全文获取类型
| 收费全文 | 10120篇 |
| 免费 | 667篇 |
| 国内免费 | 50篇 |
专业分类
| 林业 | 665篇 |
| 农学 | 480篇 |
| 基础科学 | 82篇 |
| 1940篇 | |
| 综合类 | 655篇 |
| 农作物 | 526篇 |
| 水产渔业 | 795篇 |
| 畜牧兽医 | 4608篇 |
| 园艺 | 154篇 |
| 植物保护 | 932篇 |
出版年
| 2023年 | 92篇 |
| 2022年 | 154篇 |
| 2021年 | 318篇 |
| 2020年 | 325篇 |
| 2019年 | 382篇 |
| 2018年 | 349篇 |
| 2017年 | 371篇 |
| 2016年 | 394篇 |
| 2015年 | 270篇 |
| 2014年 | 385篇 |
| 2013年 | 572篇 |
| 2012年 | 619篇 |
| 2011年 | 670篇 |
| 2010年 | 349篇 |
| 2009年 | 366篇 |
| 2008年 | 530篇 |
| 2007年 | 520篇 |
| 2006年 | 460篇 |
| 2005年 | 421篇 |
| 2004年 | 380篇 |
| 2003年 | 338篇 |
| 2002年 | 380篇 |
| 2001年 | 260篇 |
| 2000年 | 254篇 |
| 1999年 | 215篇 |
| 1998年 | 68篇 |
| 1997年 | 70篇 |
| 1996年 | 60篇 |
| 1995年 | 55篇 |
| 1994年 | 43篇 |
| 1993年 | 39篇 |
| 1992年 | 82篇 |
| 1991年 | 54篇 |
| 1990年 | 63篇 |
| 1989年 | 69篇 |
| 1988年 | 65篇 |
| 1987年 | 52篇 |
| 1986年 | 46篇 |
| 1985年 | 60篇 |
| 1984年 | 37篇 |
| 1983年 | 45篇 |
| 1982年 | 30篇 |
| 1980年 | 27篇 |
| 1979年 | 40篇 |
| 1978年 | 21篇 |
| 1977年 | 21篇 |
| 1974年 | 23篇 |
| 1973年 | 25篇 |
| 1972年 | 24篇 |
| 1970年 | 26篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
991.
To study the effects of olaquindox and cyadox on aldosterone, sodium and potassium in the blood in comparison with the effects of carbadox, weaned pigs were fed these compounds in different doses. Pigs treated with 100 and 200 ppm carbadox showed a significant decline of aldosterone after five and three weeks, respectively, compared with control values. In the 200 ppm group treatment was interrupted at week 4. With olaquindox a continuous, significant decline was found from 50 ppm and above after five weeks, and from 25 ppm and above (but excluding the 100 ppm group), after six weeks. In the cyadox groups a significant decline was measured after six weeks in the 50, 200 and 400 ppm groups. Only the 200 ppm group had an earlier response at three and five weeks. A decrease of sodium to hyponatraemic levels in the carbadox groups was seen after three weeks in the 200, and after five weeks in the 100 ppm group. In the olaquindox groups only the 200 ppm dosage showed a consistent decrease to hyponatraemic levels from four weeks treatment. In the cyadox groups the 200 ppm dosage reached a hyponatraemic level after six weeks. An increase of potassium to hyperkalaemic levels occurred at 100 and 200 ppm carbadox dosage after four and three weeks, respectively, and at 200 ppm olaquindox dosage after four weeks. No hyperkalaemic levels were seen in the cyadox groups. It is concluded that the toxic effect of olaquindox, despite minor differences, is comparable with that of carbadox but that cyadox is less toxic. 相似文献
992.
W H Miller Jr C de Jaham D W Scott S M Cayatte M S Bagladi R G Buerger 《The Canadian veterinary journal. La revue veterinaire canadienne》1996,37(4):219-221
The purpose of this study was to determine the efficacy of orally administered milbemycin oxime in the treatment of canine scabies. Forty dogs were treated. Mean drug dosage for all dogs was approximately 2 mg/kg body weight. Twenty-seven dogs received 3 doses separated by 7 d, and 13 dogs received 2 doses separated by 14 d. All dogs were clinically normal following treatment and no adverse reactions were detected. 相似文献
993.
T D Scavelli W E Hornbuckle L Roth V T Rendano A de Lahunta S A Center T W French J F Zimmer 《Journal of the American Veterinary Medical Association》1986,189(3):317-325
Congenital portosystemic venous shunt causing signs of hepatic encephalopathy was diagnosed in 7 cats. The left gastric vein served as the shunt in four of these. Increases in blood ammonia and postprandial serum bile acids were the most consistent serum biochemical abnormalities. Excessive variation in red blood cell shape was a common but nonspecific hematologic finding. The jejunal-mesenteric venous injection of contrast material was the preferred method of portography to diagnose portosystemic shunts. Two cats were treated successfully by partial surgical occlusion of their shunts. 相似文献
994.
995.
996.
Heartwater. An overview of the clinical signs, susceptibility and differential diagnoses of the disease in domestic ruminants 总被引：1，自引：0，他引：1
Heartwater is a frequently fatal tick-borne disease of ruminants caused by Cowdria ruminantium. In domestic ruminants the incubation period varies considerably and depends on the route of infection, virulence of the isolate and amount of infective material administered. Adult cattle of all breeds appear to be equally susceptible to heartwater. It is generally accepted that calves up to the age of 3 weeks have a high degree of natural resistance which is not related to the immune status of the dam. Nervous symptoms are frequently seen in animals affected by the peracute and acute forms of heartwater and can easily be confused with similar signs caused by infectious conditions, toxic plants, acaricide and heavy metal poisonings. 相似文献
997.
Excretion of alcelaphine herpesvirus-1 by captive and free-living wildebeest (Connochaetes taurinus)
B J Barnard R G Bengis M D Griessel V de Vos 《The Onderstepoort journal of veterinary research》1989,56(2):131-134
Excretion of alcelaphine herpesvirus-1 (AHV-1) is for all practical purposes limited to wildebeest calves under the age of 4 months. Sixty-one per cent of calves 1-2 months of age excreted virus with a mean titre of 9.8 X 10(4) cytopathic-forming foci/ml in their ocular fluid. The incidence declined sharply to less than 2% in wildebeest older than 6 months. No difference in age-related excretion of virus could be detected between free-living and captive wildebeest and no virus could be isolated from free-living pregnant wildebeest cows or from captive cows and their calves during the first 4 weeks after birth. The occurrence of wildebeest-derived malignant catarrhal fever (WD MCF) during spring, when wildebeest do not excrete virus, is a strong indication of the existence of an alternative host or an intermediate host capable of biological transfer of AHV-1. 相似文献
998.
999.
1000.