全文获取类型
收费全文 | 13643篇 |
免费 | 976篇 |
国内免费 | 832篇 |
专业分类
林业 | 642篇 |
农学 | 832篇 |
基础科学 | 145篇 |
354篇 | |
综合类 | 4388篇 |
农作物 | 778篇 |
水产渔业 | 930篇 |
畜牧兽医 | 4951篇 |
园艺 | 641篇 |
植物保护 | 1790篇 |
出版年
2024年 | 82篇 |
2023年 | 261篇 |
2022年 | 442篇 |
2021年 | 548篇 |
2020年 | 542篇 |
2019年 | 615篇 |
2018年 | 406篇 |
2017年 | 518篇 |
2016年 | 540篇 |
2015年 | 537篇 |
2014年 | 732篇 |
2013年 | 736篇 |
2012年 | 882篇 |
2011年 | 860篇 |
2010年 | 737篇 |
2009年 | 738篇 |
2008年 | 666篇 |
2007年 | 682篇 |
2006年 | 638篇 |
2005年 | 501篇 |
2004年 | 473篇 |
2003年 | 374篇 |
2002年 | 306篇 |
2001年 | 355篇 |
2000年 | 358篇 |
1999年 | 300篇 |
1998年 | 206篇 |
1997年 | 168篇 |
1996年 | 155篇 |
1995年 | 162篇 |
1994年 | 139篇 |
1993年 | 130篇 |
1992年 | 149篇 |
1991年 | 103篇 |
1990年 | 80篇 |
1989年 | 73篇 |
1988年 | 46篇 |
1987年 | 44篇 |
1986年 | 23篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 18篇 |
1981年 | 10篇 |
1980年 | 20篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1976年 | 8篇 |
1956年 | 6篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Update on the diagnosis of Haemophilus parasuis infection in pigs and novel genotyping methods 总被引:1,自引:0,他引:1
Haemophilus parasuis causes Gl?sser's disease as well as a number of other diseases in pigs. The diagnosis of H. parasuis-associated disease is usually established by clinical signs, pathological findings and bacterial isolation but diagnosis is complicated by the existence of non-virulent strains and the early colonisation of the upper respiratory tract of healthy piglets. Moreover, several strains can be found on a farm and even within a single animal so it is important to determine the specific strain that is causing the clinical outbreak. Recently, genotyping methods have been developed with the goal of correlating genotype with the degree of virulence of H. parasuis strains. The association between genotype and virulence in H. parasuis is challenging due to the lack of knowledge of the complete genomic sequence and virulence factors of this bacterium. 相似文献
85.
86.
《The Journal of Applied Poultry Research》2015,24(2):233-239
Formal systems of inquiry are of limited value when working with rural communities in developing countries. The current research used alternative systems of inquiry and learning that involved applying participatory epidemiology (PE) techniques to collect veterinary information about Newcastle disease (ND) in rural areas. Results indicated that poultry constituted the largest proportion (42.4%) of livestock species kept, and the poultry diseases that local farmers callbingiri, ciwon-sufe,dankanoman-kaji, dangari, andgurdumu are consistent with modern veterinary knowledge of Newcastle disease, respiratory disease, coccidiosis, fowl pox, and ectoparasitism, respectively.Tsuwen zaki (lion's testicle;Cucumuis pustulatus) andgarafuni (balsam pear;Momordica balsamina) are traditional remedies used to prevent Newcastle disease. Local farmers are knowledgeable about common disease that affect their poultry; they have good diagnostic abilities and can recognize clinical signs. There should be improved veterinary outreach to share some of this information via active community participation, and PE should be incorporated into state and national disease surveillance systems. 相似文献
87.
88.
Sharkey LC DeWitt S Stockman C 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2006,35(2):254-258
A 23-year-old Thoroughbred gelding was referred for the evaluation of acute onset of ataxia and depression, and a 2-day history of fever. On physical examination, the gelding was profoundly depressed and 10-12% dehydrated. The horse appeared very unstable, with a wide-based stance in the hind limbs, severe symmetric ataxia in all 4 limbs, and proprioceptive deficits in both hind limbs. Nasogastric intubation produced 4 L of brown, fetid reflux, and rectal examination revealed mild small intestinal and cecal distention. Hematologic abnormalities included neutropenia with toxic change, compatible with acute inflammation and endotoxemia, and prolonged coagulation times. Serum biochemical abnormalities included prerenal azotemia. metabolic acidosis, and electrolyte abnormalities consistent with enteritis. Blood ammonia concentration was markedly increased (406 micromol/L; reference interval 4-49 micromol/L), however, serum bile acids concentration and hepatic enzyme activities were within reference intervals. Histopathologic examination of a liver biopsy revealed no abnormalities and results of tests for several infectious agents were negative. Clinical signs resolved with correction of the dehydration and electrolyte abnormalities and with antibiotic therapy. The horse was diagnosed with hyperammonemic neuropathy associated with gastrointestinal disease. In such cases, hyperammonemia is caused by increased production of ammonia by organisms in the gastrointestinal tract in combination with increased gut permeability that facilitates ammonia absorption. 相似文献
89.
兔病毒性出血症、多杀性巴氏杆菌病、产气荚膜梭菌病(A)型三联灭活疫苗研制 总被引:1,自引:0,他引:1
对 5批兔病毒性出血症、多杀性巴氏杆菌病、产气荚膜梭菌病三联灭活疫苗进行了动物试验 ,结果表明该疫苗安全有效。近期效检对兔病毒性出血症的保护率为 1 0 0 % ,对兔多杀性巴氏杆菌病保护率为 92 % ,对产气荚膜梭菌病 (A)型保护率为 88%。在免疫期试验中 ,免疫 6个月后 ,对兔病毒性出血症保护率为 1 0 0 % ,对多杀性巴氏杆菌病的保护率为 79% ,对产气荚膜梭菌病 (A)型的保护率为 88%。在保存期试验中 ,4~ 8℃保存 1年仍有效。 相似文献
90.
病芽的不同处理对桑赤锈病流行的影响 总被引:1,自引:0,他引:1
在完全开放的自然环境中,桑赤锈病发病初期病芽的两种不同处理,对桑赤锈病流行趋势的影响是不同的,不剥除病芽处理区病情呈快速增长状态,拟合方程为:Y=5.82654-1.18242X 0.24296X2;剥除病芽处理区,病情稳定在较低水平,拟合方程为:Y=5.08598-2.6384X 0.4225X2-0.01865X3;方差分析表明,不同处理间的差异达到显著水平.二方程进行显著性检验分别达到了极显著和显著水平.说明剥除发病初期病芽对控制桑赤锈病流行效果显著,也可实现对桑赤锈病的可持续控制. 相似文献