全文获取类型
收费全文 | 2377篇 |
免费 | 25篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 89篇 |
金属工艺 | 12篇 |
机械仪表 | 15篇 |
建筑科学 | 32篇 |
矿业工程 | 4篇 |
能源动力 | 16篇 |
轻工业 | 34篇 |
水利工程 | 18篇 |
无线电 | 45篇 |
一般工业技术 | 98篇 |
冶金工业 | 1919篇 |
原子能技术 | 13篇 |
自动化技术 | 107篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 14篇 |
2020年 | 9篇 |
2019年 | 19篇 |
2018年 | 12篇 |
2017年 | 17篇 |
2016年 | 14篇 |
2015年 | 14篇 |
2014年 | 24篇 |
2013年 | 28篇 |
2012年 | 34篇 |
2011年 | 46篇 |
2010年 | 34篇 |
2009年 | 29篇 |
2008年 | 28篇 |
2007年 | 21篇 |
2006年 | 18篇 |
2005年 | 19篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 53篇 |
1998年 | 615篇 |
1997年 | 335篇 |
1996年 | 234篇 |
1995年 | 111篇 |
1994年 | 97篇 |
1993年 | 109篇 |
1992年 | 16篇 |
1991年 | 23篇 |
1990年 | 27篇 |
1989年 | 36篇 |
1988年 | 31篇 |
1987年 | 21篇 |
1986年 | 26篇 |
1985年 | 34篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 16篇 |
1977年 | 38篇 |
1976年 | 68篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1971年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有2405条查询结果,搜索用时 0 毫秒
101.
FC Wei HC Chen CC Chuang SH Chen 《Canadian Metallurgical Quarterly》1994,93(2):345-51; discussion 352-7
Microsurgical toe transfer is an established method for reconstruction of missing thumbs. However, there is little agreement on which of the various techniques represents the ideal transfer. Basically, selection of technique requires balancing the patient's functional needs, appearance of the reconstructed thumb, and donor-site cosmesis. Based on our experience with 103 toe-to-thumb transfers performed over the past 9 years, this paper attempts to provide guidelines for appropriate selection among the four most commonly employed toe transfer techniques (e.g., second toe, total great toe, great toe wrap-around, trimmed great toe) so that optimal results and patient's acceptance can both be achieved. 相似文献
102.
103.
104.
Three elderly patients have recently been admitted as emergencies to the Infection Unit of the Aberdeen Hospitals as presumed cases of infective gastro-enteritis. Investigation revealed the presence of a villous papilloma of the rectum in each case. 相似文献
105.
106.
Oocysts of the Weybridge and Houghton strains of Eimeria maxima and a fresh field isolate were similar and measured on average 30-9 X 22-4 mum. The Weybridge strain and the field isolate produced similar pathogenic effects in 6-week-old chickens, high doses causing 50-80% mortality and severe weight loss. The Houghton strain was slightly less pathogenic and few birds died but more oocysts were produced. With each strain, a single dose gave complete immunity to a light challenge with the homologous strain. Two or 3 immunizing doses gave complete immunity to a heavy homologous challenge but were not sufficient to protect against heterologous challenge. 相似文献
107.
108.
109.
110.
Dermal and glomerular deposition of IgA in anaphylactoid purpura 总被引:1,自引:0,他引:1
During the period of acute anaphylactoid purpura, skin biopsies were performed on 14 patients with purpuric and nonpurpuric skin. In addition, four patients had renal biopsies. Examination of the tissue by immunofluorescence to anti-human immunoglobulins IgG, IgA, IgM, and IgE, fibrin/fibrinogen, complement Clq, C4, and C3 demonstrated predominant IgA, C3, fibrin/fibrinogen in the purpuric skin and glomerulus, without Clq and C4. These immunohistochemical findings are characteristic of anaphylactoid purpura and suggest that IgA is involved in the pathogenesis of anaphylactoid purpura and may operate through the alternate pathway of the complement system. 相似文献