全文获取类型
收费全文 | 3152篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 154篇 |
金属工艺 | 68篇 |
机械仪表 | 42篇 |
建筑科学 | 21篇 |
矿业工程 | 6篇 |
能源动力 | 4篇 |
轻工业 | 56篇 |
水利工程 | 13篇 |
石油天然气 | 22篇 |
无线电 | 28篇 |
一般工业技术 | 167篇 |
冶金工业 | 2454篇 |
原子能技术 | 91篇 |
自动化技术 | 22篇 |
出版年
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 13篇 |
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 23篇 |
2016年 | 19篇 |
2015年 | 10篇 |
2014年 | 20篇 |
2013年 | 23篇 |
2012年 | 27篇 |
2011年 | 24篇 |
2010年 | 24篇 |
2009年 | 22篇 |
2008年 | 18篇 |
2007年 | 28篇 |
2006年 | 27篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 74篇 |
1998年 | 730篇 |
1997年 | 407篇 |
1996年 | 293篇 |
1995年 | 178篇 |
1994年 | 128篇 |
1993年 | 163篇 |
1992年 | 28篇 |
1991年 | 33篇 |
1990年 | 38篇 |
1989年 | 35篇 |
1988年 | 49篇 |
1987年 | 25篇 |
1986年 | 23篇 |
1985年 | 21篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 21篇 |
1981年 | 29篇 |
1980年 | 37篇 |
1978年 | 18篇 |
1977年 | 87篇 |
1976年 | 193篇 |
1975年 | 13篇 |
1974年 | 17篇 |
1973年 | 9篇 |
1972年 | 10篇 |
排序方式: 共有3162条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
AS Orlov 《Canadian Metallurgical Quarterly》1980,26(2):232-236
A method for the large scale preparation of partially desialylated human chorionic gonadotrophin suitable for human use is reported. To obtain the desired grade of desialylation and to avoid the presence of the enzyme in the modified hormone, neuraminidase coupled to Sepharose 4B was used. The preparation showed to be active in vitro (OAAD and SVW tests) and its half-life was found to be 13 min in the rat and 75 min in human beings. This desialo hCG proved to be effective in inducing ovulation in amenorrhoeic women. Among 39 induced cycles 31 ovulations and 5 pregnancies occurred. 相似文献
995.
996.
It has been demonstrated that activated C3 products might bind to lymphocyte C3 receptors and inhibit subsequent complement-dependent lymphocyte rosette formation. Sera from patients with various types of chronic glomerulonephritis (GN) have been tested in a complement-dependent rosette inhibition assay using normal donors' lymphocytes as reacting cells. Control subjects consisted of healthy donors and patients with miscellaneous renal and general diseases. Most sera of membranoproliferative GN and of systemic lupus erythematosus, and two-thirds sera of focal glomerolosclerosis patients, significantly inhibited rosette formation. Only 15-40 percent sera of patients with other types of GN were inhibitory. Serum inhibiting activity usually correlated with low serum C3 level (P less than 0.0005), although inhibition could be observed with normal serum C3. However, no correlation was found between a patient's own complement-dependent lymphocyte rosette count and his serum inhibitory activity. These results extend previous findings and suggest that the complement-dependent rosette inhibition assay can be used routinely to detect serum activated complement components either free or bound to immune complexes. 相似文献
997.
Clinical and X-ray examinations for hip dysplasias in 500 babies in one ward showed 40% wrongly positive and 5.6% wrongly negativ (silent or masked) results, control of which necessiates roentgenograms in the second or third month or coltrolled spreading immediately after birth. 相似文献
998.
999.
1000.