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991.
A fault-detection matrix contains sufficient information for finding minimal-length, fault-diagnosis test sets. The necessary and sufficient condition is that the submatrix of the fault-detection matrix must not contain equal rows. Cited examples demonstrate that characteristics in the fault-detection matrix can be used to facilitate the search for tests. 相似文献
992.
Scott E. Blouin Edwin J. Chamberlain Paul V. Sellmann Donald E. Garfield 《Cold Regions Science and Technology》1979,1(1):3-16
Sediments beneath the Beaufort Sea near Prudhoe Bay, Alaska, were probed at 27 sites using a static cone penetrometer to determine engineering properties and distribution of material types, including ice-bonded sediments. The probe, designed and constructed at the Cold Regions Research and Engineering Laboratory, provided both point and casing resistance data and thermal profiles. At five sites these data were correlated with information from adjacent drilled and sampled holes. These control data and the quality of the probe information permitted profiles of sediment type and occurrence of ice-bonded material to be developed along three lines that included various geological features and depositional environments.Material properties were quite variable in the upper 14 m of sediments probed. In general, softer, finer-grained sediments occurred in the upper layers, while penetration refusal was met in stiff gravels 10 to 12 m below the seabed.Seabed temperatures during the study were all below 0°C. However, because of uncertainties in freezing point values caused by brines, evaluation of the penetration resistance data was required to identify the occurrence of ice-bonded sediments. The coupling of thermal and penetration resistance data revealed that seasonally ice-bonded sediments occurred where the sea ice froze back to or near the seabed. Deeper, perennially frozen sediments also appeared to be present at several probe sites. 相似文献
993.
Acyl-CoA: alcohol transacylase activity was demonstrated in cell-free homogenates of developing jojoba seeds. The optimal
pH was 8.0–8.1. Under optimal conditions, wax formation had a nearly linear relationship with extract concentration; the time
course of wax formation was also linear up to 30 min.cis-11-Eicosenol was the most effective alcohol substrate whereas tetradecanol, octadecanol, dodecanol,cis-9-octadecanol, andcis-13-eicosenol gave progressively lower activities. Either saturated or unsaturated acyl-CoA with 18 or 20 C-atoms had similar
activity. The enzyme was fairly stable at 0 C, less stable at RT and labile above 30 C. Differential centrifugation showed
that the 12,000 × g fat pad was the most active in wax formation; to maximize the activity, a 12,000 × g supernatant appeared
to be necessary. This factor in the supermatant was thermolabile and nondialyzable. 相似文献
994.
A small, low-cost, highly sensitive system to record geomagnetic fluctuations on the ocean floor is described. The technique employed is to amplify the effective sensitivity of the Cs-vapor magnetometer with an intermediate stage discriminator amplifier voltagecontrolled oscillator prior to magnetic recording. The resultant overall electronic system noise level obtained is well below the inherent noise level of the sensor, permitting accurate measurement of undersea magnetic fluctuations up to 5 Hz. 相似文献
995.
996.
The current impetus for peer review had its origin in issues of cost containment, bolstered by intentions to improve quality of service. Peer review is usually conceived of as a way to either police a profession by ridding it of the few "bad actors" or to assure that services delivered meet minimum standards. The present article argues, however, that a more useful philosophy of peer review is to assume that it is at the heart of the definition of a profession. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
998.
Characterization of a prostaglandin-like metabolite of linolenic acid produced by a flaxseed extract
One of the products formed upon incubation of linolenic acid (cis9,12,15-octadecatrienoic acid) with an extract of flaxseed acetone powder has been characterized as 8-[2-(cis-pent-2′-enyl)-3-oxo-cis-cyclopent-4-enyl]octanoic acid. The cyclopentenone ring structure of this acid is analogous to that of the A-type prostaglandins
produced in mammalian systems. 相似文献
999.
Styrene-acrylonitrile copolymers, SAN, are known to be miscible with poly(methyl methacrylate). Based on the presence of a single composition dependent glass transition and lower critical solution temperature behaviour, it is shown that SAN is also miscible with poly(ethyl methacrylate). However, the SAN does not appear to be miscible with other polymethacrylates or polyacrylates. 相似文献
1000.