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   417916篇
  免费   37459篇
  国内免费   26810篇
耳鼻咽喉   3188篇
儿科学   6012篇
妇产科学   5372篇
基础医学   45912篇
口腔科学   6883篇
临床医学   56539篇
内科学   61061篇
皮肤病学   4822篇
神经病学   22153篇
特种医学   15412篇
外国民族医学   225篇
外科学   38993篇
综合类   71769篇
现状与发展   87篇
一般理论   32篇
预防医学   29796篇
眼科学   11176篇
药学   44326篇
  439篇
中国医学   25208篇
肿瘤学   32780篇
  2024年   1340篇
  2023年   5797篇
  2022年   15286篇
  2021年   19751篇
  2020年   15291篇
  2019年   12685篇
  2018年   13277篇
  2017年   12609篇
  2016年   11763篇
  2015年   18052篇
  2014年   22585篇
  2013年   21110篇
  2012年   31011篇
  2011年   34560篇
  2010年   23129篇
  2009年   19016篇
  2008年   23691篇
  2007年   23479篇
  2006年   22318篇
  2005年   21267篇
  2004年   14594篇
  2003年   13872篇
  2002年   11488篇
  2001年   9915篇
  2000年   9640篇
  1999年   9617篇
  1998年   5732篇
  1997年   5417篇
  1996年   4306篇
  1995年   3980篇
  1994年   3380篇
  1993年   2234篇
  1992年   3090篇
  1991年   2690篇
  1990年   2326篇
  1989年   2098篇
  1988年   1734篇
  1987年   1600篇
  1986年   1351篇
  1985年   990篇
  1984年   628篇
  1983年   480篇
  1982年   258篇
  1981年   262篇
  1980年   204篇
  1979年   363篇
  1978年   199篇
  1977年   162篇
  1974年   164篇
  1973年   162篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
运用文献计量分分析法对本刊1992-1995年16期所刊文章作了分析。结果:致突变的文章较多;每篇文章作者平均3.94人,大多集中在高等院校及科研机构,地区分布较广,高产作家尚少;平均引文8.22篇,引文以中、英文期刊为主;文献半衰期为中文4.16年,英文6.93年;有8种核心期刊;自引率较高。与创刊后的前12期(1989-1992)相比:一次性文献比重明显增加,致畸文章比重增加,高产作家相对增多,英文引文增加,英文半衰期缩短近二年半,提示刊物水平有提高趋势。  相似文献   
993.
The role of aminophylline in the re-formation of peritoneal adhesions was considered in 23 rats. Since the adhesions were obtained, the animals were subsequently divided into three groups, the first one containing seven units, the others containing eight animals each. During the four days prior the surgery, allopurinol at the dose of 50 mg/kg/die was added to the regular ground laboratory chow in the animals of the second group; aminophylline at the dose of 40 mg/kg/die was administered four hours and immediately prior the surgery, to the animals of the third group. The adhesions that we observed, were graded and evaluated assigning them a score. At the moment of the lysis of adhesions, we observed the score of 2.71 +/- 1.11 in the first group, 3.12 +/- 1.13 in the second group, and 2.75 +/- 1.03 in the third one. Matching each group one another no statistically significant difference was found. At the end the experiment, we observed a score of 3.71 +/- 0.49 for the adhesions in the first group, 2 +/- 0.75 in the second group, and 3.87 +/- 0.35 in the third one. Matching these scores with those observed at the moment of their lysis, they appeared significantly higher in the animals of the first group (p less than 0.02) and of the third group (p less than 0.05), but they were lower in the second group (p less than 0.05). Such results indicate that the re-formation of peritoneal adhesions following their lysis is constant, that allopurinol decreases the intensity of the process, while aminophylline increases it.  相似文献   
994.
995.
颞颌关节继发性滑膜炎的临床诊断   总被引:5,自引:0,他引:5  
颞颌关节滑膜炎分为原发性和继发性两种,颞颌关节紊乱综合症的滑膜炎为继发性滑膜炎。本文通过对106例颞颌关节紊乱综合症患者的临床检查、关节许氏位以及关节上腔造影的X线检查,同时对42例进行了关节内窥镜检查,在此基础上探讨了继发性滑膜炎的临床诊断标准.作者认为急性滑膜炎主要是以关节疼痛和滑膜血管的改变为主,慢性滑膜炎的临床症状与滑膜组织改变以及关节骨组织的改变均有关系。  相似文献   
996.
本文研究了竹红菌甲素(简称甲素)对S-180肿瘤细胞膜的作用。结果表明,甲素结合光照可引起S-180肿瘤细胞膜蛋白质交联、脂质过氧化产物MDA含量增加。但在SDS-PAGE分析中观察到的高分子蛋白质交联带并非由MDA所引起。甲素同样可引起小牛胸腺组蛋白光氧化、发生分子交联,并可敏化色氨酸、酪氨酸和组氨酸的无氧化。  相似文献   
997.
Frictional transition of pesticides from protective clothing   总被引:1,自引:0,他引:1  
Frictional transition of pesticides, the transition of the dried pesticide due to rubbing, from protective clothing was investigated by using an AATCC standard crockmeter. One insecticide (carbaryl) and two herbicides (atrazine and metolachlor) were studied, together with three protective clothing materials [cotton, polyester, and polyester/cotton (65/35) blend] and three crock fabrics (cotton, nylon, and silk). The effects of the properties of pesticide, fabrics, water, and perspiration on the frictional transition are discussed. The experiment showed that up to 12% of the pesticide could transfer from contaminated protective clothing to the skin through rubbing. Choosing the right materials for protective clothing and underwear would greatly decrease the frictional transition of the pesticide.  相似文献   
998.
Radix Tripterygium wilfordii Hook-F (TW) is a Chinese herbal medicine that has been reported to be effective in the treatment of various autoimmune disorders in experimental animals and man. Little is known about the immunosuppressive mechanism of action of this medicine. We demonstrate herein that TW is capable of inhibiting several afferent immune functions including the in vitro response of human peripheral blood mononuclear cells to both mitogen and alloantigen, and the generation of cytotoxic T cells. This inhibition is likely mediated through a reduction in both IL-2 production and IL-2 responsiveness. TW evidenced little capability of impairing IL-2 receptor expression, or efferent immune mechanisms such as cell-mediated cytotoxicity or natural killer cell-mediated cytotoxicity. The immunosuppressive effects of TW were reversible except at the highest concentration tested, 2.4 micrograms/ml, and there was no evidence of TW-mediated cell-well damage as evidenced by trypan-blue exclusion. TW, or some of its constituents, may be important new agents to be studied for immunosuppression in organ transplantation.  相似文献   
999.
采用高效液相色谱法测定了异丙酚在不同温度下及其甲醇 水(V∶V=70∶30)混合溶液在不同pH值下的反应速率常数,并求出了异丙酚氧化反应的活化能,结果表明pH值与温度对异丙酚的氧化动力学均有影响  相似文献   
1000.
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