We present the results of a study of the spectra of the compact double system HD 187399. We have measured and identified lines in the spectrum of the main star and computed their equivalent widths, the central residual intensities, and the electron densities in the atmosphere of the main star and the common envelope of the system. We have constructed the curve of radial velocities of the main star and determined the expansion velocity of the common envelope of the system: vr=90 km/sec. We have measured the velocity of the interstellar calcium: vr=–3.5 km/sec. We have established the agreement of the radial velocity curves for the main star obtained in the present paper and in that of Merrill [1]. The comparison enabled us to make the following conjecture: there has been no noticeable loss of mass in the system HD 187399 over the past 35 years, and possibly all that has occurred is a flow of matter from one component toward the other. We note the strong similarity with the Lyrae system.Translated fromAstrofizika, Vol. 38, No. 2, 1995. 相似文献
Twenty-two sediment cores raised from the central and eastern parts of the Barents Sea have been studied to reconstruct the evolution of the facies system since the Late Weichselian glaciation. Multiproxy records reveal four lithostratigraphic units, which reflect major development stages of paleoenvironments. Age control is provided by 23 AMS 14C dates for Holocene sections of four cores. Continental moraine deposits of the last glaciation are overlain by proximal glaciomarine facies of the initial deglaciation phase. During this phase, the Barents Sea ice sheet detached from the ground resulting in seawater penetration into troughs, iceberg calving, deposition of IRD and fine-grained glacier meltwater load in newly formed marine basins. The main deglaciation phase is characterized by pulsed sedimentation from various gravity flows resulting in accumulation of distal glaciomarine facies comprising laminated clay and sand sequences with minor IRD. Redistribution of fine-grained suspended matter by bottom currents and brine-induced nepheloid flows combined with biogenic processes and minor ice rafting caused facies diversity of the Holocene marine sediments. The Holocene facies of shelf depressions reflect rather high, but variable productivity responding to climate changes and variations of Atlantic water inflow into the Barents Sea. 相似文献
To extract electrical energy from sea waves in a commercially and technologically acceptable manner, a number of issues have to be solved. Electricity generation by means of direct conversion of the oscillating gravitational potential energy of a floating buoy can be anticipated, provided a proper design of a generator could be made. This paper deals with the simulation of a novel design for a linear generator aimed for the extraction of energy from ocean waves. The ocean waves are modeled by 4-m-height sinusoidal waves with a characteristic period of 7 s. A wide range of the geometrical sizes, permanent magnets, stator winding, and spring forces acting on the buoy are possible. This paper presents simulations of octagonal three-phase linear generators in the 100-kW power range. The beneficial effects of a stator of octagonal shape are briefly investigated, but not studied in depth. The main emphases in the present study have been to decrease power fluctuations and suppress voltage harmonics. In conventional rotating machines, well-known measures are to use a fractional number of slots per pole and phase, and an additional method is to make the pole edges smoother. These methods are here simulated for the first time on a linear machine aimed for ocean wave-energy conversion and a substantial reduction in power fluctuations and voltage harmonics are predicted. 相似文献
Investments in adaptation are required to reduce vulnerability and strengthen the resilience of food systems to the impacts of climate change. For low-income nations, international financing plays a central role in supporting adaptation. In this article, we document and examine adaptation projects targeting food systems financed through funding bodies of the United Nations Framework Convention on Climate Change (UNFCCC). We find that between 2004 and 2015, 3% (n?=?96) of adaptation projects supported through the UNFCCC explicitly focused on the production, processing, distribution, preparation and/or consumption of food, with US$546 m mobilized through funding bodies directly and US$1.44bn through co-financing. Agriculture is the most common sector supported, with extreme weather events the primary climate change-related impact motivating nations to apply for adaptation financing. The majority of actions are documented to adapt the food production component of food systems, with limited focus within projects on the full range of food system vulnerability and the implications on food security.Key policy insights
Enhanced international adaptation financing targeting food systems is needed, and in particular financing to address limited adaptation readiness
Supported food system projects should include holistic assessments of the entire food system in order to prioritize sector and food system component issue areas for short- and long-term efficiency
To better analyse food system linkages and aid in the prioritization of adaptation activities, adaptation-directed funds should consider placing a higher emphasis on a cross-sectoral approach within projects
Linkages between official development assistance and adaptation-directed funds could help optimize financing for food systems and mainstream food system adaptation efforts
A relic impact structure was recognized within the strewn field of the Agoudal iron meteorite. The heavily eroded structure has preserved shatter cones in a limestone basement, and remnants of autochthonous and allochthonous breccias. Fragments of iron incorporated into the allochthonous breccia have a chemical composition (Ni = 5.16 wt%, Ir = 0.019 ppm) similar to that of the Agoudal meteorite, supporting a syngenetic origin of the strewn field and the impact structure. The total recovered mass of Agoudal meteorite fragments is estimated at approximately 500 kg. The estimated size of the SE–NW‐oriented strewn field is 6 × 2 km. Model calculations with minimal preatmospheric size show that a similar meteorite strewn field plus one small crater with observed shock effects could be formed by fragmentation of a meteoroid approximately 1.4 m in diameter with an impact angle of approximately 60° from the horizontal. However, the most probable is an impact of a larger, 3–4 m diameter meteoroid, resulting a strewn field with approximately 10 craters, 10–30 m in diameter each, plus numerous meteorite fragments. The calculated scattering area of meteorite shrapnel ejected from these impact craters could completely cover the observed strewn field of the Agoudal meteorite. 相似文献
The dynamics of energetic electrons (Ee=0.17–8 MeV) and protons (Ep=1 MeV) of the outer radiation belt during the magnetic storm of May 15, 2005, at high (GOES-10 and LANL-84 geosynchronous satellites) and low (Meteor-3M polar satellite) altitudes is analyzed. The data have been compared to the density, plasma velocity, solar wind, and magnetic field measurements on the ACE satellite and geomagnetic disturbances. During the magnetic storm main phase, the nighttime boundary of the region of trapped radiation and the center of westward electrojet shifted to L ~ 3. Enhancements of only low-energy electrons were observed on May 15, 2005. The belt of relativistic electrons with a maximum at L ~ 4 was formed during the substorm, the amplitude of which reached its maximum at ~0630 UT on May 16. The results are in good agreement with the regularity relating the position of a maximum of the new relativistic electron belt, boundaries of the trapped radiation region, and extreme low-latitude position of westward electrojet center to the Dst variation amplitude. 相似文献