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31.
Katarina Hansson-Forman Elsa Reimerson Annelie Sjölander-Lindqvist Camilla Sandström 《社会与自然资源》2018,31(7):837-852
The governance of large carnivores is often surrounded by conflicts. Along with the difficulties of governing large carnivores through centralized, top-down governing and a general shift towards participatory approaches in natural resource governance, this has led many countries to establish various collaborative measures in large carnivore governance – often presented as a catch-all solution to problems of legitimacy, democratic deficit and effectiveness. However, the field of large carnivore governance currently lacks a coherent understanding of strengths and weaknesses of different kinds of collaborative arrangements. In this paper, we address this knowledge gap. Using the framework of modes of governance to categorize and compare the governance of large carnivores in Norway, Sweden and Finland, we discuss the potential and limitations of various governance modes and identify gaps in contemporary research literature. The main conclusion is that all three governance systems need to incorporate more interactive governance elements. 相似文献
32.
The addition of synthetic additives, such as methanol and methyl tertiary butyl ether (MTBE) to the base fuel, with the aim of raising the octane content of motor fuel, is currently of special interest in Sweden. A question, which has to be solved, is whether it is preferable to carry the additives by ship in separate tanks, because of the probable enhanced toxicity of the motor fuels by the addition of solvents, or not. The acute toxicity of these blend fuels has been compared with the acute toxicity of base fuel, gasoline and low leaded gasoline. As test organisms, two representative species of the Baltic Sea have been used, the harpacticoid Nitocra spinipes and the bleak, Alburnus alburnus. The results of the tests show that the acute toxicity of base fuel to aquatic organisms is not increased by the addition of 15% methanol or 5% MTBE. 相似文献
33.
This paper analyzes the environmental conflict concerning the construction of a permanent link between Malmo, Sweden and the Danish capital, Copenhagen. The conflict is approached as both a discursive and institutional struggle, in which representations of nature and the environment are used not only to legitimize, but also to question institutional policies and development plans. The analysis focuses primarily on three of the counter-discourses that have emerged in conflict with the hegemonic, institutional discourse, and also indicates how spatial representations have become important constituents of the discourses. 相似文献
34.
Henrik Lundstedt Anders Johannesson Göran Scharmer Jan Olof Stenflo Ulf Kusoffsky Birgitta Larsson 《Solar physics》1991,132(2):233-245
A high-resolution videomagnetograph that records the images of opposite circular polarization simultaneously has been constructed for the Swedish vacuum solar telescope at La Palma. Magnetograms are obtained by off-line integration of bursts consisting of typically 50 frames of 20 ms exposures, with bad frames rejected, and the frame-to-frame image motion of the remaining frames compensated for by cross-correlation techniques. The short exposures combined with frame selection and elimination of image motion optimizes the resolution and thereby also the S/N, allowing good magnetograms to be obtained with an effective exposure time of less than 1 s at an image scale of 0.1 pixel–1. The advantages and limitations of the system are discussed and compared with other techniques of making filter magnetograms are discussed. 相似文献
35.
Jan Olof Stenflo 《Solar physics》1969,8(2):260-263
The polarization of a normal Zeeman triplet is discussed for the case in which the lifetime of the excited state of the atom is comparable to or shorter than the period of Larmor precession. 相似文献
36.
The northern Norrbotten area in northern Sweden, is an important mining district and hosts several deposits of Fe-oxide Cu-Au-type. One of the best examples of spatially, and possibly genetically, related apatite–iron and copper–gold deposits in the region is at Tjårrojåkka, 50 km WSW of Kiruna. The deposits are hosted by strongly sheared and metamorphosed intermediate volcanic rocks and dolerites and show a structural control. The Tjårrojåkka iron deposit is a typical apatite–iron ore of Kiruna-type and the Tjårrojåkka copper occurrence shows the same characteristics as most other epigenetic deposits in Norrbotten. The host rock has been affected by strong albite and K-feldspar alteration related to mineralisation, resulting in an enrichment of Na, K, and Ba. Fe and V were depleted in the altered zones and added in mineralised samples. REE were enriched in the system, with the greatest addition related to mineralisation. Y was also mobile associated with albite alteration and copper mineralisation. The Tjårrojåkka iron and copper deposits show comparable hydrothermal alteration minerals and paragenesis, which might be a product of common host rock and similarities in ore fluid composition, or overprinting by successive alteration stages. Mineralogy and mineral chemistry of the alteration minerals (apatite, scapolite, feldspars, amphiboles, and biotite) indicate a higher salinity and Ba/K ratio in the fluid related to the alterations in the apatite–iron occurrence than in the copper deposit, where the minerals are enriched in F and S. The presence of hematite, barite, and in SO4 in scapolite suggests more oxidising-rich conditions during the emplacement of the Tjårrojåkka-Cu deposit. From existing data it might be suggested that one evolving system created the two occurrences, with the copper mineralisation representing a slightly later product. 相似文献
37.
Per Olof Lindblad 《Astronomy and Astrophysics Review》1999,9(3-4):221-271
Summary. The aim of the present review is to give a global picture of the supergiant barred galaxy NGC 1365. This galaxy with its
strong bar and prominent spiral structure displays a variety of nuclear activity and ongoing star formation.
The kinematics of the galaxy has been mapped in detail by optical long slit and Fabry–Perot observations as well as radio
observations of Hi and CO interstellar lines. From these observations a combined velocity field has been derived, describing the circulation
of interstellar gas in the symmetry plane of the galaxy. With a gravitational potential based on near infrared photometry
of the bar and the shape of the apparent rotation curve, computer simulations of the dynamics of the interstellar gas have
been made with the aim to reproduce both the morphology of the interstellar matter as well as the observed velocity field.
The simulations demonstrate the role of the bar and the importance of resonances between the bar rotation and the rotation
of the galaxy for the formation of the spiral structure. Polarization of radio radiation reveals magnetic fields concentrated
to the dust lanes along and across the bar, where they are aligned with the flow pattern of the gas, and along the spiral
arms. The kinematics of the outer region of the galaxy with a fairly unique decline of the rotation curve leads to the conclusion
that NGC 1365 lacks a very massive dark matter halo, which may permit the formation of a very strong bar.
The galaxy contains an active nucleus with both broad and narrow components of the permitted spectral emission lines. The
nucleus is surrounded by a molecular torus, numerous star forming regions and continuum radio sources. The star forming regions
are, as seen with the Hubble Space Telescope (HST), resolved into a large number of super star clusters suggested to be young
globular clusters. A very compact radio source, seen at high spatial resolution with the Very Large Array (VLA), has been
claimed to coincide with one of the super star clusters. This compact source has a radio brightness of the order of 100 times
that of the bright galactic supernova remnant Cas A and is suggested to be a so called ‘radio supernova’. Two other such compact
radio sources, positioned in the prominent dark dust lane penetrating the nuclear region, are identified as strong infrared
sources by observations with the Very Large Telescope (VLT). The cause of this infrared radiation may be dust heated by the
objects that drive the radio sources.
The X-ray radiation from the nucleus is interpreted to consist of hard continuum radiation from the active nucleus itself,
Fe-K line emission from a rotating disk, and thermal emission from the surrounding star burst activity. A secondary, highly
variable source has been discovered close to the nuclear region. It seems to be one of the most luminous and most highly variable
off-nuclear X-ray sources known.
The higher excitation optical emission lines in the nuclear region, primarily from [Oiii], reveal a velocity field quite different from that described by the galactic rotation. The deviating [Oiii] morphology and velocity field in the nuclear region is interpreted in terms of a high excitation outflow double-cone with
its apex at the nucleus and symmetry axis perpendicular to the symmetry plane of the galaxy. One of the circumnuclear radio
sources seems to be a one-sided jet emerging from the nucleus aligned with the cone axis. According to the model, the outward
flow within the cone is accelerated and the flow velocity highest at the cone axis.
Received 15 January 1999 相似文献