全文获取类型
收费全文 | 510篇 |
免费 | 42篇 |
国内免费 | 1篇 |
专业分类
林业 | 8篇 |
农学 | 3篇 |
基础科学 | 5篇 |
17篇 | |
综合类 | 129篇 |
农作物 | 27篇 |
水产渔业 | 13篇 |
畜牧兽医 | 318篇 |
园艺 | 7篇 |
植物保护 | 26篇 |
出版年
2019年 | 6篇 |
2017年 | 8篇 |
2016年 | 17篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 19篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 6篇 |
2009年 | 8篇 |
2008年 | 19篇 |
2007年 | 16篇 |
2006年 | 19篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1995年 | 8篇 |
1993年 | 7篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1976年 | 5篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 10篇 |
1971年 | 6篇 |
1970年 | 8篇 |
1969年 | 5篇 |
1967年 | 9篇 |
1966年 | 5篇 |
1963年 | 6篇 |
1960年 | 4篇 |
1939年 | 4篇 |
排序方式: 共有553条查询结果,搜索用时 250 毫秒
1.
While isotopic techniques have largely superseded traditional markers for the determination of the volume of fluid compartments in vivo, they are not always convenient, especially with diarrhoeic animals. A direct comparison was therefore made in week-old calves between Evans blue and radio-iodinated serum albumin as measures of plasma volume and thiocyanate or 24sodium as measures of extracellular fluid space. The correlation coefficients were excellent (1.00, 0.96; P < 0.001) and the calves had plasma and extracellular fluid volumes of 72 +/- 2 and 438 +/- 2 ml kg-1, respectively. The latter value is, though high, typical of young animals and comparable with other data in calves. 相似文献
2.
3.
van den Oord QG van Wijk EJ Lugton IW Morris RS Holmes CW 《New Zealand veterinary journal》1995,43(7):328-332
Two groups of six mature brushtail possums (Trichosurus vulpeculu) were housed in two respiration chambers, and their heat production, whole body conductance and lower critical temperatures were measured under a variety of simulated weather patterns. The possums were subjected to ambient temperatures of 30, 20 and 3 degrees C. At 20 and 3 degrees C, the animals were exposed to near still air and light winds (wind speed 0.8 and 6.7 km/h), both with, and without, simulated rain every 8 hours. The lower critical temperature in near still air lies between 7 and 10 degrees C. This temperature increases by about 2, 6 and 8 degrees C respectively for a wind velocity of 6.7 km/h, simulated rain and a combination of the two factors. Weather in New Zealand, especially in the cooler part of the year, will often produce conditions below the lower critical temperature of the thermoneutral zone of possums. This will necessitate significant increases in metabolic rate and hence food consumption or mobilisation of body fat reserves, which if not sustainable will result in the death of possums. Field studies have shown that this is often the case in the wild. It is proposed that this stress may be sufficient to decrease the resistance (especially cell-mediated immunity) of some possums and allow acceleration of the disease process in those infected with Mycobacterium bovis. 相似文献
4.
1. The performance of six commercial stocks of laying hens fed on a diet composed of home‐produced foodstuffs, not usually used for human consumption, was compared with that of birds fed on a conventional diet.
2. The experimental diet was calculated to be low in energy and methionine and high in fibre by conventional standards. Birds ate up to 12% more of this diet, but the calculated intakes of energy and methionine were less than those of the corresponding controls.
3. White stocks fed on the experimental diet produced seven eggs less per bird than controls while the production of brown stocks was essentially unaffected.
4. The gross efficiency of energy utilisation for egg production was better with the experimental diet. 相似文献
5.
The ability of nine strains of avian infectious bronchitis virus (IBV) to induce chicken interferon has been investigated using Semliki Forest virus for the tests. The Beaudette, H120 and Connecticut 46 strains induced interferon in the allantoic fluids of embryonated hens' eggs, the highest titre (1 : 30) being associated with Beaudette; but these as well as the Massachusetts M-41 and H52 strains failed to yield interferon in primary monolayer cultures of chick kidney cells as did all nine strains in organ cultures of chick embryo trachea. None of six strains of IBV investigated was susceptible to the inhibitory effects of chicken interferon. 相似文献
6.
Morphological, cytological and molecular evidence is presented which confirms that the frosty pod rot pathogen of cocoa, formerly classified as the mitosporic fungus Moniliophthora roreri (Deuteromycota), belongs to the hymenomycetous genus Crinipellis (Basidiomycota) and that two varieties should now be recognized: Crinipellis roreri var. roreri and the new variety C. roreri var. gileri . The latter was collected on Theobroma gileri , an endemic tree of submontane forests in north-west Ecuador, and can be distinguished from Ecuadorian and Peruvian isolates from cocoa ( T. cacao ) on the basis of spore morphology, incompatibility and nucleotide sequence data. As with var. roreri , meiosis is shown to occur within the dispersive and infective spore stage of var. gileri and these meiospores are interpreted to represent a much modified probasidium. In addition, in a field inoculation experiment, an isolate from T. gileri proved to be noninfective to cocoa pods when compared with positive control strains isolated from T. cacao in western Ecuador and T. bicolor in eastern Ecuador. It is concluded that var. gileri is the vestigial progenitor of the frosty pod rot pathogen of cocoa, with a host range and distribution restricted to T. gileri in the mesic forests of north-west South America. 相似文献
7.
Imerslund-Gräsbeck syndrome is an autosomal recessive disease reported only in certain pure-breed dogs. An 18-month-old, male neutered beagle cross-breed was presented for evaluation of severe lethargy, progressive weakness and anorexia. Main clinicopathological findings included low body condition score (2.5/9), severe muscle atrophy, several neurological abnormalities, mild normochromic, normocytic, non-regenerative anaemia, severe hypocobalaminemia and mild proteinuria. Extensive diagnostic tests ruled out most of differential diagnoses for the aforementioned clinicopathological abnormalities and genetic evaluation showed that the dog was heterozygous for two previously described mutations affecting the CUBN gene, the beagle and the border collie variants. The dog showed an excellent clinical response to oral cobalamin supplementation with no relapse after 4 months. In conclusion, this case creates awareness that Imerslund-Gräsbeck syndrome should be considered even in mixed-breed dogs with compatible clinical signs and that two different pathogenic CUBN mutations in compound heterozygosity can lead to a typical Imerslund-Gräsbeck syndrome phenotype. 相似文献
8.
Andrea Weissman Mauricio Solano Olivier Taeymans Shannon P. Holmes David Jiménez Bruce Barton 《Veterinary radiology & ultrasound》2016,57(2):124-129
An imaging report is a vital communication tool between a radiologist and clinician. In a field where in‐person communication may not be readily available, it is imperative that the report clearly relays pertinent clinical information in a timely manner. The purpose of this observational study was to describe and compare opinions and expectations of small animal general practitioners, veterinary specialists, and veterinary radiologists regarding the imaging report. Online surveys were distributed, and data were collected from 202 veterinary clinicians and 123 veterinary radiologists. The majority (89%) of clinicians were satisfied with their imaging reports and stated that they read the radiology report as soon as it was available (92%). Just less than half (48%) of clinicians indicated it was standard of care that a board‐certified veterinary radiologist read all imaging studies. Radiologists and clinicians agreed that a clinical history (98% and 94%, respectively) and clinical question (82% and 68%, respectively) were needed to generate a good radiology report. Fifty‐five percent to 70% of clinicians prefer red bulleted reports, which included incidental findings (96%); while radiologists slightly favored prose reporting (37–46%). Clinicians found it helpful when additional imaging (86%), medical (71%), and surgical recommendations (73%) were made. About one‐third of specialists who had been in practice for >11 years thought they were better able to interpret imaging for their own specialty than the radiologist. Clinicians voiced discontentment with reports that were not completed in a timely manner or did not give a prioritized differential list. Further studies are warranted to provide a more in‐depth evaluation of veterinary radiology reporting structure and style. 相似文献
9.
10.
CASE HISTORY: A group of 32 Friesian and four Hereford calves, 3–4 months old with body weights between 100–120?kg, were purchased from a weaner sale. On arrival at the property the Hereford calves were treated with a combination anthelmintic containing 2?g/L abamectin and 80?g/L levamisole hydrochloride. Shortly afterwards they developed tremors and frothing from the mouth, and two died overnight. The Friesian calves were treated with the same anthelmintic on the following day, when some showed hypersalivation and frothing from the mouth.CLINICAL FINDINGS: Examination of the three most severely affected Friesian calves revealed severe nicotinic-type symptoms including hypersalivation, frothing from the mouth, muscle tremors, recumbency, rapid respiration, hyperaesthesia, and central nervous system depression. Other calves showed mild to moderate signs of intoxication including restlessness, tail switching, salivation, tremors, frequent defaecation, mild colic and jaw chomping. Two calves died shortly afterwards. An adverse drug event investigation revealed that the formulation and quality of the anthelmintic was within the correct specification, and that the drench gun was functioning correctly.DIAGNOSIS: Suspected levamisole intoxication due to a combination of possible overdosing, dehydration, and stress caused by transportation and prolonged yarding.CLINICAL RELEVANCE: Susceptibility to levamisole toxicity in New Zealand calves can be increased if factors like dehydration or stress are present. Levamisole has a narrow margin of safety, and overdosing in calves can easily occur if the dose rate is not based on their actual weight or health status. 相似文献