全文获取类型
收费全文 | 753篇 |
免费 | 21篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 128篇 |
金属工艺 | 5篇 |
机械仪表 | 24篇 |
建筑科学 | 27篇 |
矿业工程 | 1篇 |
能源动力 | 10篇 |
轻工业 | 49篇 |
水利工程 | 16篇 |
石油天然气 | 3篇 |
无线电 | 48篇 |
一般工业技术 | 108篇 |
冶金工业 | 292篇 |
自动化技术 | 54篇 |
出版年
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 21篇 |
2012年 | 18篇 |
2011年 | 26篇 |
2010年 | 27篇 |
2009年 | 11篇 |
2008年 | 13篇 |
2007年 | 18篇 |
2006年 | 20篇 |
2005年 | 28篇 |
2004年 | 12篇 |
2003年 | 19篇 |
2002年 | 22篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 19篇 |
1998年 | 82篇 |
1997年 | 51篇 |
1996年 | 40篇 |
1995年 | 21篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 8篇 |
1991年 | 17篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有774条查询结果,搜索用时 0 毫秒
81.
Determination of Stress Concentration Factors for Holes in Cylinders Using Thermoelastic Stress Analysis 总被引:1,自引:0,他引:1
Thermoelastic stress analysis is used to obtain the stress concentration factors (SCFs) from a variety of circular holes in cylinders. The cylinders are loaded in uniaxial tension, uniaxial compression and a combination of bending and compression. Firstly, radial holes are investigated and the results from the thermoelastic data obtained by the SPATE equipment are compared with previous experimental and numerical work. SCFs are then obtained from offset, oblique and offset–oblique holes using the Deltatherm system. The effect of hole obliquity and direction of applied load relative to the hole geometry are discussed in detail. Finally, the results from the cylinders are compared with predictions of the SCFs in cylinders from a previous study of oblique holes in flat plates. 相似文献
82.
S Gilman PA Low N Quinn A Albanese Y Ben-Shlomo CJ Fowler H Kaufmann T Klockgether AE Lang PL Lantos I Litvan CJ Mathias E Oliver D Robertson I Schatz GK Wenning 《Canadian Metallurgical Quarterly》1998,74(2-3):189-192
We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation. 相似文献
83.
ML Doherty ML Monaghan HF Bassett PJ Quinn WC Davis 《Canadian Metallurgical Quarterly》1996,49(4):307-320
Nine M. bovis-infected cattle on a diet deficient in both protein and energy for 133 days lost approximately 17% of their original body weight. However, dietary restriction did not result in any significant reduction in skin sensitivity to PPD, in vitro production of IFN-gamma or lymphocyte blastogenesis. The number of circulating BoCD4+ cells and B cells were similar in both the malnourished and the control cattle. However, significantly lower numbers (P < 0.01) of circulating BoCD2+ cells, BoCD8+ cells, WC1+ gamma delta T cells and ACT2+ cells were found in the malnourished cattle. With the exception of inorganic phosphate, the changes in plasma biochemical parameters were unremarkable. 相似文献
84.
85.
86.
MA Quinn 《Canadian Metallurgical Quarterly》1998,27(5):662-665
Sixteen ruptured extensor tendons were repaired in seven rheumatoid hands using autogenous palmaris longus tendon as a free interposition graft. The patients were reviewed at an average of 17 months (range, 5-45) after repair. Subjectively all patients were satisfied with the clinical results, and achieved a return to their level of ability before tendon rupture. A biomechanical model suggests that tendon repair using an interposition graft, rather than a traditional end-to-side tendon transfer retains the anatomical axis of tendon function, and achieves greater forces during active finger extension. 相似文献
87.
To identify regions of the ryanodine receptor (RyR) important for ion conduction we modified the channel with sulfhydryl-reacting compounds. After addition of methanethiosulfonate (MTS) compounds channel conductance was decreased while other channel properties, including channel regulation by ATP, caffeine, or Ca, were unaffected. The site of action was accessible to the MTS compounds from the cytoplasmic, but not the luminal, side of the channel. In addition, the hydrophilic MTS compounds were only effective when the channel was open, suggesting that the compounds covalently modify the channel from within the water-filled ion conducting pathway. The decrease in channel current amplitude occurred in a step-wise fashion and was irreversible and cumulative over time, eventually leading to the complete block of channel current. However, the time required for each consecutive modification during continuous exposure to the MTS compounds increased, suggesting that successive modification by the MTS compounds is not independent. These results are consistent with the hypothesis that the channel forms a wide vestibule on the cytoplasmic side and contains a much smaller opening on the luminal side. Furthermore, our results indicate that the MTS compounds can serve as functional markers for specific residues of the RyR to be identified in molecular studies. 相似文献
88.
Martin I.F. Schneider A.M. Quinn M.L. Smith N.T. 《IEEE transactions on bio-medical engineering》1992,39(4):381-388
A dual approach to adaptive control of arterial blood pressure using sodium nitroprusside is presented. In the clinical environment, a controller must be aggressive to achieve specific step response characteristics (less than 10 min setting time, less than 10 mm Hg overshoot), yet conservative enough to prevent overreactions to large disturbances, which are common in both the operating room and the intensive care unit. These mutually exclusive requirements make it difficult to design a closed-loop controller for this environment. To prevent possible overreactions while maintaining proper step response, an aggressive adaptive controller has been designed to achieve the desired step response, and a supervisor has been designed around the adaptive controller to limit potential overreactions in the presence of disturbances. Simulations and dog experiments demonstrate the potential for increased safety and efficacy using this dual approach to the control of a complex physiological system 相似文献
89.
JP Bellack P Gerrity SM Moore J Novotny D Quinn L Norman DC Harper 《Canadian Metallurgical Quarterly》1997,18(6):308-315
Over the last 30 years, nursing faculty have achieved varying levels of success in their efforts to engage in interdisciplinary education. To sharpen the focus, the Institute for Healthcare Improvement sponsored a national demonstration project in which nursing faculty from four universities participated. 相似文献
90.
JV Quinn A Cwinn B Carr S Grahovac I Stiell P Pelland 《Canadian Metallurgical Quarterly》1995,2(7):610-614
OBJECTIVE: To determine whether lead-lined acrylic cervical filters can improve the quality of portable lateral cervical spine (c-spine) radiographs for trauma patients. METHODS: Twenty trauma patients who required portable c-spine x-rays had these taken with a lead filter attached to the collimator of the portable x-ray machine to improve penetration and visualization of lower cervical structures without overpenetrating upper cervical structures. The radiographs of these patients were compared with the first portable c-spine radiographs without filters for 20 controls matched for gender and injury severity. The comparison of radiographs was done by an experienced emergency physician and a neuroradiologist blinded to whether the filter was used. RESULTS: The two groups were similar for demographic and clinical characteristics. There was a significant improvement in the ability to visualize the C7-T1 level for the filter group compared with the control group (65% vs 30%, p < 0.05). Agreement between the physicians was excellent (kappa = 0.79, 95% CI = 0.60-0.99). CONCLUSIONS: Lead-lined acrylic filters improve the ability to visualize the lower c-spine in trauma patients. 相似文献