全文获取类型
收费全文 | 6597篇 |
免费 | 4篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 45篇 |
机械仪表 | 6篇 |
建筑科学 | 7篇 |
能源动力 | 4篇 |
轻工业 | 25篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 6篇 |
冶金工业 | 6475篇 |
自动化技术 | 17篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 15篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2003年 | 11篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 158篇 |
1998年 | 1927篇 |
1997年 | 1137篇 |
1996年 | 758篇 |
1995年 | 387篇 |
1994年 | 346篇 |
1993年 | 387篇 |
1992年 | 49篇 |
1991年 | 101篇 |
1990年 | 104篇 |
1989年 | 89篇 |
1988年 | 101篇 |
1987年 | 88篇 |
1986年 | 76篇 |
1985年 | 60篇 |
1984年 | 1篇 |
1983年 | 12篇 |
1982年 | 32篇 |
1981年 | 48篇 |
1980年 | 58篇 |
1978年 | 26篇 |
1977年 | 180篇 |
1976年 | 350篇 |
1975年 | 10篇 |
1955年 | 4篇 |
1954年 | 3篇 |
排序方式: 共有6601条查询结果,搜索用时 15 毫秒
141.
142.
143.
L Larvol JP Cervoni M Besnier L Dupouet H Beaufils JP Clauvel H Levecq 《Canadian Metallurgical Quarterly》1998,22(6-7):639-641
A 24-year-old woman suffered from ano-rectal Crohn's disease and nephrotic syndrome due to glomerular amyloidosis AA. She received azathioprine and colchicine for two years. Both Crohn's disease and nephrotic syndrome resolved. However amyloid renal lesions were still present. This course is exceptional, and leads to a discussion of the treatment of amyloidosis associated with Crohn's disease. 相似文献
144.
Fifty-eight new anonymous simple sequence repeats (SSR) were generated and mapped to various rat chromosomes. Among them two genes (rat homologs for human cadherin-14 and mouse fibroblast growth factor-related protein) were mapped on Chromosomes (Chrs) 2 and 11 respectively. The majority of markers were generated from a small insert genomic library specific to Chr 11, 13, 14, and 15. Twenty new markers were mapped to Chr 13, which is known to contain a blood pressure quantitative trait locus (QTL). Several approaches to obtain microsatellite markers are described. The protocols and newly generated markers should be useful for ongoing rat genome project. 相似文献
145.
J Tonetti L Carrat S Lavalleé L Pittet P Merloz JP Chirossel 《Canadian Metallurgical Quarterly》1998,(354):103-110
A computer assisted technique of iliosacral screw placement that is applicable to unstable pelvic ring fractures is proposed. The goals are to operate noninvasively with a percutaneous procedure to decrease the complications of surgical exposure and to provide greater accuracy in locating the close neurovascular structures. Preoperative computed tomographic images of the pelvis are provided and a computed tomography three-dimensional model is built. In this model, the optimal trajectories for the drilling are planned. An ultrasound based registration is performed intraoperatively. This registration is the most original part of this work. After performing the passive drilling guidance step, the surgeon places the screws. The accuracy of the ultrasound based registration is checked by comparison with a standard surface based registration at the end of the test experiment. Each screw position is verified by a computed tomographic examination. Four human anatomic specimen pelves were tested with three screw insertions for each pelvis (12 screws). All of the screws were considered to be placed correctly. The method is safe and encourages the start of clinical application. 相似文献
146.
GW Mathern JK Pretorius HI Kornblum D Mendoza A Lozada JP Leite L Chimelli DE Born I Fried AC Sakamoto JA Assirati WJ Peacock GA Ojemann PD Adelson 《Canadian Metallurgical Quarterly》1998,5(3):151-176
This study determined whether hippocampal kainate (KA) receptor mRNA levels were increased or decreased in temporal lobe epilepsy patients compared with nonseizure autopsies. Hippocampal sclerosis (HS; n = 17), nonsclerosis (non-HS; n = 11), and autopsy hippocampi (n = 9) were studied for KA1-2 and GluR5-7 mRNA levels using semiquantitative in situ hybridization techniques, along with neuron densities. Compared with autopsy hippocampi, HS and non-HS cases showed decreased GluR5 and GluR6 hybridization densities per CA2 and/or CA3 pyramid. Furthermore, HS patients demonstrated increased KA2 and GluR5 hybridization densities per granule cell compared with autopsy hippocampi. These findings indicate that chronic temporal lobe seizures were associated with differential changes in hippocampal KA1-2 and GluR5-7 hybridization densities that vary by subfield and pathology group. In temporal lobe epilepsy patients, these results support the hypothesis that pyramidal cell GluR5 and GluR6 mRNA levels are decreased as a consequence of seizures, and in HS patients granule cell KA2 and GluR5 mRNA levels are increased in association with aberrant fascia dentata mossy fiber sprouting and/or hippocampal neuronal loss. 相似文献
147.
148.
JP Gagliardi RE Nettles DE McCarty LL Sanders GR Corey DJ Sexton 《Canadian Metallurgical Quarterly》1998,26(5):1165-1168
The effect of age on the presentation and outcome of infective endocarditis (IE) is unclear. Many of the available data are based on analyses of mixed populations of patients including intravenous drug users or those with prosthetic valve endocarditis or native valve IE. We used the Duke criteria to compare the characteristics of 44 episodes of definite native valve IE in elderly patients (> 64 years old) with the characteristics of 64 similarly defined episodes of native valve IE in younger, nonintravenous-drug-using adult patients (> 29 years and < 60 years old). Our data suggest that the clinical presentation, characteristics, and outcome of native valve IE are similar for elderly patients and younger adult patients, although elderly patients were hospitalized an average of 12 days longer. Although we found that the occurrence of renal failure and cerebral embolism during an episode of IE was associated with higher rates of death (odds ratios, 4.8 and 4.0, respectively), age was not a significant contributor to mortality. 相似文献
149.
150.