全文获取类型
收费全文 | 1172篇 |
免费 | 6篇 |
专业分类
电工技术 | 6篇 |
综合类 | 2篇 |
化学工业 | 35篇 |
金属工艺 | 6篇 |
机械仪表 | 4篇 |
建筑科学 | 6篇 |
矿业工程 | 2篇 |
轻工业 | 15篇 |
水利工程 | 2篇 |
无线电 | 25篇 |
一般工业技术 | 52篇 |
冶金工业 | 986篇 |
原子能技术 | 1篇 |
自动化技术 | 36篇 |
出版年
2022年 | 5篇 |
2021年 | 3篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2013年 | 7篇 |
2012年 | 9篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 20篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 29篇 |
1998年 | 275篇 |
1997年 | 178篇 |
1996年 | 104篇 |
1995年 | 56篇 |
1994年 | 61篇 |
1993年 | 60篇 |
1992年 | 9篇 |
1991年 | 13篇 |
1990年 | 17篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 23篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 29篇 |
1976年 | 87篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1968年 | 2篇 |
1965年 | 2篇 |
1943年 | 1篇 |
1942年 | 1篇 |
排序方式: 共有1178条查询结果,搜索用时 9 毫秒
1.
2.
3.
4.
5.
C Hojer G Hildebrandt H Lanfermann R Schr?der WF Haupt 《Canadian Metallurgical Quarterly》1994,129(3-4):131-139
The extent of resection in pilocytic astrocytoma of the posterior fossa often remains undefined and the indications for further treatment in incompletely resected tumours are a matter of debate. It has been also realized that the problem of hydrocephalus in patients with pilocytic astrocytoma of the posterior fossa has not yet been solved and the diagnostic impact of postoperative CT findings remains questionable. We retrospectively reviewed the data from 33 patients harbouring a pilocytic astrocytoma of the posterior fossa to evaluate the impact of surgical technique in terms of radicality and of postoperative imaging results upon prognosis and adjunctive treatment. In addition, the issue of hydrocephalus was considered and related to different treatment modalities. Thirty patients underwent surgical treatment whereas 3 had open biopsy of the tumour. Macroscopically gross total resection of the tumour was performed in 20 patients, whereas resection was partial in 10. Follow-up was obtained in 29 patients for a period which ranged between 2 and 184 months (85 months +/- 56 months). Outcome was good in 24 patients who had only slight neurological deficit and poor in 3 patients, who were severely disabled. Two patients died during the follow-up period. Recurrent tumour growth occurred in 2 cases with incompletely resected tumours. From the series presented, it was concluded that long-term follow-up with CT seems mandatory in cases with contrast-enhancing residual tumour. Recurrent tumour growth should be assumed in postsurgical patients with an enlarging area of enhancement shown in follow-up CT studies. Permanent ventriculoperitoneal shunting is required in certain patients with pre- or postoperative hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
Polystyrenes, polyacrylates, and poly(3,4-isoprenes) incorporating the hexafluorodimethylcarbinol functionality have been synthesized, characterized, and tested as microsensor coatings on a surface acoustic wave (SAW) device for dimethyl methylphosphonate (DMMP) vapor absorption sensitivity. The syntheses involved monomer functionalization and polymerization or hexafluoroacetone reaction with preformed polymer. All fluoroalcohol functionalized polymer coatings displayed sub parts per million level sensitivity with the slope of the absorption isotherm steepest at low DMMP concentrations. The order of sensitivity for the isomeric polystyrene fluoroalcohols (meta > para ? ortho) paralleled that of the relative free hydroxyl to hydrogen-bonded hydroxyl content. Strong hydrogen bonding between the fluoroalcohol polymers and DMMP vapor was observed by IR spectroscopy. Acylation of the fluoroalcohol group markedly reduced the DMMP sensitivity. 相似文献
7.
More inpatient hospital days are used for the care of diabetic foot infection than for any other diabetic sequela. Both the number of lower extremity amputations and the overall treatment cost of treating diabetic infections may be reduced by using a team approach in the care of the infected diabetic pedal wound. The authors propose an evaluation and treatment protocol of infected pedal ulcerations in an urban, community teaching institution when admitted to an established, multidisciplinary diabetic foot care team. The hospital course of 111 patients admitted with a primary diagnosis of infected pedal ulceration are retrospectively reviewed. Results revealed an average-length hospital stay of 7.4 days with a 96% limb-salvage rate. The authors suggest that in the treatment of the infected pedal wound, a diabetic foot care team with a well developed treatment protocol may yield a consistently favorable outcome and a cost-effective hospital course. 相似文献
8.
WF Shen JC Montgomery S Rozenfeld JJ Moskow HJ Lawrence AM Buchberg C Largman 《Canadian Metallurgical Quarterly》1997,17(11):6448-6458
Recent studies show that Hox homeodomain proteins from paralog groups 1 to 10 gain DNA binding specificity and affinity through cooperative binding with the divergent homeodomain protein Pbx1. However, the AbdB-like Hox proteins from paralogs 11, 12, and 13 do not interact with Pbx1a, raising the possibility of different protein partners. The Meis1 homeobox gene has 44% identity to Pbx within the homeodomain and was identified as a common site of viral integration in myeloid leukemias arising in BXH-2 mice. These integrations result in constitutive activation of Meis1. Furthermore, the Hoxa-9 gene is frequently activated by viral integration in the same BXH-2 leukemias, suggesting a biological synergy between these two distinct classes of homeodomain proteins in causing malignant transformation. We now show that the Hoxa-9 protein physically interacts with Meis1 proteins by forming heterodimeric binding complexes on a DNA target containing a Meis1 site (TGACAG) and an AbdB-like Hox site (TTTTACGAC). Hox proteins from the other AbdB-like paralogs, Hoxa-10, Hoxa-11, Hoxd-12, and Hoxb-13, also form DNA binding complexes with Meis1b, while Hox proteins from other paralogs do not appear to interact with Meis1 proteins. DNA binding complexes formed by Meis1 with Hox proteins dissociate much more slowly than DNA complexes with Meis1 alone, suggesting that Hox proteins stabilize the interactions of Meis1 proteins with their DNA targets. 相似文献
9.
Stress fracture of the sternum is a rare condition which presents as acute anterior chest pain after repetitive upper-body exercise. Two case reports are presented and it is postulated that this is an often underdiagnosed condition which should be considered in the differential diagnosis of acute chest pain in the athlete. Awareness of the injury together with meticulous clinical examination supported by good quality radiographs or isotope bone scan may lead to an increase in the diagnosis of this injury. 相似文献
10.