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71.
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Norgestrel treatment of boars differed from analogous chloromandinone acetate treatment in that no significant morphokinetic effect was recordable from all parts of the hypothalamic-adenohypophyseal-gonadal axis. The morphometric parameters as well as the histological pattern obtained of the anterior lobe of the pituitary gland appear to prove that in boar the antigonadotropic effect of norgestrel is lower than that of chloromadinone acetate, with dosage and duration of treatment identical.  相似文献   
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In this paper, multilevel logistic models which take into account the multilevel structure of multi-site pig production were used to estimate the variances between pigs produced in Danish multi-site pig production facilities regarding seroconversion to Actinobacillus pleuropneumoniae serotype 2 (Ap2) and Mycoplasma hyopneumoniae (Mh). Based on the estimated variances, three newly described computational methods (model linearisation, simulation and linear modelling) and the standard method (latent-variable approach) were used to estimate the correlations (intra-class correlation components, ICCs) between pigs in the same production unit regarding seroconversion. Substantially different values of ICCs were obtained from the four methods. However, ICCs obtained by the simulation and the model linearisation were quite consistent. Data used for estimation were collected from 1161 pigs from 429 litters reared in 36 batches at six Danish multi-site farms chronically infected with the agents. At the farms, weaning age was 3-4.5 weeks, after which batches of pigs were reared using all-in/all-out management by room. Blood samples were collected shortly before: weaning, transfer from weaning-site to finishing-site, and sending the first pigs in the batch for slaughter (third sampling). Few pigs seroconverted at the weaning-sites, whereas considerable variation in seroconversion was observed at the finishing-sites. Multilevel logistic models (initially including four levels: farm, batch, litter, pig) were used to decompose the variation in seroconversion at the finishing-site. However, there was essentially no clustering at the litter level-leading to the use of three-level models. In the case of Ap2, clustering within batch was so high that the data eventually were reduced to two levels (farm, batch). For seroconversion to Ap2, ICC between pigs within batches was approximately 90%, whereas the ICC between pigs within batches for Mh was approximately 40%. This indicates that the possibility for Mh to spread between pigs within batches is lower than for Ap2. The diversity in seroconversion between batches within the same farm was large for Ap2 (ICC approximately 10%), whereas there was a relative strongly ICC (approximately 50%) between batches for Mh. This indicates that the transmission of Mh is more consistent within a farm, whereas the presence of Ap2 varies between batches within a farm.  相似文献   
76.
Enzootic calcinosis was diagnosed in 16 cows, which originated from 6 dairy farms located in the Unterengadin valley in Switzerland between 1,402 and 1,650 metres above sea level. During the winter, the cows were fed haylage, which contained up to 50 per cent golden oat-grass (Trisetum flavescens), and hay and grain. The first symptoms of enzootic calcinosis were noted in March 1998, when some of the cows developed locomotor abnormalities. Additional cases were diagnosed during the following three months. The most important clinical findings were decreased milk production, weight loss, frequent recumbency, difficulty in rising, kneeling while rising and feeding, stilted gait, arched back, shifting weight from one foot to another and reluctance to remain standing after being roused. Of the 16 cows, 5 had elevated concentrations of serum calcium and 10 had decreased concentrations of serum magnesium. All cows had normal or decreased concentrations of serum phosphorus, because the feeding of haylage containing golden oat-grass had been discontinued two months previously. In all of the cows, the most important postmortem findings were severe calcification of the aorta, iliac artery, brachiocephalic trunk and pulmonary artery.  相似文献   
77.
After several thousand sheep had been imported from Australia and New Zealand to Croatia during 1995, many native sheep that had been in contact with the imported animals acquired a severe ocular disease closely resembling infectious keratoconjunctivitis. In affected flocks glucose-fermenting mycoplasma were isolated from 48 per cent of conjunctival swabs and Branhamella ovis from 58 per cent. Twelve of 42 culturally and biochemically identical isolates were identified as Mycoplasma conjunctivae by polymerase chain reaction. From the conjunctivae of two animals M conjunctivae and M arginini were isolated in mixed culture. For many reasons most farmers removed the imported animals from their flocks and only sporadic cases of the disease were recognised in 1996. At the end of 1997, six flocks which were clinically free of the disease but had been affected during 1995, and five flocks with no history of the severe ocular disease were examined clinically and microbiologically, and were found to be free of M conjunctivae infection. At the time, B ovis was cultured almost exclusively from sheep originating from flocks which had been affected during 1995 and/or 1996. It was usually isolated in pure culture or as the predominant bacterial species, and was often accompanied by mild conjunctivitis. There were no microbiologically confirmed new cases of infectious keratoconjunctivitis during 1998 and 1999.  相似文献   
78.
伍红  平淑珍  KA Malik  林敏 《核农学报》2000,14(5):305-310
粪产碱菌A1 5 0 1能在氯化钠浓度高达 4%的固体和液体介质中良好生长 ,合成IAA和固定空气中的氮素。当氯化钠浓度超过 3 %时 ,A1 5 0 1丧失运动和趋化能力。一定盐浓度胁迫下A1 5 0 1能定殖在水稻根表和根毛区和侧根伸出部位 ,表现出较高的联合固氮活性。0 5 %的氯化钠能促进A1 5 0 1在水稻根表的定殖能力。A1 5 0 1能通过侧根伸出部位侵入根内。  相似文献   
79.
Prevention of edema disease in pigs by passive immunization.   总被引:4,自引:0,他引:4       下载免费PDF全文
The effect of treatment with verotoxin 2e (VT2e) specific antiserum was evaluated in 3 Danish pig herds with edema disease (ED). The antiserum was prepared by immunizing horses with a VT2e toxoid. The study was performed as a randomized blind field trial with parallel treatment and control groups. There were approximately 50 piglets in each group in each of the 3 herds and 741 piglets were included in the study (244 from herd A, 249 from herd B, and 247 from herd C). Treatment groups received 2, 4, or 6 mL anti-VT2e serum intramuscularly the day before weaning. Control groups were treated with 6 mL normal horse serum or 6 mL RPMI 1640 medium as placebo. All pigs that died in the trial period (1 d before weaning to 44 d after weaning) were examined pathologically and microbiologically. Mortality due to ED, mortality due to other causes, and adverse effects due to treatment were recorded. As there was no mortality due to ED, herd B was excluded from statistical calculations on mortality. The content of horse antibodies specific to VT2e in serum from pigs was analyzed in an indirect ELISA. A higher dose of anti-VT2e serum was reflected in higher optical density values in the indirect ELISA. Transient adverse reactions, seen as vomiting, ataxia, and cyanosis, occurred shortly after the injection of horse serum in 1.5% of the pigs, and one pig died. There were no statistically significant differences in mortality due to other causes among the 3 treatment groups in herds A and C. Only pigs from which F18+, VT2e+, ST-, LT- hemolytic E. coli (0139 or O-rough) was isolated were diagnosed as dead due to ED. Deaths due to ED in the control groups were 8.1% and 12.0% in herds A and C, respectively, compared with 0% and 0.7% in the corresponding serum groups. The difference between treatment and control groups was statistically significant (P<0.0001). It was not possible to establish an effect of dose (2, 4, or 6 mL) of anti-VT2e serum, because only one pig died of ED in the treatment groups. It was concluded that passive immunization by intramuscular injection of a VT2e-specific antiserum can be used for protecting piglets against ED.  相似文献   
80.
We live in an age defined in large part by various facets of neoliberalism. In particular, the market world has impinged on virtually every aspect of food and agriculture. Moreover, most nation-states and many international governance bodies incorporate aspects of neoliberal perspectives. Multi-stakeholder initiatives (MSIs), with their own standards, certifications, and accreditations are evidence of both the continuing hegemony of neoliberalism as well as various responses to it. Importantly, to date even attempts to limit neoliberal hegemony through MSIs have been largely within the parameters established by those same neoliberal agendas. However, neoliberalism is itself in crisis as a result of climate change, the continuing financial crisis, and rising food prices. The founding myths of neoliberalism are still widely held, having the effect of closing off alternative paths to the future. Yet, this need not be the case. Alternatives to the current MSIs that promote justice, democracy, and equality can still be constructed.  相似文献   
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