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991.
The metabolism of 14C-labeled 3-phenoxybenzoic acid, PBA, has been studied in cotton, vine, broad bean, soya bean, pea, lettuce, and tomato, using abscised leaves. PBA was converted into a range of polar products by esterification with glucose (in cotton and other species) and with glucosylarabinose and glucosylxylose (especially in vine leaves). Uptake of the glucose ester itself by cotton leaves also led to conversion into a more polar conjugate, probably the glucosylarabinose ester, which was not detectable following uptake of PBA. When PBA was applied to the surface of intact cotton leaves, it was slowly converted into products similar to those above. 相似文献
992.
993.
Noble GK Houghton E Roberts CJ Faustino-Kemp J de Kock SS Swanepoel BC Sillence MN 《Journal of animal science》2007,85(1):163-171
Insulin-like growth factor-1 could be a useful marker in the horse for diagnostic, selection, or forensic purposes, provided its physiological regulation is well understood. The objective of this study was to investigate factors, such as acute exercise, fitness training, time of day, sex, and age, that may influence serum IGF-1 in normal, healthy horses. Throughout a 9-wk training program, 6 geldings maintained a mean (+/- SEM) IGF-1 concentration of 302 +/- 29 ng/mL. Moderate or high intensity exercise had no effect on IGF-1 concentrations, when pre- and postexercise values were compared. Over a 24-h period, there was some variation in IGF-1 concentrations but no clear diurnal rhythm. Concentrations of IGF-1 were measured in a large population of thoroughbred horses (1,880) on 3 continents. The population deviated slightly from a normal distribution (P < 0.001) because of large IGF-1 concentrations in 10 horses. The global mean IGF-1 concentration was 310 +/- 2.2 ng/mL, with a greater mean value (P < 0.001) in gonad-intact males (336 +/- 5.6 ng/mL) than in females (303 +/- 3.2 ng/mL) or geldings (302 +/- 3.2 ng/mL). However, the greatest IGF-1 concentrations observed for all stallions, mares, and geldings were 627, 676, and 709 ng/mL, respectively. In mares and geldings, IGF-1 concentrations showed a gradual decrease with advancing age (P < 0.001), but the effect was much less marked in stallions. This study confirms that IGF-1 concentrations are stable, compared with GH concentrations, in the horse and that a meaningful measure of IGF-1 status can be obtained from a daily serum sample. 相似文献
994.
Comparison of abdominal ultrasound and magnetic resonance imaging for detection of abdominal lymphadenopathy in dogs with metastatic apocrine gland adenocarcinoma of the anal sac 下载免费PDF全文
C. L. Anderson C. S. MacKay G. D. Roberts J. Fidel 《Veterinary and comparative oncology》2015,13(2):98-105
Imaging studies in humans with anal and rectal cancer indicate that magnetic resonance imaging (MRI) is a more sensitive technique than abdominal ultrasound (AUS) for the detection of abdominal lymphadenopathy. The purpose of this retrospective study was to directly compare the efficacy of these two techniques in detecting abdominal lymphadenopathy in dogs with apocrine gland adenocarcinoma of the anal sac (AGAAS). Six dogs with histologically confirmed AGAAS and histopathologic confirmation of metastasis to abdominal lymph nodes (LNs) had AUS and abdominal MRI. AUS identified lymphadenopathy in two of six dogs, whereas MRI identified lymphadenopathy in all the six dogs. Lymphadenopathy was predominantly sacral in location, with involvement of the medial iliac and hypogastric LNs in only two cases. These data suggest that MRI is more sensitive than AUS for detecting sacral abdominal lymphadenopathy in dogs with AGAAS. As such, MRI could be considered in any patient with AGAAS for initial staging of this disease. 相似文献
995.
996.
Michele C. Marra Roderick M. Rejesus Roland K. Roberts Burton C. English James A. Larson Sherry L. Larkin Steve Martin 《Precision Agriculture》2010,11(3):215-238
Survey data from cotton farmers in six southeastern states of the USA were used to estimate the demand and willingness-to-pay
(WTP) for either retrofitting yield monitors onto cotton pickers or to purchase a yield monitor as an option with a new cotton
picker. ‘Don’t know’ responses were either omitted, combined with ‘no’ responses or included as a separate category for comparing
WTP and estimates of the price elasticity of demand. Our results suggest that treating the ‘don’t know’ response as a separate
category provides WTP estimates that are more consistent with expectations than the other approaches. The estimated price
elasticities and demand curves indicate that previous users of precision technology are more responsive to changes in price
of cotton yield monitors and would be more likely to adopt them when the price decreases. These demand and WTP estimates provide
important information that can be used by those who sell cotton yield monitors, as well as policy-makers who may wish to subsidize
this technology. Referendum contingent valuation was useful for evaluating the demand for any new technology. 相似文献
997.
Jonathan C. Walton Roland K. Roberts Dayton M. Lambert James A. Larson Burton C. English Sherry L. Larkin Steven W. Martin Michele C. Marra Kenneth W. Paxton Jeanne M. Reeves 《Precision Agriculture》2010,11(2):135-147
Technology adoption in precision agriculture has received considerable attention, while abandonment has received little. Survey
data are now available to evaluate adoption and abandonment decisions. Understanding the factors motivating technology adoption
and abandonment has implications for educational efforts directed toward improving the efficiency of production inputs and
for research and development to improve the value of precision agriculture technologies. The objective of this research was
to identify factors motivating the adoption and abandonment of grid soil sampling in precision cotton production. These decisions
were evaluated assuming a random utility model. Data were obtained from a 2005 survey of cotton producers in 11 Southeastern
states in the USA. Results from limited dependent variable regressions indicate that younger producers who farmed more cotton
area, owned more of their cropland, planted larger amounts of non-cotton area, used a computer for farm management and used
a Personal Digital Assistant (PDA) in the field were more likely to adopt grid soil sampling for cotton precision farming.
Results also suggest that producers with more cotton area who owned livestock and adopted management zone soil sampling were
more likely to abandon grid soil sampling, while those who used a PDA in the field, used grid soil sampling for more years
and followed up grid soil sampling with variable-rate fertilizer application were less likely to abandon grid soil sampling
for cotton production. 相似文献
998.
999.
<正>日粮纤维是家畜饲料的重要组成部分。益生木质纤维素(eubiotic lignocellulose)由新鲜木材制成,是一种相对较新的饲料原料,试验证明它是一种非常有价值的饲用纤维原料,对动物营养有众多的益处。日粮纤维是单胃动物消化调节的必需物质。高淀粉日粮易于快速发酵,通常在消化过程的早期就几乎被完全发酵,到达大肠时极少或已无物可发酵。在日粮中添加纤维能够使发酵进程后移至结肠,并且促进有益菌的增殖。益生菌所产生的挥发性脂肪酸能够提高肠道的健 相似文献
1000.
Darby JA 《Pest management science》2008,64(5):519-526
BACKGROUND: Most fumigants are adsorbed by grain at differing rates depending on the fumigant or grain type. Sorption can reduce the concentrations of fumigation doses to sublethal levels before grain has been disinfested. A model to predict fumigant losses due to sorption in industrial scenarios is needed. RESULTS: This work reviews the kinetics of grain fumigant sorption and develops a new alternative model based upon key factors established from the literature and batch experimental results. The novel model accounts for linear mass transfer within the grain, irreversible 'binding' and linear partitioning of the fumigant to the grain. Model coefficients were estimated by minimizing the sum of squared residuals between model predictions and experimental data. The model was compared with other options including diffusion into spheres, and results for methyl bromide and phosphine are provided. CONCLUSION: The model describes the transient changes of fumigant concentrations in both the intergranular air and grain. It provides the capacity to predict fumigant concentrations throughout grain stacks for a wide range of scenarios of industrial importance. 相似文献