Forms of Sounds as Shown on an Oscilloscope by Roulette Figures     

Barton GW  Barton SH 《Science (New York, N.Y.)》1963,142(3598):1455-1456

It has been found that with an oscilloscope driven through a simple network of two resistors and two capacitors it is possible to produce recognizable pictures from speech sounds. These pictures thus become a natural phonetic alphabet, with which both standard pronunciation and the nuances of dialect and accent can be represented. While a given speech sound has certain invariant characteristics, it has also an overlay of accent, which can be represented in the alphabetic character. It is suggested that the technique may be useful in teaching deaf children to speak.  相似文献   

Superradiance in a torus magnetosphere around a black hole     

van Putten MH 《Science (New York, N.Y.)》1999,284(5411):115-118

The coalescence of a neutron star and a black hole in a binary system is believed to form a torus around a Kerr black hole. A similarly shaped magnetosphere then results from the remnant magnetic field of the neutron star. In the strong-field case, it contains a cavity for plasma waves located between the barrier of the gravitational potential and the surrounding torus. This cavity may be unstable to superradiance of electromagnetic waves. Superradiant amplification of such waves, initially excited by turbulence in the torus, should inflate into a bubble in a time as short as approximately 0.75 (1 percent/&cjs3539;epsilon&cjs3539;2)(M/7M middle dot in circle) seconds approximately 0.15 to 1.5 seconds, assuming an efficiency &cjs3539;epsilon&cjs3539;2 = 0.5 to 5 percent and a mass M = 7M middle dot in circle. These bubbles may burst and repeat, of possible relevance to intermittency in cosmological gamma-ray bursts. The model predicts gamma-ray bursts to be anticorrelated with their gravitational wave emissions.  相似文献   

Comparative contents of dietary fiber, total phenolics, and minerals in persimmons and apples   总被引：3，自引：0，他引：3  

Gorinstein S  Zachwieja Z  Folta M  Barton H  Piotrowicz J  Zemser M  Weisz M  Trakhtenberg S  Màrtín-Belloso O 《Journal of agricultural and food chemistry》2001,49(2):952-957

Dietary fibers, major phenolics, main minerals, and trace elements in persimmons and apples were analyzed and compared in order to choose a preferable fruit for an antiatherosclerotic diet. Fluorometry and atomic absorption spectrometry following microwave digestion were optimized for the determination of major phenolics and minerals. Total, soluble, and insoluble dietary fibers, total phenols, epicatechin, gallic and p-coumaric acids, and concentrations of Na, K, Mg, Ca, Fe, and Mn in whole persimmons, their pulps, and peels were significantly higher than in whole apples, pulps, and peels (P < 0.01-0.0025). Conversely, the contents of Cu and Zn were higher in apples than in persimmons. In persimmons and apples all of the above components were higher in their peels than in whole fruits and pulps. The relatively high contents of dietary fibers, total and major phenolics, main minerals, and trace elements make persimmon preferable for an antiatherosclerotic diet.  相似文献   

The status and protection of notified sites of special scientific interest in South-East England     

P.M. Barton  G.P. Buckley 《Biological conservation》1983,27(3):213-242

Records of Sites of Special Scientific Interest (SSSIs) held within the South-East Region of the Nature Conservancy Council were examined. Reasons for site designation were complex and depended upon several flexible conservation criteria, as well as administrative considerations. The wide range of semi-natural habitats concerned were associated with poor, unproductive land, of little value to agriculture. However, SSSI status often failed to prevent damage by agencies such as farming, urban development and forestry, and resulted in a constant stream of proposals to develop or improve the land. Of these, the non-statutory consultations, especially those involving agricultural improvements, were most successfully implemented. Although urban development applications were more frequent, especially in densely populated counties, they were less successful because of existing planning controls.Pressures of all kinds resulted in the loss, or radical alteration of 6% of the notified SSSI area in Kent during an eleven year period (1968–1979), and affected two-thirds of all sites. A number of case studies are used to illustrate the main reasons for these losses, and the likelihood of future damage is discussed in the context of the greater protection measures now afforded by the Wildlife and Countryside Act of 1981.  相似文献   

Analysis of fiber content in flax stems by near-infrared spectroscopy     

Barton FE  Akin DE  Morrison WH  Ulrich A  Archibald DD 《Journal of agricultural and food chemistry》2002,50(26):7576-7580

The conventional means of measuring the fiber content of flax is time-consuming and laborious, and the results obtained vary with the analysis technique used. The plant tissues must first be "retted", a process by which the fibers are separated from the rest of the stem, either by indigenous organisms in the soil when the stems are left in the field or by water (anerobic bacteria) or enzymatic retting. The fiber content is then determined by mechanical or manual separation. In this study, fiber content of flax stems was measured rapidly and objectively by near-infrared spectroscopy (NIRS) using whole pieces of stem in a large cell, in reflectance mode. Compared to the conventional method, the standard error of performance of the NIRS method was between 0.96 and 1.45% (dry matter basis), depending on the model and data processing used. NIRS calibrations were generated by hand separation of fiber from water-retted specimens. The water retting procedure takes several days to complete and requires considerable trained labor to complete the hand separation step. The NIRS procedure was conducted on pieces of stem to simulate measurement in the field.  相似文献   

Determination of acid-detergent fiber and crude protein in forages by near-infrared reflectance spectroscopy: collaborative study   总被引：1，自引：0，他引：1  

F E Barton  W R Windham 《Journal of the Association of Official Analytical Chemists》1988,71(6):1162-1167

A collaborative study was conducted to determine the standard error of difference among laboratories for near-infrared reflectance spectroscopic (NIRS) determination of acid-detergent fiber (ADF) and crude protein in forages. The 6 participating laboratories were members of the USDA/ARS National Near-Infrared Reflectance Spectroscopy Forage Research Project. The NIRS calibration equations were developed in the Associate Referee's laboratory for crude protein and ADF and were transferred to the instrument in each of the other collaborating laboratories. The calibration set included over 650 diverse forage samples with crude protein and ADF calibration data; the validation set included 94 samples of bermudagrass. Among-laboratory reproducibility for the NIRS method, calculated as the relative standard deviation for reproducibility (RSDR), was 1.14% for ADF and 0.42% for crude protein. The variance component for among-laboratory variation (coefficient of variation) was 2.54% for ADF and 2.89% for crude protein. These results confirm that it is possible to calibrate, validate, and transfer (NIRS) equations and data among laboratories for the accurate determination of ADF and crude protein, and thereby demonstrate that NIRS can be used as a standard method for the analysis of forages. The method has been adopted official first action.  相似文献   

Use of mass spectrometry in the chemical analysis of organophosporus compounds]     

F Bartonícek  J Hrusovsky  L Hanus 《Veterinární medicína》1977,22(12):713-721

The authors studied the possibility of using mass spectrometry in the chemical analysis of the biologically highly active organophosphorus compounds. The results show that methylthiophosphorous acid O-ethyl-S-(2-dimethylaminoethyl) ester has the most complex mass spectrum of all the substances under study. In the spectrum characteristic fragments were detected, having m/e values of 42, 44, 58, 71 and 72 [corresponding to the presence of the (CH3)2NCH2CH2-group], and 81, 95, 97, 105 and 125 which are characteristic of the phosphoester group. Mass spectrometric analysis, performed in this study, proved that the MS method is suitable for a qualitative analysis of biologically highly active organophosphorus compounds such as methylthiophosphorous acid O-ethyl-S-(2-dimethylaminoethyl) ester.  相似文献   

Gaswechselmessungen an Fababohnen-Blättern (Vicia faba L.)     

K. Barton  G. Pommer  D. Knoppik 《Journal of Agronomy and Crop Science》1995,174(2):117-124

Measurement of gas exchange in faba-bean leaves ( Vida faba L.)
By means of gas-exchange measurements (minicuvette system and porometer), photosynthesis and its light dependence was investigated on attached leaves of different varieties of faba beans. The results showed no relevant difference in photosynthetic capacity for the varieties. This is true also for parameters calculated from light dependence, i.e. light compensation point, light saturation, and quantum yield. Generally, the light compensation point lay under 50 μE PAR/m²/s and light saturation was reached at about 1400 μE PAR/m²/ s. Photosynthesis was strongly dependent on leaf age and difference in photosynthetic capacity due to different varieties could be excluded as an essential reason for different rates of flowers dropping and pod dropping in faba beans.  相似文献   

Composition of cuts and carcasses of New Zealand lamb when graded by United States grade standards     

J D Kemp  R A Barton 《Journal of animal science》1969,28(3):324-330

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Infectious bovine keratoconjunctivitis: seasonal variation in cultural, biochemical and immunoreactive properties of Moraxella bovis isolated from the eyes of cattle   总被引：2，自引：0，他引：2  

A W Lepper  I J Barton 《Australian veterinary journal》1987,64(2):33-39

The eyes of 20 young cattle were examined over an 18 month period in which 12 members of the group contracted infectious bovine keratoconjunctivitis (IBK). On each of 23 occasions cultural, biochemical and immunoreactive properties of up to 6 isolates of Moraxella bovis derived from each eye were determined. Relationships between the clinical response of eyes, phenotypic properties of M. bovis and annual variations in the level of solar ultraviolet radiation of 280 to 320 nm wavelength were examined. M. bovis was isolated from all IBK-affected and some unaffected eyes less than one month after the maximum annual level of the mean weekly UV radiation (2,840 mWh.m-2 X nm-1) was recorded. A high proportion of M. bovis from IBK lesions were simultaneously active in haemolysis, agar corrosion, gelatin liquefaction and litmus milk peptonisation. Some of these characteristics showed marked dissociation despite consistent reactivity in the fluorescent antibody test, which had a sensitivity and specificity of 95%. Fall in the mean weekly level of UV radiation below 1,438 mWh X m-2 X nm-1 in autumn was accompanied by healing of ulcers, persistent scar formation and a decline in the number of M. bovis isolated from affected eyes. A slower decline in the number of M. bovis isolated from apparently healthy eyes occurred in the winter and occasional fresh IBK lesions occurred.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献