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841.
The objective of this study was to compare performance of partial least square regression (PLSR) and best narrowband normalize nitrogen vegetation index (NNVI) linear regression models for predicting N concentration and best narrowband normalize different vegetation index (NDVI) for end of season biomass yield in bioenergy crop production systems. Canopy hyperspectral data was collected using an ASD FieldSpec FR spectroradiometer (350–2500 nm) at monthly intervals in 2012 and 2013. The cropping systems evaluated in the study were perennial grass {mixed grass [50 % switchgrass (Panicum virgatum L.), 25 % Indian grass “Cheyenne” (Sorghastrum nutans (L.) Nash) and 25 % big bluestem “Kaw” (Andropogon gerardii Vitman)] and switchgrass “Alamo”} and high biomass sorghum “Blade 5200” (Sorghum bicolor (L.) Moench) grown under variable N applications rates to estimate biomass yield and quality. The NNVI was computed with the wavebands pair of 400 and 510 nm for the high biomass sorghum and 1500 and 2260 nm for the perennial grass that were strongly correlated to N concentration for both years. Wavebands used in computing best narrowband NDVI were highly variable, but the wavebands from the red edge region (710–740 nm) provided the best correlation. Narrowband NDVI was weakly correlated with final biomass yield of perennial grass (r2 = 0.30 and RMSE = 1.6 Mg ha?1 in 2012 and r2 = 0.37 and RMSE = 4.0 Mg ha?1, but was strongly correlated for the high biomass sorghum in 2013 (r2 = 0.72 and RMSE = 4.6 Mg ha?1). Compared to the best narrowband VI, the RMSE of the PLSR model was 19–41 % lower for estimating N concentration and 4.2–100 % lower for final biomass. These results indicates that PLSR might be best for predicting the final biomass yield using spectral sample obtained in June to July, but narrowband NNVI was more robust and useful in predicting N concentration. 相似文献
842.
Comparison of direct sampling and brochoalveolar lavage for determining active drug concentrations in the pulmonary epithelial lining fluid of calves injected with enrofloxacin or tilmicosin
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![点击此处可从《Journal of veterinary pharmacology and therapeutics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D. M. Foster H. J. Sylvester M. G. Papich 《Journal of veterinary pharmacology and therapeutics》2017,40(6):e45-e53
Antibiotic distribution to interstitial fluid (ISF) and pulmonary epithelial fluid (PELF) was measured and compared to plasma drug concentrations in eight healthy calves. Enrofloxacin (Baytril® 100) was administered at a dose of 12.5 mg/kg subcutaneously (SC), and tilmicosin (Micotil® 300) was administered at a dose of 20 mg/kg SC. PELF, sampled by two different methods—bronchoalveolar lavage (BAL) and direct sampling (DS)—plasma, and ISF were collected from each calf and measured for tilmicosin, enrofloxacin and its metabolite ciprofloxacin by HPLC. Pharmacokinetic analysis was performed on the concentrations in each fluid, for each drug. The enrofloxacin/ciprofloxacin concentration as measured by AUC in DS samples was 137 ± 72% higher than in plasma, but in BAL samples, this value was 535 ± 403% (p < .05). The concentrations of tilmicosin in DS and BAL samples exceeded plasma drug concentrations by 567 ± 189% and 776 ± 1138%, respectively. The enrofloxacin/ciprofloxacin concentrations collected by DS were significantly different than those collected by BAL, but the tilmicosin concentrations were not significantly different between the two methods. Concentrations of enrofloxacin/ciprofloxacin exceeded the MIC values for bovine respiratory disease pathogens but tilmicosin did not reach MIC levels for these pathogens in any fluids. 相似文献
843.
Single layer centrifugation of fresh dromedary camel semen improves sperm quality and in vitro fertilization capacity compared with simple sperm washing
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![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
C Malo EG Crichton JM Morrell BS Pukazhenthi JA Skidmore 《Reproduction in domestic animals》2017,52(6):1097-1103
Single layer centrifugation (SLC) through a colloid is a tool for selecting viable mammalian spermatozoa but has not been used previously for fresh dromedary camel sperm. Semen from six camels (2 ejaculates/male) was diluted 1:5 (v:v) or 1:10 (v:v) in a Tris–citrate–fructose buffer for mechanical liquefaction by gentle pipetting. Following liquefaction, semen was processed either by SLC or by centrifugation without a colloid (control). Total and progressive motilities, CASA kinematics, vitality and acrosome integrity (eosin–nigrosin) and plasma membrane integrity (Hypo‐osmotic swelling test; HOST), and fertilizing ability in a heterologous assay (zona‐free goat oocytes) were evaluated. Both total (p = .003) and progressive motilities (p = .003) were higher in SLC‐processed than in control semen samples, irrespective of dilution. Positive HOST values increased when using colloid in 1:5 (p = .001) and 1:10 dilution (p = .010). Colloid‐selected sperm had higher penetration rates than controls (p < .001 and p = .02 for 1:5 and 1:10 dilutions, respectively). However, only the SLC sperm at 1:5 dilution showed higher percentages of pronuclear formation (p = .02) than controls. Dilution effect was only significant for total motility before in vitro fertilization, with higher values for the 1:5 dilution (p = .033). The recovery rates of motile sperm between dilutions were similar (26.1% vs 35.4%; p = .226). In conclusion, SLC is a promising tool for selecting functional dromedary camel sperm and warrants more research. 相似文献
844.
S. Y. Liu Z. Liu B. D. L. Fitt N. Evans S. J. Foster † Y. J. Huang A. O. Latunde-Dada J. A. Lucas 《Plant pathology》2006,55(3):401-412
Effects of pretreatment of Brassica napus leaves with ascospores of Leptosphaeria biglobosa or chemical defence activators [acibenzolar- S -methyl (ASM) or menadione sodium bisulphite (MSB)] on infection by ascospores of Leptosphaeria maculans (phoma stem canker) and development of disease were studied in controlled-environment (phoma leaf spot) and field (phoma leaf spot and stem canker) experiments. In controlled-environment experiments, pretreatment of oilseed rape leaves (cv. Madrigal) with L. biglobosa , ASM or MSB delayed the appearance of L. maculans phoma leaf spot lesions. These pretreatments also decreased the phoma leaf spot lesion area in both pretreated leaves (local effect) and untreated leaves (systemic effect). In winter oilseed rape field experiments in the 2002/03 and 2003/04 growing seasons, pretreatment with L. biglobosa or ASM in October/November decreased not only the number of phoma leaf spot lesions per leaf caused by L. maculans in autumn/winter, but also the severity of phoma stem canker in the subsequent spring/summer. Effects were greater in 2002/03 (when natural L. maculans ascospore release began in September 2002) than in 2003/04 (when ascospore release began in December following a period of dry weather in August/September 2003). These results suggest that pretreatment with biological or chemical defence activators can induce local and systemic resistance to L. maculans , with both short-term effects on the development of phoma leaf spotting and long-term effects on the development of stem canker 8 months later. 相似文献
845.
Aravind K. Jukanti Phil L. Bruckner Debra K. Habernicht Curt R. Foster John M. Martin Andreas M. Fischer 《Cereal Chemistry》2003,80(6):712-716
Polyphenol oxidases (PPOs) from several plant species, including wheat, have been implicated in undesirable brown discolorations of food products. It has been demonstrated that these enzymes are often present in a latent form or are membrane‐associated, necessitating detergent or other treatments to obtain fully active preparations. Here, the influence of different detergents on wheat meal and flour PPOs was investigated. Extraction in presence of 50 mM SDS led to a 5‐ to 15‐fold increase in PPO activity, making quantitative assays in flour from low‐PPO lines more robust. Among a series of additional nonionic, anionic, and cationic detergents tested, only n ‐lauroylsarcosine increased extractable PPO activity to a degree comparable to that of SDS. Additional experiments suggested that a large fraction of wheat meal PPOs may be membrane‐associated and that SDS is able to activate PPOs extracted from high‐activity but not from low‐activity wheat lines. PPO activities assayed after SDS extraction of meal and flour were highly correlated with each other and with activity determined in whole (intact) kernels in absence of SDS. Correlation coefficients between PPO activities measured with all these methods and noodle brightness were about equal, indicating that activities assayed after SDS extraction are useful for germplasm screening and quality prediction. 相似文献