全文获取类型
收费全文 | 3575篇 |
免费 | 293篇 |
国内免费 | 2篇 |
专业分类
林业 | 138篇 |
农学 | 88篇 |
基础科学 | 15篇 |
293篇 | |
综合类 | 91篇 |
农作物 | 102篇 |
水产渔业 | 95篇 |
畜牧兽医 | 2911篇 |
园艺 | 18篇 |
植物保护 | 119篇 |
出版年
2023年 | 60篇 |
2022年 | 24篇 |
2021年 | 35篇 |
2020年 | 129篇 |
2019年 | 35篇 |
2018年 | 105篇 |
2017年 | 118篇 |
2016年 | 82篇 |
2015年 | 96篇 |
2014年 | 150篇 |
2013年 | 220篇 |
2012年 | 132篇 |
2011年 | 157篇 |
2010年 | 137篇 |
2009年 | 134篇 |
2008年 | 120篇 |
2007年 | 72篇 |
2006年 | 74篇 |
2005年 | 51篇 |
2004年 | 80篇 |
2003年 | 89篇 |
2002年 | 96篇 |
2001年 | 96篇 |
2000年 | 78篇 |
1999年 | 86篇 |
1998年 | 112篇 |
1997年 | 115篇 |
1996年 | 94篇 |
1995年 | 83篇 |
1994年 | 74篇 |
1993年 | 92篇 |
1992年 | 105篇 |
1991年 | 83篇 |
1990年 | 98篇 |
1989年 | 81篇 |
1988年 | 80篇 |
1987年 | 85篇 |
1986年 | 39篇 |
1985年 | 52篇 |
1984年 | 39篇 |
1983年 | 56篇 |
1982年 | 18篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1977年 | 9篇 |
1975年 | 7篇 |
1973年 | 9篇 |
1969年 | 7篇 |
1968年 | 7篇 |
排序方式: 共有3870条查询结果,搜索用时 46 毫秒
61.
Antinutritional effects of phytic acid (myoinositol hexaphosphate, IP6) on growth and digestibility in fish have been reported. However, specific effect of IP6 on the digestive enzymes in fish has not been addressed. In this study, inhibitory effect of synthetic IP6 (Phytic acid sodium salt, 90% purity) on the activity of the digestive protease and α‐amylase in rohu, Labeo rohita; catla, Catla catla; and mrigal, Cirrhinus mrigala has been investigated in vitro. Graded levels (12.5, 25, 50, 100, 150, and 200 µg/mL) of IP6 were added to the reaction mixtures containing enzyme extracts and substrate solution in triplicate to detect any change in enzyme activity. Results of the experiment revealed that IP6 significantly inhibit/lower activities of the digestive enzymes in a dose‐dependent manner, as evident from the regression equations (F values significant at P < 0.001 level). Apparently, irrespective of the fish species studied IP6‐induced inhibition of α‐amylase activity was greater than protease activity. Among the three fish species studied, C. mrigala appeared to be more sensitive to IP6 for both α‐amylase and protease activity. Enzyme activity was least affected in C. catla. Results of the study might raise concern while incorporating IP6 rich plant‐derived feed ingredients in aqua feed preparation. 相似文献
62.
S. Ali M. Ijaz S. H. Farooqi A. Z. Durrani M. I. Rashid A. Ghaffar A. Ali A. Rehman S. Aslam I. Khan A. Masud K. Mehmood 《Equine Veterinary Education》2021,33(2):75-83
Theileria equi (T. equi) is an obligate intra- and extra-erythrocytic parasite that causes equine theileriosis (ET) in equids. Equine theileriosis is considered a notifiable disease of global significance, a major constraint to the international movement of horses, and endemic in many countries. This disease may be difficult to diagnose, as it can produce variable and nonspecific clinical signs. A cross-sectional study was designed for the molecular characterisation of T. equi and to investigate the associated risk factors of ET accompanied by its consequences on haematological and sero-biochemical parameters. A convenience sampling of 500 blood samples were collected from ET suspect horses from January to December 2017. PCR was performed on all blood samples targeting the 18S rRNA gene of T. equi followed by sequencing; 9% animals tested positive with confirmed sequences. The isolates of this study showed high homology with Cuban, Russian and Brazilian isolates of T. equi (accession numbers KY111762.2 , MG551915.1 and KY952237.1 , respectively). Based on multivariate analysis, the principal risk factors consisted of absence of dogs on the premises and presence of tick infestation. The haemato-biochemical parameters showed a decrease in granulocytes and erythrocytes, and an increase in lymphocytes, monocytes, mean corpuscular volume, mean corpuscular haemoglobin, mean platelet volume, glucose, phosphorus and aspartate aminotransferase in positive horses. This is the first study which identified ET in Punjab (Pakistan) using molecular techniques and risk factors together with the haemato-biochemical variations in horses. 相似文献
63.
64.
Rita M. Hanel DVM DACVIM DACVECC Lee Palmer DVM MS DACVECC NREMT‐T WEMT CCRP Janice Baker DVM DACVPM Jo‐Anne Brenner BA EMT‐I EMT‐T David Dorman DVM PhD DABVT John C. Gicking DVM DACVECC Brian Gilger DVM MS DACVO DABT Cynthia M. Otto DVM PhD DACVECC DACVSMR Elizabeth Rozanski DVM DACVECC DACVIM Brian Trumpatori DVM 《Journal of Veterinary Emergency and Critical Care》2016,26(2):166-233
65.
Nutritional analysis and microbiological evaluation of commercially available enteral diets for cats
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
66.
67.
Thromboelastographic evidence of inhibition of fibrinolysis after ε‐aminocaproic acid administration in a dog with suspected acute traumatic coagulopathy
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
68.
Comparison of 4 point‐of‐care blood gas analyzers for arterial blood gas analysis in healthy dogs and dogs with cardiopulmonary disease
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
69.
70.