Zur Kenntnis der Kalkinkrustation und Kalkkorrosion im Seelitoral     

Stjepko Golubić 《Aquatic Sciences - Research Across Boundaries》1962,24(2):229-243

Ohne Zusammenfassung  相似文献   

The influence of raw domestic sewage on density and distribution of meiofauna     

Jasna Vidaković 《Marine pollution bulletin》1983,14(3):84-88

The influence of raw domestic sewage on density and distribution of meiofauna in the sea bottom sediments in the Northern Adriatic Sea, in the area of Rovinj (Yugoslavia), was investigated, comparing meiofaunal density at the stations which are under direct influence of sewage and the stations which are far from the source of pollution. It is concluded that raw domestic sewage does not have a negative influence on the density and distribution of meiofauna, but Parker's index of pollution indicates that meiofauna at these stations were under stress.  相似文献   

Croatia in the continental traffic network of Europe     

Adolf Malić  Damir Bozičević 《GeoJournal》1996,38(4):463-468

Croatia is located on the southeastern edge of Central Europe (Ruppert 1995), between the navigable Danube River and the Adriatic Sea, so that participates not only in continental traffic, but in the maritime and river traffic of Europe as well.Although the transit position of Croatia is very favorable, transportation itself has unfortunately not been developed in accordance with these advantages. This is a result of the social-economic, especially political, development of the region in the course of its history. Unfortunately, politics also influences the selection of transit routes in this part of Europe today. With the break-up of socialist states, particularly the former Yugoslavia, new states have appeared which are seeking their place in the European traffic network. Because of the momentarily uncertain political circumstances, the construction of some transit routes in Croatia have not been foreseen in international developmental plans for continental transit, despite the fact that they would be logically expected given the advantages of their position.  相似文献   

Automatic time recording in determination of astronomical latitude and longitude using an astrolabe and an HP41CX     

Nikola Solarić 《Astrophysics and Space Science》1991,177(1-2):169-173

The paper presents the automatic time recording of transits of the image of a star across the hairs in the visual field of a telescope and the automatic reception of radio time signals for the determination of astronomical latitude and longitude of a station using an astrolabe. The automatization was achieved by an electronic calculator Hewlett Packard HP41CX and an especially constructed relay. The method proved very practical in the course of making the network of geoidal points more dense for the needs of geodesy.  相似文献   

The two polymorphs of TlPbSbS3 and the structural relations of phases in the system TlSbS2-PbS     

Dr. T. Balić Zunić  Prof Dr. K. Bente 《Mineralogy and Petrology》1995,53(4):265-276

Summary The synthetic TlPbSbS₃ represents a rare example of a sulphosalt with statistical distribution of Tl, Pb and Sb in the structure. Within the TlSbS₂-PbS system, TlPbSbS₃ is the end member of the solid solution series with TlSbS₂, but no solubility with PbS is detected. The high temperature-TlPbSbS₃ is orthorhombic and inverts at about 620 K to the low-temperature phase. The low-temperature modification of TlPbSbS₃ was structurally investigated by X-ray powder diffraction and by the Rietveld analysis of the data. The structure is monoclinic, with a = 4.1707(4) Å, b = 4.2856(4) Å, c = 12.157(1) Å, = 105.49(1)°, space group P2₁/c. Like in the high-temperature form, there is a cation disorder over the equivalent positions in the structure. The interatomic distances of (Tl, Ph, Sb) to S are 2.71, 2.72, 2.88, 3.15, 3.29, 3.51 (Å). There is a close similarity between the TlPbSbS₃ polymorphs and the and forms of SnS, as regards the atomic coordinations and the general structure types and the same type of phase transformation is supposed for both cases. The small differences in the structure type and symmetry, between the low temperature forms of SnS and TlPbSbS₃, result probably from stronger metal-metal interactions in the latter. A substitution-derivative relation to SnS type is established owing to the strong structural effect of the lone electron pairs of Tl and Sb. The substitution of Ag for Tl and Bi for Sb in ABCS₃ type compounds diminishes this effect and PbS type structures are produced.

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Die zwei Polymorphen von TlPbSbS₃ und die Strukturellen Beziehungen von Phasen in System TlSbS₂-PbS

Zusammenfassung Die synthetische Phase TlPbSbS₃ ist ein seltenes Beispiel von einem Sulfosalz mit der statistischen Verteilung von TI, Pb und Sb in der Struktur. In der TlSbS2-PbS Phasensystem, ist TlPbSbS₃ das Endmitglied der Mischkristallreihe, die sich im Richtung TlSbS₂ ausstreckt. Weitere Ausdehnung der Mischkristallreihe in der Richtung SbS konnte nicht bewiesen werden. Die Hochtemperatur-TlPbSbS₃ ist rhombisch und wird beim 620 K in die Tieftemperatur Modifikation umgewandelt. Die Tieftemperaturphase ist mit der Röntgenpulverdiffraktion und Rietveld Methode strukturell untersucht worden. Die ist monoklin, mit den Gitterkonstanten: a = 4.1707(4) Å, b = 4.2856(4) Å, c = 12.157(1) Å, = 105.49(1)°, Raumgruppe P2₁/c. Die statistische Verteilung von Kationen ist auch hier vorhanden. Die zwischenatomare Abstande (Tl, Pb, Sb)-S sind: 2.71, 2.72, 2.88, 3.14, 3.28, 3.51 (Å). Es besteht eine enge Verwandschaft zwischen den polymorphen Modifikationen von TlPbSbS₃ und den und Polymorphen von SnS, was die atomare Koordinationen und den generellen Strukturtypus betrifft, wobei ein ähnlicher Mechanismus der Phasenumwandlung für die beiden Fälle vermutet werden könnte. Die Differenzen in der Struktur und Symmetrie zwischen der Tieftemperaturmodifikationen von SnS und TlPbSbS₃ sind wahrscheinlich durch die bedeutende Metall-Metall Wirkungen in der zweiten verursacht. Die Phase TlPbSbS₃ ist ein substitution-derivative von der SnS Struktur, was durch die starke lone-electron-pair Aktivität von Kationen zu erklären ist. Die Ersetzung von Tl durch Ag und Sb durch Bi vermindert diese Aktivität und die entstandenen Strukturen sind in dem Fall dem PbS-Typus verwandt.

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With 3 Figures  相似文献   

Jankovićite,Tl5Sb9(As,Sb)4S22, a new TI-sulfosalt from Allchar,Macedonia     

Lj. Cvetković  V. A. Boronikhin  M. K. Pavićević  D. Krajnović  I. Gržetić  E. Libowitzky  G. Giester  E. Tillmanns 《Mineralogy and Petrology》1995,53(1-3):125-131

Summary A hitherto unknown TI-sulfosalt, containing antimony and arsenic, was discovered by ore microscopy (including quantitative reflectance measurements) and electron microprobe analysis in samples from the Allchar TI-Sb-As sulfide ore deposit (Macedonia). The chemical formula is TI₅Sb₉(As,Sb)₄S₂₂, X-ray single crystal and powder diffration data gave the lattice parameters _o = 7.393(4) Å, b₀ = 8.707(2) Å, c_o = 17.584(3) Å, = 103.81(1)°, = 91.79(1)°, = 109.50(1)°; space group , Z = 1. The new mineral and the new mineral naine jankoviéite have been approved by the IMA/CNMMN.

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Jankoviit, Tl₅Sb₉(As,Sb)₄S₂₂, ein neues TI-Sulfosalz aus Allehar, Macedonien

Zusammenfassung Ein bislang unbekanntes Thallium-Antimon-Arsen-Sulfosalz wurde mittels Erzmikroskopie (inklusive quantitativer Reflexionsmessungen) und Elektronenstrahl-Mikrosonde in Proben aus der TI-Sb-As-Sulfid-Lagerstätte Allchar in Macedonien entdeckt. Die chemische Formel lautet Tl₅Sb₉(As,Sb)₄S₂₂, aus Röntgen-Einkristallaufnahmen und Pulverdiffraktogrammen konnten folgende Gitterkonstanten bestimmt werden: a_o = 7.393(4) Å, b_o = 8.707(2) _Å, c_o = 17.584(3) Å, a = 103.81(1)°, = 91.79(1)°, = 109.50(1)°; Raumgruppe , Z = 1. Das neue Mineral, sowie der neue Mineralname Jankoviit wurden durch die IMA/CNMMN anerkannt.

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Surfactant production by marine phytoplankton     

Vera Ẑutić  Boẑena Ćosović  Elena Marčenko  Nevenka Bihari  Frano Kršinić 《Marine Chemistry》1981,10(6):505-520

Electrochemical methods based on adsorption of organic molecules at the mercury electrode-solution interface were used to investigate surfactant production by marine phytoplankton. Six species of marine phytoplankton, representing the classes of Bacillariophyceae, Haeptophyceae, Chlorophyceae and Cryptophyceae, were studied in batch cultures.Our experimental results showed that surfactants were produced in culture media by healthy exponential growing cells. The measured response was found to depend on the particular species and the age of the culture.Total surfactant content in culture media generally increased with cell density, while surfactants per cell showed an inverse relation to cell density. However, we found that in Cryptomonas culture medium, during the exponential growth, excretion of the insoluble surfactant material per cell was independent of cell concentration.In addition to culture experiments, surfactant activity at several northern Adriatic stations was measured during various stages of phytoplankton bloom. It was concluded that a significant part of surfactant activity in a seawater column is due to phytoplankton production.  相似文献   

Distribution of mercury and methylmercury in deep-sea surficial sediments of the Mediterranean Sea     

Nives Ogrinc  Mathilde Monperrus  Jože Kotnik  Vesna Fajon  Klara Vidimova  David Amouroux  David Kocman  Emmanuel Tessier  Suzana Žižek  Milena Horvat 《Marine Chemistry》2007

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Atmospherical effects of the total solar eclipse in 1961     

Dipl.-Met. Bratislav Anić 《Theoretical and Applied Climatology》1970,18(2):197-201

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Management of karst aquifers in Serbia for water supply     

Zoran Stevanović  Igor Jemcov  Saša Milanović 《Environmental Geology》2007,51(5):743-748

Karst aquifers represent one of the main sources of water supply in Serbia. Wide distributions of karstic areas, abundant reserves, and excellent quality of karst groundwater have been the reasons for its extensive use in water supply systems throughout the country. In Serbia, 70 karstic sources have been tapped for centralized water supply, with the assessed minimal capacity exceeding 4.5 m³/s. Most of the large cities of Eastern and Western Serbia currently use karst groundwater for water supply; however, due to unstable flow regime when only natural springflow is tapped, numerous problems arise during the recession period (summer–autumn). During the last two decades, after favorable conditions had been confirmed through hydrogeological survey and feasibility studies, several newly constructed systems for artificial control of karst aquifers (mostly in Eastern Serbia) resulted in significantly improved water supply.  相似文献