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891.
The climate during the past hundreds of thousands of years has been characterized by a rather distinct periodicity of about 100000 yr with brief warming periods (interglacials) lasting approximately 10000–12000 yr. Today, mankind is living in an interglacial period that began about 11 ka ago. In light of the discussion about global warming observed in recent decades, which advocates of an anthropogenic impact associate with emission of greenhouse gases due to combustion of fossil fuel, the question arises concerning the duration of the current interglacial. The data available on climate change and solar radiation on a time scale of the last millions of years are critically analyzed in this article and the problem of the length of the current interglacial is discussed.  相似文献   
892.
The rate of accretion of matter from a solar-type star onto a primordial black hole (PBH) that passes through it is calculated. The probability that a PBH is captured into an orbit around a star in a galaxy is found. The mean lifetime of the PBH in such an orbit and the rate of orbital captures of PBHs in the galaxy are calculated. It is shown that this rate does not depend on the mass of the PBH. This mechanism cannot make an appreciable contribution to the rate of observed gamma-ray bursts. The density of PBHs in the galaxy can reach a critical value—the density of the mass of dark matter in the galaxy.  相似文献   
893.
Chondrules were extracted from a disaggregated sample of the Allegan meteorite. Individual chondrules were examined with apparatus incorporating two orthogonal binocular microscopes, and their three major axes measured. Maximum chondrule diameters ranged from 0.15 to 2.75 mm with a peak in distribution between 0.35 and 0.75 mm. The chondrule size distribution was found not to conform to Rosin's law. The chondrules were found to depart from sphericity by only small amounts. The authors still believe that the melting of nebula dust-ball agglomerates by some high-energy event was the most probable mechanism for the formation of chondrules.  相似文献   
894.
Doklady Earth Sciences - Analysis of observations of the Earth’s rotational velocity and volcanic activity of the planet from 1720 until 2015 suggests that higher volcanic activity temporally...  相似文献   
895.
896.
Joseph A. Burns 《Icarus》1981,45(2):263-274
An extended photometric time series in the J and K bands of Neptune has a complex appearance which appears to require the simultaneous presence of three periodicities plus related harmonics in the (J-K) color. The most apparent of the fundamental periods is N1 = 17.73 hr. The two others are at N2 = 18.56 and N3 = 18.29 hr and may be the result of amplitude modulation of a previously reported period of 18.42 hr. We interpret the presence of multiple periodicity as indicating that distinct systems of zonal winds exist on the planet. We argue that these wind systems are probably confined to moderate or high latitudes on the basis of recent omages of the planet taken in a spectral region of strong CH4 absorption, and, by analogy to the zonal wind systems that exist in Jupiter's atmosphere, deduce a period of rotation for the body of the planet of 18.2 ± 0.4 hr. Zonal wind contrasts of up to 109 m sec?1 are implied in the atmosphere of Neptune by these observations.  相似文献   
897.
The loss rate of fast electrons (with an energy much higher than the energy of the plasma electron thermal motion), when they leave a magnetic cavern during a disturbance of the magnetic field azimuthal symmetry, is studied. The cases of point and volume sources of fast particles have been considered. The plasma density in the cavern is supposed to be low, so that collisions of fast electrons with plasma particles can be neglected. The effect of the electric field on particle motion is neglected because it is assumed that the electric charge particles outgoing from the cavern is compensated by the counter current of plasma conductivity electrons. The dependence of the loss value on the harmonic number and the amplitude of the cavern boundary radius disturbance has been obtained.  相似文献   
898.
Anthropogenic pollutants were determined in a dated sediment core, collected from a riparian wetland of the Lippe River (Ruhr district, Germany). The historical trend in heavy metals, polycyclic aromatic hydrocarbons, organochlorines, polychlorinated biphenyls and linear alkylbenzenes as well as more recent contaminants such as industrial additives, organotins, synthetic musks, methyltriclosan and some other compounds were determined for the time period between 1930 and 1986. Emission sources, information on technical production and usage, as well as on the individual pollution pathways, with appropriate environmental stability, were considered in the interpretation of the sediment contamination over the past 50 years.Contaminants were analysed and interpreted according to two different criteria: (a) the origin of the main contaminants as related to mining and industrial activities as well as municipal sewage and agricultural effluents and (b) the pollution history. Due to a significant appearance of formerly missing contaminants in sediments deposited since 1970, we suggest classifying contaminants as either common (predating 1970) or modern (postdating 1970).In summary, the study provided a comprehensive reconstruction of the pollution history of the Lippe River system.  相似文献   
899.
An analysis is made of the oil pollution of the Ob river waters using a long-term (1993–2013) hydrochemical monitoring of oil fields in Khanty-Mansi Autonomous Okrug. Contents of oil hydrocarbons (OHC) were determined in 4277 samples from the main Ob channel, and in 7076 samples from its anabranches by using infrared spectrometry. An increase in MAC (0.05 mg/dm3) was observed in 28% of the samples from the main channel, and in 32% from the anabranches. The total percentage of samples with an extremely high (> 50 MAC) and high (30–50 MAC) pollution level made up 0.3% of the samples for the anabranches, and 0.1% for the main channel. Maximum pollution was revealed in the eastern part of Okrug, from its eastern boundary to the mouth of the Trom’egan river which is associated with a considerable number of accidents on the pipelines within the Nizhnevartovskii district. The upper and lower quantiles in the most polluted anabranches, Pasl and Bagras, are 0.03–01.7 and 0.032–0.16 mg/dm3, respectively, whereas in the main Ob channel they vary from 0.022 to 0.065 mg/dm3 (0.4–1.2 MAC). The methods of geoinformatics and mathematical statistics were used to assess a dependence of OHC on the number of pollution sources (well clusters, and the area of oil spills) in zones at different distances from the river channels. By calculating the Spearman correlation coefficients, it was shown that OHC contents are dependent mainly on the number of wells, and on the area of oil spills located at less than 2 km from the channels.  相似文献   
900.
Addressing climate change requires the synergy of technological, behavioural and market mechanisms. This article proposes a policy framework that integrates the three, deploying personal carbon trading as a key element within a policy portfolio to reduce personal carbon footprints. It draws on policy and human motivation literatures that address the behavioural changes that may be needed in the context of a long-term threat such as climate change. This proposal builds on an analysis of the British Columbia carbon tax, international examples of carbon pricing instruments and strategies for behavioural change such as social networks, loyalty management, mobile apps and gamification. Interviews were conducted with experts in financial services, energy conservation and clean technology, as well as with specialists in climate, health and taxation policy. Their input, together with a review of the theoretical literature and practical case studies, informed the proposed design of a Carbon, Health and Saving System for promoting individual engagement and collective action by linking long-term climate mitigation measures with short-term personal and social goals, including health, recreation and social reinforcement.

Policy Relevance

This article identifies areas for climate policy innovation and recommends policies that can support, promote and enable personal carbon budgeting and collective action. Although this study is focused on British Columbia, both the input provided by key opinion leaders and the proposed framework are applicable to other jurisdictions.

This policy proposal shows how personal carbon trading could work in the context of a Canadian province with an existing climate mitigation policy. It also specifies a minimum viable product approach to establishing the economic, social and technological foundations for personal carbon trading.

The Carbon, Health and Saving System identifies the technologies and stakeholders needed to implement personal carbon trading, and offers the possibility of motivating a widespread conscious human response in the event that carbon taxation proves insufficient to generate economic adaptation in a changing climate.  相似文献   
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