首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   587篇
  免费   37篇
林业   16篇
农学   2篇
基础科学   1篇
  42篇
综合类   106篇
农作物   12篇
水产渔业   38篇
畜牧兽医   385篇
园艺   1篇
植物保护   21篇
  2019年   8篇
  2018年   15篇
  2017年   8篇
  2016年   12篇
  2015年   11篇
  2014年   12篇
  2013年   21篇
  2012年   14篇
  2011年   22篇
  2010年   20篇
  2009年   35篇
  2008年   27篇
  2007年   18篇
  2006年   19篇
  2005年   20篇
  2004年   10篇
  2003年   13篇
  2002年   10篇
  2001年   21篇
  2000年   11篇
  1999年   17篇
  1998年   17篇
  1997年   12篇
  1996年   14篇
  1995年   7篇
  1994年   6篇
  1993年   8篇
  1992年   12篇
  1991年   18篇
  1990年   12篇
  1989年   8篇
  1988年   6篇
  1987年   10篇
  1986年   5篇
  1985年   10篇
  1983年   4篇
  1982年   5篇
  1980年   4篇
  1979年   6篇
  1977年   4篇
  1974年   5篇
  1973年   6篇
  1971年   8篇
  1970年   4篇
  1968年   5篇
  1967年   5篇
  1963年   5篇
  1960年   4篇
  1938年   5篇
  1936年   4篇
排序方式: 共有624条查询结果,搜索用时 15 毫秒
81.
The behavior of the sick animal is not necessarily a result of physical debilitation; it can be viewed as part of a highly organized adaptive strategy that is at times critical to survival if the animal were living in the wild state. Domestic ruminants appear to have retained this behavioral mode when they are sick. This article brings together several lines of current research about depression, appetite control, and the role of fever in facilitating an animal's ability to combat viral and bacterial infections.  相似文献   
82.
83.
84.
85.
86.
87.
A probabilistic model was developed to estimate target and non-target avian mortality associated with the application of the avicide CPTH (3-chloro-p-toluidine hydrochloride) to minimize sprouting rice damage in the southern USA. CPTH exposures for individual birds were predicted by random sampling from species-specific non-parametric distributions of bait seed consumption and CPTH residues detected on individual bait seeds. Mortality was predicted from the species-specific exposure versus mortality relationship. Individual variations in this response were captured in the model by Monte Carlo sampling from species-specific distributions of slopes and median toxicity values (LD50) for each bird. The model was used to simultaneously predict mortality (percentage of exposed population and number of birds killed/weight of consumed bait) for a target (blackbird) and non-target (mourning dove) species feeding on bait sites for up to five consecutive days.  相似文献   
88.
89.
The objective of this study was to evaluate the safety and efficacy of a purified porcine insulin zinc suspension for treating dogs with uncomplicated diabetes mellitus. Fifty-three dogs were treated for 60 days after an initial dose determination period. The means of the blood glucose concentrations during 12-hour glucose curves and the means of the blood glucose nadir concentrations during 12-hour glucose curves for all dogs were determined before beginning insulin therapy (time 0), at the end of the dose determination period (time 1), 30 days after time 1 (time 2), and 60 days after time 1 (time 3). Presence of polyuria, polydipsia, and ketonuria was determined at each time point. Adequacy of control of hyperglycemia was based on 12-hour blood glucose curves and improvement in clinical variables (results of physical examinations, historic information, polyuria, polydipsia, and ketonuria). Safety was evaluated by questionnaire, performance of physical examination, CBC, serum chemistry profile, and urinalysis. The means of the blood glucose concentrations during 12-hour glucose curves and the means of the blood glucose nadir concentrations during 12-hour glucose curves for all dogs at times 1, 2, and 3 were significantly lower compared with time 0 (P < .0001). There was a reduction in the proportion of dogs with polyuria, polydipsia, and ketonuria of 82, 86, and 80%, respectively. All of the dogs had adequate glycemic control at time 1, 66% at time 2, and 75% at time 3. At time 3, 66% of dogs required insulin injections q12h. Other than hypoglycemia, there were no important adverse effects of insulin administration. The insulin, was safe and efficacious for reducing blood glucose and clinical signs in dogs with diabetes mellitus.  相似文献   
90.
The most common treatment for urine spraying and marking in cats has been administration of long-acting progestins. Treatment with diazepam has recently been gaining favor, particularly because of reported adverse effects of progestins. Results of a clinical trial involving 20 cats indicated that diazepam was effective in eliminating or markedly reducing spraying in 11 (55%) of them. However, most cats required continuous treatment, or at least intermittent treatment, when spraying recurred. The physiologic and behavioral dependency of cats on diazepam, which presumably develops over the course of administration, may contribute to the tendency for spraying to recur once diazepam treatment is discontinued. Using data from previously published findings on progestin administration, plus additional cases, it was documented that a significantly (P less than 0.05) higher percentage of males than females responded favorably. Although the number of cases was not sufficient for a statistical comparison of diazepam vs progestin treatment with regard to male vs female, possible gender difference in the effectiveness of diazepam was not indicated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号