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71.
As well as H5 highly pathogenic avian influenza viruses (HPAIV), H7 HPAIV strains have caused serious damages in poultry industries worldwide. Cases of bird-to-human transmission of H7 HPAIV have also been reported [11]. On the outbreak of avian influenza, rapid diagnosis is critical not only for the control of HPAI but also for human health. In the present study, a rapid diagnosis kit based on immunochromatography for the detection of H7 hemagglutinin (HA) antigen of influenza A virus was developed using 2 monoclonal antibodies that recognize different epitopes on the H7 HAs. The kit detected each of the tested 15 H7 influenza virus strains and did not react with influenza A viruses of the other subtypes than H7 or other avian viral and bacterial pathogens. The kit detected H7 HA antigen in the swabs and tissue homogenates of the chickens experimentally infected with HPAIV strain A/chicken/Netherlands/2586/03 (H7N7). The results indicate that the present kit is specific and sensitive enough for the diagnosis of HPAI caused by H7 viruses, thus, recommended for the field application as a pen-site test kit.  相似文献   
72.
The present work was conducted to study the comparative efficacy of two anti-protozoan (babesicidal) drugs on the recovery and health of horses. A total of 80 horses, showing typical clinical symptoms of the disease, were selected for this study; the presence of babesiosis was confirmed through blood smear examination. These animals were divided into two groups i.e. A and B. Horses of Group A, were treated with diminazene diaceturate, while horses of Group B were treated with diminazene aceturate. Efficacy of the drugs was determined by the reversal of clinical signs and a negative blood smear examination. The efficacy of diminazene diaceturate was demonstrated to be 80% while diminazene aceturate was found to have 90% efficacy against babesiosis.  相似文献   
73.
The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year, stale seedbed preparations followed by weed control prior to planting reduced the amount of weeds during crop growth by 43–83%. Control of the emerged seedlings after a stale seedbed preparation was more effective with glyphosate than with a rotary harrow. Covering the rotary harrow during control to prevent light reaching the soil improved its effect on the weed density during crop growth in two of 3 years. Radiation with far red light (FR) did not reduce the number of emerging weeds in this study. Mechanical control by finger weeder, torsion weeder and hoe was applied without stale seedbed preparations. These measures reduced the weed densities by 88–99%, compared with the untreated control and were more effective than chemical weed control with carbetamide and chlorpropham. The results show that the stale seedbed technique in combination with mechanical control of emerging weeds can reduce the weed population during crop growth as effectively as chemical control. The technique may therefore help reduce the use of herbicides in lettuce crops in the future.  相似文献   
74.
The ethanol extract of P. kamstchandalis as well as ethyl haematommate, ethyl-2,4-dihydroxy-6-methylbenzoate and methyl-β-orsellinate isolated from it exhibited varying degrees of antibacterial activity.  相似文献   
75.
Fisheries Science - Fisheries subsidies have attracted considerable attention worldwide since the 1990s. The World Trade Organization (WTO), among others, started to strengthen its disciplines in...  相似文献   
76.
For many commercial fisheries, reductions in fishing effort would likely result in higher long-term catches and improved incomes per fisherman. But fishing licenses are perceived as though they were property rights, which can imply relatively high costs for publicly funded buyback programmes to reduce fishing effort. Instead of the public buying out fishing licenses, it can make good business sense for license holders to expect the public to pay for protection against new licenses, and to proceed under this protection to finance buybacks of licenses themselves. The short-run costs of such an investment are outweighed by long-term gains in annual incomes and the transfer value of licenses at the time of individual retirement, especially in fisheries that are severely overfished.  相似文献   
77.
The combination of a rising population and increased food demand has placed tremendous pressure on the land resources of Bangladesh. These pressures are exacerbated by the annual wet-season floods which frequently devastate much of the agricultural land. Successive governments have therefore sought international aid to assist in the development of flood control measures. Of particular importance are 14 major schemes which aim to provide protection from 20–25 year return floods by the construction of earth-embanked enclosures. There is no doubt that these schemes have been very successful in protecting valuable agricultural areas from floods and hence increasing agricultural production. There is, however, growing evidence from a range of sources for long-term deterioration in soil fertility within the project areas. The study reported here is the first to systematically examine the changes taking place in soil properties following the establishment of a flood control, drainage and irrigation project. Comparison of two soil series, sampled from within and without the project area, demonstrate that within six years of project establishment, significant adverse changes have occurred in several soil properties; these include increasing acidity and a decline in available nutrients. The changes are attributable to a combination of poor management strategies and the absence of the annual flood input of silt. As Bangladesh cannot afford any decline in agricultural output, it is vital to establish whether adverse changes recorded here are occurring in other projects. This can be achieved by the establishment of a nationwide programme of soil fertility monitoring. © 1998 John Wiley & Sons, Ltd.  相似文献   
78.
79.
In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut-3 and Glut-5 and the zona pellucida binding protein As-A (P68) in three different steps of the freezing-thawed protocol: at 17°C (fresh BTS-diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post-thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post-pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut-3 maintains the expression in the acrosome region post-thawing but not along the tail where is reduced. The expression of Glut-5 and As-A is majority located at the post-acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut-3 and Glut-5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival.  相似文献   
80.
In swine, the use of frozen-thawed (FT) sperm for artificial insemination (AI) is limited because of poor sow fertility, possibly associated with a post-thaw capacitation-like status resulting in fewer fully viable sperm. Sow fertility to AI with FT sperm may improve with deeper deposition of sperm within the female tract, insemination very close to ovulation, or reversal of cryocapacitation by seminal plasma (SP). We performed two experiments to examine these suggestions. In experiment 1, 122 multiparous Yorkshire sows received 600 IU equine chorionic gonadotrophin at weaning and 5 mg pLH 80 h later to control time of ovulation. The predicted time of ovulation (PTO) was 38 h after pLH injection. Thereafter, sows were assigned on the basis of parity to a single AI of FT sperm at 2 h before PTO, or at 12 h before PTO, or FT sperm supplemented with 10% SP at 12 h before PTO. Control sows received fresh semen at 12 h before PTO. All semen doses were adjusted to 3 x 10(9) live cells and deposited into the cervix. Experiment 2 employed 99 multiparous crossbred sows and repeated the treatments of experiment 1 except that all FT inseminations were intrauterine. In both experiments, farrowing rates were lower (p < 0.01) following FT inseminations with no effect of time of insemination or of supplemental SP. In experiment 1, litter size was smaller following FT insemination (p < 0.05), but no effect on litter size was evident in experiment 2. Supplemental SP had no effect on litter size in either experiment. The lack of effect of either SP or timing of FT insemination on sow fertility suggests that the non-lethal sperm cryoinjury affecting fertility involves more than just cryocapacitation.  相似文献   
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