全文获取类型
收费全文 | 875篇 |
免费 | 5篇 |
国内免费 | 17篇 |
专业分类
电工技术 | 6篇 |
综合类 | 5篇 |
化学工业 | 52篇 |
金属工艺 | 26篇 |
机械仪表 | 19篇 |
建筑科学 | 6篇 |
矿业工程 | 4篇 |
能源动力 | 1篇 |
轻工业 | 25篇 |
石油天然气 | 6篇 |
武器工业 | 1篇 |
无线电 | 150篇 |
一般工业技术 | 45篇 |
冶金工业 | 518篇 |
自动化技术 | 33篇 |
出版年
2021年 | 3篇 |
2016年 | 3篇 |
2014年 | 2篇 |
2013年 | 16篇 |
2011年 | 25篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 22篇 |
2005年 | 18篇 |
2004年 | 42篇 |
2003年 | 24篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 31篇 |
1998年 | 124篇 |
1997年 | 75篇 |
1996年 | 49篇 |
1995年 | 35篇 |
1994年 | 20篇 |
1993年 | 58篇 |
1992年 | 19篇 |
1991年 | 20篇 |
1990年 | 22篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 6篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 39篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1961年 | 3篇 |
1959年 | 2篇 |
1958年 | 3篇 |
1956年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有897条查询结果,搜索用时 171 毫秒
1.
2.
S. Vaynman R. S. Guico M. E. Fine S. J. Manganello 《Metallurgical and Materials Transactions A》1997,28(5):1274-1276
3.
NW Tomkins NN Jonsson MP Young AN Gordon KA McColl 《Canadian Metallurgical Quarterly》1997,75(10):722-723
On the basis of clinical signs and histological findings eight 9-month-old male rusa deer (Cervus timorensis) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5 degrees C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested polymerase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer. 相似文献
4.
5.
烷基水杨醛肟虽然是一种高选择性的铜萃取剂,但单独使用时,萃取相易出现沉淀;反萃时,再生有机相出现乳化物,而且两相分离时间较长.将月桂醇、仲辛醇、壬基酚三种调节剂分别加入到萃取剂中,研究其对烷基水杨醛肟萃取及反萃行为的影响.结果表明,三种调节剂均可以解决上述问题,只是使萃取能力略有降低;壬基酚加入到烷基水杨醛肟中有助于提高铜铁分离系数,可达647. 相似文献
6.
Since the advent of computed tomography (CT) traumatic intraventricular haemorrhage (IVH) has been diagnosed more often. It has reportedly been associated with a poor prognosis, but pure or solitary IVH is rare, suggesting that other lesions occurring concurrently with it may contribute to the poor outcome. In a series of 65 patients with severe head injury (GCS < or = 8), 14 (22%) had IVH on initial CT. Death rate in these 14 was 21%, not significantly different from that in patients without IVH (14%), although a significantly higher proportion of patients without IVH had a good outcome. These results suggest that mortality is related to other lesions associated with IVH rather than to IVH alone and that the presence of IVH does not necessarily lead to a poor outcome. 相似文献
7.
KE McLaughlin IN Jacobs NW Todd GS Gussack G Carlson 《Canadian Metallurgical Quarterly》1997,107(10):1322-1331
Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment. 相似文献
8.
9.
油脂氢化理论研究进展 总被引:2,自引:0,他引:2
本文从下列几个方面阐明油脂氢化理论的研究状况:(1)氢化机理的研究;(2)氢化反应动力学处理;(3)氢化反应活化能的确定;(4)氢化选择性的研究。 相似文献
10.
Gilbert Baumslag Benjamin Fine Xiaowei Xu 《Applicable Algebra in Engineering, Communication and Computing》2006,17(3-4):205-217
Several suggestions are presented for developing cryptosystems, both classical and public key, using a combination of combinatorial group theory and linear groups. In particular, the Reidemeister-Schreier rewriting process is used as a one way function. These suggestions raise further questions concerning both implementation and security that are being explored in the thesis of Xu [16]. 相似文献