Background concentrations of photochemically active trace constituents in the stratosphere and upper troposphere     

Kaplan  Lewis D. 《Pure and Applied Geophysics》1973,106(1):1341-1345

Summary High resolution absorption spectroscopy can be used for obtaining very small background concentrations or very low upper limits of trace constituents, particularly from measurements inQ-branches of fundamental vibration-rotation bands. As examples, the results of a search for NH₃ and SO₂ in the Vermande and Dionne Mont-Louis solar spectra will be reported. The relative concentration of NH₃ is very much lower above the Pyrenees than the generally accepted minimum background concentrations near sea-level.  相似文献   

Early diagenesis in a reducing fjord,Saanich Inlet,British Columbia—II. Trace element distribution in interstitial water and sediment     

B.J. Presley  Y. Kolodny  A. Nissenbaum  I.R. Kaplan 《Geochimica et cosmochimica acta》1972

Sediment and interstitial water from four cores in Saanich Inlet were analyzed for total iron, manganese, nickel, cobalt, copper, molybdenum, zinc, lithium and strontium. In addition, three separate sediment fractions were analyzed:

1.

(i) dilute acid soluble  相似文献   

Scattering of radiation within A spectral line emitted by turbulent plasma     

S. A. Kaplan  V. N. Tsytovich 《Astrophysics》1969,5(1):8-12

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Acceleration of relativistic electrons in plasma reactors and non-linear spectra of cosmic radio sources     

S. A. Kaplan  R. D. Lomadze 《Astrophysics and Space Science》1978,57(2):271-282

A second approximation to the theory of turbulent plasma reactors in connection with the problem of interpretation of the non-linear spectra of cosmic radio sources has been investigated by the authors (Kaplan and Lomadze, 1977; Lomadze, 1977). The present paper discusses the basic results received for a Compton reactor with plasma waves of phase velocities smaller than the velocity of light, as well as for the synchrotron reactor. The distortion of the distribution function of relativistic electrons caused by their diffusion from the reactor is also presented as an example.  相似文献   

Skills development in tourism: South Africa's tourism-led development strategy     

Lucy Kaplan 《GeoJournal》2004,60(3):217-227

Skills development for tourism has attracted only a limited scholarship in the developing world. In this paper the role of skills development in advancing South Africa's tourism-led development strategy is investigated. Skills development has a central role to play in ensuring the effective and sustainable transformation and development of the tourism industry in developing countries and, in the case of South Africa, in ensuring that poorer South Africans begin to benefit from this industry. It is argued that the current lack of an integrated and co-ordinated approach to tourism skills development seriously limits the potential of skills development to impact positively on tourism transformation and development in South Africa. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Characterization of concentration fluctuations of a surface plume in a neutral boundary layer     

N. Dinar  H. Kaplan  M. Kleiman 《Boundary-Layer Meteorology》1988,45(1-2):157-175

We describe a new high-resolution sampling technique which can be used to measure concentration fluctuations simultaneously at several points in space. The technique has been used to measure the probability distribution function as a function of the detector location relative to a continuous and steady source. Results are compared to previous experiments and theoretical predictions. The spectra of the concentration fluctuations are analyzed and their behaviour as a function of downwind distance from the source is described.  相似文献   

The effects of radioactive decay of uranium on elemental and isotopic ratios of Alum shale kerogen     

Jeremy Dahl  Rolf Hallberg  I.R. Kaplan 《Applied Geochemistry》1988,3(6)

The organic matter in the Alum Shale of Sweden is believed to have been affected post-depositionally by irradiation from the natural decay of U. Alum Shale kerogen H/C ratios are inversely proportional to the natural log of the U concentration, presumably as a result of the liberation of H by irradiation of the organic matter. Stable isotopic ratios of¹³C/¹²C in Alum Shale kerogen are directly proportional to the natural log of the U concentration. Experimental irradiation of Green River shale generated hydrocarbon gases 18% lighter than the parent organic matter, which demonstrates the possibility that irradiation induced generation of isotopically light gases could lower¹³C/¹²C ratios in parent organic matter. Irradiation may be a factor governing the relation between¹³C/¹²C ratios in the Alum Shales. Alum Shale O/C ratios generally increase with increasing U concentration and it is suggested that irradiation of organic matter may facilitate oxidation. The “Rock-Eval” maturity parameters “P.I.” and “Tmax” decrease with increasing U concentration. “P.I.” is presumed to decrease as a result of bitumen destruction or polymerization by irradiation.  相似文献   

Long-chain carboxylic acids in pyrolysates of Green River kerogen     

Kimitaka Kawamura  Eu Tannenbaum  B.J. Huizinga  I.R. Kaplan 《Organic Geochemistry》1986,10(4-6)

Long-chain fatty acids (C₁₀-C₃₂), as well as C₁₄-C21 isoprenoid acids (except for C₁₈), have been identified in anhydrous and hydrous pyrolyses products of Green River kerogen (200–400°C, 2–1000 hr). These kerogen-released fatty acids are characterized by a strong even/odd predominance (CPI: 4.8-10.2) with a maximum at C₁₆ followed by lesser amounts of C₁₈ and C₂₂ acids. This distribution is different from that of unbound and bound geolipids extracted from Green River shale. The unbound fatty acids show a weak even/odd predominance (CPI: 1.64) with a maximum at C₁₄, and bound fatty acids display an even/odd predominance (CPI: 2.8) with maxima at C₁₈ and C₃₀. These results suggest that fatty acids were incorporated into kerogen during sedimentation and early diagenesis and were protected from microbial and chemical changes over geological periods of time. Total quantities of fatty acids produced during heating of the kerogen ranged from 0.71 to 3.2 mg/g kerogen. Highest concentrations were obtained when kerogen was heated with water for 100 hr at 300°C. Generally, their amounts did not decrease under hydrous conditions with increase in temperature or heating time, suggesting that significant decarboxylation did not occur under the pyrolysis conditions used, although hydrocarbons were extensively generated.  相似文献   

Role of minerals in the thermal alteration of organic matter—I: Generation of gases and condensates under dry condition     

Eli Tannenbaum  Isaac R Kaplan 《Geochimica et cosmochimica acta》1985,49(12):2589-2604

Pyrolysis experiments were carried out on Monterey formation kerogen and bitumen and Green River formation kerogen (Type II and I, respectively), in the presence and absence of montmorillonite, illite and calcite at 200 and 300°C for 2–2000 hours. The pyrolysis products were identified and quantified and the results of the measurements on the gas and condensate range are reported here.A significant catalytic effect was observed for the pyrolysis of kerogen with montmorillonite, whereas small or no effects were observed with illite and calcite, respectively. Catalytic activity was evident by the production of up to five times higher C₁–C₆ hydrocarbons for kerogen with montmorillonite than for kerogen alone, and by the dominance of branched hydrocarbons in the C₄–C₆ range (up to 90% of the total amount at any single carbon number). This latter effect in the presence of montmorillonite is attributed to cracking via a carbonium-ion [carbocation] intermediate which forms on the acidic sites of the clay. No catalytic effect, however, was observed for generation of methane and C₂ hydrocarbons which form by thermal cracking. The catalysis of montmorillonite was significantly greater during pyrolysis of bitumen than for kerogen, which may point to the importance of the early formed bitumen as an intermediate in the production of low molecular weight hydrocarbons. Catalysis by minerals was also observed for the production of carbon dioxide.These results stress the importance of the mineral matrix in determining the type and amount of gases and condensates forming from the associated organic matter under thermal stress. The literature contains examples of gas distributions in the geologic column which can be accounted for by selective mineral catalysis, mainly during early stages of organic matter maturation.  相似文献   

Relativistic turbulent plasma in pulsars     

V. N. Tsytovich  S. A. Kaplan 《Astrophysics》1972,8(3):260-272

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