共查询到20条相似文献，搜索用时 31 毫秒
1.
The possible application of a Rindler type reference frame for studies of physical processes near the horizons of black and white holes is considered. New similar reference frames inside black and white holes in the region T of a Kruskal wormhole are introduced. 相似文献
2.
A supernova explosion in a close binary system in which one of the components is a compact magnetized object (neutron star or white dwarf) can form a narrow “tail” with length l t ～109 cm, width h t ～108 cm, and magnetic field B t ～106, due to the resulting shock wave flowing around the magnetosphere of the compact object. The energy released by the reconnection of magnetic field lines in this tail can accelerate electrons to relativistic speeds (γ≈104), creating the conditions required for powerful synchrotron radiation at energies from hundreds of keV to several MeV, i.e., for a gamma-ray burst (GRB). The duration of this radiation will depend on the power of the shock that forms during the supernova. If the shock is not sufficiently powerful to tear off the magnetosphere tail from the compact object, the duration of the GRB will not exceed l t /V A ≤1 s, and the conditions necessary for an “afterglow” at softer energies will not arise. If the shock is more powerful, the tail can be torn from the magnetosphere, forming a narrow ejection, which is perceived in its relativistic motion toward the observer(Γ～104) as an afterglow whose duration grows from tens of seconds at gamma-ray energies to tens of days in the optical. This may explain why afterglows are observed only in association with long GRBs (T 90>10 s). Very short GRBs (T 90<0.1 s) may be local, i.e., low-power, phenomena occurring in close pairs containing compact, magnetized objects, in which there is again an interaction between the magnetosphere of the compact object and a shock wave, but the shock is initiated by a flare on the companion, which is a red-dwarf cataclysmic variable, rather than by a supernova. 相似文献
3.
Clinoenstatite crystals from a boninite and the Yamato-74191 chondrite have been studied with an analytical electron microscope. (100) twins and cracks perpendicular and parallel to the c axis are characteristic of their submicroscopic textures. The frequency in appearance along the c axis and widths of the cracks have been explained by the dimensional change of the c axis in the direct transformation of protoenstatite to clinoenstatite and by the cooling rate around the transformation temperature. The cracks in the crystals from the boninite are filled with fibrous crystals of talc, while those from the chondrite are open or filled with glass in which fine crystals of plagioclase are common. 相似文献
4.
Seasonal patterns of microbially-mediated nitrogen cycling via the nitrification-denitrification pathway were compared between a natural and a restored salt marsh. Sedimentary denitrification rates, measured with a modification of the acetylene block technique, were approximately 44 times greater in the natural marsh relative to an adjacent transplanted marsh. Nitrification rates were similar at both sites. The difference in denitrification rates was attributed to oxygen inhibition at low tide and tidal flushing of porewater nutrients at high tide in the coarse sediments of the restored marsh. Denitrification was positively correlated with nitrification throughout the year in the natural marsh with a seasonal fall peak in denitrification corresponding to a maximum in porewater ammonia concentration. A weak correlation existed between the two processes in the restored marsh, where nitrification rates exceeded denitrification rates by a factor of 20. Transplanted marsh denitrification rates exhibited a spring peak, corresponding to elevated porewater ammonia concentrations. Our findings demonstrate functional differences in microbial nitrogen dynamics of a young (0–3 yr) restored marsh relative to a mature (>50 yr) salt-marsh system. *** DIRECT SUPPORT *** A01BY070 00008 相似文献
5.
This paper presents the construction and performance details of a compacted London Clay barrier that was designed to prevent any leachate or methane penetrating a stretch of the cut and cover box section tunnel of the London Heathrow Express Rail Link. The barrier was constructed with London Clay that was spoil from concurrent bored tunnelling operations on adjacent sites. Laboratory investigations carried out on the compacted London Clay are presented in the paper. These indicated that it was possible to design the clay surround to function as a barrier protecting the structure from the ingress of the leachate. Field monitoring using magnetic extensometer gauge measurements indicate that the consequent ground movements are lower than that predicted by the laboratory tests. 相似文献
6.
A. I. Tsygan 《Astronomy Reports》2007,51(2):97-99
We show that a quasar (or active galactic nucleus) emitting a one-sided jet (or displaying asymmetry in its emission of particles and photons) can be accelerated, causing it to be ejected from its galaxy. 相似文献
7.
Origin and evolution of a migmatite 总被引：5，自引：0，他引：5
The development of a stromatic migmatite exposed east and southeast of Arvika (Western Sweden) is described in four stages beginning with the country rock and following evolution through three areas characterized by low, medium and high amounts of leucosomes (areas L, M, and H, respectively).The country rock is a paragneiss composed of thin, alternating fine- and coarse-grained layers. Composition of the layers varies from granitic (fine) to tonalitic (coarse layers).The bulk of the stromatic migmatite is composed of leucocratic layers of magmatic appearance (leucosomes) and darker layers of gneissic aspect (mesosomes). Petrographical and chemical data (given in the form of Niggli values and K2O/SiO2 diagrams) show a close relationship between the fine-grained paragneiss layers and the leucosomes on the one hand and between the coarse-grained layers and the mesosomes on the other.At relatively low temperatures only those gneiss layers with a suitable (granitic) composition are transformed into leucosomes. This process is interpreted to be due to recrystallization of the felsic minerals via partial melting and to the separation of biotite.With increasing metamorphism, leucosomes become broader and more frequent due to partial melting of layers with less suitable composition. Contacts between different generations of leucosome can be recognized in the form of relict melanosomes.These observations favour essentially isochemical melting, followed by later in-situ crystallization. This model of an isochemical layer-by-layer transformation is supported by the preferential formation of hornblende in leucosomes and relict melanosomes, as well as by almost identical compositions of migmatite and country-rock plagioclase. 相似文献
8.
9.
A. J. Prakash P. Palroy D. D. Misra 《Fragblast: International Journal for Blasting and Fragmentation》2004,8(1):51-60
This paper presents the influence of various discontinuities, natural or artificial, on magnitude and frequencies of blast induced ground vibrations. These discontinuities were geological faults, a pond, a shaft incline, a trench and a pre-split plane interposed in the path of vibration propagation. In the post-trench region, ground vibrations in terms of peak particle velocity were significantly reduced and dominant frequencies in higher bands were consequently observed. Depth of trench with respect to blastholes were varied and consequent vibration characteristics were analyzed. The techniques of creating a trench and pre-split plane were successfully implemented in controlling vibration and in increasing the explosives charge to meet the scheduled production target of an opencast mine. Comparisons of ground vibration characteristics affected by a trench and a pre-split plane of the same depth are described in the text. The findings lead to the conclusion that such experimental data are necessary for production blasting in open cast mines under constrained conditions. 相似文献
10.
Wanghua Sui Jinyuan Liu Siguang Yang Zhongsheng Chen Yisheng Hu 《Environmental Earth Sciences》2011,62(4):735-749
This paper presents a case history of the permanent salvage of the Sanhejian Coalmine in China after a sudden groundwater
inrush, which includes emergency responses, hydrogeological analyses, and design and performance of bulkheads. The inrush
accident occurred in October 2002 in the mined-out area with a high water pressure of 7.6 MPa and a high water temperature
of 51°C. The emergency response quickly followed up to provide the time required to perform a detailed hydrogeological analysis
to identify the source and pathway of groundwater. The Sanhejian Coalmine is geologically located in the Tengxian anticline
hydrogeological setting. The Sunshidian fault, the northern boundary of the mine, was assumed impermeable in the original
hydrogeological report. After the accident and hydrogeological analysis, this assessment was revised and the fault was considered
to be permeable. The Sunshidian fault connects the strata in the mine and the excellent water-productive Middle Ordovician
Majiagou Formation in the core of the Tengxian anticline. It was concluded that the water inrush was from the underlying Ordovician
karst aquifer and the pathway was a hidden tectonic structure in the strata overlying the aquifer. This assessment served
as the guideline for salvaging the mine in this project. After a detailed technical and economic analysis, a concrete bulkhead
design was selected from several alternatives including dewatering and surface grouting. The performance of the bulkheads
has been sufficient for the last 6 years since their construction. This case history shows that the hydrogeological analysis
plays an essential role in successfully salvaging the coalmine from the water inrush by identifying the source and pathway
of groundwater. 相似文献
11.
Yu. V. Alekhin S. M. Ilina S. A. Lapitskiy M. V. Sitnikova 《Moscow University Geology Bulletin》2010,65(6):380-386
This work describes the evolution of migration forms of true dissolved compounds and colloidal entities using an integrated
approach with molecular mass distribution and differences in the association of trace elements with organic matter and Fe-oxide
colloids in the soil water-bog-river-lake system. One major problem is obtaining reliable information on the processes of
redistribution deposited forms and trace element complexes during the phase transformation of organic humic compounds in a
series of high-molecular-weight organic matter of bog soils to colloidal and truly dissolved forms, as well as to the river
and lake fine sediment (suspension) as a transit zone and deposit region. 相似文献
12.
This study examined the environmental factors influencing the distribution and abundance of hydrobiid snails in two estuaries on the northeastern coast of Argentina in a coastal lagoon (Mar Chiquita, 37°40′S, 57°20′W) and a partially mixed estuary (Quequén Grande, 38°30′S, 58°45′W). Five intertidal study sites in each estuary represented a gradient in environmental conditions. Variations in the main environmental factors and in the abundance of hydrobiids were assessed both spatially and seasonally. The three species wereHeleobia australis, Heleobia conexa, andHeleobia parchappii, and they were primarily distributed across a salinity gradient. This pattern was clearly recognizable in the partially mixed estuary, where the abundance ofH. australis decreased as salinity decreased, and the abundance ofH. conexa gradually increased towards the inner reaches of the estuary.H. parchappii was restricted to areas far away from the influence of the tide. Slight differences in the distribution patterns of these species between Quequén Grande and Mar Chiquita were refated to the different dynamics of environmental factors in each estuary. 相似文献
13.
J. Tuzo Wilson 《地学学报》1990,2(6):519-538
Early geologists considered that the Earth's surface is rigid and unchanging. They assumed that the whole Earth is static, except for enough sub-surface contraction to build mountains. After seismology developed, most geophysicists agreed. A few scientists, notably Wegener, favoured a more mobile Earth. About 1965 fresh evidence showed that both theories were too simple. This evidence explained why neither theory had been able to relate the whole Earth's behaviour to laws of physics. Hence different aspects of geology had only been solved separately which had fragmented Earth science. This paper proposes a compromise. It is that the rigid lithosphere fractures according to Navier's law of brittle failure which explains the properties and provides methods for classifying faults, plate boundaries and mountains and that the ductile mantle convects by laws of fluid flow in patterns partly controlled by lithospheric fractures. These dual, interacting influences explain tectonic behaviour. The pattern of currents is hidden. At any one time upwelling beneath continents only affects a few limited areas; today some are in southwestern United States, Central Asia, Botswana, Antarctica and rifts in East Africa, Europe and Siberia. Nevertheless recognition of upwelling currents may revolutionize geology because their cumulative effects have been great and neglected. 相似文献
14.
Post-failure behavior of a granite and diabase 总被引：9，自引：0，他引：9
SummaryPost-Failure Behavior of a Granite and Diabase Compression experiments have been performed on Westerly granite and Frederick diabase at a mean strain rate of 0 (10–5) sec.–1. In such tests Westerly granite and Frederick diabase exhibit Class II failure behavior between zero and 22000 psi and between 500 psi and 2200 psi, confining pressure respectively. In order to control brittle failure in these rocks, therefore, energy must be extracted from the samples.Complete stress-strain curves for Westerly granite can be divided into a number of characteristic regions. Each of these regions can be described in terms of distinct fracture patterns. In Westerly granite in uniaxial compression and at less than 2 900 psi confining pressure, the fracture patterns consist of local cracks predominantly parallel to the direction of greatest compression, slabs and narrow intensely crushed shear zones. At greater 2 900 psi confining pressure the fracture patterns consist of local cracks predominantly inclined to the direction of greatest compression and of macroscopic shear fractures. At high confining pressure, local cracks tend to propagate in their initial plane. The fracture patterns in Frederick diabase are sensibly the same as those in Westerly granite at 22000 psi confining pressure.The ultimate strength of Westerly granite above 22000 psi confining pressure and in Frederick diabase is controlled by faulting. At lower confining pressure faulting in granite occurs only in the post-failure region beyond the peak of the stress-strain curves.Preliminary experiments suggest that creep in Westerly granite under high and constant stress produces the same fracture patterns that occur in the post-failure region in continuous-deformation tests. In uniaxial compression creep terminates in macroscopic fracture near the intersection of the constant stress-strain path of a creep sample with the post-failure branch of the stress-strain curve of a quasi-statically loaded specimen.A comparison of all fracture patterns suggests that the fracture mechanisms in rock depend upon confining pressure, mineral composition and grain size of the rocks tested. It is unlikely, therefore, that rock failure in compression can in general be described by a single failure criterion.
With 12 Figures and 5 Plates 相似文献
ZusammenfassungVerhalten von Granit und Diabas nach dem Bruch Druckversuche an Westerly-Granit und Frederick-Diabas bei einer mittleren Stauchungsgeschwindigkeit von 0 (10–5) sec–1 haben ergeben, daß Granit in den Grenzen von Null bis 22000 psi Manteldruck und Diabas zwischen 500 psi und 2200 psi Manteldruck ein Bruchverhalten der Klasse II aufweisen. Um den Bruchvorgang im post-failure-Bereich zu kontrollieren ist es daher notwendig, daß den Prüfkörpern Energie entzogen wird.Vollständige Kennlinien von Granit und Diabas können in eine Reihe von charakteristischen Abschnitten unterteilt werden, die jeweils bestimmte und ihnen eigene Brucherscheinungen aufweisen. Bei einachsiger Belastung und im Triaxialversuch unterhalb 2900 psi Manteldruck bestehen die Brucherscheinungen in Westerly-Granit aus feinen, über den Probekörper verteilten Haarrissen, vornehmlich parallel zur Auflast, aus Schalen sowie aus dünnen, intensiv aufgemahlenen Scherzonen. Der Makroskopische Bruch erfolgt als Verschiebungsbruch. Oberhalb 2900 psi Manteldruck entstehen Haarrisse, die vornehmlich zur Auflast geneigt sind und die bei fortschreitender Verformung des Prüfkörpers in ihrer ursprünglichen Ebene weiter aufreißen. Der sichtbare Bruch erfolgt bei hohem Manteldruck als Gleitungsbruch. Die Brucherscheinungen in Frederick-Diabas sind denen in Westerly-Granit bei 22000 psi Manteldruck nahezu gleich.Die Bruchfestigkeit von Westerly-Granit bei 22000 psi Manteldruck und in Frederick-Diabas ist von der Ausbildung von Gleitungsbrüchen bestimmt. Bei niedrigerem Manteldruck entstehen Gleitungs- oder Verschiebungsbrüche in Granit jedoch erst im post-failure-Bereich nach teils erheblicher Überschreitung der Bruchfestigkeit.Vorläufige Ergebnisse deuten darauf hin, daß das Kriechen in Westerly-Granit unter hoher Spannung durch die gleichen Brucherscheinungen hervorgerufen oder von ihnen begleitet wird, die im post-failure-Bereich in quasi-statischen Versuchen beobachtet werden können. Im einachsigen Druckversuch führen Kriecherscheinungen ungefähr dann zum Bruch, wenn die Kennlinie einer Kriechprobe die Kennlinie eines ebenfalls einachsig aber quasistatisch belasteten Prüfkörpers im post-failure-Bereich schneidet.Ein Vergleich der Brucherscheinungen in einigen Gesteinen läßt darauf schließen, daß sich die Bruchmechanismen in Gesteinen mit der Höhe des Manteldrucks und mit der Beschaffenheit des Gesteins ändern. Es ist daher unwahrscheinlich, daß der Bruch von Gesteinen mit Hilfe eines einzigen Bruchkriteriums hinreichend beschrieben werden kann.
RésuméComportement post-rupture d'un granite et d'une diabase Au cours d'expériences en compression à vitesse de déformation constante (10–5 sec–1) le granite de Westerly et la diabase de Frederick ont un comportement à la rupture dit de classe II pour des contraintes latérales variant entre 0 et 1500 bars pour le granite, et entre 30 et 150 bars pour la diabase. Il faut donc extraire de l'énergie des éprouvettes pour en contrôler la cassure.Les courbes complètes effort-déformation du granite de Westerly peuvent être divisées en un certain nombre de régions caractérisées chacune par un réseau de fracture particulier qui dépend d'ailleurs aussi de la contrainte latérale. Lorsque celle-ci est nulle, ou inférieure à 200 bars, le granite de Westerly développe un réseau de fracture consistant en plaques, en étroites zones de broyage intense et en fissures essentiellement parallèles à la direction de compression maximale. Lorsque la contrainte latérale est supérieure à 200 bars, le réseau de fractures consiste en fractures de cisaillement macroscopiques et en fissures locales faisant pour la plupart un angle avec la direction de compression maximale. Pour des contraintes latérales élevées, les fissures locales ont tendance à se propager dans leur plan initial. Le réseau de fractures développé dans la diabase de Frederick, quelle que soit la contrainte latérale, est à peu près identique à celui qui se développe dans le granite de Westerly pour une contrainte latérale de 1500 bars.Au dessus de 1500 bars de contrainte latérale, la charge de rupture des deux roches est régie par la formation d'une faille, alors qu'en dessous de 1500 bars une faille ne se forme dans le granite que dans la région qui suit la rupture, au delà du maximum de la courbe effort-déformation.Des expériences préliminaires suggèrent que le fluage du granite de Westerly soumis à des contraintes constantes élevées produit un réseau de fracture identique à celui obtenu dans la région qui suit la rupture dans des essais de déformation continue. En outre, en compression uniaxiale, le fluage se termine par une fracture macroscopique près de l'intersection de la courbe de déformation à charge constante avec la partie décroissante de la courbe complète effort-déformation d'une éprouvette chargée de façon quasi-statique.Une comparaison de tous les réseaux de fracture obtenus suggère que les mécanismes de fracture dépendent de la contrainte latérale, de la composition minéralogique et de la taille des grains de la roche éprouvée. Il est donc peu probable que la rupture des roches en compression puisse être en général décrite par un seul critère.
With 12 Figures and 5 Plates 相似文献
15.
Partial syntectonic recrystallization has been produced in an experimentally deformed plagioclase (peristerite An4.5). The recrystallized grains are scattered through the strongly deformed matrix and appear to have developed by a nucleation and growth mechanism. 相似文献
16.
Xuanwen LU Xueqin TAO Zhi DANG 《中国地球化学学报》2006,25(B08):115-116
Chloramphenicol （CAP） is an antibiotic commonly used in aquaculture as a prophylactic or disinfectant to prevent diseases, or as a chemotherapeutic agent to control diseases. This antibiotic is either spread directly in the aquatic environment or administered through medicated feeds. It may be directly exposed to or enter the environment by leaching from uneaten feeds or from the aquatic animals＇ excrements. The antibiotic also directly enters the environment through pharmaceutical wastewater. Toxicity of CAP to human bone marrow has been linked to fatal aplastic anemia. Antimicrobial residues enter the environment, which may also establish a selective pressure in favour of antimicrobial-resistant bacteria. The residues of antibiotics may pose potential risk to public health or increase the occurrence of antibiotic-resistant bacteria in the aquatic environment. Due to these perceived risk, treatment of CAP in farm animals intended for human consumption has been restricted. However, residue of CAP in the environment is still a concern. There have been some reports on the residual effects of CAP on aquaculture and on microbial resistance to CAP in certain environments. The biotransformation of CAP in aquaculture pond sediments has been reported, which indicated that salinity is one of the many environmental factors that affect the degradation of CAP. However, acclimatization and screening of dominant bacteria for biodegrading CAP have been rarely studied. This paper studied the microbial degradation of CAP. In order to screen the dominant bacteria for degrading, the source of bacteria was sampled from the aquaculture pond sediments of Baiyun Borough, Guangzhou, China. 60 mg/L CAP was used as a sole carbon source to screen CAP-degrading bacteria and the dominant bacteria were acclimated after 2 months. 相似文献
17.
Colloids are known to transport contaminants over long distances in natural media. Despite this potentially harmful effect,
very few studies have been undertaken in subsurface aquifers. This paper presents the first results of a study of natural
colloids and particles in a karstic aquifer. The site was chosen for its coverage by clay layers and peat which deliver various
and numerous particle types in water. The methodological part describes three methods used for size determination and sample
fractionation of surface water and spring water. These methods have been adapted for the treatment of multiple samples due
to the rapid discharge variation typical of karstic aquifers. The analysis of many particle size distributions (PSD) shows
that they can be described by a Pareto law. The variation of the slope of the PSD at the spring is mainly dependent on discharge.
This behavior is interpreted as a washing of the karstic drains during the first phase of high flow events. Fractionation
of the samples allowed application of various characterization techniques to particle size classes. X-ray diffraction (XRD)
patterns showed that most of the mineral particles originated from Quaternary deposits and limestones. However the use of
scanning electron micrsocopy with energy-dispersive spectrometer (SEM-EDS) detailed the composition of individual particles
and revealed particles not found by XRD. These techniques also showed the high complexity of the natural particles and the
important place of coprecipitation in their formation. Consequences on the fluxes of particulate matter and its potential
role as a carrier of contaminants are discussed.
Received: 28 October 1996 · Accepted: 7 July 1997 相似文献
18.
Dimitrios Sokoutis Marco Bonini Sergei Medvedev Mario Boccaletti Christopher J. Talbot Hemin Koyi 《Tectonophysics》2000,320(3-4):243-270
Orogens oblique to the direction of plate convergence are currently attributed to obliquity between the margins of one or both of the sutured continents to their direction convergence. We use a single analogue experiment and natural examples to illustrate a potential additional factor: variations in strength of the indented continent at a high angle to the convergence direction. The wavelengths of structures in laterally shortened lithosphere depend on the strength of the most competent layers. Lateral variations in crustal thickness must therefore lead to structures oblique to any applied lateral compression.
An analogue experiment was performed to explore this phenomenon. A two-layer ‘indented continent’ was modelled by a brittle upper crust of sand above a lower crust of high-viscosity polymer floating on a single layer of low-viscosity syrup representing the mantle. The well-known strike-slip structures allowing lateral escape to distant weak boundaries were hindered by lateral boundaries in front of the indenter. This allowed us to focus on the effects of a thickness change built into the ‘indented continent’ along a zone parallel to the direction in which a vertical rigid wall advancing at a steady rate represented the indenter. Vertical escape led to an ‘orogenic belt’ oblique to the advancing wall; this obliquity influences subsequent lateral escape. Model scaling and interpretations are based on Extended Thin Sheet Approximation (ETSA) and standard theories of faulting.
Four sectors of the Alpine–Himalayan orogen (Iran, Tunisia, the Eastern Alps and the Himalaya) are oblique to the continental convergence direction, and we point to thickness changes at high angles to the suture that may account for this geometry. As crustal thicknesses north of oblique sectors of the Himalayas are not yet known, we speculate on them.
We infer from the main difference between our experiment and all our examples chosen from nature that vertical orogenic escape was oblique to our model suture but can be parallel to natural sutures. 相似文献
19.
M. D. Sharma 《Journal of Earth System Science》2001,110(3):205-213
Perturbations in elastic constants and density distinguish a volume inhomogeneity from its homogeneous surroundings. The equation
of motion for the first order scattering is studied in the perturbed medium. The scattered waves are generated by the interaction
between the primary waves and the inhomogeneity. First order scattering theory is modified to include the source term generating
the primary waves. The body force equivalent to the scattering source is presented in a convenient form involving the perturbations
in wave velocities and gradient of density perturbation.
A procedure is presented to study the scattering of a spherical pulse from a small inhomogeneity, in time domain. The size
of inhomogeneity is assumed small as compared to its distance from source and receiver. No restrictions are placed on the
positions of source, receiver and inhomogeneity. The dilatation and rotations are calculated for a pulse scattered from an
arbitrary point in a spherical volume. The aggregate of the scattered phases from all the points of the inhomogeneity, reaching
at a fixed receiver, gives the amount of scattering from the inhomogeneity. The interaction of bothP andS waves with inhomogeneity are considered. Dilatation and rotations for scattering are obtained as integral expressions over
the solid angle of inhomogeneity. These expressions are computed numerically, for hypothetical models. The effects of source
(unit force) orientations, velocity and density perturbations, and size of inhomogeneity, on the scattered phases, are discussed. 相似文献
20.
We present the results of JHKLM photometry of the oxygen Mira variable V2108 Oph acquired in 2000–2004. The period of brightness variations is refined (570
± 3 days), and light and color curves in the near-IR are presented. The mean fluxes, color temperatures, and sizes for two
blackbodies representing the combined radiation of the star and dust shell at minimum and maximum brightness are estimated.
Additional IRAS data were used to compute a model with a spherically symmetric dust shell of silicate grains; the best-fit
model has a radius for its inner boundary of 2.4 × 1014 cm, a dust temperature at this boundary of 1150 K, an optical depth of the shell at 0.55 μm of 16.8, and implies a distance
to the star of 980 pc. We estimate the mass-loss rate for V2108 Oph to be 1.2 × 10−5
M
⊙/yr.
Original Russian Text ? M.B. Bogdanov, O.G. Taranova, V.I. Shenavrin, 2006, published in Astronomicheskiĭ Zhurnal, 2006, Vol.
83, No. 5, pp. 437–442. 相似文献