全文获取类型
| 收费全文 | 10169篇 |
| 免费 | 854篇 |
| 国内免费 | 379篇 |
专业分类
| 林业 | 401篇 |
| 农学 | 351篇 |
| 基础科学 | 244篇 |
| 873篇 | |
| 综合类 | 1301篇 |
| 农作物 | 266篇 |
| 水产渔业 | 327篇 |
| 畜牧兽医 | 7054篇 |
| 园艺 | 233篇 |
| 植物保护 | 352篇 |
出版年
| 2024年 | 30篇 |
| 2023年 | 175篇 |
| 2022年 | 177篇 |
| 2021年 | 284篇 |
| 2020年 | 439篇 |
| 2019年 | 231篇 |
| 2018年 | 341篇 |
| 2017年 | 412篇 |
| 2016年 | 295篇 |
| 2015年 | 392篇 |
| 2014年 | 525篇 |
| 2013年 | 591篇 |
| 2012年 | 618篇 |
| 2011年 | 659篇 |
| 2010年 | 502篇 |
| 2009年 | 550篇 |
| 2008年 | 463篇 |
| 2007年 | 360篇 |
| 2006年 | 296篇 |
| 2005年 | 290篇 |
| 2004年 | 290篇 |
| 2003年 | 275篇 |
| 2002年 | 255篇 |
| 2001年 | 212篇 |
| 2000年 | 167篇 |
| 1999年 | 156篇 |
| 1998年 | 189篇 |
| 1997年 | 201篇 |
| 1996年 | 178篇 |
| 1995年 | 174篇 |
| 1994年 | 145篇 |
| 1993年 | 158篇 |
| 1992年 | 188篇 |
| 1991年 | 162篇 |
| 1990年 | 198篇 |
| 1989年 | 140篇 |
| 1988年 | 123篇 |
| 1987年 | 154篇 |
| 1986年 | 58篇 |
| 1985年 | 79篇 |
| 1984年 | 84篇 |
| 1983年 | 83篇 |
| 1982年 | 40篇 |
| 1981年 | 15篇 |
| 1980年 | 5篇 |
| 1974年 | 3篇 |
| 1972年 | 4篇 |
| 1962年 | 4篇 |
| 1958年 | 3篇 |
| 1956年 | 3篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
81.
82.
Benny J. Woody DVM MS Michael J. Murphy DVM PhD AIlen C. Ray PhD Robert A. Green DVM PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1992,6(1):23-28
The clinical signs and laboratory changes of brodifacoum (BDF) intoxicated dogs and their response to vitamin K1 treatment were examined. Brodifacoum, a second-generation anticoagulant rodenticide, was fed to four dogs for 3 consecutive days producing a cumulative dose of 1.1 mg BDF/kg body weight. Clinical observations of the animals were made daily throughout the study. Monitored laboratory parameters included: one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), activated coagulation time (ACT), complete blood counts, thrombocyte counts, and serum chemistry values. Response to vitamin K1 therapy was evaluated clinically and by laboratory tests. Serum BDF concentrations were monitored. Inappetence and hemorrhagic tendencies were exhibited by day 5 postrodenticide exposure. One-stage prothrombin time, APTT, and ACT were 25% greater than time zero values at 24, 24, and 72 hours postdosing, respectively. All laboratory parameters returned to normal within 48 hours of initiating vitamin K1 therapy (0.83 mg/kg orally, TID for 5 days). Serum brodifacoum concentrations were highest (1065-1215 ng/mL) during the 3 days after BDF dosing and were detectable (3.0-7.5 ng/mL) until day 24 postexposure. A mean BDF elimination half-life of 6 +/- 4 days was observed. 相似文献
83.
84.
85.
86.
87.
Jezie A. Acorda DVM Magr Haruo Yamada DVM DVSc Seyed Mehdi Ghamsari DVM 《Veterinary radiology & ultrasound》1994,35(3):196-200
Ultrasonography of the liver was performed in 200 Holstein-Friesian dairy cattle using a 3.5 MHz transducer with a linear array electronic scanner. Liver samples were taken, processed and examined microscopically and the fat occupying rate was calculated. The hepatic ultrasonograms were evaluated according to the presence of bright pattern, dark pattern, deep attenuation, vascular blurring and blurring of edges. Of the 200 animals, 96 had a normal liver, 63 had hydropic degeneration of the liver, 37 had fatty infiltration of the liver, 3 had liver dystrophy and I had hepatic amyloidosis, diagnosed through histopathological examination. Amyloidosis was characterized by bright pattern and blurring of edges. Liver dystrophy had higher percentages of bright pattern and blurring of edges than normal liver. Hydropic degeneration had higher percentages of dark pattern and blurring of edges than normal liver. Fatty infiltration had higher percentages of bright pattern, deep attenuation, vascular blurring and blurring of edges than normal liver. The present results suggest that different ultrasonographic patterns can be observed in various diffuse hepatocellular disorders in dairy cattle 相似文献
88.
David A. Detweiler David S. Biller DVM James J. Hoskinson DVM Kenneth R. Harkin DVM 《Veterinary radiology & ultrasound》2001,42(2):108-112
Canine dysautonomia is an idiopathic condition resulting in loss of autonomic nervous system function. Recently, the prevalence of dogs diagnosed with dysautonomia in the mid-western United States has increased. In this study the medical records and radiographic findings in 24 dogs with dysautonomia were reviewed. A diagnosis of dysautonomia was made in 17 (71%) of the dogs in this study by postmortem examination, the remaining 7 (29%) dogs were diagnosed pharmacologically. The radiographic findings supportive of dysautonomia include aspiration pneumonia, megaesophagus, or a distended stomach, small bowel, or urinary bladder. In some instances, the disease radiographically mimicked other disorders of the gastrointestinal tract, including mechanical obstruction. 相似文献
89.
Susan J. Holcombe VMD MS Alicia L. Bertone DVM PhD David S. Biller DVM Valerie Haider DVM 《Veterinary radiology & ultrasound》1995,36(2):119-125
The purpose of this study was to define normal gross anatomic structures in the equine stifle with magnetic resonance images. Magnetic resonance (MR) images were made in sagittal, 15° supinated, transverse, and dorsal planes of two equine stifles. The MR images were scrutinized by comparing MR images to dissection specimens and frozen cross sections of stifle joints. Sagittal and 15° supinated images were the most valuable in assessing articular cartilage, subchondral bone, and soft tissue structures within the joint. Cranial and caudal cruciate ligaments, medial and lateral menisci, meniscotibial and meniscofemoral ligaments, long digital extensor tendon, and patellar ligaments were easily evaluated. MR images provided substantially more gross anatomical information than the currently available imaging modalities. 相似文献
90.
Samuel Jakovljevic DVM MSc DVR Nicole MacLaren DVM 《Veterinary radiology & ultrasound》1995,36(5):457-457