全文获取类型
| 收费全文 | 154295篇 |
| 免费 | 8860篇 |
| 国内免费 | 265篇 |
专业分类
| 林业 | 6125篇 |
| 农学 | 4796篇 |
| 基础科学 | 1172篇 |
| 19021篇 | |
| 综合类 | 26285篇 |
| 农作物 | 5976篇 |
| 水产渔业 | 8251篇 |
| 畜牧兽医 | 78761篇 |
| 园艺 | 2040篇 |
| 植物保护 | 10993篇 |
出版年
| 2018年 | 2155篇 |
| 2017年 | 2399篇 |
| 2016年 | 2217篇 |
| 2015年 | 1935篇 |
| 2014年 | 2369篇 |
| 2013年 | 6013篇 |
| 2012年 | 4465篇 |
| 2011年 | 5471篇 |
| 2010年 | 3380篇 |
| 2009年 | 3392篇 |
| 2008年 | 5228篇 |
| 2007年 | 4989篇 |
| 2006年 | 4739篇 |
| 2005年 | 4406篇 |
| 2004年 | 4303篇 |
| 2003年 | 4264篇 |
| 2002年 | 4118篇 |
| 2001年 | 4855篇 |
| 2000年 | 4695篇 |
| 1999年 | 3821篇 |
| 1998年 | 1507篇 |
| 1997年 | 1532篇 |
| 1996年 | 1431篇 |
| 1995年 | 1789篇 |
| 1994年 | 1604篇 |
| 1993年 | 1537篇 |
| 1992年 | 3181篇 |
| 1991年 | 3309篇 |
| 1990年 | 3350篇 |
| 1989年 | 3360篇 |
| 1988年 | 3077篇 |
| 1987年 | 3168篇 |
| 1986年 | 3246篇 |
| 1985年 | 3115篇 |
| 1984年 | 2624篇 |
| 1983年 | 2324篇 |
| 1982年 | 1584篇 |
| 1981年 | 1482篇 |
| 1980年 | 1436篇 |
| 1979年 | 2331篇 |
| 1978年 | 1926篇 |
| 1977年 | 1633篇 |
| 1976年 | 1455篇 |
| 1975年 | 1546篇 |
| 1974年 | 2082篇 |
| 1973年 | 2104篇 |
| 1972年 | 2061篇 |
| 1971年 | 1828篇 |
| 1970年 | 1721篇 |
| 1969年 | 1578篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
991.
F Madec C Kaiser J M Gourreau F Martinat-Botte 《Comparative immunology, microbiology and infectious diseases》1989,12(1-2):17-27
Pathological consequences of a severe outbreak of swine influenza (H1N1 virus) in the non immune sow at the beginning of pregnancy, under natural conditions. A sudden acute outbreak of fever, depression, anorexia and coughing in a group of nulliparous sows from a herd that was currently under epidemiological investigation lead to build a particular disposal of observation. The clinical signs were daily recorded including rectal temperature. Blood was taken from the sows at the beginning of the troubles and 3 weeks later for the detection of Aujesky's disease, coronavirus TGE-like, Influenza viruses A/H1N1 and A/H3N2 and Mycoplasma hyopneumoniae. Viral detection was attempted from nasal swabs and aborted fetuses during the acute phase. The clinical study showed fever reaching near 41 degrees C on most of the pigs and lasting usually from 2 to 5 days. The diagnosis of Influenza (virus swine H1N1) was established both on serology (massive seroconversion) and on the detection of the virus from the nasal swabs and from an aborted fetus. The control of the lungs of sows "not in pig" and culled showed extended lesions of bronchopneumonia and Pasteurella multocida was found. The technical consequences of this severe outbreak of Influenza on reproduction were mainly important at the beginning of pregnancy. Over 13 sows inseminated less than 1 week before the outbreak, only 3 farrowed (respectively 5.5 and 12 piglets); 7 returned to oestrus and 3 "not a pig" at 21 days (echotomography) did not show signs of heat and were culled. Over 8 pregnant sows (1 month of pregnancy), 6 farrowed normal litters and total embryonic resorption occurred in 2 sows. Over 18 pregnant sows (more than 45 days gestation) one aborted. 相似文献
992.
Thurley J 《New Zealand veterinary journal》1989,37(1):30-31
A 3 year old Boxer dog was presented with a history of syncope and an irregular heart heat. An arrhythmia characterised by ventricular premature contractions was detected and was thought to cause the syncopal episodes. On the basis of the age, breed and the characteristic electrocardiographic findings, a diagnosis of Boxer Cardiomyopathy was made. The dog was treated with procainamide 500 mg every 8 hours to control the arrythmia and there were no further syncopal episodes in the subsequent 13 months. 相似文献
993.
Viruses and virus-like particles detected during examination of feces from calves and piglets with diarrhea 总被引：1，自引：1，他引：0 
下载免费PDF全文
下载免费PDF全文 Durham PJ Hassard LE Norman GR Yemen RL 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(11):876-881
A total of 763 fecal or intestinal samples from diarrheic calves and piglets were examined for viral content by immunofluorescence, electron microscopy or cell culture. Routine fluorescent antibody and cultural tests detected rotavirus (n=126), coronavirus (n=80) and bovine viral diarrhea virus (n=13). Electron microscopy detected rotaviruses (n=24) and coronaviruses (n=17) not identified by standard fluorescent antibody tests. Other viruses detected by electron microscopy included Breda virus-like particles (n=49), astroviruses (n=1), caliciviruses (n=1), rhabdoviruses (n=1), parvoviruses (n=2), enteroviruses (n=3), togavirus-like particles (n=2), and “chained” particles (n=5). Mixtures of several of the viruses were detected in a number of fecal samples.
The survey emphasized the value of electron microscopy as a broad-spectrum diagnostic tool.
相似文献994.
995.
Gough JF 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(8):672-674
Outbreaks of budgerigar fledgling disease (BFD) occurred in three budgerigar aviaries in Ontario. Acute death in seven to ten-day-old nestlings and feather abnormalities in birds over three weeks of age were common findings. Ascites, hepatomegaly and hydropericardium were prominent gross lesions. Histologically, basophilic intranuclear inclusions were seen in many tissues. A severe drop in hatchability occurred in one aviary—a finding not previously reported with BFD. Interruption of breeding controlled the disease in aviary 1, but failed in two consecutive attempts in aviary 2. A third outbreak occurred in aviary 2 after depopulation and restocking. In aviary 3, the spread of disease was very rapid; 90% of the nestlings died within a few weeks. A papovavirus similar to a previously described isolate was recovered in this outbreak. 相似文献
996.
997.
998.
999.
1000.