bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation features of radiation from x‐ray tubes with grounded cathode
Authors: Pavlinsky G. V. , Portnoy A. Yu. 
Published: August 2002

AbstractThe return of backscattered electrons to an x‐ray tube anode with a grounded cathode leads to appreciable modification of the spectral distribution of the emitted radiation. Results of calculations performed by taking into account the influence of backscattered electrons were compared with published experimental data. The comparison showed reasonably good agreement. The spectral distribution of radiation from an OEG‐75 H x‐ray tube with a grounded cathode, which is used in ARL spectrometers, was calculated. Copyright © 2002 John Wiley & Sons, Ltd.
Soft x‐ray fluorescence measurements in materials science
Authors: Kurmaev E. Z. , Moewes A. , Ederer D. L. 
Published: August 2002

AbstractA short review of applications of soft x‐ray emission spectroscopy for the study of electronic structure and chemical bonding of advanced materials is presented. It is shown that this technique is very efficient for characterizing different materials such as transition metal compounds, layered superconductors, conducting polymers, metal/polymer interfaces and ion‐implanted insulators. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray fluorescence analysis in the Russian State Agrochemical Service: an overview
Authors: Pukhovski A. V. 
Published: August 2002

AbstractThe advantages of x‐ray spectrometry in the field of rapid non‐destructive multi‐element analysis of environmental samples have been well known since the 1950s. This was a reason to include this method in the system of analytical control of the Russian State Agrochemical Service (SAS) including regional centers and the Central Research Institute of Agrochemical Service (CINAO), and similar services all over the world. The SAS was organized by the Ministry of Agriculture of the former USSR more than 30 years ago in order to control the status of agricultural soils, quality of forage, plants, fertilizers and fertilizer management. In the previous stage (1980–90), x‐ray spectrometry used all‐vacuum simultaneous spectrometers for the quality control of forages all over the USSR in terms of macro and micro (trace) elemental composition. The program was terminated in the 1990s because of the high cost of operation, slow‐operating apparatus and changes in Russia. However, the new edition of the Agricultural Ministerial Handbook with the regional distribution of mineral nutrients in plants was created owing to the results obtained. Since 1991, more adaptable and inexpensive portable instruments became available and investigations were focused on novel agroecological tasks, e.g. soil pollution with heavy metals. The adaptable and rapid method of soil analysis was evaluated and tested in an interlaboratory study organized by CINAO with the participation of Standard Committee institutes. Relatively good agreement of participant results was demonstrated and information about different kinds of uncertainties in x‐ray fluorescence soil analysis with the use of portable instruments was obtained. This method became used as a standard of the Ministry of Agriculture of the Russian Federation for the rapid analysis of soils to determine the total content of Fe, Zn, Mn, Ni, Sr, Cr and Pb in laboratory and field conditions. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray fluorescence analysis of rocks, soils and sediments
Authors: Revenko Anatoly G. 
Published: August 2002

AbstractThis paper presents results for the successful determination of trace elements in new reference samples of rocks. The absorption‐enhancement effects were preliminarily investigated theoretically for geological samples of various types. Nineteen trace elements were determined by XRF in the new reference samples applying this technique: SKD‐1 (quartz diorite), SSv‐1 (sviatonossite), BIL‐1 and BIL‐2 (Baikal sediments). In most cases good agreement was achieved between determined and certified values. The method was used for analysing 1500 carbonate sediment samples from the Siberian Platform Foldbelt. It should be noted that low concentrations of some elements are characteristic of the rocks studied and that values are not all available in CRMs. The approach presented in this paper made it possible to solve problems arising during the analysis of carbonate rocks. Copyright © 2002 John Wiley & Sons, Ltd.
Influence of heterogeneous surface morphology on analytical signal formation in total reflection x‐ray fluorescence analysis
Authors: Alov N. V. , Oskolok K. V. 
Published: August 2002

AbstractThe fundamentals of the influence of heterogeneous surface morphology on the analytical signal formation in total reflection x‐ray fluorescence (TXRF) analysis were developed. The dependence of x‐ray fluorescence line intensity on mechanisms of new phase nucleation and growth on a foreign low‐density substrate (reflector) was considered theoretically. The approaches were tested during the study of surfaces of disc glass–ceramic carbon electrodes electrochemically modified by metal deposition and co‐deposition from aqueous solutions. It was shown that TXRF could be effectively applied for the identification of nucleation and growth mechanisms of metal and alloy thin films. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray spectrometers in Russia: history of their development and present‐day status
Authors: Brytov I. A. , Mezhevich A. N. 
Published: August 2002

AbstractThe background to the development and production of x‐ray instruments in the former USSR and Russia is due to the work of a number of scientists in educational and research institutions. The development of mass‐produced instruments and their practical introduction throughout the country were made possible by the work of the Bourevestnik Research and Production Association. The present overview of x‐ray instruments mostly examines the instruments produced for a broad range of practical applications between 1964 and the present. To some degree, as a consequence of a noticeable lag in this field in the instrument industry, the developments followed the main worldwide trends. However, Soviet scientists also created a number of interesting instruments which were unique for their time and undoubtedly favoured the progress of x‐ray spectral analysis. The overview gives a brief description of the trends in the development and production of x‐ray instruments and their components (crystals, detectors) in the former USSR and Russia. It also presents a brief analysis of today's situation in this field of industry in the world and in Russia. Copyright © 2002 John Wiley & Sons, Ltd.
Application of soft x‐ray emission spectroscopy for the study of solid‐phase reactions in Si‐based interfaces
Authors: Galakhov V. R. 
Published: August 2002

AbstractThe possibilities of soft x‐ray emission spectroscopy with variation of electron excitation energy for the study of solid phase reactions in thin films were analysed. It was shown that Si L2, 3 emission spectra of high‐photon‐energy resolution are sensitive to changes in chemical states of materials, and the variation of the electron excitation energy allows to analyse depth profiles. Si L2, 3 spectra were used for the phase analysis of the Hf/(001)Si, Ir/(111)Si, (Fe + Co)/(001)Si thin films subjected to annealing and SiO2/p‐Si and SiO2/n‐Si films irradiated with high‐energy electrons. The results are compared with data obtained by means of Rutherford backscattering, electron probe microanalysis and optical ellipsometry. Copyright © 2002 John Wiley & Sons, Ltd.
Methodical peculiarities of x‐ray electron probe microanalysis as a promising method to study environmental samples
Authors: Pavlova Ludmila A. , Belozerova Olga Yu. , Paradina Ludmila Ph. 
Published: August 2002

AbstractThe use of x‐ray electron probe microanalysis (EPMA) techniques for environmental objects samples was investigated. Several ZAF and two ϕ(ρz) methods, PAP and the original bi‐exponential model of matrix corrections, were used. The EPMA calculation technique was developed for approximately spherical individual particles of snow‐contained sediments commensurate in size with the area of x‐ray generation. An analytical equation for the size correction of spherical individual particles is proposed. The technique for selecting the optimum EPMA conditions for destruction is reported. Various procedures of the sample preparation were used. Certified basalt glasses containing small amounts of strontium and barium were prepared as reference samples for EPMA. All these procedures provide satisfactory results when applied to the analysis of snow‐contained sediments, coal ash and bones of animals and fish. These samples were investigated with the aim of using them as indicators for evaluating the pollution level of the lower atmosphere and surface and ground water and for revealing pollution mechanisms. The features of EPMA were considered in all studies and the certification characteristics of the techniques were determined. Copyright © 2002 John Wiley & Sons, Ltd.
Investigation of Cr structural positions in spinel with the use of x‐ray emission spectra and cluster calculations
Authors: Vilissov V. A. , Ryzhkov M. V. , Vilissov D. V. , Moloshag V. P. 
Published: August 2002

AbstractThe electronic structure of Cr ions in tetrahedral and octahedral environment was investigated. With the use of X‐ray emission spectra and the results of cluster DV calculations of spinel the dependence between Cr—site coordination and the structure of Cr3d states is evaluated. The comparison of X‐ray emission spectra of chromium states in spinel and other compounds and complexes such as Cr2O72−, CrO42−, Cr(CO)6, Cr2O3was made. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray diffraction effects in submicron slits and channels
Authors: Ognev L. I. 
Published: August 2002

AbstractThe effects of diffraction on capture of the radiation into narrow channels between two weakly rough surfaces pressed together (‘slitless collimator’) and channeling of x‐radiation in a three‐layered structure with low atomic number thin film inside were investigated. The influence of channel shape distortion and its surface quality on the formation of the outgoing beam was investigated. A plausible explanation is given for the observed effect of abnormality of transmission through Cr/C/Cr thin‐film channels with account of periodic deformation. The calculations of the X‐ray waveguide mode attenuation in thin rough channels were compared with the results of numerical integration of the quasi‐optical equation for electrical field amplitude. Copyright © 2002 John Wiley & Sons, Ltd.
Ontology negotiation between intelligent information agents
Authors: BAILIN SIDNEY C. , TRUSZKOWSKI WALT 
Published: August 2002

This paper describes an approach to ontology negotiation between agents supporting intelligent information management. Ontologies are
declarative (data-driven) expressions of an agent's “world”: the objects, operations, facts and rules that constitute the logical space within which an agent performs. Ontology negotiation enables agents to cooperate in performing a task, even if they are based on different ontologies.Our objective is to increase the opportunities for “strange agents” – that is, agents not necessarily developed within the same framework or with the same contextual operating assumptions – to communicate in solving tasks when they encounter each other on the web. In particular, we have focused on information search
tasks.We have developed a protocol that allows agents to discover ontology conflicts and then, through incremental interpretation, clarification and explanation,
establish a common basis for communicating with each other. We have implemented this protocol in a set of Java classes that can be added to a variety of agents, irrespective
of their underlying ontological assumptions. We have demonstrated the use of the protocol, through this implementation, in a test-bed that includes two large scientific archives: NASA's Global Change Master Directory and NOAA's Wind and Sea Index.This paper presents an overview of different methods for resolving ontology mismatches and motivates the Ontology Negotiation Protocol (ONP) as a method that addresses some
problems with other approaches. Much remains to be done. The protocol must be tested in larger and less familiar contexts (for example, numerous archives that have not been preselected) and it must be extended to accommodate additional forms of clarification and ontology evolution.
The use of breeding dens and kitten development in the Iberian lynx (Lynx pardinus)
Authors: Fernández Néstor , Palomares Francisco , Delibes Miguel 
Published: August 2002

AbstractThe use of breeding dens and the early kitten development was studied in a free‐ranging population of Iberian lynx Lynx pardinus. Radio‐tracking of female lynx allowed intensive monitoring of three litters during 1997, and additional data to be obtained from nine other litters in the previous 4 years. Females gave birth a maximum of one litter per year in spring; nine of the 10 births were recorded between the last 2 weeks of March and the first days of April. Kittens were born semi‐altricial and reared for nearly 20 days in secluded hollow trunks. Afterwards, they were moved between different bushes, which served as auxiliary dens, where they began to develop walking and senses. Kittens first consumed meat at the age of 4 weeks, although they were not fully weaned until they were at least 10 weeks old. At the age of 2 months, kittens began to leave the dens, accompanying their mothers on outings. It is suggested that the pattern of den use was related to the stage of kitten development, to fulfil the kittens' need for both protection and space as they grew. Data on kitten denning and development should be accounted for in in‐situ and ex‐situ conservation programmes for this endangered felid.
The oldest reptile in amber: a 120 million year old lizard from Lebanon
Authors: Arnold E. N. , Azar D. , Ineich I. , Nel A. 
Published: August 2002

AbstractAnimals enclosed in amber often provide a unique insight into their surface structure. Such fossils of reptiles are rare and usually not extremely ancient, the earliest being no more than 40 million years (my). A recently discovered 120 my lizard from the Lower Cretaceous of Lebanon provides direct evidence that several common external features of autarchoglossan lizards had evolved by this time. Ecomorphology indicates that the lizard concerned had considerable climbing ability on open surfaces and perhaps in vegetation, and probably lived in a mesic forested environment, something supported by associated plant and invertebrate remains.
The biology and functional morphology of Humphreyia strangei (Bivalvia: Anomalodesmata: Clavagellidae): an Australian cemented ‘watering pot’ shell
Authors: Morton Brian 
Published: August 2002

AbstractAmongst the watering pot shells of the Clavagellidae (Anomalodesmata), the least well known is Humphreyia, with a single species H. strangei. Unlike representatives of the other extant clavagellid genera, i.e. Clavagella and Brechites, however, where juveniles are unknown, there is a single juvenile (plus adult specimens) of H. strangei available for study. The Clavagellidae contains the weirdest of all bivalves, encased in a huge (in proportion to the tiny juvenile shell) adventitious tube with an anterior ‘watering pot’. The juvenile H. strangei is dimyarian with a large foot and byssal groove, and a large pedal gape; the entire body is enclosed within a bag‐like periostracum‐covered mantle cavity. Upon permanent residence, however, the anterior watering pot component of the adventitious tube is cemented to the chosen substratum, the adductor muscles are lost and the foot and pedal gape greatly reduced; the fourth pallial aperture closes and the pedal gape and the tubules of the watering pot are similarly occluded. Once cementation is achieved, further growth anteriorly is impossible and the adventitious tube is secreted posteriorly, to house the long siphons, and subsequently can be added to as growth increments. Anatomically, H. strangei has a typical anomalodesmatan arrangement of mantle cavity and digestive organs so that it is, probably, a suspension feeder. Inside the pericardium, however, is a pair of unique proprioreceptors which probably serve to monitor rectal tonus and thus control defecation, co‐ordinated with siphonal retraction and extension. They probably also prevent over‐filling of the capacious rectum. It is believed that cementation and adventitious tube formation occur at the time of sexual maturity and this change in lifestyle between juvenile and adult represents a form of metamorphosis – quite distinct from that which occurs in all bivalves between the pediveliger and juvenile stages – and seems to be unique to Humphreyia and probably Brechites. This family of anomalodesmatan bivalves is thus actually stranger than the already aberrant watering pot would suggest.
Population subdivision among mouflon sheep (Ovis gmelini) ewes and ranging behaviour of rams during the rut
Authors: Martins Ana Gonçalves , Netto Newton Tércio , Aulagnier Stéphane , Borges Ana , Dubois Michel , Vicente Luis , Gerard Jean‐François , Maublanc Marie‐Line 
Published: August 2002

AbstractPopulation subdivision among mouflon sheep Ovis gmelini ewes and ranging behaviour of rams were investigated in the Caroux‐Espinouse massif (southern France). Radio‐tracking data from 32 ewes and 41 rams monitored in the course of a 10‐year study were used to identify female units and to document the movement patterns of males during the rutting period. Cluster analyses, based on the distance between arithmetic centres and on the degree of overlap of locations, were computed. Ewes were found to be partitioned in three or four main units to which they were faithful. Movement patterns of rams were much more variable: half were faithful to a rutting range, overlapping one or more unit(s), and the others were not. We suggest that a combination of social and spatial attachment could explain this ranging behaviour. Females build up their spatial habits following their mothers and, when adults, they occupy the area where they have been reared. Their spatial attachment is consistent with their social preferences for other females. Males balance between antagonistic spatial attachment and social preferences for other males, and differ in terms of spatial behaviour. The genetic implications are discussed.
Cautionary comments on the measurement of maximum locomotor capabilities
Authors: Losos Jonathan B. , Creer Douglas A. , Schulte James A. 
Published: August 2002

AbstractIn recent years, laboratory measurements of locomotor performance of small organisms have been used increasingly to study questions in behavioural, physiological, and evolutionary ecology. Although a valuable tool that can provide insight into organismal function, behaviour, and adaptation, this approach is potentially limited by the quality of the data collected. Using the study of maximum sprint speed in lizards as an example, common problems in methodology that may confound interpretation of performance studies are discussed.
Reproductive ecology of a tropical natricine snake, Tropidonophis mairii (Colubridae)
Authors: Brown Gregory P. , Shine Richard 
Published: August 2002

AbstractAlthough most snake species are tropical, very little is known about their biology. We monitored reproductive histories of individually marked natricine colubrid snakes (keelbacks, Tropidonophis mairii) for 18‐months in a tropical Australian floodplain. Our data provide the first unambiguous records (for any snake species) of individual females in a natural population producing multiple clutches of eggs during a single breeding season. The snakes bred throughout drier months of the year. The mean size of reproducing females decreased over the season, whereas relative clutch mass increased significantly over the same time period. Larger females produced eggs that were not only larger, but also shorter and wider, than those of smaller females. Despite producing two clutches in short succession, female keelbacks grew over the intervening period. Thus, they switch from ‘capital breeding’ (building up stores of energy during the wet season to use for reproduction in the dry season) to ‘income breeding’ (relying on recently ingested energy to support both growth and reproduction during the dry season). Two females marked at hatching were recaptured as breeding adults <12 months later, confirming that maturation is attained more rapidly in this species than in temperate‐zone natricines.
Identification of twenty‐two bat species (Mammalia: Chiroptera) from Italy by analysis of time‐expanded recordings of echolocation calls
Authors: Russo Danilo , Jones Gareth 
Published: August 2002

AbstractSpectral and temporal features of echolocation calls emitted by 22 bat species from Italy (three rhinolophids, 18 vespertilionids and the molossid Tadarida teniotis) are described. Time‐expanded recordings of calls from 950 bats of known identity were examined. Rhinolophus ferrumequinum, R. hipposideros, R. euryale and T. teniotis could be identified by measuring the call frequency of highest energy (FMAXE). Quadratic discriminant function analysis with cross‐validation was applied to calls from the remaining 18 species. A function based on start frequency (SF), end frequency (EF), FMAXE and duration (D) provided a correct overall classification of approximately 82%. A classification model at genus level that also comprised middle frequency (MF) and inter‐pulse interval (IPI) reached 94% correct classification. Two separate discriminant functions were devised for species emitting FM (frequency modulated) and FM/QCF calls (i.e. calls consisting of a frequency‐modulated component followed by a terminal part whose frequency is almost constant) respectively. The former function included SF, EF, FMAXE and D and provided an overall classification rate of 71%; the latter comprised EF, MF, D and IPI, and reached 96%. The functions may be applied to bat habitat surveys in southern Italy since they cover most of the species occurring in the area.