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41.
Valrie Chetboul D. Tessier D. Rosenberg M. Boussouf L. Escoffier B. Lugardon J-L. Pouchelon 《Journal of Veterinary Cardiology》1999,1(1):143
Definitive diagnosis of mitral and aortic valvular endocarditis in a dog was based on echocardiograpic findings and was then confirmed by positive blood culture. Abdominal ultrasound examination revealed a renal abcess. This case illustrates that echocardiography associated with abdominal ultrasound has become an essential tool for the diagnosis of bacterial endocarditis and for the detection of sequela or initial source of bacteriemia, while waiting for blood culture results. A short review of echocardiographic and Doppler abnormalities associated with bacterial endocarditis is presented. 相似文献
42.
BHG Pearse RJ Traub A Davis R Cobbold PB Vanderlinde 《Australian veterinary journal》2010,88(7):260-262
Objective The first national abattoir survey of Cysticercus bovis (‘beef measles’) in cattle was conducted in February 2008. Methods During the data collection period, 493,316 cattle were subjected to standard postmortem procedures, including incision of the masseter and heart muscles. On-site veterinarians were asked to record the location of any C. bovis cysts, as well as the National Livestock Identification System ear tag numbers of infected animals. Veterinarians were asked to submit samples for laboratory confirmation by histology and polymerase chain reaction testing. Results Of the 23 samples submitted, none was positive for C. bovis by either diagnostic method. Conclusions Occasional, isolated diagnoses of beef measles are still made in most states of Australia, but since the last regional surveys were conducted 30 years ago, when the estimated prevalence was 50 to 200 per 100,000 cattle slaughtered, the parasite has become extremely rare. 相似文献
43.
Summary The EVIKA Research Centre has developed a disease eradication system for the initial material of seed potato, which consists
of 1. Selection of the initial material for eradication, plant thermotherapy, meristem tip cultivation and testing for viruses;
2. Re-eradication (thermotherapy of test-tube plants, cultivation of meristem tips, testing for viruses, testing of varietal
quality and yield of disease-free meristem clones, and the selection of meristem clones with best varietal characteristics;
3. Renewing of the initial material (all processes as above, but the initial material is selected from the seed potatoes grown
for at least 3 years in the field).
Field trials were conducted after the second cycle of eradiaction to determine whether the plantlets were true-to-type and
to assess the yield, disease resistance and tuber dry matter. Recently we have also started in vitro testing of meristem plants
resistance to late blight, hoping that this approach will improve the selection efficiency.
Propagation and growing of the seed tubers consists of 3 main steps: 1. Plantlet propagation in vitro; 2. Greenhouse propagation
in plastic rolls; and 3. Planting the first generation tubers in the field. Under our conditions it is the cheapest, simplest
and most effective way.
Multiplication of the meristem-derived plants is done by shoot tip cuttings in a greenhouse in plastic rolls with peat as
the growing medium. The first generation of seed tubers is grown in the field. In our trials plant productivity was affected
by the method of multiplication, growing conditions and genotype. The highest yield per hectare was obtained with plants multiplied
in plastic rolls. The in vitro plants had more tubers per plant than plants multiplied in plastic rolls. In seed production
fields the productivity of plants was more influenced by following our instructions than by multiplication and growing methods.
The number of tubers per plant obtained with over 0.5 million plants was 6.5–9.0.
In the second generation of seed tubers, grown under equal density, the greater-sized tubers gave more tubers with lower weight
than the smaller-sized tubers. Cutting tubers had no effect on the plant development and tuberization. 相似文献
44.
Continental extension and volcanism are generally thought to be complementary. Stratigraphic and structural data from some highly extended parts of the Basin and Range province reveal instead that rapid extension appears to have suppressed volcanism. This relation may reflect enhanced crystallization of midcrustal magmas during extension resulting from exsolution of magmatic volatiles, increased interaction of magmas with meteoric water, and dispersal of magma into smaller bodies. Some rift environments may thus be characterized by voluminous synextensional plutonism with little or no concomitant volcanism. 相似文献
45.
46.
Miguel L. Villarreal Robert H. Webb Laura M. Norman Jennifer L. Psillas Abigail S. Rosenberg Shinji Carmichael Roy E. Petrakis Philip E. Sparks 《Land Degradation \u0026amp; Development》2016,27(4):1106-1121
Decades of intensive off‐road vehicle use for border security, immigration, smuggling, recreation, and military training along the USA–Mexico border have prompted concerns about long‐term human impacts on sensitive desert ecosystems. To help managers identify areas susceptible to soil erosion from anthropogenic activities, we developed a series of erosion potential models based on factors from the Universal Soil Loss Equation (USLE). To better express the vulnerability of soils to human disturbances, we refined two factors whose categorical and spatial representations limit the application of the USLE for non‐agricultural landscapes: the C‐factor (vegetation cover) and the P‐factor (support practice/management). A soil compaction index (P‐factor) was calculated as the difference in saturated hydrologic conductivity (Ks) between disturbed and undisturbed soils, which was then scaled up to maps of vehicle disturbances digitized from aerial photography. The C‐factor was improved using a satellite‐based vegetation index, which was better correlated with estimated ground cover (r2 = 0·77) than data derived from land cover (r2 = 0·06). We identified 9,780 km of unauthorized off‐road tracks in the 2,800‐km2 study area. Maps of these disturbances, when integrated with soil compaction data using the USLE, provided landscape‐scale information on areas vulnerable to erosion from both natural processes and human activities and are detailed enough for adaptive management and restoration planning. The models revealed erosion potential hotspots adjacent to the border and within areas managed as critical habitat for the threatened flat‐tailed horned lizard and endangered Sonoran pronghorn. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
47.
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49.
RNA required for import of precursor proteins into mitochondria 总被引:4,自引:0,他引:4
F A Firgaira J P Hendrick F Kalousek J P Kraus L E Rosenberg 《Science (New York, N.Y.)》1984,226(4680):1319-1322
A cytoplasmic RNA moiety is necessary for posttranslational uptake of nuclear-encoded mammalian proteins destined for the mitochondrial matrix. Post-translational addition of ribonuclease to a reticulocyte lysate-programmed cell-free translation mixture inhibited subsequent import of six different mitochondrial matrix enzyme precursors into rat liver mitochondria. The required RNA is highly protected, as indicated by the high concentrations of ribonuclease necessary to produce this inhibition. The dependence of the inhibitory effect on temperature, duration of exposure to ribonuclease, and availability of divalent cations is characteristic of the nuclease susceptibility of ribonucleoproteins. The ribonuclease-sensitive component was found in a 400-kilodalton fraction which contains the mitochondrial protein precursors. 相似文献
50.
Sarah M Glaser Michael J Fogarty Hui Liu Irit Altman Chih‐Hao Hsieh Les Kaufman Alec D MacCall Andrew A Rosenberg Hao Ye George Sugihara 《Fish and Fisheries》2014,15(4):616-633
Complex nonlinear dynamics in marine fisheries create challenges for prediction and management, yet the extent to which they occur in fisheries is not well known. Using nonlinear forecasting models, we analysed over 200 time series of survey abundance and landings from two distinct ecosystems for patterns of dynamic complexity (dimensionality and nonlinear dynamics) and predictability. Differences in system dimensionality and nonlinear dynamics were associated with time series that reflected human intervention via fishing effort, implying the coupling between human and natural systems generated dynamics distinct from those detected in the natural resource subsystem alone. Estimated dimensionality was highest for landings and higher in abundance indices of unfished species than fished species. Fished species were more likely to display nonlinear dynamics than unfished species, and landings were significantly less predictable than abundance indices. Results were robust to variation in life history characteristics. Dynamics were predictable over a 1‐year time horizon in seventy percent of time series, but predictability declined exponentially over a 5‐year horizon. The ability to make predictions in fisheries systems is therefore extremely limited. To our knowledge, this is the first cross‐system comparative study, and the first at the scale of individual species, to analyse empirically the dynamic complexity observed in fisheries data and to quantify predictability broadly. We outline one application of short‐term forecasts to a precautionary approach to fisheries management that could improve how uncertainty and forecast error are incorporated into assessment through catch limit buffers. 相似文献