全文获取类型
收费全文 | 1050篇 |
免费 | 45篇 |
专业分类
林业 | 15篇 |
农学 | 10篇 |
基础科学 | 4篇 |
79篇 | |
综合类 | 470篇 |
农作物 | 14篇 |
水产渔业 | 4篇 |
畜牧兽医 | 463篇 |
园艺 | 2篇 |
植物保护 | 34篇 |
出版年
2012年 | 53篇 |
2011年 | 68篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 63篇 |
2007年 | 56篇 |
2006年 | 56篇 |
2005年 | 60篇 |
2004年 | 67篇 |
2003年 | 51篇 |
2002年 | 56篇 |
2001年 | 47篇 |
2000年 | 60篇 |
1999年 | 29篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 15篇 |
1981年 | 7篇 |
1979年 | 5篇 |
1976年 | 4篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1963年 | 4篇 |
1955年 | 4篇 |
1954年 | 4篇 |
1942年 | 3篇 |
1899年 | 8篇 |
1898年 | 47篇 |
1897年 | 45篇 |
1896年 | 38篇 |
1895年 | 22篇 |
1893年 | 3篇 |
1892年 | 8篇 |
1885年 | 4篇 |
排序方式: 共有1095条查询结果,搜索用时 609 毫秒
51.
Bowman DD Legg W Stansfield DG 《Veterinary therapeutics : research in applied veterinary medicine》2002,3(3):286-289
Efficacy of moxidectin injection (ProHeart 6 Sustained Release Injectable for Dogs, Fort Dodge Animal Health) against naturally acquired infections of Trichuris vulpis was compared with that of milbemycin oxime/lufenuron tablets (Sentinel Flavor Tabs, Novartis Animal Health). Eighteen dogs infected with T. vulpis were ranked by egg counts and randomly allocated to treatment with moxidectin (170 micro g/kg), milbemycin (500 micro g/kg)/lufenuron (10 mg/kg), or to an untreated control group (six dogs per treatment). Dogs were euthanized for worm counting 7 days after treatment. Efficacy of milbemycin/lufenuron against T. vulpis was 99.6 %, compared with 67.5 % for moxidectin. The commercial formulation of milbemycin oxime/lufenuron provided excellent control of whipworm infection, whereas moxidectin demonstrated variable efficacy against this parasite. 相似文献
52.
Ohad DG 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(4):391; author reply 391-391; author reply 392
53.
Weese JS Kenney DG O'Connor A 《Journal of the American Veterinary Medical Association》2000,217(3):372-5, 340
A 2-week-old Toggenburg kid was evaluated for persistent diarrhea and poor body condition. The herd had high morbidity and mortality associated with diarrhea in neonatal kids. Lactose intolerance was diagnosed on the basis of results of a lactose tolerance test and glucose absorption test. Clinically normal herdmates were used as control animals. The kid responded to lactase supplementation. Cryptosporidium organisms were detected in feces of several affected kids during episodes of acute diarrhea. Lactose intolerance was presumed to have developed secondary to intestinal cryptosporidiosis. 相似文献
54.
Monoamines are important brain neurotransmitters. An investigation was carried out to determine if hypomagnesaemic tetany was associated with alterations in regional brain monoamine concentrations in bovines. The results, established in cows with normal magnesium status, demonstrated that regional differences existed in the distribution and concentration of brain monoamines in the adult bovine, which were similar to those in other species. In magnesium-deficient cows, severe hypomagnesaemia and lowered cerebrospinal fluid (CSF) magnesium concentrations were associated with significant alterations in monoamine concentrations in some brain regions. Alterations in 3,4-dihydroxyphenylalanine (DOPA) and dihydroxyphenylacetic acid (DOPAC) concentrations in the corpus striatum, and dopamine (DA) in the cerebral cortex and cerebellum were recorded. These regions play an important role in both voluntary and involuntary motor function, and therefore these alterations may play a role in the aetiology of hypomagnesaemic tetany. However, there was no significant change in DA concentrations in the corpus striatum (the main dopaminergic region in the brain) associated with hypomagnesaemia. In addition, a significantly lower norepinephrine (NE) concentration in the corpus striatum of hypomagnesaemic animals was also recorded. Norephinephrine is generally excitatory and therefore lowered NE concentrations would be expected to result in depression rather than stimulation of motor function. 相似文献
55.
56.
Six RH Sture GH Thomas CA Clemence RG Benchaoui HA Boy MG Watson P Smith DG Jernigan AD Rowan TG 《Veterinary parasitology》2000,91(3-4):321-331
A series of randomized, controlled, masked, field (veterinary patient) studies were conducted in the USA and Europe to evaluate the efficacy of selamectin, a novel macrocyclic lactone of the avermectin subclass, in the treatment of naturally acquired gastrointestinal nematode infections in cats. After confirmation of ascarid and/or hookworm infection, 298 cats of various ages and breeds were randomly assigned to treatment with selamectin (n=202) or an existing commercially approved positive-control product (n=96). Unit doses of selamectin (providing a minimum dosage of 6mgkg(-1)) were administered topically to the skin in a single spot at monthly intervals. Quantitative fecal examinations were performed on days 0 (before treatment), 30, and 60. In the selamectin-treated cats, fecal ascarid egg counts were reduced by 99.6 to 100% on day 30, and by 99.9 to 100% on day 60. Fecal hookworm egg counts were reduced by 98.3% on day 30, and by 100% on day 60 in the selamectin-treated cats. The positive-control products achieved reductions in egg counts of 96.5 to 100% (ascarids) and 98.9 to 99.9% (hookworms). These studies have shown that monthly topical administration of selamectin is safe and highly effective in the treatment of naturally acquired ascarid and hookworm infections in cats. 相似文献
57.
58.
59.
60.