and nutritional quality of the mussel meat were strongly affected by the season. During the summer, the mussels had higher mass, meat content, and meat yield (p < 0.001) compared to the early autumn, which corresponds to the lowest protein content during this season. Lipid profile showed seasonal variations in both individual and total fatty acid amounts (p < 0.001). Saturated fatty acids (SFA) had the highest content in summer, while monounsaturated fatty acids (MUFA) decreased gradually until the autumn. The content of polyunsaturated fatty acids (PUFA) reached its peak in October, contributing to the most favorable values of the nutritional indices of lipids in the early autumn. 相似文献
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