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81.
The concentrations of chloramphenicol and its water-soluble metabolites in the plasma of six clinically healthy heifers were measured at intervals during five days after intramuscular administration of free chloramphenicol (20 mg/kg) in a vehicle containing 40% of an organic solvent. Estimations were carried out by a colorimetric method and by high pressure liquid chromatography (for the very low values beyond the second day).For free chloramphenicol a peak concentration of 1.7 g/ml at 7.3 h after injection was found (MIC: 5 g/ml). Bioavailability was calculated to be 63%.It is shown that absorption was apparently not a uniform process but occurred rather slowly (t1/2(ab)=10.2 h) for the main part of the available dose, whereas one sixth was quickly absorbed (t1/2(ab)=0.7 h). The apparent half-time of elimination was 10.2 h for the unchanged drug. At the fifth day after administration the plasma concentration was below the limit of detectability (10 ng/ml) in all animals. 相似文献
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This report describes the presenting signs, biochemical abnormalities, and radiographic changes in a 4-month-old kitten with vitamin D-dependent rickets type 2. Details of therapy are described and possible reasons for treatment failure are discussed. 相似文献
84.
The equine industries in Ireland are vibrant and growing. They are broadly classified into two sectors: Thoroughbred racing, and sports and leisure. This paper describes these sectors in terms of governance, education and training in equine welfare, and available data concerning horse numbers, identification, traceability and disposal. Animal welfare, and specifically equine welfare, has received increasing attention internationally. There is general acceptance of concepts such as animal needs and persons' responsibilities toward animals in their care, as expressed in the 'Five Freedoms'. As yet, little has been published on standards of equine welfare pertaining to Ireland, or on measures to address welfare issues here. This paper highlights the central role of horse identification and legal registration of ownership to safeguard the health and welfare of horses. 相似文献
85.
Connolly Dj Dwyer P Fagan J Hayes M Ryan E Costello E Kilroy A More S 《Irish veterinary journal》2008,61(8):533-537
Tuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected. 相似文献
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88.
G. Amanuel R. F. Kühne D. G. Tanner P. L. G. Vlek 《Biology and Fertility of Soils》2000,32(5):353-359
N2 fixation by leguminous crops is a relatively low-cost alternative to N fertilizer for small-holder farmers in developing
countries. N2 fixation in faba bean (Vicia faba L.) as affected by P fertilization (0 and 20 kg P ha–1) and inoculation (uninoculated and inoculated) with Rhizobium leguminosarium biovar viciae (strain S-18) was studied using the 15N isotope dilution method in the southeastern Ethiopian highlands at three sites differing in soil conditions and length of
growing period. Nodulation at the late flowering stage was significantly influenced by P and inoculation only at the location
exhibiting the lowest soil P and pH levels. The percentage of N derived from the atmosphere ranged from 66 to 74%, 58 to 74%
and 62 to 73% with a corresponding total amount of N2 fixed ranging from 169 to 210 kg N ha–1, 139 to 184 kg N ha–1 and 147 to 174 kg N ha–1 at Bekoji, Kulumsa and Asasa, respectively. The total N2 fixed was not significantly affected by P fertilizer or inoculation across all locations, and there was no interaction between
the factors. However, at all three locations, N2 fixation was highly positively correlated with the dry matter production and total N yield of faba bean. Soil N balances
after faba bean were positive (12–58 kg N ha–1) relative to the highly negative N balances (–9–44 kg N ha–1) following wheat (Triticum aestivum L.), highlighting the importance of rotation with faba bean in the cereal-based cropping systems of Ethiopia.
Received: 13 January 2000 相似文献
89.
Soil organic phosphorus dynamics following perturbation of litter cycling in a tropical moist forest 总被引:1,自引:0,他引:1
The productivity of tropical lowland moist forests is often considered to be limited by the availability of phosphorus. Organic phosphorus is often abundant in tropical soils, but its role in forest nutrition is largely unknown. We addressed this by using a large-scale litter manipulation experiment to investigate the stability of soil organic phosphorus in a tropical lowland forest in Central Panama. Three years of litter removal reduced the organic phosphorus concentration in the surface 2 cm of mineral soil by 23%, as determined by NaOH-EDTA extraction and 31 P-NMR spectroscopy; this included decreases in phosphate monoesters (20%) and DNA (30%). Three years of litter addition (equivalent to adding 6 kg P ha–1 per year) increased soil organic phosphorus by 16%, which included a 31% increase in DNA. We did not detect higher-order inositol phosphates, despite their abundance in mineral soils of temperate ecosystems. Our observed turnover rate suggests that even the 0–2-cm layer of the mineral soil contributes a fifth of the total phosphorus needed to sustain above-ground growth in this forest. Soil organic phosphorus is thus likely to make a more important contribution to the nutrition of semi-evergreen forest plants than has hitherto been acknowledged. 相似文献
90.
Louise Katherine BARTOLAC Jenna Louise LOWE George KOUSTAS Cecilia SJ?BLOM Christopher Gerald GRUPEN 《The Journal of reproduction and development》2015,61(6):525-531
The aim of this study was to determine the optimum conditions for vitrifying in vitro
produced day 7 porcine embryos using different vitrification devices and blastocoele collapse methods. Firstly
embryos were collapsed by micro-pipetting, needle puncture and sucrose with and without conducting
vitrification. In the next experiment, non-collapsed embryos were vitrified in an open device using either
superfine open-pulled straws (SOPS) or the CryoLoopTM system, or vitrified in a closed device using
either the CryoTipTM or Cryo BioTM’s high security vitrification system (HSV). The
post-thaw survival of embryos vitrified in the open devices did not differ significantly (SOPS: 37.3%;
CryoLoopTM: 37.3%) nor did the post-thaw survival of embryos vitrified in the closed devices
(CryoTip™: 38.5%; HSV: 42.5%). The re-expansion rate of embryos that were collapsed via micro-pipetting
(76.0%) did not differ from those that were punctured (75.0%) or collapsed via sucrose (79.6%) when
vitrification was not performed. However, embryos collapsed via sucrose solutions (24.5%) and needle puncture
(16.0%) prior to vitrification were significantly less likely to survive vitrification than the control
(non-collapsed) embryos (53.6%, P < 0.05). The findings show that both open and closed vitrification
devices were equally effective for the vitrification of porcine blastocysts. Collapsing blastocysts prior to
vitrification did not improve survival, which is inconsistent with the findings of studies in other species.
This may be due to the extremely sensitive nature of porcine embryos, and/or the invasiveness of the
collapsing procedures. 相似文献