排序方式： 共有46条查询结果，搜索用时 31 毫秒
1.
2.
3.
D. A. HOLLAND 《European Journal of Soil Science》1969,20(1):132-140
The application of regression theory to the construction of calibration curves for the estimation of water content from an observed radiation count is possible only when the relationship between count and water content is linear, a homogeneous error applies to the dependent variate, count, whatever its value, and the independent variate, water content, is determined free of error. Determination of the errors of estimation is further complicated by the necessity to fit the regression of count, as the dependent variate, on water content and then to invert the equation in order to estimate moisture content from count. It is shown that these requirements can be fulfilled by an initial transformation of the data and by repeated sub-sampling for the determination of water content. A method is given for calculating errors of estimation. Experimentally, it was found that a transformation (logarithmic) was necessary when calibrating a beta-gauge for leaf moisture measurement. When calibrating a neutron probe for soil-moisture measurement no transformation was required, but it was necessary to take repeated sub-samples for water content determinations. 相似文献
4.
Equine Post-anesthetic Lameness A Retrospective Study 总被引：1，自引：0，他引：1
MEGHAN T. RICHEY DVM MELISSA S. HOLLAND DVM DiplomateACVA CHARLES J. McGRATH DVM DiplomateACVA NICHOLAS H. DODMAN BVMS MRCVS DVA DipomateACVA DURWOOD B. MARSHALL ESS MICHAEL H. COURT BVSc DiplomateACVA WENDY M. NORMAN BVSc DAVID C. SEELER DVM MSC DiplomateACVA 《Veterinary surgery : VS》1990,19(5):392-397
The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors. 相似文献
5.
6.
PT Sprunger L Petersen EW Plummer E Laegsgaard F Besenbacher 《Science (New York, N.Y.)》1997,275(5307):1764-1767
Large-amplitude electron density oscillations were observed on a Be(0001) surface by means of variable-temperature scanning tunneling microscopy. Fourier transforms of the images showed a ring of radius 2kF, where kF is the Fermi wave vector of the Be(0001) surface state. This wavelength was expected from Friedel oscillations caused by electronic screening of surface defects, but the amplitude of the waves for energies near the Fermi energy was anomalously large and inconsistent with the Friedel concept of screening. The enhanced amplitude of the waves must be a many-body effect, either in the electron gas (possibly an incipient charge density wave) or in the response of the lattice (electron-phonon coupling). 相似文献
7.
Disease of geese caused by a new herpesvirus 总被引：3，自引：0，他引：3
PJ KETTERER BJ RODWELL HA WESTBURY† PT HOOPER† AR MACKENZIE‡ JG DINGLE§ HC PRIOR 《Australian veterinary journal》1990,67(12):446-448
A goose flock farmed outdoors in south-eastern Queensland suffered an outbreak of peracute disease with high death rate (97%). Small button ulcers and large plaques overlying lymphocyte aggregates were present on the mucosa of the small intestine of affected birds. Small white foci of necrosis and focal haemorrhages were seen in the livers. Numerous intranuclear inclusion bodies were observed microscopically in hepatocytes and a herpesvirus which grew rapidly in chicken kidney cells was isolated from tissues. Duck virus enteritis (DVE) was suspected but DVE antiserums failed to neutralise the virus. Further serological studies with a limited range of known avian herpesviruses have failed to identify the virus. Experimental transmission resulted in high mortality in geese (100%), lower mortality in ducklings and nil mortality in chickens. Surveillance studies showed no evidence of infection in domestic and wild birds beyond the original farm and the infection appears not to have been established in the area. Wild ducks, which were frequent visitors to the farm dam, were considered the most likely source of the infection. 相似文献
8.
C. A. BLAZE BVSC DipiomateACVA R. E. HOLLAND DVM MS A. L. GRANT BS 《Veterinary surgery : VS》1988,17(3):155-159
Ten neonatal calves were anesthetized with xylazine and ketamine intramuscularly and breathed air spontaneously. Drug injection was repeated after 45 minutes. Each injection resulted in a rapid and sustained increase in respiratory rate, but arterial carbon dioxide tension (PaCO2) increased, indicating hypoventilation. Arterial hypoxemia, primarily caused by hypoventilation, developed within 15 minutes of each injection, but gradually disappeared. Acidemia was primarily respiratory in origin. Heart rate and arterial blood pressure decreased for the duration of anesthesia (90 minutes). This form of anesthesia is a satisfactory alternative to inhalation anesthesia of neonatal calves. 相似文献
9.
10.
A system of detailed vegetation mapping has been developed for use on undulating terrain where there is a complex mosaic of soil types, drainage characteristics and plant communities and where topography is such that it is impossible to locate a position by reference solely to a map grid reference point, for example hill/moorland grazings, sand dunes and mud flats. The system involved using electronic surveying equipment to locate accurately, in terms of National Grid coordinates and altitude, a large number of points over the area to be surveyed for which vegetation types were identified and recorded. The merged location and vegetation data set for individual points were imported into a geographic information system (GIS) to map 'point' vegetation data accurately. The GIS was then used to create regions around points (voronoi) using Delaunay triangulation to produce a vegetation map. Altitude information was used within the GIS to produce a contour map of the surveyed area.
Vegetation was classified into communities of the British National Vegetation Classification and, although it does not describe all the variants within communities/sub-communities fully, extra information for individual point locations was stored in tables within the GIS. This information was readily accessed by using the mouse cursor to highlight a point and reveal a window containing all the tabulated information for that point.
This methodology was used to produce a reliable map that accurately positioned and mapped previously unmarked landscape features, new boundaries/fences, vegetation types and contours. This facility could be used for a variety of experimental, planning and consultancy applications including botanical survey work, grazing behaviour studies, conservation, land use planning and management. 相似文献
Vegetation was classified into communities of the British National Vegetation Classification and, although it does not describe all the variants within communities/sub-communities fully, extra information for individual point locations was stored in tables within the GIS. This information was readily accessed by using the mouse cursor to highlight a point and reveal a window containing all the tabulated information for that point.
This methodology was used to produce a reliable map that accurately positioned and mapped previously unmarked landscape features, new boundaries/fences, vegetation types and contours. This facility could be used for a variety of experimental, planning and consultancy applications including botanical survey work, grazing behaviour studies, conservation, land use planning and management. 相似文献