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   3312篇
  免费   153篇
  国内免费   3篇
林业   235篇
农学   465篇
基础科学   87篇
  852篇
综合类   86篇
农作物   275篇
水产渔业   70篇
畜牧兽医   1015篇
园艺   98篇
植物保护   285篇
  2023年   23篇
  2022年   36篇
  2021年   49篇
  2020年   87篇
  2019年   87篇
  2018年   120篇
  2017年   140篇
  2016年   113篇
  2015年   87篇
  2014年   98篇
  2013年   305篇
  2012年   141篇
  2011年   158篇
  2010年   126篇
  2009年   115篇
  2008年   113篇
  2007年   141篇
  2006年   146篇
  2005年   111篇
  2004年   71篇
  2003年   78篇
  2002年   72篇
  2001年   57篇
  2000年   51篇
  1999年   53篇
  1998年   41篇
  1997年   44篇
  1996年   35篇
  1995年   34篇
  1994年   31篇
  1993年   28篇
  1992年   30篇
  1991年   36篇
  1990年   32篇
  1989年   38篇
  1988年   45篇
  1987年   34篇
  1986年   29篇
  1985年   24篇
  1984年   25篇
  1983年   26篇
  1982年   22篇
  1980年   34篇
  1979年   37篇
  1978年   20篇
  1976年   20篇
  1971年   20篇
  1970年   37篇
  1969年   24篇
  1968年   23篇
排序方式: 共有3468条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
TREATMENT OF DIAPHRAGMATIC HERNIA IN BUFFALOES   总被引:2,自引:0,他引:2  
The surgical treatment of diaphragmatic hernia attempted on 19 lactating buffaloes is described. Thirteen cases recovered uneventfully, 1 recovered after developing brisket oedema and 5 died, 3 during surgery and 2 postoperatively. The desired depth of anaesthesia was achieved by the administration of 6% chloral hydrate followed by 5% thiopentone sodium. A postxiphoid approach and the use of a continuous lock stitch suture were preferred to repair the vent in the diaphragm. Pre- and post-operative use of hydrocortisones and fluids and sufficient tissue oxygenation by controlled positive pressure respiration are believed to be keys to the success of the treatment adopted.  相似文献   
106.
Contrast radiography of the alimentary canal was conducted in six adult sheep with barium sulfate (70% W/V, 25–30 ml/kg). A period of 12 hours was adequate for opacification of most parts of the gastrointestinal tract. The presence of contrast medium in different parts of the alimentary canal was noted for as long as 60 hours. The right lateral view was adequate for visualization of most structures, but the typical laminar mucosal pattern of the omasum and the spiral mucosal folds of the abomasum were demonstrated better on the ventrodorsal view.  相似文献   
107.
108.
A buffalo disease, called "Degnala", causing lameness, edema, gangrenous ulceration of hooves or tail, emaciation, recumbency and eventual death, occurs in Eastern Nepal. Clinical examinations manifested lice eggs on hairs, bradycardia, hypothermia, dehydration, exanthema and icterus. Hematologically, increase of band neutrophil, giant platelet, hypoalbuminemia and hyperglobulinemia were characteristics. Microscopically, dark blue tiny particles were seen on red blood cell (RBC) after Giemsa staining. Administration of tetracycline at an early stage of the disease was effective.  相似文献   
109.
110.
OBJECTIVE: To determine the effect of immunization with bovine luteinizing hormone receptor (LH-R) on ovarian function of cats. ANIMALS: 9 adult female domestic cats. PROCEDURE: 7 cats were immunized with 0.5 mg of LH-R encapsulated in a silastic subdermal implant (3 x 10 mm); 2 served as control cats. Receptors had 80% specific binding to 125I-human chorionic gonadotropin with a binding capacity of 2,682 pM/mg. Cats received booster injections of LH-R. Cats were induced to ovulate with luteinizing hormone (LH) releasing hormone on day 345. Samples of venous blood and vaginal cells were collected through day 395. Observation of estrus behavior continued until day 516. Serum concentrations of estradiol, progesterone, thyroid gland hormones, LH, and LH-R antibody were determined. RESULTS: LH-R antibody was detected in the sera of immunized cats within 21 days after implantation. Detection of LH-R antibody was associated with suppression of serum progesterone to < or = 0.5 ng/mL during the study period, compared with concentrations of 5 to 10 ng/mL in control cats. Immunized cats did not display signs of estrus. Release of LH after administration of LH-releasing hormone indicated an intact hypothalamic-pituitary axis but poor corpus luteum function. Serum estradiol concentrations remained between 30 to 40 pg/mL in immunized and control cats. With the decrease antibody titers, hormone concentrations returned to a pattern consistent with that during fertility. CONCLUSIONS AND CLINICAL RELEVANCE: Active immunization with LH-R suppressed corpus luteum function in cats. The effect was reversible. An LH-R-based antifertility vaccine may have clinical application in other vertebrates.  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