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   93197篇
  免费   5199篇
  国内免费   317篇
林业   4800篇
农学   3163篇
基础科学   561篇
  12621篇
综合类   15313篇
农作物   3652篇
水产渔业   4695篇
畜牧兽医   46418篇
园艺   1110篇
植物保护   6380篇
  2021年   826篇
  2020年   854篇
  2019年   980篇
  2018年   1772篇
  2017年   1927篇
  2016年   1743篇
  2015年   1465篇
  2014年   1818篇
  2013年   3881篇
  2012年   3206篇
  2011年   3501篇
  2010年   2287篇
  2009年   2382篇
  2008年   3358篇
  2007年   3174篇
  2006年   2937篇
  2005年   2710篇
  2004年   2556篇
  2003年   2504篇
  2002年   2274篇
  2001年   2752篇
  2000年   2686篇
  1999年   2164篇
  1998年   841篇
  1997年   873篇
  1996年   819篇
  1995年   884篇
  1994年   797篇
  1992年   1602篇
  1991年   1721篇
  1990年   1596篇
  1989年   1648篇
  1988年   1541篇
  1987年   1539篇
  1986年   1563篇
  1985年   1499篇
  1984年   1196篇
  1983年   1075篇
  1979年   1241篇
  1978年   1005篇
  1977年   868篇
  1976年   827篇
  1975年   896篇
  1974年   1187篇
  1973年   1096篇
  1972年   1142篇
  1971年   1036篇
  1970年   957篇
  1969年   972篇
  1967年   854篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Abstract. A humoral antibody response was demonstrated by ELISA in rainbow trout immunized intraperitoneally with extracts from the branchiuran ectoparasite Argulus foliaceus. A similar immunization protocol produced a higher titre response in a rabbit. Both trout and rabbit identified several antigenic components on immunoblots. ELISA and immunoblotting indicated that rainbow trout and rabbit anti-A. foliaceus sera identified components from the parasitic copepods Lepeophtheirus salmonis and Caligus elongatus.  相似文献   
2.
The crossreactivity of mouse monoclonal antibodies (MoAbs) (Tab. I) prepared against human HLA-DR and HLA-DP antigens was studied in various bovine cells: lymphocytes from lymph nodes and peripheral blood, adherent (B) and nonadherent (T) lymphocytes, monocytes, granulocytes and platelets. In the immunofluorescence test, MoAbs Bra13, Bra14, Bra20, Bra22, Bra30, Bra70, HL-38 reacted with bovine B lymphocytes and monocytes, but not with other tested cells (Tab. III, IV). These antibodies, except Bra22, were positive with B lymphocytes in the complement dependent cytotoxic test (Tab. II). The similarity of the bovine antigens and HLA-DR antigens determined by used MoAbs was also proved by immunoblotting. Monoclonal antibodies Bra38 and BraFB6 did not react with the bovine cells and separated antigens. The epitope (HLA-DR) recognized by the antibody Bra38 is probably absent in cattle. The presence of HLA-DP analogue determined by the antibody BraFB6 has not been confirmed. The crossreactive MoAbs could be used for the detection of B lymphocytes and macrophages in veterinary immunology.  相似文献   
3.
4.
Mid-storage hydration-dehydration treatments with medium-vigour lettuce seed very effectively reduced physiological deterioration in storage and ultimately showed better field emergence and final yield. Soaking-drying treatment of high-vigour lettuce seed was not effective. Pre-sowing treatment of medium-vigour lettuce seed, though less effective than mid-storage treatment, gave better field performance, but high-vigour seed did not benefit from the treatment. For carrot, both mid-storage and pre-sowing seed treatments proved beneficial, with the former showing better performance than the latter. Unlike lettuce, well-preserved carrot seed responded positively to the pre-sowing treatment.  相似文献   
5.
6.
7.
8.
9.
10.
Disseminated Aspergillus terreus infection was diagnosed in ten previously healthy adult dogs--nine German shepherds and one dalmatian. The disease was characterized by the presence of multiple granulomas and infarcts in a wide range of organs. The kidney, spleen, and skeletal system were most commonly and severely affected. Fungal hyphae were demonstrated in large numbers within granulomas and thrombi, and A. terreus was readily isolated by culture. This disseminated mycosis appears unique; in this series of cases there was no apparent predisposing factor, portal of entry, or primary focus for dissemination of the infection.  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