Reproduction in the Herpetofaunal Community of a Banksia Woodland Near Perth, W.a.

1980 ◽  
Vol 28 (3) ◽  
pp. 435 ◽  
Author(s):  
C Davidge
Keyword(s):  
Surface Water ◽  
High Frequency ◽  
Early Summer ◽  
The Other ◽  
Reproductive Pattern ◽  
Very High Frequency ◽  
The Third ◽  
Frog Species ◽  
Second Year ◽  
Very High

Twelve species of lizards (Agamidae, Scincidae, Pygopodidae) and three species of frogs (Leptodac- tylidae) comprise the herpetofaunal community of a Banksia woodland under a mediterranean-type climate in Western Australia. The reptiles bred in September-November and laid eggs in early summer. The requirement of surface water for tadpole development for two of the frog species restricted their breeding time to winter and necessitated their migration from the study area, where no water was avail- able. The third species of frog, Myobatrachus gouldii, lacks an aquatic stage. Its reproductive pattern coincided with neither that of the reptiles nor the other frogs. Collections of most species in the com- munity were not equally divided between sexes. For reptiles, this possibly was owing to differential trapping of the sexes. The very high frequency of capture of female frogs, other than those of M. gouldii, was probably related to differential dispersal of the sexes from breeding areas. The distribution of the percentage frequency of snout-vent lengths for six species of lizards suggests that individuals did not breed until their second year.

LONG DURATION ECHOES FROM AURORA, METEORS, AND IONOSPHERIC BACK-SCATTER

1953 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
D. W. R. McKinley ◽  
Peter M. Millman
Keyword(s):  
Long Range ◽  
High Frequency ◽  
The Other ◽  
Very High Frequency ◽  
Long Duration ◽  
E Region ◽  
Very High ◽  
Visual Observations

In the course of the Ottawa meteor program some unusual echoes have been detected on 33 Mc. Echoes from the aurora are discussed and correlated with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here presented are insufficient to favor one over the other. On Aug. 4, 1948, six extremely long duration meteor echoes were observed which may have been due to abnormal ionospheric conditions. From time to time since August, 1948, a weak semipermanent echo has been recorded, usually appearing at a range of about 80 km., and enduring up to an hour. It is suggested that this echo is due to back-scatter from the same sources in the lower E-region that are presumed to be responsible for long-range very high frequency propagation.

scholarly journals Skipping of the very-high-frequency structural particle de (的) in Chinese reading

2018 ◽  
Vol 71 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Chuanli Zang ◽  
Manman Zhang ◽  
Xuejun Bai ◽  
Guoli Yan ◽  
Bernhard Angele ◽  
...  
Keyword(s):  
Experimental Psychology ◽  
High Frequency ◽  
The Other ◽  
Chinese Reading ◽  
Very High Frequency ◽  
Sentential Context ◽  
Parafoveal Preview ◽  
Single Character ◽  
Boundary Paradigm ◽  
Very High

How do readers decide whether to skip or fixate a word? Angele and Rayner [2013. Processing the in the parafovea: Are articles skipped automatically? Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 649–662] showed that English readers base skipping decisions on the parafoveal information available, but not the sentential context. Due to the increased visual density of the language, Chinese readers may be able to process a parafoveal word and integrate it with the sentence context to a greater extent than English readers. Consequently, influences on skipping decisions in Chinese may differ from those in English. In a boundary paradigm experiment, participants read sentences containing a single-character target verb (e.g., 取 meaning get) whose preview was manipulated in three conditions: identity preview; a preview consisting of the syntactically anomalous high-frequency structural particle de (的), or a pseudocharacter preview. The results showed that Chinese readers were more likely to skip the target when the preview was de than in either of the other conditions, suggesting that de-skipping is triggered by the parafoveal preview of a highly frequent particle word rather than on the likelihood of the upcoming word given the sentential context.

scholarly journals The hyperfine structure of the lines of the arc spectrum of rubidium

1933 ◽  
Vol 139 (839) ◽  
pp. 673-682 ◽  
Keyword(s):  
Fine Structure ◽  
High Frequency ◽  
The Other ◽  
Resolving Power ◽  
Nuclear Moment ◽  
Very High Frequency ◽  
Centre Of Gravity ◽  
Helium Neon ◽  
Very High ◽  
Echelon Grating

The structure of the lines of the arc spectrum of rubidium was investigated with a reflexion echelon grating of high resolving power, the light source being a tube containing helium neon mixture at about ½ mm. pressure and a small quantity of rubidium; this tube was fitted with external electrodes and excited with an oscillator of very high frequency. The two resonance lines—7947 and 7800—were found to possess the same fine structure, and each possessed four components: at 0·00, —0·09, —0·19 and —0·23 cm. -1 ; the two outer components, 0·00 and —0·23 cm. -1 , are weak and the two inner components are strong. The lines 4215 and 4201 were found to possess three components; at 0·00, —0·09 and —0·20 cm. -1 . The line at the latter point was slightly broadened. This was presumed to correspond to the same structure as that observed in the resonance lines, the broadened line corresponding to —0·19 and —0·23 unresolved. This observed structure is explained as arising from the 5S 1/2 level; the two outer, weak, components arising from the isotope 87 and corresponding to a separation into two levels, 0·23 cm. -1 apart, in the 5S 1/2 level; while the two inner, stronger, components arise from the other isotope, 85, and correspond to a similar separation of 0·10 cm. -1 . The centre of gravity of the levels of Rb 85 is displaced about 0·02 cm. -1 from that of the levels of Rb 87. Measurements on the intensities of the components of 4201 show that the probable value for the nuclear moment of Rb 85 is 3/2, but the accuracy is not sufficiently high to enable the value for the scarcer isotope Rb 87 to be determined with certainty; the probable value is, however, 5/2. The magnetic moment of the nucleus of Rb 87 is shown to be approximately two and a half times as great as that of Rb 85.

Experimental Investigation of very High Frequency Slot Antenna on M-60A-1 Tank

1977 ◽  
Author(s):  
D. V. Campbell ◽  
William Kennebeck ◽  
A. Zanella ◽  
Paul Sexton
Keyword(s):  
Experimental Investigation ◽  
High Frequency ◽  
Slot Antenna ◽  
Very High Frequency ◽  
Very High

A collision feedback based multiple access control protocol for very high frequency data exchange system in E-navigation

2021 ◽  
pp. 1-16
Author(s):  
Xu Hu ◽  
Bin Lin ◽  
Ping Wang ◽  
Hongguang Lyu ◽  
Tie-Shan Li
Keyword(s):  
Access Control ◽  
High Frequency ◽  
Multiple Access ◽  
Data Exchange ◽  
High Frequency Data ◽  
Frequency Data ◽  
Exchange System ◽  
Very High Frequency ◽  
Time Division ◽  
Very High

Abstract The very high frequency data exchange system (VDES) is promising in promoting electronic navigation (E-navigation) and improving navigation safety. The multiple access control (MAC) protocol is crucial to the transmission performance of VDES. The self-organising time division multiple access (SOTDMA) protocol, as the only access mode given by current recommendations, leads to a high rate of transmission collisions in the traditional automatic identification system (AIS), especially with heavy traffic loads. This paper proposes a novel feedback based time division multiple access (FBTDMA) protocol to address the problems caused by SOTDMA, such that collision of transmissions can be avoided in information transmission among vessels. Simulation results demonstrate that the proposed FBTDMA outperforms the traditional SOTDMA in terms of channel utilisation and throughput, and significantly reduces the transmission collision rate. The study is expected to provide insights into VDES standardisation and E-navigation modernisation.

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

Da eine oder mehrere betroffen …

2020 ◽  
Vol 48 (1) ◽  
pp. 47-100
Author(s):  
Melitta Gillmann
Keyword(s):  
High Frequency ◽  
Formal Language ◽  
Subordinate Clause ◽  
Matrix Clause ◽  
Very High Frequency ◽  
Corpus Study ◽  
Causal Relations ◽  
Legal Texts ◽  
The Matrix ◽  
Very High

AbstractBased on a corpus study conducted using the GerManC corpus (1650–1800), the paper sketches the functional and sociosymbolic development of subordinate clause constructions introduced by the subjunctor da ‘since’ in different text genres. In the second half of the 17th and the first half of the 18th century, the da clauses were characterized by semantic vagueness: Besides temporal, spatial and causal relations, the subjunctor established conditional, concessive, and adversative links between clauses. The corpus study reveals that different genres are crucial to the readings of da clauses. Spatial and temporal usages, for example, occur more often in sermons than in other genres. The conditional reading, in contrast, strongly tends to occur in legal texts, where it displays very high frequency. This could be the reason why da clauses carry indexical meaning in contemporary German and are associated with formal language. Over the course of the 18th century, the causal usages increase in all genres. Surprisingly, these causal da clauses tend to be placed in front of the matrix clause despite the overall tendency of causal clauses to follow the matrix clause.

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