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21.
Belton MJ 《Science (New York, N.Y.)》1985,230(4731):1229-1236
Halley's comet is the focus of an international scientific enterprise now under way. Ground-based astronomical observations are already yielding new information about the comet's nucleus and atmosphere. In the coming year, remote and in situ investigations from the ground, Earth orbit, Venus orbit, interplanetary space, and within the comet itself are expected to reveal much more. The climax of the enterprise will be the penetration of an armored European spacecraft into the center of the comet in March 1986.  相似文献   
22.
Beer contains a very complex mixture of nutrients, which in this work are identified to some extent by high-field high-resolution nuclear magnetic resonance (NMR) one- and two-dimensional methods. The (1)H NMR spectrum of beer shows a predominance of strongly overlapped peaks arising from several carbohydrates. Minor components are clearly observed both in the aliphatic and in the aromatic regions of the spectrum. With the aid of two-dimensional methods, spectral assignment was carried out, enabling the identification of approximately 30 compounds and identifying about the same number of spin systems for further assignment. The variability of the spectral profile of beers differing in type and label was studied by principal component analysis (PCA), and it was found that, although some distinction is achieved on the basis of the aliphatic and sugar compositions, clearer separation between ales and lagers is obtained by PCA of the aromatic profiles alone. The potential of this technique as a rapid and informative quality control tool is discussed.  相似文献   
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Serotypes of 93 Australian isolates of Erysipelothrix rhusiopathiae from diseased domestic animals and poultry and a variety of captive wild birds and animals were determined by double diffusion gel precipitation. Two isolates, from the faeces of a swallow were also examined. Serotypes 1a, 1b and 2 were isolated from pigs and serotypes 1a, 1b, 2, 5, 15 and 21 from sheep or goats. Erysipelas in poultry was attributed to serotypes 1b, 5, 15 and 16. In captive wild birds serotypes 1b, 5, 6, 8, 14, 21 and an isolate reactive with antiserum to strain Seehecht were associated with septicaemic deaths. Single isolates from tissues of a bilby (Macrotis lagotis), black rat (Rattus rattus), brown snake (Pseudechis australis) and a bandicoot (Isoodon macrouris) were classified as serotypes 4, 4, 7, and 10 respectively. Six isolates were not able to be typed. Serotype 1b was the most widely distributed and most common (28%), being associated with disease in pigs, sheep, poultry and wild birds. Serotypes 1a or 2 were found in a more restricted range of animals, being commonly associated with erysipelas in pigs, less commonly in sheep and infrequently in other species. From diseased pigs, 26 of 33 isolates (79%) were serotypes 1a and 1b.  相似文献   
25.
SUMMARY To test the hypothesis that joint incongruity contributes to the pathogenesis of elbow osteochondrosis, the left and right radius and ulna of 20 young large breed dogs were measured to determine any variation in length and to observe any incongruity of the elbow joint. Both lame and normal dogs were included in the study. Nine of the 20 dogs had marked disparity in radial and ulnar lengths yet only one had obvious elbow joint incongruity. The use of a sliding osteotomy for the treatment of fragmented coronoid process and a lengthening osteotomy for the treatment of an ununited anconeal process is also discussed. All four dogs treated with a sliding osteotomy showed a marked clinical improvement, and two of the three dogs treated with a lengthening osteotomy showed radiographic fusion of the anconeal process.  相似文献   
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We report the direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission. Three anomalously colored areas are shown to include water ice on the basis of their near-infrared spectra, which include diagnostic water ice absorptions at wavelengths of 1.5 and 2.0 micrometers. These absorptions are well modeled as a mixture of nearby non-ice regions and 3 to 6% water ice particles 10 to 50 micrometers in diameter. These particle sizes are larger than those ejected during the impact experiment, which suggests that the surface deposits are loose aggregates. The total area of exposed water ice is substantially less than that required to support the observed ambient outgassing from the comet, which likely has additional source regions below the surface.  相似文献   
29.
Nonsteroidal anti‐inflammatory drugs (NSAIDs) are widely used to provide analgesia in clinical veterinary medicine, but there are few objective data evaluating this effect under controlled conditions in cats. Analgesia is more difficult to detect with acute analgesiometry after NSAIDs than after opioids. This investigation aimed to adapt the feline thermal analgesiometry method previously employed with opioids ( Dixon et al. 2002 ) for use with NSAIDs. Ketoprofen, a COX1 inhibitor licensed for cats was chosen. Six cats (2 neutered, four entire females, weighing 2.2–5.4 kg) were studied in two blinded randomized crossover trials each at least 2 weeks apart. Thermal thresholds (TT) were measured using the thermal threshold‐testing device previously developed for cats. A heater element and temperature sensor in a small probe were held at constant pressure against the cats' shaved thorax with an elasticized band. Skin temperature was recorded before each test, then the heater activated. When the cat responded by flinching, turning or jumping the heater was turned off and the temperature recorded. In the first study TT were measured following subcutaneous (SC) injection of ketoprofen (2 mg kg?1) or a similar volume of saline. In the second study, prior to TT, and under isoflurane restraint, a mild inflammatory focus was produced at the probe site by five SC injections of 5 mg kaolin in 0.1 mL saline at each corner and in the center of a 1.5‐cm square. Saline or ketoprofen as in the first study were injected at the same time. Three baseline temperatures were recorded before any injections were given. Thermal thresholds were measured at 1 and 2 hours and then two‐hourly for 24 hours. Data were analysed using anova . Baseline skin temperature increased (37.3 ± 0.5–38.1 ± 0.8 °C) 24 hours after saline injection in study 2 (p < 0.05) but did not change after any other treatment. Thermal thresholds decreased (40.0 ± 1.3 to 39.1 ± 0.4 °C) 16 hours after ketoprofen in study 1 (p < 0.05) and increased (41.6 ± 1.5–44.8 ± 6.1 °C) 16–24 hours after ketoprofen in study 2 (p < 0.05), with no significant changes after saline. No obvious increase in sensitivity to thermal stimulation after kaolin injection was detected although obvious inflammation was present for up to 36 hours and the cats responded to digital pressure at the treated site. The method detected some effects of a COX1 selective NSAID and may be suitable for future NSAID studies in cats. However, a pressure stimulus ( Dixon et al. 2000) may prove better than thermal, and it requires investigation.  相似文献   
30.
AIMS: To compare two methods of applying rubber rings to the pedicles of yearling stags to induce analgesia in the antler prior to removal. To compare the application of a rubber ring with that of a lignocaine ring block of the antler pedicle on the efficacy and time course of the analgesia produced in yearling stags.

METHODS: Rubber rings were applied to the pedicles of 36 yearling stags that required velvet antler removal. The standard method, a doubled-over ring expanded and lowered down from the distal end of the antler and released midway down the pedicle, was compared with a cable-tie method on the other pedicle, where a ring was pulled around the pedicle by an electrical cable tie threaded through the ring. Brief electrical stimulation (train-of-four mode) was applied proximal and distal to the ring before, and at regular intervals for 1 hour after, application of the ring to a level that produced an auriculopalpebral reflex response.

In a second experiment, each pair of antlers per yearling stag (n=36) was allocated to one of three pairs of treatments, viz no treatment (control) and the cable-tie method as described above, control and local anaesthesia (a ring block of 2 ml 2% lignocaine per cm pedicle circumference), or the cable-tie method and local anaesthesia. Electrical stimulation (tetanic mode) was applied to each antler approximately 25 mm distal to the pedicle/antler junction before, and at intervals up to 1 hour after, application of treatments at a level required to produce a head/neck avoidance behavioural response.

In a third experiment, the two electrical stimulation protocols used above were directly compared by measuring the response of stags (n=8) to one protocol on each pedicle/antler prior to, and at intervals for 1 hour after, application of a rubber ring. At the end of each treatment in all three experiments, analgesia of the antler was established as a nil behavioural response of the stag to a saw cut to the antler (the ‘nick test’).

RESULTS: For both methods of application of a ring the minimum electrical stimulation required distal to the ring to elicit a reflex response increased from around 16 to 55 mA by 60 minutes. In contrast, the electrical stimulation required proximal to the ring remained low (~17.0 mA) throughout. No stag subjected to either of the methods of application responded to the nick test 60 minutes after application of the ring.

The electrical stimulation required to produce a behavioural response increased very rapidly in stags treated with local anaesthetic and at a slower rate in those treated with the cabletie method but showed no significant increase in control stags. After 4 and 30 minutes, for local anaesthesia and the cable-tie method, respectively, 95% of stags were not responding to 80 mA. A significantly greater proportion of stags with antlers treated with local anaesthetic and the cable-tie method did not respond to the nick test than controls, and there was no significant difference in the frequency of the response between stags with treated antlers.

The minimum current required to produce a response proximal to a rubber ring was slightly higher on average for train-of-four electrical stimulus (mean 18.1 (SD 2.6) mA) than for the tetanic mode (mean 11.9 (SD 2.5) mA). The increase in minimum current required to produce the respective response to stimulation distal to the ring was similar for both methods, although the maximum predicted value (67.4 mA) was lower for train-of-four than for the tetanic mode (84.5 mA). No stag responded to the nick test =60 minutes after application of the ring.

CONCLUSIONS: The cable-tie method was no different from the standard method as a procedure for producing analgesia in the antlers of yearling stags and should be accepted as an appropriate procedure for applying analgesic rings to yearling stags. The analgesia produced in the antlers of yearling stags by rubber rings applied by the cable-tie method to the pedicle was similar to that of a lignocaine ring block, but the time course for the development of analgesia was markedly different. Given that a lignocaine ring block is accepted as an adequate method of pain relief for antler removal, the application of rubber rings followed by a period of =30 minutes after application can be advocated as a viable alternative for pain relief.  相似文献   
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