Life Histories and Breeding Patterns of Three Intertidal Sand Beach Isopods     

AN M. C. DE Ruyck    Theodore E.  Donn Jr Anton  McLachlan 《Marine Ecology》1991,12(2):105-121

Abstract. Three-weekly transects were done over a 14-month period at Sundays River Beach, a high energy beach in Algoa Bay, South Africa, to determine the life histories, breeding patterns, and fecundities of three intertidal cirolanid isopods. Eurydice longicornis. Pontogeloides latipes , and Excirolana naialensis. E. longicornis exhibits an annual, multivoltine life history with a more extended breeding period than the other two species. P. latipes and E. natalensis both have biennial. univoltine life histories with lower fecundities than E. longicornis.  相似文献   

Effects of crude oil on the supralittoral meiofauna of a sandy beach   总被引：1，自引：0，他引：1  

Anton McLachlan  Beryl Harty 《Marine environmental research》1982,7(1):71-79

The supralittoral zone of an open sandy beach was dosed with crude oil and changes in the meiofauna monitored. Treatments included weathered and fresh oil on the surface, fresh oil mixed with dispersant on the surface and weathered oil at the water table, all in layers 0·8 cm thick. In all cases the meiofauna was reduced 1 month after dosing but numbers had returned to normal by 5 months except in the site dosed with fresh oil mixed with dispersant. Oil on the surface had greater effects than oil at the water table; fresh oil had a greater effect than weathered oil and fresh oil with dispersant was more toxic than fresh oil alone. Nematodes were least sensitive to the oil and oligochaetes more sensitive, their numbers being correlated with oil concentrations and depth in the substrate. It is concluded that, under all but the heaviest conditions of pollution in their environment, recovery from oil contamination should occur within 5 months in the meiofauna.  相似文献   

Crystal chemistry and thin film epitaxy of sulfides and Bi-Sb-sulfosalts and their geological application     

Prof. Dr. K. Bente  Prof. Dr. R. Anton 《Mineralogy and Petrology》1995,53(4):209-228

Summary Metal substitution studies of the stability, structure and chemical bonding of sulfides and sulfosalts lead to significant results, which can be applied to natural parageneses and crystal chemical systematics. Comparison of experiments on stable and metastable phases with thin films provides data, which exceed known geometrical criteria of the sulfosalt systematics. Synthetic and natural phases have been studied with respect to their substitution, bonding chemistry and temperature dependent metal distribution as well as to the structure and orientation of thin films.

---

Zusammenfassung Die Untersuchung der Stabilität, Struktur und chemischen Bindung von Sulfosalzen führt zu aussagekräftigen auf natürliche Paragenesen sowie auf die Systematik dieser Verbindungen anwendbaren Resultaten, wenn systematische Substitutionsexperimente angesetzt werden. Diese liefern im Vergleich von stabilen und metastabilen Phasen sowie durch Vergleich mit dünnen Schichten Ergebnisse, die wesentlich über bekannte strukturgeometrische Ansätze zur Sulfosalzsystematik hinausgehen. Es werden synthetische und natürliche Verbindungen bezüglich ihrer Substitution, Bindungschemie und temperaturabhängigen Metallordnung sowie die Orientierung und Struktur von dünnen Schichten diskutiert.

---

---

With 13 Figures

---

In memoriam Prof. Dr. V. Kupcik ( 1990)  相似文献   

Variable water content of nepheline from Somma-Vesuvio,Italy     

Dr. G. Balassone  Prof. Dr. A. Beran  Dr. Karl Lueger-Ring 《Mineralogy and Petrology》1995,52(1-2):75-83

Summary The water content of nephelines from volcanic, subvolcanic and metamorphic parageneses of Somma-Vesuvio, Italy was studied by polarized FTIR microspectrometry on oriented (0001) crystal plates. The H(in2)O content varies from 0.05 to 0.39 wt% and is mainly controlled by the number of vacancies in the alkali site. Most samples show an inhomogeneous distribution of the H₂O molecules, oriented with their H-H-axis perpendicular to [0001]. The absorption behaviour in the region of the OH-stretching fundamentals is characterized by four spectra types. The high temperature spectrum of a thermally treated nepheline reported by Beran and Rossman (1989) also occurs in some natural samples from the metamorphic paragenesis of Somma-Vesuvio.

---

Zusammenfassung Variabler Wassergehalt im Nephelin vom Somma-Vesuvio, Italien Der Wassergehalt von Nephelinen aus vulkanischen, subvulkanischen and metamorphen Paragenesen vom Somma-Vesuvio, Italien wurde mittels polarisierter FTIRMikrospektrometrie an orientierten (0001) Kristallplatten untersucht. Der H₂O-Gehalt variiert von 0.05 bis 0.39 Gew% and wird im wesentlichen durch die Anzahl der Leerstellen in der Alkali-Position bestimmt. Die meisten Proben zeigen eine inhomogene Verteilung der H₂O-Molekiile, deren H-H-Achse senkrecht [0001] orientiert ist. Das Absorptionsverhalten im Bereich der OH-Streckschwingungen ist durch vier Spektrentypen charakterisiert. Das vonBeran andRossman (1989) beschriebene Hochtemperatur-Spektrum eines thermisch behandelten Nephelins zeigen auch einige natürliche Proben metamorpher Paragenesen vom Somma-Vesuvio.

  相似文献   

Thermoelastic properties of chromium oxide Cr<Subscript>2</Subscript>O<Subscript>3</Subscript> (eskolaite) at high pressures and temperatures     

Anna M. Dymshits  Peter I. Dorogokupets  Igor S. Sharygin  Konstantin D. Litasov  Anton Shatskiy  Sergey V. Rashchenko  Eiji Ohtani  Akio Suzuki  Yuji Higo 《Physics and Chemistry of Minerals》2016,43(6):447-458

A new synchrotron X-ray diffraction study of chromium oxide Cr₂O₃ (eskolaite) with the corundum-type structure has been carried out in a Kawai-type multi-anvil apparatus to pressure of 15 GPa and temperatures of 1873 K. Fitting the Birch–Murnaghan equation of state (EoS) with the present data up to 15 GPa yielded: bulk modulus (K _0,T0), 206 ± 4 GPa; its pressure derivative K′_0,T , 4.4 ± 0.8; (?K _0,T /?T) = ?0.037 ± 0.006 GPa K^?1; a = 2.98 ± 0.14 × 10^?5 K^?1 and b = 0.47 ± 0.28 × 10^?8 K^?2, where α _0,T  = a + bT is the volumetric thermal expansion coefficient. The thermal expansion of Cr₂O₃ was additionally measured at the high-temperature powder diffraction experiment at ambient pressure and α _0,T0 was determined to be 2.95 × 10^?5 K^?1. The results indicate that coefficient of the thermal expansion calculated from the EoS appeared to be high-precision because it is consistent with the data obtained at 1 atm. However, our results contradict α ₀ value suggested by Rigby et al. (Brit Ceram Trans J 45:137–148, 1946) widely used in many physical and geological databases. Fitting the Mie–Grüneisen–Debye EoS with the present ambient and high-pressure data yielded the following parameters: K _0,T0 = 205 ± 3 GPa, K′_0,T  = 4.0, Grüneisen parameter (γ ₀) = 1.42 ± 0.80, q = 1.82 ± 0.56. The thermoelastic parameters indicate that Cr₂O₃ undergoes near isotropic compression at room and high temperatures up to 15 GPa. Cr₂O₃ is shown to be stable in this pressure range and adopts the corundum-type structure. Using obtained thermoelastic parameters, we calculated the reaction boundary of knorringite formation from enstatite and eskolaite. The Clapeyron slope (with \({\text{d}}P/{\text{d}}T = - 0.014\) GPa/K) was found to be consistent with experimental data.  相似文献   

Calcite and dolomite in intrusive carbonatites. I. Textural variations     

Anton R. Chakhmouradian  Ekaterina P. Reguir  Anatoly N. Zaitsev 《Mineralogy and Petrology》2016,110(2-3):333-360

  相似文献   

The Calcium Isotope Composition (δ44/40Ca) of NIST SRM 915b and NIST SRM 1486     

Alexander Heuser  Anton Eisenhauer 《Geostandards and Geoanalytical Research》2008,32(3):311-315

The calcium isotopic composition of NIST SRM 915b and 1486 provided by the National Institute of Standards and Technology was analysed. The δ^44/40Ca values of the two reference materials relative to NIST SRM 915a were: NIST SRM 915b =+0.72 ± 0.04‰ and NIST SRM 1486 =?1.01 ± 0.02‰. NIST SRM 1486 did not require any chemical separation prior to measurement.  相似文献   

Availability and coverage of hydrologic data in the US geological survey National Water Information System (NWIS) and US Environmental Protection Agency Storage and Retrieval System (STORET)     

Bora Beran  Michael Piasecki 《Earth Science Informatics》2008,1(3-4):119-129

The need for a unified and improved data access system for the nation’s vast hydrologic data holdings has increased over the past few years as researchers strive for better understanding the human impact on the nation’s water cycle. Large mission oriented data repositories such as the USGS’ National Water Information System (NWIS) and EPA’s Storage and Retrieval System (EPA STORET) play a crucial role in providing a substantial amount of the nationwide coverage, however they do differ regionally in terms of coverage (parameters) and geospatial data density. Besides the differences in geographic distribution, repositories tend to undergo changes in mission statements and as such have different foci in their data collection activities that change as time progresses. This paper places the two water information systems next to each in an attempt to work out the differences in terms of coverage and content and how they complement each other when overlaid. This is done through the use of a number the CUAHSI Hydrologic Information Systems components, namely a web-service suite called WaterOneFlow that permits interrogation of the available data content of a national water metadata catalogue into which these two information systems have been integrated.  相似文献   

Extension and inversion structures in the Tethys–Atlantic linkage zone,Algarve Basin,Portugal     

Adrià Ramos  Oscar Fernández  Pedro Terrinha  Josep Anton Muñoz 《International Journal of Earth Sciences》2016,105(5):1663-1679

  相似文献   

Design of Pressure Relief Valves for Protection of Steel-Lined Pressure Shafts and Tunnels Against Buckling During Emptying   总被引：1，自引：1，他引：0  

Anton J. Schleiss  Pedro A. Manso 《Rock Mechanics and Rock Engineering》2012,45(1):11-20

Using high-strength steels for pressure shafts and tunnel liners and taking into account significant rock mass participation allows the design of comparatively thin steel liners in hydropower projects. Nevertheless, during emptying of waterways, these steel linings may be endangered by buckling. Compared with traditional measures such as increased steel liner thickness and stiffeners, pressure relief valves are a very economical solution for protection of steel liners against critical external pressure and therefore buckling during emptying. A calculation procedure has been developed for the design of the required number and arrangement of pressure relief valves, and this has been used successfully in practice. Systematic model tests enabled the assumptions of the design method to be verified.  相似文献